JP2021127712A - Binary power generation unit - Google Patents

Abstract

To provide a binary power generation unit capable of increasing a recovery rate of a working fluid without using an external vacuum pump.SOLUTION: A binary power generation unit 1 comprises: a circulation passage 4 for a working fluid; a receiver 18 connected to the circulation passage 4 to temporarily store the working fluid; a branch flow passage 25 branched from a portion between the pump 8 and an evaporator 10 to introduce the working fluid to the receiver 18; switching means 30 for switching between a normal operation state in which the liquid working fluid discharged from the pump 8 flows toward the evaporator 10 and a recovery operation state in which the liquid working fluid flows into the branch flow passage 25; and an ejector 28 that, when the switching means 30 is in the recovery operation state, sucks the gaseous working fluid existing in the circulation passage 4 by using the liquid working fluid boosted by the pump 8 as a driving fluid.SELECTED DRAWING: Figure 1

Description

The present invention relates to a binary power generation unit.

As shown in FIG. 6, in the binary power generation unit disclosed in Patent Document 1, a liquid feed pump 72, a heat exchanger 73, a steam turbine 74, and a condenser 75 are provided in the circulation path 71 of the working fluid, and the working fluid is provided. The steam turbine 74 is driven to generate power by the circulation of the steam turbine 74. In the binary power generation unit disclosed in Patent Document 1, the recovery line 76 branches from the discharge side of the liquid feed pump 72 in the circulation path 71 of the working fluid. By driving the liquid feed pump 72 with the recovery valve 77 arranged in the recovery line 76 open, the working fluid can be recovered in the recovery tank 78 through the recovery line 76.

Japanese Unexamined Patent Publication No. 2014-190276

In the binary power generation unit disclosed in Patent Document 1, the working fluid in the circulation path 71 is recovered in the recovery tank 78 by using the liquid feed pump 72. Therefore, the working fluid that can be recovered in this power generation unit is only a part of the working fluid liquefied by the condenser 75, and the recovery rate of the working fluid is low. Therefore, if it is desired to increase the recovery rate of the working fluid, the vacuum pump must be connected to the circulation path 71 from the outside and the working fluid must be extracted using the vacuum pump.

The present invention has been made in view of the above-mentioned prior art, and an object of the present invention is to provide a binary power generation unit capable of increasing the recovery rate of working fluid without using an external vacuum pump. be.

In order to achieve the above object, the binary power generation unit according to the present invention includes a circulation path of a working fluid having a pump, an evaporator, an expander and a condenser, and a receiver capable of temporarily storing the working fluid of the circulation path. A branch flow path that branches from a portion of the circulation path between the pump and the evaporator to introduce the working fluid into the receiver, and a liquid working fluid discharged from the pump are directed toward the evaporator. A switching means for switching between a normal operation state in which the fluid flows and a recovery operation state in which the fluid flows into the branch flow path, and a pump provided in the branch flow path when the switching means is in the recovery operation state. An ejector that sucks a gaseous working fluid existing in a portion of the circulation path where the supply of the working fluid from the pump is stopped by the switching means, using the liquid working fluid boosted by I have.

In the binary power generation unit according to the present invention, when the pump operates while the switching means is in the recovery operation state, the pump sucks in the liquid working fluid and discharges the liquid working fluid. The discharged working fluid is pressure-fed to the branch flow path. By this action, a liquid working fluid is sent into the receiver through the branch flow path. At this time, the ejector uses the liquid working fluid boosted by the pump as the driving fluid, and sucks the gaseous working fluid because it exists in the portion of the circulation path where the supply of the working fluid from the pump is stopped by the switching means. .. By the suction action by this ejector, the gaseous working fluid remaining in the circulation path can be sucked, and the gaseous working fluid can also be stored in the receiver. Therefore, the recovery rate of the working fluid can be increased without using an external vacuum pump.

The binary power generation unit switches between a state in which the gaseous working fluid is allowed to flow to the ejector and a state in which the gaseous working fluid is prevented from flowing to the ejector. It may be provided with a switching means.

