JP4140544B2 - Waste heat utilization equipment - Google Patents

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, since these radiators (condensers) exchange heat with the atmosphere, it is desirable that they be provided at a position where a radiator for receiving the traveling wind of the vehicle and a condenser of the vehicle air conditioner are mounted. Thereby, when two heat radiators (condensers) are provided, there is a problem that mountability is inferior. Further, this type of internal combustion engine cooling water circuit is expected to reach a predetermined water temperature in the shortest possible time for warm-up operation immediately after startup.

  Therefore, an object of the present invention is to take the above-mentioned points into consideration, and by combining two Rankine cycle circuits with two different waste heats, the heat efficiency of the waste heat regeneration system as a whole is improved, and the waste heat with good mountability. It is to provide a utilization device.

In order to achieve the above object , the following technical means are adopted. That is, in the first aspect of the present invention, the first heat for exchanging the exhaust gas discharged from the internal combustion engine (10) to the working fluid as high-temperature waste heat among the plurality of waste heats in the internal combustion engine (10). A high-temperature Rankine cycle circuit (100) formed by sequentially connecting a recovery unit (110), a first expander (120), and a first condenser (130) with piping, and a plurality of waste heats in the internal combustion engine (10). Among them, a second heat recovery device (210), a second expander (220), a second heat exchanger for exchanging heat from the hot water heat of the cooling water circuit (20) for cooling the internal combustion engine (10) to the working fluid as low-temperature waste heat . A low-temperature Rankine cycle circuit (200) formed by sequentially connecting a condenser (230) by piping, and the low-temperature Rankine cycle circuit (200) is heat radiated by the high-temperature Rankine cycle circuit (100). As part of the heat source Has use, the cooling water circuit (20) is provided between the downstream side and the second heat recovery unit (210) of the internal combustion engine (10), a first condenser (130) is provided, the first condensing The vessel (130) exchanges heat between the working fluid discharged from the first expander (120) and the cooling water after flowing through the cooling water circuit (20) and cooling the internal combustion engine (10). The cooling water is heated by the heat radiated from one condenser (130) .

According to the first aspect of the invention, in the internal combustion engine (10), for example, there is high-temperature exhaust heat and hot water heat of a cooling water circuit having a temperature lower than that. In the present invention, the heat radiated by the high-temperature Rankine cycle circuit (100) using the high-temperature exhaust heat as a heat source is effectively used on the low-temperature Rankine cycle circuit (200) side, so that the low-temperature Rankine cycle circuit (200 ) Side waste heat regeneration power increases, so that the overall regeneration efficiency of the waste heat regeneration system can be improved.
The cooling water circuit (20) is provided with a first condenser (130) between the downstream side of the internal combustion engine (10) and the second heat recovery unit (210), whereby the first condenser The cooling water in the cooling water circuit (20) for cooling the internal combustion engine (10) can be heated by the heat dissipated in (130). Incidentally, when the hot water heat of the cooling water circuit immediately after the start of the internal combustion engine (10) is cold, the hot water heat is heated by the heat dissipated by the first condenser (130), so that the internal combustion engine (10) is heated. It is possible to shorten the warm-up performance and improve the fuel consumption associated therewith.

In the invention according to claim 2 , the low temperature Rankine cycle circuit (200) stops the low temperature Rankine cycle circuit (200) when the temperature of the low temperature waste heat is low, and the high temperature Rankine cycle circuit (100). It is controlled to operate only. According to invention of Claim 2 , it becomes possible to heat the hot water heat of the cooling water circuit which is a low-temperature waste heat with the heat radiated | emitted by the high temperature Rankine cycle circuit (100) side.

In a third aspect of the invention, the high-temperature Rankine cycle circuit (100) is characterized in that the heat radiated from the first condenser (130) is used as a heat source of the air conditioner. According to the third aspect of the present invention, for example, even in the heater of the vehicle air conditioner that uses the hot water heat of the cooling water circuit as a heating source, when the heater capability cannot be exhibited such as in the extreme cold season, the first condenser The hot water heat of the cooling water circuit can be raised in a short time by the heat radiated at (130).

