WO2018088124A1 - Vehicular air conditioner - Google Patents

Abstract

Provided is a vehicular air conditioner capable of eliminating the inconvenience that a compressor is operated in a state where the operational efficiency is low. The progress of frost formation on an outdoor heat exchanger 7 is determined on the basis of the difference ΔTXO = TXObase - TXO between refrigerant evaporation temperature TXO and refrigerant evaporation temperature TXObase when the refrigerant evaporation temperature TXO of the outdoor heat exchanger 7 becomes lower than the refrigerant evaporation temperature TXObase of the outdoor heat exchanger during no frost formation, or on the basis of the difference ΔPXO between refrigerant evaporation pressure PXO and refrigerant evaporation pressure PXObase during no frost formation. If the state in which the frost formation on the outdoor heat exchanger 7 is proceeding is maintained for a predetermined time period, a compressor 2 is stopped.

Description

Air conditioner for vehicles

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

Recently, hybrid vehicles and electric vehicles have become popular due to the emergence of environmental problems. 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 and dissipates the refrigerant, and is provided on the vehicle exterior side. An outdoor heat exchanger that absorbs refrigerant is provided, and a heating mode is developed in which the refrigerant discharged from the compressor dissipates heat in the radiator, and the refrigerant dissipated in the radiator absorbs heat in the outdoor heat exchanger. (For example, refer to Patent Document 1).

JP 2014-94676 A

Here, since the outdoor heat exchanger absorbs heat from the outside air in the heating mode, frost formation occurs in the outdoor heat exchanger. If the operation of the compressor is continued in a state in which frost formation on the outdoor heat exchanger has progressed, the heat absorption capability from the outside air is reduced, so that the operation efficiency is significantly reduced. Moreover, defrosting of the outdoor heat exchanger becomes difficult due to excessive frost formation.
In addition, even when the operation of the compressor is continued in a state where the temperature and pressure of the refrigerant sucked into the compressor is lowered due to a decrease in the outside air temperature or the like, the operation efficiency is remarkably high because the compressor speed cannot be increased sufficiently. descend.
The present invention has been made to solve the conventional technical problems, and provides an air conditioning apparatus for a vehicle that can eliminate the inconvenience of operating the compressor in a situation where the operating efficiency is lowered. For the purpose.

An air conditioner for a vehicle according to a first aspect of the present invention includes a compressor that compresses a refrigerant, an air flow passage through which air supplied to the vehicle interior flows, and air that radiates the refrigerant and supplies the refrigerant to the vehicle interior from the air flow passage. A heat radiator that heats the vehicle, an outdoor heat exchanger that is provided outside the passenger compartment to absorb the refrigerant, and a control device, and at least the refrigerant discharged from the compressor is supplied to the heat radiator by the control device. The refrigerant is radiated, and the radiated refrigerant is depressurized, and then the outdoor heat exchanger absorbs heat to heat the vehicle interior. The control device is configured such that the refrigerant evaporating temperature TXO of the outdoor heat exchanger is not frosted. The difference ΔTXO = TXObase−T between the refrigerant evaporation temperature TXO of the outdoor heat exchanger when it is lower than the refrigerant evaporation temperature TXObase of the outdoor heat exchanger and the refrigerant evaporation temperature TXObase of the outdoor heat exchanger when there is no frost Or when the refrigerant evaporating pressure PXO of the outdoor heat exchanger is lower than the refrigerant evaporating pressure PXObase of the outdoor heat exchanger at the time of no frosting and at the time of no frosting Based on the difference ΔPXO = PXObase−PXO with the refrigerant evaporation pressure PXObase of the outdoor heat exchanger at, the progress of frost formation on the outdoor heat exchanger was determined and the frost formation on the outdoor heat exchanger proceeded The compressor is stopped when the state continues for a predetermined time.
The air conditioning apparatus for a vehicle according to a second aspect of the present invention is the air conditioning apparatus for a vehicle according to the second aspect, wherein the control apparatus is configured such that the refrigerant evaporation temperature TXObase of the outdoor heat exchanger at the time of non-frosting based on the environmental condition and / or the index indicating the operation state Or the refrigerant | coolant evaporation pressure PXObase of the outdoor heat exchanger at the time of no frost formation is estimated, It is characterized by the above-mentioned.
According to a third aspect of the present invention, there is provided the vehicle air conditioner according to the first aspect, wherein the control device is configured such that when the difference ΔTXO or the difference ΔPXO is greater than the first threshold value A1 continues for the first predetermined time t1. It is characterized by stopping.
According to a fourth aspect of the present invention, there is provided the vehicle air conditioner according to the first aspect, wherein the control device is configured such that the difference ΔTXO or the state where the difference ΔPXO is larger than the second threshold A2 smaller than the first threshold A1 is first predetermined time. The compressor is stopped when the second predetermined time t2 longer than t1 is continued.
In the vehicle air conditioner of the invention of claim 5, in each of the above inventions, the control device can determine the progress of frost formation on the outdoor heat exchanger when the heating capacity of the radiator satisfies the required capacity. It is characterized by not stopping the compressor based on it.
According to a sixth aspect of the present invention, there is provided a vehicle air conditioner according to the above-described invention, wherein the control device stops the compressor based on the determination of the progress state of frost formation on the outdoor heat exchanger until a predetermined time has elapsed after activation. It is characterized by not performing.
According to a seventh aspect of the present invention, there is provided an air conditioning apparatus for a vehicle according to each of the above inventions, wherein the controller stops the compressor based on the determination of the progress of frosting on the outdoor heat exchanger, and then removes the outdoor heat exchanger. The compressor is prohibited from starting until it is frosted.
An air conditioner for a vehicle according to an eighth aspect of the invention includes a compressor that compresses a refrigerant, an air flow passage through which air supplied to the vehicle interior flows, and air that radiates the refrigerant and supplies the refrigerant to the vehicle interior from the air flow passage. A heat radiator that heats the vehicle, an outdoor heat exchanger that is provided outside the passenger compartment to absorb the refrigerant, and a control device, and at least the refrigerant discharged from the compressor is supplied to the heat radiator by the control device. After the heat is radiated and the radiated refrigerant is depressurized, the heat is absorbed by the outdoor heat exchanger to heat the vehicle interior, and the control device is configured such that the suction refrigerant temperature Ts of the compressor is a first predetermined value Ts1. When it becomes lower, or when the suction refrigerant pressure Ps of the compressor becomes lower than the first predetermined value Ps1, the limit control for decelerating the rotation speed NC of the compressor is executed, and in this limit control state, Rotation speed NC of the compressor is If lower than the value NC1 continues for a predetermined time, characterized by stopping the compressor.
According to a ninth aspect of the present invention, there is provided a vehicle air conditioner according to the above invention, wherein the control device is in a restricted control state based on the suction refrigerant temperature Ts or the suction refrigerant pressure Ps of the compressor until a predetermined time elapses after activation. The compressor is not stopped. According to a tenth aspect of the present invention, there is provided a vehicle air conditioner according to the above invention, wherein the control device stops the compressor based on the determination of the suction refrigerant temperature Ts or the suction refrigerant pressure Ps of the compressor, and then the compressor. Until the suction refrigerant temperature Ts becomes higher than a second predetermined value Ts2 that is higher than the first predetermined value Ts1, or from the second predetermined value Ps2 that the suction refrigerant pressure Ps of the compressor is higher than the first predetermined value Ps1. Until the temperature rises or until the outside air temperature becomes higher than a predetermined value, starting of the compressor is prohibited.
The vehicle air conditioner according to an eleventh aspect of the present invention includes the auxiliary heating device provided in the air flow passage in each of the above inventions, and the control device is based on the determination of the progress state of frost formation on the outdoor heat exchanger. When the compressor is stopped, or when the compressor is stopped based on the determination of the suction refrigerant temperature Ts or the suction refrigerant pressure Ps of the compressor, the vehicle interior is heated by the auxiliary heating device. .

