JP6807710B2 - Vehicle air conditioner - Google Patents

Description

The present invention relates to a heat pump type air conditioner for air-conditioning the interior of a vehicle.

Due to the emergence of environmental problems in recent years, hybrid vehicles and electric vehicles have become widespread. As an air conditioner that can be applied to such a vehicle, a compressor that compresses and discharges the refrigerant, a radiator that is provided on the vehicle interior side to dissipate the refrigerant, and a radiator that is provided on the vehicle interior outside are provided. A heating mode has been developed in which an outdoor heat exchanger that absorbs heat from the refrigerant is provided, the refrigerant discharged from the compressor is dissipated in the radiator, and the refrigerant dissipated in this radiator is absorbed in the outdoor heat exchanger. (See, for example, Patent Document 1).

Further, in the heating mode, since the outdoor heat exchanger absorbs heat from the outside air, frost is formed on the outdoor heat exchanger. When frost grows on the outdoor heat exchanger, the heat absorption capacity from the outside air is significantly reduced, so it is necessary to stop the compressor or defrost the outdoor heat exchanger, but in that case it is blown into the passenger compartment. Since the air temperature will drop and comfort will be impaired, defrosting and shutdown should be minimized.

For that purpose, highly accurate frost formation determination is required. In the above publication, the refrigerant evaporation temperature TXObase and the refrigerant evaporation pressure PXObase of the outdoor heat exchanger at the time of no frost are estimated based on the outside air temperature and the vehicle speed, and are actually used. When the refrigerant evaporation temperature TXO and the refrigerant evaporation pressure PXO of the above are lower than those and the difference ΔTXO and ΔPXO are equal to or more than a predetermined value, it is determined that frost formation is progressing in the outdoor heat exchanger. It was.

Japanese Unexamined Patent Publication No. 2014-94676

However, in reality, due to variations in sensors and other parts for detecting the outside air temperature and the like, an error occurs in the estimated values of the refrigerant evaporation temperature TXObase and the refrigerant evaporation pressure PXObase of the outdoor heat exchanger when there is no frost. This error is an error toward the side where frost is not detected, that is, an error in which the refrigerant evaporation temperature TXObase and the refrigerant evaporation pressure PXObase of the outdoor heat exchanger at the time of no frost are lower than the actual refrigerant evaporation temperature TXO and the refrigerant evaporation pressure PXO. If this is the case, there is a problem that the outdoor heat exchanger cannot be detected even though the frost formation is progressing.

The present invention has been made to solve the above-mentioned conventional technical problems, and is an air conditioner for vehicles that can accurately detect frost formation in an outdoor heat exchanger even if parts vary. The purpose is to provide.

The vehicle air conditioner according to claim 1 has a compressor that compresses the refrigerant, an air flow passage through which the air supplied to the vehicle interior flows, and air that dissipates the refrigerant and supplies the air to the vehicle interior from the air flow passage. It is equipped with a radiator for heating, an outdoor heat exchanger provided outside the vehicle interior to absorb the refrigerant, and a control device. With this control device, at least the refrigerant discharged from the compressor is dissipated by the radiator. After depressurizing the radiated refrigerant, heat is absorbed by the outdoor heat exchanger to heat the passenger compartment, and the refrigerant evaporation temperature TXO of the outdoor heat exchanger and the refrigerant evaporation of the outdoor heat exchanger when there is no frost. Based on the temperature TXObase, the frost on the outdoor heat exchanger is determined, and the control device exchanges the outdoor heat at the time of no frost based on the environmental conditions and / or the index indicating the operating condition. In addition to estimating the refrigerant evaporation temperature TXObase of the vessel, the side that does not detect frost formation between the refrigerant evaporation temperature TXObase of the outdoor heat exchanger and the refrigerant evaporation temperature TXO of the outdoor heat exchanger at the time of no frost at the initial stage of startup. When there is an error LRN to, the error LRN is reduced or canceled, and the refrigerant evaporation temperature TXObase of the outdoor heat exchanger at the time of no frost is corrected.

The vehicle air conditioner according to claim 2 has a compressor that compresses the refrigerant, an air flow passage through which the air supplied to the vehicle interior flows, and air that dissipates the refrigerant and supplies the air to the vehicle interior from the air flow passage. It is equipped with a radiator for heating, an outdoor heat exchanger provided outside the vehicle interior to absorb the refrigerant, and a control device. With this control device, at least the refrigerant discharged from the compressor is dissipated by the radiator. After depressurizing the radiated refrigerant, heat is absorbed by the outdoor heat exchanger to heat the passenger compartment, and the refrigerant evaporation pressure PXO of the outdoor heat exchanger and the refrigerant evaporation of the outdoor heat exchanger when there is no frost. Based on the pressure PXObase, the frost formation on the outdoor heat exchanger is determined, and the control device exchanges outdoor heat in the absence of frost based on the environmental conditions and / or the index indicating the operating condition. The side that does not detect frost formation between the refrigerant evaporation pressure PXObase of the outdoor heat exchanger and the refrigerant evaporation pressure PXO of the outdoor heat exchanger at the initial stage of startup while estimating the refrigerant evaporation pressure PXObase of the vessel. When there is an error LRN to, the error LRN is reduced or canceled, and the refrigerant evaporation pressure PXObase of the outdoor heat exchanger at the time of no frost is corrected.

In the vehicle air conditioner according to the third aspect of the present invention, in each of the above inventions, the control device has a refrigerant evaporation temperature TXO of the outdoor heat exchanger lower than the refrigerant evaporation temperature TXObase of the outdoor heat exchanger when there is no frost. When the difference ΔTXO is equal to or higher than a predetermined value for a predetermined time, or when the refrigerant evaporation pressure PXO of the outdoor heat exchanger is lower than the refrigerant evaporation pressure PXObase of the outdoor heat exchanger when there is no frost, the difference thereof When the state in which the difference ΔPXO is equal to or greater than a predetermined value continues for a predetermined time, it is determined that the outdoor heat exchanger has been frosted.

In the vehicle air conditioner according to the fourth aspect of the present invention, in the above invention, the control device calculates the difference ΔTXO or the difference ΔPXO a plurality of times within a predetermined period at the initial stage of activation, and sets the difference ΔTXO as the largest difference within the predetermined period. It is determined whether or not the difference ΔPT from the smallest difference ΔTXO or the difference ΔPP between the largest difference ΔPXO and the smallest difference ΔPXO within a predetermined period is within a predetermined value, and if it is within a predetermined value, the predetermined value is determined. It is characterized in that the error LRN is determined based on a plurality of differences ΔTXO within a period or a plurality of differences ΔPXO within the predetermined period.

In the vehicle air conditioner according to the fifth aspect of the present invention, in the above invention, when the control device does not have a difference ΔPT or a difference ΔPP within a predetermined value within a predetermined timeout period, when there is no frost due to an error LRN. It is characterized in that the correction of the refrigerant evaporation temperature TXObase of the outdoor heat exchanger or the correction of the refrigerant evaporation pressure PXObase of the outdoor heat exchanger at the time of no frost due to the error LRN is not performed.

In the vehicle air conditioner of the invention of claim 6, when the control device determines that the outdoor heat exchanger has frosted, the compressor is stopped or the outdoor heat exchanger is frosted. It is characterized by performing a predetermined defrosting operation for removing.

According to the invention of claim 1 or 2, at least the refrigerant discharged from the compressor is radiated by the radiator, the radiated refrigerant is depressurized, and then the heat is absorbed by the outdoor heat exchanger to create the vehicle interior. Along with heating, based on the refrigerant evaporation temperature TXO of the outdoor heat exchanger and the refrigerant evaporation temperature TXObase of the outdoor heat exchanger when there is no frost, or based on the refrigerant evaporation pressure PXO of the outdoor heat exchanger and no frost. In the vehicle air conditioner that determines frost formation on the outdoor heat exchanger based on the refrigerant evaporation pressure PXObase of the outdoor heat exchanger at that time, the control device is an index indicating environmental conditions and / or operating conditions. Based on, the refrigerant evaporation temperature TXObase of the outdoor heat exchanger at the time of no frost or the refrigerant evaporation pressure PXObase of the outdoor heat exchanger at the time of no frost is estimated, and at the initial stage of startup, the outdoor at the time of no frost. Between the refrigerant evaporation temperature TXObase of the heat exchanger and the refrigerant evaporation temperature TXO of the outdoor heat exchanger, or between the refrigerant evaporation pressure PXObase of the outdoor heat exchanger and the refrigerant evaporation pressure PXO of the outdoor heat exchanger when there is no frost. If there is an error LRN to the side that does not detect frost formation between, the refrigerant evaporation temperature TXObase of the outdoor heat exchanger at the time of no frost formation or no frost formation in the direction of reducing or canceling this error LRN. Since the refrigerant evaporation pressure PXObase of the outdoor heat exchanger at the time is corrected, the refrigerant evaporation temperature TXObase of the outdoor heat exchanger at the time of no frost estimated due to the variation of parts, or the relevant at the time of no frost. Even if an error LRN occurs between the refrigerant evaporation pressure PXObase of the outdoor heat exchanger and the actual refrigerant evaporation temperature TXO of the outdoor heat exchanger or the refrigerant evaporation pressure PXO, it is reduced or canceled to reduce or cancel it outdoors. It will be possible to accurately detect the progress of frost formation in the heat exchanger.

Then, when the control device determines that the outdoor heat exchanger has frosted as in claim 6, the compressor is stopped or a predetermined defrosting operation for removing the frost on the outdoor heat exchanger. By executing the above, it becomes possible to appropriately protect the equipment and defrost the outdoor heat exchanger to ensure the comfort in the passenger compartment.

Further, as in the invention of claim 3, in the control device, the refrigerant evaporation temperature TXO of the outdoor heat exchanger is lower than the refrigerant evaporation temperature TXObase of the outdoor heat exchanger when there is no frost, and the difference ΔTXO is equal to or more than a predetermined value. When the state continues for a predetermined time, or the refrigerant evaporation pressure PXO of the outdoor heat exchanger is lower than the refrigerant evaporation pressure PXObase of the outdoor heat exchanger when there is no frost, the difference ΔPXO becomes equal to or more than the predetermined value. If the state continues for a predetermined time, it is determined that the outdoor heat exchanger has been frosted, thereby eliminating erroneous judgment due to the influence of disturbance, etc., and accurately detecting the progress of frost formation in the outdoor heat exchanger. Will be able to.

In this case, as in the invention of claim 4, the difference ΔTXO or the difference ΔPXO is calculated a plurality of times within a predetermined period at the initial stage of activation, and the largest difference ΔTXO and the smallest difference ΔTXO within the predetermined period are calculated. Difference ΔPT or difference between the largest difference ΔPXO and the smallest difference ΔPXO within a predetermined period ΔPP is determined whether or not it is within a predetermined value, and if it is within a predetermined value, a plurality of differences within the predetermined period. If the error LRN is determined based on ΔTXO or a plurality of differences ΔPXO within the predetermined period, the calculation of the erroneous error LRN in the unstable operating condition at the initial stage of startup is eliminated, and the error LRN is calculated under the stable condition. It becomes possible to realize the determination of the error LRN of.

However, as in the invention of claim 5, if the difference ΔPT or the difference ΔPP does not fall within the predetermined value within the predetermined timeout period, the refrigerant of the outdoor heat exchanger at the time of no frost due to the error LRN. If the evaporation temperature TXObase is not corrected or the refrigerant evaporation pressure PXObase of the outdoor heat exchanger is not corrected due to the error LRN when there is no frost, the error LRN cannot be determined for an unnecessarily long period of time and the outdoor heat cannot be determined. It is possible to avoid the inconvenience that the frost formation determination of the exchanger is not performed.

