JP6223886B2 - Power generator - Google Patents

Description

  The present invention relates to a power generator.

  Conventionally, as disclosed in Patent Document 1 below, a binary power generation apparatus is known in which a generator is driven by an expander provided in a circulation pipe through which a working medium circulates. As shown in FIG. 7, in the binary power generation device disclosed in Patent Document 1, an evaporator 71, an expander 72, a condenser 73, and a circulation pump 74 are connected to a circulation pipe 75 in this order. The evaporator 71 evaporates the working medium using waste water discharged from the factory or hot water from the hot spring as a heat source. Temperature measuring means 76 is provided on the outlet side of the evaporator 71 in the flow path through which the heat source flows. Based on this measured value, the rotational speed of the circulation pump 74 is adjusted. That is, when the temperature of the hot water on the outlet side of the evaporator 71 becomes higher than the target value, the hot water temperature on the outlet side is lowered by increasing the number of revolutions of the circulation pump 74.

JP 2013-181398 A

  In the binary power generator disclosed in Patent Document 1, when the temperature of hot water as a heat source rises, the temperature of hot water flowing out from the evaporator 71 is lowered by increasing the number of revolutions of the circulation pump 74. Thereby, the temperature of the hot water flowing out from the evaporator 71 can be kept within a predetermined range. However, this binary power generation apparatus still has a problem that it cannot cope with the case where the temperature of hot water (heat source) rises rapidly. That is, when the temperature of the hot water on the outlet side of the evaporator 71 rises, adjustment is made to increase the number of revolutions of the circulation pump 74. The superheat degree at the outlet of the evaporator temporarily increases. For this reason, there exists a problem that the packing of the flange which exists in the path | route from the evaporator 71 to the expander 72 must be comprised with a heat resistant material.

  Therefore, the present invention has been made in view of the above-described prior art, and an object of the present invention is to make it possible to suppress an increase in the temperature of the working medium on the outlet side of the evaporator in the power generation device.

  To achieve the above object, the present invention provides an expander that expands a gaseous working medium, a condenser that condenses the working medium expanded by the expander, and pressurizes the working medium condensed by the condenser. A pump, a heater that evaporates at least a part of the working medium pressurized by the pump with heat of a heat source medium, and a working medium that is in a superheated state and is at a predetermined temperature or higher downstream of the heater And a cooling means for cooling the generator.

  In the present invention, the cooling means cools the working medium in a superheated state in which the temperature on the downstream side of the heater is equal to or higher than a predetermined value. For this reason, the temperature of the working medium flowing out of the heater and flowing into the expander can be suppressed. Therefore, even when the temperature of the heat source medium suddenly rises, the temperature rise of the working medium can be effectively suppressed. Therefore, the flange packing existing in the path from the heater to the expander can be removed. It is no longer necessary to use heat-resistant materials, and measures such as raising the class of insulating materials used in generators are not necessary.

  The cooling means may be configured to cool the overheated working medium by a working medium that is diverted downstream from the pump and upstream from the heater. In this aspect, since the overheated working medium is cooled by the working medium discharged from the pump, it is possible to suppress complication of the configuration as the power generation device.

  The cooling means may be configured to cool the overheated working medium by joining the working medium branched from the downstream side of the pump to the working medium downstream of the heater. In this aspect, the working medium branched from the downstream side of the pump joins the working medium in an overheated state, thereby cooling the working medium. Therefore, the working medium can be cooled more effectively.

  The cooling means may perform cooling in a range in which the working medium on the downstream side of the heater is maintained at a saturation temperature or higher. In this aspect, the liquid working medium can be prevented from being introduced into the expander. Therefore, it is possible to prevent the power generation efficiency from being lowered.

  The cooling means may cool the overheated working medium using heat of vaporization. In this aspect, since the superheated working medium is cooled using the heat of vaporization, the working medium can be cooled more effectively. That is, the superheated working medium can be cooled with a small amount of the cooling medium. In particular, when the working medium that is diverted from the downstream side of the pump is used as the cooling medium, the amount of the working medium that is sent from the pump to the evaporator is only slightly reduced. For this reason, even if it is made to divert from the working medium discharged from the pump, there is almost no influence.

