RU2264581C1 - Method and system for natural gas preparation before supplying thereof to consumer with complex natural gas energy usage, energy-cooling plant, as well as energy drive with impeller machine, gas refrigerator and ice generator - Google Patents

Abstract

FIELD: pipeline systems for gas distribution, particularly with the use of excessive gas pressure reduced in gas-distribution stations and adapted to obtain electric energy, cold and ice without fuel combustion.

SUBSTANCE: method involves using gas cooled by expanding thereof in expander without external work performing as cooling agent to cool air in refrigerator compartments and in ice generator. Part of cold gas passes in ice generator heat-exchanger connected to energy-cooling plant outlet or to collector linked with outlet of each energy-cooling plant to obtain consumer-demanded gas temperature at ice generator outlet. System for above method implementation includes gas refrigerator with compartments and heat-exchangers arranged in each compartment. The heat-exchangers are connected one to another in series. Outlet of above heat-exchangers is connected to pipeline which conveys gas to consumer. The system is provided with at least one ice generator having heat-exchanger linked to outlet of corresponding energy-cooling plant or with collector connected to outlet of each energy-cooling plant and with pipeline adapted to convey gas to consumer. Energy-cooling plant has turboexpander and electric generator, energy drive with impeller machine, gas refrigerator and ice generator used in the system.

EFFECT: increased efficiency of gas cold usage and environmental safety.

31 cl, 5 dwg

Description

Technical field

The group of inventions relates to the field of power engineering and is intended for the use of natural gas in the means of generating mechanical energy and cold due to the use of differential pressure of natural gas, mainly in the places of its production, at gas distribution and compressor stations.

State of the art

The use of natural gas in mechanical energy generation systems is known (see, for example, Overview. Series: “Use of Gas in the National Economy.” “Utilization of Potential Gas Energy at Gas Distribution Stations and Expander Installations,” issue 4, 1988, p. .20-30; G.E. Zarnitsky. "Theoretical foundations of the use of pressure energy of natural gas. - Nedra, 1968, p. 201, Fig. 66; Stepanets A.A." Energy-saving turbine expander ". Nedra, 1999 .).

The essence of the known technology lies in the fact that natural gas having a high pressure is sent to an expander, where the gas expands and does the work that is used to drive various mechanisms, such as pumps, generators or transformers, into the energy stored, for example, in electric batteries. In addition, the decrease in gas temperature caused by its expansion is used for cooling in external refrigeration units. This technology allows you to increase the efficiency of natural gas use, but its application raises a number of problems.

One of the main problems concerns the use in the known technology of technical means for using the differential pressure of natural gas, in particular expander units. Well-known installations, as a rule, turn out to be complex in design to manufacture, requiring for their work a whole range of auxiliary systems using various technological agents (lubricating oil, water, heat, electricity, etc.), which as a result makes the expander installation complex in structure, costly and unreliable in work. So, for example, a turboexpander is known, made in the form of an electric drive with a blade machine, comprising a housing with a rotor installed in it, mounted on a shaft with bearings, a guiding apparatus with nozzles for supplying and discharging a working fluid (gas) and high and low pressure manifolds, a sealing system shaft, regulation, control and protection system (Pipeline transport of oil and gas, Edited by V.A. Yufin. - M .: Nedra, 1982, pp. 123-126; A.A. Stepanets "Energy-saving turbine expander", Nedra , 1999).

In the known solution, there is no method and means of adapting the energy drive to the volumes of gas flows by pressure, which varies over a wide range at the inlet of the energy drive (turboexpander), and its operation is carried out at increased rotor speeds, i.e. in suboptimal modes, which requires for transmission of energy, for example, the generator to use a gearbox with a high gear ratio, which, as noted, complicates the installation with all the ensuing consequences.

The use of a traditional gas-oil-type rotor shaft seal at high shaft rotation speeds necessitates the installation of a separate complex sealing system including a seal unit, two pumps, a gas-oil differential pressure regulator, an oil accumulator, a heat exchanger, a degasser, an oil and gas return system and etc.

The full bore turbo expanders used are very sensitive to deviations from the calculated volume of gas and pressure passing through them. When reducing the pressure and volume of the passing gas through a turboexpander, its power and efficiency first sharply decrease, and then it stops. In addition, high-speed blade machines require correspondingly high-precision production for their manufacture and special operating conditions.

The above and other disadvantages of the known technical solutions are mainly eliminated in the method and device by technical solutions known from the patents of the Russian Federation No. 2056555 for class. F 16 H 41/00, 1996, No. 2098713 for the same class, 1996, and certificate for a utility model of the Russian Federation No. 20778 dated April 9, 2001.

The closest of them to the proposed method and system is a method of preparing natural gas for supply to the consumer with the integrated use of natural gas energy by expanding the natural gas in the expanders, removing the mechanical energy of the expanders to drive the generator and passing the gas cooled in the expander to the consumer through the refrigeration heat exchanger installations, as well as a system for implementing this method, containing electro-refrigerating units (ECA), each of which includes an expander p and its associated with the shaft generator, and refrigeration unit, a heat exchanger connected to the outlet, at least one of the ECA and to which is connected a pipe for supplying gas to the consumer (RF Patent 2098713).

The closest to the proposed energy-refrigerating unit is an ECA containing a sealed chamber with an outlet pipe, a turboexpander installed in it and an electric generator connected to its shaft, a sensor for the rotational speed of the turboexpander shaft, a throttle-metering device for supplying gas to the nozzles of the turbine expander, a regulator connected to it gas supply and an electronic unit associated with the specified sensor and regulator (RF certificate No. 20778).

The problem is that when the potential energy of the gas pressure in the turboexpander is released, the thermodynamic parameters of the gas change, which can go beyond the acceptable limits for normal operation both for the expander and gas transmission system, as well as for the gas consumer’s technical equipment.

In known solutions, the operation of the expander unit is carried out at high degrees of gas expansion (from 8 to 12 times), which leads to a deep decrease in the temperature of the gas stream at the outlet of the unit. Moreover, if the gas at the inlet of the installation will be supplied with a temperature of 0 ° C, then at the output of the installation it will reach minus 90-120 ° C, and this will require the use of special cold-resistant steels, which will sharply increase the cost of the installation, and gas with such a temperature it is impossible to transport through conventional gas pipelines and even more so impossible to use with consumers. Therefore, the known technical solutions provide for heating the gas at the inlet to the expander installation to about 100 ° C due to the use of useful thermal energy, for example, by the power plant, then the gas at the outlet of the installation has a temperature of minus 10-20 ° C and conventional high-quality steels are used in the construction. However, as follows from the laws of thermodynamics, the mechanical energy received from the expander and the usable useful thermal energy (steam or hot water) are not only equal, but the thermal energy exceeds the mechanical energy by the amount of energy, determined by the efficiency of the heat exchanger and the need to transport the coolant to the expander and back. Thus, such a system is energetically insolvent - unprofitable. It is possible to increase the temperature of the gas at the outlet of the expander by reducing the degree of expansion of the gas, but this will lead to the underutilization of the available gas pressure energy. Therefore, in the closest solution, it was proposed (RF patent No. 2098713) that gas expansion and energy extraction be carried out stepwise in several expanders connected in series, and with an interstage supply of heat to the gas. In this case, the medium-temperature (minus 20-30 ° C) cold that occurs when the gas expands in the expander can no longer be considered as a negative phenomenon and not be combated, but it is useful to use it, for example, for refrigerated storage of food products. This together will increase the efficiency of using excess gas pressure energy at reduction stations (waste energy) by almost a factor of two than when using it only in an expander installation for generating mechanical or electrical energy.

The next problem concerns technology and technical means that will make it possible to use the cold generated during gas expansion in expander units, in particular in refrigerators for chilled food storage, freezers and ice makers. Famous refrigerators use chemicals (ammonia, freon, etc.) as the refrigerant, the inevitable leaks of which negatively affect people's health and worsen the environmental situation. Currently, the use of such refrigerants is prohibited by international authorities and a search is underway for new, more environmentally friendly refrigerants.

Famous refrigerators are complex, expensive during the construction and operation of facilities, which can be divided into two parts: 1) refrigeration and compressor unit with infrastructure (receiving, storage, refrigerant supply systems; systems for receiving, storing, moving, circulating and regenerating lubricating oils, systems for supplying cooling water, its cooling, circulation or discharge into drains; power supply system; buildings with heating, lighting, ventilation, water supply, sewage systems, etc.); 2) the refrigerator itself, which has chambers for storing food, equipped with heat exchangers with air circulation, doors, lighting, corridors for transporting goods, etc. In the known solutions do not use natural gas with a low temperature as a refrigerant for cooling the chambers of refrigerators designed to store food. Natural gas is not a toxic substance and its use as a refrigerant in combination with expander units can allow the creation of highly efficient environmentally friendly, less expensive refrigerators with a simplified structure.

Known gas refrigerator containing a heat shield, chambers with a closed opening and heat exchangers, air coolers (see [2] p.197, 198). However, it does not provide heating of the chilled gas to a temperature ensuring its normal use by the consumer.

