JP4699972B2 - Waste heat utilization apparatus and control method thereof - Google Patents

Description

  The present invention relates to a waste heat utilization apparatus that recovers power using waste heat of a heat-generating device and a control method thereof, and is suitable for use in, for example, a vehicle equipped with an internal combustion engine.

  As a conventional waste heat utilization apparatus, for example, one disclosed in Patent Document 1 is known. That is, this waste heat utilization apparatus has a refrigeration cycle for air conditioning and a Rankine cycle that utilizes cooling waste heat of an internal combustion engine as a heat generating device. A compressor that is driven by the power of the internal combustion engine to compress and discharge the refrigerant is provided in the refrigeration cycle, and an expander that is operated by the expansion of the refrigerant heated by the cooling waste heat is independently provided in the Rankine cycle. It is installed. The Rankine cycle is configured by sharing a condenser (heat radiator) in the refrigeration cycle.

In this waste heat utilization device, the refrigeration cycle, the Rankine cycle can be operated independently, or the refrigeration cycle and the Rankine cycle can be operated simultaneously, depending on the necessity of air conditioning and whether or not the cooling waste heat can be recovered.
JP 2005-307951 A

  However, when the refrigeration cycle and the Rankine cycle are operated simultaneously in the above waste heat utilization device and the cooling load on the refrigeration cycle side is large (for example, when the outside air temperature is high) such as in summer, the waste heat cooled by the Rankine cycle is used. Despite the recovery of wastewater, it was found that the entire waste heat utilization device returned and lost energy. Hereinafter, this problem will be described in detail.

  First, consider the case where the refrigeration cycle is operating alone. The power of the compressor with respect to the cooling load of the refrigeration cycle can be expressed as shown in FIG. Further, the operating state of the refrigeration cycle can be represented by a Mollier diagram (Ph diagram) as shown in FIG.

  Next, consider the case where the refrigeration cycle and Rankine cycle are operated simultaneously. Similarly to the above, the power of the compressor is as shown in FIG. 17, and the compressor power is much higher during the simultaneous operation (broken line in FIG. 17) than during the single operation (solid line in FIG. 17). . The reason for this is that both the heat from the refrigeration cycle and the heat from the Rankine cycle flow into the condenser, so the condensation pressure of the condenser during simultaneous operation is compared to that during single operation. Because it becomes high. That is, as shown in the Mollier diagram of FIG. 18, as the condensation pressure in the condenser increases, the compression ratio (= discharge pressure / suction pressure) of the compressor increases correspondingly, and the power deteriorates (power increases). End up.

  About the said content, the environmental conditions in the operation | movement of a waste-heat utilization apparatus are made into external temperature, and it supplementarily demonstrates the relationship between the thermal radiation state in a condenser, and the power deterioration in a compressor using FIG. In FIG. 19, the necessary heat radiation amount with respect to the outside air temperature in the condenser when the refrigerant flow rate necessary for cooling is supplied is represented as the air conditioner heat radiation amount. Further, the heat radiation amount with respect to the outside air temperature when the maximum flow rate of the condenser (the flow rate at which the predetermined pressure loss is caused) flows is expressed as the heat radiation capability. Here, if the required heat dissipation amount for the outside air temperature during Rankine cycle operation is the Rankine heat dissipation amount, the sum of the air conditioner heat dissipation amount and the Rankine heat dissipation amount, that is, the required heat dissipation amount in the condenser during simultaneous operation is high The degree of increase increases as time goes on, and if it exceeds a certain outside temperature, it will exceed the heat dissipation capacity. Therefore, the higher the outside air temperature, the larger the increase in the refrigerant flow rate in the condenser and the higher the pressure loss. If the pressure loss in the condenser increases, the high pressure of the compressor rises and the power consumption increases.

  Here, when the energy balance of the waste heat utilization apparatus with respect to the outside air temperature is considered, it is as shown in FIG. That is, since the cooling load increases as the outside air temperature rises, as described above, the power increase of the compressor deteriorates (solid line in FIG. 20). Further, when the outside air temperature rises in the Rankine cycle, as described above, the heat radiation in the condenser becomes severe, the pressure difference (expansion pressure ratio) before and after the expander decreases, and the recovered energy decreases (in FIG. 20). dotted line). These two characteristic lines intersect at a certain outside temperature. This point is the point where the energy balance of the waste heat utilization device becomes zero. In other words, at this point, even if energy is recovered in the Rankine cycle, this recovered energy is offset by an increase in power energy of the refrigeration cycle (compressor). In other words, the Rankine cycle functions effectively at an outside temperature below this point, but if the Rankine cycle is operated at an outside temperature above this point, the energy balance will be negative and the fuel efficiency of the internal combustion engine will deteriorate. I will let you.

  In view of the above problems, an object of the present invention is to provide a waste heat utilization device capable of preventing an increase in power of a compressor due to Rankine cycle operation and improving an energy balance during simultaneous operation of a refrigeration cycle and a Rankine cycle, and its It is to provide a control method.

  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 refrigeration includes the compressor (210) that compresses the low-pressure refrigerant sucked from the evaporator (250) side that cools the conditioned air into high-temperature and high-pressure and discharges the refrigerant to the condenser (220) side. The cycle (200) and the condenser (220) are shared, and mechanical energy is supplied to the expander (320) by expansion of the refrigerant pumped by the pump (330) and heated by the waste heat of the heat generating device (10). In the waste heat utilization apparatus having the Rankine cycle (300) to be recovered and the control means (500) for controlling the operation of the refrigeration cycle (200) and the Rankine cycle (300), the control means (500) includes the refrigeration cycle (200). ) Continuous control for continuously operating the Rankine cycle (300) regardless of the operating state of the compressor (210) when the load is lower than the predetermined load. And it executes, if the high-load state where the load of the refrigeration cycle (200) is higher than the predetermined load, is characterized by performing the intermittent operation intermittently controlling the Rankine cycle (300).

  As a result, when the load of the refrigeration cycle (200) is lower than the predetermined load, the mechanical energy recovered in the Rankine cycle (300) exceeds the energy for driving the compressor (210), so the energy balance is increased. By operating the Rankine cycle (300) continuously, the waste heat of the heat generating device (10) can be effectively utilized.

  Further, when the load of the refrigeration cycle (200) is in a high load state, the intermittent control of the Rankine cycle (300) is performed to prevent an increase in power of the compressor (210) and improve the energy balance. Can do.

  According to the second aspect of the present invention, the increase in the driving energy of the compressor (210) due to the simultaneous operation of the compressor (210) and the expander (320) corresponds to the high load state. By setting the state as exceeding the mechanical energy recovered in (320), it is possible to clarify the criteria for making the energy balance positive.

  In the invention according to claim 3, the control means (500) intermittently operates the compressor (210) when executing the intermittent control, and the Rankine cycle (300) so as to be reverse to the intermittent operation. It is characterized by driving intermittently.

  Accordingly, when performing the intermittent control, the Rankine cycle (300) is operated when the compressor (210) is stopped, that is, when the energy for driving the compressor (210) is not used. Since the mechanical energy according to (320) is recovered, the energy balance can be positively ensured.

  As in the invention described in claim 4, the compressor (210) is a fixed capacity compressor (210) that is driven by the drive source (10) and has a predetermined amount of discharge capacity per revolution, The control means (500) can perform intermittent operation of the compressor (210) if the clutch (212) is connected to or disconnected from the drive source (10) or the drive source (10) is turned on and off. It becomes possible.

