JP2024014440A - Vehicular air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve comfort of an occupant even just after switching an operation mode.

SOLUTION: A vehicular air conditioner is provided with: a heat medium circuit through which a heat medium heated or cooled through heat exchange with a heat source circulates; an air-conditioning unit in which a heat exchanger that makes the heat medium circulating through the heat medium circuit exchange heat with air is arranged in an air flow passage and which blows out the air whose temperature has been adjusted by the heat exchanger to the inside of a vehicle interior; and a control part that controls the heat source, the heat medium circuit and the air-conditioning unit, and executes a plurality of operation modes while switching the modes. In switching the operation modes, the control part performs, when a target temperature set in the switched operation mode is higher than a threshold, pre-heating control of preheating the heat medium in the heat medium circuit or not, before switching the operation mode.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a vehicle air conditioner.

In a vehicle air conditioner, an air conditioning unit has multiple heat exchangers (heater core, cooler core) arranged on the air circulation path to exchange heat with the refrigerant circulating in the refrigerant circuit serving as the heat source and the air either directly or via another heat medium. The vehicle interior is air-conditioned by supplying heated or cooled air into the vehicle interior from the air outlet of the air conditioning unit. Such a vehicle air conditioner can execute multiple operation modes including a heating mode in which air heated by the heater core is supplied into the vehicle interior, and a cooling mode in which air cooled by the cooler core is supplied into the vehicle interior. The operation mode is selectively switched and executed according to the set target temperature (for example, Patent Document 1).

Japanese Patent Application Publication No. 2004-230997

In a vehicle air conditioner, for example, when switching the operating mode, if the difference between the target temperatures before and after switching is large, the temperature of the heat medium passing through the heater core or cooler core immediately after switching the operating mode will be higher than the air at the target temperature. The temperature may not be reached for blowing out. In this case, the air blown out from the air conditioning unit does not reach the target temperature for a while after switching the driving mode, and the comfort in the vehicle interior is impaired.

The present invention aims to address such problems. That is, an object of the present invention is to improve the comfort of occupants in a vehicle air conditioner even immediately after switching the driving mode.

In order to solve such problems, one embodiment of the present invention includes the following configuration.
That is, a vehicle air conditioner according to one aspect of the present invention includes a heat medium circuit in which a heat medium heated or cooled by heat exchange with a heat source circulates, and a heat medium and air circulating in the heat medium circuit. A heat exchanger for heat exchange is arranged in an air flow path, and an air conditioning unit blows out air whose temperature has been adjusted by the heat exchanger into a vehicle interior, and the heat source, the heat medium circuit, and the air conditioning unit are controlled. a control unit that switches and executes a plurality of operation modes, and when switching the operation mode, if a target temperature set in the operation mode after switching is higher than a threshold value, the control unit switches the operation mode. A vehicle air conditioner is provided that performs preheating control to determine whether or not to preheat the heat medium in the heat medium circuit before switching modes.

According to the vehicle air conditioner of the present invention having such features, the comfort of the occupant can be improved even immediately after switching the driving mode.

1 is an explanatory diagram showing a schematic configuration of a vehicle air conditioner according to an embodiment of the present invention. FIG. 1 is a block diagram showing a schematic configuration of a control section of a vehicle air conditioner according to an embodiment of the present invention. It is a flowchart which shows the flow of the determination process of whether or not to perform preheating control in the vehicle air conditioner according to the embodiment of the present invention. It is a flowchart which shows the flow of preheating control processing concerning Example 1 in a vehicle air conditioner of an embodiment of the present invention. It is a flowchart which shows the flow of the preheating control process based on Example 2 in the vehicle air conditioner of embodiment of this invention. It is a flow chart which shows the flow of preheating control processing concerning Example 3 in a vehicle air conditioner of an embodiment of the present invention.

Embodiments of the present invention will be described below with reference to the drawings. In the following description, the same reference numerals in different figures indicate parts with the same function, and redundant explanation in each figure will be omitted as appropriate.