A known ice maker containing a thermally insulated chamber, in the lower part of which there is a drop former with means for spraying water, a fan placed in a thermally insulated channel, a heat exchanger mounted on the drier, cooling plates placed in the chamber, and an ice receiving device in the lower part of the chamber (ed. St. USSR No. 411277, F 25 C 1/18, 1974). The known ice machine has a complex cooling system, and this, in combination with spraying water in the lower part of the chamber, does not allow efficient use of the entire volume of the chamber to form ice.

Another problem concerns the objective inconsistency in the seasons of the year generated by the differential pressure of gas energy and cold with the needs for cold. It is during the cold season that the largest amount of gas is consumed, and, therefore, more gas passes through the expander units, and, therefore, more energy and cold is generated, and the demand for cold at this time naturally decreases. This can lead to hypothermia of the gas entering the pipeline after the expander units, and, as mentioned above, to violations of gas parameters, technology, and other negative consequences. In order to prevent this from happening, it is necessary to reduce the power of the energy refrigerating unit (turn off one or several units) without using the energy of that part of the gas stream that does not pass through the expander units, which is very undesirable; or find a new technical solution to this problem.

SUMMARY OF THE INVENTION

The objective of the invention is the creation of a range of technical solutions that provide the most efficient technology for using energy from the technological pressure drop (waste energy) of a natural gas source. In this case, the method used in this technology should be carried out using standard serial production equipment, and the devices used should be improved and unified elements of this equipment.

The technical result achieved using the proposed method, system and gas refrigerator is to increase the efficiency of the beneficial use of cold coming out of the ECA gas and providing the gas temperature at the system outlet necessary for its normal use by the consumer without special heating.

The technical result in terms of the energy refrigerating unit and the power drive is to provide the ability to achieve rated power at various parameters of the gas stream.

The technical result achieved using the proposed ice machine is to simplify the design and increase the efficiency of using the volume of the chamber.

The technical result is achieved by the fact that in the method of preparing natural gas for supplying a consumer with the integrated use of natural gas energy by expanding natural gas in at least one expander of an electro-refrigerating unit (ECA), removing the mechanical energy of each expander to drive an electric generator of the corresponding ECA and transmitting leaving the ECA cooled in the expander of the gas before supplying it to the consumer through at least one heat exchanger of the refrigerator, according to the invention I use a refrigerator with chambers, in each of which a heat exchanger is placed, cold gas is passed sequentially through the heat exchangers of the refrigerator chambers, and part of the cold gas is passed into an ice generator heat exchanger connected to the output of the corresponding ECA or to a collector connected to the output of each ECA to obtain an ice generator at the output gas temperature, ensuring its use by the consumer.

The degree of expansion of the gas in each expander is selected from the condition of ensuring the specified temperature of the gas at the inlet to the heat exchangers of the refrigerator and the ice maker.

In addition, if the degree of expansion of the gas in the expander or expanders is insufficient to provide a given gas temperature at the inlet to the refrigerator and / or ice machine, it is advisable to connect a stand-alone refrigerant manufacturer to the refrigerator and / or ice machine, respectively.

In addition, it is desirable that a system including at least one of the indicated expander, an electric generator, a refrigerator and an ice generator is connected to a natural gas source and to a gas supply pipe to a consumer in parallel with a gas reduction station (GDS) to reduce the load on it and maintain required parameters of gas supplied to the consumer.

When using more than one expander and when the amount of gas passing through the GDS exceeds the amount of gas passing through the specified system, it is advisable to bypass a part of the gas past the system and measure the temperature of the gas after mixing the gas flows, and if the temperature drops to an acceptable level, reduce the proportion of gas passing through the system by disconnecting part of the expanders.

The technical result is also achieved by the fact that in a system for preparing natural gas for supplying a consumer with the integrated use of natural gas energy containing at least one energy-refrigerating unit (ECA), each of which includes an expander and an electric generator connected to its shaft, at least at least one gas refrigerator, the heat exchanger of which is connected to the outlet of at least one ECA, and the pipeline for supplying gas to the consumer, according to the invention, the gas refrigerator contains chambers, in each of which a heat exchanger is placed, heat exchangers are connected to each other in series, and the output of the heat exchangers is connected to a pipeline for supplying gas to the consumer, and the system is equipped with at least one ice generator, the heat exchanger of which is connected to the output of the corresponding ECA or to a collector connected to the output of each ECA, and with a pipeline for supplying gas to the consumer.

The technical result is also achieved by the fact that in an energy-refrigerating unit containing a sealed chamber with an outlet pipe, a turboexpander installed in it and an electric generator connected to its shaft, a turboexpander shaft speed sensor connected to a gas supply pipe, a throttle-dispenser for supplying gas to the nozzles of the turbine expander, the associated gas supply regulator and an electronic unit associated with said sensor and regulator, according to the invention, the turbo-expander nozzles are divided into two or more groups, one group of nozzles is connected to the gas supply pipeline through the specified metering throttle, and the other or others through the collector or through an additional metering throttle or metering throttle.

In addition, a gas-operated shutter with an automatic control system is installed on the gas supply line to the turbo-expander with a smooth opening operation when the generator is loaded and quickly closed by a signal from the automation system, formed by an external switch on or by a protection unit when the operating parameters of the unit and processes deviate beyond specified limits with the possibility of simultaneously removing the load from the generator and closing the shut-off body.

In this case, the turbo-expander has a strength calculated for the highest accepted level of gas pressure, and the chamber has a strength calculated at a pressure less than the highest accepted by the magnitude of the degree of expansion of the gas in the turbo-expander.

At the same time, a gas reducer can be installed on the gas supply line to the turbo-expander to maintain its pressure not higher than the required one, and safety valves can be installed on the outlet pipe connected to the chamber, which can be activated when the gas pressure in the chamber rises above the specified level, for which the strength of the chamber was calculated, and their total flow area selected is greater than the cross section of the nozzles of the turbo expander.

The chamber has dimensions determined on the basis of the dimensions of the electric generator of the highest power in the used power range, and the turboexpander has the dimensions of the flow part and the power calculated from the condition that the electric generator reaches its rated power at the lowest specified gas pressure at the inlet to the turbine expander.

In addition, at a minimum, but sufficient for the turbo-expander to develop a predetermined gas flow from the source, the throttle-dispenser is connected to one group of nozzles and to a gas supply pipe to the turbo-expander equipped with said shut-off element, and the unit is equipped with a collector connected to the other groups of turbo-expander nozzles and with the specified pipeline for supplying gas to the turbo-expander for starting, putting the generator in synchronism with the external network and developing power 5-10% of the nominal when supplying gas through the jail sel dispenser for the full load of the generator with additional gas supply through the collector.

At high source gas pressures, one or more metering throttles connected to one or more groups of nozzles are connected to a manifold connected to a gas supply line to the turbo-expander to provide gas supply through the metering throttle or metering throttle when regulating the gas supply to nozzles during start-up and commissioning of the generator in synchronism with the power grid, and at its rated load and other operating modes of the unit.

In both cases, the flow part of the turboexpander has parameters, namely, the number and sizes of nozzle groups and pipelines included in it, connecting them to the outlet of the collector or with the throttle-dispenser, calculated from the condition of ensuring optimal efficiency when the gas pressure at its inlet changes in 4-5 times, gas consumption by 4-6 times and turbine expander power by 3-4 times.

In this case, the generator is made with the possibility of using it when starting up the unit as an electric motor and untwisting its rotor and turbine expander shaft when voltage is supplied to it from an external power supply to a frequency synchronous with the power supply network and with the possibility of transition after that and after gas supply to the turbo-expander nozzles from engine mode into the generator mode with the equality of the power consumed by the unit and the power it produces and reaching the nominal mode.

The technical result is also achieved by the fact that in the power drive with a blade machine - a turboexpander containing a housing mounted on the rotor shaft with rotor blades mounted on the nozzle housing, directed to the rotor blades, a metering throttle and a rotor shaft speed sensor associated with gas flow regulator through the metering throttle, nozzles are divided into several groups, one group of nozzles is connected to the gas supply pipe through the specified metering throttle, and the rest is through a manifold connected to the shut-off device nom.

In this case, the number of nozzles connected to the gas supply pipeline during operation of the power drive is determined on the basis of the conditions for achieving the rated power with maximum efficiency at the lowest pressure of the source gas.

In addition, the degree of expansion of the gas is selected based on a given temperature of the gas at the output of the power drive at the highest temperature of the gas entering the power drive from the source.

The technical result is also achieved by the fact that in a gas refrigerator containing heat-insulated chambers with a closed opening and heat exchangers, according to the invention, a heat exchanger and a fan are placed in each chamber, to ensure storage of products at different temperatures, heat exchangers are connected in series and installed on the pipelines for supplying cold gas to each heat exchanger locking and regulating bodies with the ability to maintain in the first along the cold gas chamber the lowest air temperature ha and successively increasing air temperature in subsequent chambers.

In addition, each chamber can be equipped with an air temperature control system associated with temperature sensors located in the chamber, with a shut-off regulating body and with a fan with the possibility of changing the supply of cold gas to the heat exchanger and / or the fan rotation speed depending on the set and actual air temperatures in the cameras.

