JP2014234094A - Vehicle heat management system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inhibit the unnecessary decrease in the temperature of a heat medium.SOLUTION: A vehicle heat management system includes: an evaporator 14 cooling a heat medium by implementing heat exchange between low-pressure refrigerant of a refrigeration cycle 20 and the heat medium; a first heat medium circuit C1 in which the heat medium cooled by the evaporator 14 circulates; a cooling water heater 15 heating the heat medium by implementing heat exchange between high-pressure refrigerant of the refrigeration cycle 20 and the heat medium; a second heat medium circuit C2 in which the heat medium heated by the cooling water heater 15 circulates; and switching means 35, 36, 37, 38, 40e, 51, and 52 switching a mode to a coupling mode in which the first heat medium circuit C1 is coupled to the second heat medium circuit C2 if a temperature of the heat medium flowing in the first heat medium circuit C1 is lower than a first predetermined temperature Ti, and to a non-coupling mode in which the first heat medium circuit C1 is not coupled to the second heat medium circuit C2 if the temperature of the heat medium flowing in the first heat medium circuit C1 is not lower than a second predetermined temperature Tii.

Description

  The present invention relates to a heat management system used in a vehicle.

  Conventionally, Patent Literature 1 includes an outdoor heat exchanger that exchanges heat between the low-pressure refrigerant in the refrigeration cycle and the outside air, and an indoor condenser that exchanges heat between the high-pressure refrigerant in the refrigeration cycle and the air blown into the vehicle interior. A vehicle air conditioner provided is described.

  In this prior art, in the outdoor heat exchanger, the low-pressure side refrigerant of the refrigeration cycle absorbs heat from the outside air, and in the indoor condenser, the high-pressure side refrigerant of the refrigeration cycle dissipates heat to the air blown into the vehicle interior. Thereby, the heat of external air can be pumped up and the ventilation air to a vehicle interior can be heated. That is, heating can be performed by a heat pump cycle.

JP 2013-052877 A

  In the above prior art, heat exchange is performed between the high-pressure side refrigerant in the refrigeration cycle and the air blown into the vehicle compartment in the indoor condenser, so that if the refrigerant leaks in the indoor condenser, the refrigerant also leaks into the vehicle interior.

  Moreover, in the said prior art, since it is necessary to introduce external air into an outdoor heat exchanger, the outdoor heat exchanger is arrange | positioned in the vehicle frontmost part. Therefore, the outdoor heat exchanger may be destroyed and the refrigerant may be released to the atmosphere just by causing a minor collision accident to the vehicle.

  Therefore, the present applicant has an outdoor evaporator that cools the cooling water by exchanging heat between the low-pressure side refrigerant of the refrigeration cycle and the cooling water, and a first cooling water circuit in which the cooling water cooled by the outdoor evaporator circulates. An outdoor condenser that heats the cooling water by exchanging heat between the high-pressure side refrigerant of the refrigeration cycle and the cooling water, a second cooling water circuit in which the cooling water heated by the outdoor condenser circulates, and a first cooling water circuit Heat exchange between the cooling water circulating through the outside air and the outside air to absorb heat from the outside air to the cooling water, and the cooling water circulating through the second cooling water circuit and the air blown into the vehicle interior exchange heat. A vehicle thermal management system (hereinafter referred to as a study example) including a heater core that heats air blown into the room is being studied.

  In this example, ethylene glycol antifreeze (LLC) is used as the cooling water.

  According to this examination example, the high-pressure side refrigerant in the refrigeration cycle exchanges heat with the cooling water in the outdoor condenser, so that when the refrigerant leaks in the outdoor condenser, the refrigerant can be prevented from leaking into the vehicle interior. Further, since the outdoor heat exchanger exchanges heat between the cooling water of the refrigeration cycle and the outside air, it is possible to prevent the refrigerant from being released to the atmosphere when the outdoor heat exchanger is destroyed due to a vehicle collision accident or the like.

  However, in this examination example, the cooling water cooled by the outdoor evaporator may become below the temperature of the outside air. When the cooling water becomes lower than the temperature of the outside air, the viscosity of the cooling water increases remarkably, so that the pressure loss of the cooling water increases and the flow rate of the cooling water decreases.

  When the flow rate of the cooling water decreases, the temperature of the cooling water further decreases (details will be described later). At this time, if the flow rate of the cooling water is maintained, the power for circulating the cooling water is increased.

  Further, when the temperature of the cooling water cooled by the outdoor evaporator becomes below the freezing point, the moisture in the outside air is solidified by the outdoor heat exchanger and frost is formed. According to the knowledge found by the present applicant through experiments, it has been found that when frost formation proceeds in the outdoor heat exchanger, the temperature of the cooling water is further decreased.

  If the temperature of the cooling water is further reduced, in the worst case, the temperature of the cooling water may fall below the freezing point and the cooling water may solidify.

  Such a problem can also occur when various heat media are used instead of the cooling water.

  An object of this invention is to suppress that the temperature of a thermal medium falls more than necessary in view of the said point.

In order to achieve the above object, in the invention described in claim 1,
An evaporator (14) that cools the heat medium by exchanging heat between the low-pressure side refrigerant of the refrigeration cycle (20) and the heat medium;
A first heat medium circuit (C1) through which the heat medium cooled by the evaporator (14) circulates;
A condenser (15) for heating the heat medium by exchanging heat between the high-pressure side refrigerant of the refrigeration cycle (20) and the heat medium;
A second heat medium circuit (C2) in which the heat medium heated by the condenser (15) circulates;
When the temperature (TW1) of the heat medium flowing through the first heat medium circuit (C1) is lower than the first predetermined temperature (Ti), the first heat medium circuit (C1) and the second heat medium circuit (C2) When the connection mode is switched and the temperature (TW1) of the heat medium flowing through the first heat medium circuit (C1) is equal to or higher than the second predetermined temperature (Tii), the first heat medium circuit (C1) and the second heat Switching means (35, 36, 37, 38, 40e, 51, 52) for switching to a non-connected mode in which the medium circuit (C2) is not connected is provided.

