JP2005273543A - Waste heat utilization device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a waste heat utilization device providing excellent mountability by combining two Rankine cycle circuits capable of commonly using two different kinds of waste heat. <P>SOLUTION: The waste heat utilization device is equipped with: a Rankine cycle circuit 100 for high temperatures comprising a first heat recovering device 110 performing heat exchange of exhaust gas emitted from an engine 10 with a working fluid, a first expander 120, and a first condenser 130, which are connected by pipes in series; and a Rankine cycle circuit 200 for low temperatures comprising a second heat recovering device 210 performing heat exchange of hot water heat of the cooling water circuit of the engine 10 with the working fluid, a second expander 220, and a second condenser 230, which are connected by pipes in series. Rankine cycle circuits 100, 200 are configured so as to commonly use the first condenser 130 and the second condenser 230, which are integrally formed. Thus, excellent mountability is achieved. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a waste heat utilization device that regenerates power by using waste heat in a heat engine or a heat generating auxiliary machine, and particularly relates to a configuration of a Rankine cycle circuit that regenerates waste heat in two different temperature fields. .

  Conventionally, as this type of waste heat utilization device, for example, those disclosed in Patent Literature 1 and Patent Literature 2 are known as technologies for regenerating waste heat of an internal combustion engine such as an automobile. In Patent Document 1, exhaust heat of exhaust gas exhausted from an internal combustion engine is used as waste heat, and in order to regenerate the waste heat, a Rankine cycle circuit is formed using the components of the refrigeration cycle. The exhaust heat is recovered as power by a certain expander, and the recovered power is added to the compressor of the vehicle air conditioner.

In Patent Document 2, the hot water heat of the cooling water circuit that cools the internal combustion engine is used as waste heat, and in order to regenerate the waste heat, a Rankine cycle circuit is formed as in Patent Document 1, and hot water heat is generated by an expander. Is recovered as power, and the recovered power is added to the compressor of the vehicle air conditioner (see, for example, Patent Document 1 and Patent Document 2).
JP 56-43019 A Japanese Patent Laid-Open No. 56-43018

  However, according to the above-mentioned patent document, each is a waste heat regeneration technology for one waste heat. For example, as a technology for regenerating waste heat in two different temperature fields such as exhaust heat and hot water heat, Rankine cycle circuit A technique of forming each independently is conceivable. However, in this case, two radiators (condensers) constituting the Rankine cycle circuit are required.

  Moreover, these radiators (condensers) are generally formed so as to exchange heat with the outside air in order to improve the heat dissipation characteristics, and are mounted with a radiator for receiving the traveling wind of the vehicle or a condenser for the vehicle air conditioner. It is desirable to be provided at a certain position. Thereby, when two heat radiators (condensers) are provided, there is a problem that mountability is inferior. Moreover, this type of internal combustion engine cooling water circuit is expected to reach a predetermined water temperature in as short a time as possible during warm-up operation immediately after startup.

  Then, the objective of this invention is in view of the said point, and is providing the waste heat utilization apparatus with favorable mounting property by combining the two Rankine cycle circuits which can share two different waste heats. .

  In order to achieve the above object, the technical means according to claims 1 to 7 are employed. That is, according to the first aspect of the present invention, the first heat recovery device (110) and the first expander (for exchanging heat of the high-temperature waste heat with the working fluid among the plurality of waste heat in the heat engine or the heat generating auxiliary machine ( 120), a high-temperature Rankine cycle circuit (100) in which the first condenser (130) is sequentially connected by piping, and a plurality of waste heat in a heat engine or heat-generating auxiliary machine, low-temperature waste heat is used as a working fluid. A low-temperature Rankine cycle circuit (200) in which a second heat recovery unit (210), a second expander (220), and a second condenser (230) for heat exchange are sequentially connected by piping, The Rankine cycle circuit (100) and the low-temperature Rankine cycle circuit (200) are characterized in that the first condenser (130) and the second condenser (230) are formed integrally and shared. .

