JP2014231737A - Rankine cycle device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a Rankine cycle device capable of preventing thermal decomposition of a working fluid and an oil, and being designed while degrading heat resistance of pipes and an expander.SOLUTION: An engine 10 has an exhaust pipe 30 in which an exhaust gas is circulated, the exhaust pipe 30 has a main flow channel 30a passing through a boiler 113, a bypass flow channel 30b bypassing the boiler 113, and a flow rate control valve 31 disposed in the bypass flow channel 30b and controlling a flow rate of the exhaust gas circulated in the bypass flow channel 30b. An ECU 119 detects a charging rate of the battery 118, and controls an opening of the flow rate control valve 31 on the basis of an integrated map, so that the flow rate of the exhaust gas circulated in the main flow channel 30a is controlled.

Description

  The present invention relates to a Rankine cycle apparatus including a Rankine cycle, and more particularly to a Rankine cycle apparatus mounted on a vehicle.

  A technique using a Rankine cycle that converts heat discharged from an internal combustion engine of a vehicle into power of a generator or the like has been developed. The Rankine cycle consists of a boiler that generates superheated steam by isobaric heating of a liquid phase fluid, an expander that obtains power by adiabatic expansion of the superheated steam, and steam that is expanded in the expander is cooled by isobaric pressure. And a pump for sending the liquefied liquid phase fluid to the boiler.

  Patent Document 1 describes a Rankine cycle circuit mounted on a vehicle. In this Rankine cycle circuit, the drive shaft of the pump and the output shaft of the expander are arranged coaxially via an electromagnetic clutch, and the engine power is transmitted to the pump drive shaft via another electromagnetic clutch. It is configured to be. The expander is further connected to a generator via another electromagnetic clutch, and the generator is connected to a battery. Then, depending on the state of the vehicle, the three electromagnetic clutches are engaged or released, and the operations of the pump, the expander, and the generator are controlled, thereby controlling the operation and power generation of the Rankine cycle circuit.

  In a Rankine cycle mounted on a vehicle, when the pump and the expander are continuously operated and the power generated by the generator is continuously charged to the battery, the amount of power charged to the battery is consumed by the vehicle. If there are more, the battery will continue to increase its charge and will end up in an overcharged state, which is an overcharged state. In the Rankine cycle circuit of Patent Document 1, the electromagnetic clutch between the expander and the generator is released to stop the operation of the generator and adjust the amount of power generation, thereby preventing the battery from being overcharged.

JP 2009-274513 A

  However, the Rankine cycle circuit of Patent Document 1 requires a space for mounting an electromagnetic clutch, and there is a problem that it is difficult to secure a space in a vehicle on which many other equipments are mounted.

  The present invention has been made to solve such problems, and an object thereof is to provide a Rankine cycle device capable of preventing overcharging of a battery with a simple configuration.