  According to this, when the temperature (TW1) of the heat medium flowing through the first heat medium circuit (C1) is lower than the first predetermined temperature (Ti), the heat medium heated by the condenser (15) is converted into the first heat. The temperature (TW1) of the heat medium flowing into the medium circuit (C1) and flowing through the first heat medium circuit (C1) can be raised.

  For this reason, since the temperature (TW1) of the heat medium flowing through the first heat medium circuit (C1) can be maintained at the first predetermined temperature (Ti) or more, it is possible to suppress the temperature of the heat medium from being lowered more than necessary. .

  In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim shows the correspondence with the specific means as described in embodiment mentioned later.

It is a whole block diagram of the thermal management system for vehicles in a 1st embodiment, and has shown non-connecting mode. It is a whole block diagram of the thermal management system for vehicles in a 1st embodiment, and has shown connection mode. It is a block diagram which shows the electric control part of the thermal management system for vehicles in 1st Embodiment. It is a flowchart explaining the control processing of the thermal management system for vehicles in 1st Embodiment. It is a control characteristic figure used by the control processing of the thermal management system for vehicles in a 1st embodiment. It is a graph which shows the relationship between the temperature of a cooling water, and the viscosity of a cooling water. It is a graph which shows the relationship between the temperature of a cooling water, and the maximum efficiency of a cooling water pump. It is a whole block diagram of the thermal management system for vehicles in 2nd Embodiment.

  Hereinafter, embodiments will be described with reference to the drawings. In the following embodiments, the same or equivalent parts are denoted by the same reference numerals in the drawings.

(First embodiment)
The vehicle thermal management system 10 shown in FIG. 1 is used to adjust various devices and vehicle interiors provided in the vehicle to appropriate temperatures. In the present embodiment, the vehicle thermal management system 10 is applied to a hybrid vehicle that obtains driving force for vehicle travel from an engine (internal combustion engine) and a travel electric motor.

  The hybrid vehicle of the present embodiment is configured as a plug-in hybrid vehicle that can charge power supplied from an external power source (commercial power source) when the vehicle is stopped to a battery (vehicle battery) mounted on the vehicle. As the battery, for example, a lithium ion battery can be used.

  The driving force output from the engine is used not only for driving the vehicle but also for operating the generator. The electric power generated by the generator and the electric power supplied from the external power source can be stored in the battery, and the electric power stored in the battery is not limited to the electric motor for traveling, but also the thermal management system 10 for the vehicle. Is supplied to various in-vehicle devices including the electric component device.

  As shown in FIG. 1, the vehicle thermal management system 10 includes a first pump 11, a second pump 12, a radiator 13, a cooling water cooler 14, a cooling water heater 15, and a heater core 16.

  The first pump 11 and the second pump 12 are cooling water pumps that suck and discharge cooling water (heat medium), and are configured by electric pumps. The cooling water is a fluid as a heat medium. In the present embodiment, as the cooling water, a liquid containing at least ethylene glycol, dimethylpolysiloxane or nanofluid, or an antifreeze liquid is used.

  The radiator 13, the cooling water cooler 14, the cooling water heater 15 and the heater core 16 are cooling water distribution devices (heat medium distribution devices) through which the cooling water flows.

  The radiator 13 is a cooling water outside air heat exchanger (heat medium outside air heat exchanger) that exchanges heat between cooling water and outside air (air outside the passenger compartment). Outside air is blown to the radiator 13 by the outdoor blower 17. The outdoor blower 17 is a blowing unit that blows outside air to the radiator 13. The outdoor blower 17 is an electric blower that drives a blower fan with an electric motor (blower motor).

  The radiator 13 and the outdoor blower 17 are disposed at the foremost part of the vehicle. For this reason, the traveling wind can be applied to the radiator 13 when the vehicle is traveling.

  The cooling water cooler 14 is a low pressure side heat exchanger (heat medium cooler) that cools the cooling water by exchanging heat between the low pressure side refrigerant of the refrigeration cycle 20 and the cooling water. The cooling water cooler 14 can cool the cooling water to a temperature lower than the temperature of the outside air.

  The cooling water heater 15 is a high pressure side heat exchanger (refrigerant cooler) that cools the high pressure side refrigerant by exchanging heat between the high pressure side refrigerant of the refrigeration cycle 20 and the cooling water.

  The refrigeration cycle 20 is a vapor compression refrigerator that includes a compressor 21, a cooling water heater 15, an expansion valve 22, and a cooling water cooler 14. In the refrigeration cycle 20 of the present embodiment, a chlorofluorocarbon refrigerant is used as the refrigerant, and a subcritical refrigeration cycle in which the high-pressure side refrigerant pressure does not exceed the critical pressure of the refrigerant is configured.

  The compressor 21 is an electric compressor driven by electric power supplied from a battery or a variable capacity compressor driven by a belt, and sucks, compresses and discharges the refrigerant of the refrigeration cycle 20. The cooling water heater 15 is a condenser that condenses the high-pressure side refrigerant by exchanging heat between the high-pressure side refrigerant discharged from the compressor 21 and the cooling water.

  The expansion valve 22 is a decompression unit that decompresses and expands the liquid-phase refrigerant that has flowed out of the cooling water heater 15. The cooling water cooler 14 is an evaporator that evaporates the low-pressure refrigerant by exchanging heat between the low-pressure refrigerant decompressed and expanded by the expansion valve 22 and the cooling water. The gas-phase refrigerant evaporated in the cooling water cooler 14 is sucked into the compressor 21 and compressed.

  The heater core 16 is a heating heat exchanger (air heater) that heats the air blown into the vehicle interior by exchanging heat between the cooling water and the air blown into the vehicle interior. Inside air, outside air, or mixed air of inside air and outside air is blown to the heater core 16 by the indoor blower 18.