  The cooling means includes a working medium flow path and a cooling flow path, and includes a heat exchanger disposed on the downstream side of the heater, and a decompression means provided in a heat medium circuit connected to the cooling flow path. You may have. The decompression means may decompress the heat medium so that the working medium is cooled in the heat exchanger when the working medium is in an overheated state and is equal to or higher than a predetermined temperature.

  In this aspect, when the working medium is in an overheated state and is equal to or higher than a predetermined temperature, the working medium flowing through the working medium flow path is decompressed by the pressure reducing means of the heat medium circuit in the heat exchanger, and the cooling flow path It is cooled by the heat medium flowing through. On the other hand, when the working medium is not sufficiently heated in the heater, the working medium is heated by the heat medium in the heat exchanger. Therefore, the heat exchanger can cool the working medium when the working medium is heated excessively, while it can supplementarily heat the working medium when the working medium is not sufficiently heated. .

  As described above, according to the present invention, the temperature increase of the working medium on the outlet side of the evaporator can be suppressed in the power generation device.

It is a figure showing roughly the composition of the power generator concerning a 1st embodiment of the present invention. It is a figure for demonstrating the control action in the electric power generating apparatus which concerns on 1st Embodiment. It is a figure which shows schematically the structure of the electric power generating apparatus which concerns on 2nd Embodiment of this invention. It is a figure for demonstrating the control action in the electric power generating apparatus which concerns on 2nd Embodiment. It is a figure which shows roughly the structure of the electric power generating apparatus which concerns on other embodiment of this invention. It is a figure which shows roughly the structure of the electric power generating apparatus which concerns on other embodiment of this invention. It is a figure which shows schematically the structure of the conventional binary electric power generating apparatus.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.

  The power generation apparatus 1 according to the first embodiment is a power generation system using a Rankine cycle, and includes a condenser 6, a circulation pump 8, an evaporator 10, and an expander 14, as shown in FIG. . The condenser 6, the circulation pump 8, the heater 10, and the expander 14 are provided in the circulation flow path 4 in this order. In the power generation device 1 according to the present embodiment, a circulation circuit is configured in which the working medium flows in order through the heater 10, the expander 14, the condenser 6, and the circulation pump 8 through the circulation flow path 4. As the working medium, a refrigerant having a boiling point lower than that of water is used.

  A generator 16 is connected to the expander 14. By expanding the gaseous working medium in the expander 14, the force for driving the generator 16 can be taken out.

  The condenser 6 condenses the gaseous working medium discharged from the expander 14 to form a liquid working medium. The condenser 6 has a working medium flow path 6a through which a gaseous working medium flows and a cooling medium flow path 6b through which a cooling medium such as cooling water flows. The cooling medium flow path 6b is connected to a cooling circuit 61, and a cooling medium such as cooling water supplied from the cooling circuit 61 flows therethrough. The working medium flowing through the working medium flow path 6a is condensed by exchanging heat with the cooling medium flowing through the cooling medium flow path 6b.

  The circulation pump 8 is provided on the downstream side of the condenser 6 in the circulation channel 4 (between the heater 10 and the condenser 6) and circulates the working medium in the circulation channel 4. . The circulation pump 8 pressurizes the liquid working medium condensed by the condenser 6 to a predetermined pressure and sends it to the heater 10. As the circulation pump 8, a centrifugal pump having an impeller as a rotor, a gear pump having a rotor composed of a pair of gears, or the like is used.

