JP2023000180A - Air conditioner for vehicle - Google Patents

Abstract

To provide an air conditioner for a vehicle in which energy consumption during heating is reduced by appropriately combining and actuating a plurality of heating units.SOLUTION: An air conditioner 1 for a vehicle comprises: a heat pump cycle 10 having a compressor 11 and a condenser 12; an electric heater 25; and a heating control unit 60a. The heat pump cycle 10 having the condenser 12 heats blown air that is blown into a cabin by using a cooling medium discharged from the compressor 11 as a heat source. The electric heater 25 generates heat for heating the blown air. The heating control unit 60a controls the heating capacity of the electric heater 25. A first energy consumption by the heat pump cycle 10 is less than a second energy consumption by the electric heater 25. The heating control unit 60a of the air conditioner 1 for a vehicle executes heater combination operation using the electric heater 25 in combination if the rotational frequency of the compressor 11 is a reference rotational frequency KNc or more, and the temperature of the blown air is less than a target blowout temperature TAO.SELECTED DRAWING: Figure 4

Description

TECHNICAL FIELD The present disclosure relates to a vehicle air conditioner that includes a plurality of heating units.

2. Description of the Related Art Conventionally, technologies related to vehicle air conditioners having a plurality of heating units as heat sources for heating have been developed. A technique described in Patent Document 1 is known as a vehicle air conditioner having a plurality of heating units.

In Patent Document 1, the heating unit specifically includes an indoor condenser of a heat pump cycle, a heater core using exhaust heat from the engine, and a PTC heater that generates heat when energized. Then, in the vehicle air conditioner of Patent Document 1, when the outside air temperature becomes equal to or lower than a predetermined value, an engine operation request is output and the PTC heater is energized.

JP-A-2011-5982

However, in Patent Literature 1, the PTC heater, which consumes a large amount of energy, is operated simply by judging the outside air temperature. For this reason, even under operating conditions in which sufficient heating can be achieved by the heat pump cycle alone, which has good energy efficiency, the PTC heater may be activated, and electricity may be wasted. .

In view of the above points, an object of the present disclosure is to provide a vehicle air conditioner that reduces energy consumption during heating by appropriately combining and operating a plurality of heating units.

A vehicle air conditioner according to an aspect of the present disclosure includes a heat pump cycle (10) having a compressor (11) and first heating units (12, 20), a second heating unit (25), and a heating control unit ( 60a) and The compressor compresses and discharges refrigerant. The first heating unit heats the air that is blown into the vehicle interior using the refrigerant discharged from the compressor as a heat source. The second heating section generates heat for heating the blown air. The heating control section controls the heating capacity of the second heating section.

In the vehicle air conditioner, the first energy consumption is less than the second energy consumption. The first energy consumption amount is the energy consumption amount required for raising the temperature of the air blown at a predetermined volume in the first heating unit to a predetermined temperature. The second energy consumption amount is the energy consumption amount required for raising the temperature of the blown air of a predetermined volume in the second heating unit to a predetermined temperature.

The heating control unit exerts a heating capability on the second heating unit when the rotation speed of the compressor is equal to or higher than a predetermined reference rotation speed and the temperature of the blown air is lower than the target air temperature (TAO). Let

In the vehicle air conditioner, the fact that the rotation speed of the compressor is equal to or higher than the predetermined reference rotation speed means that the first heating unit is exhibiting the capability corresponding to the reference rotation speed as the ability to heat the blown air. means Also, the fact that the temperature of the blast air is less than the target blowout temperature indicates that the heating of the blast air is insufficient for the target blowout temperature.

In other words, according to the vehicle air conditioner, the first heating unit, which consumes a small amount of energy, heats the blown air. The second heating unit is caused to exert its heating ability. Therefore, the second heating section, which consumes a large amount of energy, can heat the blown air under appropriate conditions. Energy consumption can be reduced.

It should be noted that the reference numerals in parentheses of each means described in this column and claims indicate the correspondence with specific means described in the embodiments described later.

BRIEF DESCRIPTION OF THE DRAWINGS It is a whole block diagram of the vehicle air conditioner which concerns on one Embodiment. 1 is a block diagram showing a control system of a vehicle air conditioner according to one embodiment; FIG. 1 is an overall configuration diagram showing operation in a heating mode in a vehicle air conditioner of one embodiment; FIG. It is a flow chart about heat pump cycle in heating mode etc., and operation of an electric heater. FIG. 4 is an explanatory diagram showing an example of operating states of a compressor and an electric heater during heating;

An embodiment will be described below with reference to the drawings. A vehicle air conditioner 1 shown in FIG. 1 is an air conditioner that adjusts a vehicle interior space (in other words, a space to be air-conditioned) to an appropriate temperature. The vehicle air conditioner 1 has a heat pump cycle 10 .

The heat pump cycle 10 is mounted on an electric vehicle, a hybrid vehicle, or the like. An electric vehicle is a vehicle that obtains a driving force for running the vehicle from an electric motor for running. A hybrid vehicle is a vehicle that obtains a driving force for driving the vehicle from an engine (in other words, an internal combustion engine) and an electric motor for driving.

The heat pump cycle 10 is a vapor compression refrigerator comprising a compressor 11, a condenser 12, a first expansion valve 13, an air side evaporator 14, a constant pressure valve 15, a second expansion valve 16 and a cooling water side evaporator 17. . In the heat pump cycle 10 of the present embodiment, a Freon-based refrigerant is used as a refrigerant, and constitutes a subcritical refrigeration cycle in which the pressure of the refrigerant on the high-pressure side does not exceed the critical pressure of the refrigerant.

In the refrigerant flow of the heat pump cycle 10, the first expansion valve 13, the air-side evaporator 14, the constant pressure valve 15, the second expansion valve 16, and the coolant-side evaporator 17 are arranged in parallel. That is, the heat pump cycle 10 is formed with a first refrigerant circuit and a second refrigerant circuit.

