JP6173235B2 - Binary power generator operation method - Google Patents

Description

  The present invention relates to a method for operating a binary power generation apparatus using low-pressure steam as a heat source.

2. Description of the Related Art Conventionally, binary power generators exist that generate power by collecting heat from a low-temperature heat source such as exhaust steam discharged from a factory. This binary power generator uses an organic compound having a low boiling point instead of water as a working medium, and can generate power even with a low-temperature heat source compared to a power generator using a normal steam turbine. Yes.
In a power generation device using steam as a heat source, such as the binary power generation device described above, steam may condense inside the evaporator and drain (drainage) may be generated, and the drain accumulated in the evaporator is forcibly evaporated. In general, drain discharge means for discharging to the outside of the vessel is provided.

For example, in Patent Document 1, a switching valve (negative pressure / positive pressure switching valve) is provided in a steam pipe through which steam that has passed through a heat exchanger flows, and when the pressure of the steam applied to the switching valve is positive pressure. An air heating apparatus is disclosed that includes drain discharge means for sending steam to the steam trap and for sending the drain to the condensate recovery means when the pressure of the steam applied to the switching valve is negative.
Further, in Patent Document 2, a steam supply pipe that supplies steam to an evaporator (heat exchanger) is provided with a steam ejector that generates suction force by the action of steam flowing through the steam supply pipe. There is disclosed a heat exchanger provided with a drain discharge means for convection of steam in a heat exchange container by sucking condensate (drain) stored in a liquid pumping member into a suction chamber of a steam ejector.

JP 2004-163050 A Japanese Patent No. 4594270

  Incidentally, high-pressure steam of about 0.2 to 0.8 MPaG is generally used for steam used for power generation and the like. Among exhaust steam discharged from factories and the like, there is low-pressure steam of 0.2 MPaG or less, but such low-pressure steam is often discarded without being reused. However, the steam has a large latent heat in the working medium, and the latent heat that can be used for power generation remains in the low-pressure steam. That is, even low-pressure steam can be reused and used for power generation.

  However, although the low-pressure steam has a sufficient latent heat, it is only a slightly higher pressure and temperature than the saturated steam. Therefore, if the pressure or temperature of the steam supplied to the evaporator fluctuates even a little, the steam is likely to condense inside the evaporator, and the drain (condensed water) tends to accumulate inside the evaporator. If a large amount of this drain is generated inside the evaporator, the steam pipe is blocked, the heat exchange capacity of the evaporator is greatly reduced, and the power generation of the binary power generator becomes unstable. Therefore, when stable power generation is performed with a binary power generation device using the low-pressure steam described above, it is immediately detected that the drain has accumulated inside the evaporator, and the drain blocked by the steam pipe is externally connected. It becomes more important to provide a means for efficiently discharging.

  However, in the drain discharge means of Patent Document 1 and Patent Document 2 described above, it is impossible to accurately detect that the drain has accumulated inside the evaporator, even though the drain can be forcibly discharged. The blockage of the steam piping due to the drain cannot be quickly resolved, and the above-described problem of the binary power generation apparatus using the low-pressure steam has not been solved.

  The present invention has been made in view of the above-described problems, and can quickly detect and eliminate the blockage of the evaporator by the drain, and can stably generate power even when low-pressure steam is reused. An object of the present invention is to provide a method for operating a binary power generator that can be used.

In order to solve the above problems, the operation method of the binary power generation apparatus of the present invention employs the following technical means.
That is, the operation method of the binary power generation device according to the present invention includes an evaporator that evaporates a working medium using steam having a pressure of 0.2 MPaG or less as a heat source, and a rotational driving force by expanding a gaseous working medium evaporated by the evaporator. Operation of a binary power generator comprising: an expander that generates a gas; a condenser that condenses the working medium of the gas expanded in the expander into a liquid; and a circulation pump that circulates the working medium from the condenser toward the evaporator The method includes an inlet-side steam pressure gauge that measures the inlet-side steam pressure of the evaporator, an outlet-side steam pressure gauge that measures the outlet-side steam pressure of the evaporator, and accumulated in the evaporator. and forcible drain discharge means for forcibly discharging the drain to the outside of the steam pipe, keep the provided wherein the exit-side steam pressure P ₃ measured by the steam pressure gauge, the steam pressure P measured by the entry-side steam pressure gauge It is larger than ₁ If, and wherein the actuating said forced drain discharge means.

Incidentally, preferably, the the exit side steam pressure P ₃ measured by the steam pressure gauge, if it becomes less than the vapor pressure P ₁ measured by the entry-side steam pressure gauge, when stopping the forcible drain discharge means Good.
Preferably, the forced drain discharge means forcibly discharges the vapor drain to the outside of the evaporator by using the vapor pressure on the inlet side of the evaporator as a driving force.

Preferably, the forced drain discharge means includes a first drain pipe having a large pressure loss during drain discharge and a second drain pipe having a pressure loss during drain discharge smaller than the first drain pipe. wherein the exit-side steam pressure P ₃ measured by the steam pressure gauge, if it becomes larger than the vapor pressure P ₁ measured by the entry-side steam pressure gauge, with the second drain pipe, to discharge the drain, wherein the exit-side steam pressure P ₃ measured by the steam pressure gauge, if it becomes less than the vapor pressure P ₁ measured by the entry-side steam pressure gauge, with the first drain pipe, it is preferable to discharge the drain .