  Further, as in the fifth aspect of the invention, the compressor (210) is a variable capacity compressor (210) capable of adjusting a discharge capacity per one rotation, and the control means (500) includes the first If the discharge capacity is switched to the second discharge capacity larger than the first discharge capacity, the intermittent operation of the compressor (210) can be performed.

  The invention according to claim 6 further includes opening / closing means (322) for opening / closing a refrigerant flow path of the refrigerant circulating in the Rankine cycle (300), and the control means (500) performs the Rankine cycle when performing intermittent control. When stopping (300), the opening / closing means (322) is closed.

  Thereby, since circulation of a refrigerant can be stopped, a Rankine cycle (300) can be stopped immediately.

  The invention according to claim 7 is characterized in that the control means (500) stops the pump (330) after closing the opening / closing means (322).

  Thereby, pumping of a refrigerant | coolant can be stopped and a Rankine cycle (300) can be stopped reliably.

  The invention according to claim 8 is characterized in that the opening / closing means (322) is provided on the refrigerant inflow side of the expander (320).

  Thereby, since the inflow of the refrigerant | coolant with respect to an expander (320) can be stopped and expansion | swelling of a refrigerant | coolant can be stopped, a Rankine cycle (300) can be stopped immediately and effectively.

  In invention of Claim 9, it has a bypass passage (323) which bypasses an expander (320), and bypass opening-and-closing means (324) which opens and closes a bypass passage (323), and control means (500) includes In performing the intermittent control, when the Rankine cycle (300) is stopped, the bypass opening / closing means (324) is opened.

  Thereby, the high pressure side and the low pressure side of the expander (320) can be equalized, and the expander (320) can be easily stopped, so that the Rankine cycle (300) can be stopped safely and reliably. it can.

  The invention according to claim 10 includes a generator (321A) which is connected to the expander (320) and is driven by mechanical energy to generate electric power, and the control means (500) includes the bypass opening / closing means (324). ), The generator (321A) is stopped.

  In the expander (320), if the generator (321A) is stopped before the bypass opening / closing means (324) is opened, the expander (320) having a lighter load operates on the high rotation side at once due to the expansion of the refrigerant. Will be stopped. Therefore, after equalizing the high-pressure side and the low-pressure side of the Rankine cycle (300), the generator (321A) is stopped to prevent the above-mentioned high-rotation operation, and the expander (320) can be safely and reliably. Can be stopped.

  The invention according to claim 11 is characterized in that the control means (500) grasps the load of the refrigeration cycle (200) from the outside air temperature.

  The outside air temperature correlates with the load of the refrigeration cycle (200), whereby the load of the refrigeration cycle (200) can be easily grasped without using complicated detection means and detection methods.

  In the invention according to claim 12, the control means (500) combines the load of the refrigeration cycle (200) from information for controlling the heat generating device (10) and information for controlling the refrigeration cycle (200). It is characterized by grasping.

  As a result, the condition for executing the intermittent control can be grasped in more detail and accurately, so that the accuracy of the energy balance plus can be improved.

  As in the invention described in claim 13, the heat generating device (10) is an internal combustion engine (10) for a vehicle, and information for controlling the heat generating device (10) includes the speed of the vehicle, the internal combustion engine (10). At least one of the number of rotations, the outside air temperature, and the cooling medium temperature of the internal combustion engine (10) can be employed.

  Further, as in the invention described in claim 14, the information for controlling the refrigeration cycle (200) includes the room temperature, the target room temperature, the temperature of the conditioned air cooled by the evaporator (250), and the refrigeration cycle (200). At least one of the internal refrigerant pressures can be employed.

  In the invention according to claim 15, the control means (500) causes the high load state to be a high pressure side which is a high pressure side of the expander (320) with respect to a low pressure side pressure (PL) which is a low pressure side of the expander (320). It is characterized by grasping by the expansion pressure ratio (PH / PL) indicated by the ratio of pressure (PH).

  Thereby, a high load state can be easily grasped without using complicated detection means and detection methods.

  The expansion pressure ratio (P1 / P2) is equal to the waste heat temperature of the heat generating device (10) and the refrigerant in the condenser (220) on the downstream side of the expander (320), as in the invention described in claim 16. , The temperature of the outside air in the condenser (220), and the speed of the outside air.

  The invention described in claims 17 to 32 relates to a control method in the waste heat utilization apparatus (100), and its technical significance is essentially the same as that of the waste heat utilization apparatus according to claims 1 to 16. Are the same.

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

(First embodiment)
A first embodiment of the present invention is shown in FIGS. 1 to 5, and a specific configuration will be described first. The waste heat utilization apparatus 100 of the present invention is applied to a general passenger car (vehicle) using the engine 10 as a driving source for travel. The refrigeration cycle 200 and some devices (condenser) in the refrigeration cycle 200 are used. 220, the gas-liquid separator 230, the supercooler 231) and the Rankine cycle 300 including the generator 321, and the controller 500 (500 a to 500 d) for controlling the operation of the refrigeration cycle 200 and the Rankine cycle 300. is doing.

  As shown in FIG. 1, the engine 10 is a water-cooled internal combustion engine (corresponding to the heat generating device in the present invention), a radiator circuit 20 that cools the engine 10 by circulation of engine cooling water (hereinafter referred to as cooling water), and It has a heater circuit 30 that heats conditioned air using cooling water (hot water) as a heat source. The engine 10 is provided with an alternator 11 that is driven by the driving force of the engine 10 transmitted through the belt 12 to generate electric power. The electric power generated by the alternator 11 is charged in the battery 40, and the electric power charged in the battery 40 is supplied to a vehicle electrical load (headlamp, wiper, audio, etc.) 41.

  The radiator circuit 20 is provided with a radiator 21, and the radiator 21 cools the cooling water circulated by the hot water pump 22 by heat exchange with the outside air. Here, the hot water pump 22 is a mechanical pump driven by the engine 10 and is operated at a predetermined rotation speed ratio with respect to the rotation speed of the engine 10 (hereinafter referred to as engine rotation speed). The hot water pump 22 may be an electric pump driven by an electric motor instead of the mechanical pump.

  In addition, a water temperature sensor 25 and a heater 310 of a Rankine cycle 300 to be described later are disposed in a flow path on the outlet side of the engine 10 (flow path between the engine 10 and the radiator 21). The water temperature sensor 25 is a water temperature detecting means for detecting the cooling water temperature on the outlet side of the engine 10, and a temperature signal detected by the water temperature sensor 25 is output to a control device 500 (system control ECU 500a) described later. It has become. Further, cooling water flowing out from the engine 10 circulates in the heater 310.

  The radiator circuit 20 is provided with a radiator bypass passage 23 through which the coolant flows around the radiator 21, and the coolant flow through the radiator 21 and the radiator bypass passage 23 are circulated by the thermostat 24. The cooling water flow rate is adjusted.

  A heater core 31 is provided in the heater circuit 30, and cooling water (hot water) is circulated by the hot water pump 22. The heater core 31 is disposed in the air conditioning case 410 of the air conditioning unit 400, and heats the conditioned air blown by the blower 420 by heat exchange with hot water. The heater core 31 is provided with an air mix door 430, and the amount of conditioned air passing through the heater core 31 is adjusted by opening and closing the air mix door 430.

  The refrigeration cycle 200 includes a compressor 210, a condenser 220, a gas-liquid separator 230, a supercooler 231, an expansion valve 240, and an evaporator 250, which are sequentially connected in a ring to form a closed circuit. .