According to the first aspect of the present invention, the compressor for compressing the refrigerant, the air flow passage through which the air supplied to the vehicle interior flows, and the air supplied to the vehicle interior from the air flow passage by radiating the refrigerant are heated. A radiator, an outdoor heat exchanger provided outside the passenger compartment to absorb the refrigerant, and a control device, and by this control device, at least the refrigerant discharged from the compressor is radiated by the radiator, In a vehicle air conditioner that heats the interior of a vehicle by depressurizing the radiated refrigerant and then heat-absorbing it in the outdoor heat exchanger, the control device is configured so that the refrigerant evaporation temperature TXO of the outdoor heat exchanger is Difference ΔTXO = TXObase−T between the refrigerant evaporation temperature TXO of the outdoor heat exchanger when it is lower than the refrigerant evaporation temperature TXObase of the outdoor heat exchanger and the refrigerant evaporation temperature TXObase of the outdoor heat exchanger when there is no frost formation Or when the refrigerant evaporating pressure PXO of the outdoor heat exchanger is lower than the refrigerant evaporating pressure PXObase of the outdoor heat exchanger at the time of no frosting and at the time of no frosting Based on the difference ΔPXO = PXObase−PXO with the refrigerant evaporation pressure PXObase of the outdoor heat exchanger at, the progress of frost formation on the outdoor heat exchanger was determined and the frost formation on the outdoor heat exchanger proceeded Since the compressor is stopped when the state continues for a predetermined time, the compressor can be stopped in a state where frost formation on the outdoor heat exchanger has progressed.
As a result, it is possible to prevent the operation of the compressor from being continued in a situation where the operation efficiency is reduced due to the frost formation of the outdoor heat exchanger, and to contribute to energy saving. It also becomes possible to eliminate the problem of device reliability degradation and defrosting due to frost formation.
In this case, the control device as in the second aspect of the invention is configured so that the refrigerant evaporating temperature TXObase of the outdoor heat exchanger at the time of no frosting or the time of no frosting is determined based on the environmental condition and / or the index indicating the operation state. By estimating the refrigerant evaporation pressure PXObase of the outdoor heat exchanger at, the progress of frost formation of the outdoor heat exchanger can be accurately detected.
According to a third aspect of the present invention, when the control device causes the difference ΔTXO or the difference ΔPXO to be greater than the first threshold value A1 continues for the first predetermined time t1, the outdoor heat is reduced by stopping the compressor. When excessive frosting of the exchanger proceeds in a relatively short time, the compressor can be stopped quickly.
On the other hand, as in the fourth aspect of the present invention, the control device determines that the difference ΔTXO or the state where the difference ΔPXO is larger than the second threshold A2 smaller than the first threshold A1 is longer than the first predetermined time t1. If the compressor is stopped when the time t2 is continued, the compressor can be surely stopped even when the moderate frost formation of the outdoor heat exchanger continues for a relatively long time. become.
However, in the situation where the heating capacity of the radiator satisfies the required capacity by the control device as in the invention of claim 5, the compressor is not stopped based on the determination of the progress state of frost formation on the outdoor heat exchanger. If it does in this way, stop of a compressor will be prohibited in the situation where the heating capability by a radiator is achieved, and comfortable heating of a vehicle interior can be continued as it is.
Further, if the control device as in the sixth aspect of the invention prevents the compressor from being stopped based on the determination of the progress of frost formation on the outdoor heat exchanger until a predetermined time has elapsed after the start, It becomes possible to eliminate erroneous determination in the unstable driving state immediately after.
Furthermore, after stopping the compressor based on the determination of the progress of frost formation on the outdoor heat exchanger by the control device as in the invention of claim 7, the compressor is operated until the outdoor heat exchanger is defrosted. If the start is prohibited, the restart of the compressor in a state where frost remains in the outdoor heat exchanger is prohibited, thereby avoiding inconvenience that frost that is hard to melt is generated in advance. Will be able to.
According to invention of Claim 8, in order to heat the compressor which compresses a refrigerant | coolant, the air flow path through which the air supplied to a vehicle interior distribute | circulates, and the air which thermally radiates a refrigerant | coolant and is supplied into a vehicle interior from an air flow path A radiator, an outdoor heat exchanger provided outside the passenger compartment to absorb the refrigerant, and a control device, and by this control device, at least the refrigerant discharged from the compressor is radiated by the radiator, In the vehicle air conditioner that heats the interior of the vehicle by depressurizing the radiated refrigerant and then absorbing the heat with an outdoor heat exchanger, the control device has a suction refrigerant temperature Ts of the compressor that is lower than a first predetermined value Ts1. Or when the suction refrigerant pressure Ps of the compressor becomes lower than the first predetermined value Ps1, the limit control for decelerating the rotation speed NC of the compressor is executed, and in this limit control state, the compressor The rotation speed NC is Since the compressor is stopped when the state lower than the fixed value NC1 continues for a predetermined time, the compressor is stopped in a state where the suction refrigerant temperature Ts or the suction refrigerant pressure Ps of the compressor is lowered due to a decrease in the outside air temperature or the like. You will be able to stop.
As a result, in a situation where the suction refrigerant temperature Ts and the suction refrigerant pressure Ps are low and the operation efficiency is lowered, it is possible to prevent the compressor from being continuously operated, and to contribute to energy saving, and the reliability of the equipment. It is possible to solve the problem of deterioration of the property.
At this time, when the suction refrigerant temperature Ts of the compressor becomes lower than the first predetermined value Ts1, or when the suction refrigerant pressure Ps of the compressor becomes lower than the first predetermined value Ps1, Since the restriction control is performed to decelerate the rotational speed NC of the compressor, it is possible to prevent the compressor from being stopped as much as possible by reducing the suction refrigerant temperature Ts or the suction refrigerant pressure Ps, or to extend the time until the compressor is stopped. As a result, it is possible to continue the comfortable heating of the passenger compartment as much as possible.
Further, as in the ninth aspect of the present invention, the control device does not stop the compressor in the restrictive control state based on the suction refrigerant temperature Ts or the suction refrigerant pressure Ps until a predetermined time has elapsed after starting. By doing so, it becomes possible to eliminate an erroneous stop of the compressor in an unstable operation state immediately after startup.
Further, after the controller stops the compressor based on the determination of the suction refrigerant temperature Ts of the compressor or the suction refrigerant pressure Ps as in the invention of claim 10, the suction refrigerant temperature Ts of the compressor is the first. Until it becomes higher than the second predetermined value Ts2 higher than the predetermined value Ts1, or until the suction refrigerant pressure Ps of the compressor becomes higher than the second predetermined value Ps2 higher than the first predetermined value Ps1, or the outside air temperature In the situation where the start-up of the compressor is prohibited until the value becomes higher than the predetermined value, the outside air temperature is low and the control speed is expected to be lower than the predetermined value NC1 due to the restriction control. It is possible to avoid the inconvenience that the compressor is frequently stopped and started without permitting the start of the compressor.
When the auxiliary heating device provided in the air flow passage is provided as in the invention of claim 11, the control device stops the compressor based on the determination of the progress of frost formation on the outdoor heat exchanger. Or, when the compressor is stopped based on the determination of the suction refrigerant temperature Ts or the suction refrigerant pressure Ps of the compressor, if the vehicle interior is heated by the auxiliary heating device, the operation efficiency of the compressor is reduced. Therefore, even when the compressor is stopped, the passenger compartment can be heated by the auxiliary heating device to reduce the passenger's discomfort.

It is a block diagram of the air conditioning apparatus for vehicles of one Embodiment to which this invention is applied. It is a block diagram of the control apparatus of the air conditioning apparatus for vehicles of FIG. It is a schematic diagram of the airflow path of the vehicle air conditioner of FIG. It is a control block diagram regarding the compressor control in the heating mode of the heat pump controller of FIG. It is a control block diagram regarding the compressor control in the dehumidification heating mode of the heat pump controller of FIG. It is a control block diagram regarding auxiliary heater (auxiliary heating apparatus) control in the dehumidification heating mode of the heat pump controller of FIG. It is a flowchart explaining the stop control of the compressor based on the frost formation determination 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. 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 PXObase and PXO. It is a flowchart explaining the stop control of the compressor based on the suction refrigerant temperature Ts by the heat pump controller of FIG. It is a timing chart explaining the stop control of the compressor based on the suction refrigerant temperature Ts by the heat pump controller of FIG. It is a block diagram of the air conditioning apparatus for vehicles of the other Example of this invention.