  The heater 10 is provided on the downstream side of the circulation pump 8 in the circulation channel 4 (between the circulation pump 8 and the expander 14). The heater 10 has a working medium flow path 10a through which the working medium flows and a heat source medium flow path 10b through which the heat source medium flows. The heat source medium flow path 10b is connected to the heat source medium circuit 62, and a heat source medium supplied from an external heat source flows through the heat source medium flow path 10b. The working medium flowing through the working medium flow path 10a evaporates by exchanging heat with the heat source medium flowing through the heat source medium flow path 10b. Examples of the heat source medium include warm water and water vapor.

  In the circulation channel 4, a shut-off valve (open / close valve) 21 is provided between the heater 10 and the expander 14. The shut-off valve 21 is normally opened, but is closed when the expander 14 is stopped, such as when the expander 14 is abnormal.

  The circulation channel 4 is provided with a bypass unit 23 and a cooling unit 25. The bypass means 23 includes a bypass path 23a that bypasses the expander 14, and an on-off valve 23b provided in the bypass path 23a. The on-off valve 23b is normally closed, but is opened when the expander 14 is stopped, such as when the expander 14 rotates abnormally. By opening the on-off valve 23b, the working medium flowing out of the heater 10 is introduced into the condenser 6 without being introduced into the expander 14.

  The cooling means 25 is for cooling the gaseous working medium evaporated by the heater 10 (that is, taking away sensible heat), and includes a cooling passage 25a and a cooling valve provided in the cooling passage 25a ( On-off valve) 25b. One end of the cooling passage 25 a is connected to a portion of the circulation channel 4 between the circulation pump 8 and the heater 10. Accordingly, the liquid working medium flows into the cooling passage 25a. The other end of the cooling passage 25 a is connected to a portion of the circulation channel 4 between the heater 10 and the expander 14. For this reason, the liquid working medium that has flowed through the cooling passage 25 a merges with the gaseous working medium that has flowed out of the evaporator 10.

  The cooling passage 25 a is constituted by a pipe having a smaller diameter than the pipe constituting the circulation flow path 4. Therefore, a working medium having a flow rate sufficiently smaller than the working medium flowing through the circulation flow path 4 flows through the cooling passage 25a. Alternatively, the cooling passage 25a may be provided with a throttle or a capillary tube (not shown).

  The cooling valve 25b is normally closed, and is opened when a command from the controller 30 described later is received.

  In the circulation channel 4, a temperature sensor 32 and a pressure sensor 34 are provided between a portion where the downstream end of the cooling passage 25 a is connected and the expander 14. The temperature sensor 32 detects the temperature of the working medium that flows out of the heater 10 and is introduced into the shut-off valve 21 and the expander 14. The pressure sensor 34 detects the pressure of the working medium that flows out of the evaporator 10 and is introduced into the shut-off valve 21 and the expander 14.

  The power generation apparatus 1 is provided with a controller 30 that performs drive control of the circulation pump 8 and open / close control of the open / close valves 21, 23b, and 25b. The functions of the controller 30 include a pump control unit 30a and a cooling control unit 30b.

  The pump control means 30a is a means for controlling the rotational speed of the circulation pump 8, and circulates so that the degree of superheating of the working medium derived from the detection values of the temperature sensor 32 and the pressure sensor 34 falls within a preset range. Drive control of the pump 8 is performed.

  The cooling control means 30b is means for controlling the opening and closing of the cooling valve 25b, and executes the opening and closing control of the cooling valve 25b based on the temperature of the working medium that has flowed out of the heater 10. That is, the cooling control means 30b determines the detection value of the temperature sensor 32 in advance when it is determined from the detection values of the temperature sensor 32 and the pressure sensor 34 that the working medium downstream of the heater 10 is in an overheated state. When it is determined that the temperature is equal to or higher than the specified temperature (reference temperature), a command for opening the cooling valve 25b is output. As this reference temperature, a temperature is set so as not to damage the unillustrated packing or the like provided at the connection portion of the shut-off valve 21. That is, even when the packing is not composed of a heat-resistant material, the temperature of the working medium at the outlet of the heater 10 is controlled so as not to be damaged by the heat received from the working medium.