  The compressor 210 is a fluid device that compresses the refrigerant in the refrigeration cycle 200 to a high temperature and a high pressure. Here, the compressor 210 is a fixed capacity compressor having a predetermined discharge capacity per revolution, and is an engine (the drive source in the present invention). It is driven by a driving force of 10. That is, a pulley 211 as a driving means is fixed to the drive shaft of the compressor 210, and the driving force of the engine 10 is transmitted to the pulley 211 via the belt 12 to drive the compressor 210. The pulley 211 is provided with an electromagnetic clutch (corresponding to the clutch in the present invention) 212 that connects and disconnects between the compressor 210 and the pulley 211. The operation of the compressor 210 is turned on and off by the electromagnetic clutch 212 being engaged and disengaged. The on / off state of the electromagnetic clutch 212 is controlled by a control device 500 (air conditioner control ECU 500c) described later.

  The condenser 220 is a heat exchanger that condenses and liquefies the refrigerant by exchanging heat with the outside air, and is disposed, for example, in front of the vehicle engine room. The vehicle speed wind at the time of traveling of the vehicle flows into the heat exchange part of the condenser 220 as outside air. The inflow of outside air increases according to the vehicle speed (vehicle speed). The gas-liquid separator 230 is a receiver that separates the refrigerant condensed in the condenser 220 into gas-liquid two layers. The subcooler 231 is a heat exchanger that further cools the liquid refrigerant flowing out of the gas-liquid separator 231. The condenser 220, the gas-liquid separator 230, and the supercooler 231 are in the form of a subcool condenser having a so-called gas-liquid separator. The condenser 220, the gas-liquid separator 230, and the supercooler 231 may be a gas-liquid separator integrated subcool condenser that is integrally formed.

  The expansion valve 240 is a decompression unit that decompresses and expands the liquid refrigerant flowing out from the supercooler 231. In this embodiment, the expansion valve 240 decompresses the refrigerant in an enthalpy manner, and also superheats the refrigerant sucked into the compressor 210. A temperature type expansion valve that controls the opening degree of the throttle so that becomes a predetermined value is employed.

  The evaporator 250 is disposed in the air conditioning case 410 of the air conditioning unit 400 in the same manner as the heater core 31. The evaporator 250 is a heat exchanger that evaporates the refrigerant decompressed and expanded by the expansion valve 240 and cools the conditioned air from the blower 420 by the latent heat of evaporation at that time. The refrigerant outlet side of the evaporator 250 is connected to the suction side of the compressor 210.

  A temperature sensor 251 as temperature detecting means for detecting the temperature of the cooled conditioned air (hereinafter referred to as cooling air temperature) is provided on the downstream side of the conditioned air flow of the evaporator 250, and is detected by this temperature sensor 251. The temperature signal is output to a control device 500 (air conditioner control ECU 500c) described later. The air-conditioning air cooled by the evaporator 250 and the air-conditioning air heated by the heater core 31 have a mixing ratio varied according to the opening of the air mix door 430 and are adjusted to the indoor set temperature set by the occupant.

  The Rankine cycle 300 collects waste heat energy (cooling water heat energy) generated in the engine 10 and converts the waste heat energy into electric energy for use. Hereinafter, the Rankine cycle 300 will be described.

  The Rankine cycle 300 includes a pump 330, a heater 310, an expander 320, a condenser 220, a gas-liquid separator 230, and a supercooler 231, which are sequentially connected to form a closed circuit. Note that the condenser 220, the gas-liquid separator 230, and the supercooler 231 are commonly used in the refrigeration cycle 200, and the working fluid flowing through the Rankine cycle 300 is the same as the refrigerant in the refrigeration cycle 200. Has become.

  The pump 330 is a fluid device that circulates the refrigerant in the Rankine cycle 300, and is operated by the driving force of the electric motor 331. The operation of the electric motor 331 is controlled by a control device 500 (inverter 500d) described later.

  The heater 310 is a heat exchanger that heats the refrigerant to exchange high-temperature and high-pressure superheated vapor refrigerant by exchanging heat between the refrigerant sent from the pump 330 and the high-temperature cooling water flowing through the radiator circuit 20.

  The expander 320 is a fluid device that generates a rotational driving force (corresponding to the mechanical energy in the present invention) by the expansion of the superheated steam refrigerant heated by the heater 310. In the Rankine cycle 300, a generator 321 is connected to the expander 320, and the expander 320 and the generator 321 are integrally formed.

  The operation of the generator 321 is controlled by a control device 500 (inverter 500d) described later. That is, when the generator 321 receives a driving force from the expander 320, the number of revolutions is controlled by the inverter 500d, and the amount of power generation is adjusted accordingly. The generated power is charged into the battery 40 by the inverter 500d.

  The refrigerant discharge side of the expander 320 is connected so as to merge with the condenser 220, and is branched from the refrigeration cycle 200 on the refrigerant outflow side of the subcooler 231 and connected to the pump 330.

  The Rankine cycle 300 is provided with opening / closing means for opening / closing the refrigerant flow path in the cycle. Here, the opening / closing means is an expander stop valve 322 that opens and closes the inflow side flow path on the refrigerant inflow side of the expander 320. The expander stop valve 322 is constituted by, for example, an electromagnetic valve, and is controlled to be opened and closed by a control device 500 (system control ECU 500a) described later.

  And between the pump 330 and the heater 310, the refrigerant | coolant pressure sensor 341 as a pressure detection means which detects the refrigerant | coolant pressure (henceforth Rankine high-pressure side pressure) used as the high voltage | pressure side of Rankine cycle 300 is provided. The pressure signal detected by the refrigerant pressure sensor 341 is output to a control device 500 (system control ECU 500a) described later.

  Between the supercooler 231 and the expansion valve 240, pressure detecting means for detecting a refrigerant pressure (hereinafter referred to as a refrigeration high pressure side pressure) that becomes a high pressure side of the refrigeration cycle 200 (low pressure side of the Rankine cycle 300). A refrigerant pressure sensor 342 is provided. The pressure signal detected by the refrigerant pressure sensor 342 is output to a control device 500 (system control ECU 500a) described later.

  The control device 500 is a control means for controlling the operation of various devices of the refrigeration cycle 200 and Rankine cycle 300, and includes a system control ECU 500a, a vehicle control ECU 500b, an air conditioner control ECU 500c, and an inverter 500d.

  A vehicle control ECU 500b, an air conditioner control ECU 500c, and an inverter 500d are connected to the system control ECU 500a, and control signals are exchanged between them. The system control ECU 500a receives a detection signal from an outside air temperature sensor 510 as outside air temperature detecting means for detecting the outside air temperature.

  The system control ECU 500a performs comprehensive control of the refrigeration cycle 200 and the Rankine cycle 300, and in the simultaneous operation of the refrigeration cycle 200 and the Rankine cycle 300 as described later, the load on the refrigeration cycle 200 (hereinafter referred to as cooling load). Accordingly, the operation of the Rankine cycle 300 is controlled via the inverter 500d so that the balance between the energy for driving the compressor 210 and the energy recovered in the Rankine cycle 300 becomes positive.

  The vehicle control ECU 500b mainly controls the engine 10, and determines the fuel (engine torque) calculated from the coolant temperature from the water temperature sensor 25, the engine speed, the throttle valve opening, etc. The fuel injection amount (fuel supply amount) is controlled so that the combustion efficiency of gasoline is optimized. The vehicle control ECU 500b calculates the speed of the vehicle, that is, the vehicle speed, from the engine speed, the transmission gear ratio (not shown), and the like.

