WO2018123636A1

WO2018123636A1 - Vehicle air-conditioning apparatus

Info

Publication number: WO2018123636A1
Application number: PCT/JP2017/045010
Authority: WO
Inventors: 竜宮腰; 耕平山下
Original assignee: サンデン・オートモーティブクライメイトシステム株式会社
Priority date: 2016-12-27
Filing date: 2017-12-08
Publication date: 2018-07-05
Also published as: JP2018103879A

Abstract

The purpose of the present invention is to enable heating by an auxiliary heating device to be carried out appropriately, even in a vehicle air-conditioning device which performs control to limit rotational speed. Refrigerant discharged from the compressor 2 is made to radiate heat by means of a radiator 4, and after depressurization, is made to absorb heat by means of an outdoor heat exchanger 7, thereby heating the interior of the cabin. The operation of the compressor is limited on the basis of the intake refrigerant temperature Ts of the compressor, and control to limit rotational speed is performed to protect the compressor. The apparatus is equipped with an auxiliary heating apparatus for heating the air that is supplied to the interior of the cabin. A controller takes into account control to limit rotational speed and performs heating by means of an auxiliary heating device to supplement the lack of heating capacity by the radiator.

Description

Air conditioner for vehicles

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

Hybrid vehicles and electric vehicles have come into widespread use due to the emergence of environmental problems in recent years. As an air conditioner that can be applied to such a vehicle, it is provided in a compressor that is supplied with power from a battery of the vehicle and compresses and discharges the refrigerant, and an air flow passage through which air supplied to the passenger compartment flows. The refrigerant discharged from the compressor is provided with a radiator that dissipates the refrigerant, a heat absorber that is provided in the air flow passage to absorb the refrigerant, and an outdoor heat exchanger that is provided outside the vehicle cabin to dissipate or absorb the refrigerant. In the heat sink, the heating mode in which the refrigerant radiated in the radiator absorbs heat in the outdoor heat exchanger, and the refrigerant discharged from the compressor is radiated in the radiator, and the refrigerant radiated in the radiator is radiated in the heat absorber. Each mode of the dehumidifying heating and dehumidifying cooling modes for absorbing heat and the cooling mode for radiating the refrigerant discharged from the compressor in the outdoor heat exchanger and absorbing heat in the heat absorber. Have been developed which perform switching (for example, see Patent Document 1).
Furthermore, in patent document 1, the heat medium-air heat exchanger (auxiliary heating device) of the heat medium circulation circuit is arranged in the air flow passage, and the heating capacity by the radiator is insufficient with respect to the required capacity in the heating mode. The heat medium heated by the electric heater fed from the battery is circulated through the heat medium-air heat exchanger to heat the air supplied into the passenger compartment to compensate for the shortage.
In this case, the maximum heating capacity that the radiator can generate is estimated from the maximum rotation speed NCmax of the compressor, and the required capacity of the auxiliary heating device is calculated from the difference between the required heating capacity and the estimated value of the maximum heating capacity. Thus, auxiliary heating by a heat medium-air heat exchanger was performed.

JP2015-229370A

Here, particularly in an environment where the outside air temperature is low, the pressure of the refrigerant sucked into the compressor is lowered, and the suction refrigerant temperature Ts of the compressor is also lowered. In such a state, since there is a risk of damaging the compressor, the vehicle air conditioner limits the rotation speed of the compressor based on the suction refrigerant temperature Ts, for example, and protects the compressor. Control is performed. In the rotation speed limit control in this case, the compressor rotation speed is generally limited so that the suction refrigerant temperature Ts does not fall below a predetermined limit target value. In that case, the rotation speed of the compressor is set to the maximum rotation. It cannot be increased to several NCmax.
Therefore, as described above, when the required capacity of the auxiliary heating device is obtained from the maximum heating capacity estimated from the maximum rotation number NCmax of the compressor, the heating capacity of the auxiliary heating apparatus is insufficient particularly at the initial stage of startup, and the start-up of the heating is delayed. There was a problem.
The present invention has been made to solve the related art technical problem, and also in a vehicle air conditioner that performs compressor speed limit control so that heating by an auxiliary heating device can be performed appropriately. The purpose is to do.

An air conditioner for a vehicle according to the present invention includes a compressor that compresses a refrigerant, a radiator that radiates the refrigerant and heats the air that is supplied to the vehicle interior, and is provided outside the vehicle compartment to absorb the refrigerant. An outdoor heat exchanger and a control device are provided. The control device dissipates the refrigerant discharged from the compressor with a radiator, depressurizes the dissipated refrigerant, and then absorbs heat with the outdoor heat exchanger. The vehicle interior is heated, and the rotational speed limit control is performed to protect the compressor by limiting the rotational speed of the compressor, and an auxiliary heating device for heating the air supplied to the vehicle interior is provided. The control device is characterized in that, considering the rotational speed limit control, the heating capacity by the radiator is supplemented by heating by the auxiliary heating device.
According to a second aspect of the present invention, there is provided an air conditioner for a vehicle according to the present invention, wherein the control device is configured so that the suction refrigerant temperature or the suction refrigerant pressure of the compressor does not fall below a predetermined limit target value in the rotational speed restriction control. The number of rotations is limited, or the compressor rotation number is limited so that the discharge refrigerant temperature or discharge refrigerant pressure of the compressor does not rise above a predetermined limit target value, and heat is released based on the maximum rotation number NCmax of the compressor. HP maximum capacity estimated value Qmax, which is an estimated value of the maximum heating capacity of the radiator, is calculated, and a difference ΔQmax = TGQ−Qmax between required capacity TGQ, which is the required heating capacity of the radiator, and HP maximum capacity estimated value Qmax is calculated. Then, the required capacity TGQhtr of the auxiliary heating device is calculated from ΔQmax, heating by the auxiliary heating device is executed, and based on the rotation speed of the compressor limited by the rotation speed limit control. And the maximum rotational speed NCmax is changed.
A vehicle air conditioner according to a third aspect of the present invention is characterized in that, in the above invention, the control device sets the actual rotational speed of the compressor to the maximum rotational speed NCmax when the rotational speed limiting control is being executed. To do.
According to a fourth aspect of the present invention, there is provided a vehicle air conditioner according to the second or third aspect of the present invention, wherein the control device is limited by the rotational speed limiting control based on the outside air temperature when the rotational speed limiting control is not executed. The maximum value of the rotation speed of the compressor to be performed is estimated, and the estimated maximum value is set as the maximum rotation speed NCmax.
The vehicle air conditioner according to a fifth aspect of the present invention is the air conditioning apparatus for a vehicle according to the second to fourth aspects of the present invention, wherein the control device is configured such that the maximum rotational speed NCmax is based on the rotational speed of the compressor that is restricted by the rotational speed restriction control at the start of startup. It is characterized by changing.
In the vehicle air conditioner according to the sixth aspect of the present invention, in the above invention, the control device calculates an HP actual capacity Qhp which is a heating capacity actually generated by the radiator, and a difference between the required capacity TGQ and the HP actual capacity Qhp. ΔQhp = TGQ−Qhp is calculated, and after the initial startup period has elapsed, the required capacity TGQhtr of the auxiliary heating device is obtained from ΔQhp, and heating by the auxiliary heating device is executed.