  According to the first aspect of the present invention, when the waste heat is regenerated in this type of Rankine cycle, the first condenser (130) and the second condenser (230) are radiated with heat due to the condensation of the working fluid. In the present invention, by sharing these condensers (130, 230), the mountability can be improved as compared with the case where two condensers (130, 230) are provided.

  In the second aspect of the present invention, the first heat recovery unit that exchanges the exhaust gas discharged from the internal combustion engine (10) with the working fluid as high-temperature waste heat among the plurality of waste heats in the internal combustion engine (10). (110), a first expander (120), a first condenser (130) sequentially connected by piping, a high-temperature Rankine cycle circuit (100), and a plurality of waste heat in the internal combustion engine (10), A second heat recovery unit (210), a second expander (220), and a second condenser (230) that exchange heat from the hot water of the cooling water circuit that cools the internal combustion engine (10) as working waste fluid as low-temperature waste heat. And a low-temperature Rankine cycle circuit (200) in which the first condenser (130) and the second low-rank Rankine cycle circuit (200) are connected to each other. One with the condenser (230) Formed on and is characterized by being configured to share.

  According to the invention described in claim 2, in the internal combustion engine (10), for example, there is high-temperature exhaust heat and hot water heat of the cooling water circuit having a temperature lower than that. In the present invention, a high-temperature Rankine cycle circuit (100) using high-temperature exhaust heat as a heat source and a low-temperature Rankine cycle circuit (200) using hot water heat lower than that as a heat source are provided, and each condenser (130 , 230), the mountability can be improved as compared with the case where two condensers (130, 230) are provided.

  In the invention according to claim 3, the high temperature Rankine cycle circuit (100) is configured such that the discharge side of the first expander (120) is connected to the suction side of the second expander (220), and the low temperature Rankine cycle circuit (200). When the operation is stopped, the second heat recovery unit (210) on the upstream side of the second expander (220) is condensed.

  According to the third aspect of the present invention, the heat dissipated on the high temperature Rankine cycle circuit (100) side is heat-exchanged with the low temperature waste heat side to heat the low temperature waste heat. As a result, the warm-up performance of the internal combustion engine (10) can be shortened and the fuel consumption associated therewith can be improved.

  Further, the heater of the vehicle air conditioner can also raise the hot water heat of the cooling water circuit in a short time when the heater capacity cannot be exhibited, such as in the severe cold season. On the other hand, when both Rankine cycle circuits (100, 200) are operating at the same time, they can be expanded in the second expander (220) after being expanded in the first expander (120). Can improve the regeneration efficiency of waste heat.

  In the invention according to claim 4, the high temperature Rankine cycle circuit (100) and the low temperature Rankine cycle circuit (200) are formed by integrally forming the first expander (120) and the second expander (220). It is characterized by being configured to be shared. Specifically, according to the invention described in claim 4, by providing the downstream side of the second heat recovery device (210) in the middle of the expansion process of the first expander (120), the second expander ( 220) can be dispensed with separately. Thereby, mountability can be improved rather than providing two expanders (120, 220).

  In the invention described in claim 5, the high-temperature Rankine cycle circuit (100) and the low-temperature Rankine cycle circuit (200) are condensed into the first heat recovery device (110) and the second heat recovery device (210), respectively. The first pump (150) and the second pump (250) for pumping the working fluid are provided.

  According to the fifth aspect of the present invention, the pressure increase according to the temperature field of the waste heat in each of the first heat recovery device (110) and the second heat recovery device (210) is, for example, according to the temperature of the waste heat. Therefore, it can be easily adjusted by controlling the rotational speed.

  In the invention described in claim 6, the high-temperature Rankine cycle circuit (100) and the low-temperature Rankine cycle circuit (200) are condensed into the first heat recovery device (110) and the second heat recovery device (210), respectively. The working fluid pressurized by the second pump (250) is supplied to either the second pump (250) for pumping the working fluid and the first heat recovery device (110) or the second heat recovery device (210). A flow rate adjusting means (260) for adjusting the flow rate is provided.