In the first refrigerant circulation circuit, the refrigerant circulates through the compressor 11, the condenser 12, the first expansion valve 13, the air-side evaporator 14, the constant pressure valve 15, and the compressor 11 in this order. In the second refrigerant circulation circuit, the refrigerant circulates through the compressor 11, the condenser 12, the second expansion valve 16, and the coolant-side evaporator 17 in this order.

Next, each component in the heat pump cycle 10 will be described. The compressor 11 is an electric compressor driven by electric power supplied from a battery, and sucks, compresses, and discharges the refrigerant of the heat pump cycle 10 . The electric motor of compressor 11 is controlled by control device 60 shown in FIG. Compressor 11 may be a variable displacement compressor driven by a belt.

The condenser 12 is a high pressure side heat exchanger that exchanges heat between the high pressure side refrigerant discharged from the compressor 11 and the cooling water of the high temperature cooling water circuit 20 . The condenser 12 is a heat radiating section that heats the cooling water by heat-exchanging the refrigerant discharged from the compressor 11 and the cooling water. Therefore, the heat pump cycle 10 corresponds to an example of the first heating section.

In the case of an electric vehicle, the compressor 11 and condenser 12 are arranged in the motor room of the vehicle. A motor room is a space in which an electric motor for traveling is accommodated. In the case of a hybrid vehicle, the compressor 11 and condenser 12 are arranged in the engine room of the vehicle. An engine room is a space in which an engine is housed.

As shown in FIG. 1, the condenser 12 has a condensation section 12a, a receiver 12b and a supercooling section 12c. In the condenser 12, the refrigerant flows through the condensing section 12a, the receiver 12b, and the supercooling section 12c in that order.

The condensation part 12 a condenses the high pressure side refrigerant by exchanging heat between the high pressure side refrigerant discharged from the compressor 11 and the cooling water of the high temperature cooling water circuit 20 . The receiver 12b is a gas-liquid separation unit that separates the gas-liquid of the high-pressure refrigerant that has flowed out of the condenser 12, causes the separated liquid-phase refrigerant to flow downstream, and stores surplus refrigerant in the cycle. The supercooling unit 12c performs heat exchange between the liquid-phase refrigerant flowing out of the receiver 12b and the cooling water of the high-temperature cooling water circuit 20, thereby supercooling the liquid-phase refrigerant.

The first expansion valve 13 is a first decompression unit that decompresses and expands the liquid-phase refrigerant that has flowed out of the condenser 12 . The first expansion valve 13 is an electric expansion valve. An electric expansion valve is an electric variable throttle mechanism that includes a valve body that can change the degree of opening of the throttle and an electric actuator that changes the degree of opening of the valve body.

The first expansion valve 13 is a refrigerant flow switching unit that switches between a state in which the refrigerant flows in the air-side evaporator 14 and a state in which the refrigerant does not flow. The operation of the first expansion valve 13 is controlled by a control signal output from the control device 60 .

The first expansion valve 13 may be a mechanical thermal expansion valve. If the first expansion valve 13 is a mechanical thermal expansion valve, an on-off valve that opens and closes the refrigerant flow path on the first expansion valve 13 side must be provided separately from the first expansion valve 13 .

The air-side evaporator 14 is an evaporator that exchanges heat between the refrigerant flowing out of the first expansion valve 13 and the air blown into the vehicle interior to evaporate the refrigerant. In the air-side evaporator 14, the refrigerant absorbs heat from the air blown into the vehicle interior. The air-side evaporator 14 is an air cooler that cools the air blown into the vehicle interior.

The constant pressure valve 15 is a pressure adjusting unit that maintains the pressure of the refrigerant on the outlet side of the air-side evaporator 14 at a predetermined value. The constant pressure valve 15 is composed of a mechanical variable throttle mechanism. When the pressure of the refrigerant on the outlet side of the air-side evaporator 14 falls below a predetermined value, the constant pressure valve 15 reduces the passage area (i.e., throttle opening) of the refrigerant passage and reduces the pressure of the refrigerant on the outlet side of the air-side evaporator 14. exceeds a predetermined value, the passage area of the refrigerant passage is increased. The gas-phase refrigerant pressure-regulated by the constant pressure valve 15 is sucked into the compressor 11 and compressed.

In addition, when the flow rate of the circulating refrigerant circulating in the heat pump cycle 10 is small, etc., instead of the constant pressure valve 15, a fixed restrictor composed of an orifice, a capillary tube, or the like may be employed. Also, although the constant pressure valve 15 has a mechanical variable throttle mechanism, the present invention is not limited to this aspect. An electric constant pressure valve can also be used as the constant pressure valve 15 .

The second expansion valve 16 is a second decompression unit that decompresses and expands the liquid-phase refrigerant that has flowed out of the condenser 12 . The second expansion valve 16 is an electric expansion valve. An electric expansion valve is an electric variable throttle mechanism that includes a valve body that can change the degree of opening of the throttle and an electric actuator that changes the degree of opening of the valve body. The second expansion valve 16 can fully close the refrigerant passage.

The second expansion valve 16 is a refrigerant flow switching unit that switches between a state in which the refrigerant flows in the coolant-side evaporator 17 and a state in which the refrigerant does not flow. The operation of the second expansion valve 16 is controlled by a control signal output from the control device 60 .

As with the first expansion valve 13 , a mechanical thermal expansion valve may be employed as the second expansion valve 16 . Also in this case, an on-off valve for opening and closing the refrigerant flow path on the side of the second expansion valve 16 must be provided separately from the second expansion valve 16 .

The coolant-side evaporator 17 is an evaporator that exchanges heat between the refrigerant flowing out of the second expansion valve 16 and the coolant in the low-temperature cooling water circuit 30 to evaporate the refrigerant. In the coolant-side evaporator 17 , the refrigerant absorbs heat from the coolant in the low-temperature coolant circuit 30 . The coolant-side evaporator 17 is a heat medium cooler that cools the coolant in the low-temperature coolant circuit 30 . The vapor phase refrigerant evaporated in the cooling water side evaporator 17 is sucked into the compressor 11 and compressed.

