JP2016014329A - Thermal energy recovery device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal energy recovery device which enables improvement of the power recovery efficiency while cooling an electric motor of a pump.SOLUTION: A thermal energy recovery device includes: an evaporator (10); an expander (14); a power recovery machine(16); a condenser (18); a circulation passage (30); a pump (20) which is provided in the circulation passage (30) and branches a part of a working medium flowing thereinto from the circulation passage (30) as a branch medium; and a branch passage (32) for flowing the branch medium. The pump (20) includes: an electric motor (24); a first passage (26) connected with the circulation passage (30); and a second passage (28) which branches a part of the working medium flowing in the first passage (26) as a branch medium and is disposed so that the electric motor (24) is cooled by the branch medium flowing therein. The branch passage (32) connects the second passage (28) with a middle part of the expander (14).

Description

  The present invention relates to a thermal energy recovery device.

  2. Description of the Related Art Conventionally, a thermal energy recovery device that recovers power from exhaust heat of various facilities such as factories is known. For example, Patent Document 1 discloses an evaporator, an expander into which a working medium flowing out from the evaporator flows, a generator main body connected to the expander, and a condenser for condensing the working medium flowing out from the expander. A power generation system is disclosed that includes a circulation pump that sends a working medium flowing out of a condenser to an evaporator, a circulation pipe through which the working medium circulates, and a heat medium line. In this power generation system, a so-called reverse circulation type pump is used as a circulation pump. Specifically, the circulation pump has an electric motor, and after cooling the electric motor with a part of the liquid working medium flowing into the circulation pump from the circulation pipe, the working medium is discharged as a heat medium to the heat medium line. To do. The heat medium line connects a portion between the expansion pump and the condenser in the circulation pump and the circulation pipe. The heat medium line is configured to pass through a preheating heat exchanger provided in a portion of the circulation pipe between the circulation pump and the evaporator. For this reason, the heat medium (working medium after receiving heat from the electric motor) discharged from the circulation pump to the heat medium line gives heat to the working medium discharged from the circulation pump in the preheating heat exchanger.

JP 2013-019303 A

  In the power generation system disclosed in Patent Document 1, when the heat medium cools the electric motor of the circulation pump, the heat energy received from the electric motor is applied to the working medium, so that the exhaust heat of the electric motor is effectively recovered. However, this system has room for improvement in power recovery efficiency.

  An object of the present invention is to provide a thermal energy recovery device capable of improving power recovery efficiency while cooling an electric motor of a pump.

  As means for solving the above problems, the present invention includes an evaporator for evaporating a working medium, an expander into which the working medium flowing out from the evaporator flows, a power recovery machine connected to the expander, and the expansion A condenser for condensing the working medium flowing out from the machine, a circulation channel connecting the evaporator, the expander and the condenser, and a portion of the circulation channel between the condenser and the evaporator A pump capable of diverting a part of the working medium flowing in from the circulation flow path as a diversion medium, and a diversion flow path for flowing the diversion medium diverted by the pump out of the working medium And the pump splits a part of the working medium flowing through the first flow path as the flow dividing medium and flows through the electric motor, a first flow path connected to the circulation flow path Depending on the medium And a second flow path arranged so that the electric motor is cooled, and the shunt flow path connects the second flow path and a middle portion of the expander. I will provide a.

  In the present invention, in addition to the working medium discharged from the pump to the circulation flow path through the first flow path, the flow dividing medium (working medium after receiving heat from the electric motor) flowing out from the pump to the flow dividing flow path through the second flow path is also included. Since it flows into the expander, it flows into the expander compared to the conventional case (when only the working medium discharged from the pump into the circulation flow path flows into the expander and the diverted medium divided by the pump does not flow into the expander). As the total amount of working medium increases, the heat received from the motor is also recovered. Therefore, the power recovery rate in the power recovery machine is improved. Here, although the pressure of the flow dividing medium flowing out from the second flow path to the flow dividing flow path is smaller than the pressure of the working medium discharged from the first flow path to the circulation flow path, the flow dividing flow path is the middle part of the expander. That is, since the working medium is connected to a portion where the pressure of the working medium is lower than the inlet of the expander, inflow of the diverted medium flowing out from the second flow path to the diverted flow path into the expander is allowed.