  According to the sixth aspect of the present invention, the first heat recovery device (110) and the second heat recovery device can be obtained by replacing one of the two pumps (150, 250) with the flow rate adjusting means (260). The pressure increase according to the temperature field of each waste heat of (210) can be adjusted. Thereby, while being able to reduce parts cost rather than the above-mentioned Claim 5, since the flow volume adjustment means (260) can be reduced in size rather than a 1st 1st pump (150), mounting property can be improved.

  In the seventh aspect of the invention, the high temperature Rankine cycle circuit (100) and the low temperature Rankine cycle circuit (200) are controlled so that the two Rankine cycle circuits (100, 200) are operated simultaneously or one of them. It is characterized by doing. According to the seventh aspect of the present invention, the waste heat regeneration from two different temperature fields can be easily and selectively performed among the waste heat in the heat engine or the heat generating auxiliary machine.

  In addition, the code | symbol in the bracket | parenthesis of each said means shows a corresponding relationship with the specific means of embodiment mentioned later.

(First embodiment)
Hereinafter, the waste heat utilization apparatus in 1st Embodiment of this invention is demonstrated based on FIG. FIG. 1 is a schematic diagram showing an overall configuration of a waste heat utilization apparatus in which the present invention is applied to an internal combustion engine (hereinafter referred to as an engine) 10 that is a heat engine of an automobile. The waste heat utilization apparatus of this embodiment performs waste heat regeneration by forming waste heat in two different temperature fields in two Rankine cycles.

  Specifically, exhaust heat discharged from the engine 10 and warm water heat of the cooling water flowing in the cooling water circuit 20 that cools the engine 10 are used as heat sources for waste heat. In other words, the high-temperature Rankine cycle circuit 100 uses exhaust heat as a heat source for waste heat, and the low-temperature Rankine cycle circuit 200 uses hot water heat as a heat source for waste heat. However, some components among the components constituting the Rankine cycle circuit are configured to be shared.

  More specifically, as shown in FIG. 1, first, the low temperature Rankine cycle circuit 200 includes a second heat recovery device 210, a second expander 220, a second condenser 230, a second liquid receiver 240, and It consists of the second pump 250, and these are sequentially connected by a refrigerant pipe to form a closed circuit. A working fluid is sealed inside the low-temperature Rankine cycle circuit 200, and the working fluid is circulated by the electric second pump 250.

  The second heat recovery unit 210 is provided in the vicinity of the cooling water circuit 20, and exchanges heat between the working fluid sent from the second pump 250 and the cooling water flowing through the cooling water circuit 20. Heat exchanger for heating. In the present embodiment, the counter flow type in which the working fluid is circulated to the primary side, the cooling water circulated through the cooling water circuit 20 is circulated to the secondary side, and the working fluid and the cooling water (warm water heat) are heat-exchanged. It is a heat exchanger.

  The second expander 220 is a fluid device that generates a rotational driving force by the expansion of the superheated steam working fluid heated by the second heat recovery unit 210. The second condenser 230 is a heat exchanger that condenses and liquefies the working fluid discharged from the second expander 220 by heat exchange with the atmosphere. The second liquid receiver 240 is a receiver for separating the working fluid condensed by the second condenser 230 into a gas-liquid two phase, and only the separated liquid-phase working fluid is sent to the second pump 250 side. Spill.

  The second pump 250 is a pump for boosting and pumping the liquid phase working fluid to the second heat recovery unit 210, and is set to operate at a predetermined rotational speed. The second expander 220 is connected to a first expander 120, which will be described later, via a power transmission device 41, and the rotational driving force generated by the second expander 220 generates power via the power transmission device 41. Is output to the machine 40.