  The air conditioner control ECU 500c performs the basic operation of the refrigeration cycle 200 according to the passenger's air conditioner request, the set room temperature, the actual room temperature, the air temperature cooled by the evaporator 250, the environmental conditions (outside air temperature, solar radiation amount, etc.), etc. To control. The inverter 500d controls the operation of the Rankine cycle 300 by operating the generator 321 and the electric motor 331 and adjusting the number of rotations thereof.

  Next, the operation of the waste heat utilization apparatus 100 based on the above configuration will be described. In the waste heat utilization apparatus 100, in addition to the following refrigeration cycle single operation and Rankine cycle single operation, a combined refrigeration cycle and Rankine cycle operation can be performed.

1. The refrigeration cycle single operation control device 500 is a case where sufficient waste heat cannot be obtained during warming up immediately after the engine 10 is started, that is, when the cooling water temperature obtained by the water temperature sensor 25 is less than a predetermined cooling water temperature. When it is determined that there is an air conditioner request from the occupant, the generator 321 and the electric motor 331 are stopped (the expander 320 and the pump 330 are stopped), and the refrigeration cycle 200 is operated alone.

  The control device 500 (air conditioner control ECU 500c) calculates the necessary blowout temperature so that the actual room temperature becomes the set room temperature from the conditions such as the actual room temperature, the outside air temperature, and the amount of solar radiation during the operation of the refrigeration cycle 200. Thus, the opening degree of the air mix door 430 is controlled while controlling the operation of the compressor 210 so that the cooling air temperature in the evaporator 250 becomes a predetermined temperature (for example, 3 ° C. to 4 ° C. with hysteresis).

  In the control of the compressor 210, as shown in FIG. 2, when the cooling air temperature obtained by the temperature sensor 251 exceeds a predetermined temperature (4 ° C. on the upper limit side), the control device 500 connects the electromagnetic clutch 212. When the compressor 210 is turned on and the cooling air temperature falls below a predetermined temperature (3 ° C. on the lower limit side), the electromagnetic clutch 212 is disconnected and the compressor 210 is turned off (ON-OFF control).

2. When the Rankine cycle independent operation control device 500 determines that there is no air conditioner request and the cooling water temperature obtained by the water temperature sensor 25 is equal to or higher than the predetermined cooling water temperature and sufficient waste heat of the engine 10 is obtained, the electromagnetic clutch 212 is provided. (The compressor 210 is stopped), the electric motor 331 (pump 330) is operated (started), the expansion valve stop valve 322 is opened, and the Rankine cycle 300 is operated. Then, power is generated by the power generation action of the power generator 321 accompanying the rotational driving force of the expander 320.

  More specifically, the liquid refrigerant from the supercooler 231 is boosted by the pump 330 and sent to the heater 310, and the liquid refrigerant is heated by the high-temperature cooling water in the heater 310. The heated superheated vapor refrigerant passes through the expander stop valve 322 that is in an open state, and is sent to the expander 320. In the expander 320, the superheated steam refrigerant is expanded and reduced in an isentropic manner, a part of the heat energy and pressure energy is converted into a rotational driving force, and the generator 321 is operated by the rotational driving force extracted by the expander 320. The The electric power obtained by the generator 321 is charged to the battery 40 by the inverter 500d. The charged electric power is used for the operation of the vehicle electric load 41. Therefore, the load on the alternator 11 is reduced. Note that the refrigerant decompressed by the expander 320 is condensed by the condenser 220, separated into gas and liquid by the gas / liquid separator 230, supercooled by the subcooler 231, and sucked into the pump 330 again.

3. Refrigeration cycle / Rankine cycle combined operation When the control device 500 determines that there is an air conditioner request from a passenger and sufficient waste heat is obtained, the control device 500 operates the refrigeration cycle 200 and the Rankine cycle 300 together for air conditioning and power generation. And do both. Here, the continuous operation or intermittent operation of the Rankine cycle 300 is switched according to the load of the refrigeration cycle 200. Hereinafter, the control flowchart shown in FIG. 3 and the time charts shown in FIGS. In addition, it explains.

  First, at step S100 in FIG. 3, the control device 500 controls the operation of the refrigeration cycle 200 by turning on and off the compressor 210 by connecting and disconnecting the electromagnetic clutch 212 in the same manner as the refrigeration cycle single operation. In step S110, it is determined whether or not the cooling load is higher than a predetermined load.

  Here, the cooling load can be grasped by using various control conditions in the operation of the refrigeration cycle 200, that is, the set indoor temperature, the actual indoor temperature, the outside air temperature, and the amount of solar radiation. The higher the actual room temperature, the outside air temperature, and the amount of solar radiation, and the lower the set room temperature, the higher the cooling load. Here, among the various control conditions, the outside air temperature obtained by the outside air temperature sensor 510 is set as the cooling load. Then, as described in FIG. 20 in the “Problem” section, the point at which the balance between the increase in energy for driving the compressor 210 (compressor power) and the energy recovered by the Rankine cycle 300 (power generation energy) becomes zero. It is predetermined as a predetermined load (predetermined temperature).

  Therefore, in step S110, the outside air temperature is compared with the predetermined outside air temperature. If the outside air temperature is equal to or lower than the predetermined outside air temperature, it is determined that the cooling load is low, and the process proceeds to Rankine cycle continuous control in step S120. If the outside air temperature is higher than the predetermined outside air temperature, it is determined that the load of the refrigeration cycle 200 is high, and the routine proceeds to Rankine cycle intermittent control in step S130.

  In the Rankine cycle continuous control in step S120, as shown in FIG. 4, the Rankine cycle 300 is continuously operated regardless of the operating state of the compressor 210 that is ON-OFF controlled. That is, the electric motor 331 (pump 330) is operated, the expander stop valve 322 is opened, the refrigerant is circulated in the Rankine cycle 300, and the generator 321 generates power.

  On the other hand, in the Rankine cycle intermittent control in step S130, as shown in FIG. 5, it is determined whether or not the compressor 210 that is ON-OFF controlled in step S140 is now in the ON state. Rankine cycle 300 is stopped, and when it is OFF, Rankine cycle 300 is operated in step S160. In stopping Rankine cycle 300, expander stop valve 322 is closed, and electric motor 331 (pump 330) is stopped. Further, when the Rankine cycle 300 is operated, the electric motor 331 (pump 330) is operated as in step S120, and the expander stop valve 322 is opened. After step S150 and step S160, the process returns to step S110.

  In order to protect the Rankine cycle 300, if the Rankine high pressure side pressure obtained by the pressure sensor 341 exceeds a predetermined allowable pressure by closing the expander stop valve 332 to stop the Rankine cycle 300, The expander stop valve 322 is urgently opened.

  As described above, in this embodiment, when the cooling load is lower than the predetermined load during the combined operation of the refrigeration cycle and the Rankine cycle, the electrical energy recovered by the Rankine cycle 300 exceeds the energy for driving the compressor 210. Therefore, the energy balance can be made positive, and the waste heat of the engine 10 can be effectively utilized by performing Rankine cycle continuous control regardless of the operating state of the compressor 210.

  Further, when the cooling load is higher than the predetermined load, Rankine cycle intermittent control is performed (the Rankine cycle is ON when the compressor is OFF), so that the electric energy recovered by the expander 320 is used for driving the compressor 210. As a result, the energy balance can be positively positive as described above, and the waste heat of the engine 10 can be used effectively. Overall, the fuel consumption of the engine 10 can be improved.

  Further, when the refrigeration cycle 200 is operated, the fixed capacity compressor 210 having the electromagnetic clutch 212 is used for ON-OFF control (intermittent operation), so that the compressor 210 is turned off when the cooling load is high. In this case, the Rankine cycle intermittent control in which the Rankine cycle 300 is turned on can be easily formed.

