JP2014211297A - Rankine cycle device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a Rankine cycle device capable of improving cycle efficiency while ensuring a long product life.SOLUTION: A Rankine cycle device of the present disclosure comprises: an expansion unit; a condenser; a pump; an evaporator 5a; and a heat medium flow path 9 in which the evaporator 5a is arranged so as to supply a heat medium to the evaporator 5a. The evaporator 5a includes an internal tube 51 and an external tube 53. The external tube 53 has an inner circumferential surface 53i in partial contact with an outer circumferential surface of the internal tube 51. One end 53a of the external tube 53 is closed, thereby forming a reservoir space in which gas can reside between the external tube 53 and the internal tube 51. An outer circumferential surface 53s of the external tube 53 includes an upstream-side heat inlet surface 53c located on the most upstream side in a heat medium flow direction in the heat medium flow path 9. The reservoir space communicates with a space outside of the reservoir space at a specific position P1 at an ambient temperature lower than that on the upstream-side heat inlet surface 53c.

Description

  The present invention relates to a Rankine cycle apparatus.

  Conventionally, a Rankine cycle apparatus is known as an apparatus for generating electricity. As a Rankine cycle apparatus, a Rankine cycle apparatus that evaporates the working fluid by exchanging heat between the oil heated by the exhaust gas of the boiler and the working fluid is known.

  As shown in FIG. 14, Patent Document 1 discloses a Rankine cycle apparatus 600 having an expander 601, an intermediate economizer 602, a condenser 603, a pump 604, and an evaporator 605. The evaporator 605 is formed by a duct having a coiled double tube structure. A working fluid flows inside the inner pipe 651 of the duct having the double pipe structure. In addition, oil exists in the space between the inner tube 651 and the outer tube 653 of the double tube structure duct. As the exhaust gas generated by the burner 623 passes through the evaporator 605, the oil is heated. The evaporator 605 evaporates the working fluid by exchanging heat between the heated oil and the working fluid.

European Patent Application No. 2014880 Specification

  The Rankine cycle apparatus 600 has a long product life because the oil heated by the exhaust gas generated by the burner 623 and the working fluid exchange heat. However, the Rankine cycle apparatus 600 has room for improving the efficiency of the Rankine cycle. Accordingly, an object of the present invention is to improve the efficiency of the Rankine cycle while ensuring a long product life of the Rankine cycle device.

This disclosure
An expander that extracts power by expanding the working fluid;
A condenser for condensing the working fluid expanded by the expander;
A pump for pressurizing the working fluid condensed in the condenser;
An evaporator that evaporates the heating fluid pressurized by the pump by heating with a heat medium;
A heat medium flow path in which the evaporator is arranged so that the heat medium is supplied to the evaporator, and
The evaporator has an inner tube forming a flow path for the working fluid and an outer tube provided outside the inner tube,
The outer tube has an outer peripheral surface to be heated by the heat medium, and an inner peripheral surface that is partially connected to or in contact with the outer peripheral surface of the inner tube,
A retention space in which gas can stay is formed between the inner peripheral surface of the outer tube and the outer peripheral surface of the inner tube by closing one end of the outer tube,
The outer peripheral surface of the outer pipe includes an upstream heat input surface located on the most upstream side in the flow direction of the heat medium in the heat medium flow path,
The stay space communicates with a space outside the stay space at a specific position where the ambient temperature is lower than the ambient temperature on the upstream heat input surface, or the stay depends on the pressure of the stay space. A ventilation mechanism for communicating the space with the external space is provided in the outer pipe at the specific position.
A Rankine cycle device is provided.

  According to the present disclosure, it is possible to improve Rankine cycle efficiency while securing a long product life of the Rankine cycle device.

Configuration of Rankine cycle device according to the first embodiment The block diagram of the evaporator which concerns on 1st Embodiment Sectional drawing which shows the internal structure of the evaporator which concerns on 1st Embodiment Sectional drawing which shows the internal structure of the evaporator which concerns on the modification 1. Sectional drawing which shows the internal structure of the evaporator which concerns on the modification 2. Sectional drawing which shows the internal structure of the evaporator which concerns on the modification 3. Sectional drawing which shows the internal structure of the evaporator which concerns on the modification 4. The block diagram of the evaporator concerning the modification 5 Sectional view along line IX-IX in FIG. The block diagram of the evaporator concerning another modification The block diagram of the Rankine-cycle apparatus which concerns on 2nd Embodiment The block diagram of the evaporator of the Rankine cycle apparatus concerning a 2nd embodiment Configuration diagram of Rankine cycle device according to the third embodiment Configuration diagram of conventional Rankine cycle equipment

  As the working fluid of the Rankine cycle apparatus, a fluid containing a hydrocarbon or fluorine (for example, a compound containing hydrogen atoms, carbon atoms, and fluorine atoms as constituent atoms) may be used. When the hydrocarbon comes into contact with a high-temperature heat medium, the hydrocarbon may be heated to the ignition point and burned. Further, when a fluid containing fluorine comes into contact with a high-temperature heat medium, hydrofluoric acid may be generated due to thermal decomposition. The combustion of hydrocarbons or the generation of hydrofluoric acid may reduce the product life by damaging the apparatus (for example, the portion constituting the flow path of the heat medium).

  Therefore, in order to ensure a long product life of the Rankine cycle apparatus, it is conceivable to configure an evaporator like the Rankine cycle apparatus 600 described above. In other words, a secondary heat medium such as hot water, steam, and oil is heated by a primary heat medium such as high-temperature combustion gas, furnace or internal combustion engine exhaust gas, and heat exchange between the secondary heat medium and the Rankine cycle working fluid. It is conceivable to configure the evaporator so that it does. Thereby, even if the working fluid leaks, the working fluid comes into contact with the secondary heat medium whose temperature is lower than the temperature of the primary heat medium, so that the working fluid does not easily burn or decompose. Further, by using a secondary heat medium having low reactivity and low combustibility in the atmosphere of the primary heat medium, combustion or thermal decomposition of the secondary heat medium can be prevented when the secondary heat medium leaks. According to such a configuration, a long product life of the Rankine cycle device can be ensured.

  However, according to said structure, since the temperature of a secondary heat medium is lower than the temperature of a primary heat medium, the heating amount of the working fluid in an evaporator is restrict | limited and it is difficult to improve the efficiency of a Rankine cycle. In order to increase the heating amount of the working fluid in the evaporator, it is necessary to enlarge the evaporator, which increases the manufacturing cost of the apparatus. Further, when a pump is provided to circulate the secondary heat medium, the power transmission end efficiency of the Rankine cycle device is reduced by the power required by the pump. Furthermore, the manufacturing cost of the apparatus increases due to piping construction for forming the flow path of the secondary heat medium, installation of a heat exchanger for heat exchange between the primary heat medium and the secondary heat medium, installation of a pump, and the like. .

