RU2124641C1 - Steam power plant and its operation process - Google Patents

Abstract

FIELD: thermal engineering (including nuclear power engineering); steam-turbine and combined- cycle plants using any type of fuel for combined heat and power generation. SUBSTANCE: when plant is running to produce heat of high quantity for particular steaming capacity, working medium is conveyed bypassing heated side of at least one high-pressure regenerative heater, heated side of mentioned heater or heaters is changed over to heat-transfer circulating loop of heat load, and in the process boiler or steam generator capacity is either raised at its preset steaming capacity or boiler or steam generator capacity is simultaneously raised and its steaming capacity is changed according to changed range of enthalpies (and, hence, temperature) of working medium heated in boiler or steam generator. Steam power plant implementing this method has respective parts, shut-off and control valves. EFFECT: improved power and resource conservation technology. 6 cl, 7 dwg

Description

 The invention relates to the field of thermal energy (including nuclear technology), is aimed at improving energy and resource saving technologies and can be used in steam-powered, as well as in combined-cycle power plants, in which electric and thermal energy are produced simultaneously for any type of fuel for consumers given parameters.

It is known that in the process of generating only electricity at condensing steam-turbine power plants, a large amount of heat from the heater of the plant's thermodynamic cycle (up to ~ 60%) must inevitably be transferred to the cold "source" - the water cooling the condenser and, thus, it is uselessly lost. At the same time, it is known that, in addition to electricity, a significant amount of heat is used in the form of hot water and steam for various industrial processes for the production and domestic needs of consumers, as well as for heating buildings and hot water. In conventional condenser steam turbine heat power plants, to ensure maximum electrical efficiency (Efficiency), the pressure in the condenser is maintained equal to ~ 0.04 ata, that is, the condensation of the working steam occurs at a temperature of about 28-29 ^o C. The heat given off by the cooling water in such a condenser has a low temperature potential and therefore cannot be used for industrial and domestic needs, as for technological purposes, as a rule, saturated water vapor with pressure is used m from 2.5 to 20-40 ata, and for heating - saturated water vapor with a pressure of 1.5 - 2.6 ata or hot water with a temperature of up to ~ 130-180 ^o C.

 Cogeneration steam turbine plants differ from purely condensing ones in that at a relatively high pressure some part of the steam working in the turbine is diverted, which is used for heat supply purposes. In this case, the absolute electrical efficiency of the installation will slightly decrease. However, the possibility of obtaining large amounts of heat for technological and domestic needs due to a certain reduction in electricity generation is very profitable, since it eliminates the need to build special heating boilers, usually having a relatively low efficiency (~ 86-90%) and therefore require a corresponding increased (1 / efficiency times) fuel consumption, as well as irrationally using the heat of a high temperature potential when burning fuel to heat a low-temperature coolant That is unprofitable due to a decrease system performance. In this case, the economic gain when using the heat of the steam exhausted in the turbine is determined by the fact that the heat of vaporization is hidden, which in condensing plants is lost with the cooling water of the condensers, in plants built for the combined generation of heat and electricity, it is fully or partially used to cover domestic or industrial needs adjacent to the power plant area. Turbines that not only serve as the drive of the electric generator, but also provide heat to external consumers, are called cogeneration, and thermal power plants that carry out combined production of electricity and heat are called heat and power plants (CHP), in contrast to purely condensation power plants (IES) that produce only electricity. Since, as noted above, steam or water is required for industrial and domestic needs in a relatively wide range of temperatures and pressures, various designs of cogeneration turbines and steam-power (or gas-vapor) power plants including them depending on the nature of heat consumption and a given electric load are used at the CHP .

To characterize the economics of the operation of the CHPP, the so-called heat utilization coefficient K is used, which is defined as the ratio of the amount of useful work produced in the thermodynamic cycle, L _e , and the heat Q ₂ given to the external consumer, to the amount of heat Q ₁ released during the combustion of the fuel: K = (L _e + Q ₂ / Q ₁ , or, equivalently, K = (N + Q) / BQ ^p _n , where N is the electric power of the installation, B is the hourly fuel consumption, Q ^p _n is the heat of combustion of the fuel, Q - the amount of heat given to an external consumer (see, for example, the book "Technical Thermo Enamika ", V. A. Kirillin et al., M., Energoatomizdat, 1983, p. 325). The value of K is closer to unity, the more perfect the installation, that is, the less heat loss in the boiler and steam pipe, mechanical and electrical losses in the electric generator, etc.

 The simplest of the cogeneration plants works according to the known method of operation, in which the liquid phase of the working fluid of a steam-powered power plant, compressed to a certain elevated pressure, for example, is sent to a boiler or steam generator, where at constant pressure it is heated to form a set of initial parameters, which are then sent in the flow part of a steam turbine equipped with, for example, regenerative steam extraction, in which the process of its expansion takes place, as a result of which the turbine it activates the electric generator, then the steam that is spent in the turbine is sent to the heat energy consumer, after which the steam condensate is compressed by the pump and then fed back through the heated sides of the high pressure regenerative heaters to the boiler or steam generator (see, for example, the book "Fundamentals of Thermodynamics of Cycles" heat power plants ", A.I. Andryushchenko, M.," Higher School ", 1977, pp. 80-81).

 In plants operated according to the above method, the main element of the equipment is type P turbines - that is, with back pressure and without controlled steam extraction. These are, for example, turbines of the following domestic brands: P - 40-12.8 / 3.0 and P-100-12.8 / 1.3-2 (see, for example, the book "Steam Turbines", A.V. Scheglyaev, M., Energoatomizdat, 1993, book 1, pp. 91-97, book 2, pp. 216-218). At the same time, at an initial steam pressure of 130 ata, the first of the mentioned turbines gives out to the thermal consumer the steam that has been exhausted in the turbine with a pressure of 28.5-35.7 ata, and the second with a pressure of 12-21 ata. In these steam-powered power plants, the steam leaving the turbine (type P) with backpressure is consumed only in the amount that is necessary for the heat consumer. Since the electrical efficiency of such installations with constant initial steam parameters depends only on the steam flow rate (with a constant heat difference triggered in the turbine), the power of the counter-pressure turbine (and, accordingly, the electric generator driven by it) is uniquely determined by the flow rate of the steam flowing through the turbine. Therefore, steam-powered power plants based on P-type turbines are suitable for such heat consumers, the load of which is kept at a fairly high level all year round, for example, for chemical production. In this case, the pressure of the steam entering the heat consumer, as a rule, is required to be kept constant.

 However, the above method of operating a steam-powered power plant and a plant for its implementation has a disadvantage that limits their economical use. This disadvantage lies in the fact that the power plants operated by this method can efficiently serve a heat consumer using production steam with only a practically constant pressure value, while often a heat consumer requires steam of two different pressures, for example, for industrial and heating purposes.

 This drawback is deprived of the known method of operating a steam-powered power plant, in which the liquid phase of the plant’s working fluid, mainly water, is sent to a boiler or steam generator, where it is heated at constant elevated pressure until a predetermined parameter is formed, which is then sent to a two-cylinder turbine in which the process its expansion, as a result of which the turbine drives an electric generator, while part of the steam flow out of the high pressure cylinder of the turbine is sent to the industrial heat consumer, and the remaining part of the steam flow with lower pressure after leaving the second working cylinder of the turbine is directed, for example, to the heat heat consumer, after which all the condensate of the exhaust steam generated by the consumers is compressed by a pump and then again fed to the boiler or steam generator for heating and steam formation (see, for example, the book "Steam Turbines", A. V. Scheglyaev, M., Energoatomizdat, 1993, book 2, pp. 246-248).

 The main element of the equipment of the mentioned power plants are steam turbines of the PR type (cogeneration with backpressure and production steam extraction). These include, for example, the following well-known domestic turbines (see, for example, the book "Steam Turbines", A.V.Scheglyaev, M., Energoizdat, 1993, book 1, p. 76): PR-6- 35/10/5, PR-6-35 / 15/5 and PR-12 / 15-90-15 / 7. From the designations of the turbines it can be seen that they can simultaneously produce to the thermal consumer production steam with a pressure of 10 to 15 atmospheres, and also "heating" steam with a pressure of 1.2 to 7 atmospheres.

However, the specified method of operating a steam-powered power plant and a plant for its implementation have the following disadvantages:
low electric efficiency of the installation, due mainly to a significantly higher (compared to the same IES) pressure value of the main steam flow processed in a turbine that rotates the electric generator, and which then enters the heat consumer;
inefficient (incomplete) use of electrical equipment due to a significant decrease in the power of the generator associated with the turbine during periods of reduced heat consumption, for example, in the summer "unheated" time and / or during interruptions in the production consumption of the steam spent in the turbine of sufficiently high parameters;
due to the first two drawbacks, a low (average annual) value of the coefficient of heat utilization of the fuel of the installation.

 In contrast to the above, a higher value of electrical efficiency, a significantly better use of equipment, as well as a higher average annual heat utilization coefficient of fuel are provided in steam-powered power (condenser) plants based on PT, T, K turbines operating according to the generally known method CT and / or TC, and in which, due to this, the power of electric generators can vary over a wide range almost independently of the load of the heat consumer (see, for example, igu "Steam turbines", A.V. Shcheglyaev, M., Energoatomizdat, 1993, book 1: p. 71-99; book 2: p. 248-264, 294-326, 332-344, 347 -350, 356-367).

 In addition to generating electricity in the connected generators, the mentioned turbines are of type ПТ (these include domestic turbines ПТ-60 / 75-12,8 / 1,3; ПТ-80-100-12,8 / 1,3 and ПТ-135 / 162- 12.8 / 1.5) provide the possibility of simultaneous delivery to the external heat consumer of regulated production (with a pressure of 13 and 15 ata, respectively) and heating (with a pressure of from 0.5 - 1.2 to 2.5 ata) steam take-offs, and turbines type T (these include, for example, domestic turbines T-180 / 210-12.8; T-185 / 220-12.8-1 and T-250 / 300-23.5-3) provide the ability to issue heat to the consumer two adjustable in a certain pressure range of the heating steam extraction of the given parameters (from 0.5 to ~ 3.0 ata).