  In this case, it is preferable to further include a heater that is provided in the diversion flow path and heats the diversion medium.

  In this aspect, before the diversion medium flows into the expander, the diversion medium can be more reliably changed to the gas phase in the heater. Therefore, the drive of the expander is stabilized.

  Furthermore, in this case, the part between the pump and the heater in the diversion channel and the part between the expander and the condenser in the circulation channel or the condenser are connected. It is preferable to further include a branch channel and a flow rate adjustment valve capable of adjusting a flow rate of the branch medium that branches into the branch channel out of the branch medium flowing out from the second channel to the branch channel.

  If it does in this way, it will become possible to make a gaseous-phase branching medium flow into an expander, cooling an electric motor effectively. Specifically, when it is attempted to secure the flow rate of the diversion medium that can sufficiently cool the electric motor, the flow rate of the diversion medium that flows out to the diversion flow path through the second flow path may increase. In this case, when the branch flow path and the flow rate adjusting valve are not provided, the entire amount of the flow dividing medium that has flowed out to the flow dividing flow path flows into the heater. There is a risk of flowing into the expander in a gas-liquid two-phase state. On the other hand, in the present invention, since the branch flow path and the flow rate adjustment valve are provided, even when the outflow amount of the flow dividing medium to the flow dividing flow path increases, the flow dividing medium is changed to the gas phase in the heater. Thus, it becomes possible to adjust the flow rate of the diversion medium to be diverted to the branch flow path. For this reason, it is not necessary to limit the flow rate of the diversion medium necessary for cooling the electric motor. For example, by gradually increasing the expander side opening from the state where the expander side opening of the flow rate adjustment valve is zero, the heater adjusts so that the flow splitting medium in a gas phase at the heater flows into the heater. To do. Therefore, both the cooling of the electric motor and the flow of the gas-phase branching medium into the expander can be achieved.

  In addition, it is preferable to further include a control unit that adjusts the opening degree of the flow rate adjusting valve so that the degree of superheat of the flow dividing medium flowing into the expander is within a certain range.

  In this way, the diversion medium flows into the expander with a degree of superheat within a certain range, so that the drive of the expander becomes more stable.

  Moreover, in this invention, it is preferable to further provide the pressure regulation valve which is provided in the site | part between the said pump and the said heater among the said shunt flow paths, and can adjust the pressure of the said shunt medium.

  If it does in this way, it will become possible to adjust the pressure of a diversion medium to the pressure which is easy to flow into the middle stage part of an expander. For example, by gradually increasing the opening degree from a state where the opening degree (set pressure) of the pressure adjusting valve is minimum, the pressure of the flow dividing medium is adjusted to a pressure that easily flows into the middle stage of the expander.

  Further, in the present invention, an oil recovery machine that is provided in a portion of the circulation channel between the evaporator and the expander, and that recovers oil contained in the working medium, and the oil recovery machine An oil supply flow path for supplying the recovered oil to the expander, and the heater is connected to the oil supply flow path so that the diversion medium is heated by the oil It is preferable.

  If it does in this way, it will become possible to heat a diversion medium by using effectively exhaust heat of oil collected with an oil recovery machine. Further, since the viscosity of the oil is increased by being cooled by the flow dividing medium in the heater, the occurrence of so-called oil film breakage in the expander is suppressed (the lubricating performance is improved).

  Moreover, in this invention, it is preferable to further provide the heat exchanger provided in the site | part between the said pump and the said heater among the said shunt flow paths. In this case, the heat exchanger is a medium for heating the diversion medium flow path through which the diversion medium flows and the diversion medium flow path through the diversion medium flow path, and exchanges heat with the working medium in the evaporator. And a heating medium flow path through which a subsequent heating medium flows.

