In-vehicle temperature control system

Abstract

To properly control a temperature of an inter-media heat exchanger which causes a heat medium circulating through a heat circuit from a refrigerant circulating through a refrigeration circuit to release heat.SOLUTION: An on-vehicle temperature control system 1 comprises: a refrigeration circuit 2 capable of circulating a refrigerant through a water cooling condenser 22, which causes heat to be released from the refrigerant to a heat medium, and through an evaporator 26 which makes the refrigerant evaporate; a high-temperature circuit 4 capable of circulating the heat medium through an engine heat exchanger 43 which heats the heat medium with waste heat from a heater core 42 for warming the inside of a cabin, the cooling condenser 22, and an internal combustion engine 110, the high-temperature circuit 4 having a fourth electromagnetic adjustment valve 54 for adjusting inflow of the heat medium discharged from the engine heat exchanger 43 to the water cooling condenser 22; and an ECU 61 which controls the fourth electromagnetic adjustment valve 54 in such a manner that the inflow of the heat medium to the water cooling condenser 22 is stopped when a temperature of the heat medium in the water cooling condenser 22 reaches a predetermined upper limit temperature, and the heat medium is caused to flow into the water cooling condenser 22 when the temperature reaches a predetermined lower limit temperature.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an in-vehicle temperature control system.

Background Art

[0002] Conventionally, in a hybrid vehicle, when the start of driving of an engine is predicted during driving by a motor and warming up of the engine (raising the temperature of cooling water) is required, the waste heat of a refrigeration cycle for air conditioning is used to heat the engine cooling water. This is known (Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When driving by driving an internal combustion engine, the cooling water for cooling the internal combustion engine circulates through the heater core. During this time, if no air conditioning request or battery cooling request is issued, the flow of the cooling water to a heat exchanger (water-cooled condenser) that exchanges heat between the cooling water of the internal combustion engine and the refrigerant of the refrigeration cycle is stopped, and the water temperature of the cooling water in the heat exchanger decreases by natural heat dissipation.

[0005] Therefore, in the technology described in the above patent document, when heating the engine coolant by utilizing the waste heat of the refrigeration cycle for air conditioning, at the beginning of starting the water flow of the coolant to the heat exchanger, due to the exchange of the high-temperature coolant that had been circulating through the internal combustion engine and the low-temperature coolant in the heat exchanger that dissipated heat due to the stop of water flow, heat loads are applied to the internal combustion engine, the heat exchanger, the heater core, etc., and there is a problem that thermal distortion occurs in these devices. Further, when a heating request is issued while the inside of the heat exchanger is in a low-temperature state, the low-temperature coolant in the heat exchanger flows into the heater core, resulting in a time lag until warm air comes out from the warm air outlet in the vehicle interior, which may give a sense of discomfort to the vehicle occupants.

[0006] On the other hand, if the coolant of the warm-up internal combustion engine continues to flow through the heat exchanger, the heat exchanger will become hotter than necessary, and when a battery cooling request or a cooling request is issued, there will be a problem that the efficiency of heat exchange decreases.

[0007] Furthermore, in the technology described in the above patent document, when the internal combustion engine is stopped, the refrigeration cycle functions as a heat pump and absorbs heat from the coolant of the internal combustion engine. However, since the heat pump takes a certain amount of time to pump heat, if the water temperature of the heat exchanger decreases when the internal combustion engine stops, there is a problem that the temperature of the heater core decreases before the heat is pumped up. For this reason, in order to heat the vehicle interior, it becomes necessary to restart the internal combustion engine to heat the coolant, or in order to pump more heat from the refrigeration cycle, it becomes necessary to rotate the compressor of the refrigeration cycle at a higher speed than necessary, leading to problems such as deteriorated fuel consumption and deteriorated NV (Noise·Vibration).

[0008] In view of the above problems, an object of the present disclosure is to provide an in-vehicle temperature control system capable of appropriately controlling the temperature of a medium-to-medium heat exchanger that radiates heat from a refrigerant circulating in a refrigeration circuit to a heat medium circulating in a heat circuit.

Means for Solving the Problems

[0009] The gist of the present disclosure is as follows.

[0010] (1) A refrigeration circuit capable of circulating the refrigerant through an inter - medium heat exchanger that dissipates heat from the refrigerant to a heat medium and an evaporator that evaporates the refrigerant, A heat circuit capable of circulating the heat medium through a heater core for heating the vehicle interior, the inter - medium heat exchanger, and an engine heat exchanger that heats the heat medium by the exhaust heat of an internal combustion engine, the heat circuit having an adjustment valve for adjusting the inflow of the heat medium discharged from the engine heat exchanger to the inter - medium heat exchanger, A control device that stops the inflow of the heat medium to the inter - medium heat exchanger when the temperature of the heat medium in the inter - medium heat exchanger reaches a predetermined upper limit temperature, and controls the adjustment valve to allow the heat medium to flow into the inter - medium heat exchanger when the temperature reaches a predetermined lower limit temperature, An in - vehicle temperature control system comprising the above.

[0011] (2) When stopping the internal combustion engine during vehicle operation, the control device controls the adjustment valve to allow the heat medium to flow into the inter - medium heat exchanger, and stops the internal combustion engine after raising the temperature of the heat medium in the inter - medium heat exchanger. The in - vehicle temperature control system according to (1) above.

[0012] (3) The control device allows the heat medium to flow into the inter - medium heat exchanger until the temperature of the heat medium in the inter - medium heat exchanger reaches a first predetermined temperature or until it is estimated that the temperature of the heat medium in the heat circuit reaches a second predetermined temperature, and then stops the internal combustion engine. The in - vehicle temperature control system according to (2) above.

Advantages of the Invention

[0013] According to the present disclosure, an in - vehicle temperature control system capable of appropriately controlling the temperature of an inter - medium heat exchanger that dissipates heat from a refrigerant circulating in a refrigeration circuit to a heat medium circulating in a heat circuit is provided.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Embodiments for Carrying Out the Invention

[0015] Hereinafter, several embodiments according to the present invention will be described with reference to the drawings. However, these descriptions are merely illustrative of preferred embodiments of the present invention and are not intended to limit the present invention to such specific embodiments. In the following description, the same reference numerals are assigned to similar components.

[0016] <Configuration of the Vehicle> FIG. 1 is a diagram schematically showing the configuration of a vehicle 100 equipped with an in-vehicle temperature control system 1 according to one embodiment. In FIG. 1, the left side shows the front of the vehicle 100, and the right side shows the rear of the vehicle 100. As shown in FIG. 1, the vehicle 100 includes an internal combustion engine 110, a motor generator (MG) 112, and a power split mechanism 116. In addition, the vehicle 100 includes a power control unit (PCU) 118 electrically connected to the MG 112 and a battery 120 electrically connected to the PCU 118.

[0017] The internal combustion engine 110 is a prime mover that burns fuel inside the engine and converts the thermal energy of the combustion gas into mechanical energy. The internal combustion engine 110 is connected to the power split mechanism 116, and the output of the internal combustion engine 110 is used to drive the vehicle 100 or generate electricity with the MG 112.

[0018] The MG 112 functions as an electric motor and a generator. The MG 112 is connected to the power split mechanism 116 and is used to drive the vehicle 100 or perform regeneration when braking the vehicle 100. In this embodiment, the MG 112 having a power generation function is used as the motor for driving the vehicle 100, but a motor without a power generation function may also be used.

[0019] The PCU 118 is connected between the battery 120 and the MG 112 and controls the power supplied to the MG 112. The PCU 118 has heat-generating components such as an inverter that drives a motor, a boost converter that controls voltage, and a DC-DC converter that steps down high voltage. The battery 120 is connected to the PCU 118 and the MG 112 and supplies power for driving the vehicle 100 to the MG 112.

[0020] In this embodiment, the internal combustion engine 110, the MG 112, and the PCU 118 are arranged in front of the vehicle 100, that is, in front of the passenger compartment. On the other hand, the battery 120 is arranged in the center of the vehicle 100, that is, below the passenger compartment.

[0021] Note that the vehicle 100 may be any type of vehicle as long as it includes the internal combustion engine 110 and the MG (or motor) 112. Therefore, for example, the vehicle 100 may be configured such that the internal combustion engine is used only for power generation and only the motor drives the vehicle 100. Also, for example, the vehicle 100 may be configured to have two MGs, one mainly used for driving the vehicle 100 and the other mainly used for power generation.

[0022] <Configuration of In-vehicle Temperature Control System> With reference to FIGS. 1 and 2, the configuration of an in-vehicle temperature control system 1 according to one embodiment will be described. FIG. 2 is a configuration diagram schematically showing the in-vehicle temperature control system 1. The in-vehicle temperature control system 1 includes a refrigeration circuit 2, a low-temperature circuit 3, a high-temperature circuit 4, and a control device 6. The refrigeration circuit 2, the low-temperature circuit 3, and the high-temperature circuit 4 function as heat circuits that exchange heat with the outside of the circuit.