 In addition, K, KT and TK type turbines - these include, for example, the well-known domestic K-210-128-3 turbines (6); K-220-4.4 (3-5); K-300-23.5; K-310-23.5-3; K-320-23.5-4; K-500-17.7; K-500-23.5-4; K-500-5.9 / 25; K-800-12.8; K-800-23.5-5; K-1000-5.9 / 25-1 (2); K-1100-5.9 (25-4 (5); K-1200-23.5-3; KT-1070-5.9-25.3 and TK-450 / 500-5.9- provide the possibility of issuing to an external consumer of heat of several (for example, up to four) heating extracts of steam of unregulated pressure (up to ~ 3-5 ata).

 The well-known steam-powered power plants operating according to a fundamentally general method of operation based on the above-mentioned known turbines of types K, CT, TK, T and / or PT (see, for example, the book "Steam Turbines", A.V. Shcheglyaev, M., Energatomizdat , 1993; book 1: p. 56, fig. 1.26; book 2: p. 360, fig. 10.31, as well as the book "Heat Technical Reference", edited by V.N. Yurenev and P.D. Lebedev , M., Energy, 1975, volume 1, p. 474, 477, 478. 480, 481, 490-493) eliminates the disadvantages of the above known method of operating a steam-powered power plant as follows.

 The values of their electrical efficiency are noticeably higher (up to ~ 30-41%) due to the fact that the main steam flow entering the turbine operates in it to a significantly lower pressure, which is lower than atmospheric pressure in the condenser, and also due to the introduction into the cycle, in addition to a condenser, regenerative low-pressure steam withdrawals, which give, for example, higher fuel economy than the accepted high-pressure regenerative steam withdrawals (see, for example, the book "Fundamentals of thermodynamic cycles of thermal power plants", A.I. Andryushchenko, M. , ysshaya school, 1977, p.72).

 The use of the available capacity of the electrical equipment of the installation during its operation is significantly higher, since its power is almost not determined by the heat load of the consumer, since during the periods of reduced heat consumption (or even during the termination of heat consumption) the steam withdrawals are closed to the external heat consumer and then the entire steam flow enters in a turbine rotating an electric generator, generating, in this regard, more electricity.

 The aforementioned increases in electrical efficiency and generated electric power, together with a more independent heat load, which can be significant in magnitude (as, for example, in the KT-1070-5.9 / 25-3 power plant), provide a higher fuel heat utilization power plant.

 As a result, taking into account the statement of the problem presented below, the claimed technical solutions (method and device) are aimed at, the above and similar known steam-powered power plants (based on turbines of types K, CT, TK, T and / or PT) operate according to the general method of operation (see, for example, the book "Steam Turbines", A.V. Shcheglyaev, M., Energoatomizdat, 1993, book 1, p. 56, fig. 1.26), according to which a compressed, for example, liquid phase of the working fluid installations, mainly water, are sent to a boiler or steam generator, where at constant pressure due to the heat of the fuel, they are heated until the necessary parameters are generated, which is then sent to the flow part of the turbine equipped with regenerative steam extraction, in which the process of expansion takes place, as a result of which the turbine drives, for example, an energy generator, then exhaust the steam in the intermediate superheater, after which it is fed for further expansion and the corresponding performance of work in the next at least one working cylinder of the turbine and then the condenser, or immediately sent to the condenser, where due to cooling by an external heat carrier, the steam is converted into the liquid phase of the working fluid, which is then pumped into at least one regenerative low-pressure heater, then it is sent, if necessary, to a deaerator, then fed to the heated side of at least one surface regenerative high-pressure heater and then again sent to the boiler or steam generator of the installation, in which during its operation with delivery to the consumer also thermal energy from the turbine is additionally taken part of the flow rate of the working fluid of the installation, which is used to transfer thermal energy to the consumer.

 A steam-powered power plant for the implementation of the specified known method of operation may contain (see, for example, also in the book "Steam turbines, A.V. Scheglyaev, pr.1. P. 56, Fig. 1.26) combined, for example, by pipelines of the circulation of the working fluid installations (mainly water and water vapor), a boiler or steam generator, a flow part of a turbine equipped with regenerative steam extraction that drives, for example, an electric generator, and which is then connected either to an intermediate superheater, then with the following, at least one working cylinder of the turbine and then with a condenser, or directly with an exhaust steam condenser, the cavity of which is cooled by an external coolant is connected via a pump to at least one regenerative low-pressure heater, which is then connected, if necessary, to a deaerator and then with the heated side of at least one surface regenerative high-pressure heater, which is further connected to the input of the working fluid into the boiler or steam generator, while It is also equipped with cogeneration steam extraction, made with the possibility of providing the consumer with thermal energy.

 At the same time, the following two main disadvantages are inherent in the known method for operating a steam-powered power plant and a plant for its implementation.

 The first of them is that in the operation mode of a power plant with a nominal (or close in magnitude) electric power productivity due to the operation of the main flow of the working fluid (steam) and a turbine equipped to increase the electrical efficiency of the installation with regenerative high-pressure and low-pressure steam , the maximum power and temperature potential of thermal energy supplied by the installation to an external consumer are limited by the limits of thermodynamic capabilities of heat extraction from a turbine (type Fr, T, R, RT and / or TK) remaining steam flow, which provide the above heat demand.

 The second disadvantage of the known method of operating a steam-powered power plant is the rather stringent dependence of the value on the heat load required by the consumer, on the value of the electric load of the consumer of electricity. The indicated dependence is especially noticeable and adversely affects the production and economic performance of the power plant during its operation with a given reduced electrical load of the consumer, for example, in the winter, heating season or during planned and other breaks in industrial work, etc. electricity consumers, when, regardless of the specified reduction in electrical load, it is especially necessary to increase or at least maintain at a level close to the nominal power of thermal energy supplied to the consumer, for example, for heat supply. This drawback is determined by the fact that in a known steam-powered power plant during this period, respectively, an electric load set by one consumer reduces the consumption of the working fluid coming from the boiler or steam generator to the turbine rotating the electric generator, and accordingly it is desirable to reduce the cost of heat-insulating steam extraction from turbines used in similar power plants such as PT, T, K, CT and / or TK, which provide another consumer with thermal energy. That is, in the periods of decrease in the electric load (power of the electric generator of the power plant) that exist in practice, for example, to ~ 60% of the nominal maximum power of the heat energy supplied to the consumer will also decrease to ~ 60% of the nominal, which ultimately significantly affects production and economic interests of the producer and consumers of thermal energy.

The foregoing shortcomings of the known method of operating a steam-powered power plant and a plant for its implementation is an objective reality and therefore, with the often identified need to build additional heat consumers in residential areas, buildings, enterprises, etc. in the area adjacent to the existing TPP (based on the above-mentioned known power plants) p., as well as to cover the shortage of thermal energy issued by the power plant during periods of a decrease in its energy load, it is generally accepted in practice (see, for example , the book "Steam Turbines", A.V. Shcheglyaev, M., Energoatomizdat, 1993, book 2: p. 262, 265) that in the area of operation of the said CHP (or CHP) should be built, at least an additional boiler room, which, to cover the first heat deficit described above, should work mainly in the basic operation mode, and to cover the second heat deficit indicated above, it should work mainly in peak or semi-peak operation modes. Naturally, the construction and operation of an additional boiler house (and even more so a thermal power plant) is quite expensive, and it should also be borne in mind that, unlike the most economical one, the above combined generation of electric and thermal energy by a power plant for consumers, the need to build an additional separate boiler room ( on any type of fuel) due to the relatively low value of its efficiency (~ 0.86-0.90) it will require a corresponding increased (1 / 0.86 ... 0.90 times) fuel consumption, the high temperature potential of which Besides badly used by burning it to produce a low temperature (~ 150-250 ^o C) coolant heat consumer serving. Moreover, the greater the power value of the indicated additional boiler house, the less economical will be the overall energy system, consisting of the well-known steam power plant and this boiler house, since in this case the proportion of thermal energy produced in addition to electricity production is reduced.

 In connection with the stated main technical problem, the claimed inventions are directed to (the method of operation and the device for its implementation) are aimed at increasing the efficiency of a steam-powered power plant with combined generation of electricity and heat, as well as reducing the dependence of its heat load on the consumer's electrical load by economical increase in the maximum power of thermal energy issued to the consumer during its operation at any operating level e electrical consumer load, i.e. at low power setting and a maximum power generator, generating a predetermined electric power by the consumer. Moreover, the solution of this problem also increases the average temperature potential of the heat removed in the thermodynamic cycle of the installation to the consumer, without changing the nomenclature and number of basic units (elements) of the equipment of the known combined steam-powered power plant, which ultimately eliminates or significantly reduces the capital and operating costs of creating and operation usually in practice of the existing additional well-known boiler house (or CHP) covering the deficit required above issued aforementioned increase heat energy to the consumer or required to enable the construction in the area of additional objects CHP - heat consumers, or to provide at least a nominal (or close thereto value) outputted heat performance during periods of substantial reduction of electrical load another user.

 To solve the stated problem in a known method of operating a steam-powered power plant, in which a compressed, for example, the liquid phase of the plant’s working fluid, mainly water, is sent to a boiler or steam generator, where at constant pressure due to the heat of the fuel it is heated until the required parameters are formed, which then fed into the flow part of a steam turbine equipped with regenerative selections, in which the process of expansion takes place, and as a result the turbine drives, for example, an electric generator , then the steam spent in the turbine is either sent to an intermediate superheater, after which it is fed to perform work, for example, to the next at least one working cylinder of the turbine and then to the condenser, or immediately sent to the condenser, where the steam is cooled by an external heat carrier turns into the liquid phase of the working fluid, which is then pumped into at least one regenerative low-pressure heater, then fed, if necessary, to a deaerator, then sent to the heated side, at least m Herein, one surface regenerative high-pressure heater and then again sent to the boiler or steam generator of the installation, in which during its operation with the delivery of heat to the consumer, a part of the flow of the working fluid is additionally taken from the turbine, which is used to transfer thermal energy to the consumer during operation installations in the mode with increased, for each value of steam production, delivery of thermal energy to the consumer, the working fluid of the installation is directed to bypass the heated Orons of at least one regenerative high-pressure heater, the heated side of the specified heater or heaters is switched to the composition of the circulation heat exchange circuit of the consumer of thermal energy and, accordingly, the changed range of enthalpies (and, correspondingly, temperatures) of the working fluid heated in the boiler or steam generator, or increase power of the boiler or steam generator at its given, including nominal, steam production, or at the same time increase the capacity boiler or steam generator and change its steam output.