  The cooling water circuit 20 is provided with a radiator 21, a hot water pump 22, a bypass passage 24, a thermostat 25, and the like. The radiator 21 is a heat exchanger that circulates cooling water from the engine 100 by a hot water pump 22 and cools it by heat exchange between the cooling water and the atmosphere. The bypass passage 24 is a passage that bypasses the radiator 21, and the amount of cooling water that flows through the radiator 21 and the amount of cooling water that bypasses the radiator 21 are adjusted by the thermostat 25.

  On the other hand, the Rankine cycle circuit for high temperature 100 includes a first heat recovery device 110, a first expander 120, a first condenser 130 (shared with the second condenser 230), and a first liquid receiver 140 (first 2) and a second pump 250 and a first pump 150, which are sequentially connected by a refrigerant pipe to form a closed circuit. In the present embodiment, the discharge side of the first expander 120 is connected between the suction side of the second expander 220 and the second heat recovery unit 210 so that the first condenser 130 is connected to the second condenser 230. To share with. In the high-temperature Rankine cycle circuit 100, the working fluid is circulated by the electric first pump 150 and the second pump 250.

  The first heat recovery device 110 is provided in the exhaust pipe 11 and operates by exchanging heat between the working fluid sent from the first pump 150 and the second pump 250 and the exhaust gas flowing through the exhaust pipe 11. It is a heat exchanger that heats a fluid. The first expander 120 is a fluid device that generates a rotational driving force by the expansion of the superheated steam working fluid heated by the first heat recovery device 110. The first condenser 130 and the first liquid receiver 140 are shared with the second condenser 230 and the second liquid receiver 240 as described above, and the low-temperature Rankine cycle circuit 200 is operated simultaneously. Sometimes it is distributed.

  That is, when only the high-temperature Rankine cycle circuit 100 is operating while the low-temperature Rankine cycle circuit 200 side is stopped, the working fluid expanded and depressurized by the first expander 120 is transferred to the second heat recovery unit 210 side. The condensed water is sent to the first heat recovery device 110. At this time, the working fluid expanded and depressurized by the first expander 120 is configured to be condensed by the second heat recovery unit 210. At this time, the second pump 250 is stopped.

  When operating simultaneously with the low temperature Rankine cycle circuit 200 side, the working fluid expanded and depressurized by the first expander 120 is the second expander 220, the first condenser 130, the first liquid receiver 140, the second The heat is sent to the first heat recovery device 110 via the pump 250 and the first pump 150. During this simultaneous operation, the working fluid expanded and depressurized by the first expander 120 is expanded again by the second expander 120 and then condensed by the first condenser 130. The second pump 250 is a pump that pressurizes and pumps the liquid-phase working fluid to the first heat recovery device 110 and the second heat recovery device 210, and is set to a predetermined rotational speed in the same manner as the first pump 150. ing.

  The rotational driving force generated in the first expander 120 and the second expander 220 is output to the generator 40 via the power transmission device 41. The generator 40 is connected to the battery 43 via the inverter 42, and the battery 43 is charged with the generated power generated by the generator 40.

  In the figure, 12 is an exhaust temperature sensor for detecting the exhaust temperature of the exhaust gas flowing in the exhaust pipe 11, and 23 is a water temperature sensor for detecting the temperature of the cooling water flowing through the cooling water circuit. Each of these sensors 12 and 23 is connected to output detected temperature information to the control device 60.

  The control device 60 receives temperature information from the sensors 12 and 23, and based on the temperature information, operates the first and second pumps 150 and 250, the hot water pump 22 and the inverter 42 described above. The charging of the generated power from the generator 40 is controlled. Although not shown, the cooling water circuit 20 is formed so that the cooling water is circulated through a heater core provided in the vehicle air conditioner.