The first aspect of the present disclosure is:
An expander that extracts power by expanding the working fluid;
A condenser for condensing the working fluid expanded by the expander;
A pump for pressurizing the working fluid condensed in the condenser;
An evaporator that evaporates the heating fluid pressurized by the pump by heating with a heat medium;
A heat medium flow path in which the evaporator is arranged so that the heat medium is supplied to the evaporator, and
The evaporator has an inner tube forming a flow path for the working fluid and an outer tube provided outside the inner tube,
The outer tube has an outer peripheral surface to be heated by the heat medium, and an inner peripheral surface that is partially connected to or in contact with the outer peripheral surface of the inner tube,
A retention space in which gas can stay is formed between the inner peripheral surface of the outer tube and the outer peripheral surface of the inner tube by closing one end of the outer tube,
The outer peripheral surface of the outer pipe includes an upstream heat input surface located on the most upstream side in the flow direction of the heat medium in the heat medium flow path,
The stay space communicates with a space outside the stay space at a specific position where the ambient temperature is lower than the ambient temperature on the upstream heat input surface, or the stay depends on the pressure of the stay space. A ventilation mechanism for communicating the space with the external space is provided in the outer pipe at the specific position.
A Rankine cycle device is provided.

  According to the first aspect, when the working fluid leaks due to damage to the inner tube, the leaked working fluid flows through the retention space and has an ambient temperature lower than the ambient temperature on the upstream heat input surface. Is discharged outside the staying space. Since the ambient temperature at the specific position is lower than the ambient temperature on the upstream heat input surface, the working fluid does not easily burn or decompose. Further, since the working fluid flowing in the staying space is cooled by the working fluid flowing in the inner pipe, it does not burn or pyrolyze. For this reason, the long product life of a Rankine cycle apparatus is securable. Further, since the outer tube has an inner peripheral surface that is partially connected to or in contact with the outer peripheral surface of the inner tube, heat transfer resistance between the outer peripheral surface of the outer tube and the inner peripheral surface of the inner tube. Becomes smaller. For this reason, since the heating amount of the working fluid in an evaporator can be increased, the efficiency of a Rankine cycle can be improved.

  In the second aspect of the present disclosure, in addition to the first aspect, the specific position is a position in the heat medium flow path, and is located downstream of the upstream heat input surface. A cycle device is provided. When the heat medium and the working fluid exchange heat on the upstream heat input surface, the temperature of the heat medium flowing through the heat medium flow path rapidly decreases. For this reason, the temperature of the heat medium is relatively lower on the downstream side than the upstream heat input surface. According to the second aspect, the leaked working fluid comes into contact with the heat medium on the downstream side of the upstream heat input surface of the heat medium, so that the working fluid does not easily burn or decompose. For this reason, the long product life of a Rankine cycle apparatus is securable.

  According to a third aspect of the present disclosure, in addition to the second aspect, the outer pipe has a portion farthest from the upstream heat input surface in the flow direction of the heat medium, and the farthest portion is the specific part. A Rankine cycle device in position is provided. According to the third aspect, since the temperature of the heat medium is low in the farthest part, even if the leaked working fluid comes into contact with the heat medium, the working fluid does not easily burn or decompose. For this reason, the long product life of a Rankine cycle apparatus is securable.

  According to a fourth aspect of the present disclosure, in addition to the first aspect, the specific position is a position outside the heat medium flow path. According to the 4th aspect, since the leaked working fluid is discharged | emitted by the low temperature atmosphere outside a heat-medium flow path, the long-term product life of a Rankine cycle apparatus can be ensured.

  5th aspect of this indication provides the Rankine cycle apparatus which has the other end of the said outer tube | pipe in the said specific position in addition to any one aspect of a 1st aspect-a 4th aspect. According to the fifth aspect, it is easy to process the outer tube for communicating the stay space with the space outside the stay space.

According to a sixth aspect of the present disclosure, in addition to any one of the first to fifth aspects, a Rankine cycle device is provided in which the outer tube is made of stainless steel. According to the sixth aspect, since the outer tube has corrosion resistance, it is possible to prevent the outer tube from corroding due to condensation of water vapor containing NO _x , SO _{x and the} like contained in the heat medium in the outer tube.

  According to a seventh aspect of the present disclosure, in addition to any one of the first to sixth aspects, a Rankine cycle device is provided in which the inner tube is made of copper or a copper alloy. According to the seventh aspect, the inner tube can be easily processed. Moreover, the heat transfer performance of the inner pipe is high.

The eighth aspect of the present disclosure includes, in addition to any one of the first aspect to the seventh aspect,
(I) The outer peripheral surface of the inner tube is formed such that a plurality of concave portions and a plurality of convex portions extending in the longitudinal direction of the inner tube are alternately arranged in the circumferential direction of the inner tube, and the plurality of convex portions Is in contact with the inner peripheral surface of the outer tube,
(Ii) The inner peripheral surface of the outer tube is formed such that a plurality of concave portions and a plurality of convex portions extending in the longitudinal direction of the outer tube are alternately arranged in the circumferential direction of the outer tube, and the plurality of convex portions A portion is in contact with the outer peripheral surface of the inner tube,
(Iii) The outer tube or the inner tube is formed in a polygonal tubular shape, and the inner peripheral surface of the outer tube is in contact with the outer peripheral surface of the inner tube at a plurality of positions separated from each other in the circumferential direction of the outer tube. Or (iv) the outer tube having a plurality of ribs that are separated from each other in the circumferential direction of the outer tube, extend in the longitudinal direction of the outer tube, and connect the outer tube and the inner tube to each other. Provided is a Rankine cycle device in which a plurality of staying spaces are formed by integrally molding the inner tube.

  According to the eighth aspect, the following effects can be obtained. In the case of (i) above, since the heat transfer resistance between the outer peripheral surface of the outer tube and the inner peripheral surface of the inner tube is small, it is only necessary to process the outer peripheral surface of the inner tube. It is easy to process the tube for this purpose. In the case of (ii) above, the heat transfer resistance between the outer peripheral surface of the outer tube and the inner peripheral surface of the inner tube is small. In the case of (iii), the heat transfer resistance between the outer peripheral surface of the outer tube and the inner peripheral surface of the inner tube is small. In the case of (iv) above, in addition to the small heat transfer resistance between the outer peripheral surface of the outer tube and the inner peripheral surface of the inner tube, there is no thermal resistance caused by contacting the outer tube and the inner tube. The heat transfer performance of the evaporator is high.

  The ninth aspect of the present disclosure further includes a pressure switch and a control device in addition to any one of the first aspect to the eighth aspect, and the pressure of the residence space is equal to or higher than a threshold pressure by the pressure switch. When it is detected that the temperature has risen, the control device provides a Rankine cycle device that executes a predetermined electrical process including a process for stopping the supply of the heat medium to the heat medium flow path. To do. According to the ninth aspect, when the working fluid leaks, the supply of the heat medium to the heat medium flow path can be stopped.

  According to a tenth aspect of the present disclosure, in addition to any one of the first to eighth aspects, a control device, a condensation temperature of the working fluid in the condenser, or the working fluid at the outlet of the condenser. A condensing temperature sensor for detecting the temperature; and a pump temperature sensor for detecting the temperature of the working fluid at the outlet of the pump, wherein the temperature of the working fluid detected by the pump temperature sensor is When the temperature of the working fluid detected by the condensation temperature sensor is greater than a threshold value, the control device includes a predetermined electrical process including a process for stopping the supply of the heat medium to the heat medium flow path. Provided is a Rankine cycle device for executing processing. If the working fluid leaks, it is difficult for the working fluid to be in a supercooled state in the condenser, so that the temperature of the working fluid detected by the pump temperature sensor is greater than the threshold temperature than the temperature of the working fluid detected by the condensing temperature sensor. . According to the tenth aspect, leakage of the working fluid can be detected by the condensation temperature sensor and the pump temperature sensor, and supply of the heat medium to the heat medium flow path can be stopped.