Next, the configuration of the high-temperature cooling water circuit 20 in the vehicle air conditioner 1 will be described. The high-temperature cooling water circuit 20 is a circulation circuit in which cooling water circulates, and can be called a high-temperature heat medium circuit in which a high-temperature heat medium circulates. The cooling water of the high temperature cooling water circuit 20 is a fluid as a heat medium and a high temperature heat medium. In this embodiment, as the cooling water for the high-temperature cooling water circuit 20, a liquid containing at least ethylene glycol, dimethylpolysiloxane, or a nanofluid, or an antifreeze liquid is used.

As shown in FIG. 1, the high-temperature cooling water circuit 20 includes a condenser 12, a high-temperature side pump 21, a heater core 22, a first reserve tank 24, and an electric heater 25. As shown in FIG. The high-temperature cooling water circuit 20 is a heating circuit that circulates cooling water to the heater core 22 .

The high temperature side pump 21 is a heat medium pump that sucks and discharges cooling water. The high temperature side pump 21 is an electric pump. The high temperature side pump 21 is an electric pump with a constant discharge flow rate, but the high temperature side pump 21 may be an electric pump with a variable discharge flow rate.

A discharge port of the high temperature side pump 21 is connected to the inlet side of the cooling water flow path in the condenser 12 . The direction of flow of cooling water in condenser 12 is opposite to the direction of flow of refrigerant in condenser 12 . That is, in the condenser 12, the cooling water flows through the supercooling section 12c and the condensing section 12a in that order.

The heater core 22 is an air heating unit that heats the air that is blown into the vehicle interior by exchanging heat between the cooling water of the high-temperature cooling water circuit 20 and the air that is blown into the vehicle interior. In the heater core 22, the cooling water radiates heat to the air blown into the vehicle interior. The heater core 22 is a heat utilization section that utilizes the heat of the cooling water heated by the condenser 12 . The heater core 22 is arranged between the on-off valve 26 and the first reserve tank 24 in the high-temperature cooling water circuit 20 .

A first reserve tank 24 is connected to the coolant outlet side of the heater core 22 . The first reserve tank 24 is a storage section that stores excess cooling water. By storing excess cooling water in the first reserve tank 24, it is possible to suppress a decrease in the amount of cooling water circulating through the high-temperature cooling water circuit 20. FIG. Further, the first reserve tank 24 has a gas-liquid separation function of separating air bubbles mixed in the cooling water from the cooling water.

The first reserve tank 24 is a closed reserve tank or an open-air reserve tank. The closed reserve tank is a reserve tank that sets the pressure of the liquid surface of the stored cooling water to a predetermined pressure. The atmosphere open type reserve tank is a reserve tank in which the pressure at the liquid surface of the stored cooling water is brought to the atmospheric pressure. A suction port of the high temperature side pump 21 is connected to the cooling water outlet side of the first reserve tank 24 .

As shown in FIG. 1, an electric heater 25 is connected to the outlet side of the cooling water flow path in the condenser 12 . The electric heater 25 is a heat source device that generates Joule heat when electric power is supplied from a battery to heat the cooling water. The electric heater 25 corresponds to an example of the second heating section. The electric heater 25 heats the coolant in the high-temperature coolant circuit 20 . Electric heater 25 is controlled by controller 60 .

An on-off valve 26 is arranged downstream of the electric heater 25 with respect to the flow of cooling water in the high-temperature cooling water circuit 20 . The on-off valve 26 is a switching unit that switches the flow of cooling water in the high-temperature cooling water circuit 20 . The on-off valve 26 opens and closes the coolant flow path between the electric heater 25 and the heater core 22 to adjust the degree of opening of the coolant flow path.

Next, the configuration of the low-temperature cooling water circuit 30 in the vehicle air conditioner 1 will be described. The low-temperature cooling water circuit 30 is a low-temperature heat medium circuit in which a low-temperature heat medium circulates, and is a second circulation circuit in which cooling water circulates. The cooling water of the low temperature cooling water circuit 30 is a fluid as a heat medium and a low temperature heat medium. In this embodiment, as the cooling water for the low-temperature cooling water circuit 30, a liquid containing at least ethylene glycol, dimethylpolysiloxane, or a nanofluid, or an antifreeze liquid is used.

As shown in FIG. 1 , the low-temperature cooling water circuit 30 includes a low-temperature side pump 31 , a cooling water-side evaporator 17 , a second reserve tank 32 and a radiator 33 . The low temperature side pump 31 is a heat medium pump that draws in and discharges cooling water from the low temperature cooling water circuit 30 . The low temperature side pump 31 is an electric pump. The outlet side of the low temperature side pump 31 is connected to the inlet side of the cooling water flow path in the cooling water side evaporator 17 .

A radiator 33 is connected to the outlet side of the coolant flow path in the coolant-side evaporator 17 . The radiator 33 is a radiator that exchanges heat between the cooling water in the low-temperature cooling water circuit 30 and the outside air, and radiates heat from the cooling water to the outside air. The radiator 33 is arranged at the forefront of the vehicle. Therefore, when the vehicle is running, the radiator 33 can be exposed to running wind.

Also, an outdoor blower 34 for blowing outside air to the radiator 33 is arranged. The outdoor blower 34 is an electric blower whose fan is driven by an electric motor. Operation of the outdoor fan 34 is controlled by the controller 60 .

A second reserve tank 32 is connected to the outlet side of the cooling water flow path in the radiator 33 . The second reserve tank 32 has the same structure and function as the first reserve tank 24 .

Next, the configuration of the indoor air conditioning unit 50 in the vehicle air conditioner 1 will be described. As shown in FIG. 1 , the indoor air conditioning unit 50 is configured by housing the air-side evaporator 14 , the heater core 22 and the like inside an air conditioning casing 51 . The indoor air conditioning unit 50 is arranged inside a not-shown instrument panel in the front part of the passenger compartment.