 In addition, to control the power of thermal energy supplied to the consumer through high pressure regenerative heaters, the flow rate of steam taken from the turbine to the heating sides of these heaters can be changed, while the heating side of at least one of these regenerative heaters can be switched to controlled selection of higher pressure steam.

 To achieve the above technical result, a steam-powered power plant operated according to the aforementioned claimed method is proposed, the prototype of which is selected from a wide range of known steam-powered power plants based on turbines of types K, CT, TK, T and / or PT and closest to the essence of the claimed technical solution, steam-powered power plant based on the most common and technologically advanced type K turbine (K-800-23.5-5) and which is presented in the book "Steam Turbines", A. .Scheglyaev (M. Energoatomisdat, 1993, Book 1) on page 56 and Figure 1.26. Moreover, in a steam-powered power plant containing, for example, a boiler or a steam generator combined by pipelines circulating the working fluid of the installation, the flow part is equipped with regenerative high-pressure and low-pressure steam turbines that drive, for example, an electric generator and which is then connected either to an intermediate superheater, then with the next at least one working cylinder of the turbine and then with a condenser, or directly with an exhaust steam condenser, cooled externally m the coolant side of which is connected through a pump to at least one regenerative low-pressure heater, which is further connected, if necessary, to a diaaerator and then to the heated side of at least one surface regenerative high-pressure heater of the working fluid, which is then connected with the entrance of the working fluid into the boiler or steam generator, while the turbine is also equipped with intermediate heat recovery steam, made with the possibility of providing the consumer with heat energy, the heated side of at least one regenerative high-pressure heater at the inlet and outlet of the working fluid is connected via shut-off devices to the circulation heat exchange circuit of the consumer of thermal energy, pipelines connecting the inputs and outputs of the working fluid from the heated side of the specified heater or heaters with their units of equipment adjacent to the main path of the circulation of the working fluid are equipped with locking devices, and the indicated units of equipment Fitting further interconnected encircling disposed therebetween regenerative heater or heaters, as well as locking devices corresponding bypass line, which is provided with a locking device. In this case, preferably, each pipeline providing regenerative extraction of steam from the turbine to the heating side of the high pressure heater, configured to provide the consumer with thermal energy, can be equipped with a shut-off and control device, and the heating side of at least one of the specified regenerative high heater pressure can be additionally connected through a locking and regulating device with the selection of higher pressure steam from the turbine.

The essence of the invention is illustrated by drawings, which depict:
in FIG. 1 is a schematic thermal diagram of a steam-powered power plant according to embodiment 1;
figure 2 - T-gS diagram of the ideal cycle of option 1 of the power plant during its operation with a nominal or reduced delivery of thermal energy to the consumer at nominal (as well as reduced) electric power productivity;
figure 3 is a T-gS diagram of the ideal cycle of operation of option 1 of the power plant during its operation with increased delivery of thermal energy to the consumer at nominal (as well as reduced) electric power productivity;
figure 4 is a schematic thermal diagram of a steam-powered power plant according to embodiment 2;
figure 5 is a T-gS diagram of the ideal cycle of operation of option 2 of the power plant during its operation with the maximum (for a given steam capacity or flow rate of the working fluid through the turbine) heat supply to the consumer using all three high pressure regenerative heaters;
figure 6 is a schematic thermal diagram of a steam-powered power plant according to embodiment 3;
Fig. 7 is a T-gS diagram of the ideal cycle of operation of embodiment 3 of a power plant during its operation with maximum (at a given steam output) generation of thermal energy to a consumer by means of, for example, only one high pressure regenerative heater.

 Examples of the implementation of the proposed method and device are given when using the most common substance, water, as its working fluid in a steam power plant, although the above method and device are also valid when other known substances, such as carbon dioxide, etc., are used as the working fluid of a power plant . (see, for example, the book "Power Equipment of NPP Units", N. M. Kuznetsov et al., L., Mechanical Engineering, 1979, pp. 71-74); Journal of Thermophysics of High Temperatures, ed. "Science", 1968, volume 6, issue 4, pp. 621-633 and the book "Non-water pairs in power engineering", A.A. Kanaev and I.Z.Kopp, L., Mechanical Engineering, 1973, pp. 29-33, 74, 90).

 The proposed method of operating a steam-powered power plant producing electric and thermal energy is carried out in the following sequence.

 During operation of the installation in a mode with increased thermal energy for each steam output for the consumer, the working fluid of the installation is sent to bypass the heated side of at least one regenerative high-pressure heater, the heated side of the specified heater or heaters is switched into a circulation heat exchange circuit heat energy consumer and at the same time, according to the changed range of enthalpies heated in the boiler or steam generator which body or increase the power of the boiler or the steam generator at a given, including face, its steam output, or both increase the power of the boiler or steam generator and alter its steam output. In addition, to control the power of thermal energy supplied to the consumer through high pressure regenerative heaters, the flow rate of steam taken from the turbine to the heating sides of these heaters can be changed, while the heating side of at least one of these regenerative heaters can be switched to controlled selection of higher pressure steam.

 Option 1 of the proposed steam-powered power plant consists of the following basic units of equipment, combined by the corresponding pipelines and / or cavities of the hull structures.

 The output of the installation’s working fluid is a pair of set parameters from the boiler (including, for example, a waste-heat boiler of a combined cycle gas turbine power plant) or steam generator 1 is connected to the flowing part of a high pressure working cylinder 2 of a steam turbine 3, the output of which is connected to an intermediate superheater 4 of boiler 1, which, like boiler 1, works due to the heat of organic or, for example, nuclear fuel (not shown in the diagram). The steam outlet from the superheater 4 is connected by a pipeline to the steam inlet to the flowing part of the medium pressure working cylinder 5 of the turbine, the main steam flow output from which is connected to its entrance to the low pressure working cylinder 6 of the turbine 3. All working cylinders 2, 5 and 6 of the turbine 3 are installed on one shaft, with which, for example, through a gearbox (which is not shown in the drawing), the turbine can rotate an electric generator 7, intended for the production of electrical energy to consumers. The outlet of the exhaust steam turbine 3 is connected to the cooled side (cavity) of the condenser 8, equipped with a pipe heat exchange system 9, through which an external cooling coolant circulates, mainly water, for example, from the cooling tower of the thermal power station, which the hell. not shown. The condensate outlet of the working fluid from the condenser 8 through the condensate pump 10 is connected to the entrance to the heated side of the regenerative surface low pressure heater 11, which is further connected to similar heated sides of the regenerative low pressure heaters 12 and 13. The condensate outlet of the working fluid (feed water) from the heater 13 connected to a mixing type deaerator 14, which serves for the thermal removal from the feed water of gases dissolved in it, mainly oxygen and carbon dioxide . It should be noted that studies and laboratory studies suggest that for promising power units of nuclear power plants and thermal power plants, regenerative heating water systems have certain capabilities, in which the deaerator is replaced by a surface regenerative heater or, as one of the possible options for a deaerationless regenerative heating circuit, scheme with mixing regenerative low-pressure heater (see, for example, the article "Deaeration-free scheme of regeneration of high-power steam turbines ", G.I. Efimochkin et al. in the journal" Heat Power Engineering ", 1977, N5, pp. 27-30 and the book" Power Equipment of Nuclear Power Plant Units ", N. M. Kuznetsov and others. , L., Mechanical Engineering, 1979, p. 220).

 The outlet of the feed water from the deaerator tank 14 is connected to the feed pump 15, which serves to further compress the water to a predetermined pressure and then supply it along the main circuit of the installation. It can be noted that in addition to the electric drive, for a more economical change in the flow of feed water, the pumps 15 and 10 can also be equipped with turbo drives based, for example, on the turbines R-11-1.5 / 0.3, K-17-1.5 P and K-12-1, OPA (see, for example, the book "Steam Turbines", A.V. Shcheglyaev, M., Energoatomizdat, 1993, book 2, pp. 386-398), working at the expense of adjustable flow rate of steam taken from the turbine 3 (not shown in the drawing).

 The water outlet from the feed pump 15 through the control device 16 and then through the shut-off device 17 is connected to the heated side of the surface regenerative high-pressure heater 18, which is further connected to a similar regenerative heater 19, which, in turn, is also connected to the regenerative heater 20 , the outlet of feed water from the heated side of the last regenerative heater 20 through a shut-off device (for example, a valve or gate valve) 21 is connected to the water inlet th boiler or steam generator 1, and thus the main circular working fluid circulation loop installation closed. The feed water inlet to the heated side of the first regenerative high-pressure heater 18 and the water outlet from the heated side of the last, in this case, third high-pressure heater 20 are connected via shut-off devices 22 and 23, respectively, to the heat exchange consumer circuit 24, which includes in particular, a circulator made in the form of a water pump 25 (other elements of this circuit 24 are not shown). In relation to the heaters connected to the consumer in this case, heaters 18-20 units of the equipment of the main feedwater path of the installation — the control device 16 and the boiler or steam generator 1 are additionally interconnected bypassing the heaters and shut-off devices 17, 21 located between them, bypass piping 26, which is also equipped with a locking device 27. It should be noted that, unlike the foregoing, according to the claimed invention, it is possible, if necessary, to use to increase the supply of thermal energy to the consumer, not using all regenerative high-pressure heaters, as provided in FIG. 1, and to a lesser extent - using, for example, one or two of them (see option 6 of embodiment 3 of the proposed installation and figure 7 below).