The Rankine cycle device according to the present invention is a Rankine cycle device mounted on a vehicle, in which a heat exchanger that heats the working fluid by an exhaust heat medium of a vehicle engine and a working fluid heated by the heat exchanger are expanded. Rankine cycle having an expander that obtains regenerative energy, a condenser that cools the working fluid discharged from the expander, and a pump that sends the working fluid cooled by the condenser to the heat exchanger, and the regenerative energy obtained by the expander The power generation means for converting the power into power, the power storage means for storing the power converted by the power generation means, the charge rate detection means for detecting the charge rate of the power stored in the power storage means, and the detection value by the charge rate detection means And a heat absorption amount control means for controlling the amount of heat absorption from the exhaust heat medium to the working fluid. The heat absorption amount control means controls the amount of regenerative energy obtained by the expander by controlling the amount of heat absorption from the exhaust heat medium to the working fluid. As a result, the amount of electric power supplied to the power storage means is adjusted.
The Rankine cycle device according to the present invention is a Rankine cycle device mounted on a vehicle, in which a heat exchanger that heats the working fluid by an exhaust heat medium of a vehicle engine and a working fluid heated by the heat exchanger are expanded. Rankine cycle having an expander that obtains regenerative energy, a condenser that cools the working fluid discharged from the expander, and a pump that sends the working fluid cooled by the condenser to the heat exchanger, and the regenerative energy obtained by the expander Power generation means for converting the power into the electric power, power storage means for storing the power converted by the power generation means, charge rate detection means for detecting the charge rate of the power stored in the power storage means, and the working fluid flowing into the expander A temperature detection means for detecting temperature; a bypass path for communicating a first path for communicating the pump with the expander; and a second path for communicating the expander with the pump; A bypass flow rate control valve provided in the bypass path and capable of opening and closing the bypass route, a control means for controlling opening and closing of the bypass flow rate control valve based on a detection value by the charging rate detection means, and a temperature detection means And an endothermic amount control means for controlling an endothermic amount from the exhaust heat medium to the working fluid based on the detected value.
The heat absorption amount control means includes a waste heat medium main passage for allowing the exhaust heat medium to flow into the heat exchanger, a waste heat medium bypass passage for allowing the waste heat medium to bypass the heat exchanger, and a waste heat medium main passage. And waste heat medium flow control means for controlling the flow of the waste heat medium in the waste heat medium bypass flow path.
The heat absorption amount control means includes a working fluid main channel for the working fluid to flow into the heat exchanger, a working fluid bypass channel for the working fluid to bypass the heat exchanger, a working fluid main channel and the working fluid bypass flow. Working fluid flow control means for controlling the flow of the working fluid in the channel.

  According to the present invention, the amount of regenerative energy obtained by the expander is adjusted by controlling the amount of heat absorbed from the exhaust heat medium to the working fluid based on the value detected by the charge rate detection unit. Since the amount of power supplied to the power storage means is adjusted, overcharging of the power storage means can be prevented with a simple configuration.

It is a schematic diagram which shows the Rankine-cycle apparatus which concerns on Embodiment 1 of this invention, and the structure of the periphery. It is a schematic diagram which shows the Rankine-cycle apparatus which concerns on Embodiment 2, and the structure of the periphery. It is a schematic diagram which shows the Rankine cycle apparatus which concerns on Embodiment 3, and the structure of the periphery. It is a schematic diagram which shows the Rankine-cycle apparatus which concerns on Embodiment 4, and the structure of the periphery.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
Embodiment 1 FIG.
As shown in FIG. 1, a vehicle (not shown) including an engine 10 includes a Rankine cycle device 101 having a Rankine cycle 100. The Rankine cycle 100 includes a pump 111, a boiler 113, an expander 114, and a condenser 115, and a coolant that is a working fluid circulates in the Rankine cycle 100.

  The boiler 113 is a heat exchanger that performs heat exchange between the exhaust gas discharged from the engine 10 and the refrigerant circulating in the Rankine cycle 100. The engine 10 includes an exhaust pipe 30 through which exhaust gas flows, and the exhaust pipe 30 is provided in a main flow path 30a that passes through the boiler 113, a bypass flow path 30b that bypasses the boiler 113, and a bypass flow path 30b. A flow rate control valve 31 for controlling the flow rate of the exhaust gas flowing through the bypass flow path 30b. Of the exhaust gas flowing through the exhaust pipe 30, only the exhaust gas flowing through the main flow path 30 a exchanges heat with the refrigerant circulating in the Rankine cycle 100 in the boiler 113. Here, the exhaust gas is an exhaust heat medium for causing the refrigerant circulating in the Rankine cycle 100 to absorb the exhaust heat of the engine 10, the main flow path 30 a constitutes the exhaust heat medium main flow path, and the bypass flow path 30 b is exhausted. A heat medium bypass flow path is configured, and the flow rate control valve 31 forms exhaust heat medium flow control means. The main flow path 30a, the bypass flow path 30b, and the flow rate control valve 31 constitute an endothermic amount control means for controlling the endothermic amount from the exhaust gas to the refrigerant.