  Next, the operation of the waste heat utilization apparatus having the above configuration will be described. First, the high temperature Rankine cycle circuit 100 side operates when the engine 10 is started and the exhaust gas temperature detected by the exhaust temperature sensor 12 is equal to or higher than a predetermined temperature, and the low temperature Rankine cycle circuit 200 side is a water temperature sensor. It is controlled so that it operates when the water temperature detected by 23 is above a predetermined temperature.

  Incidentally, when the outside air temperature is low such as in the cold season, only the high-temperature Rankine cycle circuit 100 is operated when the cooling water temperature is equal to or lower than the predetermined temperature even when the engine 10 is started. Both Rankine cycle circuits 100 and 200 are controlled to operate when the temperature is exceeded.

  First, when only the high temperature Rankine cycle circuit 100 side operates, the working fluid is pressurized by the first pump 150 being actuated and pumped to the first heat recovery unit 110, and the working fluid in the first heat recovery unit 110 is operated. Is heated by the high-temperature exhaust gas and is sent to the first expander 120 as superheated steam fluid. In the first expander 120, the working fluid is expanded and reduced in an isentropic manner, and part of the heat energy and pressure energy is converted into a rotational driving force.

  The decompressed gasified working fluid is condensed and liquefied by the second heat recovery unit 210, and the condensed working fluid flows out to the first pump 150. Thereby, the rotational driving force generated by the first expander 120 rotates the generator 40 via the power transmission device 41. Then, the battery 43 is charged with the generated power generated by the generator 40. Moreover, the cooling water which distribute | circulates to the secondary side is heated by the 2nd heat recovery device 210, and the water temperature of the cooling water which distribute | circulates the cooling water circuit 20 is raised.

  As a result, it is possible to shorten the warm-up performance immediately after the engine 10 is started and to improve the fuel consumption associated therewith. Further, the heater core of the vehicle air conditioner can also easily increase the hot water in the cooling water circuit when the heater capability cannot be exhibited such as in the cold season.

  When the coolant temperature of the coolant circuit 20 reaches a predetermined temperature or higher, the low-temperature Rankine cycle circuit 200 operates. That is, both Rankine cycle circuits 100 and 200 operate simultaneously. On the low-temperature Rankine cycle circuit 200 side, the working fluid is pressurized by the operation of the second pump 250 and is pumped to the second heat recovery unit 210, and the working fluid is the hot water of the cooling water circuit 20 in the second heat recovery unit 210. Heated by heat, becomes superheated steam fluid and sent to the second expander 220. In the second expander 220, the working fluid is expanded and reduced in an isentropic manner, and part of the heat energy and pressure energy is converted into a rotational driving force.

  The decompressed gasified working fluid is condensed and liquefied by the second condenser 230, the condensed working fluid is separated into two phases by the second receiver 240, and the liquefied working fluid is again supplied to the second pump. To 250. Here, the heat released by the condensation of the second condenser 230 is exchanged with the atmosphere. The rotational driving force generated by the second expander 220 rotates the generator 40 via the power transmission device 41. Then, the battery 43 is charged with the generated power generated by the generator 40.

  On the other hand, on the high temperature Rankine cycle circuit 100 side, the working fluid decompressed by the first expander 120 is expanded again by the second expander 220 to generate a rotational driving force. The decompressed gasified working fluid is condensed and liquefied by the second condenser 230, the condensed working fluid is separated into two phases by the second receiver 240, and the liquefied working fluid is converted into the second pump 250. The pressure is increased and flows out again to the first pump 150.

  Thereby, the waste heat of the exhaust heat can be recovered by the first heat recovery device 110, and the waste heat of the two different temperature fields of the hot water heat can be recovered by the second heat recovery device 210, and the waste heat regeneration is caused by the waste heat. it can. When the low-temperature Rankine cycle circuit 200 is operating, the thermostat 25 adjusts the amount of cooling water flowing through the radiator 21 so that the cooling water temperature of the cooling water circuit 20 does not exceed a predetermined temperature. Yes.