Moreover, if the temperature of the supplied cold gas is not low enough, at least one chamber can be connected to an autonomous refrigeration producer with the possibility of taking part of the air from the chamber, cooling it and returning it to the chamber to maintain the set temperature in it.

To periodically thaw the heat exchangers, the outlet pipe of each heat exchanger can be connected through a shut-off element to the hot air blower connection unit, and a discharge candle can be connected to the heat exchanger inlet through the shut-off element to exit the gas exchanger first, and then hot air.

In addition, methane concentration sensors can be installed at the upper points of each chamber, which are connected through a signal converter-amplifier to an automation and protection system connected to a shut-off element installed on the gas supply pipe to the corresponding heat exchanger, as well as to an exhaust ventilation system.

It is advisable that the heat exchangers and pipelines located inside the chambers are made without detachable connections, and the shut-off bodies are placed outside the chambers.

The technical result is also achieved by the fact that in an ice machine containing a thermally insulated chamber, in which a droplet former with a means for spraying water is placed, a fan, a heat exchanger and an ice receiving device in the lower part of the chamber are located in the thermally insulated channel, according to the invention, the heat exchanger is placed in the said thermally insulated channel and connected to pipelines for supplying and discharging cold gas with locking elements, the specified channel is connected by its inlet to the upper part of the chamber, and the outlet - with holes in the side walls of the chamber to enter the chilled air chamber.

In addition, the droplet can be connected to another heat exchanger to supply water cooled with cold gas.

The device for receiving ice is an ice storage device in the form of a tank located at the bottom of the chamber with inclined walls and a balancer, mounted on an axis and connected with a fixing device with the possibility of unlocking and tipping the drive when filling it with ice due to the asymmetry of the drive and the return of the drive freed from ice to the starting position due to the moment from the balancer and fixing the drive.

In this case, the inner surfaces of the ice maker chamber and the storage tanks are preferably coated with a water-wettable material, for example Teflon.

The ice maker can also be equipped with a conveyor belt and an ice storage located under the drive, in which a transportable distributor is installed for feeding ice briquettes onto it from the drive using a conveyor belt, and other belt conveyors are attached to the distributor for laying ice briquettes on the ice storage floor one on another or on shelving.

In this case, the entrance to the ice storage can be combined with the exit for ice from the chamber, and an ice crushing unit can be installed at the exit from the ice storage to turn ice briquettes into marketable ice of a given structure.

Thus, the complex use of natural gas energy when it is supplied to the consumer is carried out through an expander connected to the high pressure pipeline, in which natural gas expands with decreasing temperature and mechanical energy is removed to drive the energy consumer, for example, an electric generator, and then the cooled gas passes through the heat exchangers of the refrigerator and the ice maker in which it is heated, its temperature rises, and then it enters the pipeline that discharges gas to consumers. Moreover, according to the invention, gas is supplied to consumers through one or more expanders connected in series, parallel or combined, the temperature difference of the gas stream passing through the expander is measured, and depending on the value of this difference, the gas stream is directed either to a heat exchanger, where it is heated by cooling the surrounding air, or to the next series-connected expander. At the output of the expander, into which the gas stream enters after passing through a heat exchanger, it is advisable to maintain the gas temperature in predetermined limits. For this, it is possible (depending on the degree of expansion of the gas in the expander) to set the gas heating mode in the heat exchanger, compensating for its subsequent cooling in the expander.

To solve this problem, an energy-refrigerating unit is also proposed, including an expander that generates mechanical energy, a consumer of mechanical energy, for example, an electric generator, a gas supply and exhaust system, a unit operating mode control system, etc.

From such units at gas facilities it is proposed to create power units in the form of series-connected gas pipelines, if the possible degree of gas expansion exceeds four, several energy refrigeration units, each of which should have a heat exchanger with inlet and outlet pipelines along the gas, while in the inlet pipeline a shut-off element is installed in front of the heat exchanger, and the inlet and outlet pipelines are connected by another pipeline to the shut-off element for the possibility of direction along current to the heat exchanger bypass

The degree of gas expansion in the expander of each energy-refrigerating unit should be such that the gas temperature after expansion should be in a predetermined interval suitable for direct beneficial use of the cold contained in the gas stream. For example, when using the arising cold in the refrigerator for storing food, the gas temperature should be in the range of minus 20-30 ° С. With a possible degree of gas expansion at the facility within 1.8-2.5, the inputs of the expanders of energy refrigerating units included in the unit can be connected by pipelines to one collector that is connected to a high pressure gas source, and the outputs also to one low pressure collector ( i.e. in parallel), to which the heat exchangers of the refrigerator, ice maker and other cold consumers are connected by pipelines, after which the gas is sent through the pipeline to the consumer. With flow volumes greater than the gas passage through one expander of the unit, and high (more than 4) pressure ratios of the source and consumer of the gas, several energy-refrigerating units can be connected by pipelines to the collector of the high-pressure gas source, and behind each unit thus connected to the source high-pressure gas, connect one or more units with heat exchangers, as described above. At the same time, the outputs of each last expander in this circuit should be connected to the low-pressure gas manifold from which it is sent to use the cold.

In all the above-described schemes for connecting energy-refrigerating units, it must be possible to shut down both each unit and the unit as a whole without disrupting the gas supply to the consumer. This can be achieved through a gas bypass pipe connected to a high pressure gas pipeline and connected to the inlet and outlet pipelines of each heat exchanger. Moreover, in these pipelines and in the bypass piping, shut-off elements must be installed in such a way that in the event of a decrease in the pressure of the gas source or an emergency situation causing one or all of the units to stop, the gas flow could be bypassed any expander, as well as the heat exchanger, while in the gas pipeline in front of the bypass pipeline connection unit, a block of pressure reducing valves (pressure reducers) must be installed.

A turbo expander, i.e. a blade machine containing a housing with gas supply and exhaust pipelines, a rotor with blades mounted on a shaft connected to the electric motor shaft by means of a coupling, a nozzle apparatus divided into groups, gas jets after which interact with rotor blades, a gas flow meter dispensed by pipelines with nozzles, a dispenser control system for regulating gas flow, which includes a modulator with a rotor shaft speed sensor connected via an electronic unit and a signal amplifier to an actuator the property providing the required change in the bore of the dispenser during start-up, exit, and maintenance of the nominal idle speed and load change.

It is advisable to connect the rotor shaft with the energy consumer shaft in the form of a synchronous radial magnetic coupling, consisting of two half-couplings, separated by a sealed screen of non-conductive or high-resistance material, and when placing a turboexpander and an energy consumer (electric generator) in a sealed chamber (capsule) filled with gas during operation It is advisable to connect the shafts of the energy-refrigerating unit using a soft finger coupling (see certificate for utility model of the Russian Federation No. 20778).

The gas flow meter can be made in the form of a rotary or spool throttle located in the housing with a drive from a lever or electromagnetic system. At sufficiently high pressure of the gas source, it is desirable to supply the entire stream to the turboexpander through a controlled gas meter at all operating modes from start-up to full load, and at low gas source pressures, it is advisable to supply only part of the gas stream through the meter, i.e. to one of the nozzle groups to ensure the start-up of the unit, output to the rated idle speed and their maintenance, synchronization of the generator with the mains and partial load reception. Further increase the load by smoothly opening a controlled shut-off device and supplying gas to the other groups of nozzles of the turboexpander. It is desirable that this controlled locking device be able to open slowly (30-40 s) and close quickly (0.3-0.5 s). In this case, it can be used in the protection system of the unit when its defining parameters deviate from the permissible limits.

It is advisable to use the cold generated during gas expansion in the expander for cooling the refrigerator chambers due to the passage of the cold gas stream (minus 20-30 ° C) as a refrigerant through heat exchangers located in the refrigerator chamber. Moreover, in the case of the sequential inclusion of expanders in the high pressure gas pipeline, the heat exchangers of the refrigerators are connected after each expander, i.e. after each stage of gas expansion, and when several turbo-expanders are connected in parallel, it is desirable to connect them by pipelines to one collector connected to a high-pressure gas source, while the gas outlet from each expander to be connected by pipelines to another low-pressure manifold from which gas is supplied to heat exchangers, and then, after heating, gas should be diverted into the gas supply line to the consumer.

In order to make the fullest possible use of the cold expanders during operation, it is desirable to have low-temperature chambers (minus 18-20 ° C), chambers with medium (minus 7-8 ° C) and high temperature (minus 2 or plus 2 ° C) food storage in the refrigerator . In this case, the heat exchangers in these chambers are connected by pipelines in series, and gas must be discharged into the consumer’s pipeline after the chamber with the highest temperature.

Further, in the cool and cold season, the excess of cold formed during the full load of energy-refrigerating units is used for ice production and stored for intensive use in the trade of chilled products in the warm season.