The air conditioning casing 51 is an air passage forming member that forms an air passage. The heater core 22 is arranged downstream of the air-side evaporator 14 in the air passage in the air conditioning casing 51 . An inside/outside air switching box 52 and an indoor fan 53 are arranged in the air conditioning casing 51 .

The inside/outside air switching box 52 is an inside/outside air switching unit that switches between introducing inside air and outside air into the air passage in the air conditioning casing 51 . The indoor air blower 53 draws in the inside air and the outside air introduced into the air passage in the air conditioning casing 51 through the inside/outside air switching box 52 and blows the air. The operation of the indoor fan 53 is controlled by the controller 60 .

An air mix door 54 is arranged between the air-side evaporator 14 and the heater core 22 in the air passage in the air conditioning casing 51 . The air mix door 54 adjusts the air volume ratio between the cold air flowing into the heater core 22 and the cold air flowing through the cold air bypass passage 55 among the cold air that has passed through the air-side evaporator 14 .

The cold air bypass passage 55 is an air passage through which cold air that has passed through the air-side evaporator 14 flows while bypassing the heater core 22 .

The air mix door 54 is a rotary door having a rotating shaft rotatably supported with respect to the air conditioning casing 51 and a door base plate portion coupled to the rotating shaft. A rotation shaft of the air mix door 54 is driven by a servomotor 56 . The operation of the air mix door servo motor 56 is controlled by a controller 60 .

By adjusting the opening position of the air mix door 54, the temperature of the air-conditioned air blown out from the air-conditioning casing 51 into the passenger compartment can be adjusted to a desired temperature. The conditioned air whose temperature has been adjusted by the air mix door 54 is blown into the vehicle interior through an outlet 57 formed in the air conditioning casing 51 .

The air mix door 54 may be a slide door that slides in a direction substantially perpendicular to the air flow. The sliding door may be a plate-shaped door made of a rigid body. A film door formed of a flexible film material may be used.

Next, a control system of the vehicle air conditioner 1 will be described with reference to FIG. The vehicle air conditioner 1 has a control device 60, and the control device 60 is composed of a well-known microcomputer including a CPU, ROM, RAM, etc. and its peripheral circuits. The control device 60 performs various calculations and processes based on control programs stored in the ROM.

As shown in FIG. 2, various devices to be controlled are connected to the output side of the control device 60 . The control device 60 controls the operation of various devices to be controlled. Various devices to be controlled include a compressor 11, a first expansion valve 13, a second expansion valve 16, a high temperature side pump 21, an electric heater 25, an on-off valve 26, a low temperature side pump 31, an outdoor fan 34, an indoor fan 53, an air A servo motor 56 for the mix door is included.

Various control sensors are connected to the input side of the control device 60 . The various control sensor groups include an inside air temperature sensor 61, an outside air temperature sensor 62, a solar radiation sensor 63, a high temperature cooling water temperature sensor 64, a radiator temperature sensor 65, an outlet temperature sensor 66, and the like. The inside air temperature sensor 61 detects the vehicle interior temperature Tr. An outside air temperature sensor 62 detects outside air temperature Tam. The solar radiation sensor 63 detects the solar radiation Ts inside the vehicle compartment.

A high temperature cooling water temperature sensor 64 detects the temperature TWH of the cooling water in the high temperature cooling water circuit 20 . For example, the high temperature cooling water temperature sensor 64 detects the temperature of the cooling water flowing out from the electric heater 25 . A radiator temperature sensor 65 detects the temperature TWR of the cooling water flowing into the radiator 33 . The blowout temperature sensor 66 is a blowout temperature detection unit that detects the temperature TAV of the blown air blown out from the mixing space into the passenger compartment.

An operation panel 70 having a plurality of operation switches is connected to the input side of the control device 60 . A plurality of operation switches arranged on the operation panel 70 are operated by the passenger and are used for inputting the passenger's instructions. Operation signals from various operation switches are input to the control device 60 . The operation panel 70 is arranged near the instrument panel in the front part of the passenger compartment.

Various operation switches include an auto switch, an air conditioner switch, a temperature setting switch, an instant heating switch, and the like. The auto switch is a switch for setting and canceling the automatic control operation of the vehicle air conditioner 1 . The air conditioner switch is a switch for setting whether or not to cool the air in the indoor air conditioning unit 50 . A temperature setting switch is a switch for setting a preset temperature in the vehicle compartment. The immediate heating switch is a switch for rapidly heating the vehicle interior by executing the vehicle interior heating operation prior to other operation modes in the vehicle air conditioner 1 . An operation panel 70 having an instant heating switch corresponds to an example of a heating operation section.

The control device 60 of the present embodiment is configured integrally with a control section that controls various controlled devices connected to the output side thereof. The configuration (hardware and software) that controls the operation of each controlled device in the control device 60 is a control unit that controls the operation of each controlled device.

For example, in the control device 60, a heating control section 60a is configured to appropriately use heating by the heat pump cycle 10 and heating by the electric heater 25 in an operation mode involving heating of blown air.

Further, in the control device 60, the configuration for requesting heating by the electric heater 25 when predetermined heat generation conditions are satisfied in the operation mode involving heating of the blown air constitutes a heat generation requesting section 60b.

In the control device 60, a configuration for determining whether or not a predetermined heat generation condition is satisfied in the operation mode involving heating of the blown air constitutes a heat generation condition determination section 60c. The heat generation condition determination unit 60c determines that the heat generation condition is satisfied, for example, when the immediate heating switch is turned on or when a predetermined operation is performed with the temperature setting switch.

In the control device 60, a target temperature setting unit 60d is configured to set a set temperature (for example, a target blowout temperature TAO) in accordance with the operation of a temperature setting switch during air conditioning operation of the vehicle air conditioner 1.