[0023] ≪Refrigeration Circuit≫ First, the refrigeration circuit 2 will be described. The refrigeration circuit 2 includes a compressor 21, a refrigerant pipe 22a of a water-cooled condenser 22, a receiver 23, a first expansion valve 24, a second expansion valve 25, an evaporator 26, a refrigerant pipe 27a of a chiller 27, a first electromagnetic control valve 28, and a second electromagnetic control valve 29. The refrigeration circuit 2 is configured to realize a refrigeration cycle by circulating the refrigerant through these components. As the refrigerant, for example, any substance generally used as a refrigerant in a refrigeration cycle, such as hydrofluorocarbon (e.g., HFC-134a), is used.

[0024] Further, the refrigeration circuit 2 has a basic refrigeration flow path 2a, an evaporator flow path 2b, and a chiller flow path 2c. The evaporator flow path 2b and the chiller flow path 2c are provided in parallel with each other and are respectively connected to the basic refrigeration flow path 2a.

[0025] In the basic refrigeration flow path 2a, in the refrigerant circulation direction, the compressor 21, the refrigerant pipe 22a of the water-cooled condenser 22, and the receiver 23 are provided in this order. In the evaporator flow path 2b, in the refrigerant circulation direction, the first electromagnetic control valve 28, the first expansion valve 24, and the evaporator 26 are provided in this order. In addition, in the chiller flow path 2c, the second electromagnetic control valve 29, the second expansion valve 25, and the refrigerant pipe 27a of the chiller 27 are provided in this order.

[0026] The compressor 21 functions as a compressor that compresses the refrigerant. In the present embodiment, the compressor 21 is electric, and its discharge capacity is configured to be steplessly changed by adjusting the supply power to the compressor 21. In the compressor 21, the refrigerant that is low-temperature and low-pressure and mainly gaseous flowing out from the evaporator 26 or the chiller 27 is adiabatically compressed to be changed into a refrigerant that is high-temperature and high-pressure and mainly gaseous.

[0027] The water-cooled condenser 22 has a refrigerant pipe 22a and a cooling water pipe 22b. The water-cooled condenser 22 functions as an inter-medium heat exchanger that dissipates heat from the refrigerant to the cooling water flowing through the cooling water pipe 22b of the high-temperature circuit 4 described later to condense the refrigerant. Looking at it from another perspective, the water-cooled condenser 22 functions as a heating unit that heats the cooling water of the high-temperature circuit 4 using heat other than the exhaust heat of the internal combustion engine 110. The refrigerant pipe 22a of the water-cooled condenser 22 functions as a condenser that condenses the refrigerant in the refrigeration cycle. Also, in the refrigerant pipe 22a of the water-cooled condenser 22, the refrigerant that is high-temperature, high-pressure, and mainly gaseous and flows out from the compressor 21 is changed into a high-temperature, high-pressure, mainly liquid refrigerant by being cooled isobarically.

[0028] The receiver 23 stores the refrigerant condensed by the refrigerant pipe 22a of the water-cooled condenser 22. Also, since the water-cooled condenser 22 cannot necessarily liquefy all of the refrigerant, the receiver 23 is configured to separate gas and liquid. Only the liquid refrigerant from which the gaseous refrigerant has been separated flows out from the receiver 23.

[0029] The first expansion valve 24 and the second expansion valve 25 function as expanders that expand the refrigerant. These expansion valves 24 and 25 have a small-diameter passage, and by spraying the refrigerant from this small-diameter passage, the pressure of the refrigerant is rapidly reduced. The first expansion valve 24 sprays the liquid refrigerant supplied from the receiver 23 into the evaporator 26 in a mist form. Similarly, the second expansion valve 25 sprays the liquid refrigerant supplied from the receiver 23 into the refrigerant pipe 27a of the chiller 27 in a mist form. In these expansion valves 24 and 25, the high-temperature, high-pressure liquid refrigerant flowing out from the receiver 23 is decompressed and partially vaporized, thereby being changed into a low-temperature, low-pressure mist-like refrigerant.

[0030] The evaporator 26 functions as an evaporator that absorbs heat from the refrigerant to evaporate the refrigerant. Specifically, the evaporator 26 absorbs heat from the air around the evaporator 26 and transfers it to the refrigerant to evaporate the refrigerant. Therefore, in the evaporator 26, the low-temperature and low-pressure mist-like refrigerant flowing out from the first expansion valve 24 is changed into a low-temperature and low-pressure gaseous refrigerant by evaporation. As a result, the air around the evaporator 26 is cooled, and the interior of the vehicle can be air-conditioned.

[0031] The chiller 27 includes a refrigerant pipe 27a and a cooling water pipe 27b. The chiller 27 functions as an intermediate heat exchanger that absorbs heat from the cooling water flowing through the cooling water pipe 27b of the low-temperature circuit 3 described later and transfers it to the refrigerant to evaporate the refrigerant. The refrigerant pipe 27a of the chiller 27 functions as an evaporator that evaporates the refrigerant. Also, in the refrigerant pipe 27a of the chiller 27, the low-temperature and low-pressure mist-like refrigerant flowing out from the second expansion valve 25 is changed into a low-temperature and low-pressure gaseous refrigerant by evaporation. As a result, the cooling water of the low-temperature circuit 3 is cooled.

[0032] The first electromagnetic control valve 28 and the second electromagnetic control valve 29 are used to change the flow mode of the refrigerant in the refrigeration circuit 2. As the opening degree of the first electromagnetic control valve 28 increases, the amount of refrigerant flowing into the evaporator flow path 2b increases, and thus the amount of refrigerant flowing into the evaporator 26 increases. Also, as the opening degree of the second electromagnetic control valve 29 increases, the amount of refrigerant flowing into the chiller flow path 2c increases, and thus the amount of refrigerant flowing into the chiller 27 increases. Note that any valve may be provided instead of these electromagnetic control valves 28 and 29 as long as the flow rate of the refrigerant flowing from the basic refrigeration flow path 2a into the evaporator flow path 2b and the chiller flow path 2c can be adjusted.

[0033] In this embodiment, the refrigeration circuit 2 has only the water-cooled condenser 22 as a heat exchanger that releases heat from the refrigerant in the refrigeration circuit 2 to the outside. However, the refrigeration circuit 2 may have other heat exchangers that release heat from the refrigerant to the outside (for example, outside air).

[0034] ≪Low-temperature circuit≫ Next, the low-temperature circuit 3 will be described. The low-temperature circuit 3 includes a first pump 31, a cooling water pipe 27b of the chiller 27, a low-temperature radiator 32, a first three-way valve 33, and a second three-way valve 34. In addition, the low-temperature circuit 3 includes a battery heat exchanger 35, a PCU heat exchanger 36, and an MG heat exchanger 37. In the low-temperature circuit 3, cooling water circulates through these components. Note that any other heat medium may be used instead of the cooling water in the low-temperature circuit 3.

[0035] The low-temperature circuit 3 has a low-temperature basic flow path 3a, a low-temperature radiator flow path 3b, and a heat-generating device flow path 3c. The low-temperature radiator flow path 3b and the heat-generating device flow path 3c are provided in parallel with each other and are each connected to the low-temperature basic flow path 3a.

[0036] In the low-temperature basic flow path 3a, in the circulation direction of the cooling water, the first pump 31, the cooling water pipe 27b of the chiller 27, and the battery heat exchanger 35 are provided in this order. Further, a battery bypass flow path 3d provided so as to bypass the battery heat exchanger 35 is connected to the low-temperature basic flow path 3a. A first three-way valve 33 is provided at the connection portion between the low-temperature basic flow path 3a and the battery bypass flow path 3d.

[0037] Also, a low-temperature radiator 32 is provided in the low-temperature radiator flow path 3b. In the heat-generating device flow path 3c, in the circulation direction of the cooling water, the PCU heat exchanger 36 and the MG heat exchanger 37 are provided in this order. A heat exchanger for exchanging heat with heat-generating devices other than the PCU and the MG may be provided in the heat-generating device flow path 3c. A second three-way valve 34 is provided between the low-temperature basic flow path 3a and the low-temperature radiator flow path 3b and the heat-generating device flow path 3c.

[0038] The first pump 31 pumps the cooling water circulating in the low-temperature circuit 3. In the present embodiment, the first pump 31 is an electric water pump, and its discharge capacity is configured to be steplessly changed by adjusting the supply power to the first pump 31.

[0039] The low-temperature radiator 32 is a heat exchanger that performs heat exchange between the cooling water circulating in the low-temperature circuit 3 and the outside air (ambient air) of the vehicle 100. The low-temperature radiator 32 is configured to dissipate heat from the cooling water to the outside air when the temperature of the cooling water is higher than the temperature of the outside air, and to absorb heat from the outside air to the cooling water when the temperature of the cooling water is lower than the temperature of the outside air.