FIG. 1 shows a schematic configuration of a refrigerant circuit R, a heat medium circuit W, and an air conditioning unit 10 of a vehicle air conditioner 1 according to an embodiment of the present invention, and FIG. 2 shows a schematic configuration of a refrigerant circuit R, a heat medium circuit W, and an air conditioning unit 10 shown in FIG. A schematic configuration of a control section that controls the circuit W and the air conditioning unit 10 is shown.
As shown in FIGS. 1 and 2, the vehicle air conditioner 1 includes a refrigerant circuit R, a heat medium circuit W, an air conditioning unit 10, and a control unit that controls the refrigerant circuit R, the heat medium circuit W, and the air conditioning unit 10. 100.

The refrigerant circuit R includes a compressor 2 that is driven by a vehicle running battery and compresses refrigerant, a condenser 3, an expansion valve 4, an evaporator 5, and an outdoor blower 6.
In the refrigerant circuit R, the high-pressure gas refrigerant discharged from the compressor 2 radiates heat in the condenser 3 and is liquefied and condensed, and the high-pressure refrigerant flowing out of the condenser 3 is depressurized by the expansion valve 4 and expands to become a low-pressure gas refrigerant. It becomes a refrigerant and flows into the evaporator 5. The low-pressure refrigerant that has flowed into the evaporator 5 is evaporated by exchanging heat with air passing through the air flow passage 13 of the air conditioning unit 10 (described later) in the evaporator 5, becomes a gas refrigerant, flows out of the evaporator 5, and is compressed. Return to machine 2.
Note that the evaporator 5 is provided with an evaporator temperature sensor 7 that detects the temperature of the refrigerant flowing into or out of the evaporator 5.

The heat medium circuit W includes a battery heat medium flow path 20 that circulates a heat medium to a battery 21 for driving, a motor heat medium flow path 30 that flows a heat medium to a motor 31 for driving, and an air conditioning unit 10 that will be described later. It includes a heater core 8 disposed in the air flow passage 13 and a heater core heat medium flow path 40 that allows a heat medium to flow through the PTC 41 as a heating device that heats the heater core 8.

The battery heat medium flow path 20 and the heater core heat medium flow path 40 are connected by a four-way valve V1. By controlling the four-way valve V1 by the control unit 100 described later, the battery heat medium flow path 20 and the heater core heat medium flow path 40 can be connected to each other or be independent flow paths. Similarly, the motor heat medium flow path 30 and the heater core heat medium flow path 40 are connected by a four-way valve V2, and by controlling the four-way valve V2 by the control unit 100, the motor heat medium flow path 30 and the heater core heat medium flow path are connected. The channels 40 can be interconnected channels or independent channels.

The battery heat medium flow path 20 can circulate a heat medium to the battery 21 by the first pump 22, warm up the battery 21, and recover waste heat from the battery 21. A battery temperature sensor 23 is provided upstream of the battery 21 to detect the temperature of the heat medium flowing into the battery 21.

The motor heat medium flow path 30 can circulate a heat medium to the motor 31 by the second pump 32, warm up the motor 31, and recover waste heat from the motor 31. A battery temperature sensor 23 is provided downstream of the motor 31 to detect the temperature of the heat medium flowing out of the motor 31.

The heater core heat medium flow path 40 circulates the heat medium through the PTC 41 and the heater core 8 by the third pump 42, and allows the heat medium heated by the PTC 41 to flow through the heater core 8, thereby passing through the air flow path 13 of the air conditioning unit 10. heating the air. A heater core temperature sensor 43 is provided between the PTC 41 and the heater core 8 to detect the temperature of the heat medium flowing out from the PTC 41 and flowing into the heater core 8.

The air conditioning unit 10 is provided with an outside air suction port and an inside air suction port for taking outside air or inside air into the air conditioning unit 10, and the suction port is provided with a suction switching damper 11 that switches opening and closing of each suction port. . On the air downstream side of the suction switching damper 11, a blower 12 is provided for feeding introduced outside air or inside air to the airflow passage 13.