In this aspect, when the switching means is in the recovery operating state, the suction switching means is switched to a state that allows the gaseous working fluid to flow through the ejector. On the other hand, when the switching means is in the normal operating state, the suction switching means is switched to a state in which the gaseous working fluid is prevented from flowing to the ejector. Therefore, during normal operation, the gaseous working fluid circulating in the circulation path does not flow to the ejector, and the state in which the working fluid circulates in the circulation path can be maintained. On the other hand, during the recovery operation, the gaseous working fluid in the circulation path can be sucked by the ejector.

The binary power generation unit includes a bypass flow path connected to the circulation path so as to bypass the expander, a state in which the gaseous working fluid is allowed to flow through the bypass flow path, and the gaseous state. It may be provided with a bypass switching means for switching between a state in which the working fluid of the above is prevented from flowing through the bypass flow path.

In this embodiment, when the switching means is in the recovery operation state, the bypass switching means is switched to a state in which the gaseous working fluid existing in the circulation path is allowed to flow into the bypass flow path, whereby the working fluid of the working fluid is switched. The working fluid can be recovered without passing through the expander at the time of recovery. Therefore, the gaseous working fluid existing in the circulation path can be recovered more easily.

In the binary power generation unit, the receiver may be arranged between the condenser and the pump in the circulation path.

In this aspect, the portion where the liquid working fluid temporarily accumulates in the circulation path and the portion where the gaseous working fluid is collected can be shared by the receiver.

The binary power generation unit may include a cooling device that cools the working fluid stored in the receiver when the switching means is in the recovery operation state.

In this aspect, when the working fluid is stored in the receiver, it is possible to prevent the temperature of the working fluid accumulated in the receiver from gradually increasing. As a result, it is possible to prevent the working fluid from accumulating in the receiver in the gas state, and it is possible to further prevent the internal pressure of the receiver from gradually increasing and the recovery efficiency from decreasing.

The cooling device may be configured by a vortex cooler. This aspect is particularly effective when installed where compressed air is available. That is, since the vortex school can easily generate cold air using compressed air, it is possible to easily cool the working fluid if compressed air can be obtained.

As described above, according to the present invention, the recovery rate of the working fluid can be increased without using an external vacuum pump.

It is a figure which shows schematicly the binary power generation unit by embodiment of this invention. It is a figure which shows schematic the binary power generation unit by another embodiment of this invention. It is a figure which shows schematic the binary power generation unit by another embodiment of this invention. It is a figure which shows schematic the binary power generation unit by another embodiment of this invention. It is a figure which shows schematic the binary power generation unit by another embodiment of this invention. It is a figure which shows schematicly the conventional binary power generation unit.

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

The binary power generation unit 1 according to the present embodiment is a power generation unit using the Rankine cycle, and includes a pump 8, an evaporator 10, an expander 14, a condenser 16, and a receiver 18 as shown in FIG. ing. The pump 8, the evaporator 10, the expander 14, the condenser 16 and the receiver 18 are connected to the circulation path 4 in which the working fluid circulates in this order. In the binary power generation unit 1 according to the present embodiment, a circulation circuit is configured in which the working fluid flows through the circulation path 4 through the pump 8, the evaporator 10, the expander 14, the condenser 16 and the receiver 18 in this order. As the working fluid, a refrigerant having a boiling point lower than that of water is used.

The pump 8 is located downstream of the condenser 16 in the circulation path 4 (between the evaporator 10 and the condenser 16) and is configured to pressurize the working fluid. The pump 8 pressurizes the liquid working fluid condensed by the condenser 16 to a predetermined pressure and sends it out to the evaporator 10. As the pump 8, a centrifugal pump having an impeller as a rotor, a gear pump in which the rotor is composed of a pair of gears, and the like are used.

The evaporator 10 is located on the downstream side of the pump 8 (between the pump 8 and the expander 14) in the circulation path 4. The evaporator 10 has a working fluid flow path 10a through which the working fluid flows and a heat source fluid flow path 10b through which the heat source fluid flows. In the present embodiment, the evaporator 10 is composed of a shell-and-tube type heat exchanger, the heat source fluid flow path 10b is configured in a hollow shell, and the working fluid flow path 10a is arranged in the shell. It is composed of heat transfer tubes. However, the configuration of the evaporator 10 is not limited to this.