  In the present embodiment, the operations of the low temperature Rankine cycle circuit 200 and the high temperature Rankine cycle circuit 100 are automatically controlled based on the temperature information from the water temperature sensor 23 and the exhaust temperature sensor 12. You may operate | move by selecting either so that it may operate | move simultaneously or only one may be operated. Furthermore, in this embodiment, the first heat receiver 140 is shared with the second heat receiver 240, but the first heat receiver 140 is provided in the high-temperature Rankine cycle circuit 100, that is, upstream of the first pump 150. Also good.

  According to the waste heat utilization apparatus according to the first embodiment described above, the engine 10 that is a heat engine has, for example, high-temperature exhaust heat and hot water heat of the cooling water circuit 20 having a temperature lower than that. In the present invention, a high-temperature Rankine cycle circuit 100 using high-temperature exhaust heat as a heat source and a low-temperature Rankine cycle circuit 200 using hot water heat lower than that are used as heat sources, and the condensers 130 and 230 are shared. Thus, the mountability can be improved as compared with the case where the two condensers 130 and 230 are provided.

  Specifically, the high-temperature Rankine cycle circuit 100 is configured such that when the discharge side of the first expander 120 is connected to the suction side of the second expander 220 and the low-temperature Rankine cycle circuit 200 side is not operating, By being configured to be condensed by the second heat recovery unit 210, the hot water heat of the cooling water circuit 20 can be heated by the second heat recovery unit 210 by the heat radiated on the high temperature Rankine cycle circuit 100 side. . Thereby, the warm-up performance of the engine 10 can be shortened and the fuel consumption associated therewith can be improved.

  Further, even in the heater of the vehicle air conditioner, the hot water heat of the cooling water circuit 20 can be raised in a short time when the heater capacity cannot be exhibited, such as in the severe cold season. On the other hand, when both Rankine cycle circuits 100 and 200 are operating simultaneously, they can be expanded in the second expander 220 after being expanded in the first expander 120, so that the regeneration efficiency of the high-temperature waste heat is increased. Can be increased.

  The high-temperature Rankine cycle circuit 100 and the low-temperature Rankine cycle circuit 200 include a first pump 150 and a second pump 250 that pump the working fluid condensed in the first heat recovery device 110 and the second heat recovery device 210, respectively. Is provided, the pressure increase according to the temperature field of the waste heat in each of the first heat recovery device 110 and the second heat recovery device 210 is, for example, changing the number of rotations according to the temperature of the waste heat. It can be easily adjusted by control.

  The high-rank Rankine cycle circuit 100 and the low-temperature Rankine cycle circuit 200 control the two Rankine cycle circuits 100 and 200 so that either one of them operates or one of them operates, so that exhaust gas out of waste heat in the engine 10 is exhausted. Waste heat regeneration from two different temperature fields such as heat and hot water heat can be easily and selectively performed.

(Second Embodiment)
In the first embodiment described above, the first expander 120 on the high temperature Rankine cycle circuit 100 side and the second expander 220 on the low temperature Rankine cycle circuit 200 side are connected to generate the rotational driving force. Not limited to this, the first expander 120 and the second expander 220 may be integrally configured. Specifically, as shown in FIG. 2, the first expander 120 is integrally formed without providing the second expander 220, and an intermediate outlet 120a is provided in the middle of the expansion process, and this intermediate outlet 120a is provided. And the downstream side of the second heat recovery unit 210 are connected.

  Based on the operation on the low temperature Rankine cycle circuit 200 side, that is, when the low temperature Rankine cycle circuit 200 side is in a stopped state, the working fluid expanded by the first expander 120 is discharged from the intermediate outlet 120a to the second heat. When the low temperature Rankine cycle circuit 200 side is in an operating state, the working fluid expanded by the first expander 120 is expanded again and sent to the second condenser 230 side.