  In an eleventh aspect of the present disclosure, in addition to any one of the first to eighth aspects, a control device, an inlet temperature sensor for detecting the temperature of the working fluid at the inlet of the expander, And when the value detected by the inlet temperature sensor fluctuates periodically, the control device includes a predetermined electric power including processing for stopping the supply of the heat medium to the heat medium flow path. Provided is a Rankine cycle device that performs a general process. If the working fluid leaks, the working fluid at the inlet of the pump does not become a sufficient supercooled liquid state, and the working fluid in the gas phase intermittently flows into the pump and the pump flow rate fluctuates. The temperature of the working fluid in fluctuates periodically. According to the eleventh aspect, when the periodic fluctuation of the temperature of the working fluid is detected, the supply of the heat medium to the heat medium flow path can be stopped.

  In a twelfth aspect of the present disclosure, in addition to any one of the ninth to eleventh aspects, the predetermined electrical processing is performed until the supply of the heat medium to the heat medium flow path is stopped. A Rankine cycle device including a process for operating the device is provided. According to the twelfth aspect, at least until the supply of the heat medium to the heat medium flow path is stopped, the leaked working fluid flowing through the staying space can be cooled by flowing the working fluid through the inner pipe. it can.

  According to a thirteenth aspect of the present disclosure, in addition to any one of the ninth to eleventh aspects, an inlet on-off valve provided in a flow path of the working fluid at an inlet of the evaporator, and the evaporator An outlet on-off valve provided in the flow path of the working fluid at the outlet, an inlet temperature sensor for detecting the temperature of the working fluid at the inlet of the expander, and a generator connected to the expander. The control device may further comprise the electric motor in a state where the pump is stopped and the inlet on / off valve is closed in place of the predetermined electrical process or together with the predetermined electrical process. A recovery operation in which the working fluid in the evaporator is forcibly sent to the condenser by being driven as a temperature of the working fluid detected by the inlet temperature sensor during the execution of the recovery operation. But Wherein by closing the outlet shutoff valve to perform electrical processing for recovery including a process for stopping the driving of the motor of the generator if it exceeds a value temperature, to provide a Rankine cycle system. According to the thirteenth aspect, the leakage of the working fluid can be stopped early.

  The fourteenth aspect of the present disclosure further includes an alarm device in addition to any one of the ninth to eleventh aspects, and the predetermined electrical process controls the alarm device to issue an alarm. A Rankine cycle device is provided, including a process for. According to the fourteenth aspect, the user can easily notice the leakage of the working fluid, and measures necessary for maintenance to maintain the product life can be taken early.

  According to a fifteenth aspect of the present disclosure, in addition to any one of the first aspect to the fourteenth aspect, when the Rankine cycle device is activated, the heat medium flow path is generated before the heat medium is generated. Provided is a Rankine cycle device that operates a fan that supplies outside air. According to the fifteenth aspect, when the working fluid leaks while the Rankine cycle device is stopped and the working fluid exists in the heat medium flow path, the heat medium is supplied before the heat medium is supplied to the heat medium flow path. The working fluid existing in the flow path can be discharged from the heat medium flow path.

  In a sixteenth aspect of the present disclosure, in addition to any one of the first to fifteenth aspects, when the Rankine cycle device is activated, the pump is operated before the heat medium is generated. A Rankine cycle device is provided. According to the sixteenth aspect, when the working fluid is leaking while the Rankine cycle device is stopped, the working fluid leaked immediately after the heat medium is supplied to the heat medium flow path flows through the inner pipe. Can be cooled by working fluid.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following description relates to an example of the present invention, and the present invention is not limited to these.

<First Embodiment>
As shown in FIG. 1, the Rankine cycle apparatus 100 includes an expander 1, a reheater 2, a condenser 3, a pump 4, and an evaporator 5a. Since these are connected by piping, the flow path of the working fluid of Rankine cycle apparatus 100 is constituted. The Rankine cycle apparatus 100 includes a main circuit 11 and a bypass circuit 12 as a flow path for the working fluid. The main circuit 11 connects the expander 1, the reheater 2 (low pressure side), the condenser 3, the pump 4, the reheater 2 (high pressure side), and the evaporator 5 a in this order using a pipe in a ring shape. Is made up of. The bypass circuit 12 branches from the main circuit 11 between the evaporator 5a and the expander 1, and joins the main circuit 11 between the expander 1 and the reheater 2 (low pressure side). An expansion valve 7 is provided in the bypass circuit 12. The expansion valve 7 is an electric expansion valve, for example. The main circuit 11 is provided with an on-off valve 6 near the inlet of the expander 1 rather than the branch position between the main circuit 11 and the bypass circuit 12. The on-off valve 6 is, for example, an electromagnetic on-off valve.

  The expander 1 takes out power by expanding a working fluid. Electricity is generated by driving a generator (not shown) connected to the expander 1 by the extracted power. The condenser 3 condenses the working fluid expanded by the expander 1. The pump 4 pressurizes the working fluid condensed by the condenser 3 and supplies it to the evaporator 5a. The working fluid circulates through the main circuit 11 or the bypass circuit 12 by the action of the pump 4. The evaporator 5a evaporates by heating the working fluid pressurized by the pump 4 with a heat medium. The Rankine cycle apparatus 100 has a heat medium flow path 9 in which the evaporator 5a is arranged so that the heat medium is supplied to the evaporator 5a.

  The reheater 2 includes a low-pressure side heat exchange unit 2a and a high-pressure side heat exchange unit 2b. The low-pressure side heat exchange unit 2 a is provided at a position between the expander 1 and the condenser 3 in the main circuit 11. Further, the low-pressure side heat exchanging portion 2 a is provided on the downstream side of the joining position of the main circuit 11 and the bypass circuit 12. The high-pressure side heat exchange unit 2b is provided at a position between the pump 4 and the evaporator 5a of the main circuit 11. In the reheater 2, the working fluid flowing through the high-pressure side heat exchange unit 2b is heated by the working fluid flowing through the low-pressure side heat exchange unit 2a. Thereby, the working fluid supplied to the evaporator 5a can be preheated.

  The condenser 3 has a cooled part 3a and a cooling part 3b. The working fluid flows through the cooled part 3a. In addition, a cooling heat medium for cooling the working fluid flows through the cooling unit 3b. The cooling heat medium is, for example, water. In the present embodiment, the hot water circuit 34 is configured by connecting the cooling unit 3b, the radiator 31 or the hot water heater 33, and the pump 35 in an annular shape by piping. The hot water heater 33 is disposed inside the hot water tank 32. In the present embodiment, the radiator 31 and the hot water heater 33 are provided in parallel in the hot water circuit 34. The radiator 31 and the hot water heater 33 may be provided in series in the hot water circuit 34. The cooling heat medium flowing through the cooling unit 3b is heated by exchanging heat with the working fluid flowing through the cooled unit 3a. On the other hand, the working fluid flowing through the cooled portion 3a is cooled and condensed by the cooling heat medium flowing through the cooling portion 3b. The heat of the heated cooling heat medium is dissipated in the radiator 31 or the hot water heater 33, so that the temperature of the cooling heat medium decreases. The cooling heat medium having the lowered temperature is sent again to the cooling unit 3b by the pump 35.