Next, the operation of the vehicle air conditioner 1 will be described. Below, the operation of the control device 60 when the auto switch of the operation panel 70 is turned on by the passenger will be described. When the air conditioner switch on the operation panel 70 is turned on by the passenger, the operation mode is switched based on the target blowout temperature TAO and the like. Operation modes include at least a cooling mode, a dehumidifying heating mode, and a heating mode.

The target blowout temperature TAO is the target temperature of the blown air blown into the vehicle interior. The control device 60 calculates the target outlet temperature TAO based on the following formula.

TAO = Kset x Tset - Kr x Tr - Kam x Tam - Ks x Ts + C
In this formula, Tset is the vehicle interior set temperature set by the temperature setting switch on the operation panel 70, and Tr is the inside temperature detected by the inside air temperature sensor 61. FIG. Tam is the outside air temperature detected by the outside air temperature sensor 62 and Ts is the amount of solar radiation detected by the solar radiation amount sensor 63 . Kset, Kr, Kam, and Ks are control gains, and C is a correction constant.

The control device 60 switches to the cooling mode in the low temperature range of the target blowing temperature TAO, and switches to the dehumidifying heating mode in the high temperature range of the target blowing temperature TAO.

In the dehumidification heating mode, the air-side evaporator 14 cools and dehumidifies the air blown into the vehicle interior, and the heater core 22 heats the air cooled and dehumidified by the air-side evaporator 14 to dehumidify and heat the vehicle interior.

The control device 60 switches to the heating mode when the air conditioner switch on the operation panel 70 is turned off by the passenger and the target blowout temperature TAO is in the high temperature range.

In the heating mode, the vehicle interior is heated by heating the air blown into the vehicle interior with the heater core 22 without cooling and dehumidifying the air with the air-side evaporator 14 .

Next, operations of the vehicle air conditioner 1 in the dehumidifying heating mode and the heating mode will be described. In the dehumidifying and heating mode and the heating mode, the control device 60 determines the operation states of various control devices connected to the control device 60 based on the target blowout temperature TAO, detection signals from the above-described sensor group, and the like.

(1) Dehumidification and Heating Mode In the dehumidification and heating mode, the heater core 22 heats the blown air dehumidified by the air-side evaporator 14 to air-condition the vehicle interior, which is the space to be air-conditioned. Therefore, the dehumidification heating mode is one of the operation modes accompanied by heating of the blown air.

In the dehumidifying heating mode, the controller 60 operates the compressor 11 , the high temperature side pump 21 and the low temperature side pump 31 . In the dehumidifying heating mode, the control device 60 opens the first expansion valve 13 and the second expansion valve 16 with the throttle opening. In the dehumidification heating mode, the controller 60 opens the on-off valve 26 .

In the heat pump cycle 10 in the dehumidification/heating mode, the refrigerant circulates through the compressor 11, the condenser 12, the first expansion valve 13, the air-side evaporator 14, the constant pressure valve 15, and the compressor 11 in this order. At the same time, the refrigerant circulates through the compressor 11, the condenser 12, the second expansion valve 16, the coolant-side evaporator 17, and the compressor 11 in this order.

As a result, the cooling water in the high-temperature cooling water circuit 20 is heated by the heat of the high-pressure refrigerant flowing through the condenser 12 . Also, the low-pressure refrigerant decompressed by the first expansion valve 13 flows into the air-side evaporator 14, absorbs heat from the air blown into the vehicle interior, and evaporates. Therefore, the air blown into the passenger compartment is cooled and dehumidified. The low-pressure refrigerant decompressed by the second expansion valve 16 flows into the cooling water side evaporator 17, absorbs heat from the cooling water in the low-temperature cooling water circuit 30, and evaporates. Therefore, the cooling water in the low temperature cooling water circuit 30 is cooled.

In the high-temperature cooling water circuit 20 in the dehumidifying heating mode, the cooling water circulates through the high-temperature side pump 21, the condenser 12, the electric heater 25, the opening/closing valve 26, the heater core 22, and the first reserve tank 24 in this order. Therefore, the cooling water in the high-temperature cooling water circuit 20 is in a state in which it can be heated by the high-pressure refrigerant in the condenser 12 and by the electric heater 25 .

The control signal output to the servomotor of the air mix door 54 is set so that the air mix door 54 fully opens the air passage of the heater core 22 and the entire flow rate of the air that has passed through the air-side evaporator 14 passes through the heater core 22 . is determined by

As a result, the heater core 22 radiates heat from the cooling water in the high-temperature cooling water circuit 20 to the air blown into the vehicle interior. Therefore, the air that has been cooled and dehumidified by the air-side evaporator 14 is heated by the heater core 22 and blown into the passenger compartment.

In the low-temperature cooling water circuit 30 in the dehumidifying and heating mode, the cooling water flows and circulates through the low-temperature side pump 31, the cooling water-side evaporator 17, the radiator 33, the second reserve tank 32, and the low-temperature side pump 31 in this order. Therefore, the cooling water of the low-temperature cooling water circuit 30 absorbs heat from the outside air in the radiator 33 .

Thus, in the dehumidification heating mode, the heat of the high-pressure refrigerant discharged from the compressor 11 and the heat generated by the electric heater 25 can be used to heat the coolant in the high-temperature coolant circuit 20 . The heat of the cooling water in the high-temperature cooling water circuit 20 is radiated to the air by the heater core 22, so that the air that has been cooled and dehumidified by the air-side evaporator 14 can be heated. As a result, dehumidification and heating of the passenger compartment can be achieved.

(2) Heating Mode In the heating mode, the heater core 22 heats the blown air that has passed through the air-side evaporator 14 to heat the vehicle interior, which is the space to be air-conditioned. Therefore, the heating mode is one of the operating modes involving heating of the blast air.