  The expander 114 is connected to a motor generator 116 operable as a generator or an electric motor via an expander drive shaft 114a. The motor generator 116 is connected to the pump 111 via a pump drive shaft 111a. The pump drive shaft 111a and the expander drive shaft 114a are coupled so as to be able to transmit each other's rotational drive force within the motor generator 116. Further, motor generator 116 is electrically connected to inverter device 117, and further, inverter device 117 is electrically connected to battery 118. Here, the motor generator 116 constitutes a power generation means, and the battery 118 constitutes a power storage means.

  The Rankine cycle apparatus 101 includes an ECU 119 that is a control unit. ECU 119 is electrically connected to battery 118 and can detect the charging rate of battery 118. Here, the ECU 119 constitutes a charging rate detection unit. The ECU 119 is also electrically connected to the flow control valve 31 and controls the opening degree of the flow control valve 31. The ECU 119 has a built-in map of the charging rate of the battery 118 and the opening of the flow control valve 31 so that the opening of the flow control valve 31 can be controlled based on the charging rate of the battery 118.

Next, the operation of the Rankine cycle apparatus 101 according to the first embodiment of the present invention will be described.
When the engine 10 is operated, the pump 111 is operated and the refrigerant circulates through the Rankine cycle 100. Exhaust gas is discharged from the engine 10 to the exhaust pipe 30, and among the exhausted exhaust gas, the exhaust gas having a flow rate corresponding to the opening degree of the flow control valve 31 flows through the main flow path 30 a and then returns to the exhaust pipe 30. The exhaust gas that has flowed through the bypass flow path 30b joins and is discharged to the outside of the vehicle. And the exhaust gas which distribute | circulates this flow path 30a performs heat exchange with the refrigerant | coolant which distribute | circulates the Rankine cycle 100 in the boiler 113. FIG.

  The liquid refrigerant pumped by the pump 111 is heated at an equal pressure by heat exchange with the exhaust gas in the boiler 113, evaporates, becomes high-temperature / high-pressure superheated steam, and flows out of the boiler 113. The superheated steam refrigerant flowing out of the boiler 113 flows into the expander 114. In the expander 114, the refrigerant in the state of high-temperature and high-pressure superheated steam undergoes adiabatic expansion, and the expansion energy of the refrigerant when changing from the high-pressure state to the low-pressure state is converted into rotational energy as regenerative energy. Accordingly, in the expander 114, a further rotational driving force is applied to a rotating body (not shown) that is rotationally driven by the motor generator 116, and this rotational driving force is transmitted to the motor generator 116 and the pump driving shaft via the expander driving shaft 114a. 111a. The pump 111 is driven by the rotational driving force transmitted from the expander 114 via the expander drive shaft 114a and the pump drive shaft 111a, and the motor generator 116 moves the expander drive shaft 114a from the expander 114. It is driven by the rotational driving force transmitted through it and operates as a generator to generate an alternating current. Then, the alternating current generated by motor generator 116 is converted into direct current by inverter device 117 and then charged to battery 118.

  The refrigerant that has passed through the expander 114 becomes a high-temperature and low-pressure state, is discharged from the expander 114, and flows into the capacitor 115. In the condenser 115, the refrigerant is cooled by isobaric cooling by exchanging heat with the surrounding air, that is, outside air, and becomes a liquid. The refrigerant that has become liquid is sucked into the pump 111 and pumped again by the pump 111 to circulate through the Rankine cycle 100.

  During operation of Rankine cycle apparatus 101, ECU 119 continues to detect the charging rate of battery 118. When the charging rate of the battery 118 reaches a predetermined amount (less than 100%), the ECU 119 controls the flow rate control valve 31 to prevent overcharging in which the battery 118 is further charged even after the charging rate reaches 100%. Operate to open. As the charging rate of the battery 118 increases, the ECU 19 increases the opening degree of the flow control valve 31 based on the built-in map. Thereby, the flow rate of the exhaust gas flowing through the bypass flow path 30b is increased. By increasing the flow rate, the flow rate of the exhaust gas flowing through the main flow path 30a decreases. As a result, the amount of heat absorbed from the exhaust gas to the refrigerant in the boiler 113 decreases, so the amount of regenerative energy obtained by the expander 114 decreases and the amount of power supplied to the battery 118 also decreases. As a result, overcharging of the battery 118 is prevented.