  Preferably, an outlet medium pressure gauge for measuring the pressure of the working medium and an outlet medium thermometer for measuring the temperature of the working medium are provided on the outlet side of the evaporator, and the outlet side Based on the steam pressure measured by the medium pressure gauge and the steam temperature measured by the outlet medium thermometer, the degree of superheat of the working medium on the outlet side of the evaporator is calculated, and the calculated degree of superheat is calculated in advance. It is preferable to control the circulation amount and pressure of the working medium by the circulation pump so as to be within the allowable range of the degree of superheat.

  Preferably, the steam pipe located on the outlet side of the evaporator is branched into a drain mainstream pipe and a drain branch pipe, and the drain main stream pipe and the drain branch pipe are arranged at the branch position. And a drain cooling / discharge switching valve for switching to the drain branch pipe, the drain branch pipe is provided with a drain cooling means for cooling the circulating drain, and the drain branch pipe and the drain main stream pipe are arranged downstream of the drain cooling means. The drain merging pipe is joined to form the drain merging pipe, the drain merging pipe is connected to the forced drain discharging means, and the drain merging pipe is further provided with a drain temperature measuring means for measuring the drain temperature, and the drain cooling means A drain cooling water flow rate adjustment valve capable of adjusting the flow rate of the cooling water introduced into the Based on the temperature of the drain measured by the Lane temperature measuring means may be adjusted to the valve opening degree of the drain cooling water flow rate adjustment valve.

  Preferably, a part of the cooling water used for condensing the working medium in the condenser is introduced into the drain cooling means.

  According to the operation method of the binary power generation apparatus of the present invention, the blockage of the evaporator due to the drain can be quickly detected and solved, and stable power generation can be performed even when low-pressure steam is reused.

It is the figure which showed the binary electric power generating apparatus of 1st Embodiment. It is the figure which showed the binary electric power generating apparatus of 2nd Embodiment. It is the figure which showed the binary electric power generating apparatus of 3rd Embodiment. It is the figure which showed the binary electric power generating apparatus of 4th Embodiment. It is the figure which showed the "ON state" and "OFF state" of a drain cooling / discharge switching valve. It is the flowchart which showed the operating method of the binary power generator of 4th Embodiment.

[First Embodiment]
Hereinafter, an embodiment of a binary power generator 1 and an operation method of the binary power generator 1 of the present invention will be described in detail with reference to the drawings.
FIG. 1 schematically shows a binary power generator 1 according to a first embodiment.
As shown in FIG. 1, the binary power generation apparatus 1 includes an evaporator 2 that evaporates a liquid working medium using vapor as a heat source, and an expansion that generates a rotational driving force by expanding a gaseous working medium evaporated by the evaporator 2. And a condenser 4 that condenses the gaseous working medium expanded in the expander 3 into a liquid, and a circulation pump 5 that circulates the working medium from the condenser 4 toward the evaporator 2. The evaporator 2, the expander 3, the condenser 4 and the circulation pump 5 are connected by a closed loop circulation pipe 6 that circulates the working medium, and the working medium passes through the circulation pipe 6 in one direction (evaporator 2 → expansion). Circulating in the order of the machine 3 → the condenser 4 → the circulation pump 5 and returning to the evaporator 2).

Next, the evaporator 2, the expander 3, the condenser 4, and the circulation pump 5 that constitute the binary power generator 1 will be described.
The evaporator 2 is a heat exchanger that performs heat exchange between the steam supplied to the primary side and the working medium supplied to the secondary side, and vaporizes the liquid working medium using the heat of the steam. Is. On the primary side of the evaporator 2, a steam pipe 7 for supplying steam into the evaporator 2 is provided, and steam generated in, for example, hot springs (low-pressure steam described later) is provided through the steam pipe 7. ) Is supplied to the inside of the evaporator 2. Further, a liquid working medium is supplied to the secondary side of the evaporator 2 through the circulation pipe 6 described above, and heat exchange is performed with the steam on the primary side. The working medium heated by heat exchange with the steam on the primary side is transferred toward the condenser 4 through the circulation pipe 6.

The inlet side steam pipe 7 of the evaporator 2 is provided with a pressure reducing valve 8 capable of reducing the steam pressure supplied to the evaporator 2, and the outlet side steam pipe 7 of the evaporator 2 is connected to the evaporator 2. A steam trap 9 (forced drain discharge means) for removing the accumulated drain (condensed water) is provided. The pressure reducing valve 8 and the steam trap 9 will be described in detail later.
The circulation pipe 6 from the evaporator 2 to the expander 3 is provided with a lubrication means 14 for supplying lubricating oil to a turbine or the like used in the expander 3. Lubricating means 14 is provided on a circulation pipe 6 directed from the evaporator 2 to the expander 3, and an oil separator 15 that separates lubricating oil from a working medium flowing through the circulation pipe 6. And a lubricating oil supply pipe 16 for supplying the lubricating oil separated from the oil to the expander 3 (the turbine of the expander 3).

  The expander 3 generates a rotational driving force using the working medium vaporized by the evaporator 2, and is configured by a turbine or the like. The expander 3 is provided with a drive shaft 18 that transmits the rotational driving force obtained by the expander 3 and a generator 13 that generates electric power using the rotational driving force transmitted through the drive shaft 18. Yes. The expander 3 is supplied with lubricating oil via the lubricating oil supply pipe 16 of the above-described lubricating means 14 so that the turbine or the like can be rotated while being sufficiently lubricated with the lubricating oil. . The gaseous working medium that has passed through the expander 3 is sent to the condenser 4 through the circulation pipe 6.