  Moreover, the cooling control means 30b performs closing control of the cooling valve 25b so as to perform cooling in a range in which the working medium on the downstream side of the heater 10 is maintained at the saturation temperature or higher. That is, the cooling control means 30b outputs a command to close the cooling valve 25b when a predetermined closing condition is satisfied so that the working medium introduced into the expander 14 is maintained at a saturation temperature or higher. As this closing condition, for example, the degree of superheat of the working medium obtained from the detection values of the temperature sensor 32 and the pressure sensor 34 is equal to or higher than a predetermined temperature. Note that the temperature of the working medium at this time is lower than the reference temperature.

  Here, the operation of the power generation system according to the first embodiment will be described. During normal operation, the shut-off valve 21 is open, while the on-off valve 23b and the cooling valve 25b of the bypass path 23a are closed.

  When the circulation pump 8 is driven, the liquid working medium delivered from the circulation pump 8 flows into the working medium flow path 10 a of the heater 10. The working medium is heated and evaporated by the heat source medium flowing through the heat source medium flow path 10b. The working medium evaporated by the heater 10 is introduced into the expander 14. When the working medium is introduced into the expander 14, the expander 14 is rotationally driven, and thereby the generator 16 is driven to generate power. The working medium expanded in the expander 14 is discharged to the circulation channel 4. The gaseous working medium discharged from the expander 14 is introduced into the working medium flow path 6 a of the condenser 6. In the condenser 6, the working medium is cooled and condensed by the cooling medium flowing through the cooling medium flow path 6b. This liquid working medium flows through the circulation flow path 4 and is sucked into the circulation pump 8. In the circulation channel 4, such circulation is repeated and power generation is performed in the generator 16.

  During operation of the power generation device 1, the rotational speed of the circulation pump 8 is controlled so that the degree of superheating of the working medium on the downstream side of the heater 10 is within a predetermined range. That is, as shown in FIG. 2, the detected values P1, T1 of the pressure sensor 34 and the temperature sensor 32 are input to the controller 30 (step ST1), and the pump control means 30a operates based on the detected values P1, T1. The circulation pump 8 is controlled so that the degree of superheat of the medium falls within a preset range (step ST2).

  The cooling control means 30b confirms whether or not the working medium is in an overheated state based on the detection values P1 and T1 of the pressure sensor 34 and the temperature sensor 32, and then sets the detection value T1 of the temperature sensor 32 in advance. It is determined whether or not it is equal to or lower than the reference temperature (upper limit value) Tr (steps ST3 and ST4). When it is determined that the detected value T1 of the temperature sensor 32 exceeds the reference temperature Tr when the working medium is in an overheated state, the cooling valve 25b is opened (step ST5). Such a situation occurs, for example, when the temperature of the heat source medium introduced into the heater 10 has suddenly increased, and cannot be dealt with by increasing the rotational speed of the circulation pump 8.

  When the cooling valve 25b is opened, a part of the liquid working medium discharged from the circulation pump 8 is diverted to the cooling passage 25a. Then, the liquid working medium that has flowed through the cooling passage 25 a joins the working medium in the overheated state in the circulation flow path 4. Therefore, the gaseous working medium that flows out of the heater 10 and flows through the circulation passage 4 toward the shut-off valve 21 and the expander 14 is cooled by vaporizing the combined liquid working medium. The liquid working medium introduced from the cooling passage 25a into the circulation flow path 4 downstream of the heater 10 lowers the temperature of the gaseous working medium in the circulation flow path 4 flowing out from the heater 10, that is, Because it only needs to take away sensible heat, it does not require a large amount of heat compared to taking away latent heat. For this reason, a small amount of the liquid working medium is sufficient.

  In addition, since the cooling passage 25a is configured by a pipe having a diameter smaller than that of the circulation passage 4, a large amount of working medium is prevented from flowing through the cooling passage 25a. For this reason, the amount of the working medium flowing into the heater 10 through the circulation flow path 4 does not decrease to the extent that the amount of the working medium accumulated in the heater 10 is affected, and the degree of superheat hardly increases further. .

