JP4823936B2 - Waste heat utilization apparatus and control method thereof - Google Patents

Description

  The present invention relates to a waste heat utilization apparatus that recovers waste heat from a heat engine such as a vehicle engine and a control method therefor.

Conventionally, in a vehicle equipped with a Rankine cycle, for example, as described in Patent Document 1, the Rankine cycle is operated only when the temperature of engine cooling water (waste heat) is equal to or higher than a predetermined temperature, and waste heat is When it was not enough, the Rankine cycle was stopped. As a result, the temperature of the engine can be prevented from excessively decreasing, and the waste heat can be recovered without reducing the fuel consumption rate of the engine.
JP 2005-155336 A

  However, in a vehicle such as a hybrid vehicle or an idle stop vehicle where the engine may be stopped depending on driving conditions, a mechanical pump driven by the engine is used as a pump for circulating engine cooling water. When the engine is stopped, the engine cooling water does not circulate. Therefore, even if the Rankine cycle is operated only based on the temperature of the engine cooling water as in the technique described in Patent Document 1, it does not function as a waste heat recovery system. There was a problem.

  In view of the above problems, an object of the present invention is to provide a waste heat utilization apparatus that enables reliable waste heat recovery and a control method thereof.

  In order to achieve the above object, the present invention employs the following technical means.

According to the first aspect of the present invention, the working fluid in the cycle is heated by the heater (34) by the waste heat fluid accompanying the waste heat of the heat engine (10), and the heated working fluid is expanded by the expander (110). The Rankine cycle (30A) for recovering the mechanical energy by expanding the fluid and condensing and liquefying the expanded working fluid in the condenser (21), and the control means (40) for controlling the operation of the Rankine cycle (30A) ,
A rotational speed detection means (15) for detecting the rotational speed of the heat engine (10);
The compressor (110, 130), which is also used as the expander (110) or arranged in parallel to the expander (110), is formed so as to share the condenser (21), and the control means (40). A waste heat utilization device having a refrigeration cycle (20A) controlled by
The control means (40) grasps the operating state of the heat engine (10) from the rotational speed obtained from the rotational speed detection means (15), and grasps the flow state of the waste heat fluid from the operating state of the heat engine (10). When the temperature of the waste heat fluid is equal to or higher than the predetermined temperature (Tw1, Tw2) and the waste heat fluid is in a fluid state, the Rankine cycle (30A) is activated and the refrigeration cycle (20A) is activated. In this case, if the temperature of the waste heat fluid is equal to or higher than a predetermined temperature (Tw1, Tw2), the compressor (110, 130) is controlled to be turned on and off, and the Rankine cycle is performed when the compressor (110, 130) is turned off. (30A) is actuated .

Thus, by determining not only the temperature of the waste heat fluid of the heat engine (10) but also whether or not the waste heat fluid is in a flow state, the Rankine cycle ( 30A) can be operated, so that waste heat can be recovered efficiently and the fuel consumption rate of the vehicle can be improved.
The control means (40) can grasp the flow state of the waste heat fluid according to the operating state of the heat engine (10). At this time, if the operating state of the heat engine (10) is grasped from the rotational speed obtained from the rotational speed detection means (15) for detecting the rotational speed of the heat engine (10), the operating state of the heat engine (10) is obtained. Can be surely grasped.
Moreover, in the thing which has a refrigerating cycle (20A), even if it is an operating condition of a refrigerating cycle (20A), the state which turns off a compressor (110, 130) is produced, and a Rankine cycle (30A) is operated in the meantime Therefore, waste heat recovery can be performed more efficiently, and the fuel consumption rate of the vehicle can be improved.
As in the invention described in claim 2, when the compressor (110, 130) is turned on, the control means (40) compresses the compressor so that the cooling capacity of the refrigeration cycle (20A) exceeds the required cooling capacity. It is preferable to increase the discharge amount of (110, 130). Thereby, since the cool storage effect can be obtained and the time for which the compressors (110, 130) are turned off can be extended, the operable time of the Rankine cycle (30A) can be extended and effective waste heat recovery can be achieved. .
At this time, as in the invention described in claim 3, the control means (40) requires the temperature of the working fluid in the evaporator (24) of the refrigeration cycle (20A) or the temperature of other parts related thereto. It is preferable to increase the discharge amount of the compressors (110, 130) so that the second cooling temperature (TEO2) is lower than the first cooling temperature (TEO1) that satisfies the cooling capability.

In the invention described in claim 4 , the working fluid in the cycle is heated by the heater (34) by the waste heat fluid accompanying the waste heat of the heat engine (10), and the heated working fluid is expanded by the expander (110). The Rankine cycle (30A) for recovering the mechanical energy by expanding the hydraulic fluid in a) and condensing and liquefying the expanded working fluid in the condenser (21);
Control means (40) for controlling the operation of the Rankine cycle (30A);
A rotational speed detection means (15) for detecting the rotational speed of the heat engine (10);
A refrigeration cycle (20B) that is provided with a dedicated compressor (130), is formed by sharing a condenser (21), and can be independently controlled with respect to the Rankine cycle (30A) by the control means (40). ) and, in the waste heat utilization device for it has a,
The control means (40) grasps the operating state of the heat engine (10) from the rotational speed obtained from the rotational speed detection means (15), and grasps the flow state of the waste heat fluid from the operating state of the heat engine (10). When the temperature of the waste heat fluid is equal to or higher than the predetermined temperature (Tw1, Tw2) and the waste heat fluid is in a fluid state, the Rankine cycle (30A) is activated and the refrigeration cycle (20B) is activated. In this case, when the temperature of the waste heat fluid is equal to or higher than a predetermined temperature (Tw1, Tw2) and the waste heat fluid is in a fluid state, the refrigeration cycle (20B) and the Rankine cycle (30A) are operated simultaneously. It is said.

Thus, not only the temperature of the waste heat fluid of the heat engine (10) but also whether or not the waste heat fluid is in a fluid state is also determined, so that when the waste heat recovery is possible, the Rankine cycle (30A ) Can be operated, so that waste heat can be recovered efficiently and the fuel consumption rate of the vehicle can be improved.
The control means (40) can grasp the flow state of the waste heat fluid according to the operating state of the heat engine (10). At this time, if the operating state of the heat engine (10) is grasped from the rotational speed obtained from the rotational speed detection means (15) for detecting the rotational speed of the heat engine (10), the operating state of the heat engine (10) is obtained. Can be surely grasped.
And efficient waste-heat recovery is attained, operating a refrigerating cycle (20B), and the fuel consumption rate of a vehicle can be improved.