According to the present invention, a compressor that compresses a refrigerant, a radiator that heats air that radiates the refrigerant and is supplied to the vehicle interior, and an outdoor heat exchanger that is provided outside the vehicle cabin and absorbs heat from the refrigerant. And a control device. The control device radiates the refrigerant discharged from the compressor with a radiator, depressurizes the radiated refrigerant, and then absorbs heat with an outdoor heat exchanger. In the vehicle air conditioner that performs the rotation speed limit control for limiting the rotation speed of the compressor and protecting the compressor while heating, an auxiliary heating device for heating the air to be supplied to the vehicle interior is provided, Considering the rotational speed limit control, the controller supplements the shortage of the heating capacity by the radiator with the heating by the auxiliary heating device. Heating capacity, auxiliary heating device According without any trouble supplemented by heating, so that it is possible to realize a comfortable passenger compartment heating.
In particular, as in the invention of claim 2, the control device limits the rotation speed of the compressor so that the suction refrigerant temperature or the suction refrigerant pressure of the compressor does not fall below a predetermined limit target value in the rotation speed limit control, or In addition, the rotation speed of the compressor is limited so that the discharge refrigerant temperature or the discharge refrigerant pressure of the compressor does not exceed a predetermined limit target value, and the maximum heating capacity of the radiator is estimated based on the maximum rotation speed NCmax of the compressor HP maximum capacity estimated value Qmax, which is a value, is calculated, and difference ΔQmax = TGQ-Qmax between required capacity TGQ, which is the required heating capacity of the radiator, and HP maximum capacity estimated value Qmax is calculated, and the requirement of the auxiliary heating device The capacity TGQhtr is calculated from ΔQmax, heating by the auxiliary heating device is executed, and the maximum rotational speed NCmax is changed based on the rotational speed of the compressor limited by the rotational speed limiting control. In addition, the maximum number of revolutions NCmax, which is the basis for calculating the HP maximum capacity estimated value Qmax, is changed based on the number of revolutions of the compressor limited by the number of revolutions limiting control, and the auxiliary heating calculated from ΔQmax The required capacity TGQhtr of the apparatus is increased by that amount, and the reduced amount of the heating capacity of the radiator can be appropriately compensated.
In this case, when the control device is executing the rotational speed limit control as in the invention of claim 3, the actual rotational speed of the compressor is set to the maximum rotational speed NCmax, so that the actual rotational speed limit control is actually performed. The HP maximum capacity estimated value Qmax is calculated from the limited rotation speed of the compressor, and the required capacity TGQhtr of the auxiliary heating device can be accurately calculated.
On the other hand, when the rotational speed restriction control is not being executed, the control device as in the invention of claim 4 estimates the maximum value of the rotational speed of the compressor restricted by the rotational speed restriction control based on the outside air temperature, and By setting the estimated maximum value as the maximum rotation speed NCmax, even when the rotation speed limitation control is started thereafter, the heating capacity by the auxiliary heating device can be complemented quickly.
In particular, if the control device changes the maximum rotational speed NCmax based on the rotational speed of the compressor that is restricted by the rotational speed restriction control in the initial stage of startup as in the invention of claim 5, the vehicle interior heating is started. It is possible to increase speed and improve comfort.
Further, as in the invention of claim 6, the control device calculates the HP actual capacity Qhp which is the heating capacity actually generated by the radiator, and calculates the difference ΔQhp = TGQ−Qhp between the required capacity TGQ and the HP actual capacity Qhp. At the same time, after the initial startup period has elapsed, the required capacity TGQhtr of the auxiliary heating device is obtained from ΔQhp and heating by the auxiliary heating device is performed. A shortage of the actual HP capacity Qhp, which is the heating capacity of the radiator that actually occurs, can be complemented by heating with the auxiliary heating device with respect to the capacity TGQ, realizing extremely comfortable interior heating. Will be able to.

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 electric circuit of the controller of the vehicle air conditioner of FIG. It is an enlarged view of the air flow path part of the air conditioning apparatus for vehicles of FIG. It is a flowchart explaining the energy saving priority mode in the heating mode by the controller of FIG. It is a data table which shows the relationship between outside temperature Tam and the maximum rotational speed estimated value QmaxNCTam at the time of rotational speed restriction control. It is a figure explaining the change of the upper limit rotation speed TGNCcomf in the comfort priority mode in the heating mode by the controller of FIG. It is a flowchart explaining the comfort priority mode in the heating mode by the controller of FIG.

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 as an embodiment of the present invention. In this case, the vehicle of the embodiment to which the present invention is applied is an electric vehicle (EV) that does not have an engine (internal combustion engine), and travels by driving an electric motor for traveling with electric power charged in a battery. The vehicle air conditioner 1 of the present invention is also driven by battery power.
That is, the vehicle air conditioner 1 of the embodiment performs heating by a heat pump operation using a refrigerant circuit in an electric vehicle that cannot be heated by engine waste heat, and further operates in each operation mode such as dehumidifying heating, dehumidifying cooling, and cooling. 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. Furthermore, the present invention is also applicable to a normal automobile that runs on an engine.
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 is electrically powered by compressing a refrigerant and increasing pressure by being supplied with power from a vehicle battery. A compressor 2 of the type, and a radiator 4 provided in the air flow passage 3 of the HVAC unit 10 through which air in the passenger compartment is circulated to dissipate high-temperature and high-pressure refrigerant discharged from the compressor 2 into the passenger compartment, An outdoor expansion valve (ECCV) 6 comprising an electronic expansion valve that decompresses and expands the refrigerant during heating, and an outdoor that functions as a radiator during cooling and performs heat exchange between the refrigerant and the outside air to function as an evaporator during heating A heat exchanger 7, an indoor expansion valve 8 comprising an electronic expansion valve (which may be a mechanical expansion valve) that expands the refrigerant under reduced pressure, and a refrigerant that is provided in the air flow passage 3 from outside the vehicle interior during cooling and dehumidifying heating. Heat absorber to absorb heat When, the evaporation capacity control valve 11 for adjusting the evaporating ability in the heat sink 9, an accumulator 12 and the like are sequentially connected by a refrigerant pipe 13, the refrigerant circuit R is formed.
The outdoor heat exchanger 7 is provided outside the vehicle compartment, and the outdoor heat exchanger 7 is provided with an outdoor blower 15 for exchanging heat between the outside air and the refrigerant when the vehicle is stopped. The outdoor heat exchanger 7 has a header portion 14 and a supercooling portion 16 in order on the downstream side of the refrigerant, and the refrigerant pipe 13A exiting from the outdoor heat exchanger 7 has an electromagnetic valve (open / close valve) 17 that is opened during cooling. The outlet of the supercooling unit 16 is connected to the indoor expansion valve 8 via a check valve 18. The header portion 14 and the supercooling portion 16 structurally constitute a part of the outdoor heat exchanger 7, and the check valve 18 has a forward direction on the indoor expansion valve 8 side.
Further, the refrigerant pipe 13B between the check valve 18 and the indoor expansion valve 8 is provided in a heat exchange relationship with the refrigerant pipe 13C exiting the evaporation capacity control valve 11 located on the outlet side of the heat absorber 9, and internal heat is generated by both. The exchanger 19 is configured. 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 and passed through the evaporation capacity control valve 11.
Further, the refrigerant pipe 13A exiting from the outdoor heat exchanger 7 is branched, and this branched refrigerant pipe 13D is downstream of the internal heat exchanger 19 via an electromagnetic valve (open / close valve) 21 that is opened during heating. The refrigerant pipe 13C is connected in communication. Further, the refrigerant pipe 13E on the outlet side of the radiator 4 is branched in front of the outdoor expansion valve 6, and this branched refrigerant pipe 13F is a check valve via an electromagnetic valve (open / close valve) 22 that is opened during dehumidification. 18 is connected to the refrigerant pipe 13B on the downstream side.
Further, in the air flow passage 3 on the air upstream side of the heat sink 9, each of the inside air suction port and the outside air suction port (represented by the suction port 25 in FIG. 1) is formed. 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 has shown the heat-medium circulation circuit as an auxiliary | assistant heating apparatus provided in the vehicle air conditioner 1 of the Example. This heat medium circulation circuit 23 is on the air upstream side of the radiator 4 with respect to the air flow in the circulation pump 30 constituting the circulation means, the heat medium heating electric heater (PTC heater) 35, and the air flow passage 3. A heat medium-air heat exchanger 40 provided in the air flow passage 3 is provided, and these are sequentially connected in an annular shape by a heat medium pipe 23A. As the heat medium circulated in the heat medium circuit 23, for example, water, a refrigerant such as HFO-1234yf, a coolant, or the like is employed.
When the circulation pump 30 is operated and the heat medium heating electric heater 35 is energized to generate heat, the heat medium (high temperature heat medium) heated by the heat medium heating electric heater 35 is converted into the heat medium-air heat exchanger 40. Thus, the air that has passed through the radiator 4 in the air flow path 3 is heated. When the controller 32 determines that the heating capability of the radiator 4 is insufficient in the heating mode as will be described later, the heat medium heating electric heater 35 is energized to generate heat, and the circulation pump 30 is operated, whereby the heat medium circulation circuit 23. The heating by the heat medium-air heat exchanger 40 is executed. That is, the heat medium-air heat exchanger 40 of the heat exchanger circulation circuit 23 serves as a so-called heater core, and complements heating in the passenger compartment. By adopting such a heat medium circulation circuit 23, the passenger's electrical safety is improved.
An air mix damper 28 is provided in the air flow passage 3 on the air upstream side of the heat medium-air heat exchanger 40 and the radiator 4 to adjust the degree of flow of inside air and outside air to the radiator 4. . Further, in the air flow passage 3 on the downstream side of the radiator 4, foot, vent, and differential air outlets (represented by the air outlet 29 in FIG. 1) are formed. Is provided with a blower outlet switching damper 31 for switching and controlling the blowing of air from each of the blowout ports.
Next, in FIG. 2, reference numeral 32 denotes a controller (ECU) as a control means constituted by a microcomputer, and an input from the controller 32 includes an outside air temperature sensor 33 for detecting the outside air temperature Tam of the vehicle, and a suction port 25. An HVAC suction temperature sensor 36 for detecting the temperature sucked into the air flow passage 3, an inside air temperature sensor 37 for detecting the temperature of the air (inside air) in the passenger compartment, and an inside air humidity sensor 38 for detecting the humidity of the air in the passenger compartment. , Indoor CO to detect the carbon dioxide concentration in the passenger compartment ₂ Concentration sensor 39, blowout temperature sensor 41 that detects the temperature of air blown into the vehicle interior from the blowout port 29, discharge pressure sensor 42 that detects the discharge refrigerant pressure Pd of the compressor 2, and discharge refrigerant of the compressor 2 The discharge temperature sensor 43 that detects the temperature Td, the suction temperature sensor 45 that detects the suction refrigerant temperature Ts of the compressor 2, the suction pressure sensor 44 that detects the suction refrigerant pressure Ps of the compressor 2, and the temperature of the radiator 4 A radiator temperature sensor 46 that detects TCI (the temperature of the radiator 4 itself or the temperature of the air on the downstream side of the radiator 4 heated by the radiator 4), and the refrigerant pressure PCI (radiation of the radiator 4) A pressure sensor 47 for detecting the pressure of the refrigerant exiting the radiator 4 or the pressure of the refrigerant exiting the radiator 4 and the temperature Te of the heat absorber 9 (the heat absorber 9 itself or the air cooled by the heat absorber 9). Temperature sensor) 48, a heat absorber pressure sensor 49 for detecting the refrigerant pressure of the heat absorber 9 (the pressure of the refrigerant in the heat absorber 9 or the refrigerant that has exited the heat absorber 9), and a photo for detecting the amount of solar radiation into the passenger compartment, for example A sensor-type solar radiation sensor 51, a vehicle speed sensor 52 for detecting the moving speed of the vehicle (vehicle speed VSP), an air-conditioning operation unit 53 for setting temperature and operation mode switching, and the temperature of the outdoor heat exchanger 7 The outputs of the outdoor heat exchanger temperature sensor 54 for detecting the refrigerant evaporating temperature TXO of the outdoor heat exchanger 7 and the outdoor heat exchanger pressure sensor 56 for detecting the refrigerant pressure of the outdoor heat exchanger 7 are connected. Yes.
When the radiator temperature TCI is set as the air temperature downstream of the radiator 4, the controller 32 may estimate it from the temperature of each part detected by another temperature sensor or the like, the air flow rate, and the like.
Further, the input of the controller 32 further includes a heat medium heating electric heater temperature sensor 50 that detects the temperature of the heat medium heating electric heater 34 of the heat medium circulation circuit 23, and the temperature of the heat medium-air heat exchanger 40 (hereinafter, Each output of the heat medium-air heat exchanger temperature sensor 55 for detecting the auxiliary heater temperature Thtr) is also connected. Further, the controller 32 is also input with information on the remaining amount of the battery, which is the charge amount of the battery mounted on the vehicle.
On the other hand, the output of the controller 32 includes the compressor 2, the outdoor blower 15, the indoor blower (blower fan) 27, the suction switching damper 26, the air mix damper 28, the outlet switching damper 31, and the outdoor expansion. The valve 6, the indoor expansion valve 8, the