For this purpose, according to the invention, it is advisable to direct the excess (after ensuring the operation of the refrigerator) part of the cold gas stream to the heat exchanger of the ice generator, in which the process of continuous freezing of water droplets sprayed with nozzles in the air space of the heat-insulated chamber of the ice generator is organized. Moreover, it is proposed to drop water drops from the nozzles towards or at an angle to the cold air stream coming from the heat exchanger. Drops of water after freezing will fall down the chambers and, as proposed in the invention, will accumulate in a special tray, which, after filling, tilts around the axis, dropping the ice briquette onto the conveyor, through which it moves into the ice storage adjacent to the ice maker and is stored using a distributor and conveyor systems. Commercial ice of a given structure is proposed to be formed from stored ice by crushing it using ice crushing units.

Thus, it is shown that the features that characterize the invention are significant and aimed at solving a single problem - the most efficient and integrated use of the energy of the pressure drop of a natural gas source, i.e. "waste" energy of the gas stream, which is currently dissipated in large quantities during the reduction of gas pressure in gas distribution systems.

Brief Description of the Drawings

The group of inventions is illustrated by drawings, where:

figure 1 shows a block diagram of the proposed system of energy-refrigerating complex;

figure 2 - energy refrigerating complex, functional diagram;

figure 3 - energy refrigeration unit, functional diagram;

figure 4 - gas refrigerator, functional diagram;

figure 5 - ice maker with ice storage, functional diagram.

Preferred Embodiment

Figure 1 presents a block diagram of a system that implements the proposed method, an energy-refrigerating complex, showing the relationship of its components with each other and GDS. As can be seen, the energy-refrigerating complex includes a power unit 100 of energy-refrigerating units, a gas refrigerator 101 and an ice maker 102 with an ice storage 103. All these components are connected by gas pipelines to each other and to the gas pipelines of the GDS 104 (dashed lines). Each object that makes up the energy-refrigerating complex produces its own positive effect:

- power unit 100 - electricity and cold;

- gas refrigerator 101 - cold storage volumes for food;

- ice maker 102 - marketable (water) ice.

After being cleaned, the high-pressure natural gas enters the turboexpander of the energy-refrigerating unit, in the nozzle apparatus of which the potential energy of the gas is partially converted into kinetic energy with a decrease in its temperature. The jets of gas at a high speed act on the blades of the rotor of the turbo expander, bringing it into rotation, which, in turn, performs work on external objects, for example, drives an electric generator. The difference in gas temperature at the inlet and outlet of the turboexpander is determined by the degree of expansion of gas in it. Then the gas, as a refrigerant, is sent to the heat exchangers of the refrigerator or to the heat exchangers of the refrigerator and the ice maker at the same time. It depends on the amount of gas passing through the turboexpander. The degree of expansion of gas in each turboexpander is assumed to be the same and in magnitude sufficient for the required reduction in the temperature of the gas stream for use as a refrigerant for a refrigerator and an ice maker. This temperature difference is measured, and if necessary, for a deeper cooling of the gas stream, it is sent not to the heat exchanger of the refrigerator, but to the next series-connected turbo expander, in which the second stage of gas expansion is realized, and then sent to heat exchangers for useful use, etc. In the event that the gas pressure drop is insufficient for the required cooling of the gas stream, air with a lower temperature is additionally supplied to the refrigerator chambers from a low-power independent compressor refrigeration unit so that after mixing the air cooled in the heat exchangers with gas refrigerant and the air supplied Additionally from this unit, the air temperature in the refrigerator compartment has reached the required level.

For the fullest use of the gas generated during expansion in a turboexpander, directed with the gas flow to the heat exchangers of the refrigerator, i.e. To ensure the greatest heating of the gas, chambers are placed in the refrigerator in series, in which it is necessary to maintain different levels of air temperature. Moreover, the heat exchangers of the chamber with the lowest air temperature circulating in it, for example, minus 18-20 ° C, are connected first to the source of cold gas - a turbo-expander or low-pressure gas collector, for example, minus 18-20 ° С, then heat exchangers of the chamber in which air with higher temperature should circulate are connected in series minus 7-8 ° C and finally connect the heat exchanger of the chamber, in which air should circulate with a temperature of about 0 ° C. This is how the controlled and most complete selection of cold produced by turbo expanders is made. After that, gas with the required pressure and temperature, which is in the acceptable range based on ensuring normal operating conditions for equipment, technical means and equipment of the gas transmission system and gas consuming objects, is sent to the pipeline supplying gas to the consumer. It is known that the minimum gas consumption falls on the summer warmest period of the year, and it is at this time that refrigerators operate most intensively, and they need the maximum amount of cold. In this regard, the calculation of the supply of refrigerators with cold is carried out to minimize the passage of gas through the turbine expanders. During this period, the ice maker is turned off or turned on with minimal productivity. With a decrease in the ambient temperature, the refrigerator’s need for cold somewhat decreases, and gas consumption increases, and consequently, the gas flow from the high pressure source to the consumer through the energy refrigerating complex also increases. This leads to an increase in electric power and cooling capacity, and, consequently, to an excess of cold. In such periods, an ice machine is used, which uses time-varying excess cold to produce ice, which is partially consumed, and is mainly sent to the ice storage for accumulation by the summer period - when the demand for it is especially high.

In parallel with the gas refrigerator and the ice maker, a gas flow regulator is included in the gas system along the bypass line between the low-pressure gas collector after the turbo-expanders and the gas outlet pipe to the consumer, which maintains a steady-state gas pressure in the specified manifold than in the gas outlet pipe to the consumer with a decrease in gas passage through the refrigerator and the ice maker. Such a scheme provides the most constant and full load of energy-refrigerating units, and consequently, the greatest power generation, regardless of fluctuations in the needs of the refrigerator and the ice maker in cold gas. In the event that the pressure of the gas source exceeds the calculated operating pressure of the energy-refrigerating unit, then a pressure reducing valve is installed at its inlet, with which the gas pressure at the inlet to the unit is reduced to the calculated value. According to the invention, with a two-stage (sequential) scheme for switching on energy-refrigerating units by connecting the gas inlets and outlets to the heat exchangers of the refrigerator and the ice generator by pipelines (equipped with shut-off bodies), they can be operated during operation from each of the two turbo-expanders, with any one working turbo-expander, as well as during selection gas to these heat exchangers only after the second turbo-expander when two turbo-expanders are operating.

Thus, before entering the consumer, high-pressure gas, in addition to transferring mechanical energy, performs a useful function of the refrigerant in refrigeration devices, and only after such complex use of its energy potential does it reach the consumer with the required reduced pressure and temperature acceptable for the transport and use process. To prevent the flow of gas directed to the consumer with an unacceptably low temperature in the case of a significant decrease in its passage through the refrigerator and the ice maker, a temperature sensor with a limiter is installed at its inlet, the pulse from which enters the automation system, which sequentially turns off the energy-cooling units until the gas temperature is above the permissible level.

The system that implements the method is a power unit of energy-refrigerating units, a functional diagram of which is shown in figure 2. The power unit is connected to a high-pressure gas source through a supply pipe containing sequentially arranged shut-off element 1, a filter 2, a heat exchanger 3, a throttle valve block 4, and connected to a gas supply pipe to a consumer through a metering device 5 and a shut-off shut-off element 6. To pipelines, connecting these elements, at points A, B, C, pipelines are connected with locking bodies 7. In addition, two locking bodies 8 are installed in this connection system.

The pipeline connecting the locking elements 7 is connected to a gas reducer 9, behind which there is a locking and regulating body 10 located at the inlet of the first energy-refrigerating unit, consisting of an electric drive with a blade machine - a turboexpander and an electric generator. The power drive includes a gas throttle-metering device 11, a turbo-expander 12, a rotor speed regulator 13 of the turbo-expander rotor shaft, mechanically or electrically connected to the throttle-metering device 11. The shaft of the turboexpander 12 with the rotor mounted on it (blade machine) is connected, for example, via a coupling, to the shaft generator 14. If, at the same time, at the inlet from the heat exchanger 16, the temperature of the carrier gas does not exceed 0 deg. C, which depends on the set mode of its heating in the heat exchanger 16, then the output of the next turbo expander 12 will retain the same gas temperature difference 12-25 ° C as at the output of the previous turbo expander 12 and in the next heat exchanger 16 of an external refrigeration device (gas refrigerator or ice generator) the same conditions as for the previous heat exchanger 16 are realized, conditions for effective cold removal, i.e. minus 12-25 ° C.

If it is necessary to obtain very low temperatures (minus 25-40 ° C) in the chambers of external refrigeration devices, the gas, as noted above, is sent to the next turboexpander 12, bypassing the heat exchanger 16. Otherwise, if the need for cold is less than the available refrigerating capacity, the gas after cleaning Before entering the turbo-expander system, the gas expansion in the turbo-expander is preheated or reduced.

Due to the fact that the volume of natural gas has seasonal fluctuations, the value of constant cold removal is calculated by its minimum value. In order to make the fullest possible beneficial use of the cooling capabilities of the power unit, an ice maker with an ice storage box is connected in parallel with the gas refrigerator, in which an ice reserve is formed in the autumn-winter-spring periods when the refrigerating capacity exceeds the cold demand. This stock is mainly used in the summer.