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

FIG. 1 shows a configuration diagram of a vehicle air conditioner 1 according to an embodiment of the present invention. A vehicle according to an 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 (both not shown), 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 a heating mode by a heat pump operation using a refrigerant circuit in an electric vehicle that cannot be heated by engine waste heat, and further includes a dehumidifying heating mode, a dehumidifying cooling mode, a cooling mode, Each operation mode of the MAX cooling mode (maximum cooling mode) and the auxiliary heater single mode is selectively executed.
The present invention is effective not only for electric vehicles but also for so-called hybrid vehicles that use an engine and an electric motor for traveling, and is also applicable to ordinary vehicles that run on an engine. Needless to say.
The vehicle air conditioner 1 according to the embodiment performs air conditioning (heating, cooling, dehumidification, and ventilation) in a vehicle interior of an electric vehicle, and includes an electric compressor 2 that compresses refrigerant and vehicle interior air. 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 the refrigerant, and supplies it to the vehicle interior. A radiator 4 for heating air, an outdoor expansion valve 6 (pressure reducing device) composed of an electric valve that decompresses and expands the refrigerant during heating, and functions as a radiator during cooling and serves as a radiator during heating, and an evaporator during heating An outdoor heat exchanger 7 that exchanges heat between the refrigerant and the outside air, an indoor expansion valve 8 (decompression device) that is an electric valve that decompresses and expands the refrigerant, and an air flow passage 3. Absorbs refrigerant during cooling and dehumidification A heat sink 9 for cooling caused by the air supplied to the vehicle interior is sucked from the cabin outside the accumulator 12 and the like are sequentially connected by a refrigerant pipe 13, the refrigerant circuit R is formed.
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 exchanges heat between the outside air and the refrigerant by forcibly passing outside air through the outdoor heat exchanger 7, so that the outdoor air blower 15 can also be used outdoors even when the vehicle is stopped (that is, the vehicle speed is 0 km / h). It is comprised so that external air may be ventilated by the heat exchanger 7. FIG.
The outdoor heat exchanger 7 has a receiver dryer section 14 and a supercooling section 16 sequentially on the downstream side of the refrigerant, and the refrigerant pipe 13A exiting from the outdoor heat exchanger 7 is received via an electromagnetic valve 17 opened during cooling. The refrigerant pipe 13 </ b> B connected to the dryer unit 14 and on the outlet side of the supercooling unit 16 is connected to the inlet side of the heat absorber 9 via the indoor expansion valve 8. In addition, the receiver dryer part 14 and the supercooling part 16 structurally constitute a part of the outdoor heat exchanger 7.
The refrigerant pipe 13B between the subcooling section 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 constitutes an internal heat exchanger 19 together. Thus, the refrigerant flowing into the indoor expansion valve 8 through the refrigerant pipe 13B is cooled (supercooled) by the low-temperature refrigerant that has exited the heat absorber 9.
Further, the refrigerant pipe 13A exiting from the outdoor heat exchanger 7 is branched into a refrigerant pipe 13D, and this branched refrigerant pipe 13D is downstream of the internal heat exchanger 19 via an electromagnetic valve 21 opened during heating. The refrigerant pipe 13C is connected in communication. The refrigerant pipe 13 </ b> C 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.
A 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) that is closed during dehumidification heating and MAX cooling described later. Yes. In this case, the refrigerant pipe 13G is branched into a bypass pipe 35 on the upstream side of the electromagnetic valve 30, and the bypass pipe 35 is opened by the electromagnetic valve 40 (which also constitutes a flow path switching device) during dehumidifying heating and MAX cooling. ) Through the refrigerant pipe 13E on the downstream side of the outdoor expansion valve 6. Bypass pipe 45, solenoid valve 30 and solenoid valve 40 constitute bypass device 45.
Since the bypass device 45 is configured by the bypass pipe 35, the electromagnetic valve 30, and the electromagnetic valve 40, the dehumidifying heating mode or the MAX for allowing the refrigerant discharged from the compressor 2 to directly flow into the outdoor heat exchanger 7 as will be described later. Switching between the cooling mode and the heating mode in which the refrigerant discharged from the compressor 2 flows into the radiator 4, the dehumidifying cooling mode, and the cooling mode can be performed smoothly.
The air flow passage 3 on the air upstream side of the heat absorber 9 is formed with each of an outside air inlet and an inside air inlet (represented by the inlet 25 in FIG. 1). 25 is provided with a suction switching damper 26 for switching the air introduced into the air flow passage 3 between the inside air (inside air circulation mode) which is air inside the passenger compartment and the outside air (outside air introduction mode) which is outside the passenger compartment. Yes. Furthermore, an indoor blower (blower fan) 27 for supplying the introduced inside air or outside air to the air flow passage 3 is provided on the air downstream side of the suction switching damper 26.
Moreover, in FIG. 1, 23 is an auxiliary heater as an auxiliary heating device 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 in the air flow passage 3 which is on the windward side (air upstream side) of the radiator 4 with respect to the air flow in the air flow passage 3. Is provided. When the auxiliary heater 23 is energized and generates heat, the air in the air flow passage 3 flowing into the radiator 4 through the heat absorber 9 is heated. In other words, the auxiliary heater 23 serves as a so-called heater core, which heats or complements the passenger compartment.
Here, the air flow passage 3 on the leeward side (air downstream side) from the heat absorber 9 of the HVAC unit 10 is partitioned by a partition wall 10A, and a heating heat exchange passage 3A and a bypass passage 3B that bypasses it are formed. The radiator 4 and the auxiliary heater 23 described above are disposed in the heating heat exchange passage 3A.
Further, 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 supplemented into the air flow passage 3 on the windward side of the auxiliary heater 23. An air mix damper 28 is provided for adjusting the rate of ventilation through the heating heat exchange passage 3A in which the heater 23 and the radiator 4 are disposed.
Further, the HVAC unit 10 on the leeward side of the radiator 4 includes a FOOT (foot) outlet 29A (first outlet) and a VENT (vent) outlet 29B (FOOT outlet 29A). For the outlet and the DEF outlet 29C, first outlets) and DEF (def) outlets 29C (second outlets) are formed. The FOOT air outlet 29A is an air outlet for blowing air under the feet in the passenger compartment, and is at the lowest position. Further, the VENT outlet 29B is an outlet for blowing out air near the driver's chest and face in the passenger compartment, and is located above the FOOT outlet 29A. The DEF air outlet 29C is an air outlet for blowing air to the inner surface of the windshield of the vehicle, and is located at the highest position above the other air outlets 29A and 29B.
The FOOT air outlet 29A, the VENT air outlet 29B, and the DEF air outlet 29C are respectively provided with a FOOT air outlet damper 31A, a VENT air outlet damper 31B, and a DEF air outlet damper 31C that control the amount of air blown out. It has been.
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 includes an air-conditioning controller 20 and a heat pump controller 32 each of which is a microcomputer that is an example of a computer including a processor, and these include a CAN (Controller Area Network) and a LIN (Local Interconnect Network). Is connected to a vehicle communication bus 65. 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.
The air conditioning controller 20 is a host controller that controls the air conditioning of the vehicle interior of the vehicle. 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 that detects the outside air humidity. The sensor 34, the HVAC suction temperature sensor 36 that detects the temperature of the air (suction air temperature Tas) that is sucked into the air flow passage 3 from the suction port 25 and flows into the heat sink 9, and the temperature of the air (inside air) in the passenger compartment An indoor air temperature sensor 37 that detects (indoor temperature Tin), an indoor air humidity sensor 38 that detects the humidity of the air in the vehicle interior, an indoor CO2 concentration sensor 39 that detects the carbon dioxide concentration in the vehicle interior, and the air blown into the vehicle interior. Detect air temperature
For example, a photosensor type solar radiation sensor 51 for detecting the amount of solar radiation into the passenger compartment, and a vehicle moving speed ( Each output of the vehicle speed sensor 52 for detecting the (vehicle speed) and an air conditioning (air conditioner) operation unit 53 for setting the switching of the set temperature and the operation mode are connected.
The output of the air conditioning controller 20 is connected to an outdoor blower 15, an indoor blower (blower fan) 27, a suction switching damper 26, an air mix damper 28, and air outlet dampers 31A to 31C. It is controlled by the controller 20.
The heat pump controller 32 is a controller that mainly controls the refrigerant circuit R. The input of the heat pump controller 32 includes a discharge temperature sensor 43 that detects a discharge refrigerant temperature Td of the compressor 2 and a suction refrigerant of the compressor 2. A suction pressure sensor 44 for detecting the pressure Ps, a suction temperature sensor 55 for detecting the suction refrigerant temperature Ts of the compressor 2, a radiator temperature sensor 46 for detecting the refrigerant temperature of the radiator 4 (radiator temperature TCI), A radiator pressure sensor 47 that detects the refrigerant pressure of the radiator 4 (radiator pressure PCI), a heat absorber temperature sensor 48 that detects the refrigerant temperature of the heat absorber 9 (heat absorber temperature Te), and the refrigerant pressure of the heat absorber 9 A heat absorber pressure sensor 49 that detects the temperature of the auxiliary heater 23, an auxiliary heater temperature sensor 50 that detects the temperature of the auxiliary heater 23 (auxiliary heater temperature Tptc), and the outlet of the outdoor heat exchanger 7 An outdoor heat exchanger temperature sensor 54 that detects the refrigerant temperature (outdoor heat exchanger temperature TXO), and an outdoor heat exchanger pressure sensor 56 that detects the refrigerant pressure (outdoor heat exchanger pressure PXO) at the outlet of the outdoor heat exchanger 7. Each output is connected.
The output of the heat pump controller 32 includes an outdoor expansion valve 6, an indoor expansion valve 8, an electromagnetic valve 30 (for reheating), an electromagnetic valve 17 (for cooling), an electromagnetic valve 21 (for heating), and an electromagnetic valve 40 (bypass). Are connected to each other and 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 send and receive data to and from the heat pump controller 32 via the vehicle communication bus 65. Be controlled.
The heat pump controller 32 and the air conditioning controller 20 transmit / receive data to / from each other via the vehicle communication bus 65, and control each device based on the output of each sensor and the setting 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 volumetric air volume Ga of air flowing into the air flow passage 3 (calculated by the air conditioning controller 20), and the air volume ratio SW ( The output from the air conditioning controller 53 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.
Next, the operation of the vehicle air conditioner 1 having the above-described configuration will be described. In this embodiment, the control device 11 (the air conditioning controller 20 and the heat pump controller 32) has each operation mode of heating mode, dehumidifying heating mode, dehumidifying cooling mode, cooling mode, MAX cooling mode (maximum cooling mode), and auxiliary heater single mode. Switch and execute. First, an outline of refrigerant flow and control 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 the manual operation (manual mode) to the air conditioning operation unit 53, the heat pump controller 32 opens the electromagnetic valve 21 (for heating) and the electromagnetic valve 17 (cooling). Close). Further, the electromagnetic valve 30 (for reheating) is opened, and the electromagnetic valve 40 (for bypass) is closed. Then, the compressor 2 is operated. The air conditioning controller 20 operates each of the blowers 15 and 27, and the air mix damper 28 basically heats all the air in the air flow passage 3 that is blown out from the indoor blower 27 and passes through the heat absorber 9 to the heat exchange passage 3A for heating. The auxiliary heater 23 and the radiator 4 are ventilated, but 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 electromagnetic valve 30. Since the air in the airflow passage 3 is passed through the radiator 4, the air in the airflow passage 3 is converted into the high-temperature refrigerant in the radiator 4 (when the auxiliary heater 23 operates, the auxiliary heater 23 and the radiator 4. On the other hand, the refrigerant in the radiator 4 is cooled by being deprived of heat by the air, and is condensed and liquefied.
The refrigerant liquefied in the radiator 4 exits the radiator 4 and then reaches the outdoor expansion valve 6 through the refrigerant pipe 13E. The refrigerant flowing into the outdoor expansion valve 6 is decompressed there and then flows into the outdoor heat exchanger 7. The refrigerant flowing into the outdoor heat exchanger 7 evaporates, and pumps up heat from the outside air that is ventilated by traveling or by the outdoor blower 15. That is, the refrigerant circuit R becomes a heat pump. Then, the low-temperature refrigerant exiting the outdoor heat exchanger 7 enters the accumulator 12 from the refrigerant pipe 13C through the refrigerant pipe 13A, the electromagnetic valve 21 and the refrigerant pipe 13D, and is separated into gas and liquid there. Repeated circulation inhaled. The air heated by the radiator 4 (when the auxiliary heater 23 is operated, the auxiliary heater 23 and the radiator 4) is blown out from the outlets 29A to 29C, so that the vehicle interior is heated. 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 number of revolutions NC of the compressor 2 is controlled based on the radiator pressure PCO and the refrigerant pressure of the radiator 4 detected by the radiator pressure sensor 47 (radiator pressure PCI. High pressure of the refrigerant circuit R). 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 of supercooling of the refrigerant at the outlet of the radiator 4 is controlled.
Further, in this heating mode, when the heating capability by the radiator 4 is insufficient with respect to the heating capability required for the cabin air conditioning, the heat pump controller 32 supplements the shortage with the heat generated by the auxiliary heater 23. The energization of the auxiliary heater 23 is controlled. Thereby, 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 disposed on the air upstream side of the radiator 4, the air flowing through the air flow passage 3 is vented to the auxiliary heater 23 before the radiator 4.
Here, when the auxiliary heater 23 is disposed on the air downstream side of the radiator 4, when the auxiliary heater 23 is configured by a PTC heater as in the embodiment, the temperature of the air flowing into the auxiliary heater 23 is determined by the radiator. 4, the resistance value of the PTC heater increases, the current value also decreases, and the heat generation amount decreases. However, by arranging the auxiliary heater 23 on the air upstream side of the radiator 4, Thus, the capacity of the auxiliary heater 23 composed of the PTC heater can be sufficiently exhibited.
(2) Dehumidification heating mode
Next, in the dehumidifying heating mode, the heat pump controller 32 opens the electromagnetic valve 17 and closes the electromagnetic valve 21. Further, the electromagnetic valve 30 is closed, the electromagnetic 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 each of the blowers 15 and 27, and the air mix damper 28 basically heats all the air in the air flow passage 3 that is blown out from the indoor blower 27 and passes through the heat absorber 9 to the heat exchange passage 3A for heating. The auxiliary heater 23 and the radiator 4 are ventilated, but the air volume is also adjusted.
Accordingly, 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 electromagnetic valve 40, and is connected to the refrigerant pipe on the downstream side of the outdoor expansion valve 6. 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 cooled and condensed by running there or by the outside air ventilated by the outdoor blower 15. The refrigerant that has exited the outdoor heat exchanger 7 sequentially flows from the refrigerant pipe 13 </ b> A through the electromagnetic valve 17 into the receiver dryer unit 14 and the supercooling unit 16. Here, the refrigerant is supercooled.
The refrigerant that has exited the supercooling section 16 of the outdoor heat exchanger 7 enters the refrigerant pipe 13 </ b> B, reaches the indoor expansion valve 8 through 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. The air blown out from the indoor blower 27 by the heat absorption action at this time is cooled, and 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 Dehumidified. The refrigerant evaporated in the heat absorber 9 reaches the accumulator 12 through the refrigerant pipe 13C through the internal heat exchanger 19, and repeats circulation that is sucked into the compressor 2 there through.
