JP2021142871A - Vehicle air conditioner and operation mode switching control method - Google Patents

Abstract

To prevent frequent switching between an operation mode in which refrigerant does not flow through an evaporator and an operation mode in which the refrigerant flows through the evaporator, and in order to reduce a switching frequency, eliminate the need for providing a regulating valve in a path between the outlet side of the evaporator and a compressor.SOLUTION: In vehicle air conditioners equipped with refrigeration cycles, a compressor 11, a first heat exchanger 2, a first inflator 12, a passenger compartment outdoor heat exchanger 4, a second inflator 14, and a second heat exchanger 3 are connected in this order in a loop. The connection is made via a first bypass flow path 16 provided with a first refrigerant control unit 15 between the first heat exchanger 2 and the first inflator 12 and between the passenger compartment outdoor heat exchanger 4 and the second inflator 14. A backflow blocking unit 13 is provided on the downstream side of the passenger compartment outdoor heat exchanger 4 and on the upstream side of the merging portion with the first bypass flow path. The connection is made via a second bypass flow path 18 provided with the second refrigerant control unit 17 between the passenger compartment outdoor heat exchanger 4 and the backflow blocking unit 13 and between the second heat exchanger 3 and the compressor 11. A heat storage material TS is provided in the second heat exchanger 3.SELECTED DRAWING: Figure 1

Description

The present invention relates to a vehicle air conditioner and an operation mode switching method for reducing the generation of noise due to frequent switching of operation modes, and particularly to an operation mode in which a refrigerant flows through a heat absorption heat exchanger arranged in the air conditioning unit. The present invention relates to a technique for suppressing frequent switching between an operation mode in which a refrigerant does not flow.

Conventionally, there is known an air conditioner for a vehicle that not only cools or heats the interior of a vehicle with a heat pump type refrigeration cycle but also enables dehumidifying operation.
For example, in Patent Document 1 (Japanese Patent Laid-Open No. 2014-094671), a first heat exchanger (radiator 4), which is arranged in an air conditioning unit and whose ventilation amount is adjusted by a damper (air mix damper 28), is described in Patent Document 1 (Japanese Patent Laid-Open No. 2014-094671). ), The first expansion device (outdoor expansion valve 6), the vehicle outdoor heat exchanger (outdoor heat exchanger 7) capable of exchanging heat with the outside air, and the second expansion device (indoor expansion valve 8). At least in this order, the second heat exchanger (heat exchanger 9) arranged in the air conditioning unit and arranged upstream of the first heat exchanger (radiator 4) in the air flow direction in the air conditioning unit. A refrigeration cycle connected in a loop is provided, and the refrigeration cycle includes a refrigerant flow path between the first heat exchanger (radiator 4) and the first expansion device (outdoor expansion valve 6), and the outside of the vehicle interior. A first bypass provided with a first refrigerant control unit (electromagnetic valve 22) for the refrigerant flow path between the heat exchanger (outdoor heat exchanger 7) and the second expansion device (indoor expansion valve 8). Of the refrigerant flow paths connected via the flow path (fluident pipe 13F) and between the vehicle outdoor heat exchanger (outdoor heat exchanger 7) and the second expansion device (indoor expansion valve 8), the first The second refrigerant is formed between the refrigerant flow path on the upstream side of the confluence with the bypass flow path (fluid pipe 13F) of No. 1 and the refrigerant flow path between the second heat exchanger (heat exchanger 9) and the compressor. A heat pump cycle connected via a second bypass flow path (fluid pipe 13D) provided with a control unit (electromagnetic valve 21) is disclosed.

Then, the carrier mode is switched according to the outside temperature, and especially in an environment where the outside temperature is around 0 degrees, the refrigerant discharged from the compressor is first discharged with a threshold value provided in the vicinity as a boundary. The heat is dissipated by the heat exchanger (heat exchanger 4) of the above, and the radiated refrigerant is branched. In the dehumidifying and heating operation mode in which heat is absorbed by the outdoor heat exchanger, the refrigerant discharged from the compressor is radiated by the first heat exchanger, and the radiated refrigerant is not branched, but after decompression, the vehicle outdoor heat exchanger The point of switching to the heating operation mode in which heat is absorbed is disclosed.

However, when the operation mode in which the refrigerant is not passed through the heat absorber arranged in the air conditioning unit and the operation mode in which the refrigerant is passed through the heat absorber are frequently switched at a predetermined threshold value, the operating noise of the electromagnetic valve is switched. Not only that, since the refrigerant flows into the second heat (heat absorber 9) to which the refrigerant is not supplied at once via the second expansion device (indoor expansion valve 8), sudden abnormal noise is frequently generated. There is an inconvenience.