  If it does in this way, it will become possible to further heat a diversion medium by recovering the remainder of the heat energy of a heating medium after exchanging heat with a working medium with an evaporator.

  Alternatively, the heat exchanger is a flow dividing medium flow path through which the flow dividing medium flows, and a medium for heating the flow dividing medium flowing through the flow dividing medium flow path, after flowing out of the expander and to the condenser. And a heating medium flow path through which the working medium before flowing in may flow.

  If it does in this way, it will become possible to further heat a shunt medium by collect | recovering the thermal energy of a working medium after power is collect | recovered by an expander (after temperature falls).

  In the present invention, the expander includes a first expansion portion that expands the working medium, and a second expansion portion that further expands the working medium after being expanded in the first expansion portion, The shunt flow path is preferably connected between the first expansion portion and the second expansion portion, which are the middle stage portions.

  As described above, according to the present invention, it is possible to provide a thermal energy recovery device capable of improving power recovery efficiency while cooling a pump motor.

It is a figure which shows the outline of a structure of the thermal energy recovery apparatus of 1st embodiment of this invention. It is a flowchart which shows the control content of the control part of the thermal energy recovery apparatus of FIG. It is a figure which shows the outline of a structure of the thermal energy recovery apparatus of 2nd embodiment of this invention.

  Preferred embodiments of the present invention will be described below with reference to the drawings.

(First embodiment)
A thermal energy recovery apparatus according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2.

  As shown in FIG. 1, the thermal energy recovery apparatus includes an evaporator 10, an oil recovery machine 12, an expander 14, a power recovery machine 16, a condenser 18, a pump 20, an evaporator 10, an oil A circulation channel 30, a diversion channel 32, a heater 34, and a branch channel 36 that connect the recovery machine 12, the expander 14, the condenser 18, and the pump 20 in this order are provided.

  The evaporator 10 evaporates the liquid working medium into a gaseous working medium. Specifically, the evaporator 10 has a working medium flow path 10a through which a working medium flows and a heating medium flow path 10b through which a heating medium supplied from an external heat source flows. The liquid working medium flowing into the working medium flow path 10a evaporates by exchanging heat with the heating medium flowing into the heating medium flow path 10b. Examples of the heating medium supplied to the evaporator 10 include hot water and high-temperature gas discharged from a factory or the like.

  The oil recovery machine 12 is provided at the downstream side of the evaporator 10 in the circulation channel 30. The oil recovery machine 12 separates oil contained in the working medium. The oil recovered by the oil recovery machine 12 is supplied to the expander 14 through an oil supply channel 13 that connects the oil recovery machine 12 and the expander 14.

  The expander 14 is provided in the downstream portion of the oil recovery machine 12 in the circulation flow path 30. In the present embodiment, a positive displacement screw expander having a rotor that is rotationally driven by the expansion energy of the gaseous working medium flowing out from the oil recovery machine 12 is used as the expander 14. Specifically, the expander 14 includes a first expansion portion 14a including a pair of male and female screw rotors, a second expansion portion 14b including a pair of male and female screw rotors provided on the downstream side of the first expansion portion 14a, and And a casing 14c that accommodates the expansion portions 14a and 14b.

  The first expansion portion 14a is rotationally driven by the expansion energy of the working medium that has flowed into the casing 14c from the circulation flow path 30. The second expansion portion 14b is rotationally driven by the expansion energy of the working medium whose pressure has been reduced by driving the first expansion portion 14a. The working medium whose pressure has been reduced by driving the second expansion portion 14b is discharged to the circulation passage 30 from the discharge port formed in the casing 14c. The expander 14 is not limited to a positive displacement screw expander, but may be a centrifugal type or a scroll type.