electromagnetic valves

22, 17, 21, the circulation pump 30, the heat medium heating electric heater 35, and the evaporation capacity control valve 11 are connected. And the controller 32 controls these based on the output of each sensor, and the setting input in the air-conditioning operation part 53. FIG.
Next, the operation of the vehicle air conditioner 1 having the above-described configuration will be described. In the embodiment, the controller 32 is roughly divided into a heating mode, a dehumidifying heating mode, an internal cycle mode, a dehumidifying cooling mode, and a cooling mode, and executes them. First, the refrigerant flow in each operation mode will be described.
(1) Heating mode
When the heating mode is selected by the controller 32 or by manual operation on the air conditioning operation unit 53, the controller 32 opens the electromagnetic valve 21 and closes the electromagnetic valve 17 and the electromagnetic valve 22. Then, the compressor 2 and the

blowers

15 and 27 are operated, and the air mix damper 28 is in a state where the air blown out from the indoor blower 27 is passed through the heat medium-air heat exchanger 40 and the radiator 4. . Thereby, the high-temperature and high-pressure gas refrigerant discharged from the compressor 2 flows into the radiator 4. 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 heat medium-air heat exchanger 40 (the heat medium circulation circuit 23 is activated). In the case), it is heated by the high-temperature refrigerant in 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 reaches the outdoor expansion valve 6 through the refrigerant pipe 13E, is decompressed there, and then flows into the outdoor heat exchanger 7. The refrigerant that has flowed into the outdoor heat exchanger 7 evaporates, and pumps heat from the outside air that is ventilated by traveling or by the outdoor blower 15 (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 13D and the electromagnetic valve 21, and after being gas-liquid separated there, the gas refrigerant is sucked into the compressor 2. repeat. Since the air heated by the heat medium-air heat exchanger 40 or the radiator 4 is blown out from the air outlet 29, the vehicle interior is thereby heated.
The controller 32 controls the rotational speed NC of the compressor 2 on the basis of the high pressure of the refrigerant circuit R detected by the discharge pressure sensor 42 or the radiator pressure sensor 47 (a radiator pressure PCI to be described later), and the radiator temperature sensor 46. Controls the opening degree of the outdoor expansion valve 6 based on the temperature of the radiator 4 (radiator temperature TCI) detected by, and controls the refrigerant subcooling degree SC at the outlet of the radiator 4.
(2) Dehumidification heating mode
Next, in the dehumidifying and heating mode, the controller 32 opens the electromagnetic valve 22 in the heating mode. As a result, a part of the condensed refrigerant flowing through the refrigerant pipe 13E via the radiator 4 is diverted to reach the indoor expansion valve 8 via the electromagnetic valve 22 and the

refrigerant pipes

13F and 13B via the internal heat exchanger 19. After the refrigerant is depressurized by the indoor expansion valve 8, it flows into the heat absorber 9 and evaporates. 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 merges with the refrigerant from the refrigerant pipe 13D in the refrigerant pipe 13C through the evaporation capacity control valve 11 and the internal heat exchanger 19, and then repeats circulation 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.
The controller 32 controls the rotational speed NC of the compressor 2 based on the high pressure of the refrigerant circuit R detected by the discharge pressure sensor 42 or the radiator pressure sensor 47 and the temperature of the heat absorber 9 detected by the heat absorber temperature sensor 48. The valve opening degree of the outdoor expansion valve 6 is controlled based on the (heat absorber temperature Te).
(3) Internal cycle mode
Next, in the internal cycle mode, the controller 32 closes the outdoor expansion valve 6 in the state of the dehumidifying and heating mode (fully closed). That is, since this internal cycle mode can be said to be a state in which the outdoor expansion valve 6 is fully closed by the control of the outdoor expansion valve 6 in the dehumidifying and heating mode, the internal cycle mode can also be regarded as a part of the dehumidifying and heating mode.
However, since the inflow of the refrigerant to the outdoor heat exchanger 7 is blocked by closing the outdoor expansion valve 6, the condensed refrigerant flowing through the refrigerant pipe 13E via the radiator 4 passes through the electromagnetic valve 22 to the refrigerant pipe 13F. Everything starts to flow. And the refrigerant | coolant which flows through the refrigerant | coolant piping 13F reaches the indoor expansion valve 8 through the internal heat exchanger 19 from the refrigerant | coolant piping 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 flows through the refrigerant pipe 13C through the evaporation capacity control valve 11 and the internal heat exchanger 19, 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, dehumidification heating is performed in the vehicle interior, but in this internal cycle mode, the air flow path on the indoor side 3, the refrigerant is circulated between the radiator 4 (heat radiation) and the heat absorber 9 (heat absorption) in the heat pump 3, so that heat is not pumped from the outside air, and the heat absorber 9 is used for the power consumption of the compressor 2. Heating capacity is displayed as much as the amount of heat absorbed is added. 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.
Further, the controller 32 controls the rotational speed NC of the compressor 2 based on the temperature of the heat absorber 9 or the high pressure of the refrigerant circuit R described above. At this time, the controller 32 controls the compressor 2 by selecting the lower one of the compressor target rotational speeds obtained from either calculation, depending on the temperature Te of the heat absorber 9 or the high pressure PCI.
(4) Dehumidifying and cooling mode
Next, in the dehumidifying and cooling mode, the controller 32 opens the electromagnetic valve 17 and closes the electromagnetic valve 21 and the electromagnetic valve 22. Then, the compressor 2 and the