  A heat medium is supplied to the heat medium flow path 9 from a predetermined heat source. In the present embodiment, the heat medium flow path 9 is formed inside the boiler 21 having the combustor 23a. The boiler 21 has a fan 17 for supplying air to the combustor 23a. The fan 17 is provided so that the combustor 23 a is located between the fan 17 and the heat medium flow path 9. As the fuel burns in the combustor 23a, combustion gas as a heat medium is generated. This combustion gas is supplied to the evaporator 5 a through the heat medium flow path 9. The combustion gas flows around the evaporator 5 a and then is discharged from the exhaust duct of the boiler 21 to the outside of the boiler 21.

  The Rankine cycle device 100 further includes a control device 10a, a condensation temperature sensor 8a, and a pump temperature sensor 8b. The condensation temperature sensor 8 a is a sensor for detecting the condensation temperature of the working fluid in the condenser 3 or the temperature of the working fluid at the outlet of the condenser 3. The pump temperature sensor 8 b is a sensor for detecting the temperature of the working fluid at the outlet of the pump 4. The control device 10a performs various electrical processes to cause the Rankine cycle device 100 and the boiler 21 to perform predetermined operations.

  As shown in FIG. 2, the evaporator 5 a has an inner tube 51 and an outer tube 53. The outer tube 53 is provided outside the inner tube 51. That is, the evaporator 5 a has a double tube structure of the inner tube 51 and the outer tube 53. As shown in FIG. 3, the inner pipe 51 forms a flow path 55 for the working fluid. The evaporator 5a is connected to the outer pipe from one end 53a of the outer pipe 53 so as to intersect the flow direction of the heat medium in the heat medium flow path 9 at a plurality of positions separated from each other in the flow direction of the heat medium in the heat medium flow path 9. 53 extends toward the other end 53b. That is, the evaporator 5 a extends while meandering from the upstream side of the heat medium flow path 9 toward the downstream side of the heat medium flow path 9. The evaporator 5a is, for example, a fin tube heat exchanger.

  The outer tube 53 has an outer peripheral surface 53s to be heated by the heat medium and an inner peripheral surface 53i. The inner peripheral surface 53 i of the outer tube 53 is in partial contact with the outer peripheral surface 51 s of the inner tube 51. Further, one end 53a of the outer tube 53 is closed. As a result, a stay space 57 in which gas can stay is formed between the inner peripheral surface 53 i of the outer tube 53 and the outer peripheral surface 51 s of the inner tube 51. As shown in FIG. 2, the outer peripheral surface 53 s of the outer tube 53 includes an upstream heat input surface 53 c that is located on the most upstream side in the heat medium flow direction in the heat medium flow path 9. The stay space 57 communicates with a space outside the stay space 57 at a specific position P1 at which the ambient temperature is lower than the ambient temperature on the upstream heat input surface 53c. In other words, the outer tube 53 has an opening H at the specific position P1. In the present embodiment, the specific position P1 is a position in the heat medium flow path 9 and is located downstream of the upstream heat input surface 53c. For this reason, the outer tube 53 has an opening H on the downstream side of the upstream heat input surface 53 c of the heat medium flow path 9.

  In the present embodiment, the outer tube 53 has a portion farthest from the upstream heat input surface 53 c in the heat medium flow direction in the heat medium flow path 9. In the present embodiment, this most distant portion is at the specific position P1. For this reason, the outer tube 53 has an opening H at the most distant portion. Furthermore, in the present embodiment, the other end 53b of the outer tube 53 is at the specific position P1. For this reason, the outer tube 53 has an opening H at the other end 53b.

  A plurality of staying spaces 57 are formed between the inner peripheral surface 53 i of the outer tube 53 and the outer peripheral surface 51 s of the inner tube 51. Specifically, as shown in FIG. 3, the outer peripheral surface 51 s of the inner tube 51 has a plurality of concave portions 51 r and a plurality of convex portions 51 p extending in the longitudinal direction of the inner tube 51 alternately arranged in the circumferential direction of the inner tube 51. Is formed. A plurality of staying spaces 57 are formed by the plurality of convex portions 51 p being in contact with the inner peripheral surface 53 i of the outer tube 53.

Heat medium may contain NO _X or SO _X. When water vapor that has taken in NO _x or SO _x is condensed on the outer pipe 53, the outer pipe 53 may be corroded. For this reason, it is desirable that the outer tube 53 be made of a material having corrosion resistance. In the present embodiment, the outer tube 53 is made of stainless steel, for example.

  Since the heat of the heat medium is transferred to the working fluid via the inner pipe 51, the inner pipe 51 is preferably made of a material having good heat transfer characteristics. In the present embodiment, the inner tube 51 is made of, for example, copper or a copper alloy. Further, when the inner tube 51 is made of copper or a copper alloy, the inner tube 51 can be easily processed.

  The working fluid used in the Rankine cycle apparatus 100 is not particularly limited, but for example, an organic working fluid can be suitably used. Organic working fluids include halogenated hydrocarbons, hydrocarbons, alcohols and the like. Examples of the halogenated hydrocarbon include R-123 and R-245fa. Examples of the hydrocarbon include alkanes such as propane, butane, pentane, and isopentane. Examples of alcohol include ethanol. These organic working fluids may be used alone or in combination of two or more.

  Next, the operation of the Rankine cycle apparatus 100 will be described. First, the pump 35 is started to exchange heat between the working fluid in the cooled portion 3a and the cooling heat medium in the cooling portion 3b. In this way, cooling of the working fluid is started. Further, before the heat medium is generated, the fan 17 is operated to supply outside air to the heat medium flow path 9. Next, with the on-off valve 6 closed and the opening degree of the expansion valve 7 set large, the pump 4 is operated to circulate the working fluid. The pump 4 is operated before the heat medium is generated.

  After the operation of the pump 4 is started, fuel is supplied to the combustor 23a of the boiler 21 and is reacted with air supplied by the fan 17 to burn the fuel. Thereby, the heat medium which is a combustion gas of fuel is generated. The heat medium flows through the heat medium flow path 9 and is supplied to the evaporator 5a. The heat medium supplied to the evaporator 5a exchanges heat with the working fluid flowing through the evaporator 5a to evaporate the liquid-phase working fluid. The working fluid flows from one end 53 a of the outer tube 53 toward the other end 53 b of the outer tube 53. A temperature gradient is generated between the outer peripheral surface 53 s of the outer tube 53 and the inner peripheral surface 51 i of the inner tube 51 by the heat medium passing through the outer peripheral surface 53 s of the outer tube 53 and the working fluid passing through the inside of the inner tube 51. As a result, the heat of the high-temperature heat medium moves toward the low-temperature working fluid. Since the inner peripheral surface 53 i of the outer tube 53 is in partial contact with the outer peripheral surface 51 s of the inner tube 51, the convex portion 51 p of the inner tube 51 having a smaller thermal resistance than the gas staying in the staying space 57 is formed. The heat of the heat medium is transmitted to the working fluid. At this time, the heat transfer coefficient in heat transfer between the working fluid flowing inside the inner tube 51 and the inner peripheral surface 51 i of the inner tube 51 is the heat medium flowing outside the outer tube 53 and the outer peripheral surface 53 s of the outer tube 53. It is considerably higher than the heat transfer coefficient in heat transfer between. Further, the thermal conductivity from the outer peripheral surface 53s of the outer tube 53 to the inner peripheral surface 51i of the inner tube 51 is very high. For this reason, the temperature gradient from the outer peripheral surface 53s of the outer tube 53 to the inner peripheral surface 51i of the inner tube 51 is relatively small, and most of the temperatures of the inner tube 51 and the outer tube 53 are close to the temperature of the working fluid. Therefore, the stay space 57 is kept at a low temperature close to the temperature of the working fluid flowing in the inner pipe 51.