At this time, since the valve opening degree of the outdoor expansion valve 6 is fully closed, it is possible to suppress or prevent inconvenience that the refrigerant discharged from the compressor 2 flows backward from the outdoor expansion valve 6 into the radiator 4. It becomes. Thereby, the fall of a refrigerant | coolant circulation amount can be suppressed or eliminated and air-conditioning capability can be ensured now. Further, in this dehumidifying and 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 heating in the passenger compartment 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 a target heat absorber temperature TEO that is a target value of the heat absorber temperature Te calculated by the air conditioning controller 20. 2, and the auxiliary heater temperature Tptc detected by the auxiliary heater temperature sensor 50 and the above-described target heater temperature TCO (in this case, the target value of the auxiliary heater temperature Tptc) is used. By controlling energization (heating by heat generation), the air temperature of the air blown out from the outlets 29A to 29C by the heating by the auxiliary heater 23 while appropriately cooling and dehumidifying the air in the heat absorber 9 is controlled. Prevent the decline accurately. As a result, it is possible to control the temperature to an appropriate heating temperature while dehumidifying the air blown into the vehicle interior, and it is possible to realize comfortable and efficient dehumidification heating in the vehicle interior.
In addition, since the auxiliary heater 23 is disposed on the air upstream side of the radiator 4, the air heated by the auxiliary heater 23 passes through the radiator 4. In this dehumidifying heating mode, the refrigerant is supplied to the radiator 4. Therefore, the disadvantage that the radiator 4 absorbs heat from the air heated by the auxiliary heater 23 is also eliminated. That is, the temperature of the air blown out into the vehicle compartment by the radiator 4 is suppressed, and the COP is improved.
(3) Dehumidifying and cooling mode
Next, in the dehumidifying and cooling mode, the heat pump controller 32 opens the electromagnetic valve 17 and closes the electromagnetic valve 21. Further, the electromagnetic valve 30 is opened and the electromagnetic valve 40 is closed. Then, the compressor 2 is operated. The air conditioning controller 20 operates each of the blowers 15 and 27, and the air mix damper 28 basically heats all the air in the air flow passage 3 that is blown out from the indoor blower 27 and passes through the heat absorber 9 to 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 electromagnetic valve 30. Since the air in the air flow passage 3 is passed 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 and cooled, and condensates.
The refrigerant that has exited the radiator 4 reaches the outdoor expansion valve 6 through the refrigerant pipe 13E, and flows into the outdoor heat exchanger 7 through the outdoor expansion valve 6 that is controlled to open. The refrigerant flowing into the outdoor heat exchanger 7 is cooled and condensed by running there or by the outside air ventilated by the outdoor blower 15. The refrigerant that has exited the outdoor heat exchanger 7 sequentially flows from the refrigerant pipe 13 </ b> A through the electromagnetic valve 17 into the receiver dryer unit 14 and the supercooling unit 16. Here, the refrigerant is supercooled.
The refrigerant that has exited the supercooling section 16 of the outdoor heat exchanger 7 enters the refrigerant pipe 13 </ b> B, reaches the indoor expansion valve 8 through 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. Since the moisture in the air blown out from the indoor blower 27 by the heat absorption action at this time condenses and adheres to the heat absorber 9, the air is cooled and dehumidified.
The refrigerant evaporated in the heat absorber 9 reaches the accumulator 12 through the refrigerant pipe 13C through the internal heat exchanger 19, and repeats circulation that is sucked into the compressor 2 there through. In this dehumidifying and cooling mode, the heat pump controller 32 does not energize the auxiliary heater 23, so that the air that has been cooled and dehumidified by the heat absorber 9 is reheated in the process of passing through the radiator 4 (the heat dissipation capability is lower than that during heating). Is done. As a result, dehumidifying and cooling in the passenger compartment is performed.
The heat pump controller 32 determines the temperature of the compressor 2 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) that is the target value. The rotational speed NC is controlled. The heat pump controller 32 calculates the target radiator pressure PCO from the target heater temperature TCO described above, and the target radiator pressure PCO and the refrigerant pressure (radiator pressure PCI) of the radiator 4 detected by the radiator pressure sensor 47. Based on the high pressure of the refrigerant circuit R), the valve opening degree of the outdoor expansion valve 6 is controlled, and heating by the radiator 4 is controlled.
(4) Cooling mode
Next, in the cooling mode, the heat pump controller 32 fully opens the opening degree of the outdoor expansion valve 6 in the dehumidifying and cooling mode. Then, the compressor 2 is operated and the auxiliary heater 23 is not energized. The air-conditioning controller 20 operates each of the blowers 15 and 27, and the air mix damper 28 is blown from the indoor blower 27 and the air in the air flow passage 3 that has passed through the heat absorber 9 is used as the auxiliary heater 23 in the heating heat exchange passage 3A. And it is set as the state which adjusts the ratio ventilated by the radiator 4.
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 electromagnetic valve 30, and the refrigerant exiting the radiator 4 passes through the refrigerant pipe 13E and the outdoor expansion valve 6. To. 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 cooled by air or by outside air that is ventilated by the outdoor blower 15 and condensed. Liquefaction. The refrigerant that has exited the outdoor heat exchanger 7 sequentially flows from the refrigerant pipe 13 </ b> A through the electromagnetic valve 17 into the receiver dryer unit 14 and the supercooling unit 16. Here, the refrigerant is supercooled.
The refrigerant that has exited the supercooling section 16 of the outdoor heat exchanger 7 enters the refrigerant pipe 13 </ b> B, reaches the indoor expansion valve 8 through 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. The air blown out from the indoor blower 27 by the heat absorption action at this time is cooled. Further, moisture in the air condenses and adheres to the heat absorber 9.
The refrigerant evaporated in the heat absorber 9 reaches the accumulator 12 through the refrigerant pipe 13C through the internal heat exchanger 19, and repeats circulation that is sucked into the compressor 2 there through. Air that has been cooled and dehumidified by the heat absorber 9 is blown into the vehicle interior from each of the air outlets 29A to 29C (partly passes through the radiator 4 to exchange heat), thereby cooling the vehicle interior. Will be done. Further, in this cooling mode, the heat pump controller 32 uses the temperature of the heat absorber 9 (heat absorber temperature Te) detected by the heat absorber temperature sensor 48 and the above-described target heat absorber temperature TEO which is the target value of the compressor 2. The number of revolutions NC is controlled.
(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 electromagnetic valve 17 and closes the electromagnetic valve 21. Further, the electromagnetic valve 30 is closed, the electromagnetic 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 each of the blowers 15 and 27, and the air mix damper 28 is blown from the indoor blower 27 and the air in the air flow passage 3 passing through the heat absorber 9 is used as an auxiliary heater for the heating heat exchange passage 3 </ b> A. 23 and the rate of ventilation through the radiator 4 are adjusted.
Accordingly, 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 electromagnetic valve 40, and is connected to the refrigerant pipe on the downstream side of the outdoor expansion valve 6. 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 cooled and condensed by running there or by the outside air ventilated by the outdoor blower 15. The refrigerant that has exited the outdoor heat exchanger 7 sequentially flows from the refrigerant pipe 13 </ b> A through the electromagnetic valve 17 into the receiver dryer unit 14 and the supercooling unit 16. Here, the refrigerant is supercooled.
The refrigerant that has exited the supercooling section 16 of the outdoor heat exchanger 7 enters the refrigerant pipe 13 </ b> B, reaches the indoor expansion valve 8 through 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. The air blown out from the indoor blower 27 by the heat absorption action at this time is cooled. In addition, since 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 reaches the accumulator 12 through the refrigerant pipe 13C through the internal heat exchanger 19, and repeats circulation that is sucked into the compressor 2 there through. At this time, since the outdoor expansion valve 6 is fully closed, similarly, it is possible to suppress or prevent the disadvantage that the refrigerant discharged from the compressor 2 flows backward from the outdoor expansion valve 6 into the radiator 4. . Thereby, the fall of a refrigerant | coolant circulation amount can be suppressed or eliminated and air-conditioning capability can be ensured now.
Here, since the high-temperature refrigerant flows through the radiator 4 in the cooling mode described above, direct heat conduction from the radiator 4 to the HVAC unit 10 occurs not a little, but in this MAX cooling mode, the refrigerant flows into the radiator 4. Therefore, the air in the air flow passage 3 from the heat absorber 9 is not heated by the heat transmitted from the radiator 4 to the HVAC unit 10. Therefore, powerful cooling of the passenger compartment is performed, and particularly in an environment where the outside air temperature Tam is high, the passenger compartment can be quickly cooled to realize comfortable air conditioning in the passenger compartment. Also in this MAX cooling mode, the heat pump controller 32 is also connected to the 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 the target value. 2 is controlled.
(6) Auxiliary heater single mode
Note that the control device 11 of the embodiment stops the compressor 2 and the outdoor blower 15 of the refrigerant circuit R and energizes the auxiliary heater 23 when, for example, excessive frost formation occurs in the outdoor heat exchanger 7. The auxiliary heater single mode for heating the passenger compartment with only 23 is provided. Also in this case, the heat pump controller 32 controls 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.
The air conditioning controller 20 operates the indoor blower 27, and the air mix damper 28 passes the air in the air flow passage 3 blown out from the indoor blower 27 to the auxiliary heater 23 of the heat exchange passage 3A for heating, and the air volume is reduced. The state to be adjusted. Since the air heated by the auxiliary heater 23 is blown into the vehicle interior from each of the air outlets 29A to 29C, the vehicle interior is thereby heated.
(7) Switching operation mode
The air conditioning controller 20 calculates the target blowing 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 passenger compartment.
TAO = (Tset−Tin) × K + Tbal (f (Tset, SUN, Tam))
.. (I)
Here, Tset is a set temperature in the passenger compartment set by the air conditioning operation unit 53, Tin is a room temperature detected by the inside air temperature sensor 37, K is a coefficient, Tbal is a set temperature Tset, and a solar radiation amount detected by the solar radiation sensor 51. SUN is a balance value calculated from the outside air temperature Tam detected by the outside air temperature sensor 33. And generally this target blowing temperature TAO is so high that the outside temperature Tam is low, and it falls as the outside temperature Tam rises.
When the heat pump controller 32 is activated, the heat pump controller 32 determines which one 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 and the target outlet 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. In addition, after startup, the outside air temperature Tam, the humidity in the passenger compartment, the target blowing 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 sink temperature Te, By switching each operation mode based on parameters such as the target heat absorber temperature TEO and whether or not there is a dehumidification request in the passenger compartment, the heating mode, dehumidification heating mode, and dehumidification are accurately performed according to the environmental conditions and necessity of dehumidification. The cooling mode, the cooling mode, the MAX cooling mode, and the auxiliary heater single mode are switched to control the temperature of the air blown into the vehicle interior to the target blowing temperature TAO, thereby realizing comfortable and efficient vehicle interior air conditioning.
(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 rotational speed (compressor target rotational speed) TGNCh of the compressor 2 for heating mode. The F / F (feed forward) manipulated variable calculation unit 58 of the heat pump controller 32 has an outside air temperature Tam obtained from the outside air temperature sensor 33, a blower voltage BLV of the indoor blower 27, and SW = (TAO−Te) / (TH−Te). ) Obtained by the air mix damper 28, the target supercooling degree TGSC that is the target value of the supercooling degree SC at the outlet of the radiator 4, and the target heater that is the target value of the temperature of the radiator 4 described above. Based on the temperature TCO (transmitted from the air conditioning controller 20) and the target radiator pressure PCO that is the target value of the pressure of the radiator 4, the F / F manipulated variable TGNChff of the compressor target rotational speed is calculated.
Here, the above-mentioned TH for calculating the air volume ratio SW is the temperature of the leeward air of the radiator 4 (hereinafter referred to as the heating temperature), and the heat pump controller 32 calculates the first-order lag calculation formula (II) shown below. presume.
TH = (INTL × TH0 + Tau × THz) / (Tau + INTL) (II)
Here, INTL is the calculation cycle (constant), Tau is the time constant of the primary delay, TH0 is the steady value of the heating temperature TH in the steady state before the primary delay calculation, and THz is the previous value of the heating temperature TH. By estimating the heating temperature TH in this way, there is no need to provide a special temperature sensor.
The heat pump controller 32 changes the time constant Tau and the steady value TH0 according to the operation mode described above, thereby making the above-described estimation formula (II) different depending on the operation mode, and estimates the heating temperature TH. The 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 calculator 59 based on the target subcooling degree TGSC and the target heater temperature TCO. Further, the F / B (feedback) manipulated variable calculator 60 calculates the F / B manipulated variable TGNChfb of the compressor target rotational speed based on the target radiator pressure PCO and the radiator pressure PCI that is the refrigerant pressure of the radiator 4. To do. The F / F manipulated variable TGNCnff computed by the F / F manipulated variable computing unit 58 and the TGNChfb computed by the F / B manipulated variable computing unit 60 are added by the adder 61, and the control upper limit value and the control are controlled by the limit setting unit 62. After the lower limit is set, it is determined as the compressor target rotational speed TGNCh. In the heating mode, the heat pump controller 32 controls the rotational speed NC of the compressor 2 based on the compressor target rotational speed TGNCh.
(9) Control of the compressor 2 and the auxiliary heater 23 in the dehumidifying heating mode by the heat pump controller 32
On the other hand, FIG. 5 is a control block diagram of the heat pump controller 32 that determines the target rotational speed (compressor target rotational speed) TGNCc of the compressor 2 for the dehumidifying and heating mode. The F / F manipulated variable calculation unit 63 of the heat pump controller 32 is a target heat release that is a target value of the outside air temperature Tam, the volumetric air volume Ga of the air flowing into the air flow passage 3, and the pressure of the radiator 4 (radiator pressure PCI). Based on the compressor 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), the F / F manipulated variable TGNCcff of the compressor target rotational speed is calculated.
Further, the F / B operation amount calculation unit 64 calculates the F / B operation amount TGNCcfb of the compressor target rotational speed based on the target heat absorber temperature TEO (transmitted from the air conditioning controller 20) and the heat absorber temperature Te. Then, the F / F manipulated variable TGNCcff computed by the F / F manipulated variable computing unit 63 and the F / B manipulated variable TGNCcfb computed by the F / B manipulated variable computing unit 64 are added by the adder 66, and the limit setting unit 67 After the control upper limit value and the control lower limit value are set, the compressor target rotational speed TGNCc is determined. In the dehumidifying and heating mode, the heat pump controller 32 controls the rotational speed NC of the compressor 2 based on the compressor target rotational speed TGNCc.
FIG. 6 is a control block diagram of the heat pump controller 32 that determines the auxiliary heater required capacity TGQPTC of the auxiliary heater 23 in the dehumidifying heating mode. The subtractor 73 of the heat pump controller 32 receives the target heater temperature TCO and the auxiliary heater temperature Tptc, and calculates a deviation (TCO−Tptc) between the target heater temperature TCO and the auxiliary heater temperature Tptc. This deviation (TCO-Tptc) is input to the F / B control unit 74. The F / B control unit 74 eliminates the deviation (TCO-Tptc) so that the auxiliary heater temperature Tptc becomes the target heater temperature TCO. The required capacity F / B manipulated variable is calculated.
The auxiliary heater required capability F / B manipulated variable calculated by the F / B control unit 74 is determined as the auxiliary heater required capability 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 energization of the auxiliary heater 23 based on the auxiliary heater required capacity TGQPTC, thereby generating heat (heating) of the auxiliary heater 23 so that the auxiliary heater temperature Tptc becomes the target heater temperature TCO. To control.
Thus, in the dehumidifying heating mode, 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, and controls the heat generation of the auxiliary heater 23 based on the target heater temperature TCO. Thus, cooling and dehumidification by the heat absorber 9 and heating by the auxiliary heater 23 in the dehumidifying heating mode are accurately controlled. As a result, it is possible to control the temperature to a more accurate heating temperature while more appropriately dehumidifying the air blown into the passenger compartment, thereby realizing more comfortable and efficient dehumidifying heating in the passenger compartment. Will be able to.