  The power recovery machine 16 is connected to the expander 14. In the present embodiment, a power generator is used as the power recovery machine 16. The power recovery machine 16 has a rotating shaft connected to one of a pair of screw rotors of the expander 14. The power recovery machine 16 generates electric power when the rotating shaft rotates with the rotation of the screw rotor. In addition to the generator, a compressor or the like may be used as the power recovery machine 16.

  The condenser 18 is provided in a portion of the circulation channel 30 on the downstream side of the expander 14. The condenser 18 condenses (liquefies) the working medium flowing out of the expander 14 by cooling with a cooling medium (cooling water or the like).

  The pump 20 is provided at a site downstream of the condenser 18 in the circulation channel 30 (a site between the condenser 18 and the evaporator 10). The pump 20 can divert part of the working medium flowing in from the circulation flow path 30 as a diversion medium. Specifically, the pump 20 includes a pressurization unit (an impeller in this embodiment) 22 that pressurizes the working medium, an electric motor 24 for driving the pressurization unit 22, and a first flow connected to the circulation flow path 30. It has a channel 26 and a second channel 28 branched from the first channel 26.

  The second flow path 28 diverts a part of the working medium flowing through the first flow path 26 as the diversion medium. The second flow path 28 is disposed at a position where the electric motor 24 is cooled by the flow dividing medium flowing in the second flow path 28. In other words, the shunt medium receives heat from the motor 24 by exchanging heat with the motor 24 in the process of passing through the second flow path 28.

  The diversion flow path 32 is a flow path for flowing the diversion medium divided by the pump 20 out of the working medium. The diversion flow path 32 connects the second flow path 28 of the pump 20 and the middle stage of the expander 14 (a portion between the first expansion section 14a and the second expansion section 14b).

  The heater 34 is provided in the diversion channel 32. The heater 34 includes a flow dividing medium flow path 34a through which the flow dividing medium flows, and a heating medium flow path 34b through which the heating medium that heats the flow dividing medium flowing through the flow dividing medium flow path 34a. In the present embodiment, the heating medium flow path 34 b is connected to the oil supply flow path 13. That is, in the present embodiment, oil recovered by the oil recovery machine 12 is used as a medium for heating the diversion medium. This oil is heated together with the working medium in the evaporator 10.

  The branch flow path 36 is a flow path that branches a part of the diversion medium that has flowed out from the second flow path 28 of the pump 20 to the diversion flow path 32. Specifically, the branch flow path 36 connects a portion of the shunt flow passage 32 between the pump 20 and the heater 34 and a portion of the circulation flow passage 30 between the expander 14 and the condenser 18. ing. The branch flow path 36 may connect the condenser 18 to a portion of the shunt flow path 32 between the pump 20 and the heater 34.

  In the present embodiment, the degree of superheat Tα of the diversion medium flowing into the expander 14 (the diversion medium flowing through the portion of the diversion flow path 32 between the heater 34 and the expander 14) is within a certain range. The flow rate of the diversion medium flowing into the expander 14 can be adjusted. Specifically, the thermal energy recovery device further includes a flow rate adjustment valve V1, a pressure sensor 38, a temperature sensor 39, and a control unit 40.

  The flow rate adjusting valve V <b> 1 is provided at a connection portion between the branch flow path 32 and the branch flow path 36. The flow rate adjusting valve V1 controls the flow rate of the flow dividing medium that flows into the branch flow channel 36 out of the flow dividing medium that flows out from the second flow channel 28 of the pump 20 into the flow dividing flow channel 32 (the flow rate of the flow dividing medium that flows into the heater 34). It is adjustable. For example, by increasing the expander side opening of the flow rate adjusting valve V1, the inflow amount of the diversion medium into the expander 14 increases and the inflow amount of the diversion medium into the branch flow path 36 decreases.

  The pressure sensor 38 and the temperature sensor 39 are provided in a part of the shunt flow path 32 between the heater 34 and the expander 14.