 The outputs of the regenerative steam extraction from the intermediate stages of the working cylinders 2 and 5 of the turbine 3 are connected respectively to the steam inlets to the heating sides (annular spaces) of the high pressure regenerative heaters 20, 19 and 18 using pipelines 28, 29 and 30, each of which is respectively equipped with a shut-off -regulating device 31, 32 and 33. For consecutive flows of condensates of the selected heating steam into the deaerator 14, the annular spaces of the heaters 18-20 are interconnected, while the annulus is simple the heater 18 is finally connected to the cavity of the deaerator 14, in which the pressure is always less. To ensure the heating and boiling of feed water in the deaerator 14, its upper cavity is connected by a pipe 34 to the output of the heating steam taken from the intermediate stage of the working cylinder 5 of the turbine 3. In addition, the specified pipe 34 is connected via a pipe 35 provided with a shut-off and control device 36 with steam entering the heating side (annular space) of the network water heater 37 of the thermal energy consumer. Next, the output of the lower pressure steam extraction from the intermediate stage of the working cylinder 5 of the turbine 3 and the steam inlet to the heating side (annular space) of the low pressure regenerative heater 13 are interconnected by a pipe 38. In this case, the pipe 38 is additionally connected by a pipe 39 equipped with a shut-off and control device 40 , with steam entering the heating side of the network water heater 41. Similarly, the output of heating steam of even lower pressure from the intermediate stage of the working cylinder 5 of the turbine 3 and the steam inlet to the heating the south side of the regenerative heater 12 is connected by a pipe 42, which, in addition, is connected by a pipe 43, equipped with a shut-off and control device 44, with steam entering the heating side of the network water heater 45. The last output of the heating steam taken from the low pressure working cylinder 6 of the turbine 3 and steam inlet to the heating side of the regenerative low-pressure heater 11 is connected by a pipe 46. For consecutive flows of the generated condensates of the heating steam into the condenser 8, the annular spaces are heated evateley 11-13 are connected together and, finally, the total yield of the condensate of the heating steam heater 11 connected through a duct 47 with the cavity of the capacitor 8, wherein the pressure medium is smallest. The heated sides (for example, pipe systems) of surface network water heaters 37, 41 and 45 are interconnected and, in addition, are an integral part (heat source) of the consumer circulation heat exchange circuit 48, through which the network heat carrier, for example water, is circulated by the pump 49 For consecutive overflows of heating steam condensate from the heater 37 through the heater 41 to the heater 45, the annular spaces of the heaters 37, 41 and 45 are interconnected, while the output of the total heating condensate a pair of mains water heater 45 is connected with the cavity of the lowest pressure in the circuit - 8 condenser conduit 50. If necessary, the above circulating heat exchange circuits 24 and heat consumer 48 may be connected (not shown in Fig.).

 The characteristic points of change in the physical state of the working fluid of the above-described steam-powered power plant (inputs and outputs of the working fluid from the main elements of the plant equipment) are marked in FIG. 1 letters "b, c, d, ... n,". The same letters indicate the corresponding characteristic points of the thermodynamic T-gS diagrams (see Fig. 2, 3) of ideal cycles of operation of the above presented embodiment 1 of the proposed power plant in two main modes of its operation.

In FIG. Figure 2 shows the T-gS diagram of the ideal cycle (with intermediate superheating of the steam and its subcritical initial pressure) of operation of option 1 of the power plant during its operation with nominal or reduced heat energy output to the consumer at rated (as well as reduced) power installation performance. In connection with the use of steam taken from a turbine in a regenerative heating water cycle, a feature of this diagram is the deposition of reduced entropy along the abscissa axis (see, for example, the book "Fundamentals of Thermodynamics of Cycles of Thermal Power Plants", A.I. Andryushchenko, M., High School, 1977, pp. 69-71). Each selection of steam from the turbine 3 is shown in the diagram with the corresponding horizontal section of the broken line b-s (sections b, c, d, e, f, f). Its vertical sections are the processes of steam flow remaining in the turbine. The process of expansion of steam in the turbine goes along the line p-b-s. In addition, in the diagram of FIG. 2 the following designations are indicated:
q ₁ - specific heat supplied to the working fluid of the cycle in the boiler or steam generator 1;
Q _p1 - heat of regeneration transferred to feed water by regenerative heaters 11-13, 18-20 and deaerator 14 inside the cycle (the direction of heat transfer is indicated by an arrow);
Q _to - the heat given off by the working fluid to the external environment in the capacitor 8;
Q _t1 - heat supplied to the consumer through the network water heaters 37, 41 and 45.

In FIG. Figure 3 shows the thermodynamic T-gs diagram of the ideal cycle of operation of option 1 of the power plant during its operation with increased output of thermal energy to the consumer at nominal (as well as reduced) electric power productivity. Moreover, in contrast to the diagram in FIG. 2, the following notation is indicated in this diagram:
Q ₁ - summed up in the cycle (boiler or steam generator 1) (specific) heat;
Q _p2 - heat of regeneration transferred to feed water by regenerative low-pressure heaters 11-13 and deaerator 14 inside the cycle (heat transfer direction is shown by an arrow);
Q _t2 - additional heat generated with a higher temperature potential to the consumer through regenerative high-pressure heaters 18-20;
k is a point in the diagram characterizing the physical state of the working fluid of the power plant in this operating mode before it enters the boiler or steam generator 1.

Depicted in FIG. 4 option 2 execution of a steam-powered power plant, implemented according to the claimed invention, in contrast to that depicted in FIG. 1 options 1 execution, arranged as follows:
the pipeline 28 (after the "exit" of the selected steam from the shut-off and regulating device 31) is connected by a pipe 51 with a selection of "a" from the cylinder 2 of the turbine 3 of a higher pressure steam than in the selection of "b"; while the pipeline 51 is equipped with a locking and regulating device 52;
the pipeline 29 (after the "exit" of the sampled steam from the shut-off and control device 32) is connected by the pipe 53 with the selection "b" from the cylinder 2 of the turbine 3 steam of higher pressure than in the selection "c"; while the pipeline 53 is equipped with a locking and regulating device 54;
the pipeline 30 (after the "exit" of the selected steam from the shut-off and control device 33) is connected by the pipeline 55 with a selection "in" from the cylinder 5 of the turbine 3 steam of higher pressure than in the selection "g"; while the pipeline 55 is equipped with a locking and regulating device 56.

 The remaining symbols shown in FIG. 4 are the same as in FIG. 1.

In FIG. Figure 5 shows the thermodynamic T-gS diagram of the ideal cycle of operation of option 2 of the power plant during its operation with the maximum (at a given value of the flow of the working fluid through turbine 3) heat supply to the consumer using all three 18-20 regenerative high-pressure heaters. Moreover, in contrast to FIG. 3, the following notation is indicated on this diagram:
Q ' ₁ - specific heat (kJ / kg) suppressed in the cycle (boiler or steam generator 1);
Q ' _p2 is the heat of regeneration transferred to the feed water by regenerative low-pressure heaters 11-13 and deaerator 14 inside the cycle (the direction of heat transfer is indicated by an arrow);
Q ' _to - the heat given off by the working fluid to the external environment in the capacitor 8;
Q ' _t1 - heat supplied to the consumer through the network water heaters 37, 41 and 45;
Q ' _t2 - additional heat generated with a higher temperature potential to the consumer through regenerative heaters of high pressure 18-20;
a is a point in the diagram characterizing the physical state of the working fluid in the turbine 3 of the power plant during regenerative selection of the highest vapor in the pressure cycle.

 Depicted in FIG. 6, embodiment 3 of the steam-powered power plant implemented according to the claimed invention is arranged, in contrast to the one depicted in FIG. 4 options 2 execution, as follows. The input of the working fluid to the heated side of the regenerative high-pressure heater 20 is connected via a shut-off device 57 to the circulation circuit 24 of the heat energy consumer, and the pipeline connecting the input of the working fluid to the heated side of the regenerative heater 20 with a unit of equipment that is adjacent to the (previous) main circuit of the working fluid circulation installation - regenerative heater 19, is equipped with a locking device 58. In this case, the input and output of the working fluid from neighboring in relation to the regenerative heater 20 units of equipment of the installation - respectively, the boiler or steam generator 1 and the regenerative high-pressure heater 19 - are interconnected bypassing the regenerative heater 20 located between them and the shut-off devices 58 and 21, the corresponding bypass pipe 59, which is equipped with a shut-off device 60.

In FIG. 7 shows a thermodynamic T-gS diagram of the ideal cycle of operation of option 3 of the power plant during its operation with the maximum (for a given value of the flow of the working fluid through the turbine 3) heat energy to the consumer using, for example, only one high pressure regenerative heater 20. , in contrast to FIG. 5, the following notation is indicated on this diagram: Q '' ₁ - summed in the cycle (boiler or steam generator 1)) heat;
Q _p3 - heat of regeneration transferred to feed water by regenerative heaters 11-13, 18, 19 and deaerator 14 inside the cycle (the direction of heat transfer is indicated by an arrow);
Q '' _k is the heat given off by the working fluid to the external medium in the condenser 8;
Q '' _t1 - heat supplied to the consumer through network water heaters 37, 41 and 45;
Q '' _t2 - additional heat generated with a higher temperature potential to the consumer through the regenerative high-pressure heater 20;
p is the point of the diagram characterizing in this operating mode the physical state of the working fluid of the power plant when exiting the regenerative heater 19, that is, before it enters the boiler or steam generator 1.

 Three of the above options for the implementation of steam-powered power plant (EU), operating according to the proposed method of operation, operate in the following main operating modes as follows.

Option 1
The operating mode of option 1 EA with nominal or reduced heat energy to the consumer
During this operating mode of the EU (for example, during reduced heat loads of the heating season, during the non-heating season, etc.), the position of the valves on the circulation paths of the installation’s working fluid is as follows (see Fig. 1): the control device 16 is open to the extent , which provides a given flow rate of feed water; locking devices 17, 21 are open, locking devices 22, 23 and 27 are closed, locking and regulating devices 31, 32 and 33 are fully open, and locking and regulating devices 36, 40 and 44 are fully or partially open, and can also be (when disconnecting the heat load) temporarily closed.