  As described above, the ECU 119 controls the flow rate of the exhaust gas flowing into the boiler 113 based on the charging rate of the battery 118, and controls the amount of heat absorbed from the exhaust gas to the refrigerant in the boiler 113. The amount of regenerative energy that is obtained is adjusted, and as a result, the amount of power supplied to the battery 118 is adjusted, so that overcharging of the battery 118 can be prevented with a simple configuration.

Embodiment 2. FIG.
Next, a Rankine cycle device according to Embodiment 2 of the present invention will be described. In the following embodiments, the same reference numerals as those in FIG. 1 are the same or similar components, and detailed description thereof will be omitted.
The Rankine cycle device according to Embodiment 2 of the present invention is obtained by changing a system for suppressing the occurrence of overcharge in battery 118 with respect to Embodiment 1.

  As shown in FIG. 2, in the Rankine cycle 100, a path that connects the pump 111 and the boiler 113 is a path 1a, and a path that connects the boiler 113 and the expander 114 is a path 1b. Further, a path connecting the expander 114 and the capacitor 115 is a path 2a, and a path connecting the capacitor 115 and the pump 111 is a path 2b. Here, the path 1 a and the path 1 b form the first path 1, and the path 2 a and the path 2 b form the second path 2.

  The Rankine cycle 100 has a bypass path 3 that connects the first path 1 to the second path 2. One end of the bypass path 3 is connected to the path 1 a of the first path 1, and the other end of the bypass path 3 is connected to the path 2 a of the second path 2. In addition, the Rankine cycle 100 includes a bypass flow rate control valve 120 including an electromagnetic valve that can open or close the bypass path 3 and adjust the flow path cross-sectional area of the bypass path 3 in the middle of the bypass path 3. ing. The ECU 119 is electrically connected to the bypass flow control valve 120 and can control the opening and closing operations of the bypass flow control valve 120. Further, the path 1b is provided with a temperature sensor 32 which is a temperature detecting means for detecting the temperature of the refrigerant flowing into the expander 114, and the ECU 119 is also electrically connected to the temperature sensor 32. The ECU 119 has a built-in map of the detected value of the temperature sensor 32 and the opening of the flow control valve 31 so that the ECU 119 can control the opening of the flow control valve 31 based on the detected value by the temperature sensor 32. Yes. Other configurations are the same as those of the first embodiment.

Next, the operation of the Rankine cycle apparatus 101 according to the second embodiment of the present invention will be described.
The operation in which motor generator 116 generates electric power by operating Rankine cycle 100 and the generated electric power is charged in battery 118 is the same as that in the first embodiment. In the second embodiment, the occurrence of overcharge in battery 118 is suppressed by the following operation.

  During operation of Rankine cycle 100, ECU 119 continues to detect the charging rate of battery 118. When the charging rate of the battery 118 reaches a predetermined amount (less than 100%), the ECU 119 detects the bypass flow rate control valve 120 in order to prevent overcharging in which the battery 118 is further charged even after the charging rate reaches 100%. Operate to release. At this time, a part of the refrigerant passes through the bypass path 3 from the path 1a through which the high-pressure refrigerant immediately after being pumped by the pump 111 flows to the path 2a through which the low-pressure refrigerant after being decompressed by the expander 114 flows. Circulate. As a result, the amount of refrigerant flowing into the expander 114 decreases. Furthermore, the pressure of the refrigerant in the path 1b is reduced due to the decrease in the refrigerant flow rate, and the differential pressure between the refrigerant inflow side and the outflow side in the expander 114 is reduced.

  Therefore, since the amount of regenerative energy that the expander 114 obtains as work by expanding the refrigerant flowing into the expander 114 decreases, the amount of power supplied to the battery 118 decreases. At this time, the regenerative energy of the expander 114 is reduced by increasing the opening of the bypass flow control valve 120 to increase the flow path cross-sectional area of the bypass path 3 and increasing the flow rate of the refrigerant flowing through the bypass path 3. The amount increases.