  The indoor blower 18 is a blower that blows air toward the passenger compartment. The indoor blower 18 is an electric blower that drives a centrifugal multiblade fan (sirocco fan) with an electric motor (blower motor).

  The heater core 16 and the indoor blower 18 are accommodated in the casing 31 of the indoor air conditioning unit 30 of the vehicle air conditioner. The indoor air conditioning unit 30 is disposed inside the instrument panel (instrument panel) at the forefront of the vehicle interior. The casing 31 forms the outer shell of the indoor air conditioning unit.

  The casing 31 forms an air passage for blown air that is blown into the passenger compartment, and is formed of a resin (for example, polypropylene) that has a certain degree of elasticity and is excellent in strength.

  The 1st pump 11, the radiator 13, and the cooling water cooler 14 are arrange | positioned at the 1st cooling water circuit C1 (1st heat medium circuit). The first cooling water circuit C <b> 1 is configured such that cooling water (first heat medium) circulates in the order of the first pump 11 → the cooling water cooler 14 → the radiator 13 → the first pump 11.

  The 2nd pump 12, the cooling water heater 15, and the heater core 16 are arrange | positioned at the 2nd cooling water circuit C2 (2nd heat medium circuit). The second cooling water circuit C <b> 2 is configured so that the cooling water (second heat medium) circulates in the order of the second pump 12 → the heater core 16 → the cooling water heater 15 → the second pump 12.

  A first connection channel 32 and a second connection channel 33 are connected to the first coolant circuit C1 and the second coolant circuit C2.

  One end of the first connection channel 32 is connected to a portion of the first cooling water circuit C1 on the cooling water outlet side of the radiator 13 and the cooling water suction side of the first pump 11. The other end of the first connection channel 32 is connected to a portion of the second cooling water circuit C2 on the cooling water outlet side of the cooling water heater 15 and the cooling water suction side of the second pump 12.

  One end of the second connection channel 33 is connected to a portion of the first cooling water circuit C1 on the cooling water outlet side of the cooling water cooler 14 and the cooling water inlet side of the radiator 13. The other end of the second connection channel 33 is connected to a portion of the second cooling water circuit C2 on the cooling water outlet side of the heater core 16 and the cooling water inlet side of the cooling water heater 15.

  A third pump 34 is disposed in the first connection channel 32. The third pump 34 is a cooling water pump that sucks and discharges the cooling water (heat medium) of the first connection flow path 32, and is configured by an electric pump.

  A first on-off valve 35 is disposed at a connection portion between the first connection channel 32 and the first cooling water circuit C1. A second on-off valve 36 is disposed at a connection portion between the first connection channel 32 and the second cooling water circuit C2. A third on-off valve 37 is disposed at a connection portion between the second connection channel 33 and the first cooling water circuit C1. A fourth on-off valve 38 is disposed at a connection portion between the second connection channel 33 and the second cooling water circuit C2.

  The first to fourth opening / closing valves 35 to 38 are opening / closing means for opening and closing the first connection channel 32 and the second connection channel 33, and are constituted by, for example, electromagnetic valves. The 1st-4th on-off valves 35-38 comprise the switching means which switches the non-connection mode shown in FIG. 1, and the connection mode shown in FIG.

  In the non-connection mode, the first to fourth on-off valves 35 to 38 close the first connection flow path 32 and the second connection flow path 33. Thereby, the 1st cooling water circuit C1 and the 2nd cooling water circuit C2 are not connected.

  In the connection mode, the first to fourth on-off valves 35 to 38 open the first connection channel 32 and the second connection channel 33. Thereby, the 1st cooling water circuit C1 and the 2nd cooling water circuit C2 are connected.

  Further, in the connection mode, the first pump 11 and the second pump 12 are stopped and the third pump 34 is operated. Thereby, the cooling water circulates in the order of the third pump 34 → the cooling water heater 15 and the heater core 16 (parallel flow) → the radiator 13 and the cooling water cooler 14 (parallel flow) → the third pump 34.

  The control device 40 shown in FIG. 3 is composed of a well-known microcomputer including a CPU, ROM, RAM, etc. and its peripheral circuits, and performs various calculations and processing based on an air conditioning control program stored in the ROM, and outputs it. Control means for controlling the operation of the first pump 11, the second pump 12, the outdoor blower 17, the indoor blower 18, the compressor 21, the third pump 34, the first to fourth on-off valves 35 to 38, etc. connected to the side It is.

  The control device 40 is configured integrally with control means for controlling various control target devices connected to the output side thereof, but has a configuration (hardware and software) for controlling the operation of each control target device. The control means for controlling the operation of each control target device is configured.

  The structure (hardware and software) which controls the action | operation of the 1st pump 11 among the control apparatuses 40 comprises the 1st cooling water flow control means 40a (1st heat medium flow control means).

  The structure (hardware and software) which controls the action | operation of the 2nd pump 12 among the control apparatuses 40 comprises the 2nd cooling water flow control means 40b (2nd heat-medium flow control means).

  The structure (hardware and software) which controls the action | operation of the compressor 21 among the control apparatuses 40 comprises the refrigerant | coolant flow control means 40c.

  The configuration (hardware and software) for controlling the operation of the third pump 34 in the control device 40 constitutes the third cooling water flow rate control means 40d (third heat medium flow rate control means).

  The structure (hardware and software) which controls the action | operation of the 1st-4th on-off valve 35-38 among the control apparatuses 40 comprises the switching control means 40e. The switching control unit 40e constitutes a switching unit that switches between the non-connected mode and the connected mode.

  The first cooling water flow rate control means 40a, the second cooling water flow rate control means 40b, the refrigerant flow rate control means 40c, the third cooling water flow rate control means 40d, and the switching control means 40e are configured separately from the control device 40. It may be.