During operation of the power plant in this mode, a compressed, for example, the liquid phase of the plant’s working fluid, mainly water, is sent to a boiler or steam generator 1, where it is heated at a constant increased pressure due to heat of fuel (see summed heat Q ₁ in FIG. . 2) until the steam is formed the parameters necessary for working in the turbine, for example, for the selected prototype: power plants with a K-800-23.5-5 turbine - up to a temperature of 540 ^o C at a pressure of ≥240 atm. The resulting steam is then sent to the flowing part of the working cylinder 2 of the turbine 3, in which the process of expansion takes place, as a result of which the turbine drives an electric generator 7. The 2 steam spent in the high-pressure cylinder (for example, with a pressure of ~ 37 atm) is sent to an intermediate superheater 4, after heating in which (for example, to a temperature of 540 ^o C) steam is supplied to carry out work in the following working cylinders of medium and low pressure 5 and 6 of the turbine 3. The main steam flow out of the turbine 3 is then sent to the condenser ator 8, in which under reduced pressure (~ 0.04 ata) due to cooling by an external heat carrier (see, for example, the heat transferred Q _to in Fig. 2) circulating in the pipe system 9, it turns into the liquid phase of the working fluid, for example feed water. The feed water emerging from the condenser 8 is supplied by a condensate pump 10 as a heated medium to at least one regenerative low-pressure heater, in this case there are three of them - 11, 12 and 13. In these regenerative heaters, the feed water is heated, for example, to 120 -140 ^o C) by the heat of condensation of the vapor withdrawn from the intermediate stages of the turbine 3, respectively, via conduits 46, 42 and 38. due to the pressure difference generated in the heating steam condensates preheaters in series flow from mezhtr of the entire space of the heater 13 to the heater 12, then to the heater 11 and, as a result, through the pipe 47 they enter the cavity of the lowest pressure of the circuit - the condenser 8. From the heated side of the last regenerative low-pressure heater 13, the feed water flows to remove the dissolved gases from it into the column deaerator 14 where it is heated (to a temperature of 140-168 ^o C) and boils (at a pressure of about 3-7 atm) due to the heat of condensation of heating steam supplied to the deaerator 14 through conduit 34 from an intermediate stage workers a medium-pressure turbine 5 of the cylinder 3 (steam extraction "d"). Further, from the deaerator tank 14, the feed water is drawn, for example, by the feed pump 15, is compressed to a predetermined pressure, and then through the open regulating device (water flow rate or steam capacity controller) 16 and the shut-off device 17 is directed to the heated side of at least one, and in this case - sequentially, on the heated sides of all three high pressure regenerative heaters 18, 19 and 20. Moreover, on the heating sides (for example, annular spaces) of said regenerative heaters 18-20 respectively, through pipelines 30, 29 and 28 from the intermediate stages of the working cylinders 5 and 2 of the turbine 3 (the steam withdrawals “g”, “c” and “b” are supplied with a part of the steam flow rate operating in the turbine 3. As a result, the feed water is heated at the outlet of the last regenerative heater 20 to a temperature that is slightly lower (by ≤10 ^o C) the temperature of steam saturation at a pressure coming from the selection "b" of steam. For modern steam-powered power plants operating on water vapor, optimal (to obtain maximum electrical efficiency of EI) t the temperature of regeneratively heated feed water is 0.65-0.75 of the saturation temperature of water vapor at the initial pressure of the water entering the boiler or steam generator, and at supercritical parameters of fresh steam, in particular for the common fresh steam pressure of 240 atm (as in the selected prototype of the proposed EA), the temperature of regeneratively heated feed water is chosen equal to 265 or 274 ^o C (see, for example, the book "Steam turbines", A.V. Scheglyaev, M., Energoatomizdat, 1993, Prince 1, p. 53). For the selected numerical example, a complete regenerative heating of feed water is carried out up to 274 ^o C - that means from the selection "b" to the heating side of the last regenerative heater 20 steam comes in with a pressure of ~ 68-70 at. As a result, regeneratively heated feed water is then fed through an open shut-off device 21 (see point "l" in the diagram of Fig. 2) to a boiler or steam generator 1 for subsequent heating and supply along the operating circuit of the EU.

In addition to the above-described process of generating electricity, this embodiment of the power plant provides controlled delivery of thermal energy to the consumer using network water heaters 37, 41 and 45. In this case, the heating sides of these heaters, respectively, come through pipelines 35, 39 and 43 with different steam pressures, taken from the intermediate stages of the working cylinders 5 and 6 of the turbine 3 (steam selection "d", "e" and "g"). As a result of heat exchange, the condensates of the heating steam subsequently flow from all the heaters 37, 41 and 45 through the pipeline 50 into the cavity of the lowest pressure of the circuit - into the condenser 8, from where they are taken with the rest of the water by the condensate pump 10 for feeding into the circuit. The network water of the consumer circuit 48 is pumped by the pump 49 in a countercurrent circuit with heating steam sequentially through the heated sides of the network heaters 45, 41 and 37, as a result of which it is heated to a working temperature of 130-150 ^o C.

The power control of the electric generator 7 of the power plant is carried out mainly due to changes in the regulating device 16 of the flow of the working fluid pumped by pumps 10 and 15 along the main circuit. It is also known (see, for example, the book "Steam Turbines", A. V. Scheglyaev, M., Energoatomizdat, 1993, book 2, p. 160) that the change in the flow rate of fresh steam passing through the turbine 3 , can be provided taking into account the corresponding changes in the thermal power of the boiler or steam generator 1 in the following fundamentally different ways:
at constant steam parameters (pressure and temperature, in front of the turbine stop valves and corresponding opening (cover) of the turbine control valves;
a change in steam pressure in front of the turbine shut-off valves while the control valves are always open (regulation is carried out using a boiler at TPPs and TPPs, a steam generator at dual-circuit nuclear power plants and a reactor at single-circuit nuclear power plants);
a change in temperature and pressure of fresh steam (regulation depends on the operating mode of a gas turbine installation of combined cycle gas power plants).

In this case, the regulation of the heat power supplied to the consumer in the network circuit 48 through the heaters 37, 41 and 45 is carried out by a corresponding change in the degree of opening of the shut-off and control devices 36, 40 and 41, through which the heating steam taken from the turbine 3 (its maximum flow rate and parameters determined mainly by the corresponding parameters of the main stream of steam passing through the turbine 3) enters the network heaters. If necessary, the heat load of the consumer can be completely turned off (Q _t1 = 0 and Q _p1 = max in Fig. 2) by closing all shut-off and regulating devices 36, 40, and 44, and then the turbine 3 of the power plant will operate in pure condensation mode with the possibility of issuing the generator 7 maximum electric power.

 Thus, for the selected numerical example, this power plant will provide (the same as that of the selected prototype) the rated power of the electric generator is 7 - 850 mW (el.) And the nominal thermal load of the consumer - up to 163 mW (warm). The fuel heat utilization coefficient characterizing the economics of a power plant will be 0.483.

The operating mode of option 1 EA with increased for each value of steam output of thermal energy to the consumer
This mode (see Fig. 1.3) operation of a steam-powered power plant (for example, during the heating season, etc.) reflects the essence of the claimed technical solution. The differences between the operation of the EU in this mode from the above are as follows.

 The locking and regulating devices 17 and 21 are switched to the closed position, and the locking devices 22, 23 and 27 to the open position.

As a result, water leaving the deaerator 14 and compressed by the feed pump 15 to a predetermined pressure (for example, up to 240 atm) is pumped through an open control device 16 to bypass the heated sides of all three (it is also allowed to bypass, for example, one or two) regenerative heaters of high pressure 18, 19 and 20 through the bypass pipe 26 through the open locking device 27 into the boiler or steam generator 1 for subsequent heating. Moreover, due to the shutdown in this operating mode of the charger from heating feed water of regenerative high-pressure heaters 18-20 for each value of the given steam capacity (D, kg / s), the water entering the boiler or steam generator 1 will have a lower temperature compared to the above-described operation option 1 execution EU. Therefore, the temperature range and, correspondingly, the enthalpies (Δi, kJ / kg) of the working fluid heated in the boiler or steam generator 1 will generally change and, in particular, while preserving the initial parameters, the steam will increase (for example, for the selected numerical example at water pressure in deaerator 7 ata - the temperature range of the heated working fluid will increase by ≥ 110 ^o C). In this regard, as well as with the existing various designs and operation models of combined EIs, corresponding to the temperature range and enthalpies of the working fluid heated in the boiler or steam generator, which have changed in this mode, various economical options for ensuring the heat balance between the thermal power of the boiler or steam generator 1 (N _k , MW) and the working fluid heated by it with the given parameters. In general, the specified heat balance is determined by the following relation: N _k = D • Δ i, where N _k is the thermal power of the boiler or steam generator, D is the steam capacity of the boiler or steam generator, and Δi is the difference in the enthalpies of the working fluid at the inlet and outlet of the boiler or steam generator.

The above ratio determines, in contrast to the above operation mode of the proposed installation, the following main options for ensuring thermal balance during the implementation of the inventive method of operation of a combined steam-powered power plant in this considered period of its operation with increased, for each value of steam production, thermal energy output to the consumer:
A) in order to maintain the maximum amount of electricity produced at a given (including nominal) steam capacity (D), the pair of rated parameters in the boiler or steam generator, the thermal power of the boiler or steam generator (N _k ) is increased in proportion to the increase in the difference in the enthalpies of the heated working fluid (Δi) ;
at the same time, during the operation of the electric power plant with an increased thermal load and a simultaneous decrease in its electric load, the thermal power of the boiler or steam generator (N _k ) is reduced simultaneously with a corresponding decrease in its steam capacity (D);
B) with limited, for any reason, possibilities of increasing the thermal power of the boiler or steam generator EI, necessary to ensure (as in option A) the nominal steam parameters in accordance with the increased difference in the enthalpies of the heated working fluid (Δi), in order to ensure the maximum increasing the electric and thermal loads of the installation, at the same time increasing the thermal power of the boiler or steam generator (N _k ) and lowering its steam capacity (D);
C) during operation of the proposed electric power plant in, for example, a double-circuit, water-water atomic heat and power plant (ATEC), in order to ensure the maximum increase in the electric and thermal loads of the installation, they simultaneously increase the heat output of the boiler or steam generator (N _k ) and increase the steam productivity of steam ( D) reduced parameters (i.e., with a smaller Δi).
Moreover, for option A, to ensure the thermal balance between the capacity of the boiler or steam generator and the heated working fluid of the proposed power plant, the thermal power of the boiler or steam generator 1 is increased according to the expanded range of enthalpies of the water heated in the boiler (in the numerical example - by ~ 17%) and, as a result, into the turbine 3 acts the same as in the previous operating mode of option 1 of the EA, steam consumption with the same initial parameters. The costs and parameters taken from the turbine 3 to all of the above regenerative low pressure heaters 11-13 and high pressure 18-20, as well as to the network heaters 37, 41 and 45 remained the same. Therefore, the power of the electric generator 7, driven by the turbine 3, will be proportional to the steam capacity and, in particular, will be nominal at the nominal steam capacity of the installation.