It is a block diagram of the air conditioner for a vehicle of one Embodiment to which this invention was applied (Example 1). It is a block diagram of the control device of the air conditioner for a vehicle of FIG. It is a schematic diagram of the air flow passage of the air conditioner for a vehicle of FIG. It is a control block diagram concerning the compressor control in the heating mode of the heat pump controller of FIG. It is a control block diagram concerning the compressor control in the dehumidifying heating mode of the heat pump controller of FIG. It is a control block diagram concerning the control of the auxiliary heater (auxiliary heating device) in the dehumidifying heating mode of the heat pump controller of FIG. It is a timing chart for explaining the frost formation determination of the outdoor heat exchanger by the heat pump controller of FIG. 2 based on TXObase and TXO. It is a timing chart for explaining the frost formation determination of the outdoor heat exchanger by the heat pump controller of FIG. 2 based on PXObase and PXO. It is a timing chart explaining the frost formation determination of the outdoor heat exchanger when there is an error LRN in the estimation of TXObase. It is a flowchart explaining the correction control of TXObase by the error LRN by the heat pump controller of FIG. It is a transition diagram of the frost formation determination of the outdoor heat exchanger by the heat pump controller of FIG. It is a timing chart explaining the frost formation determination of the outdoor heat exchanger by the heat pump controller of FIG. 2 based on TXObase and TXO when the error LRN is corrected. It is a block diagram of the air conditioner for vehicles of another Example of this invention (Example 2).

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a configuration diagram of an air conditioner 1 for a vehicle according to an embodiment of the present invention. The vehicle of the embodiment to which the present invention is applied is an electric vehicle (EV) in which an engine (internal combustion engine) is not mounted, and travels by driving an electric motor for traveling with electric power charged in a battery. Yes (neither is shown), and the vehicle air conditioner 1 of the present invention is also driven by the power of the battery. That is, the vehicle air conditioner 1 of the embodiment performs the heating mode by the heat pump operation using the refrigerant circuit in the electric vehicle that cannot be heated by the waste heat of the engine, and further, the dehumidifying heating mode, the dehumidifying cooling mode, the cooling mode, Each operation mode of the MAX cooling mode (maximum cooling mode) and the auxiliary heater independent mode is selectively executed.

It should be noted that the present invention is effective not only for electric vehicles as vehicles but also for so-called hybrid vehicles that use an engine and an electric motor for traveling, and further, it can be applied to ordinary vehicles traveling with an engine. Needless to say.

The vehicle air conditioner 1 of the embodiment air-conditions (heating, cooling, dehumidifying, and ventilating) the interior of the electric vehicle, and includes an electric compressor 2 that compresses the refrigerant and the interior air of the vehicle. Is provided in the air flow passage 3 of the HVAC unit 10 through which air is circulated, and the high-temperature and high-pressure refrigerant discharged from the compressor 2 flows in through the refrigerant pipe 13G, dissipates this refrigerant, and supplies it to the vehicle interior. A radiator 4 as a heater for heating air, an outdoor expansion valve 6 (decompression device) including an electric valve that decompresses and expands the refrigerant during heating, and an outdoor expansion valve 6 (decompression device) provided outside the vehicle interior that functions as a radiator during cooling and heating. An outdoor heat exchanger 7 that exchanges heat between the refrigerant and the outside air to sometimes function as an evaporator, an indoor expansion valve 8 (pressure reducing device) composed of an electric valve that decompresses and expands the refrigerant, and an air flow passage 3 A heat absorber 9 for absorbing heat of the refrigerant during cooling and dehumidification to cool the air supplied to the vehicle interior by sucking it from the inside and outside of the vehicle, and an accumulator 12 and the like are sequentially connected by a refrigerant pipe 13, and a refrigerant circuit is provided. R is configured.

The refrigerant circuit R is filled with a predetermined amount of refrigerant and lubricating oil. The outdoor heat exchanger 7 is provided with an outdoor blower 15. The outdoor blower 15 forcibly ventilates the outdoor air to the outdoor heat exchanger 7 to exchange heat between the outside air and the refrigerant, whereby the outdoor air is outdoors even when the vehicle is stopped (that is, the vehicle speed is 0 km / h). The heat exchanger 7 is configured to ventilate outside air.

Further, the outdoor heat exchanger 7 has a receiver dryer portion 14 and a supercooling portion 16 in sequence on the downstream side of the refrigerant, and the refrigerant pipe 13A discharged from the outdoor heat exchanger 7 receives the receiver via an electromagnetic valve 17 that is opened during cooling. The refrigerant pipe 13B on the outlet side of the supercooling unit 16 is connected to the dryer unit 14 and is connected to the inlet side of the heat exchanger 9 via the indoor expansion valve 8. The receiver dryer section 14 and the supercooling section 16 structurally form a part of the outdoor heat exchanger 7.

Further, the refrigerant pipe 13B between the supercooling unit 16 and the indoor expansion valve 8 is provided in a heat exchange relationship with the refrigerant pipe 13C on the outlet side of the heat absorber 9, and both constitute the internal heat exchanger 19. As a result, the refrigerant flowing into the indoor expansion valve 8 via the refrigerant pipe 13B is configured to be cooled (supercooled) by the low-temperature refrigerant leaving the heat absorber 9.

Further, the refrigerant pipe 13A coming out of the outdoor heat exchanger 7 is branched into the refrigerant pipe 13D, and the branched refrigerant pipe 13D is on the downstream side of the internal heat exchanger 19 via an electromagnetic valve 21 opened during heating. Is connected to the refrigerant pipe 13C in the above. The refrigerant pipe 13C is connected to the accumulator 12, and the accumulator 12 is connected to the refrigerant suction side of the compressor 2. Further, the refrigerant pipe 13E on the outlet side of the radiator 4 is connected to the inlet side of the outdoor heat exchanger 7 via the outdoor expansion valve 6.

Further, the refrigerant pipe 13G between the discharge side of the compressor 2 and the inlet side of the radiator 4 is provided with a solenoid valve 30 (which constitutes a flow path switching device) which is closed during dehumidifying heating and MAX cooling, which will be described later. There is. In this case, the refrigerant pipe 13G branches to the bypass pipe 35 on the upstream side of the solenoid valve 30, and the bypass pipe 35 also constitutes the solenoid valve 40 (which also constitutes the flow path switching device) that is opened during dehumidifying heating and MAX cooling. ) Is communicated with the refrigerant pipe 13E on the downstream side of the outdoor expansion valve 6. The bypass device 45 is composed of the bypass pipe 35, the solenoid valve 30, and the solenoid valve 40.

By configuring the bypass device 45 with such a bypass pipe 35, an electromagnetic valve 30, and an electromagnetic valve 40, a dehumidifying heating mode or MAX in which the refrigerant discharged from the compressor 2 directly flows into the outdoor heat exchanger 7 as described later. It becomes possible to smoothly switch between the cooling mode and the heating mode, the dehumidifying cooling mode, and the cooling mode in which the refrigerant discharged from the compressor 2 flows into the radiator 4.

Further, in the air flow passage 3 on the air upstream side of the heat absorber 9, each suction port of the outside air suction port and the inside air suction port is formed (represented by the suction port 25 in FIG. 1), and this suction port is formed. The suction switching damper 26 for switching the air introduced into the air flow passage 3 into the inside air (inside air circulation mode), which is the air inside the vehicle interior, and the outside air (outside air introduction mode), which is the air outside the vehicle interior, is provided. There is. Further, an indoor blower fan 27 for supplying the introduced inside air and outside air to the air flow passage 3 is provided on the air downstream side of the suction switching damper 26.

Further, in FIG. 1, 23 is an auxiliary heater as an auxiliary heating device (another heater) provided in the vehicle air conditioner 1 of the embodiment. The auxiliary heater 23 of the embodiment is composed of a PTC heater which is an electric heater, and is inside the air flow passage 3 which is on the windward side (air upstream side) of the radiator 4 with respect to the air flow of the air flow passage 3. It is provided in. Then, when the auxiliary heater 23 is energized to generate heat, the air in the air flow passage 3 flowing into the radiator 4 via the endothermic absorber 9 is heated. That is, the auxiliary heater 23 serves as a so-called heater core, which heats or complements the interior of the vehicle. In this embodiment, the above-mentioned radiator 4 and the auxiliary heater 23 serve as heaters.

Here, the air flow passage 3 on the leeward side (downstream side of the air) of the heat absorber 9 of the HVAC unit 10 is partitioned by the partition wall 10A, and the heat exchange passage 3A for heating and the bypass passage 3B bypassing the heat exchange passage 3A are formed. The above-mentioned radiator 4 and auxiliary heater 23 are arranged in the heating heat exchange passage 3A.

Further, in the air flow passage 3 on the wind side of the auxiliary heater 23, the air (inside air or outside air) in the air flow passage 3 after flowing into the air flow passage 3 and passing through the heat absorber 9 is assisted. An air mix damper 28 for adjusting the ratio of ventilation to the heating heat exchange passage 3A in which the heater 23 and the radiator 4 are arranged is provided.

Further, the HVAC unit 10 on the leeward side of the radiator 4 has a FOOT (foot) outlet 29A (first outlet) and a VENT (vent) outlet 29B (a second outlet for the FOOT outlet 29A). Each outlet is formed with respect to the outlet and the DEF outlet 29C (the first outlet) and the DEF (def) outlet 29C (the second outlet). The FOOT outlet 29A is an outlet for blowing air under the feet in the vehicle interior, and is located at the lowest position. The VENT outlet 29B is an outlet for blowing air near the driver's chest and face in the vehicle interior, and is above the FOOT outlet 29A. The DEF outlet 29C is an outlet for blowing air onto the inner surface of the windshield of the vehicle, and is located at the highest position above the other outlets 29A and 29B.

The FOOT outlet 29A, the VENT outlet 29B, and the DEF outlet 29C are provided with a FOOT outlet damper 31A, a VENT outlet damper 31B, and a DEF outlet damper 31C, respectively, which control the amount of air blown out. Has been done.

Next, FIG. 2 shows a block diagram of the control device 11 of the vehicle air conditioner 1 of the embodiment. The control device 11 is composed of an air conditioner controller 20 and a heat pump controller 32, each of which is composed of a microcomputer which is an example of a computer equipped with a processor, and these are CAN (Controller Area Network) and LIN (Local Interconnect Network). It is connected to the vehicle communication bus 65 constituting the above. Further, the compressor 2 and the auxiliary heater 23 are also connected to the vehicle communication bus 65, and the air conditioning controller 20, the heat pump controller 32, the compressor 2 and the auxiliary heater 23 are configured to transmit and receive data via the vehicle communication bus 65. Has been done.

The air conditioning controller 20 is a higher-level controller that controls the air conditioning inside the vehicle interior, and the input of the air conditioning controller 20 includes an outside air temperature sensor 33 that detects the outside air temperature (Tam) of the vehicle and an outside air humidity sensor. The outside air humidity sensor 34, the HVAC suction temperature sensor 36 that detects the temperature of the air that is sucked into the air flow passage 3 from the suction port 25 and flows into the heat absorber 9 (suction air temperature Tas), and the air inside the vehicle (inside air). The inside air temperature sensor 37 that detects the temperature (indoor temperature Tin), the inside air humidity sensor 38 that detects the humidity of the air inside the vehicle, the interior CO ₂ concentration sensor 39 that detects the carbon dioxide concentration inside the vehicle, and the interior of the vehicle. A blowout temperature sensor 41 that detects the temperature of the air blown out to the vehicle, a discharge pressure sensor 42 that detects the discharge refrigerant pressure (discharge pressure Pd) of the compressor 2, and a photo, for example, for detecting the amount of solar radiation into the vehicle interior. The sensor-type solar radiation sensor 51, each output of the vehicle speed sensor 52 for detecting the moving speed (vehicle speed) of the vehicle, and the air conditioning (air conditioner) operation unit 53 for setting the set temperature and switching of the operation mode are connected. ing.