  Further, in the Rankine cycle 300, specifically, an expander stop valve 322 as an opening / closing means is provided on the refrigerant inflow side of the expander 320 so that the expander stop valve 322 is closed during Rankine cycle intermittent control, Further, since the pump 330 is stopped thereafter, the Rankine cycle 300 can be stopped immediately and reliably.

  In addition, since the cooling load used for Rankine cycle intermittent control is grasped from the outside air temperature, it is possible to easily cope with it without using complicated detection means and detection methods.

(Second Embodiment)
A second embodiment of the present invention is shown in FIGS. The second embodiment is different from the first embodiment in that the compressor 210A is changed to a variable capacity compressor that can adjust the discharge capacity per rotation by changing the inclination angle of the swash plate, for example. The control method in the combined operation of the refrigeration cycle and Rankine cycle is changed.

  As shown in FIG. 6, in the compressor 210A, the electromagnetic clutch 212 is abolished with respect to the compressor 210 in the first embodiment, and when the discharge capacity that can be discharged is assumed to be 100%, the discharge capacity Can be continuously varied from 0% to 100%. Therefore, when the discharge capacity is 0%, the compressor 210A is rotationally driven by the driving force of the engine 10 via the belt 12, but does not substantially involve compression work (does not consume the driving force of the engine 10). It becomes a state. As shown in FIG. 7, the compressor 210A has a continuous discharge capacity by the control device 500 (air conditioner control ECU 500c) so that the cooling air temperature becomes a predetermined temperature (for example, 4 ° C.) during the operation of the refrigeration cycle 200. To be controlled.

  And the control apparatus 500 performs a refrigerating cycle and Rankine cycle combined operation based on the control flowchart shown in FIG. 8 is different from the flowchart described in FIG. 3 in that steps S100, S130, and S140 are changed to steps S100A, S130A, and S140A, respectively, and step S135 is added between steps S110 and S140A. It is assumed that

  That is, the control device 500 continuously varies the discharge capacity of the compressor 210A in step S100A in FIG. 8 (continuous capacity variable) and controls the operation of the refrigeration cycle 200. In step S110, It is determined whether or not the cooling load is higher than a predetermined load. Here, this load is determined by the outside air temperature as in the first embodiment.

  If the outside air temperature is equal to or lower than the predetermined outside air temperature in step S110, it is determined that the cooling load is in a low state, the process proceeds to the Rankine cycle continuous control in step S120, and if the outside air temperature is higher than the predetermined outside air temperature, the cooling load is high. It determines with it being in a state, and progresses to Rankine cycle intermittent control of step S130A.

  The Rankine cycle continuous control in step S120 is the same as that in the first embodiment. As shown in FIG. 9, the Rankine cycle 300 is continuously performed regardless of the operating state (discharge capacity) of the compressor 210A continuously variable. Drive. That is, the electric motor 331 (pump 330) is operated, the expander stop valve 322 is opened, the refrigerant is circulated in the Rankine cycle 300, and the generator 321 generates power.

  On the other hand, in the Rankine cycle intermittent control in step S130A, as shown in FIG. 10, in step S135, the discharge capacity control of the compressor 210A is changed from the above-mentioned continuous capacity variable to the predetermined discharge capacity (the first discharge capacity in the present invention). Corresponding control is here set to 0%), and control to alternately perform larger discharge capacity (corresponding to the second discharge capacity in the present invention, which is set to 100% here) (intermittent capacity variable) And the cooling air temperature is set to a predetermined temperature (for example, 4 ° C.). The predetermined discharge capacity is a capacity that is set so that the driving energy of the compressor 210A does not exceed the energy that can be recovered by the Rankine cycle 300, and is preferably 0% as described above. . In the intermittent capacity variable with the discharge capacities of 0% and 100%, the same operation (ON-OFF operation) as that of the fixed capacity compressor 210 of the first embodiment is performed while using the variable capacity compressor.

  In step S140A, it is determined whether or not the compressor 210A is currently in a discharge capacity 100% state. If the discharge capacity is 100%, the Rankine cycle 300 is stopped in step S150, and the discharge capacity is not 100% (discharge capacity 0). In step S160, the Rankine cycle 300 is activated.

  Thus, when the compressor 210A is a variable capacity compressor, when performing Rankine cycle intermittent control (step S130A), the discharge capacity is set to a predetermined discharge capacity (0%) and a larger discharge capacity (100%). ), The same effect as in the first embodiment can be achieved, so that the energy balance can be positively positively and the waste heat of the engine 10 is effectively utilized. can do.

  Note that the predetermined discharge capacity of the compressor 210A in step S135 and step S140A is not limited to 0%, so that the driving energy of the compressor 210A does not exceed the energy that can be recovered by the Rankine cycle 300. It may be a value close to 0%. Further, the discharge capacity on the large side is not limited to 100% as long as the cooling air temperature can be maintained at a predetermined temperature even when the cooling load is high.

(Third embodiment)
3rd Embodiment changes the determination method at the time of determining cooling load with respect to the said 1st Embodiment. Here, a plurality of pieces of information used for controlling the cooling load of the engine 10 and a plurality of pieces of information used for controlling the refrigeration cycle 200 are used in combination.

  First, vehicle speed is used as control information for the engine 10. As the vehicle speed increases, the vehicle speed wind flowing into the condenser 220 increases and heat exchange with the refrigerant is promoted, which means that the cooling load decreases as the vehicle speed increases.

  Further, as control information for the refrigeration cycle 200, in addition to the outside air temperature, the amount of solar radiation, the actual room temperature, the set room temperature, and the refrigeration high pressure are used. The meaning of the outside air temperature, the amount of solar radiation, the actual room temperature, and the set room temperature with respect to the cooling load is as described in the first embodiment. As for the refrigeration high-pressure side pressure, the higher the refrigeration high-pressure side pressure, the more the condensation capacity in the condenser 220 becomes overwork, which means that the cooling load is higher.

  FIG. 11 shows a control flowchart in the combined operation of the refrigeration cycle and Rankine cycle executed by the controller 500. Steps S111 to S115 are added to the control flowchart of FIG. 3 described in the first embodiment. It is assumed that

  If the control device 500 determines the cooling load based on the outside air temperature in step S110 after step S100 and further determines that the cooling load in this case is low (YES determination), the solar radiation amount and the vehicle speed are determined in steps S111 to S115. If the cooling load is determined from the room temperature, the set room temperature, and the refrigeration high pressure (average value of the pressure values obtained by the pressure sensor 342), and it is determined that all the cooling loads are low (YES determination), Rankin is performed in step S120. If cycle continuous control is performed and conversely it is determined that the load is low (NO determination), Rankine cycle intermittent control is performed in step S130.

  As a result, the conditions under which Rankine cycle intermittent control should be executed can be grasped in more detail and accurately, so that the accuracy of energy balance plus can be increased.

  In the determination of the cooling load, at least one of the above control information may be used, and in addition to the above, the engine speed, the coolant temperature, the engine load, and the like may be used.

(Fourth embodiment)
A fourth embodiment of the present invention is shown in FIGS. Compared to the first embodiment, the fourth embodiment grasps a high load state in which the load of the refrigeration cycle 200 is high by the expansion pressure ratio PH / PL of the expander 320 and performs Rankine cycle intermittent control. It is a thing.