In invention of Claim 4, it has the heat exchanger (310) which heat-exchanges high temperature waste heat and a heat medium, and heat medium heat-exchanged by the heat exchanger (310) is used for the high temperature Rankine cycle. A high-temperature waste heat transport circuit (300) that is circulated to the first heat recovery device (110) of the circuit (100) is provided, and the first heat recovery device (110) of the high-temperature Rankine cycle circuit (100) It is configured to exchange heat between the working fluid flowing in the Rankine cycle circuit (100) and the heat medium flowing in the high-temperature waste heat transport circuit (300).

According to the fourth aspect of the present invention, exhaust heat that is high-temperature waste heat that fluctuates by providing the high-temperature waste heat transport circuit (300) can be leveled. Thereby, waste heat can be efficiently recovered by the first heat recovery device (110).

The invention according to claim 5 is characterized in that the high-temperature waste heat transport circuit (300) is provided with heat storage means (330) for storing the heat medium heat-exchanged by the heat exchanger (310). . According to invention of Claim 5 , waste heat can be collect | recovered as needed for a waste heat of high temperature with a 1st heat recovery device (110).

The invention according to claim 6 is characterized in that different working fluids are circulated in the high temperature Rankine cycle circuit (100) and the low temperature Rankine cycle circuit (200). According to the invention described in claim 6 , by setting the working fluid according to the temperature of the waste heat to be taken in, waste heat regeneration with high efficiency according to the temperature becomes possible.

In the invention according to claim 7 , the first expander (120) of the high temperature Rankine cycle circuit (100) and the second expander (220) of the low temperature Rankine cycle circuit (200) are regenerated by waste heat energy. It is characterized in that the generated power is output to a common power source. According to the seventh aspect of the invention, the entire waste heat regeneration system can be used as a common power source.

  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 by independent Rankine cycles.

  Specifically, as shown in FIG. 1, 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-rank Rankine cycle circuit 200 uses hot water heat as a heat source for waste heat.

  The high-temperature Rankine cycle circuit 100 includes a first heat recovery device 110, a first expander 120, a first condenser 130, a first liquid receiver 140, and a first pump 150, which are sequentially connected by refrigerant piping. A closed circuit is formed. The high-temperature Rankine cycle circuit 100 is filled with a high-temperature working fluid, and the working fluid is circulated by the electric first pump 150.

  The first heat recovery device 110 is provided in the exhaust pipe 11, and heat that heats the working fluid by exchanging heat between the working fluid sent from the first pump 150 and the exhaust gas flowing through the exhaust pipe 11. It is an exchanger. 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 is a heat exchanger that condenses the working fluid discharged from the first expander 120. In this embodiment, this working fluid is circulated to the primary side, the cooling water that is circulated through the cooling water circuit 20 is circulated to the secondary side, and heat exchange is performed between the working fluid and the cooling water. It is a vessel.

  The first liquid receiver 140 is a receiver for separating the working fluid condensed by the first condenser 130 into a gas-liquid two-phase, and only the separated liquid-phase working fluid is sent to the first pump 150 side. Spill. The first pump 150 pressurizes and pumps the liquid phase working fluid to the first heat recovery unit 110. The rotational driving force generated by the first expander 120 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.

  On the other hand, the low-temperature Rankine cycle circuit 200 includes a second heat recovery unit 210, a second expander 220, a second condenser 230, a second liquid receiver 240, and a second pump 250, which are sequentially connected by refrigerant piping. To form a closed circuit. The low-temperature Rankine cycle circuit 200 is filled with a low-temperature working fluid, 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 this embodiment, this working fluid is circulated to the primary side, the cooling water that circulates through the cooling water circuit 20 is circulated to the secondary side, and heat exchange is performed between the working fluid and the cooling water. It is a vessel.

  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 pressurizes and pumps the liquid phase working fluid to the second heat recovery unit 210. The second expander 220 is connected to the first expander 120 via the power transmission device 41, and the rotational driving force generated by the second expander 220 is generated via the power transmission device 41. Is output. Next, 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, and the secondary side of the first condenser 130 and the secondary side of the second heat recovery unit 210 are connected. ing.