Thus, before entering the consumer, high-pressure natural gas, in addition to transferring mechanical energy to external devices, functions as a coolant of external refrigeration devices to ensure the required temperature regime of refrigeration chambers, and enters the pipeline leading to the gas consumer under reduced pressure and with such a temperature, which are permitted by the operating conditions of the relevant equipment used in gas production sites or at gas distribution stations.

The output of the turboexpander 12 through the check valve 15 is connected to the inlet to the heat exchanger 16 by a pipe 17, in which a controlled shut-off element 18 is installed in front of the heat exchangers 16. The inlet pipe 17 and the outlet pipe 19 of the heat exchangers 16 are connected by controlled shut-off bodies 20. This arrangement of the shut-off bodies 18 and 20 allows the gas stream that has passed the expansion stage in the turboexpander 12, either enter the heat exchangers 16, or, bypassing them, to the next expansion stage. Between the check valve 15 and the inlet pipe 17 of the heat exchanger 16, a condensate collector 21 can be placed, made, for example, in the form of a tank with a float valve, from which gas condensate flows through a separate pipe into a common storage tank.

The outlet pipe 19 of the heat exchanger 16 of the first gas expansion stage is in communication with the next turbine expander 12, which enters the second gas expansion stage containing the same structural elements as the first expansion stage, as described above.

In the last stage of gas expansion, the outlet pipe 19 of the heat exchanger 16 is communicated by a pipe 22 through a shutoff member 8, a metering device 5 and a shutoff member 6 with a gas line leading to the consumer.

The number of stages of gas expansion is selected based on the pressure of the gas source, the pressure at which the gas must be transferred to the consumer, the needs of the cold receiver and other conditions. However, the method implemented by this device allows you to use some optimal number of stages of gas expansion for any operating conditions, if this device provides design features that characterize particular cases of its implementation.

So, a bypass pipe 23 can be introduced into the power unit structure, connected to the gas supply line to the first between the gearbox 9 and the first shutoff body 10 and communicated with the inlet 17 and outlet 19 pipelines of each of the heat exchangers 16. At the same time, shutoff pipelines 17 and 19 are installed bodies 24 and 25, respectively, and shut-off bodies 26 and 27 are installed in the bypass pipe 23 in such a way that in the event of a decrease in gas pressure at the inlet of the gas main or an emergency that causes the shutdown of one or more energy refrigeration units, the gas flow could be directed to the consumer, bypassing any turboexpander 12, as well as the heat exchanger 16.

The presence of the bypass pipe 23 allows the optimal number of units to be used in all cases, and in emergency situations, the permissible cooling regimes in the cold rooms and the pressure at the inlet of the line leading to the consumer can be maintained by venting gas from the main line of the unit to the bypass pipe.

The proposed system - energy refrigeration complex - works as follows.

High pressure gas with an open shut-off element 1, having passed the purification filter 2, enters a pressure regulator 9, which maintains a predetermined constant pressure at the gas inlet to the first unit. To the gearbox 9, the gas stream enters through the shutoff member 7 via any of the three pipelines connected to the supply pipe at points A, B and C.

At a moderately low temperature of the gas or in the case when an intensive cooling mode is required in external refrigeration devices, gas to the reducer 9 comes from point "A" of the supply pipe.

At a very low gas temperature or when the need for cold is less than the available refrigerating capacity, the gas to the reducer 9 comes from point "B" of the supply pipe, passing through a heat exchanger where the gas is heated.

In a situation where gas is required to be sent to the bypass pipe 23, the gas flow to the gearbox 9 enters through a block of throttle valves 4, behind which the gas has significantly lower pressure and temperature than the gas supplied to the gearbox 9 from points "A" and " In ", which allows you to work in an emergency mode.

In a normal situation, the gas, having passed the gearbox 9 and the shut-off-regulating body 10, enters through the throttle batcher 11 of the power drive into the first turbo-expander 12 of the energy-refrigerating unit, where the gas expands and the shaft of the electric generator 14 is rotated. At the output of the turbo-expander 12, for example, using a thermocouple, lowering the temperature of the gas stream and, depending on its value, the gas through the check valve 15 and the condensate collector 21 is directed either to the heat exchanger 16, or if the temperature decrease is insufficient for estvleniya desired mode of refrigerating chambers, the gas stream is introduced into the second expansion turbine 12 to implement the next stage of gas expansion. For this, in the first case, the closure member 20 is closed and the organ 18 is opened, and in the second case, vice versa, while the shutoff members 24 and 25 remain open.

In order to direct the gas flow bypassing the turbo expander 12, the automation system closes the shut-off element 10 located in front of it, opens the organs 18 and 25, closes the organs 24, 26 and 27. In this case, the gas flow enters the first heat exchanger 16, and from it to the second stage of gas expansion through the open shutoff member 25.

In order for the flow to be directed directly to the second stage of gas expansion, bypassing the first heat exchanger 16, the automation system additionally closes the shut-off element 18.

Finally, if it is necessary to direct the flow to bypass the second turbo expander 12, the automation system closes the shut-off element 25 and opens the shut-off element 27, as a result of which the gas, bypassing the turbo-expander 12 of the second expansion stage, is directed to the next heat exchangers 16 or, bypassing them, to the turbo-expander 12 of the next expansion stages, as was the case for a gas expansion stage, etc.

In the process of operation of each energy-refrigerating unit, the rotor shaft speed controller 13 (independently or combined with the throttle batcher 11) of the turbo expander 12 through a mechanical connection acts on the gas throttle batcher 11 in such a way that the gas flow rate is regulated by the gas flow rate to maintain the rotor rotor 12 rotor speed.

Energy refrigeration unit

The energy-refrigerating unit (Fig. 3) contains a housing-chamber (capsule) 28, in which an electric generator 30 is installed on the spars - foundation 29 and an expansion turbine (turboexpander) 31, the shaft of which is connected to the electric generator shaft using a coupling 32. Cables from the electric generator 30 are output through the shell of the capsule 28 using current leads 34, consisting of a metal casing, boards of electrically insulating material and embedded in them conductive rods, as well as sealing elements. High pressure gas is supplied to the turbine expander 31 from the manifold 35 via pipelines 36, and to the throttle-metering device 38 is supplied via a separate pipeline 37 with a controlled shut-off element 39, gas is supplied to the manifold 35 through a pipeline also equipped with a controlled shut-off element 40. Pipeline 37, through which gas is supplied to the shut-off element 39, is connected to the gas supply pipe to a controlled shut-off element 40. The control units of the shut-off bodies 39 and 40 are electrically connected to the electronic unit - automation system 49, 30 The hot one also includes the unit protection unit, and when choosing the pneumatic-electric embodiment of the shut-off elements 39 and 40, they are still connected by impulse tubes to the gas supply pipe before entering the shut-off element 40. Gas from the unit capsule 38 is discharged into the pipeline through the pipe 41. In case of emergency, the protection unit , which is contained in the automation system 49, provides pulses for unloading the electric generator 30 and the simultaneous emergency (less than one second) closing of the locking elements 39 and 40. Another version of the gas supply system of the unit, cat The latter is used at higher gas pressures, it provides for the regulation of the total amount of gas that is supplied to the turboexpander 31 using one or more throttle batchers 38, which are connected by their inlets via pipelines to the manifold 35 without installing a shut-off element 39.

The third embodiment of a system for supplying high pressure gas to a turboexpander 31 includes a voltage reduction unit 42, which is connected to the power grid on the one hand and the generator exciter on the other, and also block 43 (contactor), which connects the generator to the power supply and a controlled locking device 40, through which high-pressure gas is supplied to the manifold 35 of the unit, pipelines that connect this manifold 35 to the turbine expander 31.

Power drive with a shovel machine - a turboexpander is an integral part of an energy refrigeration unit.

The power drive includes a housing 44, one of the above systems for supplying gas to the nozzle groups 47 of the blade machine 31, a rotor 45 with blades, which is mounted on the shaft 46, a bearing, a gas throttle batcher 38 (one or more), which is connected by a pipe with nozzles 47 , a system for regulating and maintaining the rotor speed 45, which includes a gas supply regulator 48 through the metering throttle 38 using mechanical or electromagnetic coupling, an automation system electronic unit 49 — a signal converter, an induction frequency sensor 50 niya and modulator 51.