blowers

15 and 27 are operated, and the air mix damper 28 is in a state where the air blown out from the indoor blower 27 is passed through the heat medium-air heat exchanger 40 and the radiator 4. . Thereby, the high-temperature and high-pressure gas refrigerant discharged from the compressor 2 flows into the radiator 4. 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 (the heat medium circulation circuit 40 is stopped). The refrigerant in 4 is deprived of heat by the air and cooled to condensate.
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 into the header section 14 and the supercooling section 16 from the refrigerant pipe 13A through the electromagnetic valve 17. 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 through the check valve 18, and 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 passes through the evaporation capacity control valve 11 and the internal heat exchanger 19, reaches the accumulator 12 through the refrigerant pipe 13 C, and repeats circulation sucked into the compressor 2 through the refrigerant pipe 13 C. The air cooled and dehumidified by the heat absorber 9 is reheated (having a lower heat dissipation capacity than that during heating) in the process of passing through the radiator 4, thereby dehumidifying and cooling the vehicle interior. .
The controller 32 controls the rotational speed NC of the compressor 2 based on the temperature of the heat absorber 9 detected by the heat absorber temperature sensor 48, and expands outdoors based on the high pressure (radiator pressure PCI) of the refrigerant circuit R described above. The valve opening degree of the valve 6 is controlled, and the refrigerant pressure of the radiator 4 (a radiator pressure PCI described later) is controlled.
(5) Cooling mode
Next, in the cooling mode, the controller 32 fully opens the outdoor expansion valve 6 (the valve opening is the upper limit of control) in the dehumidifying and cooling mode state, and the air mix damper 28 is in a state where air is not passed through the radiator 4. Thereby, the high-temperature and high-pressure gas refrigerant discharged from the compressor 2 flows into the radiator 4. Since the air in the air flow passage 3 is not ventilated to the radiator 4, it only passes here, and the refrigerant exiting the radiator 4 reaches the outdoor expansion valve 6 via the refrigerant pipe 13E.
At this time, since the outdoor expansion valve 6 is fully opened, the refrigerant flows into the outdoor heat exchanger 7 as it is, where it is cooled by air or by outside air ventilated by the outdoor blower 15 to be condensed and liquefied. The refrigerant that has exited the outdoor heat exchanger 7 sequentially flows into the header section 14 and the supercooling section 16 from the refrigerant pipe 13A through the electromagnetic valve 17. 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 through the check valve 18, and 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.
The refrigerant evaporated in the heat absorber 9 passes through the evaporation capacity control valve 11 and the internal heat exchanger 19, reaches the accumulator 12 through the refrigerant pipe 13 C, and repeats circulation sucked into the compressor 2 through the refrigerant pipe 13 C. The air that has been cooled and dehumidified by the heat absorber 9 is blown into the vehicle interior from the outlet 29 without passing through the radiator 4, thereby cooling the vehicle interior. In this cooling mode, the controller 32 controls the rotational speed NC of the compressor 2 based on the temperature Te of the heat absorber 9 detected by the heat absorber temperature sensor 48. And the controller 32 selects and switches each said operation mode according to outside temperature or target blowing temperature.
(6) Control of compressor and heating medium circulation circuit in heating mode
Next, control of the compressor 2 and the heat medium circulation circuit 23 of the controller 32 in the heating mode described above will be described with reference to FIGS.
(6-1) Calculation of compressor target rotation speed (high pressure calculation rotation speed TGNChp) by high pressure
The controller 32 calculates the target blowing temperature TAO from the following formula (I). This target blowing temperature TAO is a target value of the air temperature blown out from the blowout port 29 into the vehicle interior.
TAO = (Tset−Tin) × K + Tbal (f (Tset, SUN, Tam))
.. (I)
Here, Tset is the set temperature in the passenger compartment set by the air conditioning operation unit 53, Tin is the temperature of the passenger compartment air detected by the inside air temperature sensor 37, K is a coefficient, Tbal is the set temperature Tset, and the solar radiation sensor 51 detects This is a balance value calculated from the amount of solar radiation SUN to be performed and 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.
The controller 32 calculates a target radiator temperature TCO from the target outlet temperature TAO, and then calculates a target radiator pressure PCO that is a target value of the high pressure of the refrigerant circuit R based on the target radiator temperature TCO. Based on the target radiator pressure PCO and the refrigerant pressure (radiator pressure, ie, high pressure of the refrigerant circuit R) PCI of the radiator 4 detected by the radiator pressure sensor 47, the controller 32 A high-pressure calculated rotational speed TGNChp, which is a target value for the rotational speed Nc, is calculated.
That is, the high-pressure calculated rotation speed TGNChp is a compressor 2 for controlling the radiator pressure PCI (high pressure) to the target radiator pressure PCO (target value of high pressure) by the rotation speed Nc of the compressor 2. For example, in an environment where the outside air temperature Tam is low, the pressure of the refrigerant sucked into the compressor 2 decreases, and the suction refrigerant temperature Ts of the compressor 2 also decreases. In such a state, since the pressure difference between the suction and discharge of the compressor 2 becomes excessive and there is a risk of causing damage, the controller 32 of the embodiment executes the rotation speed limit control described below.
(6-2) Speed limit control based on the suction refrigerant temperature Ts
That is, the controller 32 according to the embodiment executes the rotational speed limit control of the compressor 2 based on the suction refrigerant temperature Ts detected by the suction temperature sensor 45. The rotation speed limitation control of the embodiment limits (decreases) the rotation speed NC of the compressor 2 so that the suction refrigerant temperature Ts does not fall below a predetermined limit target value TGTs (for example, −22 ° C. or the like) for low pressure protection. ) Protection control.
In the case of the embodiment, the controller 32 constantly monitors the suction refrigerant temperature Ts, and the difference (Ts−TGTs) between the suction refrigerant temperatures Ts, which is a detection value detected by the suction temperature sensor 45 from the limit target value TGTs, is predetermined. The final value (after restriction) is selected by selecting the smaller value (MIN) of the value obtained by adding the previous gain to the value obtained by adding the previous high-pressure calculated rotation speed TGNChppst and the currently calculated high-pressure calculated rotation speed TGNChhp. The rotation speed is determined as TGNChp.
That is, when the suction refrigerant temperature Ts becomes lower than the limit target value TGTs, a value obtained by multiplying the difference (Ts−TGTs) by a predetermined gain is always negative, and therefore the predetermined gain is added to the difference (Ts−TGTs). The value obtained by adding the previous high-pressure calculated rotation speed TGNChppst to the multiplied value is lower than the previous high-pressure calculated rotation speed TGNChppst. When the value obtained by adding a predetermined gain to the difference (Ts−TGTs) and the previous high-pressure calculated rotational speed TGNChppst is smaller than the currently calculated high-pressure calculated rotational speed TGNChpp, the value is If it is larger, the currently calculated high-pressure calculated rotational speed TGNChp is selected. In any case, if the suction refrigerant temperature Ts is lower than the limit target value TGTs, the high-pressure calculated rotational speed TGNChp is reduced. become.
Thereby, the controller 32 protects the compressor 2 by restricting the rotational speed NC of the compressor 2 so that the suction refrigerant temperature Ts does not fall below the restriction target value TGTs. Therefore, when the rotation speed NC is limited by the rotation speed limitation control, the heating capacity of the radiator 4 is reduced accordingly.
(6-3) Switching between energy-saving priority mode and comfort priority mode
Further, in this heating mode, the controller 32 has two types of operation modes, an energy saving priority mode and a comfort priority mode, which will be described below in the embodiment, and a manual selection operation by the passenger using the air conditioning operation unit 53. Alternatively, these are switched and executed depending on the remaining battery level.
First, when the passenger operates the air conditioning operation unit 53 to select the energy saving priority mode, or when the remaining battery level of the vehicle falls below a predetermined value, the controller 32 executes the energy saving priority mode described later. If the energy saving priority mode is not selected by the passenger and the remaining battery level is equal to or greater than the predetermined value, the comfort priority mode described later is executed.
(6-4) Energy saving priority mode in heating mode
Hereinafter, the energy saving priority mode of the controller 32 described above will be described with reference to FIGS. 4 and 5. In the energy saving priority mode, the controller 32 operates the compressor 2 with the rotational speed NC of the compressor 2 as the maximum rotational speed NCmax that can be operated under the conditions, and the heating medium circulation due to the lack of heating capacity by the radiator 4 is circulated. It supplements with the heating by the circuit 23 (heat medium-air heat exchanger 40). However, as described above, in the rotational speed limit control, the rotational speed NC is limited, and the maximum operable rotational speed NCmax is also lowered. The controller 32 supplements the heating capability of the radiator 4 in consideration of the limited number of revolutions NC, which will be described in detail later.
That is, the controller 32 determines in step S1 in FIG. 4 whether or not a failure has occurred in the heat pump (indicated by HP in FIG. 4) including the refrigerant circuit R of the vehicle air conditioner 1, and the failure has not been determined. If N), the heat pump (compressor 2) is stopped in step S5. In step S6, the HP maximum capacity estimated value Qmax, which will be described later, is set to zero (Qmax = 0).