[0040] The first three-way valve 33 is configured to selectively circulate the cooling water flowing out from the cooling water pipe 27b of the chiller 27 between the battery heat exchanger 35 and the battery bypass flow path 3d. The second three-way valve 34 is configured to selectively circulate the cooling water flowing out from the low-temperature basic flow path 3a between the low-temperature radiator flow path 3b and the heat-generating equipment flow path 3c.

[0041] The battery heat exchanger 35 is configured to exchange heat with the battery 120 of the vehicle 100. The PCU heat exchanger 36 is configured to exchange heat with the PCU 118 of the vehicle 100. Also, the MG heat exchanger 37 is configured to exchange heat with the MG 112 of the vehicle 100.

[0042] In this embodiment, the chiller 27 is provided in the refrigeration circuit 2 and the low-temperature circuit 3, and the chiller 27 functions as an intermediate heat exchanger that transfers heat from the cooling water of the low-temperature circuit 3 to the refrigerant of the refrigeration circuit 2. However, a heat exchanger that exchanges heat with the gas in the outside air of the vehicle and transfers heat from the gas in the outside air to the refrigerant of the refrigeration circuit 2 may be provided in the refrigeration circuit 2 instead of the chiller 27. In this case, the low-temperature circuit 3 is not provided in the in-vehicle temperature control system 1, and thus the cooling of the battery 120, the PCU 118, and the MG 112 is performed by a mechanism other than the in-vehicle temperature control system 1.

[0043] <<High-temperature circuit>> Next, the high-temperature circuit 4 will be described. The high-temperature circuit 4 includes a second pump 41, a heater core 42, an engine heat exchanger 43, a high-temperature radiator 44, a thermostad 46, a third pump 51, a third electromagnetic control valve 52, a fourth electromagnetic control valve 54, a fifth electromagnetic control valve 56, and a cooling water pipe 22b of the water-cooled condenser 22. Cooling water circulates through these components in the high-temperature circuit 4. Note that this cooling water is an example of a heat medium, and any other heat medium may be used instead of the cooling water in the high-temperature circuit 4.

[0044] Further, the high-temperature circuit 4 has a first communication path 4a and a second communication path 4b.

[0045] The first communication path 4a communicates with the downstream side of the engine heat exchanger 43 to be described later and the inlet of the cooling water pipe 22b of the water-cooled condenser 22, and also communicates with the inlet of the heater core 42 and the inlet of the high-temperature radiator 44. Specifically, the first communication path 4a includes a condenser inflow path 4a1 that communicates with the inlet of the cooling water pipe 22b of the water-cooled condenser 22, a high-temperature radiator inflow path 4a2 that communicates with the high-temperature radiator 44, an engine outflow path 4a3 that communicates with the engine heat exchanger 43, and a core inflow path 4a4 that communicates with the condenser inflow path 4a1, the high-temperature radiator inflow path 4a2, and the engine outflow path 4a3 and also communicates with the inlet of the heater core 42. Therefore, the first communication path 4a can cause the cooling water flowing out from the engine heat exchanger 43 to flow into the heater core 42 and / or the high-temperature radiator 44 and the water-cooled condenser 22.

[0046] The second communication path 4b communicates with the outlet of the heater core 42 and the outlet of the high-temperature radiator 44, and also communicates with the upstream side of the engine heat exchanger 43 and the outlet of the cooling water pipe 22b of the water-cooled condenser 22. Specifically, the second communication path 4b includes a condenser outflow passage 4b1 that communicates with the outlet of the cooling water pipe 22b of the water-cooled condenser 22, a high-temperature radiator outflow passage 4b2 that communicates with the high-temperature radiator 44, an engine inflow passage 4b3 that communicates with the engine heat exchanger 43, and a heater core outflow passage 4b4 that communicates with the outlet of the heater core 42. Therefore, the second communication path 4b can cause the cooling water flowing out from the heater core 42, the cooling water flowing out from the high-temperature radiator 44, and the cooling water flowing out from the water-cooled condenser 22 to flow into the engine heat exchanger 43.

[0047] As will be described later, when the second pump 41 is driven during the operation stop of the internal combustion engine 110 to circulate the cooling water between the heater core 42 and the water-cooled condenser 22, the cooling water flows into the water-cooled condenser 22 from the condenser outflow passage 4b1, and the cooling water is discharged from the water-cooled condenser 22 to the condenser inflow passage 4a1.

[0048] As described above, in this embodiment, the high-temperature circuit 4 includes a first communication path 4a that communicates with the downstream side of the engine heat exchanger 43 and the inlet of the water-cooled condenser 22 and the inlets of the heater core 42 and the high-temperature radiator 44 to circulate the cooling water from the engine heat exchanger 43 to the heater core 42, the high-temperature radiator 44, and / or the water-cooled condenser 22, and a second communication path 4b that communicates with the upstream side of the engine heat exchanger 43 and the outlets of the water-cooled condenser 22, the heater core 42, and the high-temperature radiator 44 to circulate the cooling water from the heater core 42, the high-temperature radiator 44, and / or the water-cooled condenser 22 to the engine heat exchanger 43.

[0049] The second pump 41 pumps the cooling water circulating in the high-temperature circuit 4. In this embodiment, the second pump 41 is an electric water pump similar to the first pump 31. In particular, in this embodiment, the second pump 41 is provided in the condenser outflow passage 4b1. Also, the high-temperature radiator 44 is a heat exchanger that performs heat exchange between the cooling water circulating in the high-temperature circuit 4 and the outside air, similar to the low-temperature radiator 32.

[0050] The heater core 42 is used to heat the passenger compartment by utilizing the heat of the cooling water in the high-temperature circuit 4. That is, the heater core 42 is configured to perform heat exchange between the cooling water circulating in the high-temperature circuit 4 and the air around the heater core 42 to warm the air around the heater core 42, and as a result, heat the passenger compartment. Specifically, the heater core 42 is configured to exhaust heat from the cooling water to the air around the heater core 42. Therefore, when high-temperature cooling water flows through the heater core 42, the temperature of the cooling water decreases, and at the same time, the air around the heater core 42 is warmed.

[0051] A third pump 51 is provided in the engine inflow passage 4b3. The third pump 51 pumps the cooling water to the engine heat exchanger 43. In the present embodiment, the third pump 51 is an electric water pump similar to the first pump 31.

[0052] A third electromagnetic control valve 52 is provided in the first communication passage 4a. Also, a fourth electromagnetic control valve 54 is provided in the capacitor inflow passage 4a1, and a fifth electromagnetic control valve 56 is provided in the core inflow passage 4a4.

[0053] The engine heat exchanger 43 is used to release the heat generated in the internal combustion engine 110 and is used to heat the cooling water by utilizing the exhaust heat of the internal combustion engine 110. That is, the engine heat exchanger 43 exhausts the exhaust heat from the internal combustion engine 110 to the cooling water in the high-temperature circuit 4 to heat the cooling water. The engine heat exchanger 43 suppresses the excessive temperature rise of the internal combustion engine 110 by discharging the heat generated by the combustion of the fuel in the internal combustion engine 110 to the cooling water. The engine heat exchanger 43 is composed of, for example, the cooling water passages provided in the cylinder block and cylinder head of the internal combustion engine 110.

[0054] The thermostat 46 is a valve that can be switched between a closed valve state that controls the flow of cooling water through the high-temperature radiator outlet passage 4b2 and shuts off the flow of cooling water through the high-temperature radiator 44, and an open valve state that permits the flow of cooling water through the high-temperature radiator 44. When the temperature of the cooling water circulating through the engine inlet passage 4b3 is equal to or higher than a preset temperature, the thermostat 46 opens to allow the cooling water to flow through the high-temperature radiator 44. On the other hand, when the temperature of the cooling water circulating through the engine inlet passage 4b3 is lower than the preset temperature, the thermostat 46 closes to prevent the cooling water from flowing through the high-temperature radiator 44. As a result, the temperature of the cooling water flowing through the engine heat exchanger 43 is kept substantially constant.

[0055] <<Air passage>> FIG. 3 is a configuration diagram schematically showing the air passage 7 for air conditioning of the vehicle 100 equipped with the in-vehicle temperature control system 1. In the air passage 7, air flows in the direction indicated by the arrow in the figure. The air passage 7 shown in FIG. 3 is connected to the outside of the vehicle 100 or the air intake of the passenger compartment, and outside air or air inside the passenger compartment flows into the air passage 7 according to the control state by the control device 6. Further, the air passage 7 shown in FIG. 3 is connected to a plurality of air outlets that blow air into the passenger compartment, and air is supplied from the air passage 7 to any of these air outlets according to the control state by the control device 6.

[0056] As shown in FIG. 3, in the air passage 7 for air conditioning of the present embodiment, a blower 71, an evaporator 26, an air mix door 72, and a heater core 42 are provided in this order in the air flow direction.

