JP5999349B2 - Air conditioner for vehicles - Google Patents

Description

  The present invention relates to a vehicle air conditioner.

  Conventionally, as a vehicle air conditioner, a heat pump system (vapor compression refrigeration cycle) having a compressor, an indoor condenser, an outdoor condenser, an indoor evaporator, and a decompression unit is known. In an electric vehicle, unlike an engine vehicle, heat from a drive source cannot be used for heating, and thus such a heat pump system is employed (see, for example, Patent Document 1). In the vehicle heat pump system described in Patent Document 1, during cooling operation, the heat medium discharged from the compressor dissipates heat in the outdoor exchanger, and the heat medium evaporates in the indoor evaporator, thereby cooling the wind passing through the evaporator. . On the other hand, during the heating operation, the heat medium discharged from the compressor radiates heat with the indoor condenser, and the heat passing through the indoor condenser is warmed by this heat radiation.

  In such a heat pump system, the outdoor condenser may be frosted during heating operation. In this case, if the defrosting operation is performed during the operation, the air conditioning cannot be used during that time, and the passenger may feel inconvenience. Therefore, the defrosting operation is performed during charging.

Japanese Patent No. 3379155

  However, in the invention described in Patent Document 1, when charging is performed, defrosting operation can be performed to perform defrosting. However, if charging is not performed, the defrosting operation cannot be performed. That is, a situation where the defrosting cannot be performed efficiently and the frost remains forever can be considered.

  Accordingly, an object of the present invention is to solve the above-described problems of the prior art, and to provide a vehicle air conditioner that can efficiently perform a defrosting operation without performing charging.

  The vehicle air conditioner of the present invention includes a compression unit that compresses a heat medium, a decompression unit that depressurizes the heat medium, a heat exchanger that performs heat exchange between the heat medium and air, and the heat medium. An air conditioner for an electric vehicle, comprising: a control means for controlling air conditioning in the vehicle interior, wherein the control means is attached to an outdoor heat exchanger that exchanges heat with outdoor air in the heat exchanger. When it has been determined that frost formation has occurred by the frost determination unit, the vehicle is stopped and the air conditioner is turned off, and then again When the vehicle is in a running state and the air conditioner is turned on, heat is exchanged between the outdoor heat exchanger and outdoor air by passing the compressed heat medium from the compression means through the outdoor heat exchanger. And performing a defrosting operation to dissipate heat. When it is detected that the outdoor heat exchanger that exchanges heat with outdoor air in the heat exchanger is frosted, the vehicle stops and the air conditioner is turned off. By performing the defrosting operation when it becomes, the defrosting operation can be performed without charging. In addition, by performing the defrosting operation immediately after the start of traveling, it is possible to immediately recover the heating performance, which is efficient. Note that the stop of the vehicle does not include a temporary stop of the vehicle, but means a stop of the driving state of the vehicle (for example, parking).

  Preferably, the control means determines whether or not the cooling operation is performed when the vehicle is in a traveling state again and the air conditioner is turned on again, and the defrosting operation is not performed during the cooling operation. This is because defrosting can be performed during the cooling operation.

  Preferably, the control means immediately performs the defrosting operation when a heating operation command is input by an occupant when the vehicle is running again and the air conditioner is turned on again. This is because the heating operation can be efficiently performed by performing the defrosting operation prior to the start of the heating operation.

  Temperature detecting means for detecting the temperature of the heat medium passing through the outdoor heat exchanger, and when the temperature detected by the temperature detecting means becomes larger than a predetermined value during the defrosting operation, the defrosting operation is performed. Is preferably stopped. This is because when the temperature of the heat medium passing through the outdoor heat exchanger becomes higher than a predetermined value, it can be determined that the defrosting is completed.

  As a preferred embodiment of the present invention, the defrosting operation is stopped when a predetermined time elapses after the start.