  The condenser 4 performs heat exchange between the cooling water supplied to the primary side and the gaseous working medium supplied to the secondary side to condense (liquefy) the gaseous working medium. . On the primary side of the condenser 4, there are a cooling water pipe 11 that supplies the cooling water cooled by the cooling tower 10 (chiller), and a cooling water pump 12 that distributes the cooling water along the cooling water pipe 11. Is provided. Further, the gas working medium sent from the expander 3 is supplied to the secondary side of the condenser 4 via the circulation pipe 6, and the liquid working medium condensed inside the condenser 4 is supplied to the secondary side of the condenser 4. It can be transferred to the circulation pump 5.

The circulation pump 5 pumps the liquid working medium condensed in the condenser 4 to the evaporator 2 along the circulation pipe 6, and operates such as rotation speed, voltage, or current through an inverter 23 described later. Conditions can be adjusted.
In addition, a preheater 17 that preheats (preheats) the liquid working medium is provided on the circulation pipe 6 from the circulation pump 5 toward the evaporator 2 in order to reduce the load on the evaporator 2. Warm water is supplied to the preheater 17 from the outside, and the liquid working medium can be preheated by exchanging heat with the warm water.

The working medium used in the binary power generation apparatus 1 described above uses an organic compound having a boiling point lower than that of water, such as alternative chlorofluorocarbon or pentane, and performs power generation using heat supplied from steam as a heat source. It is possible.
Further, low-pressure steam having a pressure of 0.2 MPaG or less is used for the steam supplied to the evaporator 2. The steam as the heat source will be described in detail later.

When power is generated by the binary power generator 1 shown in FIG. 1, first, steam (low-pressure steam) is supplied to the primary side of the evaporator 2 and a liquid working medium is led to the secondary side of the evaporator 2. Then, heat exchange is performed between the two in the evaporator 2 to vaporize the working medium.
When the working medium is vaporized in the evaporator 2 in this way, the vaporized working medium is sent to the expander 3 to drive the expander 3. The rotational driving force generated in the expander 3 is sent to the generator 13 via the drive shaft 18 and the generator 13 generates power. On the other hand, the gaseous working medium used to drive the expander 3 is sent to the condenser 4, where heat exchange is performed with the cooling water in the condenser 4, and the gaseous working medium returns to liquid (condensation). ) The liquid working medium condensed in the condenser 4 is pumped by the circulation pump 5, and returns to the evaporator 2 again via the preheater 17. In the preheater 17, the liquid working medium is preheated by the action of hot water supplied from the outside, and the preheated working medium is further heated by the evaporator 2, so that the liquid working medium changes to a gaseous working medium ( Vaporize). In this way, the binary power generation apparatus 1 generates power using the Rankine cycle while circulating the working medium.

  By the way, in the case of the binary power generation apparatus 1 of the present invention, low-pressure steam that is not normally used for power generation, in other words, steam that is normally not used but discarded is used. This low-pressure steam is steam having a pressure lower than the range of 0.2 to 0.8 MPaG generally used for power generation, and is set to a pressure of 0.2 MPaG or less. In the present invention, this low-pressure steam is called “steam” and is distinguished from high-pressure steam of 0.2 to 0.8 MPaG.

  The above-mentioned steam having a pressure of 0.2 MPaG or less is “low pressure” compared to high-pressure steam used for normal power generation, but contains a lot of thermal energy (latent heat) and is sufficiently used for power generation. be able to. However, this low-pressure steam is only a little higher in pressure and temperature than saturated steam, so it easily condenses inside the evaporator and drains (condensed water) inside the evaporator. Tends to accumulate. When the drain is generated inside the evaporator, the steam pipe is blocked, and the heat exchange capacity of the evaporator is greatly reduced, and the power generation of the binary power generation apparatus may become unstable (a stall phenomenon may occur). Therefore, when the low-pressure steam described above is used as a heat source, the drain is likely to be generated inside the evaporator 2, so that the steam trap 9 (forced drain discharge means) is quickly detected by detecting the blockage of the steam pipe 7 by the drain. Need to operate quickly.

  Therefore, in the operation method of the binary power generation device 1 of the present invention, the steam pressure flowing through the steam pipe 7 on the outlet side of the evaporator 2 and the steam pressure flowing through the steam pipe 7 on the inlet side of the evaporator 2 are compared, A configuration is employed in which the steam trap 9 is activated when the steam pressure on the side becomes larger than the steam pressure on the entry side. That is, when the evaporator 2 is blocked by the drain, the vapor pressure on the outlet side of the evaporator 2, which is normally lower than the inlet side of the evaporator 2, becomes higher than the vapor pressure on the inlet side of the evaporator 2. The present inventors are aware. Therefore, if the closure of the steam pipe 7 by the drain can be detected quickly based on the difference in the steam pressure between the inlet side and the outlet side of the evaporator 2, the drain generated by operating the steam trap 9 can be quickly detected. It becomes possible to eliminate.

Specifically, in the binary power generation apparatus 1 described above, an inlet-side steam pressure gauge 19 for measuring the inlet-side steam pressure of the evaporator 2 is disposed in the inlet-side steam pipe 7 of the evaporator 2, and An outlet-side steam pressure gauge 20 that measures the outlet-side steam pressure of the evaporator 2 is disposed in the outlet-side steam pipe 7 of the evaporator 2. Further, the steam pipe 7 on the inlet side of the evaporator 2 is provided with a pressure reducing valve 8 on the steam pipe 7 further on the upstream side of the above-described inlet steam pressure gauge 19, and the steam pipe on the upstream side of the pressure reducing valve 8. 7 is provided with a pressure reducing valve inlet side pressure gauge 21 for measuring the pressure of the steam supplied to the pressure reducing valve 8. The vapor pressure measured by these pressure gauges 19 to 21 is sent to the drain control unit 24. Further, the steam pipe 7 on the outlet side of the evaporator 2 is provided with a steam trap 9 for discharging the drain generated inside the evaporator 2, so that it can be operated by a command from the drain control unit 24. Yes.