  The control unit 40 calculates the superheat degree Tα based on the detection value P1 of the pressure sensor 38 and the detection value T1 of the temperature sensor 39, and controls the flow rate adjustment valve V1 so that the superheat degree Tα falls within a certain range. Adjust the opening (expansion side opening). More preferably, the control unit 40 adjusts the opening degree of the flow rate adjustment valve V1 so that the superheat degree Tα becomes a preset superheat degree T0.

  Further, in the present embodiment, the pressure adjusting valve V <b> 2 is provided in the branch flow path 32. More specifically, the pressure regulating valve V <b> 2 is provided in a portion between the flow regulating valve V <b> 1 and the heater 34 in the branch flow path 32. The pressure regulating valve V2 is a valve (pressure reducing valve) capable of adjusting the pressure of the flow dividing medium flowing out downstream of the pressure regulating valve V2. The pressure of the flow dividing medium flowing out from the pressure adjustment valve V2 is adjusted by adjusting the opening degree (set pressure) of the pressure adjustment valve V2. The pressure adjusting valve V2 is provided to adjust the pressure of the flow dividing medium to a pressure that easily flows into the middle stage of the expander 14 (a portion between the first expansion portion 14a and the second expansion portion 14b). . Specifically, since the pressure of the flow dividing medium that can flow into the middle stage of the expander 14 is limited within a specific range, it is easy to adjust the pressure of the flow dividing medium within the specific range. A pressure regulating valve V2 is provided.

  The control unit 40 also adjusts the opening (set pressure) of the pressure regulating valve V2 so that the detection value P1 of the pressure sensor 38 falls within a specific pressure range. More preferably, the control part 40 adjusts the opening degree of the pressure regulating valve V2 so that the detection value P1 becomes the preset set pressure P0. Here, the set pressure P0 is set to a value equal to or higher than the pressure of the working medium in the middle stage of the expander 14.

  Furthermore, the thermal energy recovery device of the present embodiment includes a heat exchanger 50 provided in the diversion channel 32, a heating medium discharge channel 52 through which the heating medium after heat exchange with the working medium in the evaporator 10 flows, It has more.

  The heat exchanger 50 is provided in the part between the heater 34 and the pressure regulating valve V2 in the shunt flow path 32. The heat exchanger 50 has a flow dividing medium flow path 50a through which the flow dividing medium flows and a heating medium flow path 50b through which a heating medium that heats the flow dividing medium flowing through the flow dividing medium flow path 50a flows. In the present embodiment, the heating medium flow path 50 b is connected to the heating medium discharge flow path 52.

  Here, specific control contents of the control unit 40 will be described with reference to FIG.

  First, during startup of the pump 20 (during startup of the thermal energy recovery device), the flow rate adjustment valve V1 and the pressure adjustment valve V2 are set to the initial state. The initial state refers to a state where the expander side opening of the flow regulating valve V1 is zero and the opening of the pressure regulating valve V2 is minimum.

  Then, the control unit 40 calculates the superheat degree Tα based on the detection value P1 of the pressure sensor 38 and the detection value T1 of the temperature sensor 39 (step S11), and whether the superheat degree Tα is larger than the set superheat degree T0. It is determined whether or not (step S12).

  As a result, when the superheat degree Tα is larger than the set superheat degree T0 (YES in step S12), the control unit 40 opens the flow rate adjustment valve V1 on the expander side in order to increase the inflow amount of the diversion medium to the heater 34. The degree is increased (step S13). On the other hand, when the superheat degree Tα is equal to or less than the set superheat degree T0 (NO in step S12), the control unit 40 determines whether or not the superheat degree Tα is smaller than the set superheat degree T0 (step S14).

  As a result, when the degree of superheat Tα is smaller than the set degree of superheat T0 (YES in step S14), the control unit 40 opens the expander side of the flow rate adjustment valve V1 in order to reduce the inflow amount of the diversion medium into the heater 34. The degree is lowered (step S15).