  According to the vehicle air conditioner of the present invention, even if charging is not performed, the defrosting can be surely performed at the next operation when frost is formed, and an excellent effect of being efficient can be obtained.

The schematic diagram of the heat pump system concerning the vehicle air conditioner of this embodiment. The schematic diagram for demonstrating the air-conditioning panel of this embodiment. The schematic diagram for demonstrating the drive of the heat pump system at the time of air_conditioning | cooling of the vehicle air conditioner of this embodiment. The schematic diagram for demonstrating the drive of the heat pump system at the time of the heating of the vehicle air conditioner of this embodiment. The schematic diagram for demonstrating the drive of the heat pump system at the time of the defrost of the vehicle air conditioner of this embodiment. The flowchart for demonstrating frost inversion in the vehicle air conditioner of this embodiment. The flowchart for demonstrating the defrost control in the vehicle air conditioner of this embodiment.

  First, the heat pump system concerning the vehicle air conditioner of this embodiment is demonstrated using FIG.

  The vehicle air conditioner I has a heat pump system 1. The heat pump system 1 includes an electric compressor (compression means) 11, an indoor condenser (heat exchanger) 12, an outdoor condenser (heat exchanger) 13, an evaporator (heat exchanger) 14, an accumulator 15, and a first expansion valve (decompression means). 21 and a second expansion valve (decompression means) 22, which are connected by a pipe 16 constituting a flow path of the heat medium. As will be described in detail later, the heat pump system 1 includes a cooling path configured by connecting an electric compressor 11, an indoor condenser 12, an outdoor condenser 13, a second expansion valve 22, and an accumulator 15 in this order by a pipe 16. Moreover, the heat pump system 1 includes a heating path configured by connecting an electric compressor 11, an indoor condenser 12, a first expansion valve 21, an outdoor condenser 13, and an accumulator 15 in this order by a pipe 16.

  The vehicle air conditioner I includes a control unit (control means) 10 for driving the heat pump system 1.

  The control unit 10 includes a heat medium temperature sensor (temperature detection means) 31 that detects the temperature of the heat medium that passes through the outdoor condenser 13, and an outdoor temperature sensor (temperature detection means) 32 that detects an outdoor temperature provided in the vehicle body. Is provided.

  When the air compressor operation instruction is input by the occupant, the electric compressor 11 that receives power supply from the driving secondary battery starts to be driven by the control unit 10 and compresses the heat medium into a high temperature and high pressure state.

  The indoor condenser 12 performs heat exchange between the heat medium and the air in the passenger compartment. The indoor condenser 12 is provided in the air conditioning housing 17. In the air conditioning housing 17, a blower fan (not shown), the above-described evaporator 14, air mix damper 18, and PTC heater 19 are provided. The indoor condenser 12 is provided on the downstream side of the evaporator 14 in the air conditioning housing 17. In addition, the air mix damper 18 is provided between the evaporator 14 and the indoor condenser 12 and is configured so that the open / close state differs between heating and cooling. The PTC heater 19 is provided on the downstream side of the indoor condenser 12. The heat medium that has passed through the indoor condenser 12 is sent to the outdoor condenser 13 via the pipe 16.

  A pipe 16 between the indoor capacitor 12 and the outdoor capacitor 13 is provided with a first expansion valve 21 and a two-way electromagnetic valve 23 provided in parallel to the first expansion valve 21. The opening and closing of the two-way solenoid valve 23 is controlled by the control unit 10. When the two-way solenoid valve 23 is turned on, the heat medium flows through the first expansion valve 21 side, and when the two-way solenoid valve 23 is turned off, the heat medium flows through the two-way solenoid valve 23 side. Flowing.