In the invention described in claim 4 , as in the invention described in claim 5 , the control means (40) includes the first heat radiation amount required for condensation of the working fluid discharged from the compressor (130), and expansion. The operating rotational speed of the expander (110) is set so that the sum of the second heat radiation amount required for condensing the working fluid flowing out of the compressor (110) is equal to or less than the heat dissipation capability during condensation in the condenser (21). It is good to control.

  Thereby, the simultaneous operation of the refrigeration cycle (20B) and the Rankine cycle (30A) is possible without causing the heat dissipation function of the condenser (21) to fail.

As in the sixth aspect of the invention, the predetermined temperatures (Tw1, Tw2) may be set so as to have hysteresis by the first predetermined temperature (Tw1) and the second predetermined temperature (Tw2) higher than the first predetermined temperature (Tw1). . As a result, hunting for temperature determination in the vicinity of the predetermined temperatures (Tw1, Tw2) can be prevented, and stable Rankine cycle (30A) switching control can be performed.
As in the invention described in claim 7, the waste heat fluid is cooling water for cooling the heat engine (10), and this cooling water is supplied by a mechanical pump (12) driven by the heat engine (10). When circulating to the heater (34), the flow state of the cooling water can be grasped by grasping the operating state of the heat engine (10).
The heat engine (10) is suitable for an internal combustion engine (10) for a vehicle as in the invention described in claim 8 .

The specific vehicle may be a hybrid vehicle in which the internal combustion engine (10) is activated or stopped according to a traveling condition, or an idle stop vehicle as in the ninth aspect of the invention.

  As a result, even when the internal combustion engine (10) is stopped, the Rankine cycle (30A) can be reliably operated based on the temperature and flow state of the waste heat fluid, and the fuel consumption rate of the vehicle is improved. be able to.

The invention according to claims 10 to 18 relates to a control method in the waste heat utilization apparatus, and the technical significance thereof is essentially the same as the waste heat utilization apparatus according to the first to ninth aspects. It is.

  Incidentally, the reference numerals in parentheses of each means described above are an example showing the correspondence with the specific means described in the embodiments described later.

(First embodiment)
In the present embodiment, the waste heat utilization apparatus 20 according to the present invention includes a travel electric motor 140, and a hybrid vehicle in which the engine (corresponding to the heat engine in the present invention) 10 is operated or stopped according to travel conditions. Is applied. The waste heat utilization apparatus 20 includes a Rankine cycle 30A that recovers energy from waste heat generated in the engine 10 based on the refrigeration cycle 20A. An expansion generator / electric compressor (hereinafter referred to as an expander / compressor) 110 as a fluid machine is provided in the compression section or expansion section of each cycle 20A, 30A, and a control device (corresponding to the control means of the present invention). ) 40 controls the operation of each cycle 20A, 30A and the expander / compressor 110. Hereinafter, the whole structure of the waste heat utilization apparatus 20 is demonstrated using FIG.

  First, the refrigeration cycle 20A moves the heat on the low temperature side to the high temperature side and uses the heat and heat for air conditioning. The expander / compressor 110, the condenser 21, the gas-liquid separator 22, the decompressor 23, The evaporator 24 and the like are connected in a ring shape.

  The expander / compressor 110 is a compression mode (acting as a compressor) that pressurizes and discharges the gas-phase refrigerant, and expansion that converts the fluid pressure during expansion of the superheated vapor refrigerant into kinetic energy and outputs mechanical energy. The mode (acting as an expander) is also combined. The expander / compressor 110 is connected to a generator / motor 120 having both functions as a generator and an electric motor. This is the power (when the expander / compressor 110 is operated in the compression mode). It operates as a power source that provides (rotational force) and operates as a generator that generates electric power with the power recovered by the expander / compressor (expander) 110 when operated in the expansion mode. The electric power generated by the generator / motor (generator) 120 is charged in the battery and used for starting the engine 10 and for normal operation of various electric loads (headlights, engine accessories, etc.) of the vehicle. It has become. Details of the expander / compressor 110 will be described later.

  The condenser 21 is provided on the refrigerant discharge side of the expander / compressor 110 (in the compression mode), cools the refrigerant compressed to high temperature and high pressure by outside air (air outside the passenger compartment) flowing into the heat exchange unit, It is a heat exchanger that condenses and liquefies. The gas-liquid separator 22 is a receiver that separates the refrigerant condensed by the condenser 21 into a gas-phase refrigerant and a liquid-phase refrigerant and causes the liquid-phase refrigerant to flow out. The decompressor 23 decompresses and expands the liquid-phase refrigerant separated by the gas-liquid separator 22. In this embodiment, the decompressor 23 decompresses the refrigerant in an enthalpy manner, and at the same time, expands and compresses the expander / compressor 110 in the compression mode. A temperature-type expansion valve that controls the throttle opening is employed so that the degree of superheat of the sucked refrigerant becomes a predetermined value.

  The evaporator 24 is a heat exchanger that exerts an endothermic effect by evaporating the refrigerant decompressed by the decompressor 23, and cools the conditioned air by this endothermic effect. A check valve 24 a that allows the refrigerant to flow only from the evaporator 24 side to the expander / compressor 110 side is provided on the refrigerant outflow side of the evaporator 24.

  The Rankine cycle 30A recovers energy (driving force in the expansion mode of the expander / compressor 110) from waste heat generated by the engine 10 that generates power for driving the vehicle. In the Rankine cycle 30A, the condenser 21 is shared with the refrigeration cycle 20A, and the gas-liquid separator 22 is connected between the expander / compressor 110 and the condenser 21 so as to bypass the condenser 21 ( The first bypass flow path 31 connected to the point A), and between the expander / compressor 110 and the check valve 24a (point B) to between the condenser 21 and the point A (point C). 2 bypass flow paths 32 are provided and formed as follows.

  That is, the first bypass flow path 31 is provided with a liquid pump 33 and a check valve 31a that allows the refrigerant to flow only from the gas-liquid separator 22 side to the liquid pump 33 side. . A heater 34 is provided between the point A and the expander / compressor 110. The heater 34 exchanges heat between the refrigerant (corresponding to the working fluid in the present invention) sent from the liquid pump 33 and the engine cooling water (corresponding to the waste heat fluid in the present invention) of the hot water circuit 10A in the engine 10. This is a heat exchanger that heats the refrigerant.

  A water pump (corresponding to the pump in the present invention) 12 is a pump that circulates engine cooling water in the hot water circuit 10A, and is a mechanical pump driven by the engine 10. The radiator 13 is a heat exchanger that cools the engine coolant by exchanging heat between the engine coolant and the outside air.