In the heating mode, the controller 60 operates the compressor 11 , the high temperature side pump 21 and the low temperature side pump 31 . In the heating mode, the control device 60 closes the first expansion valve 13 and opens the second expansion valve 16 at the throttle opening. In the heating mode, the controller 60 opens the on-off valve 26 .

In the heat pump cycle 10 in the heating mode, as shown in FIG. 3, the refrigerant circulates through the compressor 11, the condenser 12, the second expansion valve 16, the coolant-side evaporator 17, and the compressor 11 in this order.

As a result, the cooling water in the high-temperature cooling water circuit 20 is heated by the heat of the high-pressure refrigerant flowing through the condenser 12 . The low-pressure refrigerant decompressed by the second expansion valve 16 flows into the cooling water side evaporator 17, absorbs heat from the cooling water in the low-temperature cooling water circuit 30, and evaporates. Thereby, the cooling water in the low-temperature cooling water circuit 30 is cooled.

In the heating mode, since the first expansion valve 13 is closed, no refrigerant flows to the air-side evaporator 14 . Therefore, in the air-side evaporator 14, the blown air is not cooled and dehumidified.

In the high-temperature cooling water circuit 20 in the heating mode, as shown in FIG. flows and circulates in the order of Therefore, the cooling water in the high-temperature cooling water circuit 20 is in a state in which it can be heated by the high-pressure refrigerant in the condenser 12 and by the electric heater 25 .

The control signal output to the servomotor of the air mix door 54 is set so that the air mix door 54 fully opens the air passage of the heater core 22 and the entire flow rate of the air that has passed through the air-side evaporator 14 passes through the heater core 22 . is determined by

As a result, the heater core 22 radiates heat from the cooling water in the high-temperature cooling water circuit 20 to the air blown into the vehicle interior. Therefore, the air that has passed through the air-side evaporator 14 is heated by the heater core 22 and blown into the passenger compartment.

In the low temperature cooling water circuit 30 in the heating mode, the cooling water circulates through the low temperature side pump 31, the cooling water side evaporator 17, the radiator 33, the second reserve tank 32, and the low temperature side pump 31 in this order. Therefore, the cooling water of the low-temperature cooling water circuit 30 absorbs heat from the outside air in the radiator 33 .

Thus, in the heating mode, the heat of the high-pressure refrigerant discharged from the compressor 11 and the heat generated by the electric heater 25 can be used to heat the coolant in the high-temperature coolant circuit 20 . The heat of the cooling water in the high-temperature cooling water circuit 20 is radiated to the air by the heater core 22, so that the air that has passed through the air-side evaporator 14 can be heated. As a result, dehumidification and heating of the passenger compartment can be achieved.

As described above, in the operation mode involving heating of the blown air in the vehicle air conditioner 1, the heat pump cycle 10 and the electric heater 25 can be used as heat sources for the blown air. The heating capacity of the heat pump cycle 10 and the heating capacity of the electric heater 25 will be described.

Here, in the heat pump cycle 10, the amount of energy consumption required to raise the temperature of the air having a predetermined volume to a predetermined temperature is referred to as the first energy consumption amount. The amount of energy consumption necessary for raising the temperature of the air having a predetermined volume by the electric heater 25 to a predetermined temperature is referred to as the second energy consumption amount.

As described above, the electric heater 25 generates Joule heat when supplied with electric power to heat the cooling water. less than In other words, the heat pump cycle 10 can heat the blast air more efficiently than the electric heater 25 in terms of energy consumption.

Therefore, in the dehumidification heating mode and the heating mode, the heat pump cycle 10 is used as much as possible as a heating source of the blown air, and the frequency of use of the electric heater 25 is reduced, thereby maintaining comfort by heating the blown air. , the energy consumption can be kept low.

In the vehicle air conditioner 1 according to the present embodiment, the control program shown in FIG. 4 is executed in order to properly use the heat pump cycle 10 and the electric heater 25 properly in the operation mode involving heating of the blown air.

This control process is executed as a subroutine of a control program executed by the control device 60 when the operation mode of the vehicle air conditioner 1 is switched to an operation mode involving heating of blown air. Further, when the operation mode is switched to the operation mode involving heating of the blown air, the control device 60 sets the heat pump cycle 10, the high-temperature cooling water circuit 20, and the low-temperature cooling water circuit 30 to the above-described heating mode or dehumidifying heating mode. control, and the operation of the heat pump cycle 10 is started.

When execution of the control program shown in FIG. 4 is started with the start of the heating mode or the dehumidifying/heating mode, first, in step S1, it is determined whether or not the heater heat generation condition is satisfied. Here, the heater heat generation condition means a condition under which it is considered desirable to use the electric heater 25 when heating the blown air. The heater heat generation condition corresponds to an example of the heat generation condition.

If it is determined that the heater heat generation condition is satisfied, the process proceeds to step S6. If it is determined that the heater heat generation condition is not satisfied, the process proceeds to step S2. One of the heater heat generation conditions is when the immediate heating switch on the operation panel 70 is turned on. In this case, it is desirable to use both the heat pump cycle 10 and the electric heater 25 as heating heat sources because it is required to heat the vehicle interior rapidly.

Further, as one of the heater heat generation conditions, the case where the temperature setting switch on the operation panel 70 is operated to set the set temperature (for example, the target blowout temperature TAO) higher than a predetermined reference temperature can be mentioned. . If the preset temperature is set higher than the predetermined reference temperature by the passenger's operation, there is a high possibility that the passenger feels cold. This is because, in order to increase the comfort in the passenger compartment, it is necessary to heat the passenger compartment as quickly as possible, and it is desirable to use both the heat pump cycle 10 and the electric heater 25 as heating heat sources.

In step S2, it is determined whether or not the rotation speed of the compressor 11 in the operation mode involving heating of the blown air is equal to or higher than a predetermined reference rotation speed KNc. The reference rotation speed KNc indicates the rotation speed of the compressor 11 when the heating capacity of the heat pump cycle 10 is fully exhibited. That is, in step S2, it is determined whether or not the heating capacity of the heat pump cycle 10 is fully exhibited.