  The outdoor condenser 13 performs heat exchange between the heat medium and the air outside the passenger compartment. A three-way solenoid valve 24 is provided on the downstream side of the outdoor condenser 13, and the flow path through which the heat medium passes can be changed by switching the three-way solenoid valve 24 during cooling and heating. That is, the heat medium that has passed through the outdoor condenser 13 is sent to the evaporator 14 during cooling via the pipe 16a as will be described in detail later, and is sent to the accumulator 15 via the pipe 16b during heating. In the present embodiment, the switching operation of the three-way solenoid valve 24 is controlled by the control unit 10. That is, when the control unit 10 controls the three-way electromagnetic valve 24 to be in the on state, the heat medium flows through the pipe 16a, and when the three-way electromagnetic valve 24 is controlled to be in the off state, the heat medium flows through the pipe 16b.

  A second expansion valve 22 is provided between the three-way solenoid valve 24 and the evaporator 14. The second expansion valve 22 functions as a decompression unit, and expands and decompresses the heat medium to lower the heat medium temperature.

  The evaporator 14 performs heat exchange between the heat medium and the air in the passenger compartment, and cools the air sent to the passenger compartment.

  The accumulator 15 functions as a heat medium reservoir.

  Moreover, the control part 10 acquires the air-conditioning instruction | indication from a passenger | crew from the air-conditioning panel P shown in FIG. The air conditioning panel P is provided, for example, on an instrument panel of a vehicle. The air conditioning panel shown in FIG. 2 is provided with a mode dial 41, a blower fan dial 42, and a temperature adjustment dial 43 from the left in the figure, and an occupant gives these air conditioning instructions by setting these dials.

  The mode dial 41 is for the occupant to select the balloon mode. As the blowing mode, for example, there are a defroster mode 41a in which the occupant operates the defroster in order to prevent the windshield from condensing, a foot mode 41b in which the conditioned air is sent only from the foot duct, and the occupant sets the dial to each mode. You can select the balloon mode with.

  The central blower fan dial 42 is for the occupant to set the amount of air blown from the blower fan. When AUTO of the blower fan dial 42 is selected, the air flow rate is automatically set to the auto mode (the mode in which the blowout amount of the sending means is automatically set). Other than AUTO in the auto mode, the occupant can specify the air flow rate by specifying the air flow rate from 0 to the maximum and adjusting the dial. An A / C (air conditioner) switch 44 is provided inside the blower fan dial 42. The A / C switch 44 is an A / C on / off switch, and when pressed, the A / C operates.

  The temperature adjustment dial 43 is for setting the temperature of the conditioned air blown into the passenger compartment by the occupant. When the temperature adjustment dial 43 indicates the H side, warm air is set (heating setting), and when the temperature adjustment dial indicates the C side, cold air is set (cooling setting). A maximum switch 45 is provided inside the temperature adjustment dial 43. When the occupant presses the max switch 45, the air conditioning is set to a max mode (mode in which the cooling or heating function of the vehicle is set to the maximum) that exhibits the maximum performance, assuming that the max switch 45 is on.

  The control part 10 operates said heat pump system 1 according to the air-conditioning instruction | indication from the passenger | crew by each dial of these air-conditioning panels P. FIG. For example, when the temperature adjustment dial 43 is set to the cooling side and the A / C switch 44 is pressed by the occupant, the control unit 10 operates the cooling operation by the heat pump system 1 assuming that the cooling instruction is input. When the temperature adjustment dial 43 is set to the heating side, the control unit 10 operates the heating operation in the heat pump system 1 assuming that the heating instruction is input.

  The operation of the heat pump system during cooling will be described with reference to FIG.

  When the temperature adjustment dial 43 is set to the cooling side by the occupant, a cooling instruction is input to the control unit 10. The control unit 10 controls the two-way solenoid valve 23 to turn off and the three-way solenoid valve 24 to turn on, and operates the electric compressor 11.

  From the electric compressor 11, the heat medium compressed to a high temperature and high pressure is input to the indoor condenser 12 through the pipe 16. Since the indoor condenser 12 does not operate during cooling, the heat medium simply passes through the indoor condenser 12. Note that the air mix damper 18 is set in an open / closed state so as to face the indoor condenser 12 during cooling.