Further, an outdoor blower 15, an indoor blower (blower fan) 27, a suction switching damper 26, an air mix damper 28, and outlet dampers 31A to 31C are connected to the output of the air conditioning controller 20, and they are air-conditioned. It is controlled by the controller 20.

The heat pump controller 32 is a controller that mainly controls the refrigerant circuit R, and the input of the heat pump controller 32 includes a discharge temperature sensor 43 that detects the discharge refrigerant temperature of the compressor 2 and a suction refrigerant pressure of the compressor 2. The suction pressure sensor 44 for detecting the above, the suction temperature sensor 55 for detecting the suction refrigerant temperature Ts of the compressor 2, the radiator temperature sensor 46 for detecting the refrigerant temperature (radiator temperature TCI) of the radiator 4, and the radiator. The radiator pressure sensor 47 that detects the refrigerant pressure (radiator pressure PCI) of 4 and the heat absorber temperature sensor 48 that detects the refrigerant temperature (heat absorber temperature Te) of the heat absorber 9 and the refrigerant pressure of the heat absorber 9 are detected. The heat absorber pressure sensor 49, the auxiliary heater temperature sensor 50 that detects the temperature of the auxiliary heater 23 (auxiliary heater temperature Tptc), and the refrigerant temperature (outdoor heat exchanger temperature TXO) at the outlet of the outdoor heat exchanger 7 are detected. The outputs of the outdoor heat exchanger temperature sensor 54 and the outdoor heat exchanger pressure sensor 56 that detect the refrigerant pressure (outdoor heat exchanger pressure PXO) at the outlet of the outdoor heat exchanger 7 are connected.

Further, the output of the heat pump controller 32 includes an outdoor expansion valve 6, an indoor expansion valve 8, a solenoid valve 30 (for reheating), a solenoid valve 17 (for cooling), a solenoid valve 21 (for heating), and a solenoid valve 40 (bypass). Each solenoid valve is connected and they are controlled by the heat pump controller 32. The compressor 2 and the auxiliary heater 23 each have a built-in controller, and the controllers of the compressor 2 and the auxiliary heater 23 transmit and receive data to and from the heat pump controller 32 via the vehicle communication bus 65, and the heat pump controller 32 transmits and receives data. Be controlled.

The heat pump controller 32 and the air conditioning controller 20 send and receive data to and from each other via the vehicle communication bus 65, and control each device based on the output of each sensor and the settings input by the air conditioning operation unit 53. In the embodiment in this case, the outside air temperature sensor 33, the discharge pressure sensor 42, the vehicle speed sensor 52, the volume air volume Ga of the air flowing into the air flow passage 3 (calculated by the air conditioning controller 20), and the air volume ratio SW by the air mix damper 28 ( The output of the air conditioning operation unit 53 (calculated by the air conditioning controller 20) is transmitted from the air conditioning controller 20 to the heat pump controller 32 via the vehicle communication bus 65, and is used for control by the heat pump controller 32.

With the above configuration, the operation of the vehicle air conditioner 1 of the embodiment will be described next. In this embodiment, the control device 11 (air conditioning controller 20, heat pump controller 32) sets each operation mode of heating mode, dehumidifying heating mode, dehumidifying cooling mode, cooling mode, MAX cooling mode (maximum cooling mode), and auxiliary heater independent mode. Switch and execute. First, the outline of the flow and control of the refrigerant in each operation mode will be described.

(1) Heating mode When the heating mode is selected by the heat pump controller 32 (auto mode) or by manual operation to the air conditioning operation unit 53 (manual mode), the heat pump controller 32 opens the solenoid valve 21 (for heating). Close the solenoid valve 17 (for cooling). Further, the solenoid valve 30 (for reheating) is opened, and the solenoid valve 40 (for bypass) is closed. Then, the compressor 2 is operated. The air conditioning controller 20 operates the blowers 15 and 27, and the air mix damper 28 basically blows out all the air in the air flow passage 3 that has been blown out from the indoor blower 27 and passed through the heat absorber 9 to heat the heat exchange passage 3A for heating. Although the state is such that the auxiliary heater 23 and the radiator 4 of the above are ventilated, the air volume may be adjusted.

As a result, the high-temperature and high-pressure gas refrigerant discharged from the compressor 2 flows into the radiator 4 from the refrigerant pipe 13G via the solenoid valve 30. Since the air in the air flow passage 3 is ventilated through the radiator 4, the air in the air flow passage 3 is the high-temperature refrigerant in the radiator 4 (when the auxiliary heater 23 operates, the auxiliary heater 23 and the radiator 4 are used. ), On the other hand, the refrigerant in the radiator 4 is deprived of heat by air and cooled to be condensed.

The refrigerant liquefied in the radiator 4 exits the radiator 4 and then reaches the outdoor expansion valve 6 via the refrigerant pipe 13E. The refrigerant that has flowed into the outdoor expansion valve 6 is decompressed there, and then flows into the outdoor heat exchanger 7. The refrigerant that has flowed into the outdoor heat exchanger 7 evaporates and draws heat from the outside air that is ventilated by the outdoor blower 15 or by running. That is, the refrigerant circuit R serves as a heat pump. Then, the low-temperature refrigerant that has exited the outdoor heat exchanger 7 enters the accumulator 12 from the refrigerant pipe 13C via the refrigerant pipe 13A, the electromagnetic valve 21, and the refrigerant pipe 13D, and after gas-liquid separation there, the gas refrigerant is used in the compressor 2. Repeat the circulation sucked into. Since the air heated by the radiator 4 (when the auxiliary heater 23 operates, the auxiliary heater 23 and the radiator 4) is blown out from the outlets 29A to 29C, the interior of the vehicle is heated by this. become.

The heat pump controller 32 calculates the target radiator pressure PCO (target value of the radiator pressure PCI) from the target heater temperature TCO (target value of the radiator temperature TCI) calculated by the air conditioning controller 20 from the target outlet temperature TAO, and this target. The rotation speed NC of the compressor 2 is controlled based on the radiator pressure PCO and the refrigerant pressure of the radiator 4 (radiator pressure PCI. High pressure of the refrigerant circuit R) detected by the radiator pressure sensor 47, and the radiator 4 Control the heating by. Further, the heat pump controller 32 opens the outdoor expansion valve 6 based on the refrigerant temperature (radiator temperature TCI) of the radiator 4 detected by the radiator temperature sensor 46 and the radiator pressure PCI detected by the radiator pressure sensor 47. The degree is controlled, and the degree of supercooling SC of the refrigerant at the outlet of the radiator 4 is controlled.

Further, in this heating mode, when the heating capacity of the radiator 4 is insufficient for the heating capacity required for the air conditioning in the vehicle interior, the heat pump controller 32 compensates for the shortage with the heat generated by the auxiliary heater 23. Controls the energization of the auxiliary heater 23. As a result, comfortable vehicle interior heating is realized, and frost formation of the outdoor heat exchanger 7 is also suppressed. At this time, since the auxiliary heater 23 is arranged on the upstream side of the air of the radiator 4, the air flowing through the air flow passage 3 is ventilated to the auxiliary heater 23 in front of the radiator 4.

Here, if the auxiliary heater 23 is arranged on the downstream side of the air of the radiator 4, when the auxiliary heater 23 is configured by the PTC heater as in the embodiment, the temperature of the air flowing into the auxiliary heater 23 is the radiator. Since the temperature is increased by 4, the resistance value of the PTC heater increases, the current value also decreases, and the amount of heat generated decreases. However, by arranging the auxiliary heater 23 on the upstream side of the air of the radiator 4, the example of the embodiment As described above, the ability of the auxiliary heater 23 composed of the PTC heater can be fully exhibited.

(2) Dehumidifying and heating mode Next, in the dehumidifying and heating mode, the heat pump controller 32 opens the solenoid valve 17 and closes the solenoid valve 21. Further, the solenoid valve 30 is closed, the solenoid valve 40 is opened, and the valve opening degree of the outdoor expansion valve 6 is fully closed. Then, the compressor 2 is operated. The air conditioning controller 20 operates the blowers 15 and 27, and the air mix damper 28 basically blows out all the air in the air flow passage 3 that has been blown out from the indoor blower 27 and passed through the heat absorber 9 to heat the heat exchange passage 3A for heating. The auxiliary heater 23 and the radiator 4 are ventilated, but the air volume is also adjusted.

As a result, the high-temperature and high-pressure gas refrigerant discharged from the compressor 2 to the refrigerant pipe 13G flows into the bypass pipe 35 without going to the radiator 4, passes through the solenoid valve 40, and flows into the refrigerant pipe on the downstream side of the outdoor expansion valve 6. It will reach 13E. At this time, since the outdoor expansion valve 6 is fully closed, the refrigerant flows into the outdoor heat exchanger 7. The refrigerant flowing into the outdoor heat exchanger 7 is air-cooled and condensed by traveling there or by the outside air ventilated by the outdoor blower 15. The refrigerant exiting the outdoor heat exchanger 7 flows sequentially from the refrigerant pipe 13A through the solenoid valve 17 to the receiver dryer section 14 and the supercooling section 16. Here the refrigerant is supercooled.

The refrigerant exiting the supercooling section 16 of the outdoor heat exchanger 7 enters the refrigerant pipe 13B, passes through the internal heat exchanger 19, and reaches the indoor expansion valve 8. After the refrigerant is depressurized by the indoor expansion valve 8, it flows into the heat absorber 9 and evaporates. The air blown out from the indoor blower 27 is cooled by the endothermic action at this time, and the moisture in the air condenses and adheres to the heat absorber 9, so that the air in the air flow passage 3 is cooled and It is dehumidified. The refrigerant evaporated in the heat absorber 9 passes through the internal heat exchanger 19 and reaches the accumulator 12 via the refrigerant pipe 13C, and is repeatedly sucked into the compressor 2 through the accumulator 12.

At this time, since the valve opening degree of the outdoor expansion valve 6 is fully closed, it is possible to suppress or prevent the inconvenience that the refrigerant discharged from the compressor 2 flows back from the outdoor expansion valve 6 into the radiator 4. It becomes. As a result, it becomes possible to suppress or eliminate the decrease in the amount of refrigerant circulation and secure the air conditioning capacity. Further, in this dehumidifying / heating mode, the heat pump controller 32 energizes the auxiliary heater 23 to generate heat. As a result, the air cooled and dehumidified by the heat absorber 9 is further heated in the process of passing through the auxiliary heater 23, and the temperature rises, so that the dehumidifying and heating of the vehicle interior is performed.

The heat pump controller 32 is a compressor based on the temperature of the heat absorber 9 (heat absorber temperature Te) detected by the heat absorber temperature sensor 48 and the target heat absorber temperature TEO which is a target value of the heat absorber temperature Te calculated by the air conditioner controller 20. The auxiliary heater 23 is controlled based on the auxiliary heater temperature Tptc detected by the auxiliary heater temperature sensor 50 and the target heater temperature TCO described above (in this case, the target value of the auxiliary heater temperature Tptc) while controlling the rotation speed NC of 2. By controlling the energization (heating by heat generation), the air temperature that is blown into the vehicle interior from each outlet 29A to 29C by heating by the auxiliary heater 23 while appropriately cooling and dehumidifying the air in the heat absorber 9 Accurately prevent the drop. As a result, it becomes possible to control the temperature to an appropriate heating temperature while dehumidifying the air blown into the vehicle interior, and it becomes possible to realize comfortable and efficient dehumidification heating in the vehicle interior.

Since the auxiliary heater 23 is arranged on the upstream side of the air of the radiator 4, the air heated by the auxiliary heater 23 passes through the radiator 4, but in this dehumidifying and heating mode, the refrigerant is sent to the radiator 4. Since the heat is not washed away, the inconvenience that the radiator 4 absorbs heat from the air heated by the auxiliary heater 23 is also eliminated. That is, it is suppressed that the temperature of the air blown into the vehicle interior is lowered by the radiator 4, and the COP is also improved.