A heat source fluid supplied from an external heat source flows through the heat source fluid flow path 10b. The working fluid flowing through the working fluid flow path 10a exchanges heat with the heat source fluid flowing through the heat source fluid flow path 10b and evaporates. Examples of the heat source fluid include high temperature air and water vapor. Further, when the binary power generation unit 1 is mounted on a ship, scavenging air introduced into the internal combustion engine or exhaust gas discharged from the internal combustion engine may be used as the heat source fluid.

The expander 14 is located on the downstream side of the evaporator 10 (between the evaporator 10 and the condenser 16) in the circulation path 4. The expander 14 has a structure in which a rotor portion (not shown) is arranged in a casing, and the rotor portion is driven by the expansion of the working fluid introduced into the casing. Specifically, in the expander 14, the rotor portion is driven in the process of expanding the gaseous working fluid from the evaporation pressure obtained by the evaporator 10 to the condensation pressure obtained by the condenser 16. A generator 20 is connected to the expander 14 so that the driving force generated in the rotor portion is transmitted. The expansion of the gaseous working fluid in the expander 14 drives the generator 20 to generate electricity.

The condenser 16 is located on the downstream side of the expander 14 (between the expander 14 and the receiver 18) in the circulation path 4. The condenser 16 condenses the gaseous working fluid discharged from the expander 14 into a liquid working fluid. The condenser 16 has a working fluid flow path 16a through which a gaseous working fluid flows, and a cooling fluid flow path 16b through which a cooling fluid such as cooling water flows. Cooling fluids such as cooling water and seawater supplied through the cooling passage 22 flow through the cooling fluid flow path 16b. The working fluid flowing through the working fluid flow path 16a is condensed by exchanging heat with the cooling fluid flowing through the cooling fluid flow path 16b.

The receiver 18 is located on the downstream side of the condenser 16 in the circulation path 4 (between the condenser 16 and the pump 8). The liquid working fluid obtained by the condenser 16 is temporarily stored in the receiver 18.

A branch flow path 25 and a suction flow path 26 are connected to the circulation path 4. The branch flow path 25 branches from a portion of the circulation path 4 between the pump 8 and the evaporator 10 and is connected to the receiver 18. The suction flow path 26 branches from a portion of the circulation path 4 between the expander 14 and the condenser 16, and is connected to an ejector 28 described later.

An ejector 28 is provided in the branch flow path 25. The ejector 28 has a nozzle (not shown) for ejecting a liquid working fluid flowing through the branch flow path 25, and due to the decompression effect of the working fluid by this nozzle, a gaseous operation is performed from the circulation path 4 through the suction flow path 26. It is configured to suck fluid. The working fluid of the liquid gas mixture ejected from the ejector 28 flows into the receiver 18 through the branch flow path 25.

In the binary power generation unit 1, a state in which the working fluid discharged from the pump 8 flows toward the evaporator 10 (normal operation state) and a state in which the working fluid flows into the branch flow path 25 without flowing into the evaporator 10 (recovery operation). A switching means 30 for switching between the operating state and the state) is provided. The switching means 30 includes a first valve 30a arranged on the downstream side of the branch portion of the branch flow path 25 in the circulation path 4, and a second valve 30b arranged on the upstream side of the ejector 28 in the branch flow path 25. Have. When the first valve 30a is opened and the second valve 30b is closed, the normal operation state is set, and when the second valve 30b is opened and the first valve 30a is closed, the recovery operation state is set. The first valve 30a and the second valve 30b are controlled by a signal sent from the controller 32.

The first valve 30a and the second valve 30b are each composed of an on-off valve, but may be composed of one three-way valve (not shown). In this case, the three-way valve is arranged at the branch portion of the branch flow path 25 in the circulation path 4, and communicates with the pump 8 and the evaporator 10 and shuts off between the pump 8 and the ejector 28, and the pump. It is possible to take two states, a recovery operation state in which the 8 and the ejector 28 are communicated with each other and the pump 8 and the evaporator 10 are cut off from each other.