  The heat medium that has passed through the indoor condenser 12 flows through the two-way electromagnetic valve 23 side and is input to the outdoor condenser 13 because the two-way electromagnetic valve 23 is in the OFF state. The heat medium input to the outdoor condenser 13 dissipates heat by exchanging heat with the outdoor air using the outdoor condenser 13, and the heat medium temperature is slightly lowered.

  Next, since the three-way solenoid valve 24 is in the ON state, the heat medium from the outdoor condenser 13 is input to the second expansion valve 22 and the heat medium is depressurized. The temperature of the decompressed heat medium also decreases.

  The heat medium from the second expansion valve 22 is input to the evaporator 14. In the evaporator 14, the heat medium exchanges heat with room air and absorbs heat from the room air to cool the room air. This cooled room air is supplied to the passenger compartment as cold air.

  The heat medium output from the evaporator 14 is input to the accumulator 15, and then input to the electric compressor 11 and compressed again, and the heat medium flows through the flow path as described above.

  Next, the operation of the heat pump system during heating will be described with reference to FIG.

  When the temperature control dial 43 is set to the heating side by the passenger and the heating instruction is input to the control unit 10, the control unit 10 controls the two-way solenoid valve 23 to be turned on and the three-way solenoid valve 24 to be turned off. And the electric compressor 11 is operated.

  From the electric compressor 11, the heat medium compressed to a high temperature and high pressure is input to the indoor condenser 12 through the pipe 16. The indoor condenser 12 operates during heating, and the heat medium exchanges heat with the air in the passenger compartment in the indoor condenser 12 to radiate heat. The radiated air is further heated by passing through the PTC heater 19, and the heated indoor air is supplied as warm air into the vehicle interior. In this case, the open / close state is set so that the air mix damper 18 does not face the indoor condenser 12.

  The heat medium that has passed through the indoor condenser 12 flows through the first expansion valve 21 side because the two-way solenoid valve 23 is in the ON state, and is depressurized to decrease the temperature. The decompressed heat medium is input to the outdoor capacitor 13. The heat medium flowing into the outdoor condenser 13 absorbs heat by exchanging heat with outdoor air in the outdoor condenser 13, and the heat medium temperature rises slightly.

  Next, since the three-way solenoid valve 24 is in the OFF state, the heat medium from the outdoor condenser 13 flows into the accumulator 15, and then flows into the electric compressor 11 and is compressed again. Circulate.

  When the heating operation is performed, it is conceivable that the outdoor condenser 13 is frosted in relation to the outside air temperature. The air conditioner of the present embodiment has a defrosting operation mode for removing frost formation on the outdoor condenser 13.

  The defrosting operation will be described with reference to FIG.

  During the defrosting operation, both the three-way solenoid valve 24 and the two-way solenoid valve 23 are turned off. The compressed heat medium discharged from the electric compressor 11 passes through the indoor condenser 12. Then, the heat medium passes through the outdoor capacitor 13 through the two-way electromagnetic valve 23 in the off state while being in a high compression and high temperature state. Then, heat exchange is performed in the outdoor capacitor 13, and heat radiation is performed in the outdoor capacitor 13, so that frost attached to the outdoor capacitor 13 can be removed. Then, the heat medium whose temperature has decreased due to heat dissipation passes through the three-way electromagnetic valve 24 in the off state, is input to the accumulator 15, and is input again to the electric compressor 11. In this way, frost formation on the outdoor capacitor 13 can be removed.

  Hereinafter, the defrost control by the control part 10 is demonstrated in detail.