Energy-refrigerating unit with an energy drive in the form of a spatula machine works as follows. High-pressure gas enters the controlled shut-off devices 39 and 40. When the unit is started by an impulse from the automation system (Start button), the shut-off element 39 is opened, and the gas through the throttle batcher 38, controlled by the rotor speed controller 48, enters the nozzle group 47 Passing through the nozzle 47, the gas expands, its pressure decreases, and the speed increases, gas jets act on the blades of the rotor 45 with high speed and thereby rotate the shaft 46, and this shaft, in turn, drives the driven shaft of the electric generator torus 30 through the coupling 32. Depending on the parameters of the gas stream that comes from the high pressure source, all or part of the groups of nozzles 47 are included in the operation to achieve the rated power. A feature of this unit is that its efficiency does not depend on the operating power in the range from 20 to 100%, but only on the degree of expansion of the gas in the expander 31. The throttle batcher 38 is controlled by a regulator 48, to which a signal converter is supplied from the electronic unit 49 an electronic current, the magnitude of which, and consequently its effect on the cross-section in the throttle batcher 38, is changed by a weak current pulse from the induction sensor 50 interacting with the modulator 51. When starting after the shaft 46 reaches of the rotational speed, the sensor 50 begins to supply electric pulses to the electronic unit 49 of the automation system, which converts them and compares them with the setpoint to ensure the nominal rotational speed of the shaft 46. The presence of a discrepancy between the actual and nominal rotational speeds of the shaft 46 determines the amount of current supplied to the regulator 48, which, respectively increases or decreases the gas cross section in the throttle batcher 38 until the nominal speed of the shaft 46 is established, and then the system is regulated Iya (from the sensor 50 to the throttle metering device 38) maintains a constant nominal idle speed of the turbo expander with an electric generator 30. Next, a current frequency synchronization unit 52 of the electric generator 30 is turned on, which compares the current frequency of the generator with the frequency of the current in the external power supply, and then, acting through unit 49 to the regulator 48, which is connected to the choke metering device 38, and to the excitation system of the electric generator 30, adjusts the parameters (frequency and voltage) of the unit current to the network and puts it into synchronism with switching on m of the minimum load of the electric generator 30 through the contactor 43, since the throttle batcher 38 has a limited flow area. After that, an external impulse (manually or using an automation system) is applied to open the main valve 40 for supplying gas to the expander 12, which opens smoothly (within 30-50 s), gradually increasing the load on the generator 30 to a maximum value, and the electricity generated by the unit through cables through sealed current leads 34, through a contactor 43 and a disconnecting cell and other devices is transmitted to an external power supply. When the unit stops (Stop), the load is removed from the generator 30 and at the same time the controlled locking elements 39, 40 are closed and the metering choke 38 is closed. When the voltage, frequency and current strength of the generator, as well as the temperature of the bearings, etc. outside the set limits, pulses are sent to the protection block 53, which, in turn, gives a pulse to the emergency stop of the unit according to the same algorithm as when the Stop button was pressed.

In the second version of the gas supply system and regulation of the unit’s operating mode, when higher pressure gas is supplied to it, and it is possible to pass the entire gas stream through, for example, two or three metering chokes 38, controlled shut-off bodies 39 are not installed in front of them, metering choke 38 by pipelines it connects directly to the manifold 35, to which gas is supplied through the shut-off element 40. Starting and loading with this design of the unit, its stopping and protection are carried out according to the same algorithm as described above. In the third embodiment of the unit, when there is no controlled shut-off element 39, a throttle batcher 38 with a regulator 48, an electronic block 49 a signal converter, a synchronization block 58, induction sensors 50, a modulator 51, and gas from the manifold 35 is simultaneously supplied to all working groups of nozzles, the operation of the energy refrigeration unit is as follows. When starting the unit, the controlled shut-off element 40 is closed, the generator 30 is connected to the external power supply using the Start button 42 and the rotor of the electric generator 30 is rotated by current (the electric generator is started as an electric motor together with the turbine of the expander), it accelerates to a sub-synchronous speed and then the generator (as a synchronous motor with a short-circuited rotor) enters into synchronism with an external power supply network. After that, the power supply of the electric generator 30 with the current from the network is switched to full voltage by turning off the unit 42, and a pulse is applied to open the controlled locking element 40, which opens smoothly (within 30-50 s). At the initial moment, when the gas leaves the nozzles 47 and acts on the blades of the turbine expander rotor 45, the current consumed by the electric generator 30 from the external network decreases to zero, and then the current starts to flow from the electric generator 30 to the external electric network and the load on the electric generator 30 increases to the nominal (as much as possible). The unit is stopped and protected by simultaneously removing the load from the generator 30 and stopping the gas from entering the turbo expander 12 by urgently (within 0.5 s) closing the controlled shut-off element 40, which has an additional device (unit) 54 to guarantee closure, which is still activated and when the system is de-energized, for example, a short circuit in the external network or a power failure to the automation system of the unit.

Gas fridge

The gas refrigerator (Fig. 4) contains the actual refrigerating chambers 55, in which heat exchangers 56 are located with fans 64 that take in heated air, blow it through heat exchangers, and this ensures cooling and air circulation in the chamber.

The gas inlet into the internal cavity of the first in-line gas heat exchanger 56 (first chamber) is connected by a pipe equipped with a regulating-locking body 57 with a collector into which cold gas is supplied from energy-refrigerating units, and the output of the heat exchanger 56 can be connected by a pipe to the input of a series-connected heat exchanger, which is located in the next (second) refrigerator, where a higher air temperature is required than in the first refrigerator. Ultimately, the gas outlet from the heat exchangers of the refrigerator is connected by pipelines to the gas pipeline through which gas is supplied to the consumer.

Figure 4 shows only two refrigeration chambers 55 (first and second) of the refrigerator (separated by a transport corridor) in which heat exchangers 56 are located. The input of the heat exchanger 56, which is located in the first chamber 55, is connected to the collector by a pipeline with a regulating shut-off member 57, which receives cold gas from energy-refrigerating units, and their outlet is connected by a pipe equipped with a shut-off element 58 to the inlet of the heat exchanger 56, which is located in the second chamber, and the outlet is connected by a pipe with a shut-off element 79 to the pipe gas supply rovodom consumer. After the controlled regulatory body 57, the gas pipeline to the entrance to the first chamber 55 is equipped with a discharge candle with a locking body 59, and in the transport corridor of the refrigerator (up to the locking body 58 along the gas), a pipeline equipped with a locking body 60 is connected to the gas exhaust pipe from the heat exchangers 56 and the connection unit 61 of the hot air source for thawing the heat exchangers 56 at certain intervals. The heat exchanger located in the second refrigerating chamber is equipped with the same pipeline and a discharge candle. In some cases, additional cold can be supplied to the first refrigerating chamber 55 from an autonomous refrigeration producer 62, for example, from one that is installed on refrigerated trucks. Such an assembly is connected by air ducts 63, 72 to the chamber 55, through which it takes air from the refrigerating chamber 55 and after cooling returns air back to the chamber 55. At the upper points of the refrigerating chambers 55, methane concentration sensors 68 are installed, which are connected through an electronic converter 69 to an automatic control system 66 acting on the regulating shut-off member 57. The electric motors of the fans 64 of the heat exchangers 56 are connected through the control unit 65 to the automation system 66, which provides them with Operation, mode control and stop. The refrigeration chambers 55 are equipped with remote sensors 67, which are electrically connected to the automation system 66, which uses their pulses to act on the electric motor control unit 65 of the heat exchanger fans 64 to provide a predetermined average air temperature in each chamber. In addition, the temperature sensors 67 of the first chamber 55 also through the automation system act on the stand-alone refrigerant 62.

Gas refrigerator operates as follows. When a power unit operates with energy-refrigerating units, electricity is generated due to the expansion of gas, which is cooled, the cooling temperature is determined by the degree of gas pressure decrease and turboexpander efficiency. This chilled gas, through a controlled regulating shut-off element 57, enters heat exchangers 56 located in refrigerating chambers 55, in which air is circulated, driven by fans 64 through the heat-exchanging surfaces of apparatus 56, and thus cold is taken from them to cool chambers 55, and the gas temperature the output of the heat exchangers 56 is accordingly increased. In a gas refrigerator, one-, two-stage and three-stage selection of cold from incoming cold gas can be carried out. In the first chamber 55 (first stage), the system maintains the average air temperature in the range of minus 18-20 ° С, and in the second chamber, where the second stage of cold extraction from gas is carried out, the system maintains the average air temperature in the range of minus 7-9 ° C, and in the third stage - within minus 3 - plus 2 ° C. These modes are implemented as follows: in the first chamber, heat exchangers 56 are designed for maximum cold volume, i.e. their heat-exchange surface must be such as to ensure that the specified temperature of the air in the chamber is maintained at the highest temperature of the gas coming from energy-refrigerating units. The regulation of the volume of gas entering the heat exchanger 56 of the first chamber is carried out by means of a regulating-locking body 57, the opening mode of which is controlled by the automation system 66 according to a given level of air temperature in the chamber, by the pulse received from temperature sensors 67. In the second chamber, the same heat exchanger is installed as in the first chamber 55. The heat exchanger placed in the second chamber receives gas through the pipeline with the shut-off element 58 open, which has already passed through the heat exchanger 56 located in the first chamber, and has given part of its cold and its temperature accordingly increased. The lowest air temperature in the second chamber should be ensured at the highest temperature of the gas entering its heat exchanger, and the highest air temperature in the second chamber should be achieved by changing the operating modes of the fans 64 of the heat exchanger 56, driving air through them from the chamber the purpose of cooling it.

Regulation can be carried out, for example, by changing the speed of the fans 64 and turning off the fans. The mode of operation of the fans 64 is changed in order to maintain a predetermined air temperature in the chamber using an automation system 66, which receives a pulse from the air temperature sensors 67 in the chamber.