If the failure is not determined in step S1 and is normal (Y), the process proceeds to step S2, and it is determined whether or not the operation mode of the vehicle air conditioner 1 is the current heating mode. If it transfers to another operation mode and it is heating mode (Y), it will progress to step S3. In this step S3, the controller 32 determines that the required capacity TGQ (kW), which is the heating capacity of the radiator 4 required using the following formula (II), formula (III), and formula (IV), and that the radiator 4 is actually HP actual capacity Qhp (kW) which is the heating capacity generated in the heat generator, the radiator 4 and the heat medium circulation circuit 23 (including the heat medium-air heat exchanger 40 which is an auxiliary heating device; the same applies hereinafter). The total capacity Qtotal (kW), which is the total heating capacity, is calculated.
TGQ = (TCO−Te) × Cpa × real Ga × γaTe × 1.16 (II)
Qhp = (TCI−Thtr) × Cpa × real Ga × (SW / 100) × γaTe
× 1.16 (III)
Qtotal = (TCI−Te) × Cpa × real Ga × (SW / 100) × γaTe
× 1.16 (IV)
Te is the heat absorber temperature, Cpa is the constant pressure specific heat of air [kJ / m ³ K], real Ga is the actual air volume of the air flowing through the air flow passage 3 (actual system air volume m ³ / S), γaTe is the specific gravity of air, 1.16 is a coefficient for matching the units, NCmax is the maximum number of revolutions at which the compressor 2 can be operated under the conditions, and Thtr is the temperature of the heat medium-air heat exchanger 40 A certain auxiliary heater temperature, TCI, is the radiator temperature (in this case, the air temperature downstream of the radiator 4 described above), and SW is the opening of the air mix damper 28.
Further, the controller 32 calculates a difference ΔQhp between the required capacity TGQ and the HP actual capacity Qhp and a difference ΔQtotal between the required capacity TGQ and the overall capacity Qtotal using the following formulas (V) and (VI).
ΔQhp = TGQ−Qhp (V)
ΔQtotal = TGQ−Qtotal (VI)
Next, the controller 32 determines whether or not the heat pump (compressor 2) is stopped due to frosting of the outdoor heat exchanger 7 in step S4. If the frost formation of the outdoor heat exchanger 7 increases, heat absorption from the outside air (heat pump) cannot be performed even when the compressor 2 of the refrigerant circuit R is operated, and the operation efficiency is significantly reduced. Based on the frosting determination value ΔTXO (ΔTXO = TXObase−TXO), which is the difference between the refrigerant evaporation temperature TXObase of the outdoor heat exchanger 7 and the current refrigerant evaporation temperature TXO at the time of no frosting in step S4, the controller 32 When the degree of frost formation (frost formation rate) of the exchanger 7 is calculated and the degree of frost formation exceeds a predetermined value (Y, HP stopped), the process proceeds to step S5 and the heat pump (the compressor 2 of the refrigerant circuit R) To stop.
When it is not determined in step S4 that the heat pump (compressor 2) is stopped (N, HP operation), the controller 32 sets the rotation speed NC of the compressor 2 as the maximum rotation speed NCmax operable under the conditions. 2, the process proceeds to step S9, and it is determined whether or not the rotation speed limit control (limitation by the suction refrigerant temperature Ts. Ts limit) is currently being executed. If the current rotation speed limit control is being executed (Ts is being limited), the process proceeds to step S10, where the maximum rotation speed NCmax is set to the actual rotation speed NC of the compressor 2 at the present time (NCmax = actual NC). That is, at this time, since the rotational speed limit control is performed, the actual rotational speed NC of the compressor 2 is decreased. Accordingly, the maximum rotational speed NCmax is also lowered accordingly. Thereafter, the controller 32 proceeds to step S11.
On the other hand, when the current rotation speed limit control is not being executed in step S9, the controller 32 proceeds to step S14, and sets the maximum rotation speed NCmax to the maximum rotation speed estimated value QmaxNCTam during the rotation speed limit control (NCmax = QmaxNCTam). The maximum rotational speed estimated value QmaxNCTam is an estimate of the maximum value of the rotational speed NC of the compressor 2 that is limited by the rotational speed limiting control from the outside air temperature Tam, assuming that the rotational speed limiting control is performed. FIG. 5 is a graph showing the relationship between the outside air temperature Tam and the maximum rotational speed estimated value QmaxNCTam for this purpose. The graph of FIG. 5 is held by the controller 32 as a data table.
In the graph (data table) of FIG. 5, the horizontal axis indicates the outside air temperature Tam detected by the outside air temperature sensor 33, and the vertical axis indicates the maximum rotational speed estimated value QmaxNCTam. As described above, the controller 32 limits the rotation speed NC of the compressor 2 so that the suction refrigerant temperature Ts of the compressor 2 does not fall below a predetermined value (−22 ° C. in the embodiment of the limit target value TGTs) by the rotation speed limit control. However, since the suction refrigerant temperature Ts of the compressor 2 is strongly influenced by the outside air temperature Tam, the state of this restriction can be estimated from the outside air temperature Tam.
Therefore, in the embodiment (FIG. 5), the controller 32 sets the maximum rotational speed estimated value QmaxNCTam to 7000 rpm (maximum rotational speed for control) until the outdoor air temperature Tam drops to −10 ° C., and the outdoor air temperature Tam decreases from −10 ° C. Accordingly, the maximum rotational speed estimated value QmaxNCTam is reduced to 3000 rpm when the outside air temperature Tam is −20 ° C., for example. That is, this is presumed that the rotational speed limit control is performed (assumed to be performed) in an environment where the outside air temperature Tam is −20 ° C., and the rotational speed NC of the compressor 2 can be increased only to 3000 rpm at the maximum. Is meant to do.
In step S14, the controller 32 derives the maximum rotational speed estimated value QmaxNCTam at the time of the rotational speed restriction control from the graph of FIG. 5 based on the outside air temperature Tam, thereby limiting the rotational speed NC of the compressor 2 that is restricted by the rotational speed restriction control. The maximum value is estimated, and NCmax is set as the maximum rotational speed estimated value QmaxNCTam (NCmax = Ts limit rotational speed estimated value QmaxNCTam). That is, since the rotational speed limit control is performed immediately under an environment where the outside air temperature Tam is low, the maximum rotational speed NCmax is lowered so that the rotational speed limit control may be performed thereafter.
After the maximum rotational speed NCmax of the compressor 2 is set to the actual rotational speed NC or the maximum rotational speed estimated value QmaxNCTam during the rotational speed limiting control in the above steps S10 and S14, the controller 32 proceeds to step S11. Then, using the maximum rotational speed NCmax set in step S10 or step S14 in step S11, the HP maximum capacity estimated value Qmax that is the estimated value of the maximum heating capacity of the radiator 4 is calculated using the following formula (VII). calculate.
Qmax = f (Tam, Ga, NCmax, Thtr-Te) (VII)
Note that Te is the heat absorber temperature, Tam is the outside air temperature, Ga is the air volume of the air flowing through the air flow passage 3, and Thtr is the auxiliary heater temperature which is the temperature of the heat medium-air heat exchanger 40. NCmax is the maximum rotational speed at which the compressor 2 can be operated. This NCmax is a value that takes into consideration the rotational speed limit control in step S10 or step S14 described above, and therefore the HP calculated in step S11. The maximum capacity estimation value Qmax also decreases as NCmax decreases in the rotation speed limit control.
Then, a difference ΔQmax between the required capacity TGQ and the HP maximum capacity estimated value Qmax is calculated using the following formula (VIII).
ΔQmax = TGQ−Qmax (VVIII)
FIG. 3 shows the relationship between the above-described ability and the difference. As described above, when Qmax is lowered in consideration of the rotational speed limiting control, the difference ΔQmax is increased.
Then, the controller 32 proceeds to step S12 and makes a determination based on actual ability. In this embodiment, the determination based on the actual capacity means that the rotational speed NC of the compressor 2 is the maximum rotational speed NCmax, the high pressure (radiator pressure PCI) of the refrigerant circuit R is stable, and ΔQtotal is a predetermined value. It is a determination as to whether or not a predetermined time (for example, 30 seconds) has elapsed when all of the above conditions are satisfied. Advances to step S15 as (N) in step S12, and this time the determination based on the MAX ability is performed.
This determination based on the MAX capacity is executed immediately after the start of the compressor 2 until the high pressure is stabilized (in the case of N in step S12). In the embodiment, the required capacity TGQ and the HP maximum capacity estimated value Qmax are This is a determination as to whether or not the difference ΔQmax (= TGQ−Qmax) is equal to or greater than a predetermined value (a state where the maximum heating capacity (estimated value) of the radiator 4 is insufficient with respect to the required capacity TGQ), and is less than the predetermined value When the state is continued for a predetermined time (for example, 30 seconds), that is, when the maximum heating capacity (estimated value) of the radiator 4 satisfies the required capacity TGQ or is almost insufficient ( N) Proceeding to step S17, the heat medium heating electric heater 35 of the heat medium circulation circuit 23 is deenergized (PTC stop), and the required capacity TGQhtr of the heat medium circulation circuit 23 (auxiliary heating device) is made zero.
When the compressor 2 is started, the difference ΔQmax (= TGQ−Qmax) between the required capacity TGQ and the HP maximum capacity estimated value Qmax is greater than or equal to a predetermined value in step S15 (the maximum heating capacity (estimated value) of the radiator 4 with respect to the required capacity TGQ. ) Is insufficient) (Y), the controller 32 proceeds to step S16, the F / F (feed forward) value Qaff of the required capacity TGQhtr of the heat medium circulation circuit 23 is set to ΔQmax, and F / B ( Feedback) The value Qafb is set to zero.
Next, the process proceeds to step S8, where the controller 32 calculates the required capacity TGQhtr of the heat medium circulation circuit 23. In step S8, the controller 32 calculates the required capacity TGQhtr of the heat medium circulation circuit 23 using the following formula (IX).
TGQhtr = (Qaff + Qafb) / Φ (IX)
Here, Φ is the temperature efficiency (heater temperature efficiency) of the heat medium circulation circuit 23 (heat medium heating electric heater 35).
After the compressor 2 reaches the maximum rotational speed NCmax, the difference ΔQtotal between the required capacity TGQ and the overall capacity Qtotal becomes less than a predetermined value (N) in step S12, and the process proceeds to step S15 to estimate the required capacity TGQ and the HP maximum capacity. Even when the difference ΔQmax from the value Qmax is equal to or larger than the predetermined value, the controller 32 proceeds from step S16 to step S8 and calculates the required capacity TGQhtr of the heat medium circuit 23 by the above formula (IX). That is, since Qaff = ΔQmax and Qafb = 0 in step S16, the controller 32 sets the required capacity TGQhtr of the heat medium circulation circuit 23 to ΔQmax / Φ in step S8, and based on this required capacity TGQhtr, the heating medium heating electric heater 35 Control energization.