The binary power generation unit 1 has a state in which the gaseous working fluid existing in the circulation path 4 is allowed to be sucked into the ejector 28 (suction allowable state) and a state in which the gaseous working fluid existing in the circulation path 4 is allowed to be sucked into the ejector 28. A suction switching means 34 for switching between a state of preventing suction (a state of preventing suction) and a state of preventing suction is provided. The suction switching means 34 has a third valve 34a arranged in the suction flow path 26 and a fourth valve 34b arranged on the downstream side of the branch portion of the suction flow path 26 in the circulation path 4. In the illustrated example, the fourth valve 34b is arranged between the condenser 16 and the receiver 18 in the circulation path 4. When the third valve 34a is opened and the fourth valve 34b is closed, the suction is allowed, and when the third valve 34a is closed and the fourth valve 34b is opened, the suction is blocked. The third valve 34a and the fourth valve 34b are controlled by a signal sent from the controller 32.

The third valve 34a and the fourth valve 34b are each composed of an on-off valve, but may be composed of one tricuspid valve. In this case, the three-way valve is arranged at the branch portion of the suction flow path 26 in the circulation path 4, allows the working fluid to flow from the circulation path 4 toward the ejector 28, and allows the working fluid to flow from the circulation path 4 to the receiver 18. A suction-allowed state that prevents the working fluid from flowing in, and a suction-blocking state that prevents the working fluid from flowing from the circulation path 4 toward the ejector 28 and allows the working fluid to flow from the circulation path 4 to the receiver 18. Can take two states.

In the illustrated example, valves are arranged in the circulation path 4 and the branch flow path 25 in addition to the valves constituting the switching means 30 or the suction switching means 34. Specifically, the fifth valve 37 is arranged between the receiver 18 and the pump 8 in the circulation path 4, and the sixth valve 38 is arranged on the downstream side of the ejector 28 in the branch flow path 25. These valves 37 and 38 are controlled by a signal sent from the controller 32.

The binary power generation unit 1 is provided with a cooling device 40 for cooling the working fluid stored in the receiver 18. In the present embodiment, the cooling device 40 is arranged so as to blow cold air onto the receiver 18 to cool the receiver 18.

The cooling device 40 is composed of a vortex cooler that generates cold air from compressed air. The vortex schooler has a cylindrical inner chamber (not shown) extending in one direction, and the compressed air introduced into the inner chamber is configured to flow spirally at high speed. A part of the compressed air that flows in a spiral direction is inverted in the axial direction at one end of the inner chamber and flows near the central axis. At this time, since the pressure is low near the central axis, the temperature drops due to expansion, and cold air is blown out from the outlet located at the other end of the inner chamber. An outlet is also formed at one end of the inner chamber, and the remaining compressed air is blown out as hot air from this outlet. An on-off valve 42 is provided in the pipe for introducing compressed air into the cooling device 40. The on-off valve 42 is controlled by a signal sent from the controller 32.

A supply path 44 for supplying a working fluid into the circulation path 4 is connected to the circulation path 4. The supply path 44 is connected to a portion of the circulation path 4 between the receiver 18 and the pump 8. When the supply valve 44a arranged in the supply path 44 is opened and the pump 8 is operated with the supply source of the working fluid connected to the supply path 44, the working fluid can be supplied to the circulation path through the supply path 44. can. The supply path 44 may be omitted.

A discharge path 46 for discharging the working fluid to the outside of the circulation path 4 is connected to the circulation path 4. The discharge path 46 is connected to a portion of the circulation path 4 between the pump 8 and the evaporator 10. When the pump 8 is operated with the discharge valve 46a arranged in the discharge passage 46 open, the working fluid in a liquid state can be discharged to the outside through the discharge passage 46. The discharge path 46 may be omitted.

Here, the operation operation of the binary power generation unit 1 according to the present embodiment will be described. When operating the binary power generation unit 1, the controller 32 opens the first valve 30a, the fourth valve 34b, and the fifth valve 37, and closes the second valve 30b, the third valve 34a, and the sixth valve 38. Further, the controller 32 also keeps the on-off valve 42 of the cooling device 40 closed.

When the pump 8 operates in this state, the liquid working fluid discharged from the pump 8 flows into the working fluid flow path 10a of the evaporator 10 through the circulation path 4. In the evaporator 10, the liquid working fluid is heated by the heat source fluid flowing through the heat source fluid flow path 10b and evaporates to become a gaseous working fluid. The gaseous working fluid is introduced into the expander 14 to drive the rotor section. As a result, the gaseous working fluid expands and the temperature drops. On the other hand, since power is generated by driving the rotor unit, the heat of the heat source fluid can be recovered as electric power.