  First, the heat medium exchanges heat with the working fluid at the upstream heat input surface 53c. A lot of heat is taken away from the heat medium on the upstream heat input surface 53c. For this reason, the temperature of the heat medium flowing downstream from the upstream heat input surface 53c of the heat medium flow path 9 is compared with the temperature of the heat medium flowing upstream from the upstream heat input surface 53c. It has greatly decreased. Even after the heat medium passes through the upstream heat input surface 53c, the heat medium continues to be deprived of heat by being in contact with the evaporator 5a, so that the temperature of the heat medium decreases toward the downstream of the heat medium flow path 9. After passing through the evaporator 5a, the heat medium is discharged to the outside from the exhaust duct at the top of the boiler 21.

  In the evaporator 5a, the working fluid is evaporated to become superheated steam. The working fluid that is superheated steam flows through the bypass circuit 12 and reaches the condenser 3. In the condenser 3, the working fluid that is superheated steam is condensed by being cooled by the cooling heat medium of the hot water circuit 34, and becomes a liquid phase state. The working fluid in the liquid phase returns to the pump 4. In this way, the working fluid circulates through the main circuit 11 or the bypass circuit 12. In the reheater 2, the high temperature working fluid flowing through the low pressure side heat exchanging portion 2a and the low temperature working fluid flowing through the high pressure side heat exchanging portion 2b exchange heat, and flow through the low pressure side heat exchanging portion 2a. The working fluid that is flowing is cooled, and the working fluid that is flowing through the high-pressure side heat exchanger 2b is heated.

  Next, when the working fluid shows a sufficient degree of superheat at the outlet of the evaporator 5a, the opening of the expansion valve 7 is reduced and the on-off valve 6 is opened. As a result, superheated steam is supplied to the expander 1, pressure energy of the working fluid is converted into rotational power by the expander 1, and power is extracted. Electric power can be obtained by driving a generator (not shown) with the extracted power. This power can also be used as mechanical power.

  In the condenser 3, the cooling heat medium is heated by the working fluid. By supplying the cooling heat medium heated in the condenser 3 to the radiator 31 or the hot water heater 33, heating or hot water heating can be performed.

  Next, the operation of the Rankine cycle apparatus 100 when the inner pipe 51 is damaged and the working fluid flowing through the inner pipe 51 leaks will be described. When the working fluid leaks from the inner pipe 51, the working fluid flows out to the staying space 57. The working fluid that has flowed out into the staying space 57 flows toward a specific position P1 where the staying space 57 communicates with a space outside the staying space 57. The working fluid that has reached the specific position P <b> 1 flows out to a space outside the staying space 57. Here, since the atmospheric temperature at the specific position P1 is lower than the atmospheric temperature at the upstream heat input surface 53c, even if the working fluid flows out to the space outside the staying space 57 at the specific position P1, the operation is performed. The fluid is difficult to burn or pyrolyze. The temperature of the combustion gas produced | generated by the combustor 23a is 700-1500 degreeC, for example. When reaching the most downstream line of the evaporator 5a in the heat medium flow path 9, the temperature of the combustion gas decreases to, for example, 50 to 250 ° C. The working fluid that has flowed out to the space outside the staying space 57 is discharged from the exhaust duct of the boiler 21 together with the flow of the heat medium. For this reason, the long product life of Rankine cycle apparatus 100 is securable.

  When the working fluid leaks into the retention space 57, the amount of the working fluid flowing through the main circuit 11 of the Rankine cycle device 100 is reduced, so that the amount of the liquid-phase working fluid held on the outlet side of the condenser 3 is reduced. To do. Therefore, the degree of supercooling of the working fluid supplied from the condenser 3 to the pump 4 is reduced, and the working fluid in a gas-liquid two-phase state is supplied to the pump 4. In this case, the pressure of the gas-phase working fluid is increased by the pump 4, so that the temperature of the working fluid rises. As a result, there is a relatively large difference between the temperature of the working fluid detected by the condensation temperature sensor 8a and the temperature of the working fluid detected by the pump temperature sensor 8b. In other words, there is a possibility that the working fluid is leaked when the temperature T1 of the working fluid detected by the pump temperature sensor 8b is larger than the threshold value by the threshold value T2 of the working fluid detected by the condensation temperature sensor 8a. . For example, when the temperature difference (T1−T2) obtained by subtracting the temperature T2 from the temperature T1 becomes 10 ° C. or more, the working fluid may be leaking.

  The measurement value of the condensation temperature sensor 8a and the measurement value of the pump temperature sensor 8b are input to the control device 10a. When the temperature of the working fluid detected by the pump temperature sensor 8b is larger than the temperature of the working fluid detected by the condensation temperature sensor 8a by a threshold or more, the control device 10a supplies the heat medium to the heat medium flow path 9. A predetermined electrical process including a process for stopping the process is executed. Specifically, the control device 10a executes a process for stopping the supply of fuel to the combustor 23a. Such processing includes stopping a fuel pump (not shown), closing a valve provided in a fuel supply line (not shown), and the like. Thereby, since supply of the heat medium to the heat medium flow path 9 is stopped when the working fluid leaks, the ambient temperature around the evaporator 5a rapidly decreases. In this case, if the operation of the fan 17 is continued, low-temperature air can be supplied to the heat medium flow path 9, so that the ambient temperature around the evaporator 5a can be further lowered. Thereby, since combustion or thermal decomposition of the leaked working fluid is suppressed, a long product life of the Rankine cycle apparatus 100 is ensured.

  The pump 4 is operated until the temperature of the working fluid in the evaporator 5a is sufficiently lowered. Specifically, the predetermined electrical process includes a process for operating the pump 4 until the supply of the heat medium to the heat medium flow path 9 is stopped. For this reason, at least until the supply of the heat medium to the heat medium flow path 9 is stopped, the leaked working fluid flowing through the stay space 57 can be cooled by flowing the working fluid through the inner pipe 51.