(3) Dehumidifying / cooling mode Next, in the dehumidifying / cooling mode, the heat pump controller 32 opens the solenoid valve 17 and closes the solenoid valve 21. Further, the solenoid valve 30 is opened and the solenoid valve 40 is closed. Then, the compressor 2 is operated. The air conditioning controller 20 operates the blowers 15 and 27, and the air mix damper 28 basically blows out all the air in the air flow passage 3 that has been blown out from the indoor blower 27 and passed through the heat absorber 9 to heat the heat exchange passage 3A for heating. The auxiliary heater 23 and the radiator 4 are ventilated, but the air volume is also adjusted.

As a result, the high-temperature and high-pressure gas refrigerant discharged from the compressor 2 flows into the radiator 4 from the refrigerant pipe 13G via the solenoid valve 30. Since the air in the air flow passage 3 is ventilated through the radiator 4, the air in the air flow passage 3 is heated by the high temperature refrigerant in the radiator 4, while the refrigerant in the radiator 4 heats the air. It is deprived, cooled, and condensed.

The refrigerant leaving the radiator 4 reaches the outdoor expansion valve 6 via the refrigerant pipe 13E, and flows into the outdoor heat exchanger 7 via the outdoor expansion valve 6 which is slightly opened and controlled. The refrigerant flowing into the outdoor heat exchanger 7 is air-cooled and condensed by traveling there or by the outside air ventilated by the outdoor blower 15. The refrigerant exiting the outdoor heat exchanger 7 flows sequentially from the refrigerant pipe 13A through the solenoid valve 17 to the receiver dryer section 14 and the supercooling section 16. Here the refrigerant is supercooled.

The refrigerant exiting the supercooling section 16 of the outdoor heat exchanger 7 enters the refrigerant pipe 13B, passes through the internal heat exchanger 19, and reaches the indoor expansion valve 8. After the refrigerant is depressurized by the indoor expansion valve 8, it flows into the heat absorber 9 and evaporates. Due to the endothermic action at this time, the moisture in the air blown out from the indoor blower 27 condenses and adheres to the heat absorber 9, so that the air is cooled and dehumidified.

The refrigerant evaporated in the heat absorber 9 passes through the internal heat exchanger 19 and reaches the accumulator 12 via the refrigerant pipe 13C, and is repeatedly sucked into the compressor 2 through the accumulator 12. In this dehumidifying / cooling mode, since the heat pump controller 32 does not energize the auxiliary heater 23, it is cooled by the heat absorber 9, and the dehumidified air is reheated in the process of passing through the radiator 4 (the heat dissipation capacity is lower than that during heating). Will be done. As a result, the interior of the vehicle is dehumidified and cooled.

The heat pump controller 32 of the compressor 2 is based on the temperature of the heat absorber 9 (heat absorber temperature Te) detected by the heat absorber temperature sensor 48 and the target heat absorber temperature TEO (transmitted from the air conditioning controller 20) which is the target value thereof. Controls the number of revolutions NC. Further, the heat pump controller 32 calculates the target radiator pressure PCO from the above-mentioned target heater temperature TCO, and the target radiator pressure PCO and the refrigerant pressure (radiator pressure PCI) of the radiator 4 detected by the radiator pressure sensor 47. The valve opening degree of the outdoor expansion valve 6 is controlled based on the high pressure of the refrigerant circuit R), and the heating by the radiator 4 is controlled.

(4) Cooling Mode Next, in the cooling mode, the heat pump controller 32 fully opens the valve opening degree of the outdoor expansion valve 6 in the state of the dehumidifying cooling mode. Then, the compressor 2 is operated and the auxiliary heater 23 is not energized. The air conditioning controller 20 operates the blowers 15 and 27, and in the air mix damper 28, the air in the air flow passage 3 blown out from the indoor blower 27 and passed through the heat absorber 9 is the auxiliary heater 23 of the heat exchange passage 3A for heating. And the ratio of ventilation to the radiator 4 is adjusted.

As a result, the high-temperature and high-pressure gas refrigerant discharged from the compressor 2 flows into the radiator 4 from the refrigerant pipe 13G via the solenoid valve 30, and the refrigerant discharged from the radiator 4 passes through the refrigerant pipe 13E and the outdoor expansion valve 6 To reach. At this time, since the outdoor expansion valve 6 is fully opened, the refrigerant passes through it and flows into the outdoor heat exchanger 7 as it is, where it is air-cooled by running or by the outside air ventilated by the outdoor blower 15 and condensed. Liquefaction. The refrigerant exiting the outdoor heat exchanger 7 flows sequentially from the refrigerant pipe 13A through the solenoid valve 17 to the receiver dryer section 14 and the supercooling section 16. Here the refrigerant is supercooled.

The refrigerant exiting the supercooling section 16 of the outdoor heat exchanger 7 enters the refrigerant pipe 13B, passes through the internal heat exchanger 19, and reaches the indoor expansion valve 8. After the refrigerant is depressurized by the indoor expansion valve 8, it flows into the heat absorber 9 and evaporates. The air blown out from the indoor blower 27 is cooled by the endothermic action at this time. Further, the moisture in the air condenses and adheres to the heat absorber 9.

The refrigerant evaporated in the heat absorber 9 passes through the internal heat exchanger 19 and reaches the accumulator 12 via the refrigerant pipe 13C, and is repeatedly sucked into the compressor 2 through the accumulator 12. The dehumidified air cooled by the heat absorber 9 is blown out into the vehicle interior from the outlets 29A to 29C (a part of the air passes through the radiator 4 to exchange heat), which cools the vehicle interior. It will be done. Further, in this cooling mode, the heat pump controller 32 uses the compressor 2 based on the temperature (heat absorber temperature Te) of the heat absorber 9 detected by the heat absorber temperature sensor 48 and the above-mentioned target heater temperature TEO which is the target value thereof. Controls the number of rotations NC.

(5) MAX cooling mode (maximum cooling mode)
Next, in the MAX cooling mode as the maximum cooling mode, the heat pump controller 32 opens the solenoid valve 17 and closes the solenoid valve 21. Further, the solenoid valve 30 is closed, the solenoid valve 40 is opened, and the valve opening degree of the outdoor expansion valve 6 is fully closed. Then, the compressor 2 is operated and the auxiliary heater 23 is not energized. The air conditioning controller 20 operates the blowers 15 and 27, and in the air mix damper 28, the air in the air flow passage 3 blown out from the indoor blower 27 and passed through the heat absorber 9 is an auxiliary heater of the heat exchange passage 3A for heating. The ratio of ventilation to 23 and the radiator 4 is adjusted.

As a result, the high-temperature and high-pressure gas refrigerant discharged from the compressor 2 to the refrigerant pipe 13G flows into the bypass pipe 35 without going to the radiator 4, passes through the solenoid valve 40, and flows into the refrigerant pipe on the downstream side of the outdoor expansion valve 6. It will reach 13E. At this time, since the outdoor expansion valve 6 is fully closed, the refrigerant flows into the outdoor heat exchanger 7. The refrigerant flowing into the outdoor heat exchanger 7 is air-cooled and condensed by traveling there or by the outside air ventilated by the outdoor blower 15. The refrigerant exiting the outdoor heat exchanger 7 flows sequentially from the refrigerant pipe 13A through the solenoid valve 17 to the receiver dryer section 14 and the supercooling section 16. Here the refrigerant is supercooled.

The refrigerant exiting the supercooling section 16 of the outdoor heat exchanger 7 enters the refrigerant pipe 13B, passes through the internal heat exchanger 19, and reaches the indoor expansion valve 8. After the refrigerant is depressurized by the indoor expansion valve 8, it flows into the heat absorber 9 and evaporates. The air blown out from the indoor blower 27 is cooled by the endothermic action at this time. Further, since the moisture in the air condenses and adheres to the heat absorber 9, the air in the air flow passage 3 is dehumidified. The refrigerant evaporated in the heat absorber 9 passes through the internal heat exchanger 19 and reaches the accumulator 12 via the refrigerant pipe 13C, and is repeatedly sucked into the compressor 2 through the accumulator 12. At this time, since the outdoor expansion valve 6 is fully closed, it is possible to suppress or prevent the inconvenience that the refrigerant discharged from the compressor 2 flows back from the outdoor expansion valve 6 into the radiator 4. .. As a result, it becomes possible to suppress or eliminate the decrease in the amount of refrigerant circulation and secure the air conditioning capacity.

Here, since the high-temperature refrigerant is flowing through the radiator 4 in the cooling mode described above, direct heat conduction from the radiator 4 to the HVAC unit 10 is not a little generated, but in this MAX cooling mode, the refrigerant is flowing through the radiator 4. Does not flow, so that the heat transferred from the radiator 4 to the HVAC unit 10 does not heat the air in the air flow passage 3 from the heat absorber 9. Therefore, the vehicle interior is strongly cooled, and particularly in an environment where the outside air temperature Tam is high, the vehicle interior can be quickly cooled and comfortable vehicle interior air conditioning can be realized. Further, even in this MAX cooling mode, the heat pump controller 32 is a compressor based on the temperature of the heat absorber 9 (heat absorber temperature Te) detected by the heat absorber temperature sensor 48 and the above-mentioned target heat absorber temperature TEO which is the target value thereof. The number of rotations NC of 2 is controlled.

(6) Auxiliary heater independent mode The control device 11 of the embodiment stops the compressor 2 and the outdoor blower 15 of the refrigerant circuit R when over-frost occurs in the outdoor heat exchanger 7, and the auxiliary heater 23 Has an auxiliary heater independent mode in which the vehicle interior is heated only by the auxiliary heater 23. Also in this case, the heat pump controller 32 controls the energization (heat generation) of the auxiliary heater 23 based on the auxiliary heater temperature Tptc detected by the auxiliary heater temperature sensor 50 and the target heater temperature TCO described above.

Further, the air conditioning controller 20 operates the indoor blower 27, and the air mix damper 28 ventilates the air in the air flow passage 3 blown out from the indoor blower 27 to the auxiliary heater 23 of the heating heat exchange passage 3A to increase the air volume. It is in a state to be adjusted. Since the air heated by the auxiliary heater 23 is blown out into the vehicle interior from the outlets 29A to 29C, the interior of the vehicle is heated by this.

(7) Switching of operation mode The air conditioning controller 20 calculates the target blowout temperature TAO described above from the following formula (I). This target blowing temperature TAO is a target value of the temperature of the air blown into the vehicle interior.
TAO = (Tset-Tin) x K + Tbal (f (Tset, SUN, Tam))
・ ・ (I)
Here, Tset is the set temperature in the vehicle interior set by the air conditioning operation unit 53, Tin is the indoor temperature detected by the inside air temperature sensor 37, K is a coefficient, Tbal is the set temperature Tset, and the amount of solar radiation detected by the solar radiation sensor 51. It is a balance value calculated from the outside air temperature Tam detected by the SUN and the outside air temperature sensor 33. In general, the target outlet temperature TAO increases as the outside air temperature Tam decreases, and decreases as the outside air temperature Tam increases.

The heat pump controller 32 is any of the above operation modes based on the outside air temperature Tam (detected by the outside air temperature sensor 33) transmitted from the air conditioning controller 20 via the vehicle communication bus 65 at the time of activation and the target blowout temperature TAO. The operation mode is selected, and each operation mode is transmitted to the air conditioning controller 20 via the vehicle communication bus 65. After startup, the outside air temperature Tam, the humidity inside the vehicle, the target blowout temperature TAO, the heating temperature TH (the temperature of the air on the leeward side of the radiator 4; estimated value), the target heater temperature TCO, the heat absorber temperature Te, By switching each operation mode based on parameters such as the target heat absorber temperature TEO and the presence or absence of dehumidification request in the vehicle interior, the heating mode, dehumidification heating mode, and dehumidification can be performed accurately according to the environmental conditions and the necessity of dehumidification. By switching between the cooling mode, the cooling mode, the MAX cooling mode, and the auxiliary heater independent mode, the temperature of the air blown into the vehicle interior is controlled to the target outlet temperature TAO, and comfortable and efficient vehicle interior air conditioning is realized.