After the cold gas returns to the air of the second chamber, gas from the heat exchangers enters through the open shutoff member 70 into the gas supply line to the consumer. At the same time, its temperature is acceptable for normal and safe operation of technical means of transport and gas use by the consumer. Based on these conditions and ensuring the maximum use of the generated cold in the gas refrigerator, it is envisaged that cold gas will pass through the heat exchangers of the chambers first, in which the gas temperature should be kept within minus 18-20 ° С, and then through the heat exchangers of the chambers connected to them in series, where you want to ensure the maintenance of a higher temperature, for example, minus 7-9 ° C. With significant volumes of the refrigerator, if there are chambers with different controlled air temperatures, it allows you to increase the range of products that can be taken for storage, and therefore to ensure the most complete load of the refrigerator and the efficient use of the produced cold.

According to this invention, the design of heat exchangers and their pipelines is envisaged to be performed without detachable connections within the premises of refrigerators, i.e. cold rooms and transport corridor. This ensures the safety of using cold natural gas as a refrigerant. To ensure safety, in addition, it is planned to install methane concentration sensors 68 at the upper points of the chambers 55 and in the corridor (inside), which transmit their pulses through block 69 at a concentration of up to 1% methane in air (explosive mixture of methane with air from 5 to 15 %) to the automation system 66, which, in turn, generates and sends pulses to close the regulating and locking element 57. Next, the locking elements 58 and 70 are closed and the hatch 71 and the locking elements 59 on the vent gas candles are opened. After the gas is discharged from the system, a gas leak is searched for and eliminated. When the camera is put into operation, the locking elements 57, 58, 70 are opened, and the locking body 59 and the hatch 71 are closed.

According to the operating conditions of the refrigerating chambers 55, the snow freezes on the heat-transmitting surfaces of the apparatus 56 and needs to be thawed and thawed at certain time intervals. This operation, for example, for the first camera 55 is performed in the following order. The heat exchanger 56 is disconnected from the gas system by shutting off the shutoff members 57 and 58, and the gas is discharged onto the candle through the open shutoff member 59. Then, the shutoff member 60 is opened in the pipeline, and a source of hot air, which passes through the pipelines, is connected to the assembly 61 cavity of the heat exchanger 56 and through the candle with the open shut-off body 59 goes into the atmosphere. This continues until the heat transfer surfaces of the heat exchanger 56 are cleared of frozen snow. After that, the locking bodies 59 and 72 are closed, the locking bodies 57 and 58 are opened and the camera is thus turned on. The same operations are performed when defrosting the heat exchanger of the second chamber and other subsequent chambers. The chambers provide the necessary conditions for the flow of water generated during the defrosting of heat exchangers.

Ice maker with ice storage

The ice maker (Fig. 5) contains a heat-insulated chamber 73, a device 74 for supplying water into the chamber in the form of droplets of adjustable size, a heat exchanger 75 with a fan 76, the internal cavity of the apparatus is connected by a pipeline equipped with a regulating and shut-off element 77 with a source of cold gas, and the output is with a gas supply pipe to the consumer through the shut-off element 94. The heat exchanger 75 is placed in a heat-insulated channel 78, through which air from the freezer chamber 73 enters the fan 76, which blows it through the outer surface s and the heat exchanger 75, after the air has cooled after passing through this apparatus, it returns to the chamber 73 through the channel 79 through inlet device 80, which can adjust the direction of air flow. In the lower part of the chamber, one or more channels tapering downward and an ice receiver 81 of ice, with a balancer 85, mounted on an axis 82, fixed in the initial position by a device 83, for example, spring, electromagnetic or other type. The inner surfaces of the chamber of the ice maker 73 and the ice storage are covered with a water-non-wettable material, for example Teflon, etc. Under the ice store 81, a conveyor 84 is placed, which partially goes into the ice storage room (not shown). In addition, a system of conveyors is placed in the ice storage, the number and dimensions of which are determined based on the area and configuration of the ice storage. The ice storage facility can also be equipped with shelves for storing ice briquettes and a block for preparing commercial ice (ice crusher). The walls and roof of the ice storage are made of insulating materials.

A device 74 for supplying droplet water to the chamber is connected by a pipeline equipped with a regulating-shutoff body 89 to a water-gas heat exchanger 87, the inlet of which is connected to a cold gas source by a pipe equipped with a regulating-shutter 88. The gas outlet from the heat exchanger 87 by a pipe equipped with a shutoff body 90, connected to the gas supply line to the consumer.

A temperature sensor 91 is installed in the chamber 73, which is electrically connected to the automation system 92, which provides control of the regulating-locking member 77 and the operation mode of the fan 76.

A temperature sensor 93 is installed in the droplet forming device 74, which is electrically connected to the automation system 92, which controls the shut-off and regulating organs 88 and 89.

Ice machine with ice storage work as follows.

The essence of the method of ice formation is that drops of water pre-cooled to a temperature of 0-2 ° C in the heat exchanger 87, which fall out of the nozzles of the device 74, fall into the oncoming flow of cold (temperature to minus 30 ° C) air, which is pumped into the chamber by a fan 76 of the heat exchanger 75 through the channel 79 and the guide pipes 80, which inhibits the drop of droplets inside the chamber and this increases the residence time of the droplets in cooled air, which is sufficient to freeze them, and in the lower tapering It is the camera 73 and tank 81 falls ice ice balls.

The operation of the ice maker begins with cooling the air that is in the chamber 73. To do this, open the locking elements 90 and 94, then using the Start button, using the automation system 92, simultaneously turns on the fan 76 and the control and locking element 77, through which cold gas from the source is supplied to the heat exchangers 75 and 87, while the temperature sensor 91 monitors a decrease in air temperature inside the chamber 73. When the desired air temperature is reached from the sensor 91, an impulse is supplied to the automation system 99, I open the shut-off bodies 88 and 89 tsya. In this case, cold gas and water enter the heat exchanger 87, in which the water is cooled to a temperature of 0 - minus 2 ° C, and then the water flows through the pipe into the droplet forming device 74, at the outlet of the nozzles of which droplets are formed that fall into the cold upward air stream . When there is sufficient time in this stream, water droplets turn (as the chambers 73 move downward) into ice balls, which fall into the accumulator 81 mounted on axis 82. The ice accumulator 81 has an asymmetric profile with respect to axis 83 and when it is filled with ice balls a vertical force A arises to the upper level, the tilting moment from which is greater than the counterbalancing moment of the counterweight 85, which leads to a certain inclination of the drive 81 in the tilting direction, and the device 83, which releases ice accumulator 81, it capsizes around the axis 82, and the ice briquette hits the conveyor 84, and the ice accumulator 81 returns to its original position under the influence of the moment, which creates a counterweight 85 and is fixed by the device 83. Then this process is repeated. Conveyor 84 moves the ice briquette to the ice storage distributor, from which, using conveyors and elevators, the ice briquettes are transported to the places of their storage.

When preparing marketable ice using conventional technology, it is cut into pieces and then passed through an appropriately configured ice crusher, after which marketable ice is loaded onto a vehicle using a conveyor and sent to its intended destination. If it is not possible to obtain the required temperature for the heat exchanger 75, it is reduced by connecting to the ice machine an autonomous traditional low-power refrigeration producer, similarly to the chambers of a gas refrigerator.

The requirements for the design of the heat exchanger, pipelines and the location of the locking elements in terms of exclusion of detachable joints remain the same as for a gas refrigerator. The process of thawing the heat exchange surface of the apparatus is carried out in the same way and using the same means as described in relation to a gas refrigerator.

The above material allows us to conclude that the proposed technical solution in the amount of six inventions (method and five devices) overcomes a number of problems that stand in the way of successful application of technology to increase the efficiency of natural gas use by utilizing the source pressure differential. All this indicates the solution of the problem of the invention.

Industrial applicability

The present invention can be applied in means of generating electricity and in cooling systems through the use of technological pressure differences of natural gas, primarily in gas distribution systems, as well as in places of gas production and at compressor stations.