[0057] The blower 71 includes a blower motor 71a and a blower fan 71b. When the blower fan 71b is driven by the blower motor 71a, the blower 71 is configured such that outside air or air inside the passenger compartment flows into the air passage 7 and air flows through the air passage 7. When heating or cooling of the passenger compartment is required, the blower fan 71b is basically driven.

[0058] The air mix door 72 adjusts the flow rate of the air flowing through the air passage 7 that passes through the heater core 42. The air mix door 72 is configured to be adjustable between a state in which all the air flowing through the air passage 7 passes through the heater core 42, a state in which all the air flowing through the air passage 7 does not pass through the heater core 42, and an intermediate state therebetween.

[0059] In the air passage 7 configured as described above, when the blower 71 is driven and the refrigerant is circulated through the evaporator 26, the air flowing through the air passage 7 is cooled. Also, when the blower 71 is driven and the cooling water is circulated through the heater core 42 and the air mix door 72 is controlled so that the air passes through the heater core 42, the air flowing through the air passage 7 is warmed.

[0060] Also, as shown in FIG. 1, the low-temperature radiator 32 and the high-temperature radiator 44 are arranged inside the front grille of the vehicle 100. Therefore, when the vehicle 100 is running, the running wind hits these radiators 32, 44. Also, a fan 76 is provided adjacent to these radiators 32, 44. The fan 76 is configured such that when it is driven, wind hits the radiators 32, 44. Therefore, even when the vehicle 100 is not running, by driving the fan 76, wind can be applied to the radiators 32, 44.

[0061] <<Control Device>> Referring to FIG. 2, the control device 6 has an electronic control unit (ECU) 61. The ECU 61 includes a processor that performs various calculations, a memory that stores programs and various information, and an interface that is connected to various actuators and various sensors.

[0062] In addition, the control device 6 includes sensors such as a water temperature sensor (1) 62 that detects the water temperature of the cooling water in the water-cooled condenser 22 (in the cooling water pipe 22b), a water temperature sensor (2) 63 that detects the water temperature of the cooling water at the outlet of the engine heat exchanger 43 (in the engine outflow passage 4a3), and a battery temperature sensor 64 that detects the temperature of the battery 120. The ECU 61 is connected to these sensors, and output signals from these sensors are input to the ECU 61. Instead of detecting the water temperature of the cooling water in the cooling water pipe 22b, the water temperature sensor 62 may detect the water temperature of at least one of the condenser inflow passage 4a1 and the condenser outflow passage 4b1.

[0063] In addition, the control device 6 includes an in-vehicle temperature sensor 66 that detects the temperature inside the vehicle 100, an outside air temperature sensor 67 that detects the temperature outside the vehicle 100, and an operation panel 68 that is operated by the user. The ECU 61 is connected to these sensors and the operation panel 68, and output signals from these sensors and the operation panel 68 are input to the ECU 61.

[0064] Based on the water temperature of the cooling water in the high-temperature circuit 4, the ECU 61 controls the flow of the cooling water to the water-cooled condenser 22. Also, based on the output signal from the battery temperature sensor 64, the ECU 61 determines whether there is a battery cooling requirement. For example, when the temperature of the battery 120 detected by the battery temperature sensor 64 is equal to or higher than a predetermined value, the ECU 61 determines that battery cooling is required.

[0065] The ECU 61 determines the presence or absence of an air conditioning request (cooling request or heating request) based on the output signals from the sensors 66, 67 and the operation panel 68. For example, when the user turns on the heating switch of the operation panel 68, the ECU 61 determines that heating is requested. Also, when the user turns on the auto switch of the operation panel 68, for example, when the indoor temperature set by the user is higher than the temperature detected by the indoor temperature sensor 66, the ECU 61 determines that heating is requested. Further, when the user turns on the auto switch of the operation panel 68, for example, when the indoor temperature set by the user is lower than the temperature detected by the indoor temperature sensor 66, the ECU 61 determines that cooling is requested.

[0066] In addition, the ECU 61 is connected to various actuators of the in-vehicle temperature control system 1 and controls these actuators. Specifically, the ECU 61 is connected to the compressor 21, the electromagnetic control valves 28, 29, 52, 54, 56, the pumps 31, 41, 51, the three-way valves 33, 34, the blower motor 71a, the air mix door 72 and the fan 76 and controls them. Therefore, the ECU 61 functions as a control device that controls the flow state of the heat transfer media (refrigerant and cooling water) in the refrigeration circuit 2, the low-temperature circuit 3 and the high-temperature circuit 4.

[0067] <Operation of the In-vehicle Temperature Control System> Next, the operation of the in-vehicle temperature control system 1 configured as described above will be described.

[0068] ≪Intermittent Water Flow of the Water-cooled Condenser≫ In the in-vehicle temperature control system 1, when the internal combustion engine 110 is operating and no air conditioning request or battery cooling request is issued, heat exchange does not occur between the high-temperature circuit 4 and the refrigeration circuit 2. For this reason, the flow of the cooling water in the cooling water pipe 22b of the water-cooled condenser 22 is stopped. High-temperature cooling water circulates through the engine heat exchanger 43 and the heater core 42. At this time, since the cooling water of the high-temperature circuit 4 does not flow into the water-cooled condenser 22, the cooling water in the water-cooled condenser 22 becomes low temperature (for example, normal temperature of about 20°C).

[0069] When an air conditioning request or a battery cooling request is issued in this state, heat exchange is performed between the high-temperature circuit 4 and the refrigeration circuit 2. Specifically, by flowing cooling water through the cooling water pipe 22b of the water-cooled condenser 22, heat is dissipated from the refrigerant flowing through the refrigeration circuit 2 to the cooling water flowing through the cooling water pipe 22b of the high-temperature circuit 4, and the cooling water of the high-temperature circuit 4 is heated. When a heating request is issued, heating in the vehicle interior is performed by flowing the heated cooling water through the heater core 42. When a cooling request is issued, the evaporator 26 absorbs heat from the air around the evaporator 26 into the refrigerant, so that the air around the evaporator 26 is cooled, and cooling in the vehicle interior is performed.

[0070] When a battery cooling request is issued, by flowing cooling water through the cooling water pipe 22b of the water-cooled condenser 22, the heat of the low-temperature circuit 3 absorbed by the refrigerant of the refrigeration circuit 2 via the chiller 27 is dissipated to the cooling water flowing through the cooling water pipe 22b of the high-temperature circuit 4, and the cooling water of the low-temperature circuit 3 is cooled.

[0071] When an air conditioning request or a battery cooling request is issued, if the temperature of the cooling water in the water-cooled condenser 22 is decreasing, when cooling water is flowed through the water-cooled condenser 22, the low-temperature cooling water in the water-cooled condenser 22 flows into the internal combustion engine 110 or the heater core 42 after warm-up, and the high-temperature cooling water discharged from the engine heat exchanger 43 flows into the cooled water-cooled condenser 22. For this reason, the temperature of the internal combustion engine 110 or the heater core 42 drops rapidly, and the temperature of the water-cooled condenser 22 rises rapidly. As a result, heat loads are applied to devices such as the internal combustion engine 110, the heater core 42, and the water-cooled condenser 22, and there is a possibility that thermal distortion occurs in these devices.

[0072] When a heating request is issued with the cooling water in the water-cooled condenser 22 cooled, it takes time for warm air to come out of the warm air outlet in the vehicle interior because the low-temperature cooling water in the water-cooled condenser 22 flows into the heater core 42, which may give a sense of discomfort to the vehicle occupants.

[0073] On the other hand, when there is a battery cooling requirement or a cooling requirement, since the water-cooled condenser 22 being cooler improves the efficiency of battery cooling and cooling, it is not preferable to raise the temperature of the water-cooled condenser 22 more than necessary. Specifically, when the water temperature of the cooling water in the water-cooled condenser 22 becomes too high, the amount of heat that the cooling water in the high-temperature circuit 4 can absorb by heat absorption decreases. Therefore, when there is a battery cooling requirement or a cooling requirement, the battery cooling capacity or the cooling capacity may decrease, and situations such as the battery 120 overheating or the passenger compartment not being cooled to the desired temperature may occur.

[0074] Therefore, in this embodiment, when there is no air conditioning requirement or battery cooling requirement, in order to preliminarily bring the water-cooled condenser 22 into the optimal temperature range, the cooling water is intermittently passed through the water-cooled condenser 22 by the flow rate variable device.

[0075] FIG. 4 is a timing chart showing, in order from the top, the internal water temperature of the internal combustion engine 110, the state of the air conditioning request flag indicating the air conditioning request by the user, the state of the battery cooling request flag indicating the battery cooling request, the water temperature at the inlet side of the heater core 42, the water temperature of the cooling water in the water-cooled condenser 22, the flow rate of the cooling water flowing through the engine heat exchanger 43, the flow rate of the cooling water flowing through the heater core 42, and the flow rate of the cooling water flowing through the water-cooled condenser 22. FIG. 3 shows the change of each value after the internal combustion engine 110 is started at time t0. Note that the internal water temperature of the internal combustion engine 110 is the water temperature of the cooling water in the engine heat exchanger 43. Also, the water temperature at the inlet side of the heater core 42 is the water temperature of the cooling water in the core inflow passage 4a4 on the inlet side of the heater core 42, and is equivalent to the water temperature of the cooling water in the engine outflow passage 4a3 on the outlet side of the engine heat exchanger 43.