(8) Control of the Compressor 2 in the Heating Mode by the Heat Pump Controller 32 Next, the control of the compressor 2 in the heating mode described above will be described in detail with reference to FIG. FIG. 4 is a control block diagram of the heat pump controller 32 that determines the target rotation speed (compressor target rotation speed) TGNCh of the compressor 2 for the heating mode. The F / F (feed forward) operation amount calculation unit 58 of the heat pump controller 32 has the outside air temperature Tam obtained from the outside air temperature sensor 33, the blower voltage BLV of the indoor blower 27, and SW = (TAO-Te) / (TH-Te). ), The air volume ratio SW by the air mix damper 28, the target supercooling degree TGSC which is the target value of the supercooling degree SC at the outlet of the radiator 4, and the above-mentioned target heater which is the target value of the temperature of the radiator 4 The F / F operation amount TGNChff of the compressor target rotation speed is calculated based on the temperature TCO (transmitted from the air conditioning controller 20) and the target radiator pressure PCO which is the target value of the pressure of the radiator 4.

Here, the TH for calculating the air volume ratio SW is the temperature of the air on the leeward side of the radiator 4 (hereinafter referred to as the heating temperature), and the heat pump controller 32 uses the equation (II) for the primary delay calculation shown below. presume.
TH = (INTL x TH0 + Tau x THz) / (Tau + INTL) ... (II)
Here, INTL is the calculation cycle (constant), Tau is the time constant of the first-order delay, TH0 is the steady-state value of the heating temperature TH in the steady state before the first-order delay calculation, and THH is the previous value of the heating temperature TH. By estimating the heating temperature TH in this way, it is not necessary to provide a special temperature sensor.

By changing the time constant Tau and the steady-state value TH0 according to the operation mode described above, the heat pump controller 32 makes the estimation formula (II) described above different depending on the operation mode, and estimates the heating temperature TH. Then, this heating temperature TH is transmitted to the air conditioning controller 20 via the vehicle communication bus 65.

The target radiator pressure PCO is calculated by the target value calculation unit 59 based on the target supercooling degree TGSC and the target heater temperature TCO. Further, the F / B (feedback) operation amount calculation unit 60 calculates the F / B operation amount TGNChfb of the compressor target rotation speed based on the target radiator pressure PCO and the radiator pressure PCI which is the refrigerant pressure of the radiator 4. To do. Then, the F / F operation amount TGNCnff calculated by the F / F operation amount calculation unit 58 and the TGNChfb calculated by the F / B operation amount calculation unit 60 are added by the adder 61, and are controlled by the limit setting unit 62 as the control upper limit value. After the lower limit is set, it is determined as the compressor target rotation speed TGNCh. In the heating mode, the heat pump controller 32 controls the rotation speed NC of the compressor 2 based on the compressor target rotation speed TGNCh.

(9) Control of the Compressor 2 and the Auxiliary Heater 23 in the Dehumidifying and Heating Mode by the Heat Pump Controller 32 On the other hand, FIG. 5 determines the target rotation speed (compressor target rotation speed) TGNCc of the compressor 2 for the dehumidifying and heating mode. It is a control block diagram of a heat pump controller 32. The F / F operation amount calculation unit 63 of the heat pump controller 32 has an outside air temperature Tam, a volume air volume Ga of the air flowing into the air flow passage 3, and a target heat dissipation which is a target value of the pressure of the radiator 4 (radiator pressure PCI). The F / F operation amount TGNCcff of the compressor target rotation speed is calculated based on the device pressure PCO and the target heat absorber temperature TEO which is the target value of the temperature of the heat absorber 9 (heat absorber temperature Te).

Further, the F / B operation amount calculation unit 64 calculates the F / B operation amount TGNCcfb of the compressor target rotation speed based on the target endothermic temperature TEO (transmitted from the air conditioning controller 20) and the endothermic temperature Te. Then, the F / F operation amount TGNCcff calculated by the F / F operation amount calculation unit 63 and the F / B operation amount TGNCcffb calculated by the F / B operation amount calculation unit 64 are added by the adder 66, and are added by the limit setting unit 67. After the limit of the control upper limit value and the control lower limit value is set, it is determined as the compressor target rotation speed TGNCc. In the dehumidifying / heating mode, the heat pump controller 32 controls the rotation speed NC of the compressor 2 based on the compressor target rotation speed TGNCc.

Further, FIG. 6 is a control block diagram of the heat pump controller 32 that determines the auxiliary heater requesting capacity TGQPTC of the auxiliary heater 23 in the dehumidifying heating mode. The target heater temperature TCO and the auxiliary heater temperature Tptc are input to the subtractor 73 of the heat pump controller 32, and the deviation (TCO-Tptc) between the target heater temperature TCO and the auxiliary heater temperature Tptc is calculated. This deviation (TCO-Tptc) is input to the F / B control unit 74, and the F / B control unit 74 eliminates the deviation (TCO-Tptc) so that the auxiliary heater temperature Tptc becomes the target heater temperature TCO. Calculates the required capacity F / B operation amount.

The auxiliary heater requesting capacity F / B operation amount calculated by the F / B control unit 74 is determined as the auxiliary heater requesting capacity TGQPTC after the limit setting unit 76 limits the control upper limit value and the control lower limit value. .. In the dehumidifying heating mode, the controller 32 controls the energization of the auxiliary heater 23 based on the auxiliary heater required capacity TGQPTC, so that the auxiliary heater temperature Tptc becomes the target heater temperature TCO and the auxiliary heater 23 generates heat (heating). To control.

In this way, the heat pump controller 32 controls the operation of the compressor based on the heat absorber temperature Te and the target heat absorber temperature TEO in the dehumidifying heating mode, and also controls the heat generation of the auxiliary heater 23 based on the target heater temperature TCO. As a result, the cooling and dehumidification by the heat absorber 9 and the heating by the auxiliary heater 23 in the dehumidification and heating mode are accurately controlled. As a result, it is possible to control the temperature to a more accurate heating temperature while dehumidifying the air blown into the vehicle interior more appropriately, and to realize more comfortable and efficient dehumidification and heating of the vehicle interior. Will be able to.

(10) Control of Air Mix Damper 28 Next, control of the air mix damper 28 by the air conditioning controller 20 will be described with reference to FIG. In FIG. 3, Ga is the volumetric air volume of the air flowing into the air flow passage 3 described above, Te is the temperature of the endothermic absorber, and TH is the heating temperature described above (the temperature of the air on the leeward side of the radiator 4).

The air conditioning controller 20 has an air volume of the ratio based on the air volume ratio SW that ventilates the radiator 4 and the auxiliary heater 23 of the heat exchange passage 3A for heating calculated by the above formula (the following formula (III)). By controlling the air mix damper 28, the amount of ventilation to the radiator 4 (and the auxiliary heater 23) is adjusted.
SW = (TAO-Te) / (TH-Te) ... (III)

That is, the air volume ratio SW that ventilates the radiator 4 and the auxiliary heater 23 of the heat exchange passage 3A for heating changes in the range of 0 ≦ SW ≦ 1, and “0” does not allow ventilation to the heat exchange passage 3A for heating. , The air mix fully closed state in which all the air in the air flow passage 3 is ventilated to the bypass passage 3B, and the air mix fully open state in which all the air in the air flow passage 3 is ventilated to the heating heat exchange passage 3A in "1". It becomes. That is, the air volume to the radiator 4 is Ga × SW.

(11) Frost determination control of the outdoor heat exchanger As described above, in the heating mode, the outdoor heat exchanger 7 absorbs heat from the outside air and becomes low in temperature, so that the moisture in the outside air becomes frost in the outdoor heat exchanger 7. Adheres. When this frost formation grows, the heat exchange between the outdoor heat exchanger 7 and the ventilated outside air is significantly hindered, and the air conditioning performance deteriorates. In addition, the outdoor blower 15 and the like may be damaged due to over-frosting. Therefore, the heat pump controller 32 stops the compressor 2 as described later, or flows the high-temperature refrigerant from the compressor 2 through the outdoor heat exchanger 7 to defrost the outdoor heat exchanger 7. Before that, it is determined whether or not the outdoor heat exchanger 7 is frosted.

(11-1) Judgment of frost formation on the outdoor heat exchanger (Part 1)
Next, an example of frost formation determination of the outdoor heat exchanger 7 will be described with reference to FIG. 7. First, the heat pump controller 32 determines the frost formation of the outdoor heat exchanger 7 when (i) of the following frost formation determination permission conditions is satisfied and any one of (ii) to (iv) is satisfied. Allow.

[Frost judgment permission conditions]
(I) The operation mode is the heating mode.
(Ii) The high pressure has converged to the target value. Specifically, for example, the state in which the absolute value of the difference (PCO-PCI) between the target radiator pressure PCO and the radiator pressure PCI is equal to or less than the predetermined value A continues for a predetermined time t1 (sec). Be done.
(Iii) A predetermined time t2 (sec) has elapsed after the transition to the heating mode.
(Iv) The vehicle speed fluctuation is less than or equal to the predetermined value (the acceleration / deceleration of the vehicle is less than or equal to the predetermined value). The acceleration / deceleration of the vehicle is, for example, the difference (VSP-VSPz) between the current vehicle speed VSP and the vehicle speed VSPz one second before the current vehicle speed VSP.
The conditions (ii) and (iii) are conditions for eliminating erroneous determination that occurs in the transitional period of the operating state. In addition, the above condition (iv) is added because an erroneous determination occurs even when the vehicle speed fluctuation is large.

When the above frosting determination permission condition is satisfied and the frosting determination is permitted, the heat pump controller 32 has the current refrigerant evaporation temperature TXO of the outdoor heat exchanger 7 obtained from the outdoor heat exchanger temperature sensor 54 and the outside air. Based on the refrigerant evaporation temperature TXObase of the outdoor heat exchanger 7 when there is no frost on the outdoor heat exchanger 7 in a low humidity environment, it is determined whether or not the outdoor heat exchanger 7 is frosted. Do. In this case, the heat pump controller 32 estimates the refrigerant evaporation temperature TXObase of the outdoor heat exchanger 7 at the time of no frost by calculating using the following equation (IV).

TXObase = f (Tam, NC, Ga * SW, VSP, PCI)
= K1 x Tam + k2 x NC + k3 x Ga * SW + k4 x VSS + k5 x PCI
・ ・ (IV)

Here, Tam, which is a parameter of the equation (IV), is the outside air temperature obtained from the outside air temperature sensor 33, NC is the rotation speed of the compressor 2, Ga * SW is the air volume to the radiator 4, and VSP is obtained from the vehicle speed sensor 52. The vehicle speed and PCI to be obtained are radiator pressures, and k1 to k5 are coefficients, which are obtained by experiments in advance.