An air mix damper 14 is provided between the evaporator 5 and the heater core 8 in the air flow passage 13 to adjust the proportion of the air that has flowed into the air flow passage 13 and passed through the evaporator 5 to be distributed to the heater core 8. It is being The air whose temperature is controlled in the air conditioning unit 10 is blown out into the vehicle interior through the air outlet 15.

FIG. 2 shows a schematic configuration of the control unit 100 of the vehicle air conditioner 1.
The control unit 100 functions as part of a vehicle control system of a vehicle in which the vehicle air conditioner 1 is mounted. The vehicle control system (not shown) includes various sensors and in-vehicle devices necessary for running the vehicle, and multiple in-vehicle ECUs (Electronic Control Units) that control these, and each in-vehicle ECU is connected to a CAN (Controller Area Network). They are communicably connected to each other via an in-vehicle network such as LIN (Local Interconnect Network), and transmit and receive information. Therefore, the control unit 100 is also connected to various in-vehicle ECUs, sensors, and in-vehicle devices via the in-vehicle network, and controls the refrigerant circuit R, heat medium circuit W, and air conditioning unit 10 in cooperation with the various in-vehicle ECUs.

The control unit 100 and each in-vehicle ECU include, for example, a processor such as a CPU (Central Processing Unit) or an MPU (Micro Processing Unit), an electric circuit, and a storage element such as a RAM (Random Access Memory) or a ROM (Read Only Memory). It is composed of Further, part or all of the operations executed by the in-vehicle ECU can also be realized by hardware such as an ASIC (application specific integrated circuit), an FPGA (field-programmable gate array), or a GPU (graphics processing unit).

As shown in FIG. 2, the evaporator temperature sensor 7, battery temperature sensor 23, motor temperature sensor 33, heater core temperature sensor 43, and operation unit 90 are connected to the input side of the control unit 100, and each of these sensors and The output of the operation unit 90 is input.

Further, on the output side of the control unit 100, a compressor 2, an outdoor blower 6, an expansion valve 4, a suction switching damper 11, a blower 12, an air mix damper 14, four-way valves V1, V2, a first pump 22, a second pump 32, a third pump 42, and a PTC 41 are connected. The control unit 100 controls these based on the output of each sensor, settings input through the operation unit 90, and information from other in-vehicle ECUs.
Note that in FIG. 2 and the following description, illustrations and descriptions of sensors and other detectors that are not directly related to this embodiment are omitted.

As shown in FIG. 2, in this embodiment, the control unit 100 includes a CPU (Central Processing Unit) 101, a ROM 103, a RAM 104, and a storage unit 102.
The CPU 101 executes various processes based on programs stored in the ROM 103. In this embodiment, the CPU 101 controls the refrigerant circuit R, the heat medium circuit W, and the air conditioning unit 10 by reading a program stored in the ROM 103 into a memory such as the RAM 104 and executing the program, thereby controlling a plurality of operation modes. At the same time, preheating control is performed to determine whether or not to preheat the heat medium in the heat medium circuit before switching the operation mode.

The operation modes executed by the control unit 100 include a so-called heating mode, a cooling mode, etc., as well as a special operation mode whose execution time is determined in advance. Examples of the special operation modes include forced cooling mode and forced ventilation mode. For example, the special operation mode is such that, during execution of the normal operation mode, a predetermined setting is executed automatically or triggered by the pressing of a switch by an occupant for a predetermined period of time, and then the original operation mode is executed. It can be set as follows.

Next, in the vehicle air conditioner 1 configured as described above, a process for determining whether or not to perform preheating control before switching the driving mode will be described using the flowchart of FIG. 3.
In the vehicle air conditioner 1, when switching to another operating mode manually or automatically during execution of any operating mode, preheating is performed to determine whether or not to preheat the heating medium in the heating medium circuit before switching the operating mode. Take control. In the following description, a case will be described in which, for example, the special operation mode is executed while the heating mode is being executed, and then the heating mode is executed again.