If the rotation speed of the compressor 11 is equal to or higher than the reference rotation speed KNc, the process proceeds to step S3. On the other hand, if the rotation speed of the compressor 11 is less than the reference rotation speed KNc, it means that the heat pump cycle 10 still has a margin in the heating capacity, so the process proceeds to step S5.

In step S3, it is determined whether or not a predetermined time has passed since the compressor 11 reached or exceeded the reference rotational speed KNc. That is, the standby time is provided to determine whether or not the heating capacity of the heat pump cycle 10 can be used to realize the heating operation corresponding to the set temperature. The process waits in step S3 until a predetermined time elapses, and when the predetermined time elapses, the process proceeds to step S4.

In step S4, it is determined whether or not the blowing air temperature TAV detected by the blowing temperature sensor 66 is equal to or higher than the target blowing temperature TAO. If the blown-out air temperature TAV is equal to or higher than the target blown-out temperature TAO, the current heating capacity of the heat pump cycle 10 can achieve heating corresponding to the target blown-out temperature TAO, so the process proceeds to step S5. On the other hand, if the blown air temperature TAV is less than the target blown temperature TAO, the heating capacity of the heat pump cycle 10 cannot realize heating corresponding to the target blown temperature TAO, so the process proceeds to step S6.

In step S5, the heat pump independent operation is continued in the operation modes involving heating of the blown air (that is, the heating mode and the dehumidifying heating mode). In other words, the air conditioning operation is performed using the heat pump cycle 10 as a heat source for the blown air without the electric heater 25 generating heat.

In the heat pump independent operation, the electric heater 25 does not generate heat, but the heating capacity of the heat pump cycle 10 is appropriately adjusted. For example, the heating capacity of the heat pump cycle 10 is controlled by controlling the refrigerant discharge capacity of the compressor 11, the throttle opening degrees of the first expansion valve 13 and the second expansion valve 16, and the like.

Therefore, in the heat pump independent operation when the process proceeds from step S2, the refrigerant discharge capacity of the compressor 11 has a margin, so that the heating capacity of the heat pump cycle 10 is controlled to be increased. On the other hand, in the heat pump independent operation from step S4, operation control of the compressor 11, the first expansion valve 13, the second expansion valve 16, etc. is performed so that the blown air temperature TAV approaches the target blown air temperature TAO. .

In step S6, a combined heater operation using both the heat pump cycle 10 and the electric heater 25 as heat sources is performed for the operation mode involving heating of the blown air. In the heater combined operation when it is determined in step S1 that the heater heat generation condition is satisfied, the heat generation control of the electric heater 25 is performed regardless of the magnitude of the heating capacity of the heat pump cycle 10 .

On the other hand, in the combined heater operation after step S4, the heating capacity of the heat pump cycle 10 and the heating capacity of the electric heater 25 are controlled so that the heating state corresponding to the target blowing temperature TAO is maximized in energy efficiency. be. For example, the heating capacity of the heat pump cycle 10 is maximized, and the electric heater 25 is made to generate the amount of heat that is insufficient for the target blowout temperature TAO in that state. In this case, the heat pump cycle 10, which is a heat source with good energy efficiency, is fully utilized, and the electric heater 25 is used as an auxiliary heat source, so that the amount of energy consumed in the operation mode involving heating of the blown air can be kept low. can.

Then, according to the control program shown in FIG. 4, when the rotation speed of the compressor 11 becomes equal to or higher than the reference rotation speed KNc, after waiting for the lapse of a predetermined time (step S3), the blown-out air temperature TAV reaches the target blow-out temperature. If the temperature is lower than the temperature TAO, the combined heater operation is executed. As shown in FIG. 5, since the rotation speed of the compressor 11 has reached the reference rotation speed KNc, the necessity of heating the blast air using the electric heater 25 is fully confirmed. Therefore, it is possible to appropriately cope with the increase in energy consumption due to the combined operation with the heater.

As described above, the vehicle air conditioner 1 according to one embodiment includes the heat pump cycle 10 having the condenser 12 as the first heating section and the electric heater 25 as the second heating section. Therefore, the vehicle air conditioner 1 can selectively use the heat pump cycle 10 and the high-temperature cooling water circuit 20, which consume different amounts of energy, as heating sources for the blown air in an operation mode involving heating of the blown air, or can appropriately combine them. can.

As shown in FIG. 4, in steps S2 and S4, the vehicular air-conditioning system 1 operates when the rotational speed of the compressor 11 is equal to or higher than the reference rotational speed KNc and the blown air temperature TAV is less than the target blown air temperature TAO. In some cases, the heater combined operation is used to heat the blast air. That is, the vehicle air conditioner 1 heats the blown air in the heat pump cycle 10, which consumes a small amount of energy. Demonstrate heating capacity.

Therefore, according to the vehicle air conditioner 1, the electric heater 25, which consumes a large amount of energy, heats the blown air in an appropriate condition. can reduce energy consumption during heating.

Further, as shown in step S1 in FIG. 4, the vehicle air conditioner 1 heats the blown air by the heater combined operation when a predetermined heater heat generation condition is satisfied. For this reason, according to the vehicle air conditioner 1, when it is desired to rapidly increase the temperature of the blown air, the heat pump cycle 10 and the electric heater 25 can be used in combination to rapidly The temperature of the blast air can be raised.

One of the heater heat generation conditions is when the immediate heating switch on the operation panel 70 is turned on. The instant heating switch is a switch operated by the user when requesting rapid vehicle interior heating.

Accordingly, the vehicle air conditioner 1 executes the combined heater operation using the heat pump cycle 10 and the electric heater 25 in accordance with the intention input based on the user's operation. That is, the vehicle air conditioner 1 can heat the blown air using the heat pump cycle 10 and the electric heater 25 in an appropriate manner according to the user's intention.