  When a heating operation command is input to the control unit 10 during vehicle operation, a frost determination unit (frost determination unit) (not shown) of the control unit 10 performs frost determination. The heat medium temperature is acquired from the heat medium temperature sensor 31 that detects the temperature of the heat medium that passes through the outdoor condenser 13, and the outdoor temperature is acquired from the outdoor temperature sensor 32 that detects the outdoor temperature provided in the vehicle body. And the frost determination part of the control part 10 is when the heating medium temperature is below a predetermined value, and the difference of a heating medium temperature and outdoor temperature is more than a predetermined value, and heating operation is performed ( That is, when the heating instruction is input to the control unit 10, it is determined that the outdoor condenser 13 is frosted. The control unit 10 records this determination even when the vehicle is stopped and the air conditioner is turned off to end the control once.

  And the control part 10 will be started if a vehicle stops and an air conditioner is made into an OFF state, and a vehicle will be in a driving | running state again after that and an air conditioner is turned on. When the occupant inputs a heating operation command to the control unit 10 in this state, the control unit 10 determines whether the blowing mode is not the defroster mode and the blower fan is AUTO if there is a record of frost formation, When these conditions are satisfied, the defrosting operation is performed.

  During the defrosting operation, the control unit 10 obtains the temperature of the heat medium passing through the outdoor condenser 13 from the heat medium temperature sensor 31, and determines whether or not the temperature of the outdoor condenser 13 is equal to or higher than the predetermined value, that is, whether the frost has been removed. To do. Moreover, the control part 10 sets a timer with the start of a defrost operation, and performs this defrost control for predetermined time (for example, 10 minutes). This predetermined time is set to a time that can be removed if it is ordinary frost. And the control part 10 determines whether the temperature of the heat medium which passes the outdoor capacitor | condenser 13 becomes more than predetermined value, or predetermined time passes, and when either conditions are satisfy | filled, defrost operation is performed. Stop. Then, normal control, that is, normal heating operation is started.

  Thus, in the present embodiment, the defrosting operation can be performed without charging. In addition, by performing the defrosting operation immediately after the start of traveling, it is possible to immediately recover the heating performance, which is efficient. When the blowing mode is the defroster mode and the blower fan is not in the auto mode, the passenger's request can be satisfied by giving priority to the passenger's setting.

  Such control by the control unit 10 will be described with reference to FIGS.

  As shown in FIG. 6, a control part performs control for normal heating operation by step S1. In step S2, the frost determination unit of the control unit periodically performs the frost determination described above. If it is determined that frost formation has occurred, the process proceeds to step S3. Until it determines with having formed frost, a control part returns to step S1, and repeats frost determination. In step S3, the control unit turns on the frost flag.

  Thereafter, after the vehicle is stopped and the air conditioner is turned off, when the vehicle is in the running state again and the air conditioner is turned on, the control unit is activated to start the control shown in FIG. In step S11, the vehicle starts traveling, and proceeds to step S12. When the heating operation is started in step S12, the process proceeds to step S13. In step S13, the control unit determines whether or not the frosting flag is on. If the frosting flag is off, the process ends. If the frosting flag is on, the process proceeds to step S14.

  In step S14, the control unit 10 determines whether or not the blowing mode is the defroster mode and the blower fan is AUTO. If the blowing mode is not the defroster mode and the blower fan is set to AUTO (YES), the process proceeds to step S15. When the blowing mode is the defroster mode or the blower fan is not set to AUTO (NO), the process proceeds to step S18.

  In step S15, a control part performs a defrost operation and progresses to step S16. In step S16, the control unit determines whether a predetermined time has elapsed since the start of the defrosting operation or whether the frost has been removed. If either condition is satisfied, the process proceeds to step S17. In addition, when frost is left at the end of the defrosting operation, the frosting flag is kept on, but when it is completely defrosted, the frosting flag is turned off. When neither condition is satisfied, the process returns to step S15 to perform the defrosting operation.

  In step S17, the control unit stops the defrosting operation. Thereby, in step S18, a control part performs normal control, ie, normal heating operation. Note that the frosting flag is turned off once during normal heating operation, and frosting determination is performed again during heating. Thereafter, the control unit stops the control by stopping the vehicle and turning off the air conditioner.