  However, when the flow rate of the refrigerant flowing through the bypass path 3 is increased, the flow rate of the refrigerant flowing into the boiler 113 is decreased, so that the temperature of the superheated vapor refrigerant flowing out of the boiler 113 is increased. If the temperature of the refrigerant of the superheated steam becomes too high, the refrigerant and oil may be thermally decomposed, and further, the heat resistance of the paths 1b and 2b and the expander 114 needs to be designed to be high. Therefore, the ECU 119 controls the opening degree of the flow control valve 31 based on the built-in map, and the flow rate of the exhaust gas flowing through the main flow path 30a is controlled. Schematically, if the detected value of the temperature sensor 32 becomes high, the opening degree of the flow control valve 31 is increased, and the flow rate of the exhaust gas flowing through the bypass flow channel 30b is increased, thereby circulating the main flow channel 30a. Reduce exhaust gas flow. Then, in the boiler 113, the amount of heat absorbed from the exhaust gas to the refrigerant decreases, so the temperature of the refrigerant flowing out of the boiler 113 decreases. Conversely, if the detected value of the temperature sensor 32 is low, the amount of heat absorbed from the exhaust gas to the refrigerant is reduced by decreasing the opening of the flow control valve 31 and increasing the flow rate of the exhaust gas flowing through the main flow path 30a. Since it increases, the temperature of the refrigerant flowing out of the boiler 113 rises. Thereby, the fluctuation | variation of the temperature of the refrigerant | coolant which flows in into the expander 114 is suppressed.

  In this way, based on the charging rate of the battery 118, the ECU 119 controls the amount of refrigerant flowing into the expander 114 by controlling the flow rate of the refrigerant flowing through the bypass path 3, so that the regenerative energy obtained by the expander 114 is obtained. As a result, the amount of electric power supplied to the battery 118 is adjusted, so that overcharging of the battery 118 can be prevented with a simple configuration. Further, when the flow rate of the refrigerant flowing through the bypass path 3 is changed, the amount of refrigerant flowing into the boiler 113 is also changed, and the temperature of the refrigerant flowing into the expander 114 varies, but based on the detection value by the temperature sensor 32, The ECU 119 controls the flow rate of the exhaust gas flowing into the boiler 113 and controls the amount of heat absorbed from the exhaust gas to the refrigerant in the boiler 113, whereby the temperature fluctuation of the refrigerant flowing into the expander 114 can be suppressed. . That is, in the second embodiment, the power generation amount and the refrigerant temperature can be controlled independently.

  In the first and second embodiments, the flow control valve 31 is provided in the bypass flow path 30b, and controls the flow rate of the exhaust gas flowing through the main flow path 30a by controlling the flow rate of the exhaust gas flowing through the bypass flow path 30b. However, the present invention is not limited to this configuration, and the flow control valve 31 may be provided in the main flow path 30a. Further, although the flow rate control valve 31 for controlling the flow rate of the exhaust gas flowing through the bypass flow path 30b is used as the exhaust heat medium flow control means, the present invention is not limited to this. A three-way valve that allows exhaust gas to flow only through either the main flow path 30a or the bypass flow path 30b may be used. In this case, instead of a map of the charging rate of the battery 118 or the detected value of the temperature sensor 32 and the opening degree of the flow control valve 31, the ECU 119 has a charging rate of the battery 118 or a detected value by the temperature sensor 32. When the charging rate of the battery 118 or the value detected by the temperature sensor 32 is equal to or higher than this upper limit value, the exhaust gas flows through the bypass passage 30b by switching the three-way valve. The heat absorption from the exhaust gas to the refrigerant is stopped.

  In the second embodiment, the value detected by the temperature sensor 32 is transmitted to the ECU 119, and the ECU 119 controls the opening degree of the flow control valve 31 based on the map built in the ECU 119. However, the present embodiment is limited to this embodiment. It is not a thing. You may make it control the opening degree of the flow control valve 31 so that the detection value by the temperature sensor 32 may not exceed the preset upper limit value without interposing operation | movement of ECU119.