In order to deal with such inconvenience, the refrigerant evaporation pressure (refrigerant evaporation temperature) in the indoor evaporator is maintained above the predetermined reference evaporation pressure (reference evaporation temperature) between the outlet of the evaporator and the compressor. A refrigeration cycle device has been proposed in which an evaporation pressure adjusting valve is provided so that frost formation (frost) of an indoor evaporator can be suppressed without frequently switching the operation mode (see Patent Document 2).

Japanese Unexamined Patent Publication No. 2014-094671 Japanese Unexamined Patent Publication No. 2016-11760

However, when such a refrigeration cycle is adopted, it is necessary to pass the refrigerant in the cycle through the evaporation pressure adjusting valve in all the operation modes except the heating operation mode, so that the evaporation pressure adjusting valve is used in the cycle. The inconvenience of increasing passage resistance may occur.

The present invention has been made in view of the above circumstances, and prevents frequent switching between an operation mode in which the refrigerant does not flow through the evaporator in the air conditioning unit and an operation mode in which the refrigerant flows, and suppresses the frequency of switching the operation mode. Therefore, the main task is to provide an air conditioner for vehicles and an operation mode switching control method that do not require the arrangement of a regulating valve in the path between the outlet side of the evaporator and the compressor.

In order to achieve the above object, the vehicle air conditioner according to the present invention is a first heat that is arranged in a compressor (11) and an air conditioner unit (1) and whose ventilation amount is adjusted by a damper (10). The exchanger (2) and the second exchanger (2) arranged in the air conditioning unit (1) and arranged upstream of the first heat exchanger (2) in the air conditioning unit (1). 3), the vehicle interior heat exchanger (4) capable of exchanging heat with the outside air, the first expansion device (12) capable of narrowing and opening and closing the refrigerant flow path, and the refrigerant flow path. And a second inflator (14) that can be closed,
The compressor (11), the first heat exchanger (2), the first inflator (12), the outdoor heat exchanger (4), the second inflator (14), and the above. Connect the second heat exchanger (3) in a loop at least in this order.
Between the refrigerant flow path between the first heat exchanger (2) and the first expansion device (12) and between the vehicle interior heat exchanger (4) and the second expansion device (14). Is connected to the refrigerant flow path of the above via a first bypass flow path (16) that can be opened and closed by the first refrigerant control unit (15).
Of the refrigerant flow paths between the vehicle interior heat exchanger (4) and the second expansion device (14), on the upstream side of the merging portion (A) with the first bypass flow path (16). A backflow blocking portion (13) that blocks the flow of the refrigerant from the merging portion (A) to the upstream side is provided, and the refrigerant flow between the vehicle interior heat exchanger (4) and the backflow blocking portion (13). A second bypass flow path (18) provided with a second refrigerant control unit (17) for the refrigerant flow path between the path, the second heat exchanger (3), and the compressor (11). Has a refrigeration cycle (100) connected via
The second heat exchanger (3) is characterized in that a heat storage material (TS) is provided.

Therefore, in the vehicle air conditioner provided with the above-mentioned heat pump cycle, since the heat storage material is provided in the second heat exchanger, the operation mode in which the refrigerant is passed through the second heat exchanger and the second heat exchanger It is possible to avoid the inconvenience of frequently switching to the operation mode in which the refrigerant does not flow through the air, and it is possible to suppress the generation of noise due to the frequent switching of the operation mode as much as possible.

In particular, such a vehicle air conditioner includes a refrigeration cycle (100) and a control means (50) for switching and controlling an operation mode of the refrigeration cycle (100), and the control means (50)
The refrigerant discharged from the compressor (11) is dissipated by the first heat exchanger (2), and the dissipated refrigerant is depressurized by the first expansion device (12), and then the outside heat of the passenger compartment is generated. Heating that absorbs heat in the exchanger (4) and then returns it to the compressor (11) via the second bypass flow path (18) without allowing the second heat exchanger (3) to flow through. Driving and
The refrigerant discharged from the compressor (11) is radiated by the first heat exchanger (2), and the radiated refrigerant is branched, while passing through the first bypass flow path (16). The heat is absorbed through the second heat exchanger (3) after being depressurized by the second inflator (14), and on the other hand, the heat is exchanged outside the passenger compartment after being decompressed by the first inflator (12). A dehumidifying and heating operation in which heat is absorbed by the vessel (4) and returned to the compressor (11) via the second bypass flow path (18).
It is effective to avoid the inconvenience that the switching between the heating operation and the dehumidifying heating operation is frequently performed when the switching is possible.