  And the control part 40 determines whether superheat degree T (alpha) is equal to setting superheat degree T0 after step S13 or step S15 (step S16). As a result, when the superheat degree Tα is not equal to the set superheat degree T0 (NO in step S16), the process returns to step S12. On the other hand, when the superheat degree Tα is equal to the set superheat degree T0 (YES in step S16) and NO in step S14 (when the superheat degree Tα is equal to the set superheat degree T0), the control unit 40 is controlled by the pressure sensor 38. It is determined whether or not the detected value P1 is smaller than the set pressure P0 (step S17).

  As a result, when the detected value P1 is smaller than the set pressure P0 (YES in step S17), the control unit 40 increases the pressure of the diversion medium flowing into the middle stage of the expander 14, that is, the diversion medium expander. 14 to increase the opening (set pressure) of the pressure regulating valve V2 (step S18). On the other hand, when the detected value P1 is equal to or higher than the set pressure P0 (NO in step S17), the control unit 40 determines whether or not the detected value P1 is larger than the set pressure P0 (step S19).

  As a result, when the detected value P1 is larger than the set pressure P0 (YES in step S19), the controller 40 opens the opening of the pressure regulating valve V2 in order to reduce the pressure of the diversion medium flowing into the middle stage of the expander 14. (Step S20).

  Then, after step S18 or step S20, the control unit 40 determines whether or not the detected value P1 is equal to the set pressure P0 (step S21). As a result, when the detected value P1 is not equal to the set pressure P0 (NO in step S21), the process returns to step S17. On the other hand, when the detected value P1 is equal to the set pressure P0 (YES in step S21) and NO in step S19 (when the detected value P1 is equal to the set pressure P0), the process returns to step S11. In this way, the superheat degree Tα and the detection value P1 are controlled to be constant.

  As described above, in the thermal energy recovery device according to the present embodiment, in addition to the working medium discharged from the pump 20 through the first flow path 26 to the circulation flow path 30, the shunt flow path 32 from the pump 20 through the second flow path 28. Since the diverted medium (working medium after receiving heat from the electric motor 24) also flows into the expander 14, only the working medium discharged from the pump to the circulation flow path flows into the expander. The total amount of the working medium flowing into the expander 14 is increased as compared with the case where the divided flow medium does not flow into the expander), and the heat received from the electric motor 24 is also recovered. Therefore, the power recovery rate in the power recovery machine 16 is improved. Here, although the pressure of the flow dividing medium flowing out from the second flow path 28 to the flow dividing flow path 32 is smaller than the pressure of the working medium discharged from the first flow path 26 to the circulation flow path 30, Since it is connected to the middle part of the expander 14, that is, the portion where the pressure of the working medium is lower than the inlet of the expander 14, the expander of the diversion medium flowing out from the second flow path 28 to the diversion flow path 32. Inflow to 14 is allowed.

  Further, in the present embodiment, since the heater 34 is provided in the diversion flow path 32, the diversion medium can be more reliably changed to the gas phase in the heater 34 before the diversion medium flows into the expander 14. . Therefore, the drive of the expander 14 is stabilized.

  Further, in the present embodiment, since the branch flow path 36 and the flow rate adjustment valve V1 are provided, it is possible to allow the gas-phase shunt medium to flow into the expander 14 while the motor 24 is effectively cooled. Specifically, if the flow rate of the flow dividing medium that can sufficiently cool the electric motor 24 is secured, the flow rate of the flow dividing medium that flows out to the flow dividing flow path 32 through the second flow path 28 may increase. In this case, if the branch flow path 36 and the flow rate adjustment valve V1 are not provided, the entire amount of the flow dividing medium that has flowed out to the flow dividing flow path 32 flows into the heater 34. There is a risk of flowing into the expander 14 in a gas-liquid two-phase state without becoming a phase. On the other hand, in this embodiment, since the branch flow path 36 and the flow rate adjusting valve V1 are provided, even when the outflow amount of the diversion medium to the diversion flow path 32 increases, It is possible to adjust the flow rate of the diversion medium to be diverted to the branch channel 36 so that the medium becomes a gas phase. The opening degree of the flow rate adjusting valve V1 is adjusted by the control unit 40.