Next, the steam trap 9, each pressure gauge, the pressure reducing valve 8, and the drain control unit 24 provided in the binary power generator 1 of the first embodiment will be described in detail.
As shown in FIG. 1, the steam trap 9 of the first embodiment is not shown, but a trap section that stores (traps) a drain that circulates in the vapor pipe 7 on the outlet side of the evaporator 2, and a trap section And a pump unit capable of forcibly discharging the drain trapped in the. This trap unit can store and exclude liquid drains while restricting the passage of gas vapor. For example, only the liquid drain is selected using the difference in specific gravity between the liquid and gas. It is configured to store. The pump unit is forcibly discharging the drain stored in the trap unit to the outside of the evaporator 2 by suction force or the like in response to a command from the drain control unit 24. The pump is driven electrically or by pressure. Etc. are used. The pump unit of the first embodiment uses an electric pump.

The above-described inlet-side steam pressure gauge 19, outlet-side steam pressure gauge 20, and pressure reducing valve inlet-side pressure gauge 21 all measure the pressure of steam flowing through the steam pipe 7. Specifically, the steam pressure measured by the inlet side steam pressure gauge 19 is “entry side steam pressure P ₁ ”, the steam pressure measured by the outlet side steam pressure gauge 20 is “outside steam pressure P ₃ ”, and reduced pressure. All the vapor pressures measured by the valve inlet side pressure gauge 21 are sent to the drain controller 24 as “pressure reducing valve inlet side pressure P ₀ ”.

In the pressure reducing valve 8 described above, the pressure reducing valve inlet side pressure P ₀ measured by the pressure reducing valve inlet side pressure gauge 21 becomes a predetermined pressure (in the range of 0.000 to 0.169 MPaG) at which the steam binary power generation system operates normally. So that the pressure is adjusted.
The drain control unit 24 controls the operating state of the steam trap 9 and is composed of a personal computer and a sequencer. The drain control unit 24 operates the steam trap 9 when the outlet steam pressure P ₃ becomes larger than the inlet steam pressure P ₁ according to the program stored therein, and the outlet steam pressure P ₃ is changed to the inlet side. if it becomes less than the vapor pressure P _1, and has a configuration that stops the steam trap 9.

Next, signal processing performed in the drain control unit 24, in other words, an operation method of the binary power generator 1 of the present invention will be described.
First, the inlet steam pressure P ₁ is measured by the aforementioned inlet steam pressure gauge 19, and the outlet steam pressure P ₃ is measured by the outlet steam pressure gauge 20. The vapor pressure measured by each pressure gauge is sent to the drain control unit 24.

The drain controller 24 compares the inlet steam pressure P ₁ with the outlet steam pressure P _3, and if the result of the comparison is that the outlet steam pressure P ₃ is smaller than the inlet steam pressure P ₁ , the inside of the evaporator 2 Therefore, it is determined that no drain is generated, and the pump portion of the steam trap 9 is kept stopped. However, if the exit-side steam pressure P ₃ is greater than the inlet side steam pressure P ₁ is (evaporator 2 is closed by the drain) drain is generated in the evaporator 2 and the steam trap is determined The pump part 9 is operated and the drain is forcibly discharged. In this way, it becomes possible to quickly grasp the blockage of the steam pipe 7 by the drain and quickly eliminate the blockage, and stable power generation can be performed even when low-pressure steam that easily generates a drain is used as a heat source. It becomes possible.

If the drain is frequently discharged by using the above-described discharge mechanism, the amount of heat that moves from the vapor side to the working medium side in the evaporator 2 also changes frequently, and matches the change in the amount of heat that enters from the evaporator 2. Therefore, it is necessary to control the circulating amount of the working medium with good followability in order to continue stable power generation.
Therefore, in the binary power generation device 1 of the present invention, the following superheat degree control unit 25 is provided to control the circulation amount of the working medium to an appropriate one with good responsiveness.

  That is, in the binary power generation apparatus 1 described above, the outlet side medium pressure gauge 26 for measuring the pressure of the working medium and the outlet side medium thermometer for measuring the pressure of the working medium are provided in the circulation pipe 6 on the outlet side of the evaporator 2. 27 are provided. Then, in addition to the drain controller 24, the working medium on the outlet side of the evaporator 2 is based on the vapor pressure measured by the outlet medium pressure gauge 26 and the vapor temperature measured by the outlet medium thermometer 27. A superheat degree control unit 25 that calculates the superheat degree and controls the circulation amount and pressure of the working medium by the circulation pump 5 is provided so that the calculated superheat degree is included in a predetermined allowable range of the superheat degree. It has been.

That is, in the working medium circulation pipe 6, the outlet medium pressure gauge 26 for measuring the pressure of the working medium and the temperature of the working medium are measured between the evaporator 2 and the expander 3 (oil separator 15). And an exit side medium thermometer 27 is provided. Then, the superheat degree control unit 25 calculates the saturation temperature T _s when the steam pressure is P ₂ based on the steam pressure P ₂ measured by the outlet medium pressure gauge 26, and the calculated saturation temperature. The degree of superheating of the working medium is calculated based on T _s and the steam temperature T ₂ measured by the outlet medium thermometer 27. Further, the superheat degree control unit 25 sends a command to the circulation pump 5 via the inverter 23 so that the calculated superheat degree of the working medium falls within a preset superheat degree range.