  A temperature sensor 14 for detecting the temperature of the engine coolant is provided on the outlet side of the hot water circuit 10A, and a temperature signal detected (output) by the temperature sensor 14 is input to a control device 40 described later. Further, the engine 10 is provided with a rotation speed sensor 15 (corresponding to the rotation speed detection means in the present invention) for detecting the rotation speed of the engine 10, and a rotation speed signal detected (output) by the rotation speed sensor 15. Is input to the control device 40 described later in the same manner as the temperature signal.

  The second bypass flow path 32 is provided with a check valve 32 a that allows the refrigerant to flow only from the expander / compressor 110 side to the refrigerant inlet side of the condenser 21. An on-off valve 35 is provided between the points A and C. The on-off valve 35 is an electromagnetic valve that opens and closes the refrigerant flow path, and is controlled by a control device 40 described later. Further, a control valve 36 is provided on the refrigerant discharge side when the expander / compressor 110 operates in the compression mode, and this is a discharge valve when the expander / compressor 110 is operated in the compression mode. That is, it functions as a check valve and is opened when operated in the expansion mode. The control valve 36 is controlled by a control device 40 described later.

  A Rankine cycle 30A is formed by the gas-liquid separator 22, the first bypass flow path 31, the liquid pump 33, the heater 34, the expander / compressor 110, the second bypass flow path 32, the condenser 21, and the like.

  Next, the schematic structure and operation of the expander / compressor 110 will be described. In this embodiment, the expander / compressor 110 is configured by a well-known vane type fluid machine, and FIG. 2 (a) shows a case where the expander / compressor 110 operates in the compression mode. b) shows the case of operating in the expansion mode.

  When operating the expander / compressor 110 in the compression mode, the control valve 36 is caused to function as a check valve, and the generator / motor 120 rotates the rotor 120a to suck and compress the refrigerant. The discharged high-pressure refrigerant is prevented from flowing back to the rotor 120 a side by the control valve 36.

  When the expander / compressor 110 is operated in the expansion mode, the rotor 120a is opened by opening the control valve 36 and introducing the superheated steam generated by the heater 34 into the expander / compressor 110 for expansion. To convert heat energy into mechanical energy. That is, the rotational driving force is generated according to the expansion mode of the expander / compressor 110.

  As shown in FIG. 1, the control device 40 includes an air conditioning request signal determined based on a set temperature set by the occupant, environmental conditions (outside air temperature, solar radiation amount), etc., a signal from the temperature sensor 14, and a rotation speed sensor 15. The liquid pump 33, the on-off valve 35, the expander / compressor 110, the control valve 36, the generator / motor 120, and the like are controlled based on these signals.

  Next, the operation (control by the control device 40) of the waste heat utilization apparatus 20 according to the above embodiment will be described using the flowchart shown in FIG.

  First, in step S110, it is determined whether or not there is an air conditioning request from a passenger. If it is determined that there is an air conditioning request, it is determined in step S120 based on the temperature signal from the temperature sensor 14 whether the temperature of the engine coolant is sufficient for heating in the heater 34.

  At this time, as shown in FIG. 4, when the engine coolant temperature rises from less than a predetermined temperature Tw2 to a predetermined temperature Tw2 or more, the engine coolant temperature becomes a temperature sufficient for heating (heatable temperature) (determination). It is determined as value 1). Further, when the engine coolant temperature falls below a predetermined temperature Tw1 lower than the predetermined temperature Tw2, it is determined that the engine coolant temperature is no longer a heatable temperature (determination value 0). As described above, in this embodiment, hysteresis is provided in the determination of the engine coolant temperature, and the predetermined temperature Tw1 and the predetermined temperature Tw2 are set to predetermined temperatures such that the temperature difference is 5 deg to 10 deg. The predetermined temperature Tw1 corresponds to the first predetermined temperature of the present invention, and the predetermined temperature Tw2 corresponds to the second predetermined temperature of the present invention.

  If it is determined in step S120 that the temperature is not heatable (determination value 0), normal air conditioning control is executed in step S130, and the refrigeration cycle 20A is continuously operated. Specifically, the liquid pump 33 is stopped, the open / close valve 35 is opened, and the generator / motor 120 is energized to rotate the rotor 120a with the control valve 36 functioning as a check valve. Thereby, as shown in FIG. 5, the refrigerant is expanded and compressor (compressor) 110 → heater 34 → condenser (radiator) 21 → gas-liquid separator 22 → decompressor 23 → evaporator (endothermic). ) Circulate in the order of 24 → expander / compressor (compressor) 110. The number of revolutions of the rotor 120a (the number of revolutions of the compressor) is the evaporator outlet target temperature calculated based on values such as the outside air temperature, the air conditioning set temperature, and the amount of solar radiation input from various sensors. (Corresponding to 1 cooling temperature) It is controlled based on TEO1. After the execution of step S130 is completed, the process returns to step S110 and the following steps are repeated.

  If it is determined in step S120 that the temperature can be heated (determination value 1), Rankine / air conditioning cooperative control (corresponding to the ON-OFF control in the present invention) is executed in step S140, and the Rankine cycle operation and the refrigeration cycle are performed. Control to switch operation appropriately. Details of Rankine / air-conditioning cooperative control will be described later. After the execution of step S140 is completed, the process returns to step S110 and the following steps are repeated.

  On the other hand, if it is determined in step S110 that there is no air conditioning request, in step S150, the temperature of the engine coolant is sufficient for heating in the heater 34 based on the temperature signal from the temperature sensor 14 as in step S120. Determine whether or not. If it is determined that the temperature is heatable (determination value 1), it is determined in step S160 whether or not the engine 10 is operating (operating state) based on the rotation speed signal from the rotation speed sensor 15. If it is determined that the engine is in operation, the water pump 12 is operated by the engine 10, and therefore the flow rate of the engine cooling water is sufficient for heating in the heater 34 (heatable flow rate) (engine cooling water). In step S170, the Rankine cycle 30A is operated.

  Specifically, the liquid pump 33 is operated with the on-off valve 35 closed and the control valve 36 opened. As a result, as shown in FIG. 6, the refrigerant is gas-liquid separator 22 → first bypass circuit 31 → liquid pump 33 → heater 34 → expander / compressor (expander) 110 → second bypass circuit 32 → It circulates in order of the condenser 21-> gas-liquid separator 22. Further, during the operation of the Rankine cycle 30A, the rotational speed of the generator / motor 120 is adjusted according to the engine coolant temperature so that the maximum generated power can be obtained by the generator / motor 120. After the execution of step S170 is completed, the process returns to step S110 and the following steps are repeated.