  According to the above configuration, the second expander 220 can be provided separately by connecting the downstream end of the second heat recovery unit 210 to the intermediate extraction port 120a in the middle of the expansion process in the first expander 120. It can be unnecessary. Thereby, mountability can be improved rather than providing two expanders 120 and 220.

(Third embodiment)
In the above embodiment, the first expander 120 and the second expander 220 are connected or integrally configured so that the working fluid expanded and depressurized by the first expander 120 is expanded again. Not limited to this, as shown in FIG. 3, the discharge side of the second expander 220 may be connected to the discharge side of the first expander 120 and connected to the second condenser 230. According to this, each of the first expander 120 and the second expander 220 can generate a rotational driving force independently.

  Further, the discharge side of the first expander 120 and the suction side of the second expander 220 are connected, and an on-off valve 160 is provided in the middle thereof. When the low-temperature Rankine cycle circuit 200 is stopped, the on-off valve 160 is You may control to open a valve. According to this, when the water temperature of the cooling water circuit 20 is below a predetermined temperature, the cooling water of the cooling water circuit 20 can be heated by the second heat recovery device 210. As a result, as in the first embodiment, the warm-up performance of the engine 10 can be shortened and the fuel consumption associated therewith can be improved. Further, the heater of the vehicle air conditioner can also raise the hot water heat of the cooling water circuit 20 in a short time when the heater capacity cannot be exhibited such as in the cold season.

(Other embodiments)
In the above embodiment, the first pump 150 and the second pump 250 that pump the condensed working fluid are provided in the first heat recovery device 110 and the second heat recovery device 210, respectively. As shown in FIG. 4, the first pump 150 on the upstream side of the first heat recovery unit 110 may be abolished and a flow rate adjustment valve 260 that is a flow rate adjusting means may be provided on the upstream side of the second heat recovery unit 210.

  The flow rate adjustment valve 260 is a valve that adjusts the flow rate according to the valve opening, and distributes the flow rate between the first heat recovery device 110 and the second heat recovery device 210 according to the output of the second pump 250 and the valve opening. Set with. In addition, according to the above configuration, by eliminating the first pump 150 and replacing it with the flow rate control valve 260, the cost of parts can be reduced as compared with the case where the two pumps 150 and 250 of the above embodiment are provided. Since the flow rate adjustment valve 260 can be made smaller than the first pump 150, the mountability can be improved.

  However, in this embodiment, when the coolant circuit immediately after the engine 10 is started is cooled, the warm-up performance of the engine 10 is shortened, the fuel consumption is improved, and the warm water heat of the coolant circuit 20 in the heater of the vehicle air conditioner. It is not possible to expect the effect of the first embodiment that can raise the temperature in a short time.

  In the above embodiment, the rotational driving force recovered from the waste heat in the high temperature Rankine cycle circuit 100 and the low temperature Rankine cycle circuit 200 is output to the generator 40 to charge the battery 43. For example, the compressor of a vehicle air conditioner may be driven or used as a power source for other purposes.

  In the above embodiment, the exhaust heat and the hot water heat of the cooling water circuit out of the waste heat of the engine 10 that is the heat engine are used as the heat sources of the waste heat, and the high temperature Rankine cycle circuit 100 and the low temperature Rankine cycle circuit 200 are used. Although it was configured to regenerate waste heat, the present invention is not limited to this. For example, waste heat of a fuel cell mounted on a fuel cell vehicle, or a vehicle other than a fuel cell includes, for example, an electric motor, an electric pump, an inverter Among the waste heats of the heat-generating auxiliary machines that generate heat by the operation, the waste heats of two different temperature fields for high temperature and low temperature may be combined.

It is a schematic diagram which shows the whole structure of the waste-heat utilization apparatus in 1st Embodiment of this invention. It is a schematic diagram which shows the whole structure of the waste-heat utilization apparatus in 2nd Embodiment of this invention. It is a schematic diagram which shows the whole structure of the waste-heat utilization apparatus in 3rd Embodiment of this invention. It is a schematic diagram which shows the whole structure of the waste heat utilization apparatus in other embodiment.