The gaseous working fluid that has become low temperature and low pressure in the expander 14 flows into the condenser 16. In the condenser 16, the working fluid flowing through the working fluid flow path 16a is cooled by the cooling fluid flowing through the cooling fluid flow path 16b and condensed to become a liquid working fluid. The liquid working fluid flows out of the condenser 16 and is then stored in the receiver 18. The working fluid in the receiver 18 is sucked into the pump 8. Such circulation of the working fluid is performed in the circulation path 4.

Since the binary power generation unit 1 uses packings such as O-rings and bearings, maintenance such as replacement of these members is required. In such a case, a recovery operation is performed in which the working fluid enclosed in the circulation path 4 is accommodated in the receiver 18.

When performing the recovery operation, the controller 32 closes the first valve 30a with the fourth valve 34b open to the extent that the inside of the circulation path 4 becomes saturated vapor pressure and becomes a substantially equilibrium state, and then the fourth valve 30a is performed. The valve 34b is closed, and the second valve 30b, the third valve 34a, the fifth valve 37, and the sixth valve 38 are opened. Further, the controller 32 opens the on-off valve 42 of the cooling device 40. In FIG. 1, the opened valve is shown in white, and the closed valve is shown in black.

When the pump 8 operates in this state, the liquid working fluid discharged from the pump 8 flows into the branch flow path 25 and is introduced into the ejector 28. In the ejector 28, the gaseous working fluid is sucked into the ejector 28 from the circulation path 4 through the suction flow path 26 by the depressurizing action generated when the liquid working fluid is ejected from the nozzle. Then, the liquid working fluid and the gaseous working fluid are stored in the receiver 18 through the branch flow path 25 in a mixed state.

As the gaseous working fluid is introduced into the receiver 18, the temperature inside the receiver 18 may rise and the pressure may increase. Therefore, by blowing the cold air generated by the cooling device 40 onto the receiver 18, the receiver 18 may be heated. It cools the gaseous working fluid inside and promotes condensation. As a result, the pressure inside the receiver 18 is suppressed from rising, and the working fluid is easily accumulated in the receiver 18. When the gaseous working fluid in the circulation path 4 is reduced to the extent that the ejector 28 cannot suck the gaseous working fluid, the pump 8 is stopped and all the valves are closed.

As described above, in the present embodiment, when the pump 8 operates while the switching means 30 is in the recovery operation state, the pump 8 sucks in the liquid working fluid in the receiver 18 and discharges the liquid working fluid. .. The discharged working fluid is pressure-fed to the branch flow path 25. By this action, a liquid working fluid is sent into the receiver 18 through the branch flow path 25. At this time, the ejector 28 uses the working fluid boosted by the pump 8 as the driving fluid, and sucks the working fluid from the portion where the supply of the working fluid from the pump 8 is stopped by the switching means 30. The ejector 28 can suck the gaseous working fluid by the suction action, and the gaseous working fluid can also be stored in the receiver 18. Therefore, the recovery rate of the working fluid can be increased without using an external vacuum pump.

Further, when the switching means 30 is in the recovery operation state, the suction switching means 34 is switched to a state that allows the gaseous working fluid to flow to the ejector 28. On the other hand, when the switching means 30 is in the normal operating state, the suction switching means 34 is switched to a state in which the gaseous working fluid is prevented from flowing to the ejector 28. Therefore, during normal operation, the working fluid circulating in the circulation path 4 does not flow to the ejector 28, and the state in which the working fluid circulates in the circulation path 4 can be maintained. On the other hand, during the recovery operation, the gaseous working fluid in the circulation path 4 can be sucked by the ejector 28.

Further, in the present embodiment, since the cooling device 40 for cooling the working fluid stored in the receiver 18 is provided, the temperature of the working fluid accumulated in the receiver 18 gradually rises when the working fluid is stored in the receiver 18. Can be suppressed. As a result, it is possible to prevent the working fluid from accumulating in the receiver 18 in the gas state, and it is possible to further prevent the internal pressure of the receiver 18 from gradually increasing and the recovery efficiency from decreasing.