  As shown in FIG. 1, the Rankine cycle device 100 includes an alarm device 40. The predetermined electrical process to be executed by the control device 10a may include a process for controlling the alarm device 40 to issue an alarm. Thereby, when the working fluid is leaking, the alarm device 40 issues an alarm. The alarm device 40 is, for example, a speaker that emits an alarm sound or an alarm lamp that emits an alarm when turned on. Further, the alarm device 40 may be configured to notify the alarm information to a predetermined communication destination by wired or wireless communication. In addition, the alarm device 40 may be any device that emits an alarm perceptible to a person. The predetermined electrical process to be executed by the control device 10a may include a process for continuing the operation of the fan 17. For example, the supply of the heat medium to the heat medium flow path 9 is stopped until the leakage of the working fluid is stopped by the recovery operation, and the fan 17 is continuously operated.

  There is a possibility that the working fluid leaks while the Rankine cycle device 100 is stopped, and the working fluid exists in the heat medium flow path 9. As described above, when the Rankine cycle apparatus 100 is activated, the fan 17 is operated before the heat medium is generated. The fan 17 is provided so that the combustor 23 a is located between the fan 17 and the heat medium flow path 9. For this reason, the leaked working fluid existing in the heat medium flow path 9 together with the outside air supplied to the heat medium flow path 9 by the fan 17 flows downstream of the heat medium flow path 9. Further, the leaked working fluid is discharged to the outside of the boiler 21 from the exhaust duct of the boiler 21 located on the downstream side of the heat medium flow path 9. Thereby, the working fluid leaked before the heat medium is supplied to the heat medium flow path 9 can be discharged from the heat medium flow path 9.

  The first embodiment can be modified from various viewpoints. Below, some modifications of this embodiment are explained. The same reference numerals are given to the configurations of the modifications that are the same as or correspond to the configurations of the first embodiment, and detailed description thereof will be omitted.

(Modification 1)
FIG. 4 shows an evaporator 5b according to the first modification. The evaporator 5b differs from the evaporator 5a of the first embodiment in that a plurality of concave portions 53r and a plurality of convex portions 53p are formed on the inner peripheral surface 53i of the outer tube 53. Specifically, the inner peripheral surface 53 i of the outer tube 53 is formed so that a plurality of concave portions 53 r and a plurality of convex portions 53 p extending in the longitudinal direction of the outer tube 53 are alternately arranged in the circumferential direction of the outer tube 53. Further, a plurality of staying spaces 57 are formed by the plurality of convex portions 53p being in contact with the outer peripheral surface 51s of the inner tube 51.

(Modification 2 and Modification 3)
As shown in FIG. 5, in the evaporator 5c which concerns on the modification 2, the outer tube | pipe 53 is formed in the triangular tube shape, and the inner tube | pipe 51 is a circular tube. The inner peripheral surface 53 i of the outer tube 53 is in contact with the outer peripheral surface 51 s of the inner tube 51 at a plurality (three) positions separated from each other in the circumferential direction of the outer tube 53. As shown in FIG. 6, in the evaporator 5d which concerns on the modification 3, the outer tube | pipe 53 is formed in the hexagonal tubular shape. Further, the inner peripheral surface 53 i of the outer tube 53 is in contact with the outer peripheral surface 51 s of the inner tube 51 at a plurality (six) positions separated from each other in the circumferential direction of the outer tube 53. In this way, a plurality of staying spaces 57 are formed. If a plurality of staying spaces 57 are formed by contacting the inner peripheral surface 53i of the outer tube 53 and the outer peripheral surface 51s of the inner tube 51 at a plurality of positions separated from each other in the circumferential direction of the outer tube 53, The tube 53 may be formed in a polygonal tube other than a triangular tube or a hexagonal tube. The inner tube 51 may be formed in a polygonal tubular shape. That is, the outer tube 53 or the inner tube 51 is formed in a polygonal tubular shape, and the inner peripheral surface 53 i of the outer tube 53 is in contact with the outer peripheral surface 51 s of the inner tube 51 at a plurality of positions separated from each other in the circumferential direction of the outer tube 53. Thus, a plurality of staying spaces 57 may be formed. However, considering that the inner pipe 51 forms the working fluid flow path 55, the inner pipe 51 is preferably a circular pipe.

(Modification 4)
As shown in FIG. 7, in the evaporator 5e according to the modified example 4, the outer tube 53 and the inner tube 51 are integrally formed. That is, the outer tube 53 has an inner peripheral surface 53 i that is partially connected to the outer peripheral surface 51 s of the inner tube 51. Specifically, the outer tube 53 and the inner tube 53 have a plurality of ribs 50r that are separated from each other in the circumferential direction of the outer tube 53, extend in the longitudinal direction of the outer tube 53, and connect the outer tube 53 and the inner tube 51 to each other. The tube 51 is integrally formed. Thereby, a plurality of staying spaces 57 are formed. According to the modification 4, since the heat resistance by making the outer tube | pipe 53 and the inner tube | pipe 51 contact is not produced, the heat-transfer characteristic of the evaporator 5e is high. The evaporation pipe 5e according to the modification 4 can be produced by, for example, extrusion molding or pultrusion molding.

(Modification 5)
As shown in FIG. 8, the evaporator 5f according to the modified example 5 is formed in a coil shape wound so as to surround the combustor 23b. As shown in FIG. 9, the combustor 23b includes a cylindrical structure in which a large number of through holes 23h are formed along the circumferential direction and the axial direction. When the fuel is combusted inside the cylindrical structure, combustion gas as a heat medium is blown out in the radial direction of the combustor 23b through the through hole 23h. Thereby, the heat medium is supplied to the evaporator 5f. The boiler having the combustor 23b having such a structure is mainly spread in Europe, and is provided, for example, by VIESSMANN in Germany.

  The evaporator 5f surrounds the combustor 23b at a position slightly away from the combustor 23b. The evaporator 5f has a spiral structure with a predetermined pitch so as to form a gap 50s for allowing the heat medium to pass in the radial direction of the combustor 23b. The heat medium flow path 9 is formed by the space and the gap 50s between the evaporator 5f and the combustor 23b. The outer tube 53 and the inner tube 51 are formed in a square tube shape. The inner tube 51 has a convex portion on the outer peripheral surface 51 s, and the stay space 57 is formed by the convex portion being in contact with the inner peripheral surface 53 i of the outer tube 53. Since the heat medium flows through the heat medium flow path 9 in the radial direction of the combustor 23 b, the surface facing the combustor 23 b of the outer peripheral surface 53 s of the outer tube 53 is the most in the heat medium flow direction in the heat medium flow path 9. Located upstream. That is, the surface facing the combustor 23b in the outer peripheral surface of the outer tube 53 is the upstream heat input surface 53c.

  First, the heat medium 5 exchanges heat with the working fluid on the upstream heat input surface 53c. At the upstream heat input surface 53c, much heat is taken away from the heat medium. For this reason, the temperature of the heat medium flowing downstream from the upstream heat input surface 53c of the heat medium flow path 9 is compared with the temperature of the heat medium flowing upstream from the upstream heat input surface 53c. It has greatly decreased. That is, the ambient temperature at the radially outer side of the combustor 23 b is lower than the ambient temperature at the upstream heat input surface 53 than the upstream heat input surface 53 c. That is, an arbitrary position outside the combustor 23b in the radial direction from the upstream heat input surface 53c corresponds to the specific position P1. In the present modification, an opening H is formed on the outer surface 53s of the outer tube 53 on the surface opposite to the heat input side heat input surface 53c. Accordingly, the stay space 57 communicates with the space outside the stay space 57 at the specific position P1.