Embodiment 3 FIG.
Next, a Rankine cycle device according to Embodiment 3 of the present invention will be described.
The Rankine cycle device according to Embodiment 3 of the present invention is different from Embodiment 1 in the form of the endothermic amount control means for controlling the amount of heat absorbed from the exhaust gas to the refrigerant.

  As shown in FIG. 3, the exhaust pipe 30 is provided so as to pass through the boiler 113. The high-pressure path 50 from the pump 111 to the expander 114 of the Rankine cycle 100 is provided in the main flow path 40a that passes through the boiler 113, the bypass flow path 40b that bypasses the boiler 113, and the bypass flow path 40b. And a flow rate control valve 41 for controlling the flow rate of the refrigerant flowing through the. Here, the main flow path 40a constitutes a working fluid main flow path, the bypass flow path 40b constitutes a working fluid bypass flow path, and the flow rate control valve 41 constitutes a working fluid flow control means. The main flow path 40a, the bypass flow path 40b, and the flow rate control valve 41 constitute endothermic amount control means for controlling the amount of heat absorbed from the exhaust gas to the refrigerant.

The ECU 119 is electrically connected to the flow control valve 41, and controls the opening rate of the flow control valve 41 based on the charging rate of the battery 118. And a built-in map about.
Other configurations are the same as those of the first embodiment.

Next, the operation of the Rankine cycle apparatus 101 according to the third embodiment of the present invention will be described.
When the engine 10 is operated, the pump 111 is operated and the refrigerant circulates through the Rankine cycle 100. In the liquid refrigerant pumped by the pump 111, the refrigerant having a flow rate corresponding to the opening degree of the flow control valve 41 flows through the main flow path 40a, and the rest flows through the bypass flow path 40b. On the other hand, exhaust gas is discharged from the engine 10 to the exhaust pipe 30, and the exhaust gas flows through the exhaust pipe 30, whereby the exhaust gas flows into the boiler 113. In the boiler 113, the exhaust gas exchanges heat with the refrigerant flowing through the main flow path 40a.

  The liquid refrigerant flowing through the main flow path 40 a is heated by isobaric heat exchange with the exhaust gas in the boiler 113, evaporates, becomes high-temperature and high-pressure superheated steam, and flows out of the boiler 113. The superheated steam refrigerant flowing out of the boiler 113 and the liquid refrigerant flowing through the bypass passage 40b are merged and mixed. The liquid refrigerant evaporates due to the heat of the superheated steam refrigerant, and the temperature of the superheated steam refrigerant is lowered by heating the liquid refrigerant. As a result, the superheated steam refrigerant is lower than the temperature of the superheated steam refrigerant immediately after flowing out of the boiler 113. The subsequent operation, that is, the operation from when the refrigerant flows into the expander 114 until it is sucked into the pump 111, and the regenerative energy obtained by the expander 114, the motor generator 116 generates power and the battery 118 is charged. The operation is the same as in the first embodiment.

  During operation of Rankine cycle apparatus 101, ECU 119 continues to detect the charging rate of battery 118. When the charging rate of the battery 118 reaches a predetermined amount (less than 100%) or more, the ECU 119 sets the flow control valve 41 to prevent overcharging in which the battery 118 is further charged even after the charging rate reaches 100%. Operate to open. The ECU 19 increases the opening degree of the flow rate control valve 41 based on the built-in map as the charging rate of the battery 118 increases, thereby increasing the flow rate of the refrigerant flowing through the bypass flow path 40b. As a result, the flow rate of the refrigerant flowing through the main flow path 40a decreases. Then, in the boiler 113, the heat exchange efficiency between the exhaust gas and the refrigerant decreases, and the amount of heat absorbed from the exhaust gas to the refrigerant decreases, so the amount of regenerative energy obtained by the expander 114 decreases, and the electric power supplied to the battery 118 The amount is also reduced. As a result, overcharging of the battery 118 is prevented.