(10) Control of the air mix damper 28
Next, the 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 volume of the air flowing into the air flow passage 3 described above, Te is the heat absorber temperature, 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 is based on the air volume ratio SW that is passed through the radiator 4 and the auxiliary heater 23 in the heating heat exchange passage 3A calculated by the above-described expression (the following expression (III)) so that the air volume of the ratio is obtained. Further, 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 flow rate ratio SW passing through the radiator 4 and the auxiliary heater 23 in the heat exchange passage 3A for heating changes in a range of 0 ≦ SW ≦ 1, and when “0”, the air is not passed through 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 passed through the bypass passage 3B, and the air mix fully open state in which all the air in the air flow passage 3 is passed through the heating heat exchange passage 3A with "1" It becomes. That is, the air volume to the radiator 4 is Ga × SW.
(11) Defrosting determination of outdoor heat exchanger and compressor stop control based on frosting determination
As described above, in the heating mode, the outdoor heat exchanger 7 absorbs heat from the outside air and becomes a low temperature. Therefore, moisture in the outside air adheres to the outdoor heat exchanger 7 as frost. If this frost growth grows, the heat exchange between the outdoor heat exchanger 7 and the outside air that is vented to it will be significantly impeded, and the operating efficiency of the compressor 2 will be reduced. Moreover, the outdoor blower 15 and the like may be damaged due to excessive frost formation. Therefore, the heat pump controller 32 determines the progress of frost formation on the outdoor heat exchanger 7 as follows.
(11-1) Determination of progress of frost formation on outdoor heat exchanger and compressor stop control (part 1)
Next, an example of determination of the progress of frost formation on the outdoor heat exchanger 7 and stop control of the compressor 2 based on the determination will be described with reference to FIGS. 7 and 8. In this embodiment, the heat pump controller 32 uses the current refrigerant evaporation temperature TXO of the outdoor heat exchanger 7 obtained from the outdoor heat exchanger temperature sensor 54, and the outdoor heat exchanger 7 is not frosted in a low humidity environment. Based on the refrigerant evaporation temperature TXObase of the outdoor heat exchanger 7 at the time of frost formation, the progress state of frost formation on the outdoor heat exchanger 7 is determined.
First, the heat pump controller 32 determines whether or not the vehicle air conditioner 1 (HP) has been determined to be faulty in step S1 of FIG. 7, and if not determined to be faulty, the process proceeds to step S2 where the current frost flag is reset. ("0") is determined. Assuming that the frost flag is currently reset, the heat pump controller 32 proceeds to step S3, and determines whether or not the current operation mode is the heating mode.
If the current operation mode is the heating mode, the process proceeds to step S4, and a difference ΔTXO (ΔTXO = TXObase−TXO) between the refrigerant evaporation temperature TXObase and the current refrigerant evaporation temperature TXO during no frosting is calculated (calculated). To do. In this case, the heat pump controller 32 estimates the refrigerant evaporation temperature TXObase of the outdoor heat exchanger 7 during non-frosting by calculating using the following equation (IV).
TXObase = f (Tam, NC, Ga * SW, VSP, PCI)
= K1 * Tam + k2 * NC + k3 * Ga * SW + k4 * VSP + k5 * PCI
.. (IV)
Here, Tam, which is a parameter of the formula (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 used are the radiator pressure, and k1 to k5 are coefficients, which are obtained beforehand by experiments.
The outside air temperature Tam is an index indicating the intake air temperature (environmental condition) of the outdoor heat exchanger 7. The lower the outside air temperature Tam (the intake air temperature of the outdoor heat exchanger 7), the lower the TXObase. Therefore, the coefficient k1 is a positive value. Similarly, the index indicating the intake air temperature of the outdoor heat exchanger 7 is not limited to the outdoor air temperature Tam.
Further, the rotational speed NC of the compressor 2 is an index indicating the refrigerant flow rate (operating condition) in the refrigerant circuit R, and TXObase tends to decrease as the rotational speed NC increases (the refrigerant flow rate increases). Therefore, the coefficient k2 is a negative value.
Ga * SW is an index indicating the amount of air passing through the radiator 4 (operating condition). The larger the Ga * SW (the larger the amount of air passing through the radiator 4), the lower the TXObase. Therefore, the coefficient k3 is 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 air speed (operation state) of the outdoor heat exchanger 7, and the TXObase tends to be lower as the vehicle speed VSP is lower (lower the passing air speed of the outdoor heat exchanger 7). Therefore, the coefficient k4 is a positive value. The index indicating the passing air speed of the outdoor heat exchanger 7 is not limited to this, and the voltage of the outdoor blower 15 may be used.
The radiator pressure PCI is an index indicating the refrigerant pressure (operating condition) of the radiator 4. The higher the radiator pressure PCI, the lower the TXObase. Accordingly, the coefficient k5 is a negative value.
In addition, although the outside temperature Tam, the rotation speed NC of the compressor 2, the passing air amount Ga * SW of the radiator 4, the vehicle speed VSP, and the radiator pressure PCI are used as parameters of the expression (IV) of this embodiment. The parameters of IV) are not limited to all of the above, and any one of them or a combination thereof may be used.
Then, in step S4, the controller 32 calculates the difference ΔTXO (ΔTXO = ΔTX) between the refrigerant evaporating temperature TXObase and the current refrigerant evaporating temperature TXO at the time of no frosting obtained by substituting the current values of the respective parameters into equation (IV). TXObase-TXO) is calculated. Next, the heat pump controller 32 determines whether or not a predetermined time has elapsed after the activation of the heating mode in step S5. If the predetermined time has not elapsed since the start of the heating mode, the process proceeds to step S11 and the compressor 2 is operated. Continue (HP operation). That is, the compressor 2 is not stopped based on the determination of the progress of frost formation on the outdoor heat exchanger 7 described later.
When the predetermined time has elapsed since the activation of the heating mode in step S5, the heat pump controller 32 proceeds to step S6, where the refrigerant evaporation temperature TXO is lower than the refrigerant evaporation temperature TXObase when there is no frost, and the difference ΔTXO is the first. It is determined whether or not the state where the threshold value A1 is larger than the first threshold value A1 (for example, 15 deg) continues for the first predetermined time t1 (for example, 30 seconds). When the predetermined time t1 is continued, it is determined that excessive frost formation has progressed in the outdoor heat exchanger 7 in a short time.
In FIG. 8, the solid line indicates the change in the refrigerant evaporation temperature TXO of the outdoor heat exchanger 7, and the broken line indicates the change in the refrigerant evaporation temperature TXObase when there is no frost formation. In the initial stage of startup (non-frosting), the refrigerant evaporation temperature TXO of the outdoor heat exchanger 7 and the refrigerant evaporation temperature TXObase at the time of no frosting are substantially the same value. As the heating mode progresses, the temperature in the passenger compartment is warmed and the load on the vehicle air conditioner 1 is reduced. Therefore, the refrigerant flow rate and the amount of air passing through the radiator 4 are also reduced. The calculated TXObase (broken line in FIG. 8) rises.
On the other hand, when frost formation occurs in the outdoor heat exchanger 7, the heat exchange performance with the outside air is hindered, so the refrigerant evaporation temperature TXO (solid line) decreases and eventually falls below the TXObase. When the refrigerant evaporation temperature TXO further decreases and the difference ΔTXO (TXObase−TXO) becomes larger than the first threshold value A1, and the state continues for the first predetermined time t1, the heat pump controller 32 performs step S6. Thus, it is determined that excessive frost formation has progressed in the outdoor heat exchanger 7 in a short time, and the process proceeds to step S7.
On the other hand, if excessive frost formation does not proceed in a short time in step S6, the heat pump controller 32 proceeds to step S10, and this time the difference ΔTXO is smaller than the first threshold A1 and the second threshold A2 (for example, 5 deg, etc.). ) It is determined whether or not the state of being greater than the first predetermined time t1 has continued for a second predetermined time t2 (for example, 60 minutes), and the state in which ΔTXO is greater than the second threshold A2 When the predetermined time t2 of 2 is continued, it is determined that moderate frosting has continued in the outdoor heat exchanger 7 for a long time, and the process proceeds to step S7. If it is determined in step S10 that moderate frosting has not continued in the outdoor heat exchanger 7 for a long time, the heat pump controller 32 proceeds to step S11 and continues the operation of the compressor 2.
In step S7, the heat pump controller 32 determines whether the heating temperature TH, which is the temperature of the air downstream of the radiator 4, is lower than the target heater temperature TCO-α (α is a relatively small differential), which is the target value of the temperature of the radiator 4. Judge whether or not. As described above, the target heater temperature TCO calculated from the target outlet temperature TAO is the required capacity of the radiator 4. The heating temperature TH indicates the current heating capacity of the radiator 4. Therefore, when TH ≧ TCO−α (that is, TCO−TH ≦ α), the heating capacity of the radiator 4 satisfies the required capacity. And in the situation where the heating capacity of the radiator 4 satisfies the required capacity (No in step S7), the heat pump controller 32 proceeds to step S11 and continues the operation of the compressor 2.
On the other hand, if the heating temperature TH is lower than the target heater temperature TCO in step S7 and the difference is larger than α (Yes: the heating capacity of the radiator 4 does not satisfy the required capacity), the heat pump controller 32 proceeds to step S8. Proceed and stop the compressor 2 (HP operation not permitted). And it progresses to step S9 and sets a frosting flag ("1"). Thereafter, the process proceeds from step S2 to step S8, and the heat pump controller 32 prohibits starting of the compressor 2 until the frosting flag is reset.
Further, when the compressor 2 is stopped in step S8, the heat pump controller 32 switches the operation mode to the above-described auxiliary heater single mode and heats the vehicle interior by the auxiliary heater 23. In addition, by stopping the compressor 2, the frost formation of the outdoor heat exchanger 7 is melted, and defrosting is performed. In particular, since the defrosting proceeds rapidly while the vehicle is stopped, the heat pump controller 32 determines that the defrosting of the outdoor heat exchanger 7 has been completed, for example, when a predetermined period has elapsed since the compressor 2 was stopped. Then, the frosting flag described above is reset. As a result, the prohibition of starting the compressor 2 based on the determination of the progress of frost formation on the outdoor heat exchanger 7 is released, and the operation mode is switched from the auxiliary heater single mode to the heating mode.
(11-2) Determination of progress of frost formation on outdoor heat exchanger and compressor stop control (part 2)
Next, another example of the determination of the progress of frosting in the outdoor heat exchanger 7 and the stop control of the compressor will be described with reference to FIG. In this example, the heat pump controller 32 performs the same control as in FIG. 7, but the difference ΔTXO in FIG. 7 is replaced with a difference ΔPXO described later. In this embodiment, the heat pump controller 32 is obtained from the outdoor heat exchanger pressure sensor 56.
Based on the current refrigerant evaporation pressure PXO of the outdoor heat exchanger 7 and the refrigerant evaporation pressure PXObase of the outdoor heat exchanger 7 when the outside air is not frosted in the low humidity environment and is not frosted, The progress state of frost formation on the outdoor heat exchanger 7 is determined. In this case, the heat pump controller 32 estimates the refrigerant evaporation pressure PXObase of the outdoor heat exchanger 7 during non-frosting by calculating using the following equation (V).
PXObase = f (Tam, NC, Ga * SW, VSP, PCI)
= K6 * Tam + k7 * NC + k8 * Ga * SW + k9 * VSP + k10 * PCI
.. (V)
In addition, since each parameter of Formula (V) is the same as that of Formula (IV), description is abbreviate | omitted. Also, the coefficients k6 to k10 have the same tendency (positive / negative) as the coefficients k1 to k5 described above.
In FIG. 9, the solid line indicates the change in the refrigerant evaporation pressure PXO of the outdoor heat exchanger 7, and the broken line indicates the change in the refrigerant evaporation pressure PXObase when there is no frost formation. In the initial stage of startup (non-frosting), the refrigerant evaporation pressure PXO of the outdoor heat exchanger 7 and the refrigerant evaporation pressure PXObase at the time of no frosting are substantially the same value. As the heating mode progresses, the temperature in the passenger compartment is warmed and the load on the vehicle air conditioner 1 is reduced. Therefore, the refrigerant flow rate and the amount of air passing through the radiator 4 are also reduced. The calculated PXObase (broken line in FIG. 9) rises.
On the other hand, when frost formation occurs in the outdoor heat exchanger 7, the heat exchange performance with the outside air is hindered, so the refrigerant evaporation pressure PXO (solid line) decreases and eventually falls below PXObase. In this embodiment, the heat pump controller 32 substitutes the current value of each parameter for the equation (V) in step S4 of FIG. 7 and the refrigerant evaporation pressure PXObase at the time of no frost formation and the current refrigerant evaporation. A difference ΔPXO (ΔPXO = PXObase−PXO) from the pressure PXO is calculated (calculated). Thereafter, the control is performed by replacing the difference ΔTXO in step S6 and step S10 in FIG. 7 with the difference ΔPXO. However, the first threshold value A1 and the second threshold value A2 are different from the case of the difference ΔTXO.
As described above, the heat pump controller 32 determines the progress of frost formation on the outdoor heat exchanger 7 based on the difference ΔTXO or the difference ΔPXO, and the state in which the frost formation on the outdoor heat exchanger 7 has progressed. If the compressor 2 is stopped when it continues for a predetermined time, the compressor 2 can be stopped in a state where frost formation on the outdoor heat exchanger 7 has progressed. Thereby, it is possible to prevent the operation of the compressor 2 from being continued in a situation where the operation efficiency is reduced due to the frost formation of the outdoor heat exchanger 7 and contribute to energy saving, and the outdoor heat exchanger. Thus, it is possible to solve the problem of equipment reliability reduction and defrosting due to the excessive frost of 7.
In this case, the heat pump controller 32 determines the refrigerant evaporation temperature TXObase of the outdoor heat exchanger 7 when there is no frosting and the refrigerant evaporation pressure PXObase of the outdoor heat exchanger 7 when there is no frosting based on an index indicating environmental conditions and operating conditions. Since it estimates, the progress of frost formation of the outdoor heat exchanger 7 can be accurately detected. Further, the heat pump controller 32 stops the compressor 2 when the difference ΔTXO or the difference ΔPXO is larger than the first threshold value A1 for the first predetermined time t1, so that the excessive amount of the outdoor heat exchanger 7 is excessive. When the frost formation proceeds in a relatively short time, the compressor 2 can be quickly stopped.
On the other hand, when the difference ΔTXO or the difference ΔPXO is larger than the second threshold A2 smaller than the first threshold A1, the heat pump controller 32 continues for a second predetermined time t2 longer than the first predetermined time t1. Since the compressor 2 is also stopped, the compressor 2 can be reliably stopped even when moderate frost formation of the outdoor heat exchanger 7 continues for a relatively long time.
However, since the heat pump controller 32 does not stop the compressor 2 based on the determination of the progress of frost formation on the outdoor heat exchanger 7 when the heating capacity of the radiator 4 satisfies the required capacity, the radiator In the situation where the heating capability by 4 is achieved, the stop of the compressor 2 is prohibited, and the comfortable heating in the passenger compartment can be continued as it is.
Moreover, since the heat pump controller 32 does not stop the compressor 2 based on the determination of the progress state of frost formation on the outdoor heat exchanger 7 until a predetermined time has elapsed after activation, the unstable operation state immediately after activation. This makes it possible to eliminate misjudgment.
Furthermore, the heat pump controller 32 starts the compressor 2 until the outdoor heat exchanger 7 is defrosted after stopping the compressor 2 based on the determination of the progress of frost formation on the outdoor heat exchanger 7. Since the prohibition is prohibited, the restart of the compressor 2 in a state where the frost is left in the outdoor heat exchanger 7 is prohibited, so that it is possible to avoid inconvenience that frost that is hard to melt is generated. become.
Furthermore, when the compressor 2 is stopped based on the determination of the progress of frost formation on the outdoor heat exchanger 7, the heat pump controller 32 heats the vehicle interior by the auxiliary heater 23 in the auxiliary heater single mode. Even when the compressor 2 is stopped due to a decrease in the operation efficiency of No. 2, the passenger compartment can be heated by the auxiliary heater 23 to reduce the passenger's discomfort.