As described above, the difference ΔQmax is a value that takes into account the rotational speed limit control. When Qmax is low, the difference ΔQmax increases, and as a result, ΔQmax / Φ that is the required capacity TGQhtr of the heat medium circulation circuit 23 also increases. Thus, the heat generation amount of the heat medium heating electric heater 35 is also increased.
On the other hand, in step S12, the rotational speed NC of the compressor 2 is the maximum rotational speed NCmax, the high pressure (radiator pressure PCI) of the refrigerant circuit R is stable, and ΔQtotal is equal to or greater than a predetermined value for a predetermined time. If (Y), the controller 32 proceeds to step S13, sets the F / F value Qaff of the required capacity TGQhtr of the heat medium circuit 23 to ΔQmax, and sets the F / B value Qafb to the required capacity TGQ and the HP actual capacity Qhp. Difference QQhp, the process proceeds to step S8, and the required capacity TGQhtr of the heat medium circulation circuit 23 is calculated. That is, since Qaff = ΔQmax and Qafb = Qhp in step S13, the controller 32 sets the required capacity TGQhtr of the heat medium circulation circuit 23 to (ΔQmax + ΔQhp) / Φ in step S8, and based on this required capacity TGQhtr The energization of the heater 35 is controlled.
In this case as well, the difference ΔQmax is a value that takes into account the rotational speed limiting control. When Qmax is low, the difference ΔQmax increases, and thus the required capacity TGQhtr of the heat medium circuit 23 is (ΔQmax + ΔQhp) / Φ also increases and the amount of heat generated by the heat medium heating electric heater 35 also increases.
When the heat pump (compressor 2) is stopped in step S5, the controller 32 sets the HP maximum capacity estimated value Qmax to zero (Qmax = 0) in step S6, and then proceeds to step S7 to proceed to the heat medium circulation circuit 23. The F / F value Qaff of the required capacity TGQhtr is set to ΔQmax (= required capacity TGQ), the F / B value Qafb is set to zero, the process proceeds to step S8, and the required capacity TGQhtr of the heat medium circulation circuit 23 is calculated. That is, since Qaff = ΔQmax (= TGQ) and Qafb = 0 in step S7, the controller 32 sets the required capacity TGQhtr of the heat medium circulation circuit 23 to ΔQmax / Φ in step S8, and based on the required capacity TGQhtr The energization of the heating electric heater 35 is controlled.
(6-5) Comfort priority mode in heating mode
Next, the comfort priority mode of the controller 32 described above will be described with reference to FIGS. In the heating mode, when the energy saving priority mode is not selected by the passenger and the remaining battery level is equal to or higher than the predetermined value, the controller 32 executes the comfort priority mode as described above.
(6-5-1) Rotational speed control of the compressor 2 in the comfort priority mode
In this comfort priority mode, the controller 32 restricts the rotational speed NC of the compressor 2, and the heat capacity of the radiator 4 at the restricted rotational speed NC is reduced by the heat medium circulation circuit 23 (heat medium-air heat). Supplemented by heating with exchanger 40). First, the operation of limiting the rotational speed NC of the compressor 2 in the comfort priority mode will be described with reference to FIG.
The controller 32 uses the following formula (X) based on the vehicle speed VSP detected by the vehicle speed sensor 52, the blower voltage BLV, and the frosting determination value ΔTXO, and the upper limit rotation speed of the compressor 2 in the comfort priority mode. TGNCcomf is calculated.
TGNCcomf = MIN (TGNCcomfVSP, TGNCcomfBLV,
TGNCcomfΔTXO) (X)
Among these, the blower voltage BLV is the voltage of the indoor blower (blower fan) 27 and serves as an index indicating the amount of air flowing through the air flow passage 3. Further, the frosting determination value ΔTXO is a difference between the refrigerant evaporation temperature TXObase of the outdoor heat exchanger 7 and the current refrigerant evaporation temperature TXO (ΔTXO = TXObase−TXO) at the time of no frosting. The frost degree (frosting rate) is shown.
TGNCcomfVSP is the upper limit rotational speed of the compressor 2 calculated based on the vehicle speed. As shown in FIG. 6A, a predetermined lower limit value TGNCcomfLo (for example, about 3000 rpm) and an upper limit value TGNCcomfHi ( For example, as the vehicle speed VSP increases from 20 km / h to 80 km / h (ie, as the running sound increases), the speed increases at a predetermined change rate between 70 km / h and 10 km / h. As it decreases to h, it is changed so as to decrease at a predetermined change rate (with hysteresis).
Further, TGNCcomfBLV is the upper limit rotation speed of the compressor 2 calculated from the blower voltage. As shown in FIG. 6B, the blower voltage between the predetermined lower limit value TGNCcomfLo and the upper limit value TGNCcomfHi depends on the blower voltage BLV. For example, as the voltage BLV increases from 5 V to 14 V (that is, as the sound blown out by the indoor blower 27 increases), the voltage BLV increases at a predetermined change rate, and decreases from 13 V to 4 V at a predetermined change rate. It changes so that it goes (with hysteresis).
TGNCcomfΔTXO is the upper limit rotational speed of the compressor 2 calculated based on the degree of frost formation. As shown in FIG. 6C, the TGNCcomfΔTXO is between a predetermined lower limit value TGNCcomfLo and an upper limit value TGNCcomfHi according to the frost determination value ΔTXO. Thus, as the frosting determination value ΔTXO increases from, for example, 4 deg to 11 deg (that is, as the frosting of the outdoor heat exchanger 7 increases), the frosting determination value ΔTXO decreases with a predetermined rate of change. It is changed so as to increase at the rate of change (with hysteresis).
The controller 32 determines the smallest value among the changed upper limit rotational speeds TGNCcomfVSP, TGNCcomfBLV, TGNCcomfΔTXO as the upper limit rotational speed TGNCcomf of the compressor 2 in the comfort priority mode, using the equation (X).
Next, the controller 32 calculates the target rotational speed TGNC of the compressor 2 in the comfort priority mode using the following formula (XI).
TGNC = MIN (TGNCcomf, TGNChp) (XI)
The TGNChp is a high-pressure calculated rotational speed that is a target value of the rotational speed Nc of the compressor 2 calculated based on the target radiator pressure PCO and the radiator pressure PCI described above. That is, in the comfort priority mode, the controller 32 determines the smaller value of the above-described upper limit rotational speed TGNCcomf and high pressure calculated rotational speed TGNChp as the target rotational speed TGNC of the compressor 2, and sets the rotational speed NC of the compressor 2 to Control.
As described above, when the rotational speed limit control is being executed, the high-pressure calculated rotational speed TGNChp is reduced. Therefore, during the rotational speed limiting control, the limited high-pressure calculated rotational speed TGNChp and the upper limit rotational speed TGNCcomf The smaller value is determined as the target rotational speed TGNC of the compressor 2.
(6-5-2) Control of the heat medium circulation circuit 23 in the comfort priority mode
Next, the controller 32 determines in step S18 in FIG. 7 whether or not a failure has occurred due to a failure in the heat pump (indicated by HP in FIG. 7) comprising the refrigerant circuit R of the vehicle air conditioner 1, and the failure is determined. If (N), the heat pump (compressor 2) is stopped in step S22, and the base value Qahtr of the required capacity TGQhtr of the heat medium circulation circuit 23 is set as the required capacity TGQ in step S23. If the failure is not determined in step S18 and is normal (Y), the process proceeds to step S19 to determine whether or not the operation mode of the vehicle air conditioner 1 is the current heating mode. If it transfers to another operation mode and it is heating mode (Y), it will progress to step S20.
In step S20, the controller 32 determines the required capacity TGQ (kW), which is the heating capacity of the radiator 4 required by using the above-described formulas (II) and (III), and the heating actually generated by the radiator 4. The HP actual capacity Qhp (kW), which is the capacity, is calculated. Further, the controller 32 calculates the difference ΔQhp between the required capacity TGQ and the HP actual capacity Qhp using the above-described equation (V).
Next, the controller 32 performs stop determination of the heat pump (compressor 2) due to frosting of the outdoor heat exchanger 7 in step S21 as in step S4 of FIG. 4, and the degree of frosting becomes a predetermined value or more. (Y, HP stop), it progresses to step S22 and a heat pump (compressor 2 of the refrigerant circuit R) is stopped. On the other hand, when it is not determined in step S21 that the heat pump (compressor 2) is stopped (N, HP operation), the controller 32 proceeds to step S25 and determines whether or not a predetermined time has elapsed since the activation of the heating mode.
If the present time is the initial start of the heating mode and before a predetermined time has elapsed since the start, the process proceeds to step S26, and is the rotation speed limitation control (limitation by the suction refrigerant temperature Ts. Ts limitation) currently being executed? Judge whether or not. If the current rotational speed limit control is being executed (Ts is being limited), the process proceeds to step S27, where the maximum rotational speed NCmax is set as the actual rotational speed NC of the compressor 2 at the present time (NCmax = actual NC). That is, at this time, since the rotational speed limit control is performed, the actual rotational speed NC of the compressor 2 is decreased. Accordingly, the maximum rotational speed NCmax is also lowered accordingly. Thereafter, the controller 32 proceeds to step S28.
On the other hand, if the current rotation speed limit control is not being executed in step S26, the controller 32 proceeds to step S30 and sets the maximum rotation speed NCmax to the maximum rotation speed estimated value QmaxNCTam at the time of the rotation speed limit control described above. The controller 32 also estimates the maximum value of the rotational speed NC of the compressor 2 limited by the rotational speed limiting control by deriving the maximum rotational speed estimated value QmaxNCTam from the graph of FIG. , NCmax is set to a maximum rotational speed estimated value QmaxNCTam at the time of the rotational speed limiting control (NCmax = Ts limited rotational speed estimated value QmaxNCTam). That is, as described above, the maximum rotational speed NCmax is lowered so that the rotational speed restriction control may be performed thereafter.