  If it is determined in step S150 that the temperature is not heatable (determination value 0), and if it is determined in step S160 that the engine is not operating (the engine cooling water is not in a flowing state), the liquid pump 33 is stopped in step S180. The energization of the generator / motor 120 is stopped, and the Rankine cycle 30A and the refrigeration cycle 20A are deactivated. After the execution of step S180 is completed, the process returns to step S110 and the following steps are repeated.

  Next, details of Rankine / air conditioning control executed in step S140 will be described with reference to the flowchart shown in FIG.

  First, in step S210, an evaporator outlet target temperature (corresponding to the second cooling temperature in the present invention) TEO2 used for Rankine / air conditioning cooperative control is calculated. Specifically, the same evaporator outlet target temperature (first cooling temperature) TEO1 used in normal air conditioning control (step S130 in FIG. 3) is first input from various sensors, etc. It calculates based on values, such as the amount of solar radiation, and calculates | requires a value lower than this by a predetermined value as an evaporator exit target temperature (2nd cooling temperature) TEO2. Specifically, the target temperature TEO2 is set to a temperature lower than the target temperature TEO1 by a predetermined value of 1 deg to 5 deg.

  Next, in step S220, it is determined whether or not the engine 10 is operating based on the rotational speed signal from the rotational speed sensor 15 as in step S160. If it is determined that the engine is operating, the flow rate of the engine cooling water is assumed to be a heatable flow rate (the engine cooling water is in a fluid state), and the waste heat from the engine 10 is sufficient for the operation of the Rankine cycle. Judge. Therefore, it is determined whether or not there is a request for operating the refrigeration cycle 20A in step S230 (details will be described later). If it is determined that there is no request for operating the refrigeration cycle (determination value 0), the control valve 36 is determined in step S240. Then, the Rankine cycle 30A is operated by controlling the on-off valve 35 and the liquid pump 33. After completion of execution of step S240, the process returns to the overall control routine.

  Whether or not the refrigeration cycle operation is necessary in step S230 is determined by comparing the evaporator outlet target temperature (second cooling temperature) TEO2 obtained in step S210 with the actual evaporator outlet temperature TE. Specifically, as shown in FIG. 8, a target temperature TEO3 that is higher than the evaporation outlet outlet target temperature TEO2 by a predetermined value is set, and when the actual temperature TE rises from less than the target temperature TEO3 to TEO3 or more, the refrigeration cycle is operated. It is determined that it is necessary (judgment value 1). Further, when the actual temperature TE falls below the target temperature TEO2, it is determined that the refrigeration cycle operation is no longer necessary (determination value 0). Thus, in the present embodiment, hysteresis is provided for determining whether or not the refrigeration cycle operation is necessary.

  On the other hand, if it is determined in step S220 that the engine 10 is not in operation, the rotational speed of the expander / compressor (compressor) 110 (rotational speed of the rotor 120a) is calculated based on the target temperature TEO2 in step S250. . In step S260, the generator / motor 120 is energized to rotate the rotor 120a at the rotational speed obtained in step S250, and the liquid pump 33, the on-off valve 35, and the control valve 36 are controlled to thereby control the refrigeration cycle 20A. Activate. After the completion of step S260, the process returns to the overall control routine.

  Thus, in Rankine / air conditioning cooperative control, when the refrigeration cycle 20A is operated, the evaporator outlet target temperature is set to a temperature TEO2 lower than the target temperature TEO1 that satisfies the required cooling capacity (used in normal air conditioning control), By increasing the discharge amount of the expander / compressor (compressor) 110 so as to exceed the required cooling capacity, the cooling capacity is not lowered compared to the normal air conditioning control, and even when the air conditioning is requested. A time during which the refrigeration cycle 20A can be deactivated is secured, and this is used for the operation of the Rankine cycle 30A.

  FIG. 9 shows an expander / compressor corresponding to a temporal change in engine speed for each of the normal air-conditioning control (step S130 in FIG. 3) and the Rankine / air-conditioning cooperative control (step S140 in FIG. 3). (Compressor) 110 shows a change in the number of rotations and switching between operation / non-operation of Rankine cycle 30A. As shown here, in the case of normal air-conditioning control, the expander / compressor (compressor) 110 is continuously operated, whereas in the case of Rankine / air-conditioning cooperative control, expansion is performed when the refrigeration cycle 20A is in operation. When the rotational speed of the machine / compressor (compressor) 110 is controlled to be higher and the operation of the refrigeration cycle 20A is stopped, the Rankine cycle 30A is operated.

  As described above, in the present embodiment, in the hybrid vehicle in which the engine 10 may be stopped even when the vehicle is in use, the temperature of the cooling water of the engine 10 is heated when determining whether the Rankine cycle 30A is operating or not. The flow rate of the engine cooling water is checked not only by determining whether or not the temperature is possible but also by determining whether or not the engine 10 is in operation. When the engine 10 is not in an operating state, the engine cooling water is in a flowing state. The Rankine cycle is not in operation. Therefore, the Rankine cycle can be reliably operated only when the waste heat from the engine 10 can be recovered, thereby efficiently recovering the waste heat and improving the fuel consumption rate of the vehicle. it can.

  Also, even when there is an air conditioning request, if the engine coolant temperature is a heatable temperature, the Rankine / air conditioning cooperative control ensures a time during which the refrigeration cycle 20A can be deactivated while the engine 10 is operating, During this time, the Rankine cycle 30A is operated. Thereby, waste heat recovery can be efficiently performed using the waste heat utilization apparatus 20.

(Second Embodiment)
A second embodiment of the present invention is shown in FIG. In the present embodiment, the first embodiment (FIG. 1) determines whether or not the flow rate of the engine coolant is sufficient based on the engine speed signal, whereas the flow rate sensor is connected to the hot water circuit 10A. (Corresponding to the flow rate detection means of the present invention) 41 is arranged, and the flow rate is directly detected by this. A flow signal from the flow sensor 41 is input to the control device 40. In the present embodiment, the water pump 12 for circulating the engine coolant in the hot water circuit 10A may be a mechanical pump driven by the engine 10 as in the first embodiment, or may be driven by an electric motor. It may be an electric pump.

  FIG. 11 is a flowchart showing the operation (control by the control device 40) of the waste heat utilization apparatus 20 according to the present embodiment. Steps S110 to S130, S150, S170, and S180 are the same as those in the first embodiment.

  In the first embodiment, the engine operation determination is performed based on the rotation speed signal in step S160 in FIG. 3, whereas in the present embodiment, the flow rate signal from the flow sensor 41 in step S165 in FIG. Based on the above, the flow rate determination of the engine cooling water is executed.