Claims (31)

1. A method of preparing natural gas for supplying a consumer with the integrated use of natural gas energy by expanding natural gas in at least one expander of an electro-refrigerating unit (ECA), diverting the mechanical energy of each expander to drive an electric generator of a corresponding ECA, and passing cooled from ECA gas expander before being supplied to the consumer through at least one refrigerator heat exchanger, characterized in that a refrigerator with cameras is used, in each of which a heat exchanger is placed, cold gas is passed sequentially through the heat exchangers of the refrigerator chambers, and part of the cold gas is passed into an ice generator heat exchanger connected to the output of the corresponding ECA or to a collector connected to the output of each ECA to obtain a gas temperature at the output of the ice machine, ensuring its use by the consumer . 2. The method according to claim 1, characterized in that the degree of expansion of the gas in each expander is selected from the condition of ensuring the specified gas temperature at the inlet to the heat exchangers of the refrigerator and the ice maker. 3. The method according to claim 1, characterized in that when the degree of expansion of the gas in the expander or expanders is insufficient to provide a predetermined gas temperature at the inlet to the refrigerator and / or the ice maker, an independent refrigeration maker is connected to the refrigerator and / or the ice maker, respectively. 4. The method according to claim 1, characterized in that the system comprising at least one of said expanders, an electric generator, a refrigerator and an ice maker is connected to a natural gas source and to a gas supply pipe to a consumer in parallel with a gas reduction station (GDS) ) to reduce the load on it and maintain the required parameters of the gas supplied to the consumer. 5. The method according to claim 1, characterized in that when using more than one expander and when the amount of gas passing through the GDS exceeds the amount of gas passing through the specified system, a part of the gas is bypassed past the system, the gas temperature is measured after mixing the gas flows and when the temperature decreases beyond the permissible level, the proportion of gas passing through the system is reduced by shutting off part of the expanders. 6. A system for preparing natural gas for supplying a consumer with the integrated use of natural gas energy, comprising at least one energy refrigerating unit (ECA), each of which includes an expander and an electric generator connected to its shaft, at least one gas refrigerator, the heat exchanger of which is connected to the outlet of at least one ECA, and the gas supply pipe to the consumer, characterized in that the gas refrigerator contains chambers, in each of which a heat exchanger is placed, heat exchangers are connected each other in series, and the output of the heat exchangers is connected to the pipeline for supplying gas to the consumer, and the system is equipped with at least one ice generator, the heat exchanger of which is connected to the output of the corresponding ECA or to a collector connected to the output of each ECA, and to the gas supply pipeline to the consumer. 7. An energy-refrigerating unit, comprising a sealed chamber with an outlet pipe, a turboexpander installed in it and an electric generator connected to its shaft, a turboexpander shaft speed sensor, a throttle-metering device connected to the gas supply pipe to supply gas to the turbine expander nozzles, a gas flow regulator connected thereto and an electronic unit associated with said sensor and controller, characterized in that the turbo-expander nozzles are divided into two or more groups, one group of nozzles is connected to the base pipe yes gas through the specified metering throttle, and another or others through the manifold or through an additional metering choke or metering choke. 8. The assembly according to claim 7, characterized in that a shutoff member controlled by an automation system is installed on the gas supply line to the turbine expander with a smooth opening operation when the generator is loaded and quickly closed by a signal from the automation system, formed by an external switch on or by a protection unit deviation of the operating parameters of the unit and processes beyond the specified limits with the possibility of simultaneously removing the load from the generator and closing the shut-off element. 9. The unit according to claim 7, characterized in that the turboexpander has a strength calculated for the highest accepted level of gas pressure, and the chamber has a strength calculated at a pressure less than the highest accepted by the magnitude of the degree of expansion of the gas in the turboexpander. 10. The unit according to claim 7, characterized in that a gas reducer is installed on the gas supply line to the turbo-expander to maintain its pressure no higher than the level for which the strength of the turbo-expander is calculated, and safety valves are installed on the outlet pipe connected to the chamber the possibility of triggering when the gas pressure in the chamber is increased above the permissible level for which the strength of the chamber is calculated, and their total flow area is selected greater than the cross section of the nozzles of the turbo expander. 11. The assembly according to claim 7, characterized in that the chamber has dimensions determined on the basis of the dimensions of the generator of the highest power in the used power range, and the turboexpander has the dimensions of the flow part and power calculated from the condition that the generator reaches its rated power at the lowest specified gas pressure at the entrance to the turbo expander. 12. The unit according to claim 8, characterized in that at a minimum, but sufficient for the turbo-expander to develop a given gas flow power from the source, the throttle-dispenser is connected to one group of nozzles and to a gas supply pipe to the turbo-expander equipped with said shut-off element, and the unit is equipped with a collector connected to the other groups of nozzles of the turbo-expander and with the specified pipeline for supplying gas to the turbo-expander for starting, putting the electric generator in synchronism with the external network and developing power 5-10% of the nominal when supplying gas through a metering throttle for full loading of the electric generator with additional gas supply through the collector. 13. The unit according to claim 10, characterized in that at high source gas pressures two or more metering orifice chokes connected to respective groups of nozzles are connected to a manifold connected to a gas supply line to a turbo-expander to provide gas supply through the metering choke , when regulating the gas supply to the nozzles, both during start-up and commissioning of the electric generator in synchronism with the power supply network, and at its rated load and other operating modes of the unit. 14. The assembly according to claim 7, characterized in that the flow part of the turboexpander has parameters, namely, the number and dimensions of the groups of nozzles of pipelines included in it, connected to the exits of the manifold or with a throttle batcher, calculated from the condition of ensuring optimal efficiency when changing the gas pressure at its entrance 4-5 times, gas consumption 4-6 times and turbo expander power 3-4 times. 15. The unit according to claim 7, characterized in that the generator is made with the power to use it when starting up the unit as an electric motor and untwisting its rotor and turbine expander shaft when voltage is applied to it from an external power supply to a frequency synchronous with the power supply and with the possibility of transition after that and after supplying gas to the nozzles of the turboexpander from the engine mode to the generator mode when the power consumed by the unit and the power it generates are equal and the nominal mode is reached. 16. An energy drive with a spatula machine, comprising a housing mounted on the rotor shaft with rotor blades mounted thereon, mounted on the nozzle housing and directed to the rotor blades, a throttle batcher and a rotor shaft speed sensor connected to a gas supply regulator through a throttle batcher, characterized in that the nozzles are divided into several groups, one group of nozzles is connected to the gas supply pipe through the specified metering throttle, and the rest through a manifold connected to the shutoff body. 17. The power drive according to clause 16, characterized in that the number of nozzles connected to the gas supply pipe during operation of the power drive is determined based on the conditions for achieving the rated power with maximum efficiency at the lowest pressure of the source gas. 18. The drive according to claim 16, characterized in that the degree of expansion of the gas is selected based on a given gas temperature at the output of the drive at the highest temperature of the gas entering the drive from the source. 19. A gas refrigerator containing heat-insulated chambers with a lockable opening and heat exchangers, characterized in that a heat exchanger and a fan are placed in each chamber, to ensure storage of products at different temperatures, the heat exchangers are connected in series and shut-off regulating organs are installed on the pipelines for supplying cold gas to each heat exchanger with the possibility of maintaining the lowest air temperature and a successively increasing temperature in the first cold gas chamber air in subsequent chambers. 20. The refrigerator according to claim 19, characterized in that each chamber is equipped with an air temperature control system associated with temperature sensors located in the chamber, with a shut-off regulating body and with a fan with the ability to change the supply of cold gas to the heat exchanger and / or the fan speed in depending on the set and actual air temperatures in the chambers. 21. The refrigerator according to claim 19, characterized in that at an insufficiently low temperature of the supplied cold gas, at least one chamber is connected to an autonomous refrigeration producer with the possibility of taking part of the air from the chamber, cooling it and returning it back to the chamber to maintain a given temperature. 22. The refrigerator according to claim 19, characterized in that for periodically thawing the heat exchangers, the outlet pipe of each heat exchanger is connected through a shut-off element to a hot air blower attachment unit, and a discharge candle is connected to the heat exchanger inlet through the shut-off element to exit the gas exchanger first, and then hot air. 23. The refrigerator according to claim 19, characterized in that methane concentration sensors are installed at the upper points of each chamber, which are connected through a signal converter-amplifier to an automation and protection system connected to a shut-off element installed on the gas supply pipe to the heat exchanger, and with exhaust ventilation system. 24. The refrigerator according to claim 19, characterized in that the heat exchangers and pipelines located inside the chambers are made without detachable connections, and the locking elements are located outside the chambers. 25. An ice maker containing a thermally insulated chamber, in which a droplet former with a means for spraying water is placed, a fan, a heat exchanger and an ice receiving device located in the lower part of the chamber, characterized in that the heat exchanger is placed in the said thermally insulated channel and connected to the supply pipelines and discharge of cold gas with locking elements, the specified channel is connected by its inlet to the upper part of the chamber, and the outlet - with holes in the side walls of the chamber to enter Amer chilled air. 26. Ice maker according A.25, characterized in that the droplet is connected to another heat exchanger for supplying water cooled with cold gas. 27. The ice maker according to claim 25, wherein the ice receiving device is an ice storage device in the form of a container located in the lower part of the chamber with inclined walls and a balancer mounted on an axis and connected to a fixing device with the possibility of unlocking and tipping the storage device when filling its ice due to the asymmetry of the drive and the return of the drive freed from ice to its original position due to the moment from the balancer and fixing the drive. 28. An ice maker according to claim 27, wherein the inner surfaces of the ice maker chamber and the storage tank are coated with a water-wettable material, for example Teflon. 29. The ice maker according to claim 27, characterized in that it is equipped with a conveyor belt and an ice storage located under the drive, in which a transportable distributor is installed for supplying ice briquettes to it from the drive using the conveyor belt, and other belt conveyors for briquette stacking are docked to the distributor ice on the floor of the ice storage on top of each other or on racks. 30. An ice maker according to claim 25, wherein the entrance to the ice storage is combined with the exit for ice from the chamber. 32. An ice maker according to claim 29 or 30, characterized in that an ice crushing unit is installed at the outlet of the ice storage for converting ice briquettes into marketable ice of a given structure.

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