After the maximum rotational speed NCmax of the compressor 2 is set to the actual rotational speed NC or the maximum rotational speed estimated value QmaxNCTam during the rotational speed limit control in the steps S27 and S30, the controller 32 proceeds to step S28. In step S28, the maximum rotation speed NCmax set in step S27 or step S30 is used to calculate the HP maximum capacity estimated value Qmax that is the estimated value of the maximum heating capacity of the radiator 4 from the above-described equation (VII). To do. Further, the difference ΔQmax (= TGQ−Qmax) between the required capacity TGQ and the HP maximum capacity estimated value Qmax is also calculated using the above-described formula (VIII).
In this case as well, NCmax is a value that takes into account the rotational speed limit control in step S27 and step S30 described above, and therefore the HP maximum capacity estimated value Qmax calculated in step S28 also decreases in NCmax by the rotational speed limit control. Minutes get smaller. Further, the difference ΔQmax between the required capacity TGQ and the HP maximum capacity estimated value Qmax also increases when Qmax is lowered in consideration of the rotational speed limit control.
Next, proceeding to step S29, the base value Qahtr of the required capacity TGQhtr of the heat medium circulation circuit 23 is set to ΔQmax. Next, proceeding to step S24, the controller 32 calculates the required capacity TGQhtr of the heat medium circulation circuit 23. In step S24, the controller 32 calculates the required capacity TGQhtr of the heat medium circulation circuit 23 using the following formula (XII).
TGQhtr = Qahtr / Φ (XII)
That is, since Qahtr = ΔQmax in step S29, the controller 32 sets the required capacity TGQhtr of the heat medium circulation circuit 23 to ΔQmax / Φ in step S24, and controls the energization of the heat medium heating electric heater 35 based on the required capacity TGQhtr. To do. Also in this case, the difference ΔQmax is a value that takes into account the rotational speed limit control. When Qmax is low, the difference ΔQmax is increased, and thus ΔQmax / Φ that is the required capacity TGQhtr of the heat medium circulation circuit 23 is also obtained. As the temperature increases, the amount of heat generated by the heat medium heating electric heater 35 also increases.
On the other hand, after the initial startup period of the heating mode has elapsed, the controller 32 proceeds from step S25 to step S31 and sets the base value Qahtr of the required capacity TGQhtr of the heat medium circulation circuit 23 to ΔQhp. Next, proceeding to step S24, the controller 32 calculates the required capacity TGQhtr of the heat medium circulation circuit 23. In step S24, the controller 32 calculates the required capacity TGQhtr of the heat medium circuit 23 using the above-described equation (XII). That is, since Qahtr = ΔQhp in step S31, the controller 32 sets the required capacity TGQhtr of the heat medium circulation circuit 23 to ΔQhp / Φ in step S24, and controls the energization of the heat medium heating electric heater 35 based on the required capacity TGQhtr. To do.
On the other hand, when the heat pump (compressor 2) is stopped in step S22, the controller 32 proceeds to step S23 to set the base value Qahtr of the required capacity TGQhtr of the heat medium circulation circuit 23 as the required capacity TGQ, and proceeds to step S24. The required capacity TGQhtr of the circulation circuit 23 is calculated. That is, since Qahtr = required capacity TGQ in step S23, the controller 32 sets the required capacity TGQhtr of the heat medium circulation circuit 23 to TGQ / Φ in step S24, and the energization of the heat medium heating electric heater 35 is performed based on the required capacity TGQhtr. To control.
If the calculated required capacity TGQhtr in step S24 is smaller than a predetermined value (for example, 100 W), the controller 32 has little change due to heating by the heat medium circulation circuit 23 (heat medium heating electric heater 35) (mostly meanings). The heat medium circulation circuit 23 is stopped (the heat medium heating electric heater 35 and the circulation pump 30 are de-energized).
In the embodiment, the controller 32 has two types of modes, the energy saving priority mode and the comfort priority mode in the heating mode. In the energy saving priority mode, the compressor 2 is set to the maximum rotation speed NCmax, and the heating capacity by the radiator 4 is insufficient. While supplemented by heating by the heat medium circulation circuit 23 (heat medium-air heat exchanger 40), in the comfort priority mode, the rotational speed NC of the compressor 2 is limited, and the heating capacity by the radiator 4 is insufficient. Since heat is supplemented by the circulation circuit 23, in the energy saving priority mode, the radiator 4 exhibits the maximum heating capacity and the shortage is supplemented by the heating by the heat medium circulation circuit 23. In the comfort priority mode, the heating capacity of the radiator 4 is limited, and the heating capacity of the heating medium circulation circuit 23 is increased to increase the heating capacity at the start-up. And early, noise also reduced, also it is possible to suppress formation of frost on the outdoor heat exchanger 7. In other words, depending on the passenger's preference and the situation of the vehicle, it is possible to switch between heating in the vehicle with priority on energy saving or heating in the vehicle with priority on comfort, reducing comfort and power consumption. It is possible to achieve both vehicle interior heating.
As described above in detail, according to the present invention, the controller 32 considers the rotational speed limit control in the energy saving priority mode and the comfort priority mode of the heating mode, and the heating medium circulation circuit 23 compensates for the shortage of the heating capacity by the radiator 4. Since the heating is complemented, the heating capacity of the radiator 4 that is reduced when the rotation speed limit control is executed is complemented without any trouble by the heating by the heat medium circulation circuit 23, thereby realizing comfortable vehicle interior heating. Will be able to.
In particular, in the embodiment, in the rotation speed limit control, the controller 32 limits the rotation speed NC of the compressor 2 so that the suction refrigerant temperature Ts of the compressor 2 does not fall below a predetermined limit target value TGTs. An HP maximum capacity estimation value Qmax that is an estimated value of the maximum heating capacity of the radiator 4 is calculated based on the maximum rotation speed NCmax, and a required capacity TGQ that is a required heating capacity of the radiator 4 and an HP maximum capacity estimation value Qmax. The compressor 2 that is calculated by calculating the difference ΔQmax = TGQ−Qmax, calculating the required capacity TGQhtr of the heat medium circulation circuit 23 from ΔQmax, and performing the heating by the heat medium circulation circuit 23 and being limited by the rotation speed limit control. Since the maximum rotational speed NCmax is changed based on the rotational speed NC of the maximum rotational speed NC, which is the basis for calculating the HP maximum capacity estimation value Qmax. max is changed based on the rotational speed NC of the compressor 2 limited by the rotational speed limiting control, and the required capacity TGQhtr of the heat medium circulation circuit 23 calculated from ΔQmax is increased by that amount, so that the heating capacity of the radiator 4 is increased. It will be possible to properly compensate for the loss of eyes.
In this case, in the embodiment, when the controller 32 is executing the rotational speed limit control, the actual rotational speed NC of the compressor 2 is set to the maximum rotational speed NCmax. The HP maximum capacity estimated value Qmax is calculated from the rotational speed NC of the compressor 2 and the required capacity TGQhtr of the heat medium circulation circuit 23 can be accurately calculated.
Further, when the rotation speed limitation control is not being executed, the controller 32 performs the maximum rotation at the rotation speed limitation control which is the maximum value of the rotation speed NC of the compressor 2 that is limited by the rotation speed limitation control based on the outside air temperature Tam. The number estimated value QmaxNCTam is estimated, and the estimated maximum rotation number estimated value QmaxNCTam is set to the maximum number of rotations NCmax, so that the heating medium circulation circuit 23 can quickly perform heating even when the rotation number limitation control is started thereafter. You will be able to complement your abilities.
In particular, in the embodiment, in the comfort priority mode, the controller 32 changes the maximum rotational speed NCmax based on the rotational speed NC of the compressor 2 that is restricted by the rotational speed restriction control in the initial stage of startup. It is possible to speed up the start-up and improve comfort.
Further, in the embodiment, after the initial startup period has elapsed, the required capacity TGQhtr of the heat medium circulation circuit 23 is set to the difference ΔQhp between the HP actual capacity Qhp that is the heating capacity actually generated by the radiator 4 and the required capacity TGQ. (= TGQ−Qhp) is obtained by performing the heating by the heat medium circulation circuit 23. Therefore, after the initial startup period has elapsed, the heating of the radiator 4 that actually occurs with respect to the required capacity TGQ. The shortage of the HP actual capacity Qhp, which is the capacity, can be accurately supplemented by heating by the heat medium circulation circuit 23, and extremely comfortable heating in the vehicle interior can be realized.
In addition, the specific method of the rotation speed limitation control described in the embodiment and the determination method of the required capacity TGQhtr of the heat medium circulation circuit 23 in consideration thereof are not limited to these, and a range that does not depart from the gist of the present invention. Various changes can be made.
In particular, in the embodiment, the rotational speed limit control is executed based on the suction refrigerant temperature Ts. However, the present invention is not limited thereto, and the rotational speed NC of the compressor 2 is limited so that the suction refrigerant pressure Ps does not fall below a predetermined limit target value. The present invention can also be applied to rotation speed control. Furthermore, the present invention is also applied to the vehicle air conditioner 1 that executes the rotational speed limit control for limiting the rotational speed NC of the compressor 2 so that the discharged refrigerant temperature Td and the discharged refrigerant pressure Pd do not rise above a predetermined limit target value. It is valid.
Further, in the embodiment, the present invention is applied to the vehicle air conditioner 1 that switches and executes each operation mode such as the heating mode, the dehumidifying heating mode, the dehumidifying cooling mode, and the cooling mode. The present invention is also effective for such a case.
Furthermore, although the auxiliary heating device is configured by the heat medium circulation circuit 23 in the embodiment, the present invention is not limited thereto, and a normal electric heater (PTC) may be provided in the air flow passage 3 to serve as the auxiliary heating device. Further, the configuration and each numerical value of the refrigerant circuit R described in the above embodiments are not limited thereto.