  The radiator 21 is a heat exchanger that cools the cooling water circulated by the hot water pump 22 by heat exchange with the atmosphere. The bypass passage 24 is a passage through which cooling water bypasses the radiator 21, and the amount of cooling water flowing through the radiator 21 and the amount of cooling water bypassing the radiator 21 are adjusted by the thermostat 25.

  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 50.

  The controller 50 receives temperature information from the sensors 12 and 23, and based on these 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 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 includes the high temperature Rankine cycle circuit 200. The circuit 100 is controlled to operate simultaneously with the operation.

  When the coolant temperature detected by the water temperature sensor 23 is equal to or lower than the predetermined temperature, only the low temperature Rankine cycle circuit 200 is controlled to stop. Incidentally, even when the engine 10 is started, such as when the outside air temperature is low, such as in the extreme cold season, only the high-temperature Rankine cycle circuit 100 operates when the cooling water temperature is equal to or lower than the predetermined temperature.

  First, the operation when both the high temperature Rankine cycle circuit 100 and the low temperature Rankine cycle circuit 200 are operated will be described. First, in the high-temperature Rankine cycle circuit 100, the working fluid is pressurized by the first pump 150 and pumped to the first heat recovery device 110, and the working fluid is heated by the high-temperature exhaust gas in the first heat recovery device 110, It becomes superheated steam fluid and is sent to the first expander 120. 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 first condenser 130, the condensed working fluid is separated into two phases by the first receiver 140, and the liquefied working fluid is again supplied to the first pump. To 150. Here, the heat radiation by the condensation of the first condenser 130 heats the cooling water flowing to the secondary side. Thereby, the temperature of the cooling water flowing through the cooling water circuit 20 is raised.

  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. On the other hand, in the low-temperature Rankine cycle circuit 200, the working fluid is pressurized by the second pump 250 and is pumped to the second heat recovery unit 210, and the working fluid is converted into heat generated by driving the engine 10. Heated by hot water heat combined with heat generated by heat radiation from the first condenser 130, becomes superheated steam fluid and is 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.

  When the coolant temperature detected by the water temperature sensor 23 is equal to or lower than the predetermined temperature, the low-temperature Rankine cycle circuit 200 is stopped and only the high-temperature Rankine cycle circuit 100 is operating. The cooling water of the cooling water circuit 20 is heated by the heat dissipated in step (b). 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. Furthermore, even in the heater core of the vehicle air conditioner, when the heater capacity cannot be exhibited such as in the cold season, the hot water in the cooling water circuit can be easily increased.

  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, the heat radiated by the high-temperature Rankine cycle circuit 100 using the high-temperature exhaust heat as a heat source is used as a part of the heat source on the low-temperature Rankine cycle circuit 200 side. The regeneration efficiency of the whole waste heat regeneration system can be increased by increasing the power of waste heat regeneration.

  Specifically, the heat dissipated in the first condenser 130 of the high-temperature Rankine cycle circuit 100 is heated to the hot water heat of the cooling water circuit 20, and the heated hot water heat is used as the low-temperature Rankine cycle circuit 200. By configuring the second heat recovery unit 210 to be used in the above, it is possible to increase the regeneration efficiency of the entire waste heat regeneration system.

  Of the two condensers 130 and 230, the first condenser 130 is provided in the low-temperature Rankine cycle circuit 200 and exchanges heat with the cooling water, thereby exchanging heat with the atmosphere. Only in the vicinity of a condenser of a vehicle radiator or a vehicle air conditioner. Thereby, mountability becomes favorable.

  Further, when the temperature of the cooling water is low, the low-temperature Rankine cycle circuit 200 is stopped and only the high-temperature Rankine cycle circuit 100 is controlled to operate, so that the heat dissipated on the high-temperature Rankine cycle circuit 100 side. Thus, for example, the hot water heat of the cooling water circuit 20 can be heated.