  In the present embodiment, in the Rankine cycle 300, a bypass passage 323 that bypasses the expander 320 and a bypass opening / closing valve (corresponding to the bypass opening / closing means in the present invention) 324 that opens and closes the bypass passage 323 are provided. FIG. 12 is a diagram schematically showing, but here, the bypass passage 323 and the bypass on-off valve 324 are formed inside the expander 320. That is, the bypass passage 323 is formed as a communication passage that directly connects the high pressure chamber on the refrigerant suction side and the low pressure chamber on the refrigerant discharge side in the expander 320. Further, the bypass opening / closing valve 324 is disposed in the middle of the bypass passage 323 formed as the communication passage, and is configured by, for example, an electromagnetic valve, and is controlled to be opened / closed by the control device 500 (system control ECU 500a). Yes. The bypass passage 323 and the bypass opening / closing valve 324 may be provided so as to literally bypass the expander 320 itself in the refrigerant passage of the Rankine cycle 300.

  The supercooler 231 provided on the downstream side of the refrigerant flow of the gas-liquid separator 230 in the first embodiment is omitted here.

  Instead of the generator 321, a motor generator 321 </ b> A having both functions as a generator and a motor is connected to the expander 320. The motor generator 321A is controlled as an electric motor or a generator by an inverter 500d.

  The electric motor 331 for driving the pump 330 is abolished, and the pump 330 is integrally connected to the expander 320 together with the motor generator 321A. The pump 330 is started by operating the motor generator 321A as an electric motor. When the rotational driving force generated by the operation of the expander 320 exceeds the driving force required for driving the pump 330, the pump 330 is driven by the expander 320. In addition, the motor generator 321A is also driven by the expander 320, and the motor generator 321A functions as a generator to generate power.

  In the Rankine cycle 300, the refrigerant pressure sensor 341 is provided between the heater 310 and the expander 320, and the refrigerant pressure sensor 342 is provided between the gas-liquid separator 230 and the pump 330. . Similarly to the first embodiment, the refrigerant pressure sensor 341 detects the refrigerant pressure PH (Rankine high pressure side pressure) on the high pressure side of the Rankine cycle 300 (expander 320), and the refrigerant pressure sensor 342 includes the Rankine cycle 300. The refrigerant pressure PL (Rankine low pressure side pressure) on the low pressure side of the (expander 320) is detected. Pressure signals detected by the refrigerant pressure sensors 341 and 342 are output to the control device 500 (system control ECU 500a).

  Then, control device 500 calculates the ratio of refrigerant pressure PH to refrigerant pressure PL as expansion pressure ratio PH / PL, and determines the value of expansion pressure ratio PH / PL to determine the high load state of refrigeration cycle 200. I am trying to use it.

  Here, as shown in FIG. 13, when the volume of the working chamber at the time of refrigerant suction of the expander 320 is Vin and the volume of the working chamber at the time of refrigerant discharge is Vout (Vin <Vout), the expansion pressure ratio PH / PL is When the predetermined value is set, an appropriate expansion operation is obtained in the expander 320 (FIG. 13B). In the present embodiment, the predetermined value is set to 2 from the specifications of the expander 320 to be used.

  When the load on the refrigeration cycle 200 increases and the pressure in the condenser 220, that is, the Rankine low pressure PL increases, with respect to such an appropriate expansion operation, the expansion pressure ratio PH / PL during operation is a predetermined value (2). Therefore, the expander 320 is overexpanded. When the overexpansion operation is performed, the original expansion work of the expander 320 is reduced by the vacuum pump action (FIG. 13A). Moreover, when Rankine low-pressure side pressure PL falls, expansion pressure ratio PH / PL at the time of operation will become larger than predetermined value (2), and expansion machine 320 will be underexpanded operation. If the expansion is insufficient, the work that should originally be obtained by the expansion will be discarded wastefully (FIG. 13C).

  In the present embodiment, during combined operation of the refrigeration cycle and Rankine cycle, energy is prevented while preventing overexpansion operation with loss when the expansion pressure ratio PH / PL becomes smaller than a predetermined value according to the load of the refrigeration cycle 200. Control is performed so that the balance is positive.

  Hereinafter, the control contents executed by the control device 500 will be described using the flowchart shown in FIG. The flowchart in FIG. 14 is obtained by changing steps S110, S120, S130, S150, and S160 to steps S110A, S120A, S130B, S150A, and S160A with respect to the flowchart described in FIG. 3 of the first embodiment. .

  First, in step S <b> 110 </ b> A in FIG. 14, the control device 500 turns on and off the compressor 210 by connecting and disconnecting the electromagnetic clutch 212 to control the operation of the refrigeration cycle 200. It is determined whether the pressure ratio PH / PL is higher than a predetermined value.

  Here, if the expansion pressure ratio PH / PL is higher than a predetermined value, it is determined that the load of the refrigeration cycle 200 is in a low state, the process proceeds to Rankine cycle continuous control in step S120A, and the expansion pressure ratio PH / PL is a predetermined value. If it is lower, it is determined that the load of the refrigeration cycle 200 is high, and the routine proceeds to Rankine cycle intermittent control in step S130B.

  In the Rankine cycle continuous control in step S120A, the Rankine cycle 300 is continuously operated regardless of the operating state of the compressor 210 that is ON-OFF controlled. That is, the pump 330 is operated, the bypass opening / closing valve 324 is closed, the refrigerant is circulated in the Rankine cycle 300, and the motor generator 321A generates power.

  On the other hand, in the Rankine cycle intermittent control in Step S130B, it is determined whether or not the compressor 210 that is ON-OFF controlled in Step S140 is now in the ON state. If it is ON, the Rankine cycle 300 is stopped in Step S150A, If it is OFF, Rankine cycle 300 is operated in step S160A. When the Rankine cycle 300 is stopped, the bypass opening / closing valve 324 is opened, and then the motor generator 321A and the pump 330 are stopped. Further, when the Rankine cycle 300 is operated, the motor generator 321A and the pump 330 are operated as in step S120A, and the bypass on-off valve 324 is closed. After step S150A and step S160A, the process returns to step S110.

  Thus, as in the first embodiment, when the cooling load is low and the expansion pressure ratio PH / PL is larger than a predetermined value during the combined operation of the refrigeration cycle and Rankine cycle, the operation state of the compressor 210 is affected. By performing the Rankine cycle continuous control, the waste heat of the engine 10 can be effectively utilized. In addition, when the cooling load is high and the expansion pressure ratio PH / PL is smaller than a predetermined value, the Rankine cycle intermittent control (Rankine cycle ON when the compressor is OFF) performs the electrical energy recovered by the expander 320. The energy for driving the compressor 210 is not lowered, the energy balance can be positively surely, and the waste heat of the engine 10 can be effectively utilized. Overall, the fuel consumption of the engine 10 can be improved. In addition, since both the Rankine cycle continuous control and the intermittent control can operate the expander 320 in a state where there is no overexpansion operation, it is possible to efficiently recover electrical energy.

  In Rankine cycle intermittent control, the expander 320 can be easily stopped by equalizing the high pressure side and the low pressure side of the expander 320 by opening the bypass on-off valve 324 provided in the bypass passage 323. The Rankine cycle 300 can be stopped safely and reliably.

  Further, in the expander 320, if the motor generator 321A is stopped before the bypass opening / closing valve 324 is opened, the expander 320, which has become lighter in load, operates at a high speed due to the expansion of the refrigerant, and is stopped. However, since the motor generator 321A is stopped after opening the bypass opening / closing valve 324 and equalizing the high pressure side and the low pressure side of the Rankine cycle 300, the high rotation operation is prevented. Thus, the expander 320 can be stopped safely and reliably.