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

17, 20, 21, 22 Electromagnetic valve 23 Heat-medium circulation circuit (auxiliary heating device) )
30 Circulating pump 32 Controller (control means)
35 Heating medium heating electric heater (electric heater)
40 Heat medium-air heat exchanger (auxiliary heating device)
45 Suction temperature sensor R Refrigerant circuit

Claims

A compressor for compressing the refrigerant;
A radiator for heating the air supplied to the passenger compartment by dissipating the refrigerant;
An outdoor heat exchanger provided outside the passenger compartment to absorb heat from the refrigerant;
A control device,
The control device radiates the refrigerant discharged from the compressor with the radiator, depressurizes the radiated refrigerant, heats the vehicle interior by absorbing heat with the outdoor heat exchanger, and In the vehicle air conditioner for executing the rotational speed restriction control for restricting the rotational speed of the compressor and protecting the compressor,
An auxiliary heating device for heating the air supplied to the vehicle interior;
In consideration of the rotation speed limitation control, the control device supplements the heating capacity of the radiator by a heating by the auxiliary heating device.
In the rotation speed limitation control, the control device limits the rotation speed of the compressor so that the suction refrigerant temperature or the suction refrigerant pressure of the compressor does not fall below a predetermined limit target value, or the compressor Limiting the number of revolutions of the compressor so that the discharge refrigerant temperature or the discharge refrigerant pressure does not rise above a predetermined limit target value;
An HP maximum capacity estimated value Qmax, which is an estimated value of the maximum heating capacity of the radiator, is calculated based on the maximum rotational speed NCmax of the compressor,
Calculating the difference ΔQmax = TGQ−Qmax between the required capacity TGQ, which is the required heating capacity of the radiator, and the HP maximum capacity estimated value Qmax;
The required capacity TGQhtr of the auxiliary heating device is calculated from the ΔQmax, and heating by the auxiliary heating device is performed,
2. The vehicle air conditioner according to claim 1, wherein the maximum rotational speed NCmax is changed based on a rotational speed of the compressor that is restricted by the rotational speed restriction control.
3. The vehicle air conditioner according to claim 2, wherein the control device sets the actual rotational speed of the compressor to the maximum rotational speed NCmax when the rotational speed restriction control is being executed. .
The control device estimates the maximum value of the rotation speed of the compressor limited by the rotation speed limit control based on the outside air temperature when the rotation speed limit control is not being executed, and the estimated maximum The vehicle air conditioner according to claim 2 or 3, wherein the value is the maximum rotational speed NCmax.
5. The control device according to claim 2, wherein the controller changes the maximum rotational speed NCmax based on a rotational speed of the compressor that is limited by the rotational speed limiting control at an initial stage of startup. A vehicle air conditioner according to claim 1.
The control device includes:
HP actual capacity Qhp which is the heating capacity actually generated by the radiator is calculated,
A difference ΔQhp = TGQ−Qhp between the required capacity TGQ and the HP actual capacity Qhp is calculated,
6. The vehicle air conditioner according to claim 5, wherein after the initial startup period has elapsed, the required capacity TGQhtr of the auxiliary heating device is obtained from the ΔQhp, and heating by the auxiliary heating device is executed. .