  Detection signals of sensor groups such as the inside air sensor 41, the outside air sensor 42, the first water temperature sensor 43, the second water temperature sensor 44, and the refrigerant temperature sensor 45 are input to the input side of the control device 40.

  The inside air sensor 41 is a detection means (inside air temperature detection means) that detects the inside air temperature (in-vehicle temperature). The outside air sensor 42 is a detection means (outside air temperature detection means) that detects an outside air temperature (a temperature outside the passenger compartment).

  The first water temperature sensor 43 is detection means (first heat medium temperature detection means) for detecting the temperature of the cooling water flowing through the first cooling water circuit C1 (for example, the temperature of the cooling water sucked into the first pump 11). .

  The second water temperature sensor 44 is detection means (second heat medium temperature detection means) for detecting the temperature of the cooling water flowing through the second cooling water circuit C2 (for example, the temperature of the cooling water sucked into the second pump 12). .

  The refrigerant temperature sensor 45 is detection means (refrigerant temperature detection means) for detecting the refrigerant temperature of the refrigeration cycle 20 (for example, the temperature of the refrigerant discharged from the compressor 21).

  The inside air temperature, the outside air temperature, the cooling water temperature, and the refrigerant temperature may be estimated based on detection values of various physical quantities.

  An operation signal from the air conditioner switch 48 is input to the input side of the control device 40. The air conditioner switch 48 is a switch for switching on / off of the air conditioner (in other words, cooling on / off), and is disposed near the instrument panel in the vehicle interior.

  Next, the operation in the above configuration will be described. When the vehicle thermal management system 10 is activated, the control device 40 controls the operation of the first to fourth on-off valves 35 to 38 so as to be in the non-connected mode shown in FIG. The pump 12 and the compressor 21 are operated. Thereby, the refrigerant circulates in the refrigeration cycle 20, the cooling water circulates in the first cooling water circuit C1, and the cooling water circulates in the second cooling water circuit C2.

  In the cooling water cooler 14, since the refrigerant of the refrigeration cycle 20 absorbs heat from the cooling water of the first cooling water circuit C1, the cooling water of the first cooling water circuit C1 is cooled. The refrigerant of the refrigeration cycle 20 that has absorbed heat from the cooling water of the first cooling water circuit C1 by the cooling water cooler 14 radiates heat to the cooling water of the second cooling water circuit C2 by the cooling water heater 15. Thereby, the cooling water of the 2nd cooling water circuit C2 is heated.

  The cooling water in the second cooling water circuit C <b> 2 heated by the cooling water heater 15 radiates heat to the blown air blown by the indoor blower 18 in the heater core 16. Therefore, the air blown into the passenger compartment is heated.

  The cooling water of the first cooling water circuit C1 cooled by the cooling water cooler 14 absorbs heat from the outside air blown by the outdoor blower 17 in the radiator 13. Therefore, it is possible to realize a heat pump operation that pumps up the heat of the outside air.

  Thus, in the state switched to the non-connection mode, the control apparatus 40 implements the control process shown in the flowchart of FIG.

  In step S100, it is detected whether or not the temperature TW1 of the cooling water flowing through the first cooling water circuit C1 is lower than the first predetermined temperature Ti. The first predetermined temperature Ti is a value stored in the control device 40 in advance.

  If it is determined in step S100 that the temperature TW1 of the coolant flowing through the first coolant circuit C1 is not lower than the first predetermined temperature Ti, step S100 is repeated. Accordingly, the disconnected mode is maintained.

  In step S100, when it is determined that the temperature TW1 of the cooling water flowing through the first cooling water circuit C1 is lower than the first predetermined temperature Ti, the process proceeds to step S110, the connection mode is switched to, and the process proceeds to step S120. In the connection mode, the first pump 11 and the second pump 12 are stopped, and the third pump 34 is operated.

  As a result, the first cooling water circuit C1 and the second cooling water circuit C2 are connected, and the high-temperature cooling water of the second cooling water circuit C2 flows into the first cooling water circuit C1, so the first cooling water circuit C1. The temperature TW1 of the cooling water flowing through the water rises.

  At this time, the control device 40 controls the flow rate GW of the cooling water flowing into the first cooling water circuit C1 from the second cooling water circuit C2 based on the control map shown in FIG.

  That is, the larger the temperature difference ΔT = TW2−TW1 obtained by subtracting the temperature TW1 of the cooling water flowing through the first cooling water circuit C1 from the temperature TW2 of the cooling water flowing through the second cooling water circuit C2, the larger the temperature difference from the second cooling water circuit C2. The flow rate GW of the cooling water flowing into the first cooling water circuit C1 is reduced.

  Thereby, when switching from the non-connection mode to the connection mode, it is possible to prevent the first cooling water circuit C1 from being suddenly subjected to a heat load and causing thermal distortion in the components of the first cooling water circuit C1.

  The control of the coolant flow rate GW can be performed, for example, by controlling the number of rotations (cooling water discharge capacity) of the third pump 34 or opening control of the first to fourth on-off valves 35 to 38.

  In step S110, the first pump 11 and the second pump 12 are not necessarily stopped.

  In step S120, it is detected whether or not the temperature TW1 of the coolant flowing through the first coolant circuit C1 is equal to or higher than the second predetermined temperature Tii. The second predetermined temperature Tii is a value stored in the control device 40 in advance, and is a value larger than the first predetermined temperature Ti.

  If it is determined in step S120 that the temperature TW1 of the cooling water flowing through the first cooling water circuit C1 is not equal to or higher than the second predetermined temperature Tii, step S120 is repeated. Therefore, the connection mode is maintained.

  In step S120, when it is determined that the temperature TW1 of the cooling water flowing through the first cooling water circuit C1 is equal to or higher than the second predetermined temperature Tii, the process proceeds to step S130, and is switched to the disconnected mode. As a result, the first cooling water circuit C1 and the second cooling water circuit C2 are disconnected, and the high-temperature cooling water of the second cooling water circuit C2 does not flow into the first cooling water circuit C1, so the first cooling water circuit The temperature TW1 of the cooling water flowing through C1 decreases.