The outside air temperature Tam is an index indicating the suction air temperature (environmental condition) of the outdoor heat exchanger 7, and the lower the outside air temperature Tam (the suction air temperature of the outdoor heat exchanger 7), the lower the TXObase tends to be. Therefore, the coefficient k1 is a positive value. Similarly, the index indicating the suction air temperature of the outdoor heat exchanger 7 is not limited to the outside air temperature Tam.
Further, the rotation speed NC of the compressor 2 is an index indicating the refrigerant flow rate (operating condition) in the refrigerant circuit R, and the higher the rotation speed NC (the larger the refrigerant flow rate), the lower the TXObase tends to be. Therefore, the coefficient k2 has a negative value.
Further, Ga * SW is an index indicating the passing air volume (operating condition) of the radiator 4, and the larger the Ga * SW (the larger the passing air volume of the radiator 4), the lower the TXObase tends to be. Therefore, the coefficient k3 has a negative value. The index indicating the amount of air passing through the radiator 4 is not limited to this, and the blower voltage BLV of the indoor blower 27 may be used.
Further, the vehicle speed VSP is an index indicating the passing wind speed (operating condition) of the outdoor heat exchanger 7, and the lower the vehicle speed VSP (the lower the passing wind speed of the outdoor heat exchanger 7), the lower the TXObase tends to be. Therefore, the coefficient k4 is a positive value. The index indicating the passing wind speed of the outdoor heat exchanger 7 is not limited to this, and the voltage of the outdoor blower 15 may be used.
Further, the radiator pressure PCI is an index indicating the refrigerant pressure (operating condition) of the radiator 4, and the higher the radiator pressure PCI, the lower the TXObase tends to be. Therefore, the coefficient k5 has a negative value.
The parameters of the formula (IV) of this embodiment are the outside air temperature Tam, the rotation speed NC of the compressor 2, the passing air volume Ga * SW of the radiator 4, the vehicle speed VSS, and the radiator pressure PCI. The parameter of IV) is not limited to all of the above, and any one of them or a combination thereof may be used.

Next, the controller 32 uses the difference ΔTXO (ΔTXO = TXObase-TXO) between the refrigerant evaporation temperature TXObase at the time of no frost and the current refrigerant evaporation temperature TXO obtained by substituting the values of the current parameters into the equation (IV). ) Is calculated, and the state in which the refrigerant evaporation temperature TXO is lower than the refrigerant evaporation temperature TXObase at the time of no frost and the difference ΔTXO is equal to or more than the predetermined value dTXOFST (deg) continues for a predetermined time t3 (sec) or more. , It is determined that the outdoor heat exchanger 7 is frosted.

In FIG. 7, the solid line shows the change in the refrigerant evaporation temperature TXO of the outdoor heat exchanger 7, and the broken line shows the change in the refrigerant evaporation temperature TXObase when there is no frost. If there is no problem in estimating the refrigerant evaporation temperature TXObase during non-frosting, the refrigerant evaporation temperature TXO of the outdoor heat exchanger 7 and the refrigerant evaporation temperature TXObase during non-frosting are approximately the same values at the initial stage of startup (non-frosting). It becomes. As the heating mode progresses, the temperature inside the vehicle becomes warmer, and the load on the vehicle air conditioner 1 decreases. Therefore, the above-mentioned refrigerant flow rate and the amount of air passing through the radiator 4 also decrease, and the formula (IV) is used. The calculated TXObase (broken line in FIG. 7) increases.

On the other hand, when frost is formed on the outdoor heat exchanger 7, the heat exchange performance with the outside air is hindered, so that the refrigerant evaporation temperature TXO (solid line) decreases and eventually falls below TXObase. Then, when the refrigerant evaporation temperature TXO further decreases, the difference ΔTXO (TXObase-TXO) becomes a predetermined value dTXOFST or more, and the state continues for a predetermined time t3 or more, the heat pump controller 32 determines that frost has formed and lands. Set the frost detection flag.

(11-2) Operation when it is determined that the outdoor heat exchanger is frosted If the heat pump controller 32 determines that the outdoor heat exchanger 7 is frosted as described above, does the compressor 2 stop? , The outdoor heat exchanger 7 is defrosted (while the vehicle is stopped). In the defrosting operation of the outdoor heat exchanger 7, for example, the heat pump controller 32 opens the solenoid valve 40 and the solenoid valve 21, closes the solenoid valve 30 and the solenoid valve 17, and operates the compressor 2. As a result, the high-temperature and high-pressure gas refrigerant (hot gas) discharged from the compressor 2 is in a state of directly flowing into the outdoor heat exchanger 7 via the solenoid valve 40. As a result, the outdoor heat exchanger 7 is heated, so that the frost formation is melted and removed. The refrigerant discharged from the outdoor heat exchanger 7 is sucked into the compressor 2 via the solenoid valve 21. Then, when a predetermined time has elapsed from the start, the heat pump controller 32 ends the defrosting operation and returns to the heating mode.

(11-3) Judgment of frost formation on the outdoor heat exchanger (Part 2)
Next, another example of frost formation determination of the outdoor heat exchanger 7 will be described with reference to FIG. The same applies to the frosting determination permission conditions described in the above-mentioned frosting determination (No. 1). Then, when the frost formation determination permission condition is satisfied and the frost formation determination is permitted, in this embodiment, the heat pump controller 32 is the current refrigerant evaporation of the outdoor heat exchanger 7 obtained from the outdoor heat exchanger pressure sensor 56. Based on the pressure PXO and the refrigerant evaporation pressure PXObase of the outdoor heat exchanger 7 when the outdoor air is not frosted on the outdoor heat exchanger 7 in a low humidity environment, the outdoor heat exchanger 7 is frosted. Whether or not it is determined. In this case, the heat pump controller 32 estimates the refrigerant evaporation pressure PXObase of the outdoor heat exchanger 7 at the time of no frost by calculating using the following equation (V).

PXObase = f (Tam, NC, Ga * SW, VSP, PCI)
= K6 x Tam + k7 x NC + k8 x Ga * SW + k9 x VSS + k10 x PCI
・ ・ (V)

Since each parameter of the equation (V) is the same as that of the equation (IV), the description thereof will be omitted. Further, each coefficient k6 to k10 has the same tendency (positive or negative) as each of the above-mentioned coefficients k1 to k5. Next, in the heat pump controller 32, the difference between the refrigerant evaporation pressure PXObase at the time of no frost and the current refrigerant evaporation pressure PXO obtained by substituting the values of the current parameters into the equation (v) ΔPXO (ΔPXO = PXObase−). PXO) was calculated, and the state in which the refrigerant evaporation pressure PXO was lower than the refrigerant evaporation pressure PXObase at the time of no frost and the difference ΔPXO became a predetermined value dPXOFST (deg) or more continued for a predetermined time t4 (sec) or more. In this case, it is determined that the outdoor heat exchanger 7 is frosted.

In FIG. 8, the solid line shows the change in the refrigerant evaporation pressure PXO of the outdoor heat exchanger 7, and the broken line shows the change in the refrigerant evaporation pressure PXObase when there is no frost. If there is no problem in estimating the refrigerant evaporation pressure PXObase during non-frosting, the refrigerant evaporation pressure PXO of the outdoor heat exchanger 7 and the refrigerant evaporation pressure PXObase during non-frosting are approximately the same values at the initial stage of startup (non-frosting). It becomes. As the heating mode progresses, the temperature inside the vehicle becomes warmer, and the load on the vehicle air conditioner 1 decreases. Therefore, the above-mentioned refrigerant flow rate and the amount of air passing through the radiator 4 also decrease, and the formula (V) is used. The calculated PXObase (broken line in FIG. 8) increases.

On the other hand, when frost is formed on the outdoor heat exchanger 7, the heat exchange performance with the outside air is hindered, so that the refrigerant evaporation pressure PXO (solid line) decreases and eventually falls below the PXObase. Then, when the decrease in the refrigerant evaporation pressure PXO further progresses, the difference ΔPXO (PXObase-PXO) becomes a predetermined value dPXOFST or more, and the state continues for a predetermined time t4 or more, the heat pump controller 32 determines that frost has formed and is outdoors. The control at the time of frost formation described above for the heat exchanger 7 is started.

(11-4) Correction of Refrigerant Evaporation Temperature TXObase of Outdoor Heat Exchanger During Non-frosting Next, the calculation of the refrigerant evaporation temperature TXObase of the outdoor heat exchanger 7 during non-frosting with reference to FIGS. 9 to 12. The offset correction control for correcting the error will be described. The case of the refrigerant evaporation temperature TXObase of the outdoor heat exchanger 7 at the time of no frost will be described below, but the same applies to the refrigerant evaporation pressure PXObase of the outdoor heat exchanger 7 at the time of no frost. However, the LRN in the following explanation is the error of the estimated value of the refrigerant evaporation pressure PXObase of the outdoor heat exchanger 7 at the time of no frost at the initial stage of startup, and the difference ΔPT between the difference ΔTXOmax and ΔTXOmin is the case of the refrigerant evaporation pressure PXObase. It shall be replaced by the difference ΔPP between the difference ΔPXOmax and ΔPXOmin.

As described above, the refrigerant evaporation temperature TXObase of the outdoor heat exchanger 7 at the time of no frost is estimated by the calculation using the equation (IV) based on the outside air temperature Tam and others detected by the outside air temperature sensor 33. For example, if the outside air temperature sensor 33 itself and the parts to which it is attached (all parts) vary and the detected values are different from the original ones, the refrigerant evaporation temperature TXObase of the outdoor heat exchanger 7 at the time of no frost formation. An error LRN occurs in the estimated value of.

For example, the error on the side where this error LRN is lower than the actual refrigerant evaporation temperature TXO of the outdoor heat exchanger 7 and the refrigerant evaporation temperature TXObase of the outdoor heat exchanger 7 when there is no frost (frosting of the outdoor heat exchanger 7). If the error is (an error to the side that does not detect), the refrigerant evaporation temperature TXObase (broken line) of the outdoor heat exchanger 7 during non-frost formation as shown in FIG. 9 from the initial start of the vehicle air conditioner 1 in the heating mode. ) Is lower than the actual refrigerant evaporation temperature TXO (solid line) by the error LRN, and as described above, frost is formed on the outdoor heat exchanger 7 and the refrigerant evaporation temperature TXO (solid line) is lowered. However, TXO does not fall below TXObase, and their difference ΔTXO (TXObase-TXO) does not exceed the above-mentioned predetermined value dTXOFST, and frost formation in the outdoor heat exchanger 7 cannot be detected.

Therefore, the heat pump controller 32 normally executes offset correction control for correcting the error LRN at the initial stage of startup in which frost has not yet occurred in the outdoor heat exchanger 7. FIG. 10 is a flowchart illustrating the offset correction control of the error LRN by the heat pump controller, and FIG. 11 is a transition diagram of frost formation determination. The heat pump controller 32 waits for a predetermined time from the start (start of operation) in step S1 of FIG. 10, then proceeds to step S2, calculates and estimates the refrigerant evaporation temperature TXObase of the outdoor heat exchanger 7 at the time of no frost, and estimates the outdoor. The actual refrigerant evaporation temperature TXO of the outdoor heat exchanger 7 detected by the heat exchanger temperature sensor 54 is taken in, and the difference ΔTXO (TXObase-TXO) is calculated.

The heat pump controller 32 executes the calculation of this difference ΔTXO a plurality of times (for example, 5 times) within a predetermined period t5 (for example, 1 minute) at a predetermined interval (an interval sufficiently shorter than t5, for example, 6s) and records it as a history in the database DB. To go. Then, from the history recorded in the database DB in step S3, the difference ΔPT (absolute value) between the largest difference ΔTXOmax and the smallest difference ΔTXOmin within the predetermined period t5 is calculated. Then, in step S4, it is determined whether or not this difference ΔPT is within a predetermined value (for example, 0.6 deg), and if it is not within the predetermined value, the process proceeds to step S5, and a predetermined timeout period t6 from the preset startup is performed. It is determined whether or not (a time sufficiently longer than t5, for example, 6 minutes, etc.) has elapsed, and if not, the process returns to step S2 and this is repeated.