  Specifically, as shown in FIG. 12, when the flow rate of the engine cooling water detected by the flow rate sensor 41 becomes less than the predetermined flow rate Qw2 to be equal to or higher than the predetermined flow rate Qw2, the heating flow rate is reached (determination value 1). It is determined, and when the flow rate is less than the predetermined flow rate Qw1 less than the predetermined flow rate Qw2, it is determined that the flow rate is no longer heatable (determination value 0). Thus, in this embodiment, hysteresis is provided for determination of the engine coolant flow rate, and the flow rate difference between the predetermined flow rate Qw1 and the predetermined flow rate Qw2 is set to 2 L / min. The predetermined flow rate Qw1 corresponds to the first predetermined flow rate in the present invention, and the predetermined flow rate Qw2 corresponds to the second predetermined flow rate in the present invention.

  FIG. 13 shows details of Rankine / air-conditioning cooperative control executed in step S145 of FIG. Steps S210 and S230 to S260 are the same as those in the first embodiment. In step S225, the flow rate determination regarding the engine coolant is executed in the same manner as in step S165 of FIG.

  As described above, in the present embodiment, since the flow rate of the engine coolant is directly detected by the flow rate sensor 41 and the determination regarding the flow rate is performed based on this, whether or not the flow rate of the engine coolant is a heatable flow rate is determined. Can be determined more accurately, and the Rankine cycle can be operated for a longer time.

(Third embodiment)
A third embodiment of the present invention is shown in FIG. In each of the above-described embodiments (FIGS. 1 and 10), an integrated type (expander / compressor 110) constituted by one fluid machine 110 is used as an expander and a compressor. As such, the compressor 130 and the expander 131 may be independent from each other. The compressor 130 and the expander 131 are arranged in parallel, and on-off valves 38a and 38b, which are electromagnetic valves that open and close the passage to these, are further arranged. The control of the waste heat utilization device 20 by the control device 40 is performed in the same manner as in the first embodiment. However, when switching between the Rankine cycle 30A and the refrigeration cycle 20A, together with the liquid pump 33, the on-off valve 35, and the control valve 36 The on / off valves 38a and 38b are also controlled by the control device 40.

(Fourth embodiment)
A fourth embodiment of the present invention is shown in FIGS. In the fourth embodiment, an electric water pump 12a is used as the water pump for circulating the engine cooling water in the hot water circuit 10A with respect to the first embodiment (FIG. 1).

  The water pump 12a is a pump that uses an electric motor as a drive source, and is controlled by control means of the engine 10 (not shown). Therefore, unlike the mechanical water pump 12, the water pump 12a can operate independently of the engine 10 regardless of the operation stop of the engine 10. In the hybrid vehicle, the engine 10 may be stopped depending on the traveling conditions. In the mechanical water pump 12 according to the first embodiment, the water pump 12 is also stopped when the engine 10 is stopped. However, in the electric water pump 12a, even when the engine 10 is stopped, the water pump 12a can be operated to circulate the engine coolant in the hot water circuit 10A.

  An operation signal indicating the operating state of the water pump 12 a is input to the control device 40. When the water pump 12a is in an operating state, the control device 40 determines that the engine cooling water in the hot water circuit 10A is in a flowing state, and when the water pump 12a is in a non-operating state, the engine cooling water is in a flowing state. It is determined that there is no.

  The operation of the waste heat utilization apparatus 20 according to this embodiment (control by the control apparatus 40) will be described with reference to the flowcharts shown in FIGS. The flowcharts in FIGS. 16 and 17 are obtained by changing steps S160 and S220 of the flowcharts in FIGS. 3 and 7 described in the first embodiment to steps S166 and S226, respectively.

  If it is determined in step S110 that there is no air conditioning request and the engine coolant temperature is a heatable temperature in step S150, the control device 40 determines the operating state of the water pump 12a in step S166. When the water pump 12a is in an operating state, the engine coolant is in a fluid state, so that the refrigerant in the heater 34 can be heated, and the Rankine cycle 30A is operated in step S170.

  Further, when the water pump 12a is in a non-operating state, the engine cooling water is in a non-flowing state. Therefore, the refrigerant cannot be heated in the heater 34, and the Rankine cycle 30A is deactivated in step S180.

  On the other hand, if there is an air conditioning request in step S110 and it is determined in step S120 that the engine coolant temperature is a heatable temperature, control device 40 performs Rankine / air conditioning cooperative control in step S140. In Rankine / air conditioning cooperative control, after calculating the evaporator outlet target temperature TEO2 in step S210, the flow state of the engine coolant accompanying the operating state of the water pump 12a is determined in step S226 in the same manner as in step S166. Then, depending on the determination in step S266, the operation of the Rankine cycle 30A and the refrigeration cycle 20A is selectively used in steps S240 and S260.

  As described above, in the present embodiment, by using the water pump 12a as an electric pump, it is possible to reliably grasp the flow state of the engine coolant from the operating state of the water pump 12a. Therefore, the same effect as the first embodiment can be obtained.

  In the determination of the flow state of the engine cooling water, it may be determined that the water pump 12a is in a flowing state when the rotational speed of the water pump 12a is equal to or higher than a predetermined rotational speed and is not in a flowing state when the rotational speed is less than the predetermined rotational speed.

(Fifth embodiment)
A fifth embodiment of the present invention is shown in FIG. In the fifth embodiment, the refrigeration cycle 20A is eliminated from the fourth embodiment.

  The waste heat utilization apparatus 20 is mainly formed of a Rankine cycle 30A. Since the refrigeration cycle 20A is abolished with respect to the fourth embodiment (FIG. 15), the input of the air conditioning request signal to the control device 40 is abolished. Further, the expander / compressor 110 is changed to a dedicated expander 131, and the check valves 31a and 32a, the on-off valve 35, and the control valve 36 are eliminated. The expander 131, the condenser 21, the gas-liquid separator 22, the liquid pump 33, and the heater 34 are sequentially connected in an annular manner to form the Rankine cycle 30A.

  The control device 40 controls the operation of the Rankine cycle 30A using steps S150, S166, S170, and S180 in the flowchart described in FIG. The Rankine cycle 30A is operated according to the engine coolant temperature and the flow state of the engine coolant, so that efficient waste heat recovery is possible.

(Sixth embodiment)
A sixth embodiment of the present invention is shown in FIGS. 6th Embodiment adds the refrigerating cycle 20B provided with the compressor 130 while sharing the condenser 21 with respect to the said 5th Embodiment (FIG. 18).

  The refrigeration cycle 20B is formed as follows by using the branch flow path 25 provided in the Rankine cycle 30B. That is, the branch flow path 25 is formed as a flow path branched from the outflow side of the gas-liquid separator 22 and connected between the expander 131 and the condenser 21 (point D). In the branch flow path 25, a decompressor 23, an evaporator 24, and a compressor 130 are disposed. Therefore, by sharing the condenser 21 and the gas-liquid separator 22 of the Rankine cycle 30A, the compressor 130, the condenser 21, the gas-liquid separator 22, the decompressor 23, and the evaporator 24 are sequentially connected in an annular shape. A refrigeration cycle 20B is formed.