(Other variations)
As shown in FIG. 10, the specific position P <b> 1 may be a position outside the heat medium flow path 9. That is, the outer tube 53 may have an opening H at a position outside the heat medium flow path 9. In this case, the outer tube 53 extends through the wall of the boiler 21 to a space outside the boiler 21.

  The heat medium supplied to the evaporator 5a may be exhaust gas from a furnace or an internal combustion engine. Moreover, the gas warmed by geothermal or solar heat may be sufficient. If necessary, the bypass circuit 12, the reheater 2, and the like may be omitted.

Second Embodiment
Next, the Rankine cycle apparatus 200 according to the second embodiment of the present invention will be described. Note that the second embodiment is configured in the same manner as the first embodiment unless otherwise described. Components in the second embodiment that are the same as or correspond to components in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and may not be described in detail. That is, the description regarding the first embodiment and the modified example of the first embodiment is applied to the present embodiment as long as there is no technical contradiction.

  As shown in FIG. 11, the Rankine cycle apparatus 200 includes an inlet temperature sensor 8c instead of the condensation temperature sensor 8a and the pump temperature sensor 8b. The inlet temperature sensor 8 c is a sensor for detecting the temperature of the working fluid at the inlet of the expander 1. The measured value of the inlet temperature sensor 8c is input to the control device 10b. When the working fluid leaks in the evaporator 5, the degree of supercooling of the working fluid at the inlet of the pump 4 decreases, and the working fluid at the inlet of the pump 4 enters a gas-liquid two-phase state. In this case, since the liquid feeding amount of the pump 4 varies, the measured value of the inlet temperature sensor 8c varies periodically. For this reason, when the measured value of the inlet temperature sensor 8c fluctuates periodically, the working fluid may be leaking.

  When the value detected by the inlet temperature sensor 8c varies periodically, the control device 10b executes a predetermined electrical process. This predetermined electrical process includes a process for stopping the supply of the heat medium to the heat medium flow path 9 as in the first embodiment. This predetermined electrical process includes a process for operating the pump 4 until the supply of the heat medium to the heat medium flow path 9 is stopped or a process for controlling the alarm device 40 so as to issue an alarm. Also good.

  As shown in FIG. 12, the evaporator 5 g of the Rankine cycle apparatus 200 has a ventilation mechanism 58. The ventilation mechanism 58 is provided in the outer tube 53 at the specific position P1. The ventilation mechanism 58 makes the stay space 57 communicate with the outside space according to the pressure of the stay space 57. That is, the evaporator 5g is different from the evaporator 5a of the first embodiment in that a ventilation mechanism is provided at the specific position P1 instead of the opening H being formed at the specific position P1.

  The ventilation mechanism 58 is, for example, a relief valve 58 that allows the stay space 57 to communicate with the outside of the stay space. The relief valve 58 is provided at the other end 53b of the outer tube 53 at the specific position P1. When the relief valve 58 is closed, the stay space 57 is not in communication with the space outside the stay space 57. In this case, the stay space 57 is a sealed space. When the working fluid leaks from the inside of the inner pipe 51, the working fluid flows out into the staying space 57, so that the pressure in the staying space 57 increases. When the pressure in the stay space 57 rises above the threshold pressure, the relief valve 58 is opened. When the relief valve 58 is opened, the stay space 57 communicates with a space outside the stay space 57. As a result, the leaked working fluid is discharged to the space outside the staying space 57. When a predetermined amount of working fluid is discharged from the staying space 57 and the pressure in the staying space 57 falls below the threshold pressure, the relief valve 58 is closed again.

  The Rankine cycle device 200 includes a pressure switch 59 and a control device 10b. The pressure switch 59 is in an off state when the pressure in the stay space 57 is less than the threshold pressure. The pressure switch 59 is turned on when the pressure in the stay space 57 rises above the threshold pressure. Information regarding the on / off state of the pressure switch 59 is input to the control device 10b. The Rankine cycle device 200 may be configured such that the on / off state of the circuit can be switched similarly to the pressure switch 59 by combining a pressure sensor and a control device instead of the pressure switch 59. .

  When it is detected by the pressure switch 59 that the pressure in the stay space 57 has risen above the threshold pressure, the control device 10b performs a predetermined electrical process. The predetermined electrical process includes a process for stopping the supply of the heat medium to the heat medium flow path 9 as in the first embodiment. The predetermined electrical process may include a process for operating the pump 4 until the supply of the heat medium to the heat medium flow path 9 is stopped or a process for controlling the alarm device 40 to issue an alarm. Good.

<Third Embodiment>
Next, the Rankine cycle apparatus 300 according to the third embodiment of the present disclosure will be described. Note that the third embodiment is configured in the same manner as the second embodiment unless otherwise described. Components of the third embodiment that are the same as or correspond to components of the third embodiment and the second embodiment may be denoted by the same reference numerals as those of the second embodiment, and detailed description thereof may be omitted. That is, the description regarding the second embodiment is also applied to the present embodiment as long as there is no technical contradiction.

  As shown in FIG. 13, the Rankine cycle apparatus 300 includes an inlet on-off valve 13, an outlet on-off valve 14, an inlet temperature sensor 8c, and a generator 15. The inlet on-off valve 13 is, for example, an electromagnetic valve. It is provided in the flow path of the working fluid at the inlet of the evaporator 5g. The outlet opening / closing valve 14 is, for example, an electromagnetic valve, and is provided in the flow path of the working fluid at the outlet of the evaporator 5g. The inlet temperature sensor 8 c is a temperature sensor for detecting the temperature of the working fluid at the inlet of the expander 1. The measured value of the inlet temperature sensor 8c is input to the control device 10c. The generator 15 is connected to the expander 1. When the value detected by the inlet temperature sensor 8c periodically varies, the control device 10c replaces the predetermined electrical processing executed by the control device 10b or together with the predetermined electrical processing with the evaporator 5g. An electrical process is performed to recover the working fluid from An electrical process for recovering the working fluid from the evaporator 5g is referred to as an electrical process for recovery.

  When the control device 10c executes the electrical process for recovery, the recovery operation is executed in the Rankine cycle device 300. This recovery operation is an operation in which the working fluid of the evaporator 5g is forcibly sent to the condenser 3 by driving the generator 15 as an electric motor with the pump 4 stopped and the inlet opening / closing valve 14 closed. is there. Furthermore, when the temperature of the working fluid detected by the inlet temperature sensor 8c during the recovery operation exceeds the threshold temperature, the outlet on-off valve 14 is closed to stop the drive of the generator as an electric motor. That is, the electrical process for recovery to be executed by the control device 10c includes a process for closing the outlet opening / closing valve 14 and stopping the drive of the generator 15 as an electric motor. Such processing is executed when the temperature of the working fluid detected by the inlet temperature sensor 8c during execution of the recovery operation exceeds the threshold temperature. Thereby, the leakage of the working fluid can be stopped. In particular, even when the supply of the heat medium to the heat medium flow path 9 cannot be stopped, the leakage of the working fluid can be stopped.

  Information related to the on / off state of the pressure switch 59 may be input to the control device 10c as in the control device 10b of the second embodiment. When it is detected by the pressure switch 59 that the pressure in the staying space 57 has risen above the threshold pressure, the control device 10c replaces the predetermined electrical process or together with the predetermined electrical process for recovery. Electrical processing may be performed.