For example, when the calculated superheat degree of the working medium becomes larger than a preset superheat degree, the rotational speed, voltage, or current of the circulation pump 5 is increased via the inverter 23 to thereby circulate the working medium. And increase the pressure. Further, when the calculated superheat degree of the working medium becomes smaller than a preset superheat degree, the rotational speed, voltage or current of the circulation pump 5 is reduced via the inverter 23, and the circulation amount of the working medium is reduced. And reduce the pressure. By using such a superheat degree control unit 25, it is possible to appropriately adjust the circulation amount and pressure of the working medium so that the superheat degree of the working medium on the outlet side of the evaporator 2 becomes a preset superheat degree. Thus, it is possible to make the power generation efficiency of the binary power generator 1 more efficient after the heat exchange in the evaporator 2 is stably performed.
[Second Embodiment]
Next, the binary power generator 1 of the second embodiment will be described.

As shown in FIG. 2, the binary power generator 1 of the second embodiment does not forcibly discharge the drain generated in the evaporator 2 by using a pump or the like, but depending on whether or not the drain is generated. The structure which switches suitably the path | route through which steam distribute | circulates is employ | adopted.
That is, the forced drain discharge means of the second embodiment includes a first drain pipe 28 having a large pressure loss during drain discharge and a second drain pipe 29 having a pressure loss during drain discharge smaller than that of the first drain pipe 28. Have. Then, the drain control unit 24 determines the second low pressure loss when the steam pressure P ₃ measured by the outlet steam pressure gauge 20 becomes larger than the steam pressure P ₁ measured by the inlet steam pressure gauge 19. when discharging the drain with a drain pipe 29, the steam pressure P ₃ measured by the exit-side steam pressure gauge 20, which is smaller than the vapor pressure P ₁ measured by the entry-side steam pressure gauge 19, pressure loss The first drain pipe 28 is used to discharge the drain.

Specifically, the following is applicable as the first drain pipe 28.
For example, when the heat source of the binary power generation apparatus 1 is steam that erupts from the underground or steam that originates from a hot water source that springs out, the recovered drain is returned to the underground hot water source again, or a remote location for secondary use. There are also cases where they are sent to a hot spring bath in the area. In such a case, a certain amount of pressure loss occurs because the drain is returned to the basement again or sent to a remote place by a pipe or the like. Therefore, a pipe for returning the drain to the underground again, a pipe for transferring the drain to a remote place, and the like correspond to the first drain pipe 28.

On the other hand, the second drain pipe 29 is a pipe having a smaller pressure loss when discharging the drain than the first drain pipe 28. As the second drain pipe 29, a drain that directly discharges the drain to the outside of the steam pipe 7, that is, a pipe that is open to the atmosphere can be used.
The first drain pipe and the second drain pipe 29 described above are formed by branching the steam pipe 7 downstream from the evaporator 2. That is, one of the branched steam pipes 7 is a first drain pipe 28, and the other branched steam pipe 7 is a second drain pipe 29, and the first drain pipe 28 and the second drain pipe 29 are connected to each other. A switching valve 30 capable of switching the delivery destination of steam and drain is provided at the branch location. This switching valve 30 can switch the delivery destination of steam and drain between the first drain pipe 28 and the second drain pipe 29 in accordance with the command from the drain control unit 24 described above.

In the drain controller 24 of the second embodiment described above, when the steam pressure P ₃ measured by the outlet steam pressure gauge 20 becomes smaller than the steam pressure P ₁ measured by the inlet steam pressure gauge 19. Then, it is determined that no drain is generated in the evaporator 2, and a command is sent to the switching valve 30, and the drain is discharged via the first drain pipe 28. However, if the steam pressure P ₃ is greater than the vapor pressure P ₁ switches the path by sending a command to the switching valve 30 determines that the drain is generated in the evaporator 2, first drain pipe The drain is discharged through the second drain pipe 29 having a pressure loss smaller than that of the second drain pipe 29. In this way, it is not necessary to employ a complicated mechanism such as a pump as a means for forcibly discharging the drain, and a simpler structure can be employed as the drain discharging mechanism.
[Third Embodiment]
Next, the binary power generator 1 of the third embodiment will be described.

As shown in FIG. 3, the binary power generator 1 according to the third embodiment uses a steam trap 9 that is driven using the pressure of steam flowing through the steam pipe 7.
Specifically, the steam trap 9 of the third embodiment flows through the steam pipe 7 to the steam pipe 7 on the inlet side of the evaporator 2, more precisely to the steam pipe 7 on the upstream side of the pressure reducing valve 8. A driving steam pipe 31 for drawing a part of the steam is provided. The other end of the driving steam pipe 31 is connected to a steam-driven pump (pump unit) that generates a suction force by the pressure of the steam. The driving steam pipe 31 is provided with a shutoff valve 32 that can shut off the flow of steam flowing through the pipe, and the shutoff valve 32 can be opened and closed by a command from the drain control unit 24 described above. .

Therefore, if a command is sent from the drain control unit 24 of the third embodiment and the shutoff valve 32 is closed, the steam of the driving source is not supplied and the steam trap 9 does not operate.
However, if a command is sent from the drain control unit 24 to open the shut-off valve 32, steam flows into the pump unit via the driving steam pipe 31, and suction force is generated in the pump unit of the steam trap 9 to forcibly drain the drain. Can be discharged.

Note that the configurations, operations, and effects of the third embodiment other than those described above are the same as those of the first embodiment. Therefore, detailed description is omitted.
“Fourth Embodiment”
Next, the binary power generator 1 of the fourth embodiment will be described.
As shown in FIG. 4, the binary power generator 1 of the fourth embodiment is different from the first to third embodiments in that the temperature of the drain that has passed through the evaporator 2 can be adjusted. . That is, in the binary power generation device 1 of the fourth embodiment, as in the first to third embodiments, the steam used for heat exchange with the working medium in the evaporator 2 passes through the steam pipe 7 and the forced drain discharge means ( In the example of FIGS. 1 to 3, the steam trap 9 is the forced discharge means, but in this embodiment, the member indicated by reference numeral 39 in FIG. 4 is the forced discharge means) The forced drain discharge means 39 forcibly discharges the outside.