[0076] Figure 4 shows a case where no air conditioning request has been made by the user and no battery cooling request has been made, and the states of the air conditioning request flag and the battery cooling request flag are Low. When the internal combustion engine 110 starts at time t0, the driving of the second pump 41 and the third pump 51 is set to off until time t1. Also, the third electromagnetic control valve 52, the fourth electromagnetic control valve 54, and the fifth electromagnetic control valve 56 are opened. Figure 5 is a diagram showing the state of the cooling water in the high-temperature circuit 4 from time 0 to time t1. In Figure 5, the passage indicated by the broken line shows a state where the flow of the cooling water has stopped, and the same applies to Figures 6, 7, 10, 11, and 12 described later. As shown in Figure 5, from time t0 immediately after the start of the internal combustion engine 110 to time t1, the flow of the cooling water stops in all passages in the high-temperature circuit 4.

[0077] When the internal combustion engine 110 starts at time 0, the internal water temperature of the internal combustion engine 110 rises with the passage of time. Also, from time 0 to time t1, since the flow of the cooling water in the high-temperature circuit 4 has stopped, the water temperature at the inlet side of the heater core 42 and the water temperature of the cooling water in the water-cooled condenser 22 do not change.

[0078] Also, from time 0 to time t1, due to the stoppage of the flow of the cooling water in the high-temperature circuit 4, the flow rate of the cooling water flowing through the engine heat exchanger 43, the flow rate of the cooling water flowing through the heater core 42, and the flow rate of the cooling water flowing through the water-cooled condenser 22 are 0.

[0079] When the internal water temperature of the internal combustion engine 110 reaches a predetermined value at time t1, the drive of the third pump 51 is turned on to start cooling the internal combustion engine 110. The drive of the second pump 41 is maintained off. The third electromagnetic control valve 52, the fourth electromagnetic control valve 54, and the fifth electromagnetic control valve 56 are maintained in the open state. FIG. 6 is a diagram showing the flow of cooling water in the high-temperature circuit 4 after the drive of the third pump 51 is turned on at time t1. In FIG. 6, the flow of cooling water is indicated by arrows. As shown in FIG. 6, when the drive of the third pump 51 is turned on at time t1, the cooling water flows through the engine heat exchanger 43, and the cooling water discharged from the engine heat exchanger 43 flows into the heater core 42 and the water-cooled condenser 22. Note that the thermostat 46 opens according to the temperature of the cooling water circulating through the engine inlet passage 4b3, and cooling water flows into the high-temperature radiator 44. However, since FIG. 4 shows immediately after the start of the internal combustion engine 110, almost no cooling water flows into the high-temperature radiator 44 during this period. Note that the internal water temperature of the internal combustion engine 110 reaches a steady state (about 90 ° C) at time t8.

[0080] After time t1, the internal water temperature of the internal combustion engine 110 also rises with the passage of time. In addition, as the cooling water discharged from the engine heat exchanger 43 flows into the heater core 42 and the water-cooled condenser 22, the water temperature on the inlet side of the heater core 42 and the water temperature of the cooling water in the water-cooled condenser 22 rise with the passage of time.

[0081] In addition, as the cooling water discharged from the engine heat exchanger 43 flows into the heater core 42 and the water-cooled condenser 22 after time t1, the flow rate of the cooling water flowing through the engine heat exchanger 43, the flow rate of the cooling water flowing through the heater core 42, and the flow rate of the cooling water flowing through the water-cooled condenser 22 increase with the passage of time and reach a steady state at time t2 respectively. Note that the flow rate of the cooling water flowing through the engine heat exchanger 43 is the sum of the flow rate of the cooling water flowing through the heater core 42 and the flow rate of the cooling water flowing through the water-cooled condenser 22.

[0082] At time t2, the water temperature on the inlet side of the heater core 42 reaches the internal water temperature of the internal combustion engine 110, and thereafter changes in the same manner as the internal water temperature of the internal combustion engine 110. Similarly, the water temperature of the cooling water in the water-cooled condenser 22 reaches the internal water temperature of the internal combustion engine 110 at time t2, and if the cooling water is not intermittently passed through the water-cooled condenser 22, it will change in the same manner as the internal water temperature of the internal combustion engine 110 thereafter. Note that in the characteristics of the water temperature on the inlet side of the heater core 42 and the water temperature of the cooling water in the water-cooled condenser 22 in FIG. 4, the internal water temperature of the internal combustion engine 110 is indicated by a broken line.

[0083] In this way, when there is no air conditioning request or battery cooling request, by flowing the cooling water discharged from the engine heat exchanger 43 into the water-cooled condenser 22, the temperature of the cooling water in the water-cooled condenser 22 rises.

[0084] In the present embodiment, a specified lower limit temperature and a specified upper limit temperature are set for the water temperature of the cooling water in the water-cooled condenser 22. When the water temperature of the cooling water in the water-cooled condenser 22 increases in the same manner as the internal water temperature of the internal combustion engine 110 after time t2, the water temperature of the cooling water in the water-cooled condenser 22 reaches the specified upper limit temperature at time t3. In the present embodiment, by intermittently passing water through the water-cooled condenser 22, the water temperature of the cooling water in the water-cooled condenser 22 is controlled to fall within the range between the specified lower limit temperature and the specified upper limit temperature. When the temperature of the cooling water in the water-cooled condenser 22 detected by the water temperature sensor 62 reaches a predetermined upper limit temperature (specified upper limit temperature), the ECU 61 stops the inflow of the cooling water into the water-cooled condenser 22, and when the temperature of the cooling water in the water-cooled condenser 22 reaches a predetermined lower limit temperature (specified lower limit temperature), the ECU 61 controls the fourth electromagnetic regulating valve 54 to allow the cooling water to flow into the water-cooled condenser 22.

[0085] Specifically, when the water temperature of the cooling water in the water-cooled condenser 22 reaches the specified upper limit temperature at time t3, the fourth electromagnetic control valve 54 is closed to suppress the water temperature of the cooling water in the water-cooled condenser 22 below the specified upper limit temperature. The third electromagnetic control valve 52 and the fifth electromagnetic control valve 56 are maintained in the open state. Also, the drive of the third pump 51 is maintained in the on state, and the drive of the second pump 41 is maintained off. FIG. 7 is a diagram showing the flow of the cooling water in the high-temperature circuit 4 after the fourth electromagnetic control valve 54 is closed at time t3. As shown in FIG. 7, when the fourth electromagnetic control valve 54 is closed at time t3, the cooling water discharged from the engine heat exchanger 43 does not flow into the water-cooled condenser 22. Thereby, the water temperature of the cooling water in the water-cooled condenser 22 decreases and is suppressed below the specified upper limit temperature.

[0086] When the water temperature of the cooling water in the water-cooled condenser 22 decreases due to closing the fourth electromagnetic control valve 54 and reaches the specified lower limit temperature in the water-cooled condenser 22 at time t4, the fourth electromagnetic control valve 54 is opened. The third electromagnetic control valve 52 and the fifth electromagnetic control valve 56 are maintained in the open state. Also, the drive of the third pump 51 is maintained in the on state, and the drive of the second pump 41 is maintained off. The flow of the cooling water in the high-temperature circuit 4 is the same as in FIG. 6, and the cooling water discharged from the engine heat exchanger 43 flows into the heater core 42 and the water-cooled condenser 22. Thereby, since the cooling water discharged from the engine heat exchanger 43 flows into the water-cooled condenser 22, the water temperature of the cooling water in the water-cooled condenser 22 rises and becomes above the specified lower limit temperature.

[0087] Similarly, after time t4, the fourth electromagnetic control valve 54 is opened and closed based on the water temperature of the cooling water in the water-cooled condenser 22, and intermittent water flow to the water-cooled condenser 22 is performed. Thereby, the water temperature of the cooling water in the water-cooled condenser 22 is controlled to be within the range between the specified lower limit temperature and the specified upper limit temperature. If intermittent water flow is not performed after time t3, as shown by the dashed line in FIG. 4, the water temperature of the cooling water in the water-cooled condenser 22 rises in the same manner as the internal water temperature of the internal combustion engine 110.

[0088] Hereinafter, with reference to FIG. 8, the switching control of the fourth electromagnetic control valve 54 by the ECU 61 will be described. FIG. 8 is a flowchart showing the flow of the switching process of the fourth electromagnetic control valve 54 by the ECU 61. The illustrated switching process is executed at regular time intervals. It is assumed that the drive of the third pump 51 is on and the drive of the second pump 41 is off at the start of the process.