In addition, in the proposed EA, in order to increase the total heat energy output to the consumer, in addition to the network heaters 37, 41 and 45, the heated sides of the regenerative high-pressure heaters 18-20 are connected to the heat transfer to the consumer, the heating sides of which continue to be obtained from b "," in "and" g "turbines 3 heating steam, which was previously used for regenerative heating of feed water. In this case, the pump 25 of the circulating heat exchange circuit 24 of the heat energy consumer through the heated sides of the regenerative heaters 18, 19 and 20 disconnected at that time from the feed water, pump the network coolant, mainly water, which can be heated due to the heat taken from the turbine 3 steam to a temperature (230-270 ^o C) 1.5-2.3 times greater (see Fig. 2,3) than the maximum temperature of the network coolant in the previously described circuit 48 of the consumer of thermal energy. To regulate the power of thermal energy supplied to the consumer through regenerative high-pressure heaters 18-20, the opening degrees of the shut-off and control devices 33, 32 and 31 installed on the pipelines 30, 29 and 28, through which the selected heating steam enters these heaters, are accordingly changed.

 Thus, with the above option A, to ensure the heat balance between the capacity of the boiler or steam generator 1 and its steam capacity for the numerical example selected on the basis of the well-known EU K-800-23,5-5, the proposed steam power plant while maintaining the ability to provide the rated power of the generator 7 - 850 MW (e.) provides during the necessary periods of operation an increase in the total capacity of thermal energy supplied to the consumer from 163 MW (t) to 370 MAt (t), that is, by 3.27 times compared with the known proto Ipomoea. At the same time, it is also possible to increase the temperature potential of the generated heat by 1.5-2.0 times, which significantly expands the technological capabilities of the consumer. The coefficient of thermal use of heat of fuel of a power plant in this mode of operation increased from 0.483 to 0.561, i.e., by ~ 16%, which indicates a significantly higher degree of efficiency of the proposed power plant compared to the known prototype.

 If it is necessary to reduce the electrical load of the proposed power plant by the consumer and at the same time ensure its maximum heat load, the thermal power of the boiler or steam generator 1 is reduced simultaneously with a corresponding decrease in its steam capacity by reducing the degree of opening of the control device 16 and the corresponding steam pressure regulator in the turbine 3 (which is not shown shown). And in this case, the value of the heat utilization coefficient of the fuel of the installation will remain at the same, rather high level. It follows from the foregoing that in the proposed power plant, due to the possibility of a significant increase in the total heat output given to the consumer at a given steam output, the necessary independence of the heat load of the consumer from the power of the electric generator generating electricity required by another consumer increases accordingly. This is important, for example, when during the heating season (or a similar one in terms of heat consumption) of the power plant operation, it is necessary to significantly reduce the power of electricity supplied to a specific consumer or to a region-wide energy system. In such a situation, for the considered numerical example, a power plant operating according to the proposed method of operation in the mode with an increased heat load can significantly reduce the power of its electric generator (and in proportion to this - the steam capacity) to (163/163 + 370) • 100 = 30.6% of nominal, providing in this case, in contrast to the prototype and other well-known steam-powered power plants, the nominal thermal energy productivity of the consumer, that is - 163 MW (heat.).

To implement the above option B, to ensure thermal balance between the capacity of the boiler or steam generator (N _k ) and its steam capacity (D) with a changed range of enthalpies (Δi) of the heated working fluid, the proposed power plant operates in the specified operating mode similar to the above.

Option B to ensure a thermal balance between the capacity of the boiler or steam generator (N _k ) and its steam capacity (D) has the following features in the case of the implementation of the proposed technical solution consisting, for example, of a double-circuit, water-water ATEC. In this case, the provision of the required by the claimed method of operation increase in the capacity of the plant’s steam generator by ~ 10-17% (when switching to a mode of operation with increased thermal energy output to the consumer) is achieved by increasing the capacity of the pressurized nuclear reactor with the feed water temperature set by the inventive method by the entrance to the steam generator, which determines the corresponding decrease in the average temperature of the 1st circuit in the reactor core. To maintain an acceptable minimum margin of power in the core until a heat transfer crisis, taking into account deviations of the installation parameters, the initial parameters of the steam (pressure and temperature) generated by the steam generator are slightly reduced (like Δi), and the steam production (D) of the steam-powered power plant is accordingly increased (by ~ 10%) due, for example, to increase the productivity of pumps 10 and 15 or to turn on additional pumps, which the hell. not shown. At the same time, the dependences of the electric and thermal power issued to consumers and their cost on the selected parameters of the second circuit can have optimal ratios. Otherwise, the proposed steam-powered power plant operates as part of the APEC in the specified operating mode, similar to the above. It should be noted that, in addition to stationary APPPs, it seems appropriate to use the proposed technical solution in floating steam turbine APPPs necessary for electric and heat supply (with a coolant temperature of up to ~ 200-300 ^o C) of the basins of the northern rivers, the coasts of the northern and Far Eastern seas, and , for example, for desalination of sea water.

 For the reverse transition of the considered option 1 of the proposed steam-powered power plant to the previous operation mode with a nominal or reduced heat output to the consumer, the locking devices 17, 21, 22, 23 and 27 are switched to the previous ("opposite") positions. As a result, regenerative high-pressure heaters 18–20 go into the mode of regenerative reheating of feed water and the heat output of the boiler or steam generator 1, respectively, decreases by ~ 10–17%. In this case, the electric efficiency of the power plant will increase slightly, and the coefficient of heat of fuel will decrease to the initial sufficiently high value. If necessary, with the specified transition of the control unit from mode to mode, the heated sides (pipe systems) of the regenerative heaters 18-20 previously used to generate heat can be periodically washed before feeding them with water (not shown).

Option 2
The operating modes of option 2 EU with reduced, nominal and increased generation of thermal energy to the consumer.

 For these operating modes, option 2 of the proposed steam-powered power plant (see Fig. 4) can provide the same production and economic indicators as the above-mentioned option 1 of the EC performance in similar operating modes (see Fig. 1, 2, 3). To ensure this, in option 2 of the actuator, the valve positions must be (in addition to the valve positions in the similar modes of variant 1 of the EA) the following: shut-off and control devices 52, 54 and 56 are closed. In connection with the periods of operation of option 2 of the proposed EA in the above modes of operation, option 2 of the EU version (see Fig. 4) is operated in the same way as the above version 1 of the EU version.

The operating mode of option 2 EA with the maximum for each value of steam output of thermal energy to the consumer
This mode of operation of a steam-powered power plant (necessary, for example, especially during the heating season, etc.) also reflects the essence of the claimed technical solution. In contrast to the above-mentioned version 1 of the EC execution, in this EC variant, the locking and regulating devices 31, 32 and 33 are switched to the "closed" position, and 55, 54 and 56 to the "open" position.

 In this case, the differences in the operation of the considered option 2 of the EC execution in this mode from the above will be as follows (see Fig. 4, 5). The heating sides of all high pressure regenerative heaters 18 - 20, the heated sides of which were switched at that time into the composition of the circulation heat exchange circuit 24 of the heat energy consumer, are switched to the selection of 3 higher pressure pairs from the intermediate stages of the turbine than in the previous operating mode of the electric power s. " .. increased thermal energy to the consumer. " In this case, steam enters the heating side of the heater 18 through the pipeline 55 through an open locking and regulating device 56 from the selection “b” (instead of the previous selection “g”), steam enters the heating side of the heater 19 through the pipe 53 through the open locking and regulating device 54 from the selection "b" (instead of the previous selection "c"), and to the heating side of the heater 20 through the pipe 51 through the open locking-regulating device 52, steam comes from the selection "a" (instead of the previous selection "b").

 As a result, in option 2 EI for any value of para-productivity and corresponding steam consumption through turbine 3, in contrast to option 1 EI in the mode with increased heat consumption, due to higher pressure values (and, correspondingly, temperatures) of the cutting steam, the power (and the available temperature potential) additional thermal energy supplied to the consumer through regenerative high-pressure heaters will increase accordingly (see. Fig. 5 and 3). The obtained advantage in providing the consumer with thermal energy is beneficial in practice, despite a slight decrease in the value of the electric efficiency of the EA, due to the fact that, on average, more than high-level steam is selected from the intermediate stages of the turbine 3 in this mode, on average. It should be noted that the fuel heat utilization coefficient in this mode of operation of option 2 of the electric power unit (taking into account the parallel heat supply to the consumer through network heaters 37, 41 and 45) will at least retain its rather high value.

 The indicated possibility of increasing the total thermal power (as well as the temperature potential) of the heat energy supplied to the consumer is especially advantageous during the period of operation of the electric power plant, when the increased thermal load of one consumer is required during a noticeable decrease in the electrical load of the other consumer (s). In this case, it is seen that the independence of the total heat load from the electric in this embodiment 2 of the EU version is higher than in the above version 1 of the EU version.

 For the numerical example presented above in option 2 of the electric power units operating according to the operating mode outlined above, the maximum power of thermal energy supplied to the consumer through regenerative high-pressure heaters 18 - 20 will increase (compared with the operating mode with increased thermal output to the consumer previously considered for variant 1 of electric power sources energy) from 370 MW to 460 MW (heat), i.e. ~ 25%. At the same time, compared with the initial total nominal capacity of thermal energy issued by the power plant to the consumer, the maximum total power of heat generated increases even more from 163 MW to 163 + 460 = 623 MW (t), that is, 3.82 times.

In this case, numerically, the amount of additional heat energy capacity (MW heat.) Issued to the consumer will be (460/850) • 100 = 54.1% of the nominal electric power of the generator; the electric load of the generator due to a decrease in the efficiency of electric power plants due to the switching of regenerative high-pressure heaters used for heat supply to offsets of a higher-pressure steam turbine will decrease to ~ 95% N _nom. , and the thermal power of the boiler or steam generator EI increases by ~ 22% of its initial power in the previous operation mode.