  In a state where the cooling valve 25b is opened, it is determined whether or not the superheat degree SH calculated from the detection values T1 and P1 of the temperature sensor 32 and the pressure sensor 34 is equal to or higher than the reference superheat degree (lower limit value) SHr. (Step ST6). When the superheat degree SH becomes lower than the reference superheat degree SHr, the cooling valve 25b is closed (step ST7). As a result, the operation medium discharged from the circulation pump 8 returns to the normal operation introduced into the heater 10 without being divided into the cooling passage 25a.

  As described above, in the first embodiment, the cooling unit 25 cools the working medium in a superheated state in which the temperature on the downstream side of the heater 10 is equal to or higher than a predetermined value. For this reason, the temperature of the working medium flowing out of the heater 10 and flowing into the expander 14 can be suppressed. Therefore, even when the temperature of the heat source medium suddenly rises, the temperature rise of the working medium can be effectively suppressed. Therefore, the flange packing existing in the path from the heater 10 to the expander 14 can be suppressed. Etc. need not be made of heat resistant materials, and measures such as raising the class of insulating materials used in the generator 16 are not necessary.

  In the first embodiment, the cooling means 25 is configured to cool the working medium by joining the working medium divided from the downstream side of the pump and the upstream side of the heater 10 to the circulation flow path 4. Therefore, it is possible to suppress the complication of the configuration, and it is possible to cool the working medium more effectively.

  In the first embodiment, since the working medium on the downstream side of the heater 10 is maintained at the saturation temperature or higher, the liquid working medium can be prevented from being introduced into the expander 14. Therefore, it is possible to prevent the power generation efficiency from being lowered.

  Moreover, since 1st Embodiment cools the working medium in an overheated state using the vaporization heat of a working medium, it can cool a working medium more effectively. That is, the superheated working medium can be cooled with a small amount of the cooling medium. In particular, since the working medium branched from the downstream side of the circulation pump 8 is used as the cooling medium, the amount of the working medium sent from the circulation pump 8 to the heater 10 is slightly reduced. For this reason, even if the working medium discharged from the circulation pump 8 is diverted, there is almost no influence.

  FIG. 3 shows a power generator 1 according to the second embodiment. In the power generator 1 according to the second embodiment, the cooling unit 25 includes a heat exchanger 25f that cools the overheated working medium with a heat medium such as steam, high-temperature air, or hot water introduced from the outside. Also good. For example, the heat exchanger 25f is applied when the heat source medium circuit 62 connected to the heater 10 is configured by a flow path through which supercharged air to the engine (not shown) flows. The heat exchanger 24 f is provided on the downstream side of the heater 10 in the circulation circuit 4. Surplus steam may be introduced into the cooling flow path 25e of the heat exchanger 25f from a steam facility (not shown) provided in a ship on which the engine is mounted. When the engine is operating at a high load, for example, supercharged air of about 150 ° C. or higher is introduced into the heater 10. For this reason, the working medium flowing through the working medium flow path 10a of the heater 10 is heated to a temperature of about 150 ° C. In this case, the heat medium is depressurized by reducing the opening degree of the cooling valve (decompression means) 25b provided in the cooling passage 25a of the cooling means 25, thereby lowering the temperature of the heat medium. Thus, the overheated working medium flowing through the working medium flow path 25d of the heat exchanger 25f can be cooled. Note that when the engine is operated at a low load, the working medium may not be sufficiently heated in the heater 10, and at this time, the heat exchanger 25f is a superheater that heats the working medium to an overheated state. Can also work.

  As shown in FIG. 4, in the power generation system according to this embodiment, whether or not the working medium is in an overheated state is confirmed based on the detection values P1 and T1 of the pressure sensor 34 and the temperature sensor 32 (step ST3). When it is determined that the detected value T1 of the temperature sensor 32 exceeds the reference temperature Tr when the working medium is in an overheated state (step ST4), the cooling control unit 30b sets the cooling valve 25b. Control to narrow down is performed (step ST11). Thereby, the heat medium is depressurized, and the working medium is cooled in the heat exchanger 25f (sensible heat of the working medium is taken).