As shown in FIG. 3, when switching to the special operation mode is performed while the heating mode is being executed in the vehicle air conditioner 1 (YES in step S101), the control unit 100 sets the heating mode that is currently being executed. The obtained driving information is stored in the storage unit 102 (step S102). Here, whether or not the switching to the special driving mode is performed is determined manually, that is, depending on whether or not the occupant operates the operation unit 90, or automatically, that is, when the process related to the switching performed by the control unit 100 is started. The judgment is made based on whether or not it was done.

Further, the control unit 100 stores at least the blowout target temperature Tset of the air blown out from the blowout port 15 or the temperature of the heater core heat medium flow path 40 for realizing the blowout target temperature Tset as the operation information stored in the storage unit 102. The temperature of the heat medium (hereinafter referred to as target heat medium temperature TGTWO) is stored.

When the operation information set to the heating mode is stored in the storage unit 102, the control unit 100 starts executing the special operation mode (step S103), and stores the blowout target temperature set in the operation mode after returning, that is, the memory It is determined whether the blowout target temperature Tset stored in the unit 102 is higher than a predetermined threshold temperature Th (step S104), and if the blowout target temperature Tset is higher than the threshold temperature Th (YES in step S104). Then, preheating control is executed (step S105).

The reason why the target blowout temperature Tset and the threshold temperature Th are compared in step S104 is to determine whether preheating control is necessary by determining whether the operation mode after restoration is the heating mode. If the operating mode of the return degree is the heating mode, the temperature inside the vehicle, the blowout target temperature, and the heat medium temperature decrease while the special operation mode is being executed, and if you switch to the heating mode as it is, the heating medium will circulate through the heater core heat medium flow path 40. Since the temperature of the heating medium is low and the blowout target temperature Tset cannot be achieved, there is a possibility that the comfort of the occupants will be reduced.

When the preheating control process in step S105 is completed, the operation mode is returned to heating mode (step S106), and the process for determining whether or not to perform preheating control is ended.

Examples 1 to 3 relating to preheating control executed by the control unit 100 will be described below with reference to FIGS. 4 to 6. The control unit 100 can perform any of the processes in the following embodiments 1 to 3 as preheating control (step S105) in the flowchart of FIG.

(Example 1)
The flow of the preheating control process according to the first embodiment, which is executed by the control unit 100, will be described below using the flowchart of FIG. 4.
The control unit 100 detects the temperature of the heat medium flowing into the heater core 8 (hereinafter referred to as heater core water temperature) from the heater core temperature sensor 43 (step S201), and detects the target heat medium temperature TGTWO stored in the storage unit 102 or memory. The target heat medium temperature TGTWO obtained by calculation from the blowout target temperature Tset stored in the unit 102 is compared with the heater core water temperature (step S202).

If the target heat medium temperature TGTWO is higher than the heater core water temperature (YES in step S202), it is determined whether the PTC 41 is used to adjust the temperature of the battery 21 (step 203).

When the PTC 41 is not used to adjust the temperature of the battery 21 (NO in step S203), if the remaining capacity of the battery 21 is, for example, 50% or more (YES in step S204), the heater core heat medium flow path 40 is controlled by the PTC 41. Preheating of the heat medium circulating is started (step S205).

If the PTC 41 is used to adjust the temperature of the battery 21 (YES in step S203), and if the PTC 41 is not used to adjust the temperature of the battery 21 (NO in step S203), the remaining battery capacity is, for example, less than 50%. If so (NO in step S204), whether or not the waste heat of the motor 31 can be used, that is, the temperature of the heat medium flowing through the motor heat medium flow path 30 (hereinafter referred to as waste heat water temperature) is higher than the heater core water temperature. It is determined whether the temperature is also high (step S206). When the waste hot water temperature is higher than the heater core water temperature (YES in step S206), the heat medium (waste hot water) flowing through the motor heat medium flow path 30 is used to preheat the heat medium circulating through the heater core heat medium flow path 40. Alternatively, temperature maintenance is started (step S207).

In other words, the control unit 100 may drive the PTC 41 with the battery 21 to preheat the heat medium, for example, when the PTC 41 is used to adjust the temperature of the battery 21 or when the battery 21 does not have much remaining power. If it is not preferable, the heat medium is controlled to be preheated using a heat source other than the PTC 41.