  Further, in the present embodiment, the control unit 40 adjusts the expander side opening of the flow rate adjustment valve V1 so that the superheat degree Tα of the flow dividing medium flowing into the expander 14 becomes the set superheat degree T0. Therefore, the drive of the expander 14 becomes more stable.

  Further, in the present embodiment, since the pressure adjusting valve V2 is provided in the diversion channel 32, the pressure of the diversion medium can be adjusted to a pressure that easily flows into the middle stage of the expander 14. The opening degree of the pressure regulating valve V2 is adjusted by the control unit 40.

  Moreover, in the said embodiment, since the heating-medium flow path 34b of the heater 34 is connected to the oil supply flow path 13, by using effectively the waste heat of the oil collect | recovered with the oil recovery machine 12, it is a shunt medium. Can be heated. Furthermore, since the viscosity of the oil is increased by being cooled by the flow dividing medium in the heater 34, the occurrence of so-called oil film breakage in the expander 14 is suppressed (the lubrication performance is improved).

  In the present embodiment, the heating medium flow path 50 b of the heat exchanger 50 provided with the diversion flow path 32 is connected to the heating medium discharge flow path 52. Therefore, it becomes possible to further heat the flow-dividing medium by effectively recovering the remaining heat energy of the heating medium after heat exchange with the working medium in the evaporator 10.

(Second embodiment)
A thermal energy recovery apparatus according to a second embodiment of the present invention will be described with reference to FIG. In the second embodiment, only the parts different from the first embodiment will be described, and the description of the same structure, operation, and effect as in the first embodiment will be omitted.

  In this embodiment, the connection destination of the heating medium flow path 50b of the heat exchanger 50 is different from that of the first embodiment. Specifically, the heating medium flow path 50 b of the present embodiment is connected to a portion of the circulation flow path 30 that is downstream of the expander 14 and upstream of the connection portion between the circulation flow path 30 and the branch flow path 36. Has been. That is, in this embodiment, the working medium after flowing out of the expander 14 is used as a medium for heating the diversion medium in the heat exchanger 50.

  As described above, in the present embodiment, before the power is recovered by the heater 34 by effectively recovering the thermal energy of the working medium after the power is recovered by the expander 14 (after the temperature is lowered). In addition, it becomes possible to further heat the diversion medium.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and further includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

  For example, in each of the above-described embodiments, an example in which the heating medium flow path 34b of the heater 34 is connected to the oil supply flow path 13 (an example in which the diversion medium is heated by oil) is shown. It may be heated by a heating medium other than the above (such as the same heating medium as that supplied to the evaporator 10).

  Further, the control unit 40 adjusts the opening degree of the flow rate adjustment valve V1 so that the degree of superheat Tα falls within a certain range, and sets the opening degree of the pressure adjustment valve V2 so that the detected value P1 falls within a specific pressure range. You may adjust. In this case, the control unit 40 increases the opening degree of the flow rate adjustment valve V1 when the degree of superheat Tα is larger than the upper limit value in a certain range, and adjusts the flow rate when the degree of superheat Tα is smaller than the lower limit value in a certain range. Decrease the opening of the valve V1. Thereafter, when the detected value P1 is smaller than the lower limit value of the specific pressure range, the control unit 40 increases the opening of the pressure regulating valve V2, and when the detected value P1 is larger than the upper limit value of the specific pressure range, Lower the opening of the regulating valve V2.

  Moreover, in each said embodiment, the heater 34 and the heat exchanger 50 may be abbreviate | omitted. Further, the branch flow path 36, the flow rate adjustment valve V1, the pressure adjustment valve V2, the pressure sensor 38, the temperature sensor 39, and the control unit 40 may be omitted.