  The present invention is not limited to the first embodiment and the second embodiment, and various changes and improvements can be made without departing from the spirit of the present invention. For example, in the first embodiment, the working medium branched from the circulation flow path 4 is joined again to the working medium in the circulation flow path 4 on the downstream side of the heater 10 and directly exchanges heat. Alternatively, as shown in FIG. 5, the working medium branched into the cooling passage 25 a and the working medium in the circulation flow path 4 may indirectly exchange heat.

  Specifically, the cooling means 25 has a cooling heat exchanger 25 c disposed on the downstream side of the heater 10 in the circulation flow path 4. The cooling heat exchanger 25c is provided with a working medium channel 25d connected to the circulation channel 4 and a cooling channel 25e connected to the cooling channel 25a.

  One end (upstream end) of the cooling passage 25 a is connected to a portion of the circulation flow path 4 between the circulation pump 8 and the heater 10. The other end (downstream end) of the cooling passage 25 a is connected to a portion between the expander 14 and the condenser 6 in the circulation flow path 4. Since the downstream end portion of the cooling passage 25a is located on the suction side of the circulation pump 8 in the circulation passage 4, the working medium divided into the cooling passage 25a can easily flow.

  The liquid working medium branched from the circulation passage 4 to the cooling passage 25a is vaporized while cooling the working medium passage 25d in the overheated state in the cooling heat exchanger 25c. The vaporized working medium is returned to the upstream side of the condenser 6 in the circulation channel 4 from the cooling passage 25a.

  In the first embodiment, the overheated working medium is cooled by the liquid working medium. Alternatively, as shown in FIG. 6, the overheated working medium may be cooled by the cooling medium (cooling water) of the cooling circuit 61 that has passed through the condenser 6. Specifically, one end portion (upstream end portion) of the cooling passage 25 a is connected to a downstream portion of the condenser 6 in the cooling circuit 61. The cooling medium that has flowed through the cooling passage 25 a is returned to the cooling circuit 61. In this configuration, in the cooling heat exchanger 25c, the cooling medium in the cooling flow path 25e cools the working medium in the working medium flow path 25d in an overheated state.

  In each of the above-described embodiments, a jacket that covers a part of the piping portion between the heater 10 and the expander 14 in the circulation channel 4 is provided, and the working medium and the cooling fluid are caused to flow from the heater 10 in the jacket. The working medium that has flowed out may be cooled indirectly.

  The cooling valve 25a may be a valve whose opening degree can be adjusted.

DESCRIPTION OF SYMBOLS 1 Power generator 4 Circulation flow path 6 Condenser 8 Circulation pump 10 Heater 14 Expander 16 Generator 21 Shut-off valve 25 Cooling means 25a Cooling passage 25b Cooling valve 25c Cooling heat exchanger 25f Heat exchanger 30 Controller 30a Pump Control means 30b Cooling control means 32 Temperature sensor 34 Pressure sensor

Claims (5)