When the target heat medium temperature TGTWO is lower than the heater core water temperature (NO in step S202) and when the waste heat water temperature is lower than the heater core water temperature (NO in step S206), the heat circulating in the heater core heat medium flow path 40 is The preheating control process ends without preheating the medium (step S208).

(Example 2)
The flow of the preheating control process according to the second embodiment, which is executed by the control unit 100, will be described below using the flowchart of FIG. 5.
The control unit 100 detects the heater core water temperature from the heater core temperature sensor 43 (step S301), and calculates the temperature obtained from the target heat medium temperature TGTWO stored in the storage unit 102 or the blowout target temperature Tset stored in the storage unit 102. The target heat medium temperature TGTWO and the heater core water temperature are compared (step S302).

If the target heat medium temperature TGTWO is higher than the heater core water temperature (YES in step S303), it is determined whether ΔT, which is the difference between the heater core water temperature and the target heat medium temperature TGTWO, is larger than a predetermined threshold Th1 ( Step S303). If ΔT is larger than the threshold Th1 (YES in step S303), it is determined whether the PTC 41 is used to adjust the temperature of the battery 21 (step 304).

When the PTC 41 is not used to adjust the temperature of the battery 21 (NO in step S304), if the remaining capacity of the battery 21 is, for example, 50% or more (YES in step S305), the heater core heat medium flow path 40 is controlled by the PTC 41. Preheating of the heat medium circulating is started (step S306).

If ΔT is smaller than the threshold Th1 (NO in step S303), if the PTC 41 is used to adjust the temperature of the battery 21 (YES in step S304), and if the PTC 41 is not used to adjust the temperature of the battery 21 ( (NO in step S304) However, if the remaining battery capacity is, for example, less than 50% (NO in step S305), it is determined whether the waste heat of the motor 31 can be used, that is, the waste hot water temperature is higher than the heater core water temperature. It is determined whether or not (step S307). When the waste hot water temperature is higher than the heater core water temperature, the heat medium (waste hot water) flowing through the motor heat medium flow path 30 is used to preheat or maintain the temperature of the heat medium circulating through the heater core heat medium flow path 40. (Step S308).

When the target heat medium temperature TGTWO is lower than the heater core water temperature (NO in step S302) and when the waste heat water temperature is lower than the heater core water temperature (NO in step S307), the heat circulating in the heater core heat medium flow path 40 is The preheating control process ends without preheating the medium (step S309).

(Example 3)
The flow of the preheating control process according to the second embodiment, which is executed by the control unit 100, will be described below using the flowchart of FIG. 6.
The control unit 100 detects the heater core water temperature from the heater core temperature sensor 43 (step S401), and determines whether ΔT, which is the difference between the heater core water temperature and the target heat medium temperature TGTWO, is within the range of a predetermined threshold Th2 to Th3. (Step S402).

If ΔT is not within the range from the threshold Th2 to Th3 (NO in step S402) and ΔT is larger than the predetermined threshold Th3 (YES in step S403), the PTC 41 is used to adjust the temperature of the battery 21. It is determined whether there is one (step 404).

If the PTC 41 is not used to adjust the temperature of the battery 21 (NO in step S404), and if the remaining capacity of the battery 21 is, for example, 50% or more (YES in step S405), the heater core heat medium flow path 40 is adjusted by the PTC 41. Preheating of the heat medium circulating is started (step S406).

If ΔT is not within the range from the threshold Th2 to Th3 (NO in step S402) and ΔT is smaller than the predetermined threshold Th3 (NO in step S403), the PTC 41 is used to adjust the temperature of the battery 21. (YES in step S404), and if the PTC 41 is not used to adjust the temperature of the battery 21 (NO in step S404), but the remaining battery capacity is, for example, less than 50% (NO in step S405), the motor It is determined whether the waste heat of No. 31 can be utilized, that is, whether the waste heat water temperature is higher than the heater core water temperature (step S407). When the waste hot water temperature is higher than the heater core water temperature, the heat medium (waste hot water) flowing through the motor heat medium flow path 30 is used to preheat or maintain the temperature of the heat medium circulating through the heater core heat medium flow path 40. (Step S408).