(12) Compressor Stop Control Based on Suction Refrigerant Temperature Ts and Suction Refrigerant Pressure Ps Next, the reduction in operating efficiency of the compressor 2 will be eliminated based on the suction refrigerant temperature Ts and suction refrigerant pressure Ps of the compressor 2. One control will be described. When the outside air temperature Tam is lowered, the suction refrigerant temperature Ts and the suction refrigerant pressure Ps of the compressor 2 are lowered. Therefore, in this state, the rotational speed NC of the compressor 2 cannot be increased, and the operation efficiency is lowered. Therefore, the heat pump controller 32 stops the compressor 2 as follows based on the suction refrigerant temperature Ts of the compressor 2 detected by the suction temperature sensor 55 and the suction refrigerant pressure Ps of the compressor 2 detected by the suction pressure sensor 44. Execute control to
Next, an example of the stop control of the compressor 2 based on the suction refrigerant temperature Ts and the suction refrigerant pressure Ps will be described with reference to FIGS. 10 and 11. In this embodiment, the heat pump controller 32 first determines whether or not the vehicle air conditioner 1 (HP) has not been determined to be faulty in step S13 of FIG. 10, and if not determined to be faulty, the heat pump controller 32 is step S14. It progresses to and it is judged whether the present operation mode is heating mode.
And when the present operation mode is heating mode, it progresses to Step S15, and it is judged whether it is immediately after the compressor 2 stopped by protection control mentioned below based on suction refrigerant temperature Ts and suction refrigerant pressure Ps. If it is not immediately after that, the heat pump controller 32 proceeds to step S16 to determine whether the suction refrigerant temperature Ts has become lower than a predetermined first predetermined value Ts1, or whether the suction refrigerant pressure Ps has a predetermined first predetermined value. It is determined whether or not the value is lower than the value Ps1. Here, when Ts ≧ Ts1 and Ps ≧ Ps1, the process proceeds to step S22 and the operation of the compressor 2 (HP operation) is continued.
On the other hand, when the suction refrigerant temperature Ts becomes lower than the first predetermined value Ts1 due to a decrease in the outside air temperature or the like, or when the suction refrigerant pressure Ps becomes lower than the first predetermined value Ps1, the heat pump controller 32 performs a step. Proceeding from S16 to step S17, restriction control of the rotational speed NC of the compressor 2 based on the suction refrigerant temperature Ts and the suction refrigerant pressure Ps is executed. In this limit control, the heat pump controller 32 performs control to decelerate the rotational speed NC of the compressor 2 by predetermined steps. Therefore, every time the process returns to step S16, the rotational speed NC of the compressor 2 decreases by a predetermined step.
Next, the heat pump controller 32 proceeds to step S18 to determine whether or not a predetermined time has elapsed after the activation of the heating mode. If the predetermined time has not elapsed since the start of the heating mode, the process proceeds to step S22 and the compressor 2 Continue the operation (HP operation). If the predetermined time has elapsed since the activation of the heating mode in step S18, the heat pump controller 32 proceeds to step S19, is in the above-described limit control state of the rotational speed NC of the compressor 2, and the compressor 2 It is determined whether or not the state in which the rotational speed NC is lower than a predetermined value NC1 (a predetermined value higher than the lowest control rotational speed (for example, 800 rpm)) continues for a predetermined time.
At this time, if the state where the rotational speed NC of the compressor 2 is lower than the predetermined value NC1 does not continue for a predetermined time, the heat pump controller 32 proceeds to step S22 and operates the compressor 2 (HP operation). continue. On the other hand, when the rotational speed NC of the compressor 2 is in the limit control state and the state where the rotational speed NC of the compressor 2 is lower than the predetermined value NC1 continues for a predetermined time, the heat pump controller 32 performs step S19. Advances to step S20 to stop the compressor 2 (HP operation not permitted). Further, when the compressor 2 is stopped in step S20, the heat pump controller 32 switches the operation mode to the auxiliary heater single mode described above, and heats the vehicle interior by the auxiliary heater 23.
This state is shown in FIG. 11 taking the suction refrigerant temperature Ts as an example. After the outside air temperature Tam is lowered by the normal control and the suction refrigerant temperature Ts becomes lower than the first predetermined value Ts1 (for example, −22 ° C., etc.), the restriction control of the rotational speed NC of the compressor 2 is started and the compression is started. The rotational speed NC of the machine 2 decreases (during Ts restriction control). Further, the suction refrigerant temperature Ts changes in a low state by the restriction control. Thereafter, when the rotation speed of the compressor 2 falls below the predetermined value NC1, and the state continues for a predetermined time, the compressor 2 is stopped (during Ts protection control).
Here, what is indicated by a broken line in FIG. 11 is protection control of the conventional compressor 2. Conventionally, since the compressor 2 is stopped when the suction refrigerant temperature Ts reaches a protection stop value Ts3 that is lower than the first predetermined value Ts1, it is longer than in the case of the stop control of the present invention indicated by the solid line. Although the compressor 2 was operated at a low rotational speed NC over time, according to the stop control of the embodiment of the present invention, the compressor 2 can be stopped at an earlier stage, and operation in a situation where the operation efficiency is poor can be avoided. It became so.
Immediately after the compressor 2 is stopped by the protection control based on the suction refrigerant temperature Ts and the suction refrigerant pressure Ps, the heat pump controller 32 proceeds from step S15 to step S21. In this step S21, the heat pump controller 32 now has the suction refrigerant temperature Ts higher than the second predetermined value Ts2 higher than the first predetermined value Ts1 described above, or the suction refrigerant pressure Ps is the first predetermined value described above. It is determined whether or not it has become higher than a second predetermined value Ps2 that is higher than the value Ps1, or whether the outside air temperature Tam detected by the outside air temperature sensor 33 has become higher than a predetermined value (for example, −15 ° C.). Here, if Ts <Ts2, Ps <Ps2, and Tam <predetermined value (−15 ° C.), the heat pump controller 32 proceeds to step S20 and prohibits the compressor 2 from starting. The refrigerant suction temperature Ts and the refrigerant suction pressure Ps rise as the outside air temperature Tam rises, and the suction refrigerant temperature Ts becomes higher than a second predetermined value Ts2, or the suction refrigerant pressure Ps is a second predetermined value. When it becomes higher than the value Ps2 or when the outside air temperature Tam becomes higher than a predetermined value, the heat pump controller 32 proceeds from step S21 to step S22, and the compressor 2 is operated. In the example of FIG. 11, the start prohibition of the compressor 2 is released (returned to normal control) when it becomes higher than a second predetermined value Ts2 (for example, −19 ° C. or the like). That is, the prohibition of starting the compressor 2 based on the determination of the refrigerant suction temperature Ts and the refrigerant suction pressure Ps is released, and the operation mode is switched from the auxiliary heater single mode to the heating mode.
When the suction refrigerant temperature Ts of the compressor 2 becomes lower than the first predetermined value Ts1 as in this embodiment, or when the suction refrigerant pressure Ps of the compressor 2 becomes lower than the first predetermined value Ps1, When the heat pump controller 32 executes the limit control for decelerating the rotational speed NC of the compressor 2 and the state in which the rotational speed NC of the compressor 2 is lower than the predetermined value NC1 continues in this limited control state for a predetermined time, If the compressor 2 is stopped, the compressor 2 can be stopped in a state where the suction refrigerant temperature Ts and the suction refrigerant pressure Ps of the compressor 2 are lowered due to a decrease in the outside air temperature Tam or the like.
As a result, it is possible to prevent the operation of the compressor 2 from continuing in a situation where the suction refrigerant temperature Ts and the suction refrigerant pressure Ps are low and the operation efficiency is lowered, thereby contributing to energy saving. It is possible to solve the problem of reliability degradation.
At this time, when the suction refrigerant temperature Ts of the compressor 2 becomes lower than the first predetermined value Ts1 or when the suction refrigerant pressure Ps of the compressor 2 becomes lower than the first predetermined value Ps1. Since the restriction control for reducing the rotational speed NC of the compressor 2 is executed, it is avoided as much as possible that the compressor 2 is stopped due to a decrease in the suction refrigerant temperature Ts and the suction refrigerant pressure Ps, or until the stop. The time can be extended, and the comfortable heating of the passenger compartment can be continued as much as possible.
Further, the heat pump controller 32 does not stop the compressor 2 in the restriction control state based on the suction refrigerant temperature Ts or the suction refrigerant pressure Ps of the compressor 2 until a predetermined time has elapsed after the activation of the heating mode. Thus, an erroneous stop of the compressor 2 in an unstable operation state immediately after startup can be eliminated.
Further, the heat pump controller 32 stops the compressor 2 based on the determination of the suction refrigerant temperature Ts of the compressor 2 or the suction refrigerant pressure Ps, and then the suction refrigerant temperature Ts of the compressor 2 is a second predetermined value. Start of the compressor 2 is prohibited until it becomes higher than Ts2, or until the suction refrigerant pressure Ps of the compressor 2 becomes higher than the second predetermined value Ps2, or until the outside air temperature Tam becomes higher than the predetermined value. Therefore, in a situation where the outside air temperature Tam is low and the control is expected to cause the rotational speed NC of the compressor 2 to be lower than the predetermined value NC1, the start-up of the compressor 2 is not permitted and the compressor 2 is frequently stopped / The inconvenience of being activated can be avoided.
Also in this case, when the compressor 2 is stopped based on the determination of the suction refrigerant temperature Ts or the suction refrigerant pressure Ps of the compressor 2, the heat pump controller 32 heats the vehicle interior by the auxiliary heater 23. Even when the compressor is stopped due to a decrease in the operation efficiency of the machine 2, the passenger compartment can be heated by the auxiliary heater 23 to reduce the discomfort of the passenger.