  In the fourth embodiment, the setting positions of the refrigerant pressure sensors 341 and 342 may be the positions described in the first embodiment. That is, the refrigerant pressure between the pump 330, the heater 310, and the expander 320 is detected as the high-pressure side pressure, and the expander 320-condenser 220-gas-liquid separator 230-pump 330 as the low-pressure side pressure. Or the refrigerant pressure between the expander 320, the condenser 220, the gas-liquid separator 230, and the expansion valve 240 may be detected.

  Moreover, the refrigerant pressure PL on the low pressure side when grasping the expansion pressure ratio PH / PL may be estimated using a physical quantity that correlates with the condensation capacity in the condenser 220. For example, the flow rate of refrigerant supplied to the condenser 220 can be estimated from the rotation speed of the expander 320 (rotation speed of the motor generator 321A0) and the rotation speed of the fixed displacement compressor 210 (engine rotation speed × pulley ratio). The low-pressure side refrigerant pressure PL can be estimated from the condensing capacity corresponding thereto. Alternatively, if the compressor 210 is a variable capacity type, the refrigerant flow rate supplied to the condenser 220 as the discharge capacity per number of revolutions of the compressor 210 x one rotation can be estimated. The refrigerant pressure PL can also be estimated from the rotation speed of the expander 320 (rotation speed of the motor generator 321A0) and the cooling load (for example, the outside air temperature, the cooling air temperature in the evaporator 250).

  Furthermore, the expansion pressure ratio P1 / P2 may be calculated as a ratio between the heating amount in the heater 210 and the heat radiation amount in the condenser 220. The heating amount in the heater 210 can be calculated from the temperature and flow rate of the engine cooling water flowing through the heater 210, and the heat release amount in the condenser 220 is the refrigerant flow rate, the outside air temperature, and the outside air speed flowing through the condenser 220. It can be calculated from (vehicle speed).

(Other embodiments)
In the first to third embodiments, the expander stop valve 322 used when stopping the Rankine cycle 300 is provided on the refrigerant inflow side of the expander 320. However, the present invention is not limited to this, and the refrigerant inflow side of the pump 330 or the like. Alternatively, it may be provided in another part.

  Further, the generator 321 is operated by the driving force recovered by the expander 320 and stored in the battery 40 as electric energy. However, it is stored as mechanical energy such as kinetic energy by a flywheel or elastic energy by a spring. Also good.

  Further, although the vehicle engine (internal combustion engine) 10 is used as the heat generating device, the heat generating device is not limited to this. For example, an external combustion engine, a fuel cell stack of a fuel cell vehicle, various motors, an inverter, and the like generate heat during operation. Along with this, any part of the heat for temperature control (those that generate waste heat) can be widely applied. In that case, the heating source for the heater 310 is a fluid for cooling various waste heat equipment.

It is a schematic diagram which shows the whole waste heat utilization apparatus in 1st Embodiment. It is a time chart which shows the relationship between the electromagnetic clutch at the time of the refrigerating cycle control in 1st Embodiment, and cooling air temperature. It is a control flowchart for performing the refrigerating cycle and Rankine cycle combined operation in 1st Embodiment. It is a time chart which shows the relationship between the electromagnetic clutch at the time of Rankine cycle continuous control in 1st Embodiment, and the operating state of a Rankine cycle. It is a time chart which shows the relationship between the electromagnetic clutch at the time of Rankine cycle intermittent control in 1st Embodiment, and the operating state of a Rankine cycle. It is a schematic diagram which shows the whole waste heat utilization apparatus in 2nd Embodiment. It is a time chart which shows the relationship between the compressor discharge capacity | capacitance at the time of the refrigerating cycle control in 2nd Embodiment, and cooling air temperature. It is a control flowchart for performing the refrigerating cycle and Rankine cycle combined operation in 2nd Embodiment. It is a time chart which shows the relationship between the compressor discharge capacity | capacitance at the time of Rankine cycle continuous control in 2nd Embodiment, and the operating state of a Rankine cycle. It is a time chart which shows the relationship between the compressor discharge capacity | capacitance at the time of Rankine cycle intermittent control in 2nd Embodiment, the operating state of Rankine cycle, and cooling air temperature. It is a control flowchart for performing the refrigerating cycle and Rankine cycle combined operation in 3rd Embodiment. It is a schematic diagram which shows the whole waste heat utilization apparatus in 4th Embodiment. It is a pressure-volume diagram which shows the operating state of an expander. It is a control flowchart for performing the refrigerating cycle and Rankine cycle combined operation in 4th Embodiment. It is a graph which shows the relationship between a cooling load and compressor power. It is a Mollier diagram (Ph diagram) showing an operating state of the refrigeration cycle. It is a graph which shows the relationship between the cooling load at the time of making a refrigerating cycle and a Rankine cycle drive simultaneously, and compressor power. It is a Mollier diagram (Ph diagram) which shows the operating state of both cycles at the time of operating a refrigerating cycle and a Rankine cycle simultaneously. It is a graph which shows the heat dissipation characteristic of the condenser with respect to outside temperature. It is a graph which shows the energy increase for compressor power with respect to cooling load, and the recovery energy by Rankine cycle.

Explanation of symbols

10 Engine (heat generating equipment, internal combustion engine, drive source)
100 Waste heat utilization device 200 Refrigeration cycle 210 Compressor 212 Electromagnetic clutch (clutch)
220 condenser 250 evaporator 300 Rankine cycle 320 expander 321A motor generator (generator)
322 Expander stop valve (opening / closing means)
323 Bypass passage 324 Bypass opening / closing valve (Bypass opening / closing means)
330 Pump 500 Control device (control means)

Claims (32)