When the difference ΔPT is within the predetermined value in step S4 and the operating state becomes stable, the heat pump controller 32 determines the difference ΔTXO based on the plurality of differences ΔTXO that are the calculation sources when the difference ΔPT is within the predetermined value. The average value is determined as the error LRN between the actual refrigerant evaporation temperature TXO of the outdoor heat exchanger 7 and the refrigerant evaporation temperature TXObase (estimated value) of the outdoor heat exchanger 7 at the time of no frost, and the process proceeds to step S7.

In this step S7, it is determined whether or not the error LRN is smaller than 0 (zero). Since the error LRN is originally a value based on ΔTXO (TXObase-TXO), the fact that the error LRN is smaller than 0 means that the outdoor heat exchange at the time of no frost than the actual refrigerant evaporation temperature TXO of the outdoor heat exchanger 7. This is an error on the side where the refrigerant evaporation temperature TXObase of the vessel 7 becomes low (an error on the side where frost formation of the outdoor heat exchanger 7 is not detected).

When the error LRN is smaller than 0 in step S7, it is assumed that the heat pump controller 32 has an error in the estimated value of the refrigerant evaporation temperature TXObase of the outdoor heat exchanger 7 when there is no frost on the side that does not detect frost. The determination is made, and the process proceeds to step S9, where the error LRN = 0-ΔTXO (the above average value) is set, and the estimated value of the refrigerant evaporation temperature TXObase of the outdoor heat exchanger 7 at the time of no frost is corrected. At this time, since the error LRN (= average value of ΔTXO) is originally a negative value, the value of the error LRN becomes a positive value in step S9, and the amount of the error LRN is the amount of the refrigerant of the outdoor heat exchanger 7 when there is no frost. The evaporation temperature TXObase is raised, the error LRN is canceled or reduced to be extremely small, and becomes the same as or substantially the same as the actual refrigerant evaporation temperature TXO.

This situation is shown in FIG. In the figure, the broken line L1 is the refrigerant evaporation temperature TXObase of the outdoor heat exchanger 7 when there is no frost when offset correction is performed, and the broken line L2 is the outdoor heat exchanger 7 when there is no frost when no correction is performed. Refrigerant evaporation temperature TXObase (similar to FIG. 9). By correcting the refrigerant evaporation temperature TXObase of the outdoor heat exchanger 7 when there is no frost in this way, the error LRN (offset correction amount) is determined, and after correction based on that, the state is the same as in FIG. It can be seen that the frost formation of the outdoor heat exchanger 7 can be detected without any trouble based on the difference ΔTXO, the above-mentioned predetermined value dTXOFST, and the predetermined time t3.

If the error LRN is 0 or more in step S7, the heat pump controller 32 proceeds to step S8, sets LRN = 0, and does not perform offset correction of the refrigerant evaporation temperature TXObase of the outdoor heat exchanger 7 at the time of no frost formation ( No offset correction). The fact that the error LRN is 0 or more means that the outdoor heat exchanger 7 has frost from the initial stage of startup, and the refrigerant evaporation temperature TXO is lower than the refrigerant evaporation temperature TXObase of the outdoor heat exchanger 7 from the initial stage of startup to the time of no frost formation. This is because it is considered to be.

Further, if the above-mentioned difference ΔPT does not fall within the predetermined value within the predetermined timeout period t6 from the initial start-up and the timeout t6 period elapses in step S5, the heat pump controller 32 proceeds to step S6 and LRN = 0. Similarly, the offset correction of the refrigerant evaporation temperature TXObase of the outdoor heat exchanger 7 at the time of no frost is not performed (no offset correction). That is, the initial start-up coincides with or substantially coincides with the period from the start-up (start of operation) of the heating mode to the elapse of the timeout period t6.

FIG. 11 is a transition diagram of frost formation determination of the outdoor heat exchanger 7 by the heat pump controller 32. In the figure, SS1 shows the state before the calculation of the offset correction amount, SS2 shows the state during the calculation of the offset correction amount, and SS3 shows the state after the calculation of the offset correction amount, and the transition from SS1 to SS2 occurs at the start of the heating mode. After the frost formation determination is permitted, the offset correction amount is calculated, and the transition from SS2 to SS3 is performed when the offset correction amount is determined or a timeout occurs. Then, when the heating mode is stopped, SS2 or SS3 returns to SS1 (frosting determination is not permitted). That is, the heat pump controller 32 calculates the offset correction amount each time the heating mode is started (started).

As described above, the heat pump controller 32 has the refrigerant evaporation temperature TXObase of the outdoor heat exchanger 7 at the time of no frost, or the outdoor heat exchanger 7 at the time of no frost, based on the environmental conditions and / or the index indicating the operating condition. In addition to estimating the refrigerant evaporation pressure PXObase of the above, based on the refrigerant evaporation temperature TXO of the outdoor heat exchanger 7 in the heating mode and the refrigerant evaporation temperature TXObase of the outdoor heat exchanger 7 when there is no frost, or in the outdoor heat exchanger. Based on the refrigerant evaporation pressure PXO of 7 and the refrigerant evaporation pressure PXObase of the outdoor heat exchanger 7 when there is no frost, the frost formation on the outdoor heat exchanger 7 is determined. Then, at the initial stage of startup, between the refrigerant evaporation temperature TXObase of the outdoor heat exchanger 7 during non-frost and the refrigerant evaporation temperature TXO of the outdoor heat exchanger 7, or between the outdoor heat exchanger 7 during non-frost. If there is an error LRN on the side that does not detect frost formation between the refrigerant evaporation pressure PXObase and the refrigerant evaporation pressure PXO of the outdoor heat exchanger 7, this error LRN is reduced or canceled in the direction of no frost. Corrects the refrigerant evaporation temperature TXObase of the outdoor heat exchanger 7 or the refrigerant evaporation pressure PXObase of the outdoor heat exchanger 7 when there is no frost. As a result, the refrigerant evaporation temperature TXObase of the outdoor heat exchanger 7 at the time of no frost, or the refrigerant evaporation pressure PXObase of the outdoor heat exchanger 7 at the time of no frost, which is actually estimated due to the variation of parts such as the temperature sensor. Even if an error LRN occurs between the refrigerant evaporation temperature TXO of the outdoor heat exchanger 7 and the refrigerant evaporation pressure PXO, this is reduced or canceled to promote the progress of frost formation in the outdoor heat exchanger 7. It will be possible to detect accurately.

Then, when the heat pump controller 32 determines that the outdoor heat exchanger 7 has frosted, the compressor 2 is stopped, or the above-mentioned defrosting operation for removing the frost on the outdoor heat exchanger 7 is performed. By doing so, it becomes possible to appropriately protect the equipment and defrost the outdoor heat exchanger 7 to ensure the comfort in the vehicle interior.

In this case, the heat pump controller 32 is in a state where the refrigerant evaporation temperature TXO of the outdoor heat exchanger 7 is lower than the refrigerant evaporation temperature TXObase of the outdoor heat exchanger 7 when there is no frost, and the difference ΔTXO becomes a predetermined value or more. Is continued for a predetermined time (t3), or the refrigerant evaporation pressure PXO of the outdoor heat exchanger 7 is lower than the refrigerant evaporation pressure PXObase of the outdoor heat exchanger 7 when there is no frost, and the difference ΔPXO is equal to or more than the predetermined value. If this condition continues for a predetermined time (t4), it is determined that the outdoor heat exchanger 7 has been frosted. Therefore, erroneous determination due to the influence of disturbance or the like is eliminated, and the frost formation of the outdoor heat exchanger 7 progresses. Will be able to be detected with high accuracy.

In particular, the heat pump controller 32 calculates the difference ΔTXO or the difference ΔPXO a plurality of times within the predetermined period t5 at the initial stage of startup, and the difference ΔPT between the largest difference ΔTXOmax and the smallest difference ΔTXOmin within the predetermined period t5, or It is determined whether or not the difference ΔPP between the largest difference ΔPXOmax and the smallest difference ΔPXOmin within the predetermined period t5 is within the predetermined value, and when it is within the predetermined value, a plurality of differences ΔTXO within the predetermined period t5, or , The error LRN is determined based on a plurality of differences ΔPXO within the predetermined period t5. This makes it possible to eliminate the erroneous calculation of the error LRN in an unstable operating condition at the initial stage of startup and to realize the determination of the error LRN in a stable condition.

However, if the difference ΔPT or the difference ΔPP does not fall within the predetermined value within the predetermined timeout period, the heat pump controller 32 corrects the refrigerant evaporation temperature TXObase of the outdoor heat exchanger 7 at the time of no frost due to the error LRN. Alternatively, since the refrigerant evaporation pressure PXObase of the outdoor heat exchanger 7 is not corrected due to the error LRN when there is no frost, the error LRN cannot be determined for an unnecessarily long period of time, and the frost formation determination of the outdoor heat exchanger 7 is made. It becomes possible to avoid the inconvenience that is not performed.

Next, FIG. 13 shows a block diagram of the vehicle air conditioner 1 of another embodiment to which the present invention is applied. In this figure, those shown by the same reference numerals as those in FIG. 1 have the same or similar functions. In the case of this embodiment, the outlet of the supercooling unit 16 is connected to the check valve 18, and the outlet of the check valve 18 is connected to the refrigerant pipe 13B. The check valve 18 has a forward direction on the refrigerant pipe 13B (indoor expansion valve 8) side.

Further, the refrigerant pipe 13E on the outlet side of the radiator 4 is branched in front of the outdoor expansion valve 6, and the branched refrigerant pipe (hereinafter referred to as the second bypass pipe) 13F is the solenoid valve 22 (for dehumidification). It is communicated with the refrigerant pipe 13B on the downstream side of the check valve 18 via the check valve 18. Further, an evaporation pressure adjusting valve 70 is connected to the refrigerant pipe 13C on the outlet side of the heat absorber 9 on the downstream side of the refrigerant of the internal heat exchanger 19 and on the upstream side of the refrigerant from the confluence with the refrigerant pipe 13D. .. The solenoid valve 22 and the evaporation pressure adjusting valve 70 are also connected to the output of the heat pump controller 32. The bypass device 45 including the bypass pipe 35, the solenoid valve 30, and the solenoid valve 40 in FIG. 1 of the above-described embodiment is not provided. Others are the same as in FIG. 1, and the description thereof will be omitted.

With the above configuration, the operation of the vehicle air conditioner 1 of this embodiment will be described. In this embodiment, the heat pump controller 32 switches and executes each operation mode of the heating mode, the dehumidifying heating mode, the internal cycle mode, the dehumidifying cooling mode, the cooling mode, and the auxiliary heater independent mode (MAX cooling mode exists in this embodiment). do not do). Since the operation and the flow of the refrigerant when the heating mode, the dehumidifying cooling mode, and the cooling mode are selected, and the auxiliary heater independent mode are the same as those in the above-described embodiment (Example 1), the description thereof will be omitted. However, in this embodiment (Example 2), the solenoid valve 22 is closed in the heating mode, the dehumidifying cooling mode, and the cooling mode.

(12) Dehumidifying and heating mode of the vehicle air conditioner 1 shown in FIG. 13 On the other hand, when the dehumidifying and heating mode is selected, the heat pump controller 32 opens the solenoid valve 21 (for heating) in this embodiment (Example 2). , Close the solenoid valve 17 (for cooling). In addition, the solenoid valve 22 (for dehumidification) is opened. Then, the compressor 2 is operated. The air conditioning controller 20 operates the blowers 15 and 27, and the air mix damper 28 basically blows out all the air in the air flow passage 3 that has been blown out from the indoor blower 27 and passed through the heat absorber 9 to heat the heat exchange passage 3A for heating. The auxiliary heater 23 and the radiator 4 are ventilated, but the air volume is also adjusted.

As a result, the high-temperature and high-pressure gas refrigerant discharged from the compressor 2 flows into the radiator 4 from the refrigerant pipe 13G. Since the air in the air flow passage 3 flowing into the heat exchange passage 3A for heating is ventilated to the radiator 4, the air in the air flow passage 3 is heated by the high temperature refrigerant in the radiator 4, while the radiator The refrigerant in 4 is deprived of heat by air, cooled, and condensed.