  Since the refrigeration cycle 20B includes a dedicated compressor 130, the refrigeration cycle 20B can operate independently of the Rankine cycle 30A. That is, in the present waste heat utilization apparatus 20, the Rankine cycle 30A can be operated independently, the refrigeration cycle 20B can be operated independently, and the Rankine cycle 30A and the refrigeration cycle 20B can be operated simultaneously.

  Hereinafter, the operation of the waste heat utilization apparatus 20 according to the embodiment (control by the control apparatus 40) will be described with reference to the flowchart shown in FIG. In the flowchart shown in FIG. 20, step S121 is added to the flowchart described in FIG. 16 of the fourth embodiment, and steps S130, S140, S170, and S180 are changed to steps S131, S141, S171, and S181, respectively. Is.

  First, in step S110, it is determined whether or not there is an air conditioning request from a passenger. If it is determined that there is no air conditioning request, it is determined in step S150 based on the temperature signal from the temperature sensor 14 whether the temperature of the engine coolant is sufficient for heating in the heater 34.

  If it is determined in step S150 that the temperature is heatable (determination value 1), the flow state of the engine cooling water is determined from the operating state of the water pump 12a in step S166. If it is determined in step S166 that the engine coolant is in a fluid state with the operation of the water pump 12a, Rankine single operation (Rankine single control) is executed in Step S171 to operate the Rankine cycle 30A (the refrigeration cycle 20B is not operating). Status).

  If it is determined in step S150 that the temperature is not heatable (decision value 0), and it is determined in step S166 that the water pump 12a is not operating and the engine coolant is not in a fluid state, Rankine / air conditioning is performed in step S181. A non-operation is performed, and both Rankine cycle 30A and refrigeration cycle 20B are made non-operational.

  On the other hand, if it is determined in step S110 that there is an air conditioning request from the occupant, it is determined in step S120 whether the temperature of the engine coolant is sufficient for heating in the heater 34.

  If it is determined in step S120 that the temperature is not heatable (decision value 0), the air conditioning single operation (air conditioning normal control) is executed in step S131, and the refrigeration cycle 20B is operated (the Rankine cycle 30A is in a non-operating state).

  However, if it is determined in step S120 that the temperature is heatable (determination value 1), the flow state of the engine cooling water is determined from the operating state of the water pump 12a in step S121. If it is determined that the engine cooling water is not in the fluid state, the process proceeds to step S131, and the air conditioning single operation is executed. If it is determined that the engine cooling water is in the fluid state, the Rankine / air conditioning simultaneous operation (simultaneous operation control) is performed in step S141. ) And the operation of the Rankine cycle 30A and the operation of the refrigeration cycle 20B are performed simultaneously.

  In the Rankine / air conditioning simultaneous operation, the control device 40 adjusts the rotation speed of the expander 130 of the Rankine cycle 30A so as not to exceed the heat dissipation capacity in the condenser 21.

  That is, the control device 40 has the heat radiation capacity in the condenser 21 according to the temperature of the outside air flowing into the heat exchange part of the condenser 21, the flow rate of the outside air, and the size of the condenser 21 itself in FIG. Determine as shown by the broken line.

  Further, during the operation of the refrigeration cycle 20B, the amount of heat absorbed by the refrigerant 24 in the evaporator 24 and the compression work by the compressor 130 are received in order to exhibit the cooling capacity required for air conditioning (FIG. 21B). The controller 21 needs to release heat corresponding to the amount of heat, and the controller 40 uses this as the refrigeration cycle heat release amount (corresponding to the first heat release amount in the present invention) shown in the lower region of FIG. decide.

  When the Rankine cycle 30A is in operation, the condenser 21 needs to release heat for cooling and condensing the refrigerant flowing out of the expander 131, and the control device 40 determines the amount of heat released at this time as shown in FIG. It is determined as the Rankine cycle heat release amount (corresponding to the second heat release amount in the present invention) shown in the upper region of a). The Rankine cycle heat release amount is proportional to the flow rate of the refrigerant flowing through the condenser 21, that is, proportional to the rotational speed of the expander 131, as shown in FIG.

  Therefore, when the Rankine / air conditioning simultaneous operation is executed, the control device 40 controls the rotation speed of the expander 131 so that the sum of the air conditioner cycle heat dissipation amount and the Rankine cycle heat dissipation amount is less than the condenser heat dissipation capability. To do. That is, if the required cooling capacity in the refrigeration cycle 20B is low, the rotational speed of the expander 131 is increased to increase the recovery driving force (power generation amount) in the Rankine cycle 30A. Conversely, if the required cooling capacity in the refrigeration cycle 20B is high, the rotational speed of the expander 131 is lowered to reduce the recovery driving force (power generation amount) in the Rankine cycle 30A.

  As described above, in the present embodiment, the condenser 21 is shared with the Rankine cycle 30A and the refrigeration cycle 20B having the dedicated compressor 130 is provided. The Rankine / air conditioning simultaneous operation can be executed. When the Rankine cycle 30A is operated, since it corresponds to the engine coolant temperature and the flow state of the engine coolant, efficient waste heat recovery can be performed.

  When the Rankine / air conditioning simultaneous operation is executed, the rotational speed of the expander 131 is adjusted so that the sum of the refrigeration cycle heat release amount and the Rankine cycle heat release amount is less than the condenser heat release capability. Thus, the required cooling capacity in the refrigeration cycle 20B can be ensured and waste heat can be recovered without waste in the Rankine cycle 30A without causing the heat radiation function 21 to fail.

(Seventh embodiment)
A seventh embodiment of the present invention is shown in FIG. In the seventh embodiment, the electric water pump 12a is changed to a mechanical water pump 12 with respect to the sixth embodiment (FIG. 20), and a rotation speed sensor 15 is added to the engine 10. The water pump 12 and the rotation speed sensor 15 are the same as those described in the first embodiment (FIG. 1).

  In the present embodiment, the determination of the engine cooling water flow state in steps S121 and S166 in FIG. 20 described in the sixth embodiment is performed based on the operating state determination of the engine 10 obtained from the rotation speed signal of the rotation speed sensor 15. By replacing with, the same effect as in the sixth embodiment can be obtained.

(Eighth embodiment)
FIG. 23 shows an eighth embodiment of the present invention. In the eighth embodiment, the refrigeration cycle 20B is eliminated from the seventh embodiment (FIG. 22). Moreover, this embodiment is equivalent to what changed the electric water pump 12a into the mechanical water pump 12 with respect to 5th Embodiment (FIG. 18).