[0089] First, the ECU 61 determines whether the mode of performing intermittent water flow to the water-cooled capacitor 22 is on (ON) (step S10). If the mode of performing intermittent water flow is on, it determines whether there is no air-conditioning request (step S12).

[0090] If there is no air-conditioning request in step S12, the ECU 61 determines whether there is no battery cooling request (step S14). If there is no battery cooling request, it determines whether the fourth electromagnetic control valve 54 is closed (step S16).

[0091] If the fourth electromagnetic control valve 54 is closed in step S16, the ECU 61 determines whether the water temperature of the cooling water in the water-cooled capacitor 22 has reached the specified lower limit temperature (step S18). If the water temperature has reached the specified lower limit temperature, it controls to open the fourth electromagnetic control valve 54 (step S20). Thereby, the water temperature of the cooling water in the water-cooled capacitor 22 is controlled to be equal to or higher than the specified lower limit temperature.

[0092] If the fourth electromagnetic control valve 54 is open in step S16, the ECU 61 determines whether the water temperature of the cooling water in the water-cooled capacitor 22 has reached the specified upper limit temperature (step S22). If the water temperature has reached the specified upper limit temperature, it controls to close the fourth electromagnetic control valve 54 (step S24). Thereby, the water temperature of the cooling water in the water-cooled capacitor 22 is controlled to be equal to or lower than the specified upper limit temperature.

[0093] When there is an air conditioning request in step S12 or a battery cooling request in step S14, the ECU 61 performs control to open the fourth electromagnetic control valve 54 (step S20). Also, in this case, the compressor 21 of the refrigeration circuit 2 is driven. Thereby, heat exchange is performed between the high-temperature circuit 4 and the refrigeration circuit 2.

[0094] If the mode of performing intermittent water flow in step S10 is off, the ECU 61 determines whether the water temperature of the cooling water in the water-cooled condenser 22 is equal to or higher than a specified upper limit temperature (step S26). If the water temperature is equal to or higher than the specified upper limit temperature, the mode of performing intermittent water flow is set to on (step S28).

[0095] According to the process of FIG. 8, in a state where no air conditioning request or battery cooling request is issued, control is performed so that the water temperature of the cooling water in the water-cooled condenser 22 falls within a range between a specified lower limit temperature and a specified upper limit temperature. Therefore, when an air conditioning request or a battery cooling request is issued, the low-temperature cooling water in the water-cooled condenser 22 does not flow into the internal combustion engine 110 after warm-up or the heater core 42, and the heat load on the internal combustion engine 110 or the heater core 42 is suppressed, and thermal distortion in these devices is suppressed from occurring. Also, since the high-temperature cooling water discharged from the engine heat exchanger 43 does not flow into the water-cooled condenser 22 in a state where the temperature of the water-cooled condenser 22 has decreased, the heat load on the water-cooled condenser 22 is suppressed, and thermal distortion in the water-cooled condenser 22 is suppressed from occurring.

[0096] Also, when an air conditioning request is issued, the low-temperature cooling water in the water-cooled condenser 22 does not flow into the heater core 42, and the cooling water at or above the specified lower limit temperature flows into the heater core 42. Therefore, it does not take time for warm air to come out from the warm air outlet in the vehicle interior, and it is suppressed that the vehicle occupants feel discomfort. Furthermore, since the temperature of the water-cooled condenser 22 does not rise more than necessary, it is suppressed that the efficiency during battery cooling and air conditioning decreases.

[0097] ≪When a stop request for the internal combustion engine≫ Next, the control when a stop request for the internal combustion engine 110 is issued will be described. When a stop request for the internal combustion engine 110 is issued during the operation of the vehicle 100 and the internal combustion engine 110 stops (idling stop state), the vehicle 100 is driven by the MG112. When there is no air conditioning request or battery cooling request, heat exchange does not occur between the high-temperature circuit 4 and the refrigeration circuit 2, so cooling water does not flow through the water-cooled condenser 22, and the cooling water in the water-cooled condenser 22 becomes low temperature (for example, normal temperature of about 20°C).

[0098] When an air conditioning request is issued with the internal combustion engine 110 stopped, the second pump 41 is driven, the third electromagnetic control valve 52 is closed, and the fourth electromagnetic control valve 54 and the fifth electromagnetic control valve 56 are opened, so that cooling water circulates between the water-cooled condenser 22 and the heater core 42. Also, the compressor 21 is driven, and heat exchange occurs between the high-temperature circuit 4 and the refrigeration circuit 2. Thereby, when a heating request is issued, the heater core 42 is heated to heat the vehicle interior. Also, when a cooling request is issued, heat is absorbed from the air around the evaporator 26 into the refrigerant to cool the vehicle interior, and the cooling water in the high-temperature circuit 4 is heated. Similarly, when a battery cooling request is issued, the heat of the low-temperature circuit 3 absorbed by the refrigerant of the refrigeration circuit 2 via the chiller 27 is radiated to the cooling water flowing through the cooling water pipe 22b of the high-temperature circuit 4, so that the cooling water of the low-temperature circuit 3 is cooled and the cooling water of the high-temperature circuit 4 is heated. The refrigeration circuit 2 functions as a heat pump that pumps heat by absorbing heat into the refrigerant from the evaporator 26 or the chiller 27 and radiates heat from the refrigerant to the cooling water of the high-temperature circuit 4. When the internal combustion engine 110 stops, the cooling water flowing through the heater core 42 is warmed by the function of this heat pump.

[0099] Even when the internal combustion engine 110 stops, the temperature of the heater core 42 may be high due to the high-temperature cooling water discharged from the engine heat exchanger 43 before the stop of the internal combustion engine 110. When an air conditioning request or a battery cooling request is issued in this state, if the temperature of the cooling water in the water-cooled condenser 22 is decreasing, when circulating the cooling water between the water-cooled condenser 22 and the heater core 42, the low-temperature cooling water in the water-cooled condenser 22 flows into the heater core 42, and the high-temperature cooling water discharged from the heater core 42 flows into the cooled water-cooled condenser 22. For this reason, the temperature of the heater core 42 drops rapidly, and the temperature of the water-cooled condenser 22 rises rapidly. As a result, a thermal load is applied to devices such as the heater core 42 and the water-cooled condenser 22, and thermal distortion may occur in these devices.

[0100] Also, particularly when a heating request is issued, it takes a corresponding amount of time for the heat pump to draw up the desired heat from the evaporator 26 or the chiller 27. For this reason, if the temperature of the cooling water in the water-cooled condenser 22 is decreasing when the internal combustion engine 110 stops, when circulating the cooling water between the water-cooled condenser 22 and the heater core 42, the low-temperature cooling water in the water-cooled condenser 22 flows into the heater core 42, and the temperature of the heater core 42 may drop until heat is drawn up by the heat pump. Then, when the water temperature of the cooling water in the heater core 42 (the water temperature of the cooling water in the water-cooled condenser 22) becomes lower than the heater required temperature necessary for heating the passenger compartment, heating of the passenger compartment cannot be performed. In this case, it becomes necessary to restart the internal combustion engine 110 to supply warm cooling water to the heater core 42, or it becomes necessary to rotate the compressor 21 at a higher speed to draw up heat in a shorter time. As a result, fuel consumption deterioration and NV deterioration are caused. Also, restarting the internal combustion engine 110 may give the driver a sense of discomfort.

[0101] Therefore, in this embodiment, when a stop request for the internal combustion engine 110 is issued while no air conditioning request or battery cooling request is issued, cooling water is passed through the water-cooled condenser 22, and when the temperature of the cooling water in the water-cooled condenser 22 reaches a predetermined temperature, the internal combustion engine 110 is stopped. When stopping the internal combustion engine 110 during vehicle operation, the ECU 61 controls the fourth electromagnetic regulating valve 54 so that the cooling water flows into the water-cooled condenser 22, and stops the internal combustion engine 110 after raising the temperature of the cooling water in the water-cooled condenser 22. The ECU 61 may stop the internal combustion engine 110 after flowing the cooling water into the water-cooled condenser 22 until the temperature of the cooling water in the water-cooled condenser 22 detected by the water temperature sensor 62 reaches a specified temperature 1 described later, or until it is estimated that the temperature of the cooling water in the high-temperature circuit 4 reaches a specified temperature 2 described later.

[0102] FIG. 9 is a timing chart showing, in order from the top, the water temperature at the outlet side of the engine heat exchanger 43, the state of the heating request flag indicating the heating request by the user, the state of the start request flag of the internal combustion engine 110, the blower rotation speed, the rotation speed of the compressor 21, the amount of heat transferred by the heat pump to the water-cooled condenser 22, the water temperature of the cooling water in the heater core 42, the water temperature of the cooling water in the water-cooled condenser 22, the flow rate of the cooling water flowing through the engine heat exchanger 43, the flow rate of the cooling water flowing through the heater core 42, and the flow rate of the cooling water flowing through the water-cooled condenser 22. The blower rotation speed is the rotation speed of the blower motor 71a.