When the waste heat water temperature is lower than the heater core water temperature (NO in step S407), the preheating control process is ended without preheating the heat medium circulating through the heater core heat medium flow path 40 (step S309).

As described above, according to the vehicle air conditioner 1 according to the present embodiment, when the operation mode is switched, if the target temperature set in the operation mode after switching is higher than the threshold value, especially after the execution of the heating mode, the temporary Specifically, when there is a plan to execute an operation mode that is contradictory to the heating mode and return to the heating mode again, preheating control is performed to determine whether or not to preheat the heat medium flowing through the heater core before returning to the heating mode. By doing this, for example, it is possible to suppress a drop in the temperature of the heat medium and ensure quick heating immediately after returning to heating mode, improving passenger comfort even immediately after switching the operating mode. can be done.
In addition, by selecting either PTC or motor waste heat when preheating the heat medium depending on the remaining battery level, waste heat can be used effectively and power consumption in the vehicle can be reduced. .

Although the embodiments of the present invention have been described above in detail with reference to the drawings, the specific configuration is not limited to these embodiments, and the design may be changed without departing from the gist of the present invention. Even if there is, it is included in the present invention. In addition, the above-described embodiments can be combined by utilizing each other's technologies unless there is a particular contradiction or problem in their purpose, structure, etc.

1: Vehicle air conditioner,
2: Compressor, 3: Condenser, 4: Expansion valve, 5: Evaporator, 6: Outdoor blower,
7: Evaporator temperature sensor, 8: Heater core,
10: air conditioning unit, 11: suction switching damper, 12: blower, 13: air flow path, 14: air mix damper, 15: outlet,
20: battery heat medium flow path, 21: battery, 23: battery temperature sensor,
30: Motor heat medium flow path, 31: Motor, 33: Motor temperature sensor,
40: Heater core heat medium flow path, 43: Heater core temperature sensor,
90: Operation unit,
100: Control unit, 101: CPU, 102: Storage unit, 103: ROM, 104: RAM,
R: refrigerant circuit, V1, V2: four-way valve, W: heat medium circuit TGTWO: target heat medium temperature, Tset: blowout target temperature,
Th: threshold temperature, Th1: threshold, Th2: threshold, Th3: threshold

Claims (5)

a heat medium circuit in which a heat medium heated or cooled by heat exchange with a heat source circulates;
an air conditioning unit in which a heat exchanger for exchanging heat between the heat medium circulating in the heat medium circuit and air is disposed in an air flow passage, and blows air temperature-controlled by the heat exchanger into a vehicle interior;
a control unit that controls the heat source, the heat medium circuit, and the air conditioning unit to switch and execute a plurality of operation modes;
When switching the operation mode, the control unit determines whether or not to preheat the heat medium of the heat medium circuit before switching the operation mode, if a target temperature set for the operation mode after switching is higher than a threshold value. A vehicle air conditioner that performs preheating control. In the preheating control, the control unit includes:
The vehicle air conditioner according to claim 1, wherein the heat medium is preheated by the heat source when the temperature of the heat medium corresponding to the target temperature is higher than the temperature of the heat medium circulating in the heat medium circuit. The heat medium circuit is provided with a heating device that heats the heat medium,
In the preheating control, the control unit includes:
The heating is performed when the temperature of the heat medium corresponding to the target temperature is higher than the temperature of the heat medium circulating in the heat medium circuit, and the remaining capacity of the battery mounted on the vehicle is equal to or higher than a predetermined value. The vehicle air conditioner according to claim 1, wherein the heating medium is preheated by the device. The vehicle air conditioner according to claim 3, wherein the control unit preheats the heat medium by the heat source when the heating device is used to adjust the temperature of the battery. The vehicle air conditioner according to any one of claims 1 to 3, wherein the heat source is a refrigerant circulating in a refrigerant circuit or an in-vehicle device.

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