  The Rankine cycle 30A is operated by the control device 40 according to the engine coolant temperature obtained from the temperature sensor 14 and the operating state (flow state of the engine coolant) of the engine 10 obtained from the rotational speed sensor 15. Waste heat recovery becomes possible.

(Other embodiments)
In the first, third, seventh, and eighth embodiments, the operating state of the engine 10 is grasped by the engine speed obtained by the speed sensor 15, but instead of this, the intake of the engine 10 is absorbed. The atmospheric pressure, the intake throttle valve opening, etc. may be used.

  In the second embodiment, the flow sensor 41 is disposed between the engine 10 and the heater 34. Instead, the flow sensor 41 is disposed in the vicinity of the outlet side of the engine coolant of the heater 34. As a result, the influence of the response time delay of the flow sensor 41 can be eliminated, and the reliable flow state of the waste heat fluid in the heater 34 can be detected.

  In each of the above embodiments, the cooling water of the engine 10 is used as the waste heat fluid of the heat engine, but instead, exhaust gas may be used.

  Further, in each of the above embodiments, the Rankine cycle 30A and the waste heat utilization device 20 of the present invention are applied to a hybrid vehicle. However, the Rankine cycle 30A and the waste heat utilization device 20 are also applied to an idle stop vehicle in which the engine 10 is operated and stopped according to a traveling condition. Also good. Further, the present invention can be applied to a normal vehicle on which the engine 10 is mounted.

It is a schematic diagram which shows the whole structure of the waste-heat utilization apparatus in 1st Embodiment. It is sectional drawing which shows the expander and compressor in 1st Embodiment. It is a flowchart used for the whole control by a control device in a 1st embodiment. It is a figure explaining the cooling water temperature determination by the control apparatus in 1st Embodiment. It is a schematic diagram which shows the refrigerating cycle operation state of the waste heat utilization apparatus in 1st Embodiment. It is a schematic diagram which shows the Rankine cycle operation state of the waste heat utilization apparatus in 1st Embodiment. It is a flowchart used for Rankine / air-conditioning cooperative control by a control device in a 1st embodiment. It is a figure explaining the refrigerating cycle operation necessity determination by the control apparatus in 1st Embodiment. It is a figure which contrasts and demonstrates normal air-conditioning control and Rankine / air-conditioning cooperation control by the control apparatus in 1st Embodiment. It is a schematic diagram which shows the whole structure of the waste-heat utilization apparatus in 2nd Embodiment. It is a flowchart used for the whole control by a control apparatus in 2nd Embodiment. It is a figure explaining the cooling water flow rate determination by the control apparatus in 2nd Embodiment. It is a flowchart used for Rankine / air-conditioning cooperative control by a control apparatus in 2nd Embodiment. It is a schematic diagram which shows the whole structure of the waste-heat utilization apparatus in 3rd Embodiment. It is a schematic diagram which shows the whole structure of the waste-heat utilization apparatus in 4th Embodiment. It is a flowchart used for the whole control by a control apparatus in 4th Embodiment. It is a flowchart used for Rankine / air-conditioning cooperative control by a control apparatus in 4th Embodiment. It is a schematic diagram which shows the whole structure of the waste-heat utilization apparatus in 5th Embodiment. It is a schematic diagram which shows the whole structure of the waste-heat utilization apparatus in 6th Embodiment. It is a flowchart used for the whole control by a control apparatus in 6th Embodiment. It is a time chart which shows the amount of heat radiation of a condenser, demand cooling capacity, and expansion machine rotation speed in a 6th embodiment. It is a schematic diagram which shows the whole structure of the waste-heat utilization apparatus in 7th Embodiment. It is a schematic diagram which shows the whole structure of the waste-heat utilization apparatus in 8th Embodiment.

Explanation of symbols

10 Engine (heat engine)
12 Water pump (mechanical pump)
12a Water pump (electric pump)
14 Temperature sensor 15 Rotational speed sensor (Rotational speed detection means)
20 Waste heat utilization device 20A, 20B Refrigeration cycle 21 Condenser 24 Evaporator 30A Rankine cycle 34 Heater 40 Control device (control means)
41 Flow rate sensor (flow rate detection means)
110 Expansion generator and electric compressor (compressor, expander)
130 Compressor 131 Expander

Claims (18)