  Thus, based on the charging rate of the battery 118, the ECU 119 controls the amount of heat absorbed from the exhaust gas to the refrigerant in the boiler 113 by controlling the flow rate of the refrigerant flowing into the boiler 113. Since the amount of regenerative energy to be obtained is adjusted and, as a result, the amount of power supplied to battery 118 is adjusted, the same effect as in the first embodiment can be obtained. Further, as compared with the first and second embodiments, the exhaust heat medium (exhaust gas) is not bypassed, but the refrigerant flowing into the boiler 113 is bypassed. The engine load can be reduced without fluctuations.

Embodiment 4 FIG.
Next, a Rankine cycle device according to Embodiment 4 of the present invention will be described.
The Rankine cycle device according to Embodiment 4 of the present invention is obtained by changing a system for suppressing the occurrence of overcharge in battery 118 with respect to Embodiment 3.

  As shown in FIG. 4, the Rankine cycle 100 has a bypass path 3 that connects the first path 1 to the second path 2. One end of the bypass path 3 is connected to the path 1 a of the first path 1, and the other end of the bypass path 3 is connected to the path 2 a of the second path 2. In addition, the Rankine cycle 100 includes a bypass flow rate control valve 120 including an electromagnetic valve that can open or close the bypass path 3 and adjust the flow path cross-sectional area of the bypass path 3 in the middle of the bypass path 3. ing. The ECU 119 is electrically connected to the bypass flow control valve 120 and can control the opening and closing operations of the bypass flow control valve 120. Further, the path 1b is provided with a temperature sensor 32 which is a temperature detecting means for detecting the temperature of the refrigerant flowing into the expander 114, and the ECU 119 is also electrically connected to the temperature sensor 32. The ECU 119 has a built-in map of the detected value of the temperature sensor 32 and the opening of the flow control valve 31 so that the ECU 119 can control the opening of the flow control valve 31 based on the detected value by the temperature sensor 32. Yes. Other configurations are the same as those of the third embodiment.

  The operation of Rankine cycle 100 and the operation in which motor generator 116 generates power and battery 118 is charged are the same as in the third embodiment. Further, the operation for suppressing the occurrence of overcharge in the battery 118 and the operation for suppressing the temperature fluctuation of the refrigerant flowing into the expander 114 are the same as those in the second embodiment. Therefore, the Rankine cycle device according to the fourth embodiment can also obtain the same effects as those of the second embodiment.

  In the third and fourth embodiments, the flow control valve 41 is provided in the bypass flow path 40b, and controls the flow rate of the refrigerant flowing through the main flow path 40a by controlling the flow rate of the refrigerant flowing through the bypass flow path 40b. However, the present invention is not limited to this configuration, and the flow control valve 41 may be provided in the main flow path 40a. Moreover, although the flow control valve 41 which controls the flow volume of the refrigerant | coolant which distribute | circulates the bypass flow path 40b was used as an exhaust heat medium flow control means, it is not limited to this. A three-way valve that allows the refrigerant to flow through only one of the main flow path 40a and the bypass flow path 40b may be used. In this case, instead of a map of the charging rate of the battery 118 or the detected value of the temperature sensor 32 and the opening of the flow control valve 41, the ECU 119 has a charging rate of the battery 118 or a detected value by the temperature sensor 32. When the charging rate of the battery 118 or the value detected by the temperature sensor 32 is equal to or higher than this upper limit value, the refrigerant flows through the bypass passage 40b by switching the three-way valve, Stop heat absorption from the exhaust gas to the refrigerant.

  In the fourth embodiment, the value detected by the temperature sensor 32 is transmitted to the ECU 119, and the ECU 119 controls the opening degree of the flow control valve 41 based on the map built in the ECU 119. However, the present embodiment is limited to this embodiment. It is not a thing. You may make it control the opening degree of the flow control valve 41 so that the detection value by the temperature sensor 32 may not exceed the preset upper limit value without interposing operation | movement of ECU119.