Further, in the present embodiment, since the cooling device 40 is composed of a vortex cooler, it is particularly effective when it is installed in a place where compressed air can be obtained. That is, since the vortex school can easily generate cold air using compressed air, it is possible to easily cool the working fluid if it is installed in a place where compressed air can be obtained. The cooling device 40 does not have to be configured by a vortex cooler, and may be configured by, for example, a chiller or the like.

It should be noted that the embodiments disclosed this time are exemplary in all respects and are not considered to be restrictive. The present invention is not limited to the above-described embodiment, and various modifications and improvements can be made without departing from the spirit of the present invention.

For example, in the above-described embodiment, the first to sixth valves 30a, 30b, 34a, 34b, 37, 38 and the on-off valve 42 are controlled to be opened and closed by the controller 32, but the present invention is not limited to this. The first to sixth valves 30a, 30b, 34a, 34b, 37, 38 and the on-off valve 42 may be configured to be manually opened and closed.

In the above embodiment, the suction flow path 26 is configured to branch from the portion between the expander 14 and the condenser 16 in the circulation path 4, but the present invention is not limited to this. For example, the suction flow path 26 may branch from a portion of the circulation path 4 between the evaporator 10 and the expander 14, or may branch from a portion of the circulation path 4 between the condenser 16 and the receiver 18. You may. Further, it may branch from a portion of the circulation path 4 between the first valve 30a and the evaporator 10.

In the above embodiment, the suction flow path 26 is composed of one flow path, but the suction flow path 26 is not limited to this. For example, as shown in FIG. 2, the suction flow path 26 has a configuration including a main flow path 26a connected to the ejector 28 and a plurality of branch flow paths whose downstream ends are connected to the main flow path 26a, respectively. You may. In FIG. 2, as a branch flow path, between the first branch flow path 26b branching from the portion between the evaporator 10 and the expander 14 in the circulation path 4 and the expander 14 and the condenser 16 in the circulation path 4. A configuration is shown in which a second branch flow path 26c branching from the portion of the above and a third branch flow path 26d branching from the portion between the condenser 16 and the receiver 18 in the circulation path 4 are provided. In this configuration, the third valve 34a is arranged in each branch flow path 26b to 26d. The configuration is not limited to the configuration having three branch flow paths, and the configuration may have any two branch flow paths. The connection portions of the branch flow paths 26b, 26c, and 26d in the circulation path 4 are all portions where the supply of the working fluid from the pump 8 is stopped by the switching means 30. The branch flow path (suction flow path 26) may be connected to a portion of the circulation path 4 between the first valve 30a and the evaporator 10. This portion is also a portion where the supply of the working fluid from the pump 8 is stopped by the switching means 30.

As shown in FIG. 3, a bypass flow path 48 may be connected to the circulation path 4 so as to bypass the expander 14. One end of the bypass flow path 48 is connected to a portion of the circulation path 4 between the evaporator 10 and the expander 14, and the other end of the bypass flow path 48 is the expander 14 and the condenser 16 in the circulation path 4. It is connected to the part between and. The other end of the bypass flow path 48 is connected to the circulation path 4 on the upstream side of the branch portion of the suction flow path 26.

A bypass valve 50 as a bypass switching means is arranged in the bypass flow path 48. When the bypass valve 50 is opened, the working fluid existing in the circulation path 4 is allowed to flow into the bypass flow path 48. When the bypass valve 50 is closed, the working fluid existing in the circulation path 4 is prevented from flowing into the bypass flow path 48. The controller 32 opens the bypass valve 50 when the switching means 30 is in the recovery operation state. As a result, the working fluid can be recovered without passing through the expander 14 when the working fluid is recovered. Therefore, the gaseous working fluid existing in the circulation path 4 can be recovered more easily.

In the above embodiment, the cooling device 40 is configured to cool the receiver 18, but the present invention is not limited to this. For example, as shown in FIG. 4, the cooling device 40 may be configured to cool the branch flow path 25. Even in this case, the cooling device 40 is configured to cool the working fluid stored in the receiver 18. In the example shown in FIG. 4, the cooling device 40 shows a configuration in which the working fluid is cooled on the downstream side of the ejector 28 in the branch flow path 25, but the cooling device 40 is on the upstream side of the ejector 28 in the branch flow path 25. It may be configured to cool the working fluid. In the branch flow path 25, the portion to which the cooling device 40 is attached may be formed by a pipe with fins. In this case, it may be an inner fin or an outer fin. Since the cooling efficiency is higher when the receiver 18 itself is cooled, the cooling device 40 is preferably configured to cool the receiver 18 itself. Further, the cooling device 40 may be omitted.