  Thus, the temperature TW1 of the cooling water flowing through the first cooling water circuit C1 is changed to the first predetermined temperature by switching between the non-connected mode and the connecting mode according to the temperature TW1 of the cooling water flowing through the first cooling water circuit C1. It can be kept in a range not less than Ti and not more than the second predetermined temperature Tii.

  Here, the problem which arises when the temperature of cooling water falls more than necessary is demonstrated. FIG. 6 is a graph showing the relationship between the temperature of the cooling water and the viscosity of the cooling water when the cooling water is an ethylene glycol antifreeze (LLC). As shown in FIG. 6, the viscosity of the cooling water increases significantly when the temperature of the cooling water is lowered. When the viscosity of the cooling water increases, there is a problem that the pressure loss of the cooling water increases and the flow rate of the cooling water decreases. At this time, if the flow rate of the cooling water is to be maintained, an increase in power for circulating the cooling water is caused.

When the flow rate of the cooling water decreases, as the behavior of the cooling water cooler 14, in order to maintain the heat exchange capability, the temperature difference between the inlet cooling water temperature Tin and the outlet cooling water temperature Tout of the cooling water cooler 14 increases. It is thought to balance in the direction. That is, it is considered that the outlet cooling water temperature Tout of the cooling water cooler 14 is lowered. This is clear from the following equation.
Q = cpw · Gw · (Tin-Tout)
Where Q is the heat exchange capacity, cpw is the specific heat of the cooling water, and Gw is the mass flow rate of the cooling water.

  When the outlet cooling water temperature Tout of the cooling water cooler 14 is lowered, the temperature of the cooling water is further lowered.

  When the temperature of the cooling water flowing through the radiator 13 becomes less than the freezing point, moisture in the outside air is solidified by the radiator 13 and frost is formed. According to the knowledge found by the present applicant through experiments, it has been found that the temperature of the cooling water is further lowered as frosting progresses in the radiator 13.

  If the temperature of the cooling water is further decreased, in the worst case, there is a problem that the temperature of the cooling water falls below the freezing point and the cooling water solidifies. In particular, when the cooling water pump is stopped, no pressure is applied to the cooling water, so that the cooling water is easily solidified. Therefore, a situation may occur in which the cooling water does not flow when the cooling water pump is restarted.

  Moreover, as shown in FIGS. 6 and 7, when the temperature of the cooling water is lowered, there is a problem that the efficiency of the cooling water pump is deteriorated by increasing the viscosity of the cooling water.

  In particular, when the cooling water is an ethylene glycol antifreeze (LLC), the cooling water temperature easily becomes −20 ° C. or less due to the influence of frost formation. In this temperature range, as shown in FIG. Remarkably higher. As a result, the above-mentioned problem becomes remarkable.

  According to this embodiment, since the temperature TW1 of the cooling water flowing through the first cooling water circuit C1 can be kept at the first predetermined temperature Ti or higher, it is possible to prevent the temperature of the cooling water from being lowered more than necessary. Therefore, it can suppress that the above-mentioned problem occurs.

  In the present embodiment, the first to fourth on-off valves 35, 36, 37, 38 and the control device 40 (switching control means 40e) are such that the temperature TW1 of the cooling water flowing through the first cooling water circuit C1 is equal to or lower than a predetermined temperature Ti. In some cases, the first cooling water circuit C1 and the second cooling water circuit C2 are switched to a connection mode in which the first cooling water circuit C1 and the second cooling water circuit C2 are connected. The operation mode is switched to the non-connected mode in which the cooling water circuit C1 and the second cooling water circuit C2 are not connected.

  According to this, when the temperature TW1 of the cooling water flowing through the first cooling water circuit C1 is equal to or lower than the predetermined temperature Ti, the cooling water of the second cooling water circuit C2 (the cooling water heated by the cooling water heater 15) is changed to the first. The temperature TW1 of the cooling water flowing into the first cooling water circuit C1 and flowing through the first cooling water circuit C1 can be raised.

  For this reason, since the temperature TW1 of the cooling water flowing through the first cooling water circuit C1 can be kept at the predetermined temperature Ti or higher, it is possible to suppress the temperature of the cooling water from being lowered more than necessary.

  In the present embodiment, in the connection mode, the cooling water flows from the second cooling water circuit C2 to the evaporator 14. According to this, since the temperature of the cooling water flowing through the evaporator 14 can be raised, the viscosity of the cooling water cooled by the evaporator 14 increases or the cooling water solidifies in the evaporator 14. Can be suppressed.

  In the present embodiment, cooling water flows from the second cooling water circuit C2 to the radiator 13 in the connection mode. According to this, since the temperature of the cooling water flowing through the radiator 13 can be increased, it is possible to suppress an increase in the viscosity of the cooling water flowing through the radiator 13 and an increase in the pressure loss of the cooling water in the first cooling water circuit C1. it can.

  In the present embodiment, in the connection mode, the cooling water flows from the cooling water heater 15 to the first cooling water circuit C1. According to this, since the high-temperature cooling water heated by the cooling water heater 15 flows through the first cooling water circuit C1, the temperature of the cooling water flowing through the first cooling water circuit C1 can be effectively increased.

  In the present embodiment, in the connection mode, the cooling water flows from the heater core 16 to the first cooling water circuit C1. According to this, since the high-temperature cooling water of the second cooling water circuit C2 flows through the first cooling water circuit C1, the temperature of the cooling water flowing through the first cooling water circuit C1 can be increased.

  In the present embodiment, the larger the temperature difference ΔT obtained by subtracting the temperature TW1 of the cooling water flowing through the first cooling water circuit C1 from the temperature TW2 of the cooling water flowing through the second cooling water circuit C2, the larger the temperature difference from the second cooling water circuit C2. 1 Flow rate of the cooling water flowing into the cooling water circuit C1 is reduced.