  Specifically, the heat dissipated in the first condenser 130 of the high-temperature Rankine cycle circuit 100 is used as a heat source for warming up the engine 10, so that the hot water heat of the cooling water circuit 20 immediately after the engine 10 is started is By heating the hot water heat with the heat dissipated by the first condenser 130 when it is cooled, the warm-up performance of the engine 10 can be shortened and the accompanying fuel consumption can be improved.

  Furthermore, by using the heat dissipated by the first condenser 130 as a heat source of the vehicle air conditioner, for example, a heater that uses the hot water heat of the cooling water circuit 20 as a heating source cannot exhibit the heater capability such as in the cold season. Sometimes, the hot water heat of the cooling water circuit 20 can be raised in a short time.

  Moreover, the high temperature Rankine cycle circuit 100 and the low temperature Rankine cycle circuit 200 are configured to set the working fluid in accordance with the temperature of the waste heat to be taken in by flowing different working fluids, so that the efficiency according to the temperature is set. High waste heat regeneration is possible. Further, the first expander 120 of the high-temperature Rankine cycle circuit 100 and the second expander 220 of the low-temperature Rankine cycle circuit 200 output the power regenerated by the waste heat energy to the common generator 40. The entire waste heat regeneration system can be used as a common power source.

(Second Embodiment)
In the first embodiment described above, the heat dissipated in the high temperature Rankine cycle circuit 100 is heated by the hot water heat of the cooling water circuit 20 of the engine 10, and the heated hot water heat is used as the low temperature Rankine cycle circuit 200. However, the present invention is not limited to this, and the working fluid on the low-temperature Rankine cycle circuit 200 side may be heated by heat radiated from the high-temperature Rankine cycle circuit 100.

  Specifically, as shown in FIG. 2, the secondary side of the first condenser 130 of the high-temperature Rankine cycle circuit 100 is connected in series with the primary side of the second heat recovery unit 210 of the low-temperature Rankine cycle circuit 200. I am letting. That is, in the first condenser 130, the working fluid of the high temperature Rankine cycle circuit 100 and the working fluid of the low temperature Rankine cycle circuit 200 are subjected to heat exchange. Thereby, the working fluid sent to the second expander 220 of the low-temperature Rankine cycle circuit 200 is heated. Therefore, the regeneration efficiency of the whole waste heat regeneration system can be increased by increasing the power of waste heat regeneration on the low temperature Rankine cycle circuit 200 side.

  In the present 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 of the coolant circuit 20 in the heater of the vehicle air conditioner The effect of the first embodiment that can raise the heat in a short time cannot be expected.

  Therefore, in order to eliminate these problems, the second heat recovery unit 210 is heated with the working fluid flowing in the low-temperature Rankine cycle circuit 200 and the secondary side of the first condenser 130 as shown in FIG. The exchanged working fluid and the hot water heat of the cooling water circuit 20 are configured to exchange heat with each other. In addition, the code | symbol shown in a figure uses the same code | symbol as the thing of the structure similar to 1st Embodiment, and abbreviate | omits description.

  According to this, when the cooling water circuit 20 of the engine 10 is cold, the low temperature Rankine cycle circuit 200 is stopped and only the high temperature Rankine cycle circuit 100 is operated, as in the first embodiment. The hot water heat of the cooling water circuit 20 can be heated. Therefore, 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 in a short time when the heater capacity cannot be exhibited, such as in the severe cold season.

(Third embodiment)
In the above embodiment, the first heat recovery device 110 of the high-temperature Rankine cycle circuit 100 is provided in the exhaust pipe 11 to configure the high-temperature Rankine cycle circuit 100. However, the present invention is not limited to this, and specifically, FIG. As shown, the heat exchanger 310 that exchanges heat between the high-temperature exhaust heat and the heat medium has a heat exchanger 310, and the heat medium heat-exchanged by the heat exchanger 310 is used as the first heat recovery device 110 of the high-temperature Rankine cycle circuit 100. The high-temperature waste heat transport circuit 300 to be circulated may be configured. In addition, 350 shown in the figure is a third pump that pressurizes and pumps the working fluid in the high-temperature waste heat transport circuit 300. Moreover, the working fluid which distribute | circulates the inside of the waste heat transport circuit 300 for high temperature sets the working fluid which does not boil.