However, when the temperature of the drain discharged by the forced drain discharging means 39 is very high, it may be difficult to reuse the drain after discharging, and therefore the temperature of the drain discharged outside is somewhat low. The temperature is preferably adjusted (cooled).
Therefore, in the binary power generator 1 of the fourth embodiment, the steam pipe 7 located on the outlet side of the evaporator 2 is branched into two, a drain branch pipe 35 and a drain mainstream pipe 36. A drain cooling / discharge switching valve 37 is provided at the position where the steam pipe 7 is branched to switch the drain outlet to the two steam pipes 35, 36. Of these two branched steam pipes, the drain branch pipe 35 which is one of the steam pipes is provided with drain cooling means 38 for cooling the drain flowing through the drain branch pipe 35. Further, the drain mainstream pipe 36 which is the other steam pipe is directly connected to a forced drain discharge means 39 which will be described later. Therefore, if the drain cooling / discharge switching valve 37 is switched to the drain branch pipe 35 side and the drain is guided to the drain cooling means 38 to cool the drain, the high-temperature drain is sent to the forced drain discharging means 39 as it is. Can be suppressed.

The drain thus cooled by the drain cooling means 38 is sent to the downstream side through the drain branch pipe 35. Then, on the downstream side of the drain cooling means 38, the branched drain branch pipe 35 and the drain mainstream pipe 36 are joined again to form one steam pipe 7 (hereinafter referred to as a drain junction pipe 47).
The drain junction pipe 47 is connected to a forced drain discharge means 39 for forcibly discharging the drain. The drain junction pipe 47 is provided with drain temperature measuring means 40 for measuring the temperature of the drain flowing through the drain junction pipe 47. The drain temperature measured by the drain temperature measuring means 40 is sent to a drain temperature control controller 43 (corresponding to the drain control unit 24 of the first to third embodiments) described later.

  On the other hand, in the binary power generation device 1 of the fourth embodiment, similarly to the first to third embodiments, the cooling water used for condensing the working medium in the condenser 4, that is, one of the condensers 4 constituting the heat exchanger. The cooling water supplied to the next side is sent to the cooling tower 10 (chiller) through the cooling water pipe 11 by the action of the cooling water pump 12. The difference between the binary power generation apparatus 1 of the fourth embodiment and the first to third embodiments is that the cooling water pipe 11 directed to the cooling tower 10 (chiller) is branched into two, and the branched drain A part of the cooling water flowing through the cooling water pipe 11 through the cooling water pipe 41 is introduced into the drain cooling means 38.

Specifically, the drain cooling water pipe 41 branches from the middle side of the cooling water pipe 11 from the condenser 4 to the cooling tower 10, and a part of the cooling water flowing through the cooling water pipe 11 is supplied to the drain cooling means 38. It has been introduced. The cooling water introduced into the drain cooling means 38 in this way is sent to the cooling tower 10 and is cooled again in this cooling tower 10.
The drain cooling water pipe 41 has a drain cooling water flow rate adjustment valve 42 for adjusting the flow rate of the cooling water flowing through the drain cooling water pipe 41 and the temperature of the cooling water flowing through the drain cooling water pipe 41. And a drain cooling water thermometer 46 is provided. The drain cooling water flow rate adjusting valve 42 is provided in the drain cooling water pipe 41 between the branch source cooling water pipe 11 and the drain cooling means 38, and the valve opening degree is a command of the drain temperature control controller 43. And a flow rate of cooling water introduced into the drain cooling means 38 can be adjusted. Further, the temperature of the cooling water measured by the drain cooling water thermometer 46 is sent to the drain temperature control controller 43 described later.

  In the binary power generator 1 of the fourth embodiment, an inlet-side evaporation thermometer 44 for measuring the temperature of steam flowing through the inlet-side steam pipe 7 is connected to the steam pipe 7 positioned on the inlet side of the evaporator 2; An inlet-side evaporation pressure gauge 19 that measures the pressure of the inlet-side steam is provided. The steam pipe 7 positioned on the outlet side of the evaporator 2 includes an outlet-side evaporation thermometer 45 that measures the temperature of the steam flowing through the outlet-side steam pipe 7, and an outlet that measures the pressure of the outlet-side steam. A side evaporation pressure gauge 20 is provided. The temperature and pressure measured by these thermometers and pressure gauges are sent to a steam binary main body controller 25 (corresponding to the superheat degree control unit of the first to third embodiments) that controls the superheat degree of the evaporator 2. The vapor binary main body controller 25 sends a drain temperature control controller 43 (corresponding to the drain control unit 24 of the first to third embodiments) that controls the drain temperature.

  The drain temperature control controller 43 described above adjusts the opening degree of the drain cooling water flow rate adjustment valve 42 described above based on the drain temperature measured by the drain temperature measuring means 40, and The flow rate of circulating cooling water can be adjusted. For the drain temperature control controller 43, for example, a personal computer or a process computer attached to the equipment is used.