  As a result, it is possible to prevent the first cooling water circuit C1 from being suddenly subjected to a heat load and causing thermal distortion in the components of the first cooling water circuit C1.

  In the case where the cooling water is an ethylene glycol antifreeze, the above-described effects are remarkable.

(Second Embodiment)
In the above embodiment, the connection mode and the non-connection mode are switched by the first to fourth on-off valves 35 to 38. In the present embodiment, as shown in FIG. 8, the first switching valve 51 and the second switching valve 52 are switched. To switch between connected mode and unconnected mode.

  In the present embodiment, the vehicle thermal management system 10 includes a heat generating device 53. The heat generating device 53 is a heat generating device that generates heat when activated. The heat generating device 53 is a device (a temperature adjustment target device) that has a flow path through which the cooling water flows and that exchanges heat with the cooling water.

  Examples of the heat generating device 53 include an inverter, a battery, a traveling electric motor, an engine, and a fuel cell. The inverter is a power conversion device that converts DC power supplied from a battery into an AC voltage and outputs the AC voltage to a traveling electric motor.

  The first switching valve 51 and the second switching valve 52 are switching means (heat medium flow switching means) that switches the flow of cooling water.

  The first switching valve 51 is a multi-way valve having a large number of ports (first switching valve ports) constituting the inlet or outlet of the cooling water. Specifically, the first switching valve 51 has a first inlet 51a and a second inlet 51b as cooling water inlets, and first to fourth outlets 51c to 51f as cooling water outlets.

  The 2nd switching valve 52 is a multi-way valve which has many ports (2nd switching valve port) which comprise the inlet_port | entrance or exit of a cooling water. Specifically, the second switching valve 52 has a first outlet 52a and a second outlet 52b as cooling water outlets, and has first to fourth inlets 52c to 52f as cooling water inlets.

  One end of the first flow path 54 is connected to the first inlet 51 a of the first switching valve 51. The other end of the first flow path 54 is connected to the first outlet 52 a of the second switching valve 52. The first pump 11 and the radiator 13 are arranged in the first flow path 54.

  One end of the second flow path 55 is connected to the second inlet 51 b of the first switching valve 51. The other end of the second flow path 55 is connected to the second outlet 52 b of the second switching valve 52. The second pump 12 is disposed in the second flow path 55.

  One end of the third flow path 56 is connected to the first outlet 51 c of the first switching valve 51. The other end of the third flow path 56 is connected to the first inlet 52 c of the second switching valve 52. The cooling water cooler 14 is disposed in the third flow path 56.

  One end of the fourth flow path 57 is connected to the second outlet 51 d of the first switching valve 51. The other end of the fourth flow path 57 is connected to the second inlet 52 d of the second switching valve 52. The cooling water heater 15 is disposed in the fourth flow path 57.

  One end of a fifth flow path 58 is connected to the third outlet 51 e of the first switching valve 51. The other end of the fifth flow path 58 is connected to the third inlet 52e of the second switching valve 52. The heater core 16 is disposed in the fifth flow path 58.

  One end of a sixth flow path 59 is connected to the fourth outlet 51 f of the first switching valve 51. The other end of the sixth flow path 59 is connected to the fourth inlet 52 f of the second switching valve 52. A heat generating device 53 is disposed in the sixth flow path 59.

  The first switching valve 51 has a structure capable of arbitrarily or selectively switching the communication state between the inlets 51a and 51b and the outlets 51c to 51f. The second switching valve 52 is also configured to be able to arbitrarily or selectively switch the communication state between the outlets 52a and 52b and the inlets 52c to 52f.

  Specifically, the first switching valve 51 has a state in which the cooling water discharged from the first pump 11 flows into each of the cooling water cooler 14, the cooling water heater 15, the heater core 16, and the heating device 53, and The state where the cooling water discharged from the two pumps 12 flows in and the state where the cooling water discharged from the first pump 11 and the cooling water discharged from the second pump 12 do not flow are switched.

  The second switching valve 52 is in a state where the cooling water flows out to the first pump 11 and the cooling water flows out to the second pump 12 for each of the cooling water cooler 14, the cooling water heater 15, the heater core 16, and the heating device 53. And a state in which the cooling water does not flow out to the first pump 11 and the second pump 12.

  The structure example of the first switching valve 51 and the second switching valve 52 will be briefly described. The first switching valve 51 and the second switching valve 52 include a case forming an outer shell and a valve body accommodated in the case. The cooling water inlet and outlet are formed at predetermined positions of the case, and the communication state between the cooling water inlet and outlet is changed by rotating the valve body.

  The valve body of the first switching valve 51 and the valve body of the second switching valve 52 are independently driven to rotate by separate electric motors. The operation of the electric motor for the first switching valve 51 and the electric motor for the second switching valve 52 is controlled by the control device 40. The valve body of the first switching valve 51 and the valve body of the second switching valve 52 may be rotationally driven in conjunction with a common electric motor.

  The control device 40 controls the operation of the electric motor for the first switching valve 51 and the electric motor for the second switching valve 52, thereby switching to various operation modes.

  For example, in the non-connected mode, the first cooling water circuit C1 (first heat medium circuit) is configured by the first flow path 54 and at least one of the third to sixth flow paths 56 to 59, and the first The second cooling water circuit C2 (second heat medium circuit) is configured by at least another one of the two flow paths 55 and the third to sixth flow paths 56 to 59.

  About each of the 3rd-6th flow paths 56-59, a cooling water is switched by switching between the case where it is connected to the 1st cooling water circuit C1, and the case where it is connected to the 2nd cooling water circuit C2. The cooler 14, the coolant heater 15, the heater core 16, and the heat generating device 53 can be adjusted to appropriate temperatures according to the situation.

  As shown in FIG. 8, when the cooling water cooler 14 and the radiator 13 are connected to the first cooling water circuit C1, and the cooling water heater 15 and the heater core 16 are connected to the second cooling water circuit C2, The vehicle interior can be heated by the heat pump operation of the refrigeration cycle 21.