An expander for expanding the gaseous working medium;
A condenser for condensing the working medium expanded by the expander;
A pump for pressurizing the working medium condensed in the condenser;
A heater for evaporating at least a part of the working medium pressurized by the pump with heat of the heat source medium;
On the downstream side of the heater, cooling means that cools the working medium in a superheated state at a predetermined temperature or higher in a range that is maintained at a saturation temperature or higher ;
Equipped with a,
The cooling means includes a cooling passage and a cooling valve provided in the cooling passage, and one end of the cooling passage is provided with the condenser, the pump, the heater, and the expander. Connected to a site between the pump and the heater in the circulation channel, and the other end is connected to a site between the heater and the expander in the circulation channel,
During operation, the pump is controlled so that the degree of superheat of the working medium on the downstream side of the heater is within a preset range, while the working medium is in an overheated state and the heater When it is determined that the temperature of the working medium flowing out of the expander and introduced into the expander exceeds the reference temperature, the cooling means opens the cooling valve and the liquid flowing through the cooling passage The working medium cools the working medium in the overheated state using vaporization heat by joining the working medium in the circulating flow path to the working medium in the overheated state . An expander for expanding the gaseous working medium;
A condenser for condensing the working medium expanded by the expander;
A pump for pressurizing the working medium condensed in the condenser;
A heater for evaporating at least a part of the working medium pressurized by the pump with heat of the heat source medium;
On the downstream side of the heater, cooling means that cools the working medium in a superheated state at a predetermined temperature or higher in a range that is maintained at a saturation temperature or higher;
With
The cooling means includes a cooling heat exchanger, a cooling passage, and a cooling valve provided in the cooling passage, and one end portion of the cooling passage includes the condenser, the pump, and the heating Connected to a portion between the pump and the heater in the circulation flow path in which the expander and the expander are provided, and the other end is connected to a portion between the expander and the condenser in the circulation flow path. Connected,
The cooling heat exchanger is disposed on the downstream side of the heater in the circulation channel, and is provided with a working medium channel connected to the circulation channel, and the cooling channel,
During operation, the pump is controlled so that the degree of superheat of the working medium on the downstream side of the heater is within a preset range, while the working medium is in an overheated state and the heater When it is determined that the temperature of the working medium flowing out of the expander and introduced into the expander exceeds a reference temperature, the cooling means opens the cooling valve, and in the cooling heat exchanger, The power generation device that cools the overheated working medium by indirectly exchanging heat between the working medium divided into the cooling passage and the working medium in the circulation passage . The power generation device according to claim 2, wherein the cooling unit cools the overheated working medium using vaporization heat . An expander for expanding the gaseous working medium;
A condenser for condensing the working medium expanded by the expander with a cooling medium supplied from a cooling circuit;
A pump for pressurizing the working medium condensed in the condenser;
A heater for evaporating at least a part of the working medium pressurized by the pump with heat of the heat source medium;
On the downstream side of the heater, cooling means that cools the working medium in a superheated state at a predetermined temperature or higher in a range that is maintained at a saturation temperature or higher;
With
The cooling means includes a cooling heat exchanger, a cooling passage, and a cooling valve provided in the cooling passage,
The cooling passage is connected to a portion of the cooling circuit downstream of the condenser, and the cooling medium that has flowed through the cooling passage is returned to the cooling circuit.
The cooling heat exchanger is disposed on the downstream side of the heater in a circulation channel in which the condenser, the pump, the heater, and the expander are provided, and the cooling heat exchanger includes the circulation flow A working medium flow path connected to the path, and the cooling passage,
During operation, the pump is controlled so that the degree of superheat of the working medium on the downstream side of the heater is within a preset range, while the working medium is in an overheated state and the heater When it is determined that the temperature of the working medium flowing out of the expander and introduced into the expander exceeds a reference temperature, the cooling means opens the cooling valve, and in the cooling heat exchanger, A power generation device that cools a working medium whose cooling medium is in an overheated state . An expander for expanding the gaseous working medium;
A condenser for condensing the working medium expanded by the expander;
A pump for pressurizing the working medium condensed in the condenser;
A heater for evaporating at least a part of the working medium pressurized by the pump with heat of the heat source medium;
On the downstream side of the heater, cooling means for cooling a working medium that is in a superheated state and has a temperature equal to or higher than a predetermined temperature;
With
The cooling means includes a working medium flow path and a cooling flow path, and includes a heat exchanger disposed on the downstream side of the heater, and a decompression means provided in a heat medium circuit connected to the cooling flow path. Have
The depressurization unit is a power generation device that depressurizes the heat medium so that the heat medium is cooled in the heat exchanger when the working medium is in an overheated state and is equal to or higher than a predetermined temperature .

Images