  As in the control device 10a of the first embodiment, the measurement value of the condensation temperature sensor 8a and the measurement value of the pump temperature sensor 8b may be input to the control device 10c. When the temperature of the working fluid detected by the pump temperature sensor 8b is higher than the threshold value by the threshold value than the temperature of the working fluid detected by the condensation temperature sensor 8a, the control device 10c replaces the predetermined electrical processing, or You may perform the electrical process for collection | recovery with a predetermined | prescribed electrical process.

DESCRIPTION OF SYMBOLS 1 Expander 3 Condenser 4 Pump 5a-5g Evaporator 8a Condensation temperature sensor 8b Pump temperature sensor 8c Inlet temperature sensor 9 Heat medium flow path 10a-10c Control device 13 Inlet opening / closing valve 14 Outlet opening / closing valve 15 Generator 17 Fan 40 Alarm Device 50r Rib 51 Inner tube 51i Inner tube inner surface 51s Inner tube outer surface 51p Convex portion 51r Recess 53 Outer tube 53a Outer tube one end 53b Outer tube other end 53c Upstream heat input surface 53i Outer tube inner tube Surface 53s Outer pipe outer peripheral surface 53p Convex part 53r Concave part 55 Fluid flow path 57 Retention space 58 Ventilation mechanism (relief valve)
59 Pressure switch P1 Specific position

Claims (16)

An expander that extracts power by expanding the working fluid;
A condenser for condensing the working fluid expanded by the expander;
A pump for pressurizing the working fluid condensed in the condenser;
An evaporator that evaporates the heating fluid pressurized by the pump by heating with a heat medium;
A heat medium flow path in which the evaporator is arranged so that the heat medium is supplied to the evaporator, and
The evaporator has an inner tube forming a flow path for the working fluid and an outer tube provided outside the inner tube,
The outer tube has an outer peripheral surface to be heated by the heat medium, and an inner peripheral surface that is partially connected to or in contact with the outer peripheral surface of the inner tube,
A retention space in which gas can stay is formed between the inner peripheral surface of the outer tube and the outer peripheral surface of the inner tube by closing one end of the outer tube,
The outer peripheral surface of the outer pipe includes an upstream heat input surface located on the most upstream side in the flow direction of the heat medium in the heat medium flow path,
The stay space communicates with a space outside the stay space at a specific position where the ambient temperature is lower than the ambient temperature on the upstream heat input surface, or the stay depends on the pressure of the stay space. A ventilation mechanism for communicating the space with the external space is provided in the outer pipe at the specific position.
Rankine cycle equipment.   The Rankine cycle device according to claim 1, wherein the specific position is a position in the heat medium flow path and is located downstream of the upstream heat input surface. The outer pipe has a portion farthest from the upstream heat input surface in the flow direction of the heat medium,
The Rankine cycle apparatus according to claim 2, wherein the most distant portion is at the specific position.   The Rankine cycle apparatus according to claim 1, wherein the specific position is a position outside the heat medium flow path.   The Rankine cycle apparatus according to any one of claims 1 to 4, wherein the other end of the outer tube is at the specific position.   The Rankine cycle apparatus according to claim 1, wherein the outer tube is made of stainless steel.   The Rankine cycle device according to any one of claims 1 to 6, wherein the inner tube is made of copper or a copper alloy. (I) The outer peripheral surface of the inner tube is formed such that a plurality of concave portions and a plurality of convex portions extending in the longitudinal direction of the inner tube are alternately arranged in the circumferential direction of the inner tube, and the plurality of convex portions Is in contact with the inner peripheral surface of the outer tube,
(Ii) The inner peripheral surface of the outer tube is formed such that a plurality of concave portions and a plurality of convex portions extending in the longitudinal direction of the outer tube are alternately arranged in the circumferential direction of the outer tube, and the plurality of convex portions A portion is in contact with the outer peripheral surface of the inner tube,
(Iii) The outer tube or the inner tube is formed in a polygonal tubular shape, and the inner peripheral surface of the outer tube is in contact with the outer peripheral surface of the inner tube at a plurality of positions separated from each other in the circumferential direction of the outer tube. Or (iv) the outer tube having a plurality of ribs that are separated from each other in the circumferential direction of the outer tube, extend in the longitudinal direction of the outer tube, and connect the outer tube and the inner tube to each other. The Rankine cycle device according to any one of claims 1 to 7, wherein a plurality of the retention spaces are formed by integrally molding the inner tube. A pressure switch;
And a control device,
When the pressure switch detects that the pressure in the stay space has risen above a threshold pressure, the control device includes a process including a process for stopping the supply of the heat medium to the heat medium flow path. The Rankine cycle apparatus according to claim 1, wherein the electrical processing is performed. A control device;
A condensing temperature sensor for detecting a condensing temperature of the working fluid in the condenser or a temperature of the working fluid at an outlet of the condenser;
A pump temperature sensor for detecting a temperature of the working fluid at an outlet of the pump;
When the temperature of the working fluid detected by the pump temperature sensor is larger than the threshold of the working fluid detected by the condensing temperature sensor by a threshold value or more, the control device causes the heat flow to the heat medium flow path. The Rankine cycle apparatus according to any one of claims 1 to 8, wherein a predetermined electrical process including a process for stopping the supply of the medium is performed. A control device;
An inlet temperature sensor for detecting the temperature of the working fluid at the inlet of the expander;
When the value detected by the inlet temperature sensor fluctuates periodically, the control device performs a predetermined electrical process including a process for stopping the supply of the heat medium to the heat medium flow path. The Rankine cycle apparatus according to any one of claims 1 to 8.   The Rankine cycle according to any one of claims 9 to 11, wherein the predetermined electrical process includes a process for operating the pump until the supply of the heat medium to the heat medium flow path is stopped. apparatus. An inlet on-off valve provided in the flow path of the working fluid at the inlet of the evaporator;
An outlet on-off valve provided in the flow path of the working fluid at the outlet of the evaporator;
An inlet temperature sensor for detecting the temperature of the working fluid at the inlet of the expander;
And a generator connected to the expander,
The control device drives the generator as an electric motor in a state where the pump is stopped and the inlet on / off valve is closed in place of the predetermined electrical processing or together with the predetermined electrical processing. Thus, a recovery operation for forcibly sending the working fluid in the evaporator to the condenser is executed, and the temperature of the working fluid detected by the inlet temperature sensor during the execution of the recovery operation is a threshold temperature. The electrical process for collection | recovery including the process for closing the said exit opening-and-closing valve and stopping the drive as an electric motor of the said generator is performed when exceeding this, The any one of Claims 9-11 is performed. Rankine cycle equipment. An alarm device,
The Rankine cycle apparatus according to claim 9, wherein the predetermined electrical process includes a process for controlling the alarm device to issue an alarm.   The Rankine cycle according to any one of claims 1 to 14, wherein when the Rankine cycle device is activated, a fan that supplies outside air to the heat medium flow path is operated before the heat medium is generated. apparatus.   The Rankine cycle apparatus according to any one of claims 1 to 15, wherein when the Rankine cycle apparatus is activated, the pump is operated before the heat medium is generated.

Images