[0103] As shown in FIG. 9, between time t10 and time t12, the internal combustion engine 110 is operating, and the water temperature at the outlet side of the engine heat exchanger 43 is about 90°C. In this state, the warm-up of the internal combustion engine 110 is completed.

[0104] Figure 9 shows a case where no battery cooling requirement is issued. Similar to Figure 3, the state of the battery cooling requirement flag (not shown in Figure 9) is always Low. On the other hand, regarding the user's heating requirement, at time t10, the state of the heating requirement flag is Low, but at time t13, the user issues a heating requirement, and at time t13, the state of the heating requirement flag switches from Low to High. Therefore, between time t10 and time t13, the blower motor 71a and the compressor 21 are stopped, and the blower rotation speed and the compressor rotation speed are 0.

[0105] Also, at time t10, the drive of the third pump 51 is turned ON, and the drive of the second pump 41 is turned OFF. Also, at time t10, the third electromagnetic control valve 52 and the fifth electromagnetic control valve 56 are opened, and the fourth electromagnetic control valve 54 is closed. This state is maintained until t11 when a stop request for the internal combustion engine 110 is issued.

[0106] Figure 10 is a diagram showing the flow of cooling water in the high-temperature circuit 4 between time 10 and time t11. As shown in Figure 10, when the drive of the third pump 51 is turned ON, cooling water flows into the engine heat exchanger 43. Also, when the third electromagnetic control valve 52 and the fifth electromagnetic control valve 56 are opened and the fourth electromagnetic control valve 54 is closed, the cooling water discharged from the engine heat exchanger 43 flows into the heater core 42 and the high-temperature radiator 44 and does not flow into the water-cooled condenser 22. Note that the thermostat 46 is opened according to the temperature of the cooling water circulating through the engine inflow passage 4b3, and cooling water appropriately flows into the high-temperature radiator 44.

[0107] Therefore, as shown in Figure 9, between time 10 and time t11, a predetermined amount of cooling water flows through the engine heat exchanger 43, and a predetermined amount of cooling water also flows through the heater core 42. On the other hand, between time 10 and time t11, the flow rate of the cooling water flowing through the water-cooled condenser 22 is 0. Since no cooling water flows through the water-cooled condenser 22, the water temperature of the cooling water in the water-cooled condenser 22 gradually decreases.

[0108] When a stop request for the internal combustion engine 110 is issued at time t11, the state of the start request flag of the internal combustion engine 110 switches from High to Low. When the state of the start request flag switches from High to Low, since the water temperature of the cooling water in the water-cooled condenser 22 detected by the water temperature sensor 62 is lower than the specified temperature 1 (for example, 80°C), the fourth electromagnetic control valve 54 is opened. The third electromagnetic control valve 52 and the fifth electromagnetic control valve 56 are maintained in the open state. Also, the driving of the third pump 51 is maintained in the on state, and the driving of the second pump 41 is maintained off.

[0109] FIG. 11 is a diagram showing the flow of the cooling water in the high-temperature circuit 4 after the fourth electromagnetic control valve 54 is opened at time t11. As shown in FIG. 11, when the fourth electromagnetic control valve 54 is opened at time t11, the cooling water discharged from the engine heat exchanger 43 flows into the water-cooled condenser 22, and water passes through the water-cooled condenser 22. As a result, as shown in FIG. 9, the flow rate of the cooling water flowing through the water-cooled condenser 22 increases, and the water temperature of the cooling water in the water-cooled condenser 22 rises after time t11. The cooling water discharged from the engine heat exchanger 43 continues to flow into the heater core 42 as well, but since a part of the cooling water discharged from the engine heat exchanger 43 flows into the water-cooled condenser 22, the flow rate of the cooling water flowing through the heater core 42 becomes less than before time t11.

[0110] When the water temperature of the cooling water in the water-cooled condenser 22 reaches the specified temperature 1 at time t12, the internal combustion engine 110 is stopped in response to the stop request at time t11. In this case, since the water temperature of the cooling water in the water-cooled condenser 22 has reached the specified temperature 1, although the cooling water in the path may not have reached the specified temperature 1 throughout the path, it is considered that the temperature of the cooling water in the path has risen to at least a predetermined temperature (for example, about 70°C) higher than the specified temperature 1 throughout the path, so the internal combustion engine 110 is stopped.

[0111] In addition, after the water temperature of the cooling water in the water-cooled condenser 22 reaches a specified temperature 2 (for example, about 70°C) lower than the specified temperature 1, when a predetermined time has elapsed, the internal combustion engine 110 may be stopped in response to a stop request at time t11. In this case, since it is estimated that the cooling water in the path has been heated to the specified temperature 2 as a whole, the internal combustion engine 110 is stopped.

[0112] Note that the specified temperature 1 and the specified temperature 2 are determined based on the outlet water temperature of the engine heat exchanger 43 detected by the water temperature sensor 63, and are set to values lower than the outlet water temperature. For example, if the outlet water temperature of the engine heat exchanger 43 is T, the specified temperature 1 = T - α, and the specified temperature 2 = T - β. However, α and β are constants that satisfy the relationship α < β.

[0113] As described above, when the inside of the cooling water path as a whole reaches a predetermined temperature (about 70°C in the above example), the internal combustion engine 110 is stopped in response to a stop request.

[0114] As described above, after the stop request for the internal combustion engine 110 is issued at time t11, water is passed through the water-cooled condenser 22, and when the water temperature of the cooling water in the water-cooled condenser 22 reaches a desired temperature, the internal combustion engine 110 is stopped. Therefore, the water temperature of the cooling water in the water-cooled condenser 22 can be raised in advance before the internal combustion engine 110 stops.

[0115] When the internal combustion engine 110 stops at time t12, the drive of the third pump 51 is turned off. The drive of the second pump 41 is maintained off. Also, the third electromagnetic control valve 52, the fourth electromagnetic control valve 54, and the fifth electromagnetic control valve 56 are maintained in the open state. Therefore, the flow of the cooling water in the high-temperature circuit 4 stops. Note that this state is the same as in FIG. 5. As a result, as shown in FIG. 9, the flow rate of the cooling water flowing through the engine heat exchanger 43, the flow rate of the cooling water flowing through the heater core 42, and the flow rate of the cooling water flowing through the water-cooled condenser 22 become zero. When the flow of the cooling water in the high-temperature circuit 4 stops with the internal combustion engine 110 stopped, the water temperature of the cooling water in the heater core 42 and the water temperature of the cooling water in the water-cooled condenser 22 gradually decrease.

[0116] When a heating request is issued by the user at time t13 and the state of the heating request flag switches from Low to High, the drive of the second pump 41 is turned on. The drive of the third pump 51 remains off. Also, the third electromagnetic control valve 52 is closed. The fourth electromagnetic control valve 54 and the fifth electromagnetic control valve 56 remain in the open state.

[0117] Also, when the state of the heating request flag switches from Low to High at time t13, the blower motor 71a is driven and the blower rotation speed increases. Also, when the state of the heating request flag switches from Low to High at time t13, the compressor 21 is driven and the compressor rotation speed increases. Thereby, heating by the heat pump is started with the internal combustion engine 110 stopped.

[0118] FIG. 12 is a diagram showing the flow of cooling water in the high-temperature circuit 4 after the drive of the second pump 41 is turned on and the third electromagnetic control valve 52 is closed at time t13. As shown in FIG. 12, when the drive of the second pump 41 is turned on and the third electromagnetic control valve 52 is closed, cooling water flows into the water-cooled condenser 22 by the drive of the second pump 41, and the cooling water discharged from the water-cooled condenser 22 flows into the heater core 42, so that cooling water circulates between the water-cooled condenser 22 and the heater core 42. Therefore, as shown in FIG. 9, the flow rate of the cooling water flowing through the heater core 42 increases. Also, since the cooling water flows in the opposite direction to that in FIG. 11 through the water-cooled condenser 22, the flow rate of the cooling water flowing through the water-cooled condenser 22 becomes a negative value and the absolute value thereof increases.

[0119] When the compressor 21 is driven at time t13, refrigerant flows into the water-cooled condenser 22. Thereby, the water-cooled condenser 22 dissipates heat from the refrigerant in the refrigeration circuit 2 to the cooling water in the high-temperature circuit 4, so that as shown in FIG. 9, the amount of heat transferred by the heat pump of the water-cooled condenser 22 gradually increases, and the amount of heat transferred becomes steady at time t14.

[0120] At this time, since it takes a corresponding amount of time for the heat pump to extract the desired heat from the evaporator 26 or the chiller 27, the amount of heat transferred by the heat pump for the water-cooled condenser 22 does not increase rapidly even when the compressor 21 is driven at time t13, but increases gradually.