In the first to fourth embodiments, the exhaust gas discharged from the engine 10 is used as the exhaust heat medium for causing the refrigerant circulating in the Rankine cycle 100 to absorb the exhaust heat of the engine 10. However, the present invention is limited to this. is not. The cooling water that cools the engine 10 may be used as the exhaust heat medium, and heat may be exchanged between the cooling water and the refrigerant in the boiler 113. Further, both exhaust gas and cooling water may be used. In this case, two boilers are provided, a boiler using the exhaust heat medium as exhaust gas and a boiler using the exhaust heat medium as cooling water. Any one of the heat absorption amount control means according to the first to fourth embodiments is provided.
In the first to fourth embodiments, a configuration in which exhaust gas or refrigerant is bypassed with respect to the boiler is adopted as the heat absorption amount control means. However, the present invention is not limited to this. For example, cooling water is added to the exhaust gas introduced into the boiler. It is possible to employ appropriate means such as jetting to forcibly reduce the temperature of the exhaust gas.

  DESCRIPTION OF SYMBOLS 1 1st path | route, 2nd path | route, 3 bypass path | route, 10 engine, 30a main flow path (exhaust heat medium main flow path), 30b bypass flow path (exhaust heat medium bypass flow path), 31 flow control valve (exhaust heat medium flow) Control means), 32 temperature sensor (temperature detection means), 40a main flow path (working fluid main flow path), 40b bypass flow path (working fluid bypass flow path), 41 flow control valve (working fluid flow control means), 100 Rankine cycle , 101 Rankine cycle device, 111 pump, 113 boiler (heat exchanger), 114 expander, 115 condenser, 116 motor generator (power generation means), 118 battery (power storage means), 119 ECU (control means), 120 bypass flow rate control valve.

Claims (4)

In the Rankine cycle device mounted on a vehicle,
A heat exchanger that heats a working fluid by an exhaust heat medium of a vehicle engine, an expander that expands the working fluid heated by the heat exchanger to obtain regenerative energy, and a working fluid discharged from the expander A Rankine cycle having a condenser for cooling and a pump for sending the working fluid cooled by the condenser to the heat exchanger;
Power generation means for converting the regenerative energy obtained by the expander into electric power;
Power storage means for storing the electric power converted by the power generation means;
Charging rate detection means for detecting the charging rate of the electric power stored in the power storage means;
A Rankine cycle device comprising: an endothermic amount control means for controlling an endothermic amount from the exhaust heat medium to the working fluid based on a detection value by the charging rate detection means. In the Rankine cycle device mounted on a vehicle,
A heat exchanger that heats a working fluid by an exhaust heat medium of a vehicle engine, an expander that expands the working fluid heated by the heat exchanger to obtain regenerative energy, and a working fluid discharged from the expander A Rankine cycle having a condenser for cooling and a pump for sending the working fluid cooled by the condenser to the heat exchanger;
Power generation means for converting the regenerative energy obtained by the expander into electric power;
Power storage means for storing the electric power converted by the power generation means;
Charging rate detection means for detecting the charging rate of the electric power stored in the power storage means;
Temperature detecting means for detecting the temperature of the working fluid flowing into the expander;
A bypass path communicating a first path communicating the pump to the expander and a second path communicating the expander to the pump;
A bypass flow control valve provided in the bypass path and capable of opening and closing the bypass path;
Control means for controlling opening and closing of the bypass flow rate control valve based on a detection value by the charging rate detection means;
A Rankine cycle device comprising: an endothermic amount control means for controlling an endothermic amount from the exhaust heat medium to the working fluid based on a detection value by the temperature detecting means. The endothermic amount control means includes
An exhaust heat medium main flow path for allowing the exhaust heat medium to flow into the heat exchanger;
An exhaust heat medium bypass flow path for the exhaust heat medium to bypass the heat exchanger;
The Rankine cycle apparatus according to claim 1, further comprising: a waste heat medium flow control unit configured to control a flow of the waste heat medium in the waste heat medium main flow path and the waste heat medium bypass flow path. The endothermic amount control means includes
A working fluid main flow path for the working fluid to flow into the heat exchanger;
A working fluid bypass passage for the working fluid to bypass the heat exchanger;
The Rankine cycle apparatus according to claim 1, further comprising a working fluid flow control unit that controls a flow of the working fluid in the working fluid main flow path and the working fluid bypass flow path.

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