In the mentioned example, it was assumed that, as a result, the last steam in the flow of feed water regenerative high-pressure heater 20 receives heating steam not with a pressure of ~ 68-70 atm, but with a pressure of ~ 85-90 atm, which is quite real. The indicated increase in the maximum pressure of the heating steam entering the last of the three regenerative heater 20 to a value of 90 ata shows that the maximum temperature of the network coolant circuit 24 of the heat consumer can reach a value of 295 ^o C in the selected numerical example, which will ultimately be used for technological needs the heat consumer is not only hot water with a temperature of up to 150-200 ^o C, but also more thermodynamically effective and therefore more widely used water vapor with a pressure of up to ~ 20-40 at.

 From the FIG. 5 thermodynamic T-gS diagrams of the ideal cycle of operation of option 2 EI in the specified period of operation of the power plant with the maximum output of thermal energy to the consumer, it can be seen that the temperature potential of the thermal energy transmitted to the consumer using the “a”, “b” and “c” steam extracts and the magnitude the transferred heat Q't2 is greater than the similar indicators of options 1 and 2 of the electric power units (see Fig. 3), operated according to the proposed method without switching the heating steam take-offs from the turbine 3 to the heaters 18-20 to higher values of its pressures.

 In addition, it should be noted that for option 2 of the EU version, an intermediate version of its operation is possible, approaching the maximum heat output to the consumer, according to which not all three regenerative heaters 18-20 are switched to the selection of heating steam of higher pressure (as indicated above), but for example, only two — 19 and 20 — or one — regenerative heater 20 (not shown in the diagram of FIG. 5).

Option 3
Operating modes of option 3 EU with reduced, nominal and increased heat energy to the consumer
For these operating modes, option 3 of the proposed steam-powered power plant (see Fig. 6) can provide the same production and economic indicators as the above options 1 and 2 of EU versions in similar operating modes (see Fig. 1, 2, 3 , 4, 5). To ensure this, in option 3 EI, the valve positions should be (in addition to the valve positions in the same modes of variants 1 and 2 EU) the following: shut-off and control devices 54, 54 and 56 are closed; the locking devices 57 and 60 are closed, and the locking device 58 is open. In connection with the stated during operation periods of option 3 of the proposed EA in the above operating modes, option 3 of the EU version (see Fig. 6) is operated in the same way as the above-mentioned options 1 and 2 of EU versions.

 In addition to the above, this option 3 of the EU version, if necessary, can ensure the implementation of two additional intermediate operating modes with increased (at a given steam capacity) heat energy to the consumer, when instead of the heated sides of all three high-pressure regenerative heaters 18 - 20, the consumer’s circulation heat exchange circuit 24 only one side can be switched, for example, the last regenerative preheater high pressure pump 20. In this case, in contrast to versions 1 and 2 of the EU versions, feed water directed by the feed pump 15, passing through the flow control device 16, sequentially passes through the heated sides of two regenerative high pressure heaters 18 and 19 and then through the open shut-off the device 60 through the bypass pipe 59, bypassing the above-mentioned heater 20 and closed shut-off devices 21 and 58 located between the heater 19 and the boiler or steam generator 1, is supplied for subsequent about heating to the boiler or steam generator 1. Depending on the amount of additional heat required by the consumer, the heating steam taken from the intermediate stages of the turbine 3 can flow to the heating side of the heater 20 connected to the heat supply to the consumer from different steam take-offs: that is, or from regular "selection" b "through the pipe 28 through the open locking and regulating device 31 or from the selection of higher pressure" a "through the pipe 51 through the open locking and regulating device 52.

As a more typical example, the thermodynamic T-gS diagram of the ideal operation cycle of option 3 of the proposed EA shows exactly the last option of the two additional EA operation modes (see Fig. 7), that is, the option of its operation in the mode of maximum delivery of additional thermal energy to the consumer using only one regenerative high-pressure heater (20) when switching its heating side to the selection of higher pressure steam. Comparison of this T-gS diagram (FIG. 7) with similar diagrams of the previous EU options 1 and 2, which are shown in FIG. 3 and 5, shows: in this case, the electrical efficiency of the power plant is slightly higher, since Q '' ₁ <Q ₁ , Q '' ₁ <Q ' ₁ , Q _p3 > Q _p2 and Q _p3 >Q' _p2 , and the amount of additional the heat energy supplied to the consumer at a given steam production is less than in the cycles depicted in FIG. 3 and 5 (Q '' _t2 <Q _t2 and Q '' _t2 <Q ' _t2 . At the same time, the coefficient of heat utilization of the fuel of the proposed power plant and in this mode necessary in practice is higher than that of the known similar combined steam-powered power plants.

The operating mode of option 3 EA with the maximum for each value of steam output of thermal energy to the consumer
This mode of operation of a steam-powered power plant (necessary, for example, especially in the heating season, etc.) also reflects the essence of the claimed technical solution (see Fig. 6). For the specified operating mode, option 3 of the proposed steam-powered power plant can provide the same production and economic indicators as the above-mentioned option 2 of the EA in the same mode of operation (see Fig. 4, 5), when all regenerative ones are switched to the transfer of thermal energy to the consumer high pressure heaters.

 To ensure this, in option 3 EI, the valve positions must be (in addition to the valve positions in the same mode of option 2 EI) the following: locking devices 57 and 60 are closed, and locking device 58 is open. In connection with the stated during operation period of option 3 of the proposed EA in the above operation mode, option 3 of the EU version (see Fig. 6) is operated in the same way as the above version 2 of EU versions, and the T-gS diagrams of their ideal cycles are identical (see Fig. 5).

 As a result, it should be noted that the claimed "Method of operating a steam-powered power plant and installation for its implementation" (taking into account the required minor alterations, mainly only in the feed water path) can be used in steam-powered power plants based on widely known thermal power of steam turbine type KB КТ, ТК, Т or ПТ, which are close to the essence of the claimed technical solution. Moreover, quantitative estimates of the implementation of the proposed method in other existing power plants K-210-12,8-3 (6); L-220-4.4-5, L-310-23.5-3; TK-450 / 500-5.9; K-500-5.9 / 25: K-500-17.7; K-800-12.8-5; K-800-23.5-5 (prototype); CT-1070-5.9 / 25-3; K-1100-5.9 / 25; K-1200-23.5-3; T-180 / 210-12.8-1, T-185 / 220-12.8-2; T-250 / 300-23.5-3, PT-60 / 75-12.8 / 1.3; PT-80 / 100-12.8 / 1.3 and PT-135 / 162-12.8 / 1 (presented, for example, in the book "Steam Turbines", A. V. Scheglyaev, M., Energoatomizdat, 1993 ., book 1, pp. 70-99) showed the following generalized results that meet the technical task of the proposed solution.

a) At any (up to the nominal) power level of efficiently generated electricity, the value of the total thermal energy output given to the consumer by the power plant operated by the claimed method with the above different types of steam turbines used will increase as compared to the known combined power plants as follows:
for power plants with turbines of type K, CT or TK - 1.5-8.0 times;
for power plants with turbines of type T or PT - 1.5-2.0 times.

b) With the nominal electric power of the generator of the installation numerically, the maximum value additionally increased in accordance with the claimed method of the power of thermal energy provided by the power plant to the consumer N _t (MW heat.), will be ~ 40-60% of the nominal electric power N _nom. (MW el.) Generator of a well-known combined steam power plant, operated by a known method, that is:
N _t (MW heat.) ≥ (0.4, ... 0.60) • N _nom.el. / MW heat.

 Moreover, according to the claimed method, in the said operation mode of a power plant with increased heat energy output to a consumer, the heat output of a boiler or steam generator is increased by ~ 10-17% of its power at the same electrical load in the initial operation mode of a power plant with nominal or reduced heat output (without the proposed additional use for heat supply of regenerative high pressure heaters) of thermal energy with a lower temperature potential.

Thus, when a well-known combined steam-powered power plant is operating at a rated power of its electric generator equal to, for example, 800 MW (electric), while ensuring that the rated electric load of the electric power is maintained (see options 1, 2, 3 electric power, operated in a mode with increased output heat to the consumer and Fig. 3) the maximum increase in power issued to the consumer of thermal energy due to the implementation of the proposed method of operation
N _t ≥ (0.4, ... 0.6) • 800 MW (heat) = 320 - 480 MW (heat).

It follows from the foregoing that in order to maintain the nominal electric load of electric power during operation of the installation with increased heat output to the consumer, the proposed technical solution will eliminate the need for construction in the district of a thermal power plant, based on the well-known steam-powered combined electric power with a nominal electric power of 800 MW, an additional known boiler with a nominal power (320 - 480) / _cat efficiency _. where is the efficiency of the _cat. = 0.86-0.90 - the efficiency of known boiler plants using fossil fuels. That is, the nominal power of the additional boiler house, providing the above-mentioned increase in the heat power supplied to the consumer by the proposed power plant, will be ~ 370-555 MW (heat), i.e. numerically (in MW heat) ~ 46-70% of the nominal electric power of the generator.

c) In periods of reduced to ~ 90-95% N _nom. electric load (due to a decrease in the efficiency of electric power plants due to the switching of regenerative high-pressure heaters used for heat supply to the high-pressure steam turbines taken off), the maximum thermal load of electric power plants (see options 2, 3 of electric power plants operating in the mode with maximum heat energy output to the consumer and Fig. 5) can, at nominal steam production, numerically increase by ~ 50-75% of the lot of rated electrical power of the installation generator (while increasing the thermal power of the boiler or steam generator EI ~ 20-22% of the initial value).

 Then, as a result, in order to realize the indicated possibility of maximizing the delivery of thermal energy to the consumer, the nominal power of the additional boiler house providing the aforementioned increase in the heat power supplied to the consumer by the proposed power plant will be slightly higher numerically (in MW heat.) And will be ~ 57-85% of the nominal electric power generator.

 d) In view of the foregoing, in various well-known alternative cases of operation of a combined steam-powered power plant, namely: while ensuring the energy deficit generated during operation of the inter-regional power system or if it is necessary to maintain a high level of thermal load of electric power plants with a significant predetermined decrease in its electrical load, the proposed technical solution ( providing at almost nominal electric load the maximum heat output to the consumer) allows to exclude the usual practice (see, for example, the book "Steam Turbines", A. V. Scheglyaev, M., Energoatomizdat, 1993, book 2, p. 262, 265) construction of an additional base or peak boiler house with nominal thermal power, which is numerically equal to ~ 57-85% of the nominal electrical power of the generator of a power plant.