Next, signal processing performed inside the drain temperature control controller 43, in other words, an operation method of the binary power generation device of the fourth embodiment will be described.
As shown in FIG. 6, in the binary power generation device of the fourth embodiment, first, an inlet-side steam pressure gauge 19 provided in the inlet-side steam pipe 7 of the evaporator 2 uses a drain pressure PS1 on the inlet side of the evaporator 2. Is measured. In addition, a drain pressure PS3 on the outlet side of the evaporator 2 is measured by an outlet side steam pressure gauge 20 provided in the steam pipe 7 on the outlet side of the evaporator 2. The drain pressure PS1 on the inlet side of the evaporator 2 and the drain pressure PS3 on the outlet side of the evaporator 2 thus measured are sent to the superheat degree control unit 25.

  The superheat degree control unit 25 compares the pressure PS1 of the drain on the inlet side of the evaporator 2 with the pressure PS3 of the drain on the outlet side of the evaporator 2 (S001), and if the pressure PS3 is larger than the pressure PS1, the evaporator 2, the drain is forcibly discharged by operating the forced drain discharge means 39 (S002). This forced draining of the drain stops when the pressure PS3 becomes smaller than the pressure PS1 (S003). Further, the signal for forcibly discharging the drain is also sent to the controller 43 for controlling the drain temperature.

When the drain is forcibly discharged in this way, the drain temperature control controller 43 first determines whether or not the pressure of the vapor supplied to the evaporator 2 has dropped (S004).
In other words, the steam supplied to the evaporator 2 may temporarily drop depending on the state of the steam supply source, etc., and the drain is blocked in the evaporator 2 even when the pressure of the steam is reduced, and heat exchange is performed. May cause problems such as being unable to fully perform. Therefore, in the binary power generation device 1 of the present embodiment, it is determined whether or not the pressure of the steam is reduced based on whether or not the pressure PS1 measured by the inlet-side steam pressure gauge 19 is smaller than a predetermined minimum pressure value PS1min.

  Specifically, when the pressure PS1 of the inlet-side steam pressure gauge 19 is equal to or less than a predetermined minimum value PS1min, it is determined that the pressure of the steam supplied to the evaporator 2 has decreased, and drain cooling Switch the discharge switching valve 37 to the “ON state” (S005). When the pressure PS1 is larger than the minimum pressure value PS1min, it is determined that the pressure of the steam supplied to the evaporator 2 is sufficiently high, in other words, sufficient heat exchange is performed in the evaporator 2, and the drain The cooling / discharge switching valve 37 is switched to the “OFF state” (S006).

  In the drain cooling / discharge switching valve 37 described above, as shown in FIG. 5, when the drain cooling / discharge switching valve 37 is in the “ON state”, the drain branch pipe 35 is closed and the drain main flow pipe 36 is opened. The Therefore, the drain of the steam pipe 7 is not cooled by the drain cooling means 38 of the drain branch pipe 35, and the drain is sent to the forced drain discharge means 39. On the other hand, when the drain cooling / discharge switching valve 37 is in the “OFF state”, the drain branch pipe 35 is opened and the drain mainstream pipe 36 is closed. Therefore, the drain of the steam pipe 7 is cooled by the drain cooling means 38 of the drain branch pipe 35, and the temperature of the drain is adjusted, that is, the drain is cooled.

  Next, the drain temperature TS2 in the steam pipe 7 on the outlet side of the evaporator 2 is measured by the outlet steam thermometer 45, and the drain temperature TS2 measured by the outlet steam thermometer 45 is equal to or higher than a predetermined TDmax. If so, the drain cooling water flow rate adjustment valve 42 of the drain cooling water pipe 41 is opened (S007). Then, the cooling water flows through the drain cooling water pipe 41, and the drain is cooled by the drain cooling means 38 of the drain branch pipe 35. As a result, the drain cooling means 38 cools the drain, and the temperature of the drain sent to the forced drain discharging means 39 can be lowered.

  If the drain temperature TS2 measured by the outlet steam thermometer 45 is smaller than the predetermined TDmax, the drain cooling water flow rate adjustment valve 42 of the drain cooling water pipe 41 is closed (S008). If it does so, the flow volume of the cooling water which distribute | circulates the drain cooling water piping 41 will decrease, and a drain will not be cooled by the drain cooling means 38. FIG. In the flowchart of FIG. 6, the flow rate of the cooling water flowing through the drain cooling water pipe 41 is decreased, and then the process returns to the beginning.

The drain temperature TS2 measured by the outlet side steam thermometer 45 is a predetermined TDma.
If it is determined that the temperature is equal to or greater than x, the drain temperature TD1 is measured by the drain temperature measuring means 40 provided in the steam pipe 7 after joining. Then, it is determined whether the drain temperature TD1 measured by the drain temperature measuring means 40 is higher or lower than a predetermined TDmax ± α (S009).

  That is, when the drain temperature TD1 is equal to or higher than a predetermined TDmax + α, the opening degree of the drain cooling water flow rate adjustment valve 42 of the drain cooling water pipe 41 is increased (S010), and the drain cooling means 38 further cools the drain. Like that. In this way, the temperature of the drain flowing through the drain junction pipe 47 is lowered, and the temperature of the drain sent to the forced drain discharge means 39 can be kept low.

  On the other hand, when the drain temperature TD1 is equal to or lower than a predetermined TDmax−α, the opening degree of the drain cooling water flow rate adjustment valve 42 of the drain cooling water pipe 41 is lowered (S011), and the drain cooling means 38 Try to suppress cooling. By doing so, the temperature of the drain flowing through the drain junction pipe 47 becomes high, and the temperature of the drain sent to the forced drain discharge means 39 can be increased.

  If a value such as TDmax ± α described above is used as the drain temperature TD1, the drain temperature can be controlled in the range of (TDmax−α) to (TDmax + α). On the other hand, finer temperature control can be performed. In addition, when the pressure of the steam supplied to the evaporator 2 is reduced, it is possible to suppress the drain from being blocked inside the evaporator 2.