Alternatively, as one of the heater heat generation conditions, a case where a set temperature (for example, a target blowout temperature TAO) is set higher than a predetermined reference temperature by operating a temperature setting switch on the operation panel 70 can be mentioned. . A situation in which the set temperature is set higher than the reference temperature by operating the temperature setting switch indicates a situation in which the user feels cold and wants heating by heating the blown air.

Accordingly, the vehicle air conditioner 1 executes the combined heater operation using the heat pump cycle 10 and the electric heater 25 in accordance with the intention input based on the user's operation. That is, the vehicle air conditioner 1 can heat the blown air using the heat pump cycle 10 and the electric heater 25 in an appropriate manner according to the user's intention.

Then, as shown in FIGS. 4 and 5, when the rotation speed of the compressor 11 becomes equal to or higher than the reference rotation speed KNc, the vehicle air conditioner 1 waits for the lapse of a predetermined time, and then executes the combined heater operation. do. By waiting for a predetermined time from the time when the rotation speed of the compressor 11 becomes equal to or higher than the reference rotation speed KNc, it is possible to reliably determine that the heating capacity of the heat pump cycle 10 is fully exhibited. As a result, the vehicle air conditioner 1 can improve the determination accuracy regarding the proper use of the heat pump independent operation and the heater combined operation, and can appropriately use the heat pump cycle 10 and the electric heater 25 properly as heating sources for the blown air. can.

(Other embodiments)
The present invention is not limited to the above-described embodiments, and can be variously modified as follows without departing from the scope of the present invention. Moreover, the means disclosed in each of the above embodiments may be appropriately combined within the practicable range.

(1) In the above-described embodiments, cooling water is used as the heat medium, but various media such as oil may be used as the heat medium. A nanofluid may be used as a heat carrier. A nanofluid is a fluid mixed with nanoparticles having a particle size on the order of nanometers.

(2) In addition, in the heat pump cycle 10 according to the above-described embodiment, a freon-based refrigerant is used as a refrigerant, but the type of refrigerant is not limited to this, and natural refrigerants such as carbon dioxide and hydrocarbon-based refrigerants are used. A refrigerant or the like may be used.

Further, the heat pump cycle 10 of the above-described embodiment constitutes a subcritical refrigeration cycle in which the high-pressure side refrigerant pressure does not exceed the critical pressure of the refrigerant, but a supercritical refrigeration cycle in which the high-pressure side refrigerant pressure exceeds the critical pressure of the refrigerant. may constitute

(3) In the above-described embodiment, the heat pump cycle 10 as the first heating section and the electric heater 25 as the second heating section are provided as heat sources for the blown air, but the present invention is limited to this aspect. is not. If the number of heat sources for blowing air is two or more, more heat sources may be arranged. For example, an engine for heating the delivery air can be employed as the heat source.

(4) In the above-described embodiment, when heating the blown air, heating is performed by the heat pump cycle 10 and the electric heater 25 through the cooling water of the high-temperature cooling water circuit 20, but this aspect is not limited to That is, it is possible to employ a configuration in which the heat pump cycle 10 and the electric heater 25 directly heat the blown air.

In this case, as the condenser 12 of the heat pump cycle 10 , an indoor condenser that radiates the heat of the high-pressure refrigerant discharged from the compressor 11 to the blown air may be arranged inside the air conditioning casing 51 . An electric heater 25 is arranged upstream or downstream of the indoor condenser in the indoor air conditioning unit 50 . By configuring in this way, it is possible to realize a configuration in which the blown air is directly heated by the first heating section and the second heating section.

(5) And the heater heat generation conditions are not limited to those given in the above-described embodiments. Various conditions can be adopted as the heater heat generation condition as long as the content indicates a situation in which it is desired to rapidly heat the air blown into the air-conditioned space.

For example, a case may be employed in which the set temperature (target blowout temperature TAO) is changed from the immediately preceding set temperature to be higher than a predetermined reference temperature difference by operating a temperature setting switch on the operation panel 70. . The situation in which the operation is performed in this case also indicates that the user is feeling cold and is requesting heating by heating the blown air, so the same effect as in the case of the heater heat generation condition according to the above-described embodiment is exhibited. can be made

1 Vehicle Air Conditioner 10 Heat Pump Cycle 11 Compressor 12 Condenser 20 High Temperature Cooling Water Circuit 25 Electric Heater 60 Control Device 60a Heating Control Unit

Claims (5)

A heat pump cycle ( 10) and
a second heating unit (25) that generates heat for heating the blown air;
A vehicle air conditioner comprising a heating control section (60a) that controls the heating capacity of the second heating section,
The first energy consumption required to raise the temperature of the blown air of a predetermined air volume predetermined by the first heating unit to a predetermined predetermined temperature is the less than the second energy consumption required to raise the temperature of the blast air to the predetermined temperature,
The heating control unit controls the second heating unit to A vehicle air conditioner that demonstrates its heating capacity. a heat generation requesting unit (60b) that requests heat generation by the second heating unit when a predetermined heat generation condition is satisfied;
2. The vehicle air conditioner according to claim 1, wherein the heating control section causes the second heating section to exhibit heating capacity when the heat generation requesting section requests the second heating section to generate heat. A heat generation operation unit (70) that requests heat generation of the second heating unit by user operation,
3. The vehicle air conditioner according to claim 2, wherein the heat generation condition is established when the heat generation operation section requests the second heating section to generate heat. A target temperature setting unit (60d) for setting a target temperature in the vehicle interior by a user's operation,
4. The vehicle air conditioner according to claim 2, wherein the heat generation condition is established when the target temperature set by the target temperature setting unit is higher than a predetermined reference temperature. 2. When the rotation speed of the compressor reaches a predetermined reference rotation speed or higher, the heating control unit causes the second heating unit to generate heat after waiting for a predetermined standby time to elapse. 5. The vehicle air conditioner according to any one of 1 to 4.

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