In this regard, and also taking into account the fact that the specific capital costs attributed to the unit of rated electric power produced for the construction of the well-known steam turbine CHP plants using fossil fuels (dol./kw el.) Are numerically approximately 5-6 times higher than those attributed to the unit of produced thermal power capital cost (US $ / kW heat.) required for construction (for srednepotentsialnogo heat with temperatures up to 220-300 ^o C) known fossil fuel boiler, the savings in capital costs for construction Each CHP-based steam-powered power plants operated according to the claimed method, will be at least 10-15% of the capital costs for construction purposes equivalent to rated electric power and considerably lower thermal load, which is based on the known steam-powered power plants. When compared with the construction option next to the well-known CHPP of the indicated additional boiler house operating on nuclear fuel, the expected savings in capital costs when implementing the proposed technical solution will be correspondingly higher.

 Moreover, taking into account the above ~ 11-15% annual savings in the inventive power plant of fuel irrationally burned in an additional boiler room, as well as taking into account the increase in the average annual heat utilization coefficient of fuel of the proposed electric power plant (based on the same nomenclature and the number of basic units of equipment similar to the known EU) the annual savings in operating costs of a CHP plant based on steam-powered power plants operated by the claimed method will be at least ~ 5% of annual operating costs Required during operation on the known solutions generated TPP with the same electric power and fossil fuel boiler, providing additional heat energy issuing consumer.

e) The steam-powered power plant operated by the proposed method has a higher independence of its heat loads (thermal power output to the consumer) from the power generated by its electric power, which is especially important in practice to ensure a sufficiently high thermal load of electric power while significantly reducing its electric load . So, for example, for the proposed power plant based on K, KT, or TK type turbines, a “painless” reduction of the power of the electric power generator of the electric power generator to ~ 15-65% of its rated power (N _nom.el. ) is allowed to be “painless” to maintain the nominal level of heat load (N for a power plant based on well-known steam turbines of the type PT or T, up to ~ 40-65% N _nom.el. .

 It should also be noted that the regenerative high-pressure heaters used in the proposed method for additional delivery of thermal energy to the consumer (in conventional power plants, their usual amount is from 3 to 6) are, like the well-known heaters of the network water of the thermal consumer, quite dimensional and metal-intensive pressure vessels occupying the corresponding production facilities at the CHP. For example, the height of each known regenerative heater of the PV type used in medium and high power ECs with a pressure in the vessel up to ~ 65-70 atm is 8.0-10.0 m, and the diameter is 1.7-2.2 m ( see, for example, the book "Nuclear Power Plants", T. Kh. Margulova, M., Higher School, 1969, p. 85). Therefore, the proposed alternate use of high-pressure regenerative heaters for heating feed water and for heat supply without the need for the well-known introduction of additional network water heaters into the installation, using steam taken from the turbine as a heat source and which should have approximately the same weight and size characteristics, is significantly beneficial in economic respect.

 Thus, taking into account the considered 3 options for the implementation of the proposed EA, the implementation of the inventive method of operating a steam-powered power plant that simultaneously produces electric and thermal energy ensures the achievement of the following positive production and economic indicators and characteristics in various industries.

1) During the periods of operation of the proposed steam-powered power plant based on well-known turbines of type K, KT, TK, T and / or PT in a mode with an increased output of thermal energy to the consumer, its maximum heat load (while increasing the average temperature potential of the generated heat and maintaining the nominal electric load - 100% N _nom. ) can additionally numerically increase compared to the nominal by ~ 40-60% of the nominal electric power of the generator of the installation, the thermal power of the boiler a or a steam generator which increases by ~ 10-17%.

In periods of reduced to ~ 90-95% N _nom. the electric load (due to a decrease in the efficiency of electric power plants due to the switching of regenerative high-pressure heaters used for heat supply to the high-pressure steam turbines), the maximum thermal load of electric power plants can increase numerically by ~ 50-75% of the nominal electric power of the generator of the unit ( at the same time, the thermal power of the boiler or steam generator EU increases by ~ 20-22% of the original).

 It should be emphasized that the implementation of the proposed method is economically ensured with the same nomenclature and the number of basic units of equipment of a well-known similar combined steam-powered power plant.

2) As a result of the transition (according to the claimed method of operation) of the steam-powered power plant to the mode of its operation with increased heat output to the consumer, the coefficient of heat utilization of the fuel of the EA increases for plants with different types of known steam turbines as follows:
for installations with turbines of the type KT, TK and / or KT - by ~ 6-27%;
for installations with turbines of type T and / or PT - by ~ 3-11%.

 3) The steam-powered power plant operated by the proposed method has a higher independence of its thermal load from the capacity of the generator of the plant generating electricity for another consumer than that of known similar power plants. This is confirmed by the fact that for the proposed power plant, based on widespread steam turbines of type K, CT and / or TK, a significant decrease in the power of the electric power generator to 15-65%, which is painless to maintain the nominal level of the total heat load, is allowed, and for electric power plants based on known steam turbines of type T and / or PT - up to 40-65%.

 It should be noted that in the case of operation of the proposed steam power plant in the basic mode with the issuance of almost nominal electrical load, for example, into the general power system, the additional controlled amount of heat supplied to the consumer obtained by the claimed method of operation can also be used constantly by the corresponding additional external consumers, and not serve as a means to compensate for the heat load deficit given by another consumer reducing the power of the electric power generator.

 4) Savings in capital costs for the construction of each TPP, based on steam-powered power plants operated by the claimed method, will be at least 10-15% of the total capital costs for the construction of TPPs with an equivalent nominal electrical power (and with a significantly lower maximum thermal load), which is based on well-known steam-powered power plants with turbines of types K, CT, TK, T and / or PT.

 5) The annual savings in operating costs of a CHP plant based on steam-powered power plants operated by the claimed method will be at least 15% of the annual operating costs required during operation of a CHP plant with the same electric capacity and a fossil fuel boiler, which provides the necessary additional output thermal energy consumer.

 To realize the abovementioned advantages, it seems appropriate not only to build new CHPPs on the basis of the proposed technical solution, but also, in connection with the minor modifications required by the claimed method of operation, mainly only part of the feed water path of the thermal schemes of power plants, upgrade existing CHPPs based on well-known steam-powered power plants that are currently being produced, for example, in Russia and other CIS countries, "83-85%" (see, for example, the book "Steam turbines us, "Andrey Scheglyaev A., M., Energoatomisdat, 1993, Vol. 1, p. 8) of the total produced by thermal and nuclear power plants electricity.

 The above production and economic indicators of the implementation of the proposed technical solution allow us to conclude about its relevance and fairly high competitiveness compared to well-known counterparts.

Claims (6)

1. A method of operating a steam-powered power plant, in which a compressed, for example, the liquid phase of the plant’s working fluid, mainly water, is sent to a boiler or steam generator, where at constant pressure due to the heat of the fuel it is heated until the necessary parameters are formed, which is then fed to the flow part equipped with regenerative steam extraction of the turbine, in which the process of expansion takes place, as a result of which the turbine drives, for example, an electric generator, then the exhaust steam or is sent to an intermediate superheater, after which it is supplied for work, for example, to the next at least one working cylinder of the turbine and then the condenser, or immediately sent to the condenser, where due to cooling by an external heat carrier the steam is converted into the liquid phase of the working fluid, which is then pumped in at least one regenerative low-pressure heater, then, if necessary, is supplied to a deaerator, then sent to the heated side of at least one surface regenerative heating The high pressure vessel is then again sent to the boiler or steam generator of the installation, in which, during its operation, with the delivery of thermal energy to the consumer, an additional part of the working fluid flow rate is also taken from the turbine, which is used
for transferring thermal energy to the consumer, characterized in that during operation of the installation in a mode with increasing the steam output for each value of thermal energy to the consumer, the working fluid of the installation is sent to bypass the heated side of at least one regenerative high-pressure heater, the heated side of the specified heater or heaters is switched into the composition of the circulation heat exchange circuit of the consumer of thermal energy and, accordingly, the di pazonu enthalpies heated in a boiler or steam generator, the working fluid, or increase the power of the boiler or steam generator when it is a predetermined steam power output, or concurrently increase the power of the boiler or steam generator and alter its steam output.  2. The method according to claim 1, characterized in that for regulating the power of thermal energy supplied to the consumer through regenerative high pressure heaters, the flow rate of steam taken from the turbine to the heating sides of these heaters is changed.  3. The method according to claim 1 or 2, characterized in that the heating side of at least one regenerative high pressure heater used to provide thermal energy to the consumer is switched to the selection of higher pressure steam. 4. A steam-powered power plant, comprising, for example, a boiler or a steam generator combined by, for example, circulating the working fluid of a plant, a flow part equipped with regenerative high-pressure and low-pressure steam turbines that drive, for example, an electric generator, which is then connected either to an intermediate superheater, then with the next at least one working cylinder of the turbine and then with a condenser, or directly with an exhaust steam condenser, cooled by an external heat carrier the body side of which is connected through a pump to at least one regenerative low-pressure heater, which is further connected, if necessary, to a deaerator and then to the heated side of at least one surface regenerative high-pressure heater of the working fluid, which is further connected to the input of the working fluid into the boiler or a steam generator, while the turbine is also equipped with cogeneration steam extraction, configured to provide the consumer with thermal energy, characterized in that the heated side of at least one regenerative high-pressure heater at the inlet and outlet of the working fluid is connected via shut-off devices to the circulation heat exchange circuit of the consumer of thermal energy, pipelines connecting the inputs and outputs of the heated side of the specified heater or heaters with their neighboring working main circulation path body units of equipment installation, equipped with locking devices,
and said units of installation equipment are additionally interconnected, bypassing the regenerative heater or heaters located between them, and also the shut-off devices, by a corresponding bypass pipe, which is also equipped with a shut-off device.  5. The installation according to claim 4, characterized in that, preferably, each pipeline that provides regenerative extraction of steam from the turbine to the heating side of the high pressure heater, configured to provide the consumer with thermal energy, is equipped with a shut-off and control device.  6. Installation according to claim 5, characterized in that the heating side of at least one of the specified regenerative high-pressure heater, configured to provide the consumer with thermal energy, is additionally connected through a shut-off and control device with the selection of higher pressure steam from the turbine.

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