[0121] Since the internal combustion engine 110 has stopped after time t12, the water temperature of the cooling water in the heater core 42 decreases. However, since the water temperature of the cooling water in the water-cooled condenser 22 has been raised to a prescribed temperature 1 in advance at time t12, the water-cooled condenser 22 dissipates heat naturally from the state of being at a high temperature. As a result, the shortage of the amount of heat transferred until the amount of heat transferred by the heat pump for the water-cooled condenser 22 reaches the steady state is compensated by the amount of heat of the cooling water in the water-cooled condenser 22 whose temperature has been raised to a high temperature in advance. Therefore, it is possible to compensate for the delay in the start-up of heating until the heat pump capacity of the refrigeration cycle stabilizes. Also, it is suppressed that the water temperature of the cooling water in the heater core 42 becomes lower than the heater required temperature until time t14 when the amount of heat transferred by the heat pump for the water-cooled condenser 22 reaches the steady state, and the restart of the internal combustion engine 110 is avoided. Then, after time t14, since the amount of heat transferred by the heat pump for the water-cooled condenser 22 has reached the steady state, the water temperature of the cooling water in the heater core 42 is maintained at a temperature higher than the heater required temperature by the heat pump. Therefore, heating is stably performed even when the internal combustion engine 110 has stopped.

[0122] After the internal combustion engine 110 stops at time t12, the temperature of the cooling water in the water-cooled condenser 22 gradually decreases. Therefore, if a long time elapses before a heating request is issued, it is assumed that the temperature of the cooling water in the water-cooled condenser 22 may fall below the heater request temperature. Even in this case, since the temperature of the cooling water in the water-cooled condenser 22 reaches the specified temperature 1 at time t12 by passing water through the water-cooled condenser 22, compared with the case where water is not passed through the water-cooled condenser 22, the time until the temperature of the cooling water in the water-cooled condenser 22 falls below the heater request temperature can be made longer. Therefore, the time until the internal combustion engine 110 restarts due to the temperature of the cooling water in the water-cooled condenser 22 falling below the heater request temperature can be made longer, and deterioration of fuel consumption and NV can be reduced.

[0123] Note that as shown in FIG. 9, when the amount of heat transferred by the heat pump of the water-cooled condenser 22 reaches a steady state at time t14, the rotational speed of the compressor 21 is reduced to a lower rotational speed.

[0124] Next, when a start request for the internal combustion engine 110 is issued at time t15, the state of the start request flag switches from Low to High. When the state of the start request flag switches from Low to High, the third electromagnetic control valve 52 is opened. The fourth electromagnetic control valve 54 and the fifth electromagnetic control valve 56 maintain their open states. Also, the drive of the second pump 41 is turned off, and the drive of the third pump 51 is turned on. The flow of the cooling water in the high-temperature circuit 4 is the same as in FIG. 11.

[0125] As a result, the water temperature on the outlet side of the engine heat exchanger 43, the water temperature of the cooling water in the heater core 42, and the water temperature of the cooling water in the water-cooled condenser 22 all increase. The water temperature on the outlet side of the engine heat exchanger 43 temporarily decreases at time t15 due to the inflow of the cooling water whose temperature has decreased due to the heat exchange in the heater core 42 before time t15, and then increases. Also, cooling water flows through the engine heat exchanger 43 and the water-cooled condenser 22. Since the cooling water flows through the water-cooled condenser 22 in the direction opposite to that in FIG. 12, the flow rate of the cooling water flowing through the water-cooled condenser 22 becomes a positive value. The flow rate of the cooling water flowing through the heater core 42 temporarily decreases at time t15 along with the switching operation of the valve, but the value before time t15 is maintained thereafter.

[0126] When the water temperature on the outlet side of the engine heat exchanger 43 reaches a predetermined value T1 (heat pump completion temperature) at time t16, control is performed to reduce the rotational speed of the compressor 21. As a result, the amount of heat transferred by the heat pump to the water-cooled condenser 22 decreases, and heating is performed by the cooling water heated by the heat exchange in the engine heat exchanger 43. Thereafter, when the warm-up of the internal combustion engine 110 is completed at time t17, the water temperature on the outlet side of the engine heat exchanger 43 becomes about 90°C.

[0127] Hereinafter, with reference to FIG. 13, the switching control of the fourth electromagnetic control valve 54 by the ECU 61 will be described. FIG. 13 is a flowchart showing the flow of the switching process of the fourth electromagnetic control valve 54 by the ECU 61. The illustrated switching process is executed at regular time intervals.

[0128] First, the ECU 61 determines whether a stop request for the internal combustion engine 110 has been issued (step S30). If a stop request has been issued, it determines whether the fourth electromagnetic control valve 54 is open (step S32). If a stop request for the internal combustion engine 110 has not been issued in step S30, the processing in this control cycle ends.

[0129] When the fourth electromagnetic control valve 54 is open in step S32, the ECU 61 determines whether the water temperature of the cooling water in the water-cooled capacitor 22 is equal to or higher than a specified temperature 1 (step S34). When the water temperature of the cooling water in the water-cooled capacitor 22 is equal to or higher than the specified temperature 1, the ECU 61 executes control to stop the internal combustion engine 110 (step S36). On the other hand, when the fourth electromagnetic control valve 54 is not open in step S32, the ECU 61 opens the fourth electromagnetic control valve 54 (step S38) and performs the processes after step S34.

[0130] When the water temperature of the cooling water in the water-cooled capacitor 22 is lower than the specified temperature 1 in step S34, the ECU 61 determines whether or not a certain period of time has elapsed since the water temperature of the cooling water in the water-cooled capacitor 22 exceeded a specified temperature 2 (step S40). Then, when a certain period of time has elapsed since the water temperature of the cooling water in the water-cooled capacitor 22 exceeded the specified temperature 2, the ECU 61 executes control to stop the internal combustion engine 110 (step S36). When a certain period of time has not elapsed since the water temperature of the cooling water in the water-cooled capacitor 22 exceeded the specified temperature 2 in step S40, the processing in this control cycle ends.

[0131] According to the process of FIG. 9, when a stop request for the internal combustion engine 110 is issued, if the fourth electromagnetic control valve 54 is closed, the fourth electromagnetic control valve 54 is opened. Then, the internal combustion engine 110 is not stopped until the temperature of the cooling water in the water-cooled condenser 22 reaches the specified temperature 1, and when the temperature of the cooling water in the water-cooled condenser 22 reaches the specified temperature 1, the internal combustion engine 110 is stopped. Or, the internal combustion engine 110 is not stopped until a certain time has elapsed after the temperature of the cooling water in the water-cooled condenser 22 exceeds the specified temperature 2 which is lower than the specified temperature 1, and when the temperature of the cooling water in the water-cooled condenser 22 exceeds the specified temperature 2 and a certain time has elapsed, the internal combustion engine 110 is stopped. Therefore, when a heating request is issued after the internal combustion engine 110 has stopped, it is possible to suppress the temperature of the heater core 42 from falling below the heater required temperature due to the delay in heating by the heat pump, to suppress the restart of the internal combustion engine 110, or to suppress the high-speed rotation drive of the compressor 21. Therefore, it is possible to prevent the driver from feeling discomfort due to the restart of the internal combustion engine 110 or the high-speed rotation drive of the compressor 21, to suppress the deterioration of fuel consumption, and to reduce NV.

Explanation of Signs

[0132] 1 Vehicle-mounted temperature control system 2 Refrigeration circuit 4 High-temperature circuit 22 Water-cooled condenser 26 Evaporator 42 Heater core 43 Engine heat exchanger 54 Fourth electromagnetic control valve 61 ECU 110 Internal combustion engine

Claims

1. A refrigeration circuit capable of circulating the refrigerant through a medium heat exchanger that dissipates heat from the refrigerant to a heat medium and an evaporator that evaporates the refrigerant, a heat circuit capable of circulating the heat medium through a heater core for heating the vehicle interior, the medium heat exchanger, and an engine heat exchanger that heats the heat medium by exhaust heat of an internal combustion engine, the heat circuit having a regulating valve for regulating the flow of the heat medium discharged from the engine heat exchanger into the medium heat exchanger, a control device that controls the regulating valve to stop the flow of the heat medium into the medium heat exchanger when the temperature of the heat medium in the medium heat exchanger reaches a predetermined upper limit temperature and to allow the heat medium to flow into the medium heat exchanger when the temperature reaches a predetermined lower limit temperature, An in-vehicle temperature control system comprising the above.

2. The in-vehicle temperature control system according to claim 1, wherein when stopping the internal combustion engine during vehicle operation, the control device controls the regulating valve to allow the heat medium to flow into the medium heat exchanger, and stops the internal combustion engine after raising the temperature of the heat medium in the medium heat exchanger.

3. The in-vehicle temperature control system according to claim 2, wherein the control device allows the heat medium to flow into the medium heat exchanger until the temperature of the heat medium in the medium heat exchanger reaches a first predetermined temperature or until it is estimated that the temperature of the heat medium in the heat circuit reaches a second predetermined temperature, and then stops the internal combustion engine.

Images