Next, FIG. 12 shows a configuration diagram of a vehicle air conditioner 1 of another embodiment to which the present invention is applied. In this figure, the same reference numerals as those in FIG. 1 indicate the same or similar functions. In the case of this embodiment, the outlet of the supercooling section 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.
The refrigerant pipe 13E on the outlet side of the radiator 4 is branched before the outdoor expansion valve 6, and the branched refrigerant pipe (hereinafter referred to as second bypass pipe) 13F is an electromagnetic valve 22 (for dehumidification). Is connected to the refrigerant pipe 13B downstream of the check valve 18. Further, an evaporating pressure adjusting valve 70 is connected to the refrigerant pipe 13C on the outlet side of the heat absorber 9 on the refrigerant downstream side of the internal heat exchanger 19 and upstream of the refrigerant with respect to the refrigerant pipe 13D. . The electromagnetic valve 22 and the evaporation pressure adjusting valve 70 are also connected to the output of the heat pump controller 32. Note that the bypass device 45 including the bypass pipe 35, the electromagnetic valve 30, and the electromagnetic valve 40 in FIG. 1 of the above-described embodiment is not provided. Others are the same as in FIG.
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 between the heating mode, the dehumidifying heating mode, the internal cycle mode, the dehumidifying cooling mode, the cooling mode, and the auxiliary heater single mode (the MAX cooling mode is present in this embodiment). do not do). The operation when the heating mode, the dehumidifying and cooling mode, and the cooling mode are selected, the refrigerant flow, and the auxiliary heater single mode are the same as those in the above-described embodiment (embodiment 1), and thus the description thereof is omitted. However, in this embodiment (Example 3), the solenoid valve 22 is closed in these heating mode, dehumidifying cooling mode, and cooling mode.
(13) Dehumidifying and heating mode of the vehicle air conditioner 1 of FIG. 12 On the other hand, when the dehumidifying and heating mode is selected, in this embodiment, the heat pump controller 32 opens the electromagnetic valve 21 (for heating) and the electromagnetic valve 17 ( Close for cooling. Further, the electromagnetic valve 22 (for dehumidification) is opened. Then, the compressor 2 is operated. The air conditioning controller 20 operates each of the blowers 15 and 27, and the air mix damper 28 basically heats all the air in the air flow passage 3 that is blown out from the indoor blower 27 and passes through the heat absorber 9 to the heat exchange passage 3A for heating. The auxiliary heater 23 and the radiator 4 are ventilated, but the air volume is also adjusted.
Thereby, 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 path 3 that has flowed into the heat exchange path 3A for heating is passed through the heat radiator 4, the air in the air flow path 3 is heated by the high-temperature refrigerant in the heat radiator 4, while the heat radiator The refrigerant in 4 is deprived of heat by the air and cooled to condense.
The refrigerant liquefied in the radiator 4 exits the radiator 4 and then reaches the outdoor expansion valve 6 through the refrigerant pipe 13E. The refrigerant flowing into the outdoor expansion valve 6 is decompressed there and then flows into the outdoor heat exchanger 7. The refrigerant flowing into the outdoor heat exchanger 7 evaporates, and pumps up heat from the outside air that is ventilated by traveling or by the outdoor blower 15. That is, the refrigerant circuit R becomes a heat pump. Then, the low-temperature refrigerant exiting the outdoor heat exchanger 7 enters the accumulator 12 through the refrigerant pipe 13C through the refrigerant pipe 13A, the solenoid valve 21 and the refrigerant pipe 13D, and is gas-liquid separated there. Repeated circulation inhaled.
Further, a part of the condensed refrigerant flowing through the refrigerant pipe 13E through the radiator 4 is diverted, passes through the electromagnetic valve 22, and reaches the indoor expansion valve 8 through the internal heat exchanger 19 from the second bypass pipe 13F and the refrigerant pipe 13B. It becomes like this. After the refrigerant is depressurized by the indoor expansion valve 8, it flows into the heat absorber 9 and evaporates. Since the moisture in the air blown out from the indoor blower 27 by the heat absorption action at this time condenses and adheres to the heat absorber 9, the air is cooled and dehumidified.
The refrigerant evaporated in the heat absorber 9 sequentially passes through the internal heat exchanger 19 and the evaporation pressure adjusting valve 70 and then merges with the refrigerant from the refrigerant pipe 13D in the refrigerant pipe 13C. Then, the refrigerant is sucked into the compressor 2 through the accumulator 12. repeat. Since the air dehumidified by the heat absorber 9 is reheated in the process of passing through the radiator 4, dehumidifying heating in the passenger compartment is thereby performed.
The air conditioning controller 20 transmits the target heater temperature TCO (target value of the radiator outlet temperature TCI) calculated from the target blowing temperature TAO to the heat pump controller 32. The heat pump controller 32 calculates a target radiator pressure PCO (target value of the radiator pressure PCI) from the target heater temperature TCO, and the refrigerant of the radiator 4 detected by the target radiator pressure PCO and the radiator pressure sensor 47. The number of revolutions NC of the compressor 2 is controlled based on the pressure (radiator pressure PCI, high pressure of the refrigerant circuit R), and heating by the radiator 4 is controlled. 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. In addition, the heat pump controller 32 opens (enlarges the flow path) / closes (flows a small amount of refrigerant) the heat absorber 9 based on the temperature Te of the heat absorber 9 detected by the heat absorber temperature sensor 48. The inconvenience of freezing due to too low temperature is prevented.
(14) Internal cycle mode of the vehicle air conditioner 1 of FIG. 12 In the internal cycle mode, the heat pump controller 32 fully closes the outdoor expansion valve 6 in the dehumidifying and heating mode state (fully closed position), The solenoid valve 21 is closed. Since the outdoor expansion valve 6 and the electromagnetic valve 21 are closed, the inflow of refrigerant to the outdoor heat exchanger 7 and the outflow of refrigerant from the outdoor heat exchanger 7 are blocked. The condensed refrigerant flowing through the refrigerant pipe 13E through the refrigerant flows through the electromagnetic valve 22 to the second bypass pipe 13F. The refrigerant flowing through the second bypass pipe 13F reaches the indoor expansion valve 8 via the internal heat exchanger 19 from the refrigerant pipe 13B. After the refrigerant is depressurized by the indoor expansion valve 8, it flows into the heat absorber 9 and evaporates. Since the moisture in the air blown out from the indoor blower 27 by the heat absorption action at this time condenses and adheres to the heat absorber 9, the air is cooled and dehumidified.
The refrigerant evaporated in the heat absorber 9 sequentially flows through the refrigerant pipe 13C through the internal heat exchanger 19 and the evaporation pressure adjustment valve 70, and repeats circulation that is sucked into the compressor 2 through the accumulator 12. Since the air dehumidified by the heat absorber 9 is reheated in the process of passing through the radiator 4, dehumidifying heating in the passenger compartment is thereby performed. Since the refrigerant is circulated between the radiator 4 (radiation) and the heat absorber 9 (heat absorption) in the passage 3, heat from the outside air is not pumped up, and heating for the consumed power of the compressor 2 is performed. Ability is demonstrated. Since the entire amount of the refrigerant flows through the heat absorber 9 that exhibits the dehumidifying action, the dehumidifying capacity is higher than that in the dehumidifying and heating mode, but the heating capacity is lowered.
The air conditioning controller 20 transmits the target heater temperature TCO (target value of the 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 rotational speed NC of the compressor 2 is controlled based on the refrigerant pressure (radiator pressure PCI, high pressure of the refrigerant circuit R), and heating by the radiator 4 is controlled.
And also in the case of this Example, it operates by frost formation of the outdoor heat exchanger 7 by performing the frost determination of the outdoor heat exchanger of (11) mentioned above and the stop control of the compressor based on the frost determination. It is possible to prevent the operation of the compressor 2 from being continued in a situation where the efficiency is reduced, and to contribute to energy saving, and to reduce the reliability of the equipment due to excessive frost formation of the outdoor heat exchanger 7 The problem of defrosting can be solved. Further, by performing the stop control of the compressor based on the suction refrigerant temperature Ts and the suction refrigerant pressure Ps of (12) described above, the suction refrigerant temperature Ts and the suction refrigerant pressure Ps are lowered due to a decrease in the outside air temperature and the operation efficiency is lowered. In such a situation, the operation of the compressor 2 can be prevented from being continued, which can contribute to energy saving, and can also solve the problem of reduced device reliability.
It should be noted that the numerical values shown in the embodiments are not limited thereto, and should be appropriately set according to the apparatus to be applied. Further, the auxiliary heating device is not limited to the auxiliary heater 23 shown in the embodiment, and a heat medium circulation circuit that heats the air in the air flow passage 3 by circulating the heat medium heated by the heater or an engine. You may utilize the heater core etc. which circulate through the heated radiator water.