The working fluid in the cycle is heated by the heater (34) by the waste heat fluid accompanying the waste heat of the heat engine (10), and the heated working fluid is expanded by the expander (110) to obtain mechanical energy. A Rankine cycle (30A) for condensing and liquefying the expanded working fluid with a condenser (21),
Control means (40) for controlling the operation of the Rankine cycle (30A) ;
A rotational speed detection means (15) for detecting the rotational speed of the heat engine (10);
The compressor (110, 130), which is also used as the expander (110) or arranged in parallel to the expander (110), is formed by sharing the condenser (21), and the control A waste heat utilization apparatus having a refrigeration cycle (20A), the operation of which is controlled by means (40) ,
The control means (40) grasps the operating state of the heat engine (10) based on the rotational speed obtained from the rotational speed detection means (15), and determines the waste heat fluid according to the operating state of the heat engine (10). The flow state is grasped, and when the temperature of the waste heat fluid is equal to or higher than a predetermined temperature (Tw1, Tw2) and the waste heat fluid is in a flow state, the Rankine cycle (30A) is operated and the refrigeration is performed. When the operation of the cycle (20A) is necessary, if the temperature of the waste heat fluid is equal to or higher than the predetermined temperature (Tw1, Tw2), the compressor (110, 130) is controlled to be turned on and off, The waste heat utilization apparatus , wherein the Rankine cycle (30A) is operated when the compressor (110, 130) is OFF . The control means (40) controls the compressor (110, 130) so that the cooling capacity of the refrigeration cycle (20A) exceeds a required cooling capacity when the compressor (110, 130) is turned on. The waste heat utilization apparatus according to claim 1 , wherein the discharge amount is increased. The control means (40) includes a first cooling temperature (TEO1) in which the temperature of the working fluid in the evaporator (24) of the refrigeration cycle (20A) or the temperature of another part related thereto satisfies the required cooling capacity. 3. The waste heat utilization apparatus according to claim 2 , wherein the discharge amount of the compressor (110, 130) is increased so that the second cooling temperature (TEO 2) is lower than the second cooling temperature (TEO 2). The working fluid in the cycle is heated by the heater (34) by the waste heat fluid accompanying the waste heat of the heat engine (10), and the heated working fluid is expanded by the expander (110) to obtain mechanical energy. A Rankine cycle (30A) for condensing and liquefying the expanded working fluid with a condenser (21),
Control means (40) for controlling the operation of the Rankine cycle (30A) ;
A rotational speed detection means (15) for detecting the rotational speed of the heat engine (10);
A refrigeration system including a dedicated compressor (130), which is formed by sharing the condenser (21), and whose operation can be independently controlled with respect to the Rankine cycle (30A) by the control means (40). A waste heat utilization device having a cycle (20B) ,
The control means (40) grasps the operating state of the heat engine (10) based on the rotational speed obtained from the rotational speed detection means (15), and determines the waste heat fluid according to the operating state of the heat engine (10). The flow state is grasped, and when the temperature of the waste heat fluid is equal to or higher than a predetermined temperature (Tw1, Tw2) and the waste heat fluid is in a flow state, the Rankine cycle (30A) is operated and the refrigeration is performed. When the operation of the cycle (20B) is necessary, if the temperature of the waste heat fluid is equal to or higher than the predetermined temperature (Tw1, Tw2) and the waste heat fluid is in a fluid state, the refrigeration cycle (20B) A waste heat utilization apparatus that operates the Rankine cycle (30A) simultaneously . The control means (40) includes a first heat radiation amount required for condensing the working fluid discharged from the compressor (130) and a second heat amount required for condensing the working fluid discharged from the expander (110). The waste according to claim 4 , wherein the operating rotational speed of the expander (110) is controlled so that a sum of the heat dissipation amount is equal to or less than a heat dissipation capability during condensation in the condenser (21). Heat utilization device. The predetermined temperature (Tw1, Tw2) has a first predetermined temperature (Tw1), by it is greater than the second predetermined temperature (Tw2), claims 1 to, characterized in that set to have a hysteresis Item 6. The waste heat utilization apparatus according to any one of Items 5 . The waste heat fluid is cooling water that cools the heat engine (10),
The cooling water, any one of claims 1 to 6, characterized in that it is circulated to the heater (34) by a mechanical pump (12) driven by the heat engine (10) The waste heat utilization device described in 1. The waste heat utilization apparatus according to any one of claims 1 to 7 , wherein the heat engine (10) is an internal combustion engine (10) for a vehicle. The waste heat utilization apparatus according to claim 8 , wherein the vehicle is a hybrid vehicle in which the internal combustion engine (10) is operated or stopped according to a traveling condition, or an idle stop vehicle. The working fluid in the cycle is heated by the heater (34) by the waste heat fluid accompanying the waste heat of the heat engine (10), and the heated working fluid is expanded by the expander (110) to obtain mechanical energy. A waste heat utilization apparatus having a Rankine cycle (30A) for condensing and liquefying the expanded working fluid with a condenser (21),
A refrigeration cycle (20A) that includes a compressor (110, 130) that is also used as the expander (110) or is arranged in parallel to the expander (110), and is formed by sharing the condenser (21). )
The operating state of the heat engine (10) is determined from the rotational speed of the heat engine (10), the flow state of the waste heat fluid is determined from the operating state of the heat engine (10), and the temperature of the waste heat fluid is determined. When the temperature is equal to or higher than a predetermined temperature (Tw1, Tw2) and the waste heat fluid is in a fluid state, the Rankine cycle (30A) is operated and the refrigeration cycle (20A) is required to be operated. When the temperature of the waste heat fluid is equal to or higher than the predetermined temperature (Tw1, Tw2), the compressor (110, 130) is controlled to be turned on and off, and when the compressor (110, 130) is turned off, A control method for a waste heat utilization apparatus, characterized by operating a Rankine cycle (30A) . When the compressor (110, 130) is turned on, the discharge amount of the compressor (110, 130) is increased so that the cooling capacity of the refrigeration cycle (20A) is equal to or higher than the required cooling capacity. The method for controlling a waste heat recovery apparatus according to claim 10 . The second cooling temperature in which the temperature of the working fluid in the evaporator (24) of the refrigeration cycle (20A) or the temperature of other parts related thereto is lower than the first cooling temperature (TEO1) that satisfies the required cooling capacity. The method for controlling a waste heat recovery apparatus according to claim 11 , wherein the discharge amount of the compressor (110, 130) is increased so as to be (TEO2). The working fluid in the cycle is heated by the heater (34) by the waste heat fluid accompanying the waste heat of the heat engine (10), and the heated working fluid is expanded by the expander (110) to obtain mechanical energy. A waste heat utilization apparatus having a Rankine cycle (30A) for condensing and liquefying the expanded working fluid with a condenser (21),
A refrigeration cycle (20B) that includes a dedicated compressor (130), is formed by sharing the condenser (21), and that can be operated and controlled independently of the Rankine cycle (30A). ,
The operating state of the heat engine (10) is determined from the rotational speed of the heat engine (10), the flow state of the waste heat fluid is determined from the operating state of the heat engine (10), and the temperature of the waste heat fluid is determined. When the temperature is equal to or higher than a predetermined temperature (Tw1, Tw2) and the waste heat fluid is in a flow state, the Rankine cycle (30A) is operated and the refrigeration cycle (20B) is required to be operated. When the temperature of the waste heat fluid is equal to or higher than the predetermined temperature (Tw1, Tw2) and the waste heat fluid is in a flowing state, the refrigeration cycle (20A) and the Rankine cycle (30A) are operated simultaneously. A method for controlling a waste heat utilization apparatus. The sum of the first heat release amount required for the condensation of the working fluid discharged from the compressor (130) and the second heat release amount required for the condensation of the working fluid discharged from the expander (110) is The method for controlling a waste heat utilization apparatus according to claim 13 , wherein the operating rotational speed of the expander (110) is controlled so as to be equal to or less than a heat dissipation capacity during condensation in the condenser (21). The predetermined temperature (Tw1, Tw2) is claim 10 to 14 in which the first predetermined temperature (Tw1), by it is greater than the second predetermined temperature (Tw2), wherein the set to have a hysteresis The control method of the waste heat utilization apparatus as described in any one of these . The waste heat fluid is cooling water that cools the heat engine (10),
The cooling water, any one of claims 10 to claim 15, characterized in that it is circulated to the heater (34) by a mechanical pump that is driven by the heat engine (10) (12) Control method of waste heat utilization apparatus as described in 1. The method for controlling a waste heat utilization apparatus according to any one of claims 10 to 16 , wherein the heat engine (10) is an internal combustion engine (10) for a vehicle. The method for controlling a waste heat utilization apparatus according to claim 17 , wherein the vehicle is a hybrid vehicle in which the internal combustion engine (10) is activated or stopped according to a traveling condition, or an idle stop vehicle.

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