  That is, in the first cooling water circuit C1, the cooling water cooled by the cooling water cooler 14 flows through the radiator 13, so that the cooling water absorbs heat from the outside air by the radiator 13. The cooling water that has absorbed heat from the outside air by the radiator 13 exchanges heat with the refrigerant of the refrigeration cycle 21 by the cooling water cooler 14 and dissipates heat. Therefore, in the cooling water cooler 14, the refrigerant of the refrigeration cycle 21 absorbs heat from the outside air through the cooling water.

  The refrigerant that has absorbed heat from the outside air in the cooling water cooler 14 exchanges heat with the cooling water in the second cooling water circuit C2 in the cooling water heater 15 to radiate heat. Therefore, the cooling water heater 15 heats the cooling water. The cooling water heated by the cooling water heater 15 exchanges heat with the air blown into the passenger compartment in the heater core 16 to radiate heat. Therefore, the air blown into the passenger compartment is heated in the heater core 16.

  Therefore, it is possible to realize a heat pump operation that pumps up the heat of the outside air and heats the air blown into the vehicle interior.

  In the connection mode, the first switching valve 51 and the second switching valve 52 connect the first cooling water circuit C1 and the second cooling water circuit C2. Thereby, since the high temperature cooling water of the 2nd cooling water circuit C2 flows in into the 1st cooling water circuit C1, the temperature TW1 of the cooling water which flows through the 1st cooling water circuit C1 can be raised.

  That is, in the non-connected mode, the first switching valve 51 switches the cooling water flow so that the cooling water does not flow into the first cooling water circuit C1 from the second cooling water circuit C2, and the second switching valve 52 The flow of the cooling water is switched so that the cooling water does not flow into the second cooling water circuit C2 from the first cooling water circuit C1.

  On the other hand, in the connection mode, the first switching valve 51 switches the cooling water flow so that the cooling water flows from the second cooling water circuit C2 to the first cooling water circuit C1, and the second switching valve 52 The flow of the cooling water is switched so that the cooling water flows from the first cooling water circuit C1 to the second cooling water circuit C2.

  Thereby, the connection mode and the non-connection mode can be switched by the first switching valve 51 and the second switching valve 52.

  In the operation mode shown in FIG. 8, the heat generating device 53 is connected to the first cooling water circuit C1. According to this, the cooling water circulating through the first cooling water circuit C <b> 1 is heated by the waste heat of the heat generating device 53. Therefore, the temperature of the cooling water circulating through the first cooling water circuit C1 can be suppressed from being unnecessarily lowered, and the heating device 53 can be cooled by the cooling water circulating through the first cooling water circuit C1.

(Other embodiments)
The above embodiments can be combined as appropriate. The above embodiment can be variously modified as follows, for example.

  (1) In the first embodiment, four three-way valves may be arranged instead of the four on-off valves 35 to 38. Each three-way valve has three ports (cooling water inlet / outlet), and two of the three ports communicate with each other and the remaining one port is closed.

  When four three-way valves are arranged instead of the four on-off valves 35 to 38, in the connection mode, the cooling water is supplied from the third pump 34 → the cooling water heater 15 or the heater core 16 → the radiator 13 or the cooling water cooler. 14 → 3rd pump 34 is circulated in this order.

  That is, if four three-way valves are arranged instead of the four on-off valves 35 to 38, the cooling water does not circulate in any one of the cooling water heater 15 and the heater core 16 in the connection mode, and the radiator 13 and the cooling It is possible to prevent the cooling water from circulating in either one of the water coolers 14.

  In the connection mode, if the cooling water heated by the cooling water heater 15 does not flow through the first cooling water circuit C1, the heat quantity of the cooling water can be left in the cooling water heater 15. The refrigeration cycle 20 can quickly exhibit performance when switched to the connected mode.

  (2) In the first embodiment, the second cooling water circuit C2 is provided with a bypass flow path through which the cooling water bypasses the heater core 16, and the cooling water flows through the bypass core in the connection mode. It may not be possible.

  According to this, in the connection mode, the cooling water heated by the cooling water heater 15 is allowed to flow to the first cooling water circuit C1 while heating the blown air into the vehicle interior with the heat of the cooling water remaining in the heater core 16. Therefore, it can suppress that the temperature of the cooling water of the 1st cooling water circuit C1 falls more than necessary, without stopping heating of a vehicle interior.

  (3) In the second embodiment, the number of ports of the first switching valve 51, the number of ports of the second switching valve 52, and the number of channels connected to the first and second switching valves 51 and 52 are as follows. It can be increased or decreased as appropriate.

  (4) In the said embodiment, the thermal storage may be provided in the 2nd cooling water circuit C2. The heat accumulator is heat storage means for storing heat of the coolant flowing through the second coolant circuit C2. As the heat accumulator, for example, a heat insulating container for storing high-temperature cooling water, a member having a large heat capacity, or the like can be used.

  (5) In the above embodiment, cooling water is used as the heat medium flowing through the heater core 16, but various media such as oil may be used as the heat medium.

  A nanofluid may be used as the heat medium. A nanofluid is a fluid in which nanoparticles having a particle size of the order of nanometers are mixed. In addition to the effect of lowering the freezing point as in the case of cooling water using ethylene glycol (so-called antifreeze liquid), the following effects can be obtained by mixing the nanoparticles with the heat medium.

  That is, the effect of improving the thermal conductivity in a specific temperature range, the effect of increasing the heat capacity of the heat medium, the effect of preventing the corrosion of metal pipes and the deterioration of rubber pipes, and the heat medium at an extremely low temperature The effect which improves the fluidity | liquidity of can be acquired.

  Such effects vary depending on the particle configuration, particle shape, blending ratio, and additional substance of the nanoparticles.