  Thus, in this embodiment, defrosting operation can be performed without performing charging, and defrosting can be performed efficiently. In addition, by performing the defrosting operation immediately after the start of traveling, it is possible to immediately recover the heating performance, which is efficient. Further, when the blowing mode is the defroster mode, if the blower fan is not set to AUTO, the passenger's request can be satisfied by giving priority to the passenger's setting.

  In the present embodiment, after the vehicle is stopped and the air conditioner is turned off, the control unit 10 starts the defrosting operation with the start of the heating operation immediately after the vehicle is turned on again and the air conditioner is turned on. However, it is not limited to this. The control unit 10 may start the defrosting operation immediately after the vehicle is again in the running state and the air conditioner is turned on. In addition, immediately after the control unit 10 travels again and the air conditioner is turned on, it is determined whether or not the cooling operation is performed. If the cooling operation is not performed, the defrosting operation is started. You may comprise as follows. This is because frost formation on the outdoor condenser is removed during the cooling operation.

  In the present embodiment, the control unit 10 does not perform the defrosting operation at the time of charging. For example, the controller 10 performs the defrosting operation at the time of normal charging. You may comprise so that it can defrost completely by performing defrost operation again immediately after driving | running | working state and an air conditioner will be in an ON state. Even in this case, it is possible to immediately recover the heating performance by performing the defrosting operation again immediately after the start of traveling, which is efficient.

  In the present embodiment, an electric vehicle has been described as an example, but the present invention is not limited to this. It may be an electric vehicle such as a plug-in hybrid vehicle.

  The vehicle air conditioner of the present invention can efficiently perform a defrosting operation. Therefore, it can be used in the vehicle manufacturing field.

DESCRIPTION OF SYMBOLS 1 Heat pump system 10 Control part 11 Electric compressor 12 Indoor condenser 13 Outdoor condenser 14 Evaporator 15 Accumulator 16 Piping 17 Air conditioning housing 18 Air mix damper 19 Heater 21 First expansion valve 22 Second expansion valve 23 Two-way solenoid valve 24 Three-way solenoid valve I Vehicle air conditioner

Claims (5)

Compression means for compressing the heat medium;
Decompression means for decompressing the heat medium;
A heat exchanger for exchanging heat between the heat medium and air;
Control means for controlling the air conditioning of the passenger compartment using the heat medium, and an air conditioner for an electric vehicle,
The control means includes
Frost determination means for determining whether or not frost is generated in an outdoor heat exchanger that performs heat exchange with outdoor air among the heat exchangers,
When it is determined by the frost determination means that the frost is generated, the compression means is used when the vehicle is stopped again and the air conditioner is turned on after the vehicle is stopped and the air conditioner is turned off. A vehicle air conditioner that performs a defrosting operation in which heat is exchanged between the outdoor heat exchanger and outdoor air to dissipate heat by passing the compressed heat medium from the outdoor heat exchanger through the outdoor heat exchanger. .   The control means determines whether or not a cooling operation is performed when the vehicle is in a running state again and the air conditioner is turned on again, and the defrosting operation is not performed during the cooling operation. Item 2. The vehicle air conditioner according to Item 1.   3. The control device according to claim 1, wherein when the vehicle is in a running state again and the air conditioner is turned on again, the control means immediately performs the defrosting operation when a heating operation command is input by a passenger. The vehicle air conditioner described. Comprising temperature detecting means for detecting the temperature of the heat medium passing through the outdoor heat exchanger;
The said defrost operation is stopped when the temperature detected by the said temperature detection means becomes larger than a predetermined value during the said defrost operation. Vehicle air conditioner.   The vehicle air conditioner according to any one of claims 1 to 4, wherein the defrosting operation is stopped when a predetermined time has elapsed after the start.

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