In the above embodiment, one receiver 18 is connected to the circulation path 4, but two or more receivers may be connected to the circulation path 4. Further, the receiver 18 may be detachably connected to the circulation path 4.

Further, in the above-described embodiment, the configuration is provided with one branch flow path 25 provided with the ejector 28, but a configuration including two or more similar branch flow paths may be provided.

Further, as shown in FIG. 5, in addition to the receiver 18 connected to the circulation path 4, the receiver 55 connected to the branch flow path 25 may be provided. In this case, the receiver 55 may be arranged above the receiver 18 so that the working fluid in the receiver 55 flows into the receiver 18 by gravity. The receiver 55 may be detachably connected to the branch flow path 25. The branch flow path 25 may be provided with an on-off valve 57 between the receiver 55 and the receiver 18. The on-off valve 57 is opened when the working fluid in the receiver 55 flows into the receiver 18, and is closed at other times.

In the form of FIG. 5, the receiver 18 may be omitted. In this configuration, one end of the branch flow path 25 is connected to a portion of the circulation path 4 between the pump 8 and the evaporator 10, while the other end of the branch flow path 25 is condensed in the circulation path 4. The configuration is connected to a portion between the vessel 16 and the pump 8. Even in this configuration, the working fluid is temporarily stored in the receiver 55. In this case, the on-off valve 57 is omitted. Although the cooling device 40 is not shown in FIG. 5, the cooling device 40 may be provided in this form as well.

In the embodiment shown in FIGS. 1 to 5, the branch flow path 25 is configured to branch from the portion between the pump 8 and the evaporator 10 in the circulation path 4 and connect to the receiver 18, but the present invention is not limited to this. For example, the branch flow path 25 may be configured to introduce a working fluid into the receiver 18 by connecting to a portion between the condenser 16 and the receiver 18 in the circulation path 4 instead of the configuration connected to the receiver 18. good. Further, the branch flow path 25, the ejector 28 and the suction flow path 26 may be detachable from the circulation path 4.

1: Binary power generation unit 4: Circulation path 8: Pump 10: Evaporator 14: Expander 16: Condenser 18: Receiver 25: Branch flow path 28: Ejector 30: Switching means 34: Suction switching means 40: Cooling device 48: Bypass flow path 50: Bypass valve 55: Receiver

Claims (6)

A working fluid circulation path with a pump, evaporator, expander and condenser,
With a receiver that can temporarily store the working fluid of the circulation path,
A branch flow path that branches from a portion of the circulation path between the pump and the evaporator to introduce a working fluid into the receiver.
A switching means for switching between a normal operation state in which the liquid working fluid discharged from the pump flows toward the evaporator and a recovery operation state in which the liquid working fluid flows into the branch flow path.
When the switching means provided in the branch flow path is in the recovery operation state, the liquid working fluid boosted by the pump is used as a driving fluid, and the switching means from the pump in the circulation path. A binary power generation unit equipped with an ejector that sucks the gaseous working fluid existing in the part where the supply of the working fluid is stopped. A suction switching means for switching between a state in which the gaseous working fluid is allowed to flow to the ejector and a state in which the gaseous working fluid is prevented from flowing to the ejector is provided. The binary power generation unit according to claim 1. A bypass flow path connected to the circulation path so as to bypass the expander,
Bypass switching means for switching between a state in which the gaseous working fluid is allowed to flow through the bypass flow path and a state in which the gaseous working fluid is prevented from flowing through the bypass flow path. The binary power generation unit according to claim 1, further comprising. The binary power generation unit according to any one of claims 1 to 3, wherein the receiver is arranged between the condenser and the pump in the circulation path. The binary power generation unit according to any one of claims 1 to 4, further comprising a cooling device for cooling the working fluid stored in the receiver when the switching means is in the recovery operation state. The binary power generation unit according to claim 5, wherein the cooling device is composed of a vortex cooler.

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