  According to this, since the thermal conductivity can be improved, it is possible to obtain the same cooling efficiency even with a small amount of heat medium as compared with the cooling water using ethylene glycol.

  Moreover, since the heat capacity of the heat medium can be increased, the amount of heat stored in the heat medium itself (cold heat stored by sensible heat) can be increased.

  Even if the compressor 21 is not operated by increasing the amount of cold storage heat, the temperature and temperature of the equipment can be controlled using the cold storage heat for a certain amount of time. Motorization becomes possible.

  The aspect ratio of the nanoparticles is preferably 50 or more. This is because sufficient thermal conductivity can be obtained. The aspect ratio is a shape index that represents the ratio of the vertical and horizontal dimensions of the nanoparticles.

  Nanoparticles containing any of Au, Ag, Cu and C can be used. Specifically, Au nanoparticle, Ag nanowire, CNT (carbon nanotube), graphene, graphite core-shell nanoparticle (a structure such as a carbon nanotube surrounding the above atom is included as a constituent atom of the nanoparticle. Particles), Au nanoparticle-containing CNTs, and the like can be used.

  (6) In the refrigeration cycle 20 of the above embodiment, a chlorofluorocarbon refrigerant is used as the refrigerant. However, the type of the refrigerant is not limited to this, and natural refrigerant such as carbon dioxide, hydrocarbon refrigerant, or the like is used. May be.

  The refrigeration cycle 20 of the above embodiment constitutes a subcritical refrigeration cycle in which the high-pressure side refrigerant pressure does not exceed the critical pressure of the refrigerant. You may comprise.

  (7) In the above-described embodiment, an example in which the vehicle thermal management system 10 is applied to a hybrid vehicle has been described. However, vehicle heat is applied to an electric vehicle or the like that does not include an engine and obtains driving force for vehicle traveling from a traveling electric motor. The management system 10 may be applied.

13 Radiator 14 Cooling water cooler (evaporator)
15 Cooling water heater (condenser)
16 heater core 20 refrigeration cycle 35, 36, 37, 38 1st-4th on-off valve (switching means)
40d Third cooling water flow rate control means (flow rate control means)
40e Switching control means (switching means)
C1 first cooling water circuit (first heat medium circuit)
C2 Second cooling water circuit (second heat medium circuit)

Claims (8)

An evaporator (14) that cools the heat medium by exchanging heat between the low-pressure side refrigerant of the refrigeration cycle (20) and the heat medium;
A first heat medium circuit (C1) through which the heat medium cooled by the evaporator (14) circulates;
A condenser (15) for heating the heat medium by exchanging heat between the high-pressure refrigerant of the refrigeration cycle (20) and the heat medium;
A second heat medium circuit (C2) in which the heat medium heated by the condenser (15) circulates;
When the temperature (TW1) of the heat medium flowing through the first heat medium circuit (C1) is lower than a first predetermined temperature (Ti), the first heat medium circuit (C1) and the second heat medium circuit ( C2) is connected to the connection mode, and when the temperature (TW1) of the heat medium flowing through the first heat medium circuit (C1) is equal to or higher than a second predetermined temperature (Tii), the first heat medium circuit (C1) and a switching means (35, 36, 37, 38, 40e, 51, 52) for switching to a non-connected mode in which the second heat medium circuit (C2) is not connected. Management system. The switching means is
In the case of the connected mode, the heat medium is caused to flow from the second heat medium circuit (C2) to the first heat medium circuit (C1), and in the case of the non-connected mode, from the second heat medium circuit (C2). A first switching valve (51) that switches the flow of the heat medium so that the heat medium does not flow into the first heat medium circuit (C1);
In the case of the connected mode, the heat medium is caused to flow from the first heat medium circuit (C1) to the second heat medium circuit (C2), and in the case of the non-connected mode, from the first heat medium circuit (C1). The vehicle according to claim 1, further comprising a second switching valve (52) for switching the flow of the heat medium so that the heat medium does not flow into the second heat medium circuit (C2). Heat management system.   In the connection mode, the switching means includes the first heat medium circuit (C1) and the second heat medium so that the heat medium flows from the second heat medium circuit (C2) to the evaporator (14). The thermal management system for a vehicle according to claim 1 or 2, wherein the circuit (C2) is connected. A radiator (13) disposed in the first heat medium circuit (C1) and configured to exchange heat between the heat medium cooled by the evaporator (14) and the outside air;
In the connection mode, the switching means includes the first heat medium circuit (C1) and the second heat medium circuit so that the heat medium flows from the second heat medium circuit (C2) to the radiator (13). The vehicle thermal management system according to any one of claims 1 to 3, wherein (C2) is connected.   In the connection mode, the switching means is configured such that the heat medium flows from the condenser (15) to the first heat medium circuit (C1) so that the heat medium flows to the first heat medium circuit (C1) and the second heat medium. The vehicle thermal management system according to any one of claims 1 to 4, wherein the circuit (C2) is connected. A heater core (16) disposed in the second heat medium circuit (C2) and configured to exchange heat between the heat medium heated by the condenser (15) and the air blown into the vehicle interior;
In the connection mode, the switching means includes the first heat medium circuit (C1) and the second heat medium circuit so that the heat medium flows from the heater core (16) to the first heat medium circuit (C1). The vehicle thermal management system according to claim 1, wherein the vehicle thermal management system is connected to (C2).   As the temperature difference (ΔT) obtained by subtracting the temperature (TW1) of the heat medium flowing through the first heat medium circuit (C1) from the temperature (TW2) of the heat medium flowing through the second heat medium circuit (C2) is larger. Flow rate control means (34, 35, 36, 37, 38, 40d, 40e) for reducing the flow rate of the heat medium flowing into the first heat medium circuit (C1) from the second heat medium circuit (C2); The vehicle thermal management system according to any one of claims 1 to 6, further comprising:   The vehicle heat management system according to claim 1, wherein the heat medium is an ethylene glycol antifreeze.

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