DESCRIPTION OF SYMBOLS 1 Vehicle air conditioner 2 Compressor 3 Air flow path 4 Radiator 6 Outdoor expansion valve 7 Outdoor heat exchanger 8 Indoor expansion valve 9 Heat absorber 10 HVAC unit 11 Controller 20 Air conditioning controller 23 Auxiliary heater (auxiliary heating device)
27 Indoor blower
28 Air Mix Damper 32 Heat Pump Controller 33 Outside Air Temperature Sensor 44 Suction Pressure Sensor 55 Suction Temperature Sensor 65 Vehicle Communication Bus R Refrigerant Circuit

Claims (11)

1. A compressor for compressing the refrigerant;
   An air flow passage through which air to be supplied into the passenger compartment flows;
   A radiator for radiating the refrigerant to heat the air supplied from the air flow passage to the vehicle interior;
   An outdoor heat exchanger provided outside the passenger compartment to absorb heat from the refrigerant;
   A control device,
   Vehicle air that heats at least the refrigerant discharged from the compressor by the control device and radiates heat by the radiator, depressurizes the radiated refrigerant, and then absorbs heat by the outdoor heat exchanger. In the harmony device,
   The control device includes the refrigerant evaporation temperature TXO of the outdoor heat exchanger and the non-adherence when the refrigerant evaporation temperature TXO of the outdoor heat exchanger is lower than the refrigerant evaporation temperature TXObase of the outdoor heat exchanger when no frost is formed. Based on the difference ΔTXO = TXObase−TXO from the refrigerant evaporation temperature TXObase of the outdoor heat exchanger during frost, or the refrigerant evaporation pressure of the outdoor heat exchanger when the refrigerant evaporation pressure PXO of the outdoor heat exchanger is not frosted Based on the difference ΔPXO = PXObase−PXO between the refrigerant evaporating pressure PXO of the outdoor heat exchanger when lower than PXObase and the refrigerant evaporating pressure PXObase of the outdoor heat exchanger at the time of no frost formation, While judging the progress of frost formation,
   The vehicle air conditioner is characterized in that the compressor is stopped when frosting on the outdoor heat exchanger has continued for a predetermined time.
2. The control device is configured such that the refrigerant evaporating temperature TXObase of the outdoor heat exchanger at the time of no frost formation or the refrigerant of the outdoor heat exchanger at the time of no frost formation based on an index indicating environmental conditions and / or operating conditions The vehicle air conditioner according to claim 1, wherein an evaporation pressure PXObase is estimated.
3. 2. The control device according to claim 1, wherein the controller stops the compressor when the difference ΔTXO or the difference ΔPXO is larger than a first threshold value A <b> 1 continues for a first predetermined time t <b> 1. Item 3. The vehicle air conditioner according to Item 2.
4. In the case where the difference ΔTXO or the difference ΔPXO is greater than a second threshold A2 that is smaller than the first threshold A1 continues for a second predetermined time t2 that is longer than the first predetermined time t1. The vehicle air conditioner according to claim 3, wherein the compressor is stopped.
5. The control device does not stop the compressor based on the determination of the progress of frost formation on the outdoor heat exchanger in a situation where the heating capacity of the radiator satisfies a required capacity. The vehicle air conditioner according to any one of claims 1 to 4.
6. The said control apparatus does not stop the said compressor based on determination of the progress state of the frost formation to the said outdoor heat exchanger until predetermined time passes after starting. The vehicle air conditioner according to any one of the above.
7. The control device prohibits starting of the compressor until the outdoor heat exchanger is defrosted after stopping the compressor based on the determination of the progress of frost formation on the outdoor heat exchanger. The vehicle air conditioner according to any one of claims 1 to 6, wherein the vehicle air conditioner is provided.
8. A compressor for compressing the refrigerant;
   An air flow passage through which air to be supplied into the passenger compartment flows;
   A radiator for radiating the refrigerant to heat the air supplied from the air flow passage to the vehicle interior;
   An outdoor heat exchanger provided outside the passenger compartment to absorb heat from the refrigerant;
   A control device,
   Vehicle air that heats at least the refrigerant discharged from the compressor by the control device and radiates heat by the radiator, depressurizes the radiated refrigerant, and then absorbs heat by the outdoor heat exchanger. In the harmony device,
   When the suction refrigerant temperature Ts of the compressor is lower than a first predetermined value Ts1, or when the suction refrigerant pressure Ps of the compressor is lower than a first predetermined value Ps1, While performing the limiting control to decelerate the rotational speed NC of the compressor,
   In the limit control state, the vehicle air conditioner is characterized in that the compressor is stopped when a state where the rotational speed NC of the compressor is lower than a predetermined value NC1 continues for a predetermined time.
9. The control device does not stop the compressor in the restriction control state based on the suction refrigerant temperature Ts or the suction refrigerant pressure Ps of the compressor until a predetermined time elapses after starting. The vehicle air conditioner according to claim 8.
10. The control device stops the compressor based on the determination of the suction refrigerant temperature Ts or the suction refrigerant pressure Ps of the compressor, and then the suction refrigerant temperature Ts of the compressor is greater than the first predetermined value Ts1. Until the higher second predetermined value Ts2 is reached, or until the suction refrigerant pressure Ps of the compressor becomes higher than a second predetermined value Ps2 higher than the first predetermined value Ps1, or the outside air temperature is a predetermined value. The vehicle air conditioner according to claim 8 or 9, wherein starting of the compressor is prohibited until it becomes higher.
11. An auxiliary heating device provided in the air flow passage,
    The control device determines when the compressor is stopped based on the determination of the progress of frost formation on the outdoor heat exchanger, or when determining the suction refrigerant temperature Ts or the suction refrigerant pressure Ps of the compressor. The vehicle air conditioner according to any one of claims 1 to 10, wherein when the compressor is stopped based on the auxiliary heating device, the vehicle interior is heated by the auxiliary heating device.

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