Explanation of symbols

10. Engine (internal combustion engine)
DESCRIPTION OF SYMBOLS 100 ... High temperature Rankine cycle circuit 110 ... 1st heat recovery device 120 ... 1st expander 130 ... 1st condenser 150 ... 1st pump 200 ... Low temperature Rankine cycle circuit 210 ... 2nd heat recovery device 220 ... 2nd expansion Machine 230 ... second condenser 250 ... second pump 260 ... flow rate regulating valve (flow rate regulating means)

Claims (7)

A first heat recovery unit (110), a first expander (120), and a first condenser (130) for exchanging heat of high-temperature waste heat with a working fluid among a plurality of waste heat in a heat engine or a heat generating auxiliary machine. A high-temperature Rankine cycle circuit (100) connected by sequential piping;
A second heat recovery unit (210), a second expander (220), and a second condenser (230) for exchanging heat of the low-temperature waste heat to a working fluid among a plurality of waste heats in the heat engine or heat generation auxiliary machine. A low temperature Rankine cycle circuit (200) connected by sequential piping,
The high temperature Rankine cycle circuit (100) and the low temperature Rankine cycle circuit (200) are configured such that the first condenser (130) and the second condenser (230) are integrally formed and shared. Waste heat utilization device characterized by that. A first heat recovery device (110) and a first expander for exchanging heat of exhaust gas exhausted from the internal combustion engine (10) as a high-temperature waste heat to a working fluid among a plurality of waste heats in the internal combustion engine (10). (120), a high-temperature Rankine cycle circuit (100) formed by sequentially connecting the first condenser (130) by piping;
A second heat recovery unit (210) for exchanging heat from the plurality of waste heat in the internal combustion engine (10) to the working fluid using hot water heat of a cooling water circuit that cools the internal combustion engine (10) as low-temperature waste heat; A low-temperature Rankine cycle circuit (200) formed by sequentially connecting a second expander (220) and a second condenser (230) by piping;
The high temperature Rankine cycle circuit (100) and the low temperature Rankine cycle circuit (200) are configured such that the first condenser (130) and the second condenser (230) are integrally formed and shared. Waste heat utilization device characterized by that.   In the high temperature Rankine cycle circuit (100), the discharge side of the first expander (120) is connected to the suction side of the second expander (220), and the low temperature Rankine cycle circuit (200) side stops operating. 3. The apparatus according to claim 1, wherein the second heat recovery unit is configured to be condensed in the second heat recovery unit on the upstream side of the second expander. Waste heat utilization equipment.   The high temperature Rankine cycle circuit (100) and the low temperature Rankine cycle circuit (200) are configured so that the first expander (120) and the second expander (220) are formed integrally. The waste heat utilization apparatus according to any one of claims 1 to 3, wherein the waste heat utilization apparatus is provided.   The high temperature Rankine cycle circuit (100) and the low temperature Rankine cycle circuit (200) pump the working fluid condensed in each of the first heat recovery unit (110) and the second heat recovery unit (210). The waste heat utilization apparatus according to any one of claims 1 to 4, wherein a first pump (150) and a second pump (250) are provided.   The high temperature Rankine cycle circuit (100) and the low temperature Rankine cycle circuit (200) pump the working fluid condensed in each of the first heat recovery unit (110) and the second heat recovery unit (210). The flow rate of the working fluid boosted by the second pump (250) to either the second pump (250) and the first heat recovery unit (110) or the second heat recovery unit (210). The waste heat utilization apparatus according to any one of claims 1 to 4, further comprising a flow rate adjusting means (260) for adjusting.   The high temperature Rankine cycle circuit (100) and the low temperature Rankine cycle circuit (200) are controlled such that two Rankine cycle circuits (100, 200) are operated simultaneously or one of them. The waste heat utilization apparatus as described in any one of Claims 1 thru | or 6.

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