DESCRIPTION OF SYMBOLS 10 Evaporator 12 Oil recovery machine 13 Oil supply flow path 14 Expander 14a First expansion part 14b Second expansion part 16 Power recovery machine (generator)
DESCRIPTION OF SYMBOLS 18 Condenser 20 Pump 22 Pressurization part 24 Electric motor 26 1st flow path 28 2nd flow path 30 Circulation flow path 32 Split flow path 34 Heater 34a Split flow medium flow path 34b Heating medium flow path 36 Branch flow path 38 Pressure sensor 39 Temperature Sensor 40 Control unit 50 Heat exchanger 50a Dividing medium flow path 50b Heating medium flow path 52 Heating medium discharge flow path V1 Flow rate adjusting valve V2 Pressure adjusting valve

Claims (9)

An evaporator for evaporating the working medium;
An expander into which the working medium flowing out of the evaporator flows;
A power recovery machine connected to the expander;
A condenser for condensing the working medium flowing out of the expander;
A circulation flow path connecting the evaporator, the expander and the condenser;
A pump that is provided in a portion of the circulation channel between the condenser and the evaporator, and is capable of diverting a part of the working medium flowing in from the circulation channel as a branch medium;
A diversion channel for flowing the diversion medium diverted by the pump among the working medium,
The pump has an electric motor, a first flow path connected to the circulation flow path, a part of the working medium flowing through the first flow path as a diversion medium, and the electric motor by the diversion medium flowing through the inside. A second flow path arranged to be cooled,
The said shunt flow path is a thermal energy recovery apparatus which has connected the said 2nd flow path and the middle step part of the said expander. The thermal energy recovery device according to claim 1,
The thermal energy recovery apparatus further provided with the heater provided in the said shunt flow path for heating the said shunt medium. The thermal energy recovery device according to claim 2,
A portion between the pump and the heater in the diversion channel, a portion between the expander and the condenser in the circulation channel, or a branch channel connecting the condenser,
A thermal energy recovery device further comprising: a flow rate adjustment valve capable of adjusting a flow rate of the flow dividing medium that flows into the branch flow channel among the flow divided media that have flowed out of the second flow channel into the flow dividing flow channel. The claim is the thermal energy recovery device according to claim 3,
A thermal energy recovery device further comprising a control unit that adjusts an opening degree of the flow rate adjustment valve so that a degree of superheat of the flow-dividing medium flowing into the expander is within a certain range. In the thermal energy recovery device according to any one of claims 2 to 4,
A thermal energy recovery device, further comprising a pressure adjusting valve provided in a portion between the pump and the heater in the branch flow path and capable of adjusting a pressure of the flow dividing medium. In the thermal energy recovery device according to any one of claims 2 to 5,
An oil recovery machine that is provided in a portion of the circulation channel between the evaporator and the expander, and that recovers oil contained in the working medium;
An oil supply flow path for supplying oil recovered by the oil recovery machine to the expander,
The said heater is a thermal energy recovery apparatus connected to the said oil supply flow path so that the said shunt medium may be heated with the said oil. In the thermal energy recovery device according to any one of claims 2 to 6,
A heat exchanger provided in a portion between the pump and the heater in the diversion channel,
The heat exchanger is a medium for heating the diversion medium flow path through which the diversion medium flows and the diversion medium flow through the diversion medium flow path, and the heating medium after heat exchange with the working medium in the evaporator And a heating medium flow path through which heat flows. In the thermal energy recovery device according to any one of claims 2 to 6,
A heat exchanger provided in a portion between the pump and the heater in the diversion channel,
The heat exchanger is a medium for heating the diversion medium flow path through which the diversion medium flows and the diversion medium flow path through the diversion medium flow path, and flows into the condenser after flowing out of the expander. And a heating medium flow path through which the previous working medium flows. In the thermal energy recovery device according to any one of claims 1 to 8,
The expander has a first expansion part that expands the working medium, and a second expansion part that further expands the working medium after being expanded in the first expansion part,
The said shunt flow path is a thermal energy recovery apparatus connected between said 1st expansion part and said 2nd expansion part which are said middle stage parts.

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