A refrigeration cycle (200) having a compressor (210) that compresses the low-pressure refrigerant sucked from the evaporator (250) side that cools the conditioned air into high-temperature and high-pressure and discharges it to the condenser (220) side;
Rankine cycle (in which the condenser (220) is shared, and mechanical energy is recovered by the expander (320) by expansion of the refrigerant pumped by the pump (330) and heated by the waste heat of the heat generating device (10) 300),
In the waste heat utilization apparatus having control means (500) for controlling the operation of the refrigeration cycle (200) and the Rankine cycle (300),
The control means (500) continuously operates the Rankine cycle (300) regardless of the operating state of the compressor (210) when the load of the refrigeration cycle (200) is lower than a predetermined load. While performing the control,
A waste heat utilization apparatus that performs intermittent control for intermittently operating the Rankine cycle (300) when the load of the refrigeration cycle (200) is in a high load state where the load is higher than a predetermined load.   In the high load state, a machine in which an increase in driving energy of the compressor (210) due to simultaneous operation of the compressor (210) and the expander (320) is recovered by the expander (320). The waste heat utilization apparatus according to claim 1, wherein the waste heat utilization apparatus is in a state in which the thermal energy is exceeded.   The control means (500) intermittently operates the compressor (210) when performing the intermittent control, and intermittently operates the Rankine cycle (300) so as to be reverse to the intermittent operation. The waste heat utilization apparatus according to claim 1 or 2, characterized in that: The compressor (210) is a fixed capacity compressor (210) that is driven by a drive source (10) and has a predetermined discharge capacity per rotation.
The control means (500) performs the intermittent operation of the compressor (210) by intermittently engaging a clutch (212) with the drive source (10) or turning on and off the drive source (10). The waste heat utilization apparatus according to claim 3. The compressor (210) is a variable capacity compressor (210) capable of adjusting a discharge capacity per one rotation,
The control means (500) performs intermittent operation of the compressor (210) by switching between a first discharge capacity and a second discharge capacity larger than the first discharge capacity. Item 4. A waste heat utilization apparatus according to Item 3. Opening and closing means (322) for opening and closing the refrigerant flow path of the refrigerant circulating in the Rankine cycle (300),
The said control means (500) closes the said opening-and-closing means (322), when stopping the said Rankine cycle (300) in execution of the said intermittent control, The any one of Claims 3-5 Waste heat utilization equipment described in 1.   The waste heat utilization apparatus according to claim 6, wherein the control means (500) stops the pump (330) after the opening / closing means (322) is closed.   The waste heat utilization apparatus according to claim 6 or 7, wherein the opening / closing means (322) is provided on a refrigerant inflow side of the expander (320). A bypass passage (323) for bypassing the expander (320);
Bypass opening and closing means (324) for opening and closing the bypass passage (323),
The said control means (500) opens the said bypass opening / closing means (324), when stopping the said Rankine cycle (300) in the case of execution of the said intermittent control. Waste heat utilization apparatus as described in one. A generator (321A) connected to the expander (320) and driven by the mechanical energy to generate electricity;
The waste heat utilization apparatus according to claim 9, wherein the control means (500) stops the generator (321A) after opening the bypass opening / closing means (324).   The waste heat utilization apparatus according to any one of claims 1 to 10, wherein the control means (500) grasps a load of the refrigeration cycle (200) based on an outside air temperature.   The said control means (500) grasps | ascertains the load of the said refrigerating cycle (200) from the information for the said heat generating apparatus (10) control, and the information for the said refrigerating cycle (200) control. The waste heat utilization apparatus according to any one of claims 1 to 10. The heat generating device (10) is an internal combustion engine (10) for a vehicle,
The information for controlling the heat generating device (10) is at least one of the speed of the vehicle, the rotational speed of the internal combustion engine (10), the outside air temperature, and the cooling medium temperature of the internal combustion engine (10). The waste heat utilization apparatus according to claim 12, wherein the apparatus is a waste heat utilization apparatus.   The information for controlling the refrigeration cycle (200) is at least one of an indoor temperature, a target indoor temperature, an air-conditioning air temperature cooled by the evaporator (250), and a refrigerant pressure in the refrigeration cycle (200). The waste heat utilization apparatus according to claim 12.   The control means (500) sets the high load state to a high pressure side pressure (PH) which is a high pressure side of the expander (320) with respect to a low pressure side pressure (PL) which is a low pressure side of the expander (320). It is grasped | ascertained by the expansion pressure ratio (PH / PL) shown by a ratio, The waste heat utilization apparatus as described in any one of Claims 1-10 characterized by the above-mentioned.   The control means (500) sets the expansion pressure ratio (PH / PL) to the waste heat temperature of the heating device (10) and the refrigerant in the condenser (220) downstream of the expander (320). The waste heat utilization apparatus according to claim 15, wherein the waste heat utilization apparatus is estimated from a flow rate of air, a temperature of outside air in the condenser (220), and a speed of the outside air. A refrigeration cycle (200) having a compressor (210) that compresses the low-pressure refrigerant sucked from the evaporator (250) side that cools the conditioned air into high-temperature and high-pressure and discharges it to the condenser (220) side;
Rankine cycle (in which the condenser (220) is shared, and mechanical energy is recovered by the expander (320) by expansion of the refrigerant pumped by the pump (330) and heated by the waste heat of the heat generating device (10) 300) and a method for controlling a waste heat utilization apparatus,
When the load of the refrigeration cycle (200) is lower than a predetermined load, continuous control for continuously operating the Rankine cycle (300) regardless of the operating state of the compressor (210) is performed.
Control of a waste heat utilization apparatus, wherein intermittent control is performed to intermittently operate the Rankine cycle (300) when the load of the refrigeration cycle (200) is higher than a predetermined load. Method.   In the high load state, a machine in which an increase in driving energy of the compressor (210) due to simultaneous operation of the compressor (210) and the expander (320) is recovered by the expander (320). The method for controlling a waste heat utilization apparatus according to claim 17, wherein the control method is a state in which the energy exceeds the dynamic energy.   When the intermittent control is executed, the compressor (210) is intermittently operated, and the Rankine cycle (300) is intermittently operated so as to be reverse to the intermittent operation. The control method of the waste heat utilization apparatus of Claim 17 or Claim 18. The compressor (210) is a fixed capacity compressor (210) that is driven by a drive source (10) and has a predetermined discharge capacity per rotation.
The intermittent operation of the compressor (210) is performed by intermittent connection of a clutch (212) with the drive source (10) or ON / OFF of the drive source (10). Control method of waste heat utilization equipment. The compressor (210) is a variable capacity compressor (210) capable of adjusting a discharge capacity per one rotation,
The waste heat utilization according to claim 19, wherein the intermittent operation of the compressor (210) is performed by switching between a first discharge capacity and a second discharge capacity larger than the first discharge capacity. Control method of the device.   The refrigerant flow path of the refrigerant circulating in the Rankine cycle (300) is closed when the Rankine cycle (300) is stopped when the intermittent control is executed. A method for controlling a waste heat utilization apparatus according to claim 1.   The method for controlling a waste heat utilization apparatus according to claim 22, wherein the pump (330) is stopped after the refrigerant flow path is closed.   24. The method for controlling a waste heat utilization apparatus according to claim 22 or 23, wherein a refrigerant inflow side of the expander (320) is closed in the refrigerant flow path.   The flow of the refrigerant to the expander (320) is bypassed when the Rankine cycle (300) is stopped when the intermittent control is executed. Control method of waste heat utilization apparatus as described in 1. A generator (321A) connected to the expander (320) and driven by the mechanical energy to generate electricity;
The method of controlling a waste heat utilization apparatus according to claim 25, wherein the generator (321A) is stopped after the flow of the refrigerant to the expander (320) is bypassed.   27. The method for controlling a waste heat utilization apparatus according to any one of claims 17 to 26, wherein a load of the refrigeration cycle (200) is grasped based on an outside air temperature.   The load of the refrigeration cycle (200) is determined in combination from the information for controlling the heat generating device (10) and the information for controlling the refrigeration cycle (200). 26. A method for controlling a waste heat utilization apparatus according to any one of 26. The heat generating device (10) is an internal combustion engine (10) for a vehicle,
The information for controlling the heat generating device (10) is at least one of the speed of the vehicle, the rotational speed of the internal combustion engine (10), the outside air temperature, and the cooling medium temperature of the internal combustion engine (10). The method for controlling a waste heat utilization apparatus according to claim 28, characterized in that:   The information for controlling the refrigeration cycle (200) is at least one of an indoor temperature, a target indoor temperature, an air-conditioning air temperature cooled by the evaporator (250), and a refrigerant pressure in the refrigeration cycle (200). The method for controlling a waste heat utilization apparatus according to claim 28.   The high load state is an expansion pressure ratio (P1) indicated by a ratio of a high pressure side pressure (P1) which is a high pressure side of the expander (320) to a low pressure side pressure (P2) which is a low pressure side of the expander (320). The control method of the waste heat utilization apparatus according to any one of claims 17 to 26, wherein the control is performed by P1 / P2).   The expansion pressure ratio (P1 / P2) is the waste heat temperature of the heat generating device (10), the flow rate of the refrigerant in the condenser (220) on the downstream side of the expander (320), the condenser (220 32. The method of controlling a waste heat utilization apparatus according to claim 31, wherein the temperature is estimated from the temperature of the outside air and the speed of the outside air.

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