In the above-described embodiment, the configuration in which a part of the cooling water directed to the cooling tower 10 (chiller) is introduced into the drain cooling means 38 is described. However, the drain cooling water pipe 41 is connected to another water source such as factory water. In addition, a configuration in which the cooling water of the water source is introduced into the drain cooling means 38 can be adopted.
The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. In particular, in the embodiment disclosed this time, matters that are not explicitly disclosed, for example, operating conditions and operating conditions, various parameters, dimensions, weights, volumes, and the like of a component deviate from a range that a person skilled in the art normally performs. Instead, values that can be easily assumed by those skilled in the art are employed.

DESCRIPTION OF SYMBOLS 1 Binary power generation device 2 Evaporator 3 Expander 4 Condenser 5 Circulation pump 6 Circulation piping 7 Steam piping 8 Pressure reducing valve 9 Steam trap 10 Cooling tower 11 Cooling water piping 12 Cooling water pump 13 Generator 14 Lubrication means 15 Oil separator 16 Lubricating oil supply pipe 17 Preheater 18 Drive shaft 19 Inlet side steam pressure gauge 20 Outlet side medium pressure gauge 21 Pressure reducing valve inlet side pressure gauge 23 Inverter 24 Drain control part 25 Superheat degree control part 26 Outlet side medium pressure gauge 27 Outlet side medium Thermometer 28 First drain pipe 29 Second drain pipe 30 Switching valve 31 Drive steam pipe 32 Shutoff valve 35 Drain branch pipe 36 Drain mainstream pipe 37 Drain cooling / discharge switching valve 38 Drain cooling means 39 Forced drain discharge means 40 Drain temperature Measuring means 41 Drain cooling water piping 42 Drain cooling water The amount adjustment valve 43 drains the temperature control controller 44 entry side evaporation temperature gauge 45 exit side evaporating thermometer 46 drain the coolant temperature gauge 47 drain collecting pipe

Claims (7)

An evaporator that evaporates the working medium using steam having a pressure of 0.2 MPaG or less as a heat source, an expander that generates a rotational driving force by expanding the gaseous working medium evaporated by the evaporator, and the expander that is expanded. A method for operating a binary power generator comprising a condenser for condensing a gaseous working medium into a liquid and a circulation pump for circulating the working medium from the condenser toward an evaporator,
An inlet-side steam pressure gauge for measuring the inlet-side steam pressure of the evaporator, an outlet-side steam pressure gauge for measuring the outlet-side steam pressure of the evaporator, and a drain accumulated in the evaporator outside the steam pipe And a forced drain discharge means for forcibly discharging,
Binary wherein the exit-side steam pressure P ₃ measured by the steam pressure gauge, if it becomes larger than the vapor pressure P ₁ measured by the entry-side steam pressure gauge, and wherein the actuating said forced drain discharge means How to operate the power generator. Claims wherein the exit side steam pressure P ₃ measured by the steam pressure gauge, if it becomes less than the vapor pressure P ₁ measured by the entry-side steam pressure gauge, characterized in that stopping the forced drain discharge means Item 2. A method for operating the binary power generator according to Item 1.   3. The binary according to claim 1, wherein the forced drain discharge means forcibly discharges the vapor drain to the outside of the evaporator by using the vapor pressure on the inlet side of the evaporator as a driving force. 4. How to operate the power generator. The forced drain discharge means includes a first drain pipe having a large pressure loss during drain discharge and a second drain pipe having a pressure loss during drain discharge smaller than that of the first drain pipe.
Wherein the exit-side steam pressure P ₃ measured by the steam pressure gauge, if it becomes larger than the vapor pressure P ₁ measured by the entry-side steam pressure gauge, with the second drain pipe, to discharge the drain,
Said the exit side steam pressure P ₃ measured by the steam pressure gauge, if it becomes less than the vapor pressure P ₁ measured by the entry-side steam pressure gauge, with the first drain pipe, to discharge the drain The operation method of the binary power generator according to any one of claims 1 to 3. On the outlet side of the evaporator, an outlet medium pressure gauge that measures the pressure of the working medium and an outlet medium thermometer that measures the temperature of the working medium are provided,
Based on the steam pressure measured by the outlet medium pressure gauge and the steam temperature measured by the outlet medium thermometer, the degree of superheat of the working medium on the outlet side of the evaporator is calculated, and the calculated degree of superheat The binary power generation according to any one of claims 1 to 4, wherein the circulation amount and the pressure of the working medium by the circulation pump are controlled so as to be included in a predetermined allowable range of superheat. How to operate the device. Drain cooling that branches the steam pipe located on the outlet side of the evaporator into a drain mainstream pipe and a drain branch pipe and switches the drain outlet to the drain mainstream pipe and the drain branch pipe at the branch position.・ Establish discharge switching valve
The drain branch pipe is provided with a drain cooling means for cooling the circulating drain,
On the downstream side of the drain cooling means, the drain branch pipe and the drain mainstream pipe are joined to form a drain junction pipe,
Connecting the drain confluence pipe to the forced drain discharge means;
Furthermore, the drain junction pipe is provided with a drain temperature measuring means for measuring the temperature of the drain,
A drain cooling water flow rate adjustment valve capable of adjusting the flow rate of cooling water introduced into the drain cooling means is provided,
The binary power generator according to any one of claims 1 to 5, wherein a valve opening degree of the drain cooling water flow rate adjustment valve is adjusted based on a temperature of the drain measured by the drain temperature measuring means. Driving method.   The operation method of the binary power generator according to claim 6, wherein a part of cooling water used for condensing the working medium in the condenser is introduced into the drain cooling means.

Images