The refrigerant liquefied in the radiator 4 exits the radiator 4 and then reaches the outdoor expansion valve 6 via the refrigerant pipe 13E. The refrigerant that has flowed into the outdoor expansion valve 6 is decompressed there, and then flows into the outdoor heat exchanger 7. The refrigerant that has flowed into the outdoor heat exchanger 7 evaporates and draws heat from the outside air that is ventilated by the outdoor blower 15 or by running. That is, the refrigerant circuit R serves as a heat pump. Then, the low-temperature refrigerant that has exited the outdoor heat exchanger 7 enters the accumulator 12 from the refrigerant pipe 13C via the refrigerant pipe 13A, the electromagnetic valve 21, and the refrigerant pipe 13D, and after gas-liquid separation there, the gas refrigerant is used in the compressor 2. Repeat the circulation sucked into.

Further, a part of the condensed refrigerant flowing through the refrigerant pipe 13E via the radiator 4 is diverted, and reaches the indoor expansion valve 8 from the second bypass pipe 13F and the refrigerant pipe 13B via the solenoid valve 22 via the internal heat exchanger 19. Will be. After the refrigerant is depressurized by the indoor expansion valve 8, it flows into the heat absorber 9 and evaporates. Due to the endothermic action at this time, the moisture in the air blown out from the indoor blower 27 condenses and adheres to the heat absorber 9, so that the air is cooled and dehumidified.

The refrigerant evaporated in the heat absorber 9 joins the refrigerant from the refrigerant pipe 13D in the refrigerant pipe 13C through the internal heat exchanger 19 and the evaporation pressure adjusting valve 70 in that order, and then is sucked into the compressor 2 through the accumulator 12. repeat. The air dehumidified by the heat absorber 9 is reheated in the process of passing through the radiator 4, so that the dehumidifying and heating of the vehicle interior is performed.

The air conditioning controller 20 transmits the target heater temperature TCO (target value of radiator outlet temperature TCI) calculated from the target outlet temperature TAO to the heat pump controller 32. The heat pump controller 32 calculates the target radiator pressure PCO (target value of the radiator pressure PCI) from the target heater temperature TCO, and the target radiator pressure PCO and the refrigerant of the radiator 4 detected by the radiator pressure sensor 47. The rotation speed NC of the compressor 2 is controlled based on the pressure (radiator pressure PCI; high pressure of the refrigerant circuit R), and the heating by the radiator 4 is controlled. Further, the heat pump controller 32 controls the valve opening degree of the outdoor expansion valve 6 based on the temperature Te of the heat absorber 9 detected by the heat absorber temperature sensor 48 and the target heat absorber temperature TEO transmitted from the air conditioning controller 20. Further, the heat pump controller 32 opens / closes the evaporation pressure adjusting valve 70 (expands the flow path) / closes (the small amount of refrigerant flows) based on the temperature Te of the heat absorber 9 detected by the heat absorber temperature sensor 48, and the heat pump controller 9 Prevents the inconvenience of freezing due to the temperature of the

(13) Internal Cycle Mode of Vehicle Air Conditioning Device 1 of FIG. 13 In the internal cycle mode, the heat pump controller 32 fully closes the outdoor expansion valve 6 (fully closed position) in the dehumidifying and heating mode. The solenoid valve 21 is closed. By closing the outdoor expansion valve 6 and the solenoid valve 21, the inflow of the refrigerant into the outdoor heat exchanger 7 and the outflow of the refrigerant from the outdoor heat exchanger 7 are prevented, so that the radiator 4 All of the condensed refrigerant flowing through the refrigerant pipe 13E flows through the solenoid valve 22 to the second bypass pipe 13F. Then, the refrigerant flowing through the second bypass pipe 13F reaches the indoor expansion valve 8 from the refrigerant pipe 13B via the internal heat exchanger 19. After the refrigerant is depressurized by the indoor expansion valve 8, it flows into the heat absorber 9 and evaporates. Due to the endothermic action at this time, the moisture in the air blown out from the indoor blower 27 condenses and adheres to the heat absorber 9, so that the air is cooled and dehumidified.

The refrigerant evaporated in the heat absorber 9 flows through the refrigerant pipe 13C in sequence through the internal heat exchanger 19 and the evaporation pressure adjusting valve 70, and repeats the circulation of being sucked into the compressor 2 through the accumulator 12. Since the air dehumidified by the endothermic 9 is reheated in the process of passing through the radiator 4, dehumidifying and heating the interior of the vehicle is performed, but in this internal cycle mode, the air flow on the indoor side. Since the refrigerant is circulated between the radiator 4 (heat dissipation) and the endothermic 9 (endothermic) in the path 3, heat from the outside air is not pumped up, and heating for the power consumed by the compressor 2 is not performed. The ability is demonstrated. Since the entire amount of the refrigerant flows through the heat absorber 9 that exerts a dehumidifying action, the dehumidifying capacity is higher than that of the dehumidifying and heating mode, but the heating capacity is lower.

The air conditioning controller 20 transmits the target heater temperature TCO (target value of radiator outlet temperature TCI) calculated from the target outlet temperature TAO to the heat pump controller 32. The heat pump controller 32 calculates the target radiator pressure PCO (target value of the radiator pressure PCI) from the transmitted target heater temperature TCO, and the target radiator pressure PCO and the radiator 4 detected by the radiator pressure sensor 47. The rotation speed NC of the compressor 2 is controlled based on the refrigerant pressure (radiator pressure PCI; high pressure of the refrigerant circuit R), and the heating by the radiator 4 is controlled.

(14) Defrosting determination control of the outdoor heat exchanger in the embodiment of FIG. 13 Then, in this embodiment as well, the frosting determination of the outdoor heat exchanger 7 is performed in the same manner as in (11) above, and when there is no frost. The offset correction is performed by the error LRN of the refrigerant evaporation temperature TXObase of the outdoor heat exchanger 7 and the refrigerant evaporation pressure PXObase of the outdoor heat exchanger 7 at the time of no frost. In the case of this embodiment, the dehumidifying heating mode is performed. Even in (including the internal cycle mode), the refrigerant evaporates in the outdoor heat exchanger 7 and frosting occurs. Therefore, in these operation modes as well, the frosting determination and the offset correction of the error LRN are performed as in the heating mode. As a result, similarly, the progress of frost formation in the outdoor heat exchanger 7 can be accurately detected.

The numerical values and the like shown in each embodiment are not limited to those, and should be appropriately set according to the device to be applied. Further, the auxiliary heating device is not limited to the auxiliary heater 23 shown in the embodiment, but is used in a heat medium circulation circuit that circulates a heat medium heated by the heater to heat the air in the air flow passage 3, or an engine. A heater core or the like that circulates the heated radiator water may be used.

1 Vehicle air conditioner 2 Compressor 3 Air flow passage 4 Heater 6 Outdoor expansion valve 7 Outdoor heat exchanger 8 Indoor expansion valve 9 Heat absorber 10 HVAC unit 11 Control device 20 Air conditioning controller 23 Auxiliary heater (auxiliary heating device)
27 Indoor blower (blower fan)
28 Air mix damper 32 Heat pump controller 65 Vehicle communication bus R Refrigerant circuit

Claims (6)

A compressor that compresses the refrigerant and
An air flow passage through which the air supplied to the passenger compartment flows, and
A radiator for radiating the refrigerant and heating the air supplied from the air flow passage to the passenger compartment,
An outdoor heat exchanger provided outside the vehicle interior to absorb heat from the refrigerant,
Equipped with a control device
With the control device, at least the refrigerant discharged from the compressor is radiated by the radiator, the radiated refrigerant is depressurized, and then heat is absorbed by the outdoor heat exchanger to heat the vehicle interior.
In a vehicle air conditioner that determines frost on the outdoor heat exchanger based on the refrigerant evaporation temperature TXO of the outdoor heat exchanger and the refrigerant evaporation temperature TXObase of the outdoor heat exchanger when there is no frost.
The control device estimates the refrigerant evaporation temperature TXObase of the outdoor heat exchanger at the time of no frost formation based on the environmental conditions and / or the index indicating the operating condition, and also
If there is an error LRN to the side that does not detect frost formation between the refrigerant evaporation temperature TXObase of the outdoor heat exchanger and the refrigerant evaporation temperature TXO of the outdoor heat exchanger at the initial stage of startup, An air conditioner for a vehicle, characterized in that the refrigerant evaporation temperature TXObase of the outdoor heat exchanger at the time of no frost is corrected in a direction of reducing or canceling the error LRN. A compressor that compresses the refrigerant and
An air flow passage through which the air supplied to the passenger compartment flows, and
A radiator for radiating the refrigerant and heating the air supplied from the air flow passage to the passenger compartment,
An outdoor heat exchanger provided outside the vehicle interior to absorb heat from the refrigerant,
Equipped with a control device
With the control device, at least the refrigerant discharged from the compressor is radiated by the radiator, the radiated refrigerant is depressurized, and then heat is absorbed by the outdoor heat exchanger to heat the vehicle interior.
In a vehicle air conditioner that determines frost on the outdoor heat exchanger based on the refrigerant evaporation pressure PXO of the outdoor heat exchanger and the refrigerant evaporation pressure PXObase of the outdoor heat exchanger when there is no frost.
The control device estimates the refrigerant evaporation pressure PXObase of the outdoor heat exchanger at the time of no frost formation based on the environmental conditions and / or the index indicating the operating condition, and also
If there is an error LRN to the side where frost formation is not detected between the refrigerant evaporation pressure PXObase of the outdoor heat exchanger and the refrigerant evaporation pressure PXO of the outdoor heat exchanger at the initial stage of startup, An air conditioner for a vehicle, characterized in that the refrigerant evaporation pressure PXObase of the outdoor heat exchanger at the time of no frost is corrected in a direction of reducing or canceling the error LRN. In the control device, the refrigerant evaporation temperature TXO of the outdoor heat exchanger is lower than the refrigerant evaporation temperature TXObase of the outdoor heat exchanger at the time of no frost, and the difference ΔTXO becomes a predetermined value or more for a predetermined time. When it continues, or when the refrigerant evaporation pressure PXO of the outdoor heat exchanger is lower than the refrigerant evaporation pressure PXObase of the outdoor heat exchanger at the time of no frost, the difference ΔPXO becomes a predetermined value or more. The vehicle air conditioner according to claim 1 or 2, wherein it is determined that the outdoor heat exchanger has been frosted when the time is continued. At the initial stage of activation, the control device calculates the difference ΔTXO or the difference ΔPXO a plurality of times within a predetermined period, and the difference ΔPT between the largest difference ΔTXO and the smallest difference ΔTXO within the predetermined period, or the predetermined difference. It is determined whether or not the difference ΔPP between the largest difference ΔPXO and the smallest difference ΔPXO in the period is within the predetermined value, and when it is within the predetermined value, the plurality of said differences ΔTXO within the predetermined period or the said The vehicle air conditioner according to claim 3, wherein the error LRN is determined based on a plurality of the differences ΔPXO within a predetermined period. When the difference ΔPT or the difference ΔPP does not fall within a predetermined value within a predetermined timeout period, the control device evaporates the refrigerant of the outdoor heat exchanger in the direction of canceling the error LRN at the time of no frost. The vehicle air conditioner according to claim 4, wherein the temperature TXObase is not corrected or the refrigerant evaporation pressure PXObase of the outdoor heat exchanger is not corrected in the direction of canceling the error LRN at the time of no frost. .. When the control device determines that the outdoor heat exchanger has frosted, the compressor stops the compressor or executes a predetermined defrosting operation for removing the frost on the outdoor heat exchanger. The vehicle air conditioner according to any one of claims 1 to 5, characterized in that.

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