  According to this, in the first heat recovery device 110 that recovers the high-temperature waste heat, the working fluid flowing in the high-temperature Rankine cycle circuit 100 and the heat medium flowing in the high-temperature waste heat transport circuit 300 are heat-exchanged. By doing in this way, the exhaust heat which is a fluctuating high temperature waste heat can be equalized. Therefore, waste heat can be efficiently recovered by the first heat recovery device 110.

  Furthermore, as shown in FIG. 5, heat storage means 330 filled with a heat storage agent may be provided in the high-temperature waste heat transport circuit 300. According to this, since the high-temperature waste heat can be stored by the heat storage means 330, the high-temperature waste heat can be recovered by the first heat recovery device 110 as necessary.

(Other embodiments)
In the above-described embodiment, the configuration is such that the rotational driving force regenerated by 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 and charged to 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 the modification of 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 the modification of 3rd Embodiment of this invention.

Explanation of symbols

10. Engine (internal combustion engine)
DESCRIPTION OF SYMBOLS 100 ... Rankine cycle circuit for high temperature 110 ... 1st heat recovery device 120 ... 1st expander 130 ... 1st condenser 200 ... Low temperature Rankine cycle circuit 210 ... 2nd heat recovery device 220 ... 2nd expander 230 ... 2nd Condenser 300 ... High-temperature transport circuit 330 ... Heat storage means

Claims (7)

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;
Of the plurality of waste heats in the internal combustion engine (10), a second heat recovery unit (2) for exchanging heat with the working fluid from the hot water heat of the cooling water circuit (20) for cooling the internal combustion engine (10) as low-temperature waste heat. 210), a second expander (220), and a second condenser (230) are sequentially connected by piping, and a low-temperature Rankine cycle circuit (200) is provided.
The low temperature Rankine cycle circuit (200) uses heat radiated by the high temperature Rankine cycle circuit (100) as a part of a heat source ,
The cooling water circuit (20) is provided with the first condenser (130) between the downstream side of the internal combustion engine (10) and the second heat recovery unit (210),
The first condenser (130) includes a working fluid discharged from the first expander (120), cooling water after flowing through the cooling water circuit (20) and cooling the internal combustion engine (10), The waste water utilization apparatus is characterized in that the cooling water is heated by heat exchanged by the first condenser (130) . The low temperature Rankine cycle circuit (200) stops the low temperature Rankine cycle circuit (200) and operates only the high temperature Rankine cycle circuit (100) when the temperature of the low temperature waste heat is low. waste heat utilization device according to claim 1, characterized in that it is controlled. The high-temperature Rankine cycle circuit (100), waste heat recovery device according to claim 2, the heat is radiated by the first condenser (130) is characterized in that it is utilized as a heat source of the air conditioner. A heat exchanger (310) for exchanging heat between the high-temperature waste heat and the heat medium is provided, and the heat medium heat-exchanged by the heat exchanger (310) is converted into the first rank of the high-temperature Rankine cycle circuit (100). 1 A high-temperature waste heat transport circuit (300) for circulation to the heat recovery device (110) is provided,
The first heat recovery unit (110) of the high temperature Rankine cycle circuit (100) includes a working fluid flowing in the high temperature Rankine cycle circuit (100) and heat flowing in the high temperature waste heat transport circuit (300). The waste heat utilization apparatus according to any one of claims 1 to 3, wherein the waste heat utilization apparatus is configured to exchange heat with a medium . The waste according to claim 4 , wherein the high-temperature waste heat transport circuit (300) is provided with heat storage means (330) for storing a heat medium heat-exchanged by the heat exchanger (310). Heat utilization device. The waste according to any one of claims 1 to 5 , wherein different working fluid flows through the high temperature Rankine cycle circuit (100) and the low temperature Rankine cycle circuit (200). Heat utilization device. The first expander (120) of the high temperature Rankine cycle circuit (100) and the second expander (220) of the low temperature Rankine cycle circuit (200) share the power regenerated by waste heat energy. The waste heat utilization apparatus according to any one of claims 1 to 6, wherein the waste heat utilization apparatus is output to a power source .

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