That is, it is possible to avoid a state in which the heating operation and the dehumidifying heating operation are frequently switched, and the operation mode in which the refrigerant is not circulated in the second heat exchanger is changed to the operation mode in which the refrigerant is circulated in the second heat exchanger. It is possible to suppress the number of times of noise (abnormal noise caused by the sudden flow of the refrigerant) generated at the time of switching.

It is necessary to switch the operation mode in order to avoid freezing of the second heat exchanger and secure the cooling capacity while suppressing frequent switching between the heating operation and the dehumidifying heating operation.
Therefore, for example, a state detection sensor (54) for detecting the temperature state of the second heat exchanger (3) is provided, and the control means (50) uses the state detection sensor (54) to detect the second. When it is estimated or detected that the temperature of the heat exchanger (3) of the above heat exchanger (3) has fallen below the phase change temperature (T0) of the heat storage material (TS), or when the wetness of the refrigerant flowing out from the second heat exchanger When it is detected that the degree exceeds a predetermined value (S1) larger than zero, the operation mode may be switched from the dehumidifying / heating operation to the heating operation.

According to such a configuration, the heat storage material becomes lower than the phase change temperature, or the wetness of the refrigerant flowing out from the second heat exchanger rises above the predetermined value (S1). Even when the risk of freezing of the second heat exchanger is detected and a heat storage material is provided to avoid frequent switching of the operation mode, switching of the operation mode is indispensable to avoid freezing of the second heat exchanger. In that case, it is possible to switch the operation mode to maintain a comfortable air-conditioned state.

Further, in the control means (50), the temperature of the second heat exchanger (3) is a predetermined value higher than the phase change temperature (T0) of the heat storage material (TS) by the state detection sensor (54). When it is estimated or detected that the temperature exceeds (T2), the operation mode may be switched from the heating operation to the dehumidifying heating operation.

According to such a configuration, the necessity of recovering the cooling capacity of the second heat exchanger is detected by the heat storage material becoming higher than the phase change temperature, and the heat storage material is provided to frequently operate the operation mode. If it is essential to switch the operation mode in order to secure the cooling capacity of the second heat exchanger even when avoiding such switching, it is possible to switch the operation mode and maintain a comfortable air-conditioned state. ..

The state detection sensor (54) may be an air temperature sensor (54a) that detects the temperature of the air on the downstream side of the second heat exchanger (3).
Further, the state detection sensor (54) may be a contact type temperature sensor (54b.54c) that directly detects the temperature of the second heat exchanger or the heat storage material.
Further, the state detection sensor (54) may be a temperature / pressure sensor (54d) that detects the wetness of the refrigerant flowing out from the second heat exchanger (3).

In addition to reducing the noise by reducing the number of times the operation mode is switched, it is desirable to reduce the noise itself generated when the operation mode is switched.
Therefore, the control means (50) switches between the heating operation and the dehumidifying heating operation.
With the second refrigerant control unit (17) maintained in the open state,
Switching from the dehumidifying heating operation to the heating operation by switching the second expansion device (14) from the throttle state to the closed state, and switching the second expansion device (14) from the closed state to the throttle state. It is preferable to switch from the heating operation to the dehumidifying heating operation.

According to such a configuration, the operation mode is changed to the heating operation mode by switching the second expansion device between the closed state and the throttle state while the second refrigerant control unit (17) is maintained in the open state. Since the operation can be switched between the dehumidifying and heating operation, it is possible to suppress the generation of noise due to the high-pressure refrigerant flowing into the second expansion device at once. As a result, in addition to reducing the noise caused by frequent switching of the operation mode, it is possible to reduce the noise caused by the switching of the operation mode itself.

Further, in order to achieve the above object, the operation mode switching control method according to the present invention is an operation mode switching control method for switching between the heating operation and the dehumidifying heating operation.
When it is estimated or detected that the temperature of the second heat exchanger (3) is lower than the phase change temperature (T0) of the heat storage material (TS) or a predetermined value (T1) lower than that, or When it is detected that the wetness of the refrigerant flowing out of the second heat exchanger exceeds a predetermined value (S1) larger than zero, the dehumidifying and heating operation is switched to the heating operation.
When it is estimated or detected that the temperature of the second heat exchanger (3) exceeds the phase change temperature (T0) of the heat storage material (TS) or a predetermined value (T2) higher than that. It is characterized by switching from the heating operation to the dehumidifying heating operation.

If such a control method is adopted, even when a heat storage material is provided to suppress frequent switching between the heating operation and the dehumidifying heating operation, in order to avoid freezing of the second heat exchanger, and in order to prevent the second heat exchanger from freezing. When it is necessary to switch the operation mode in order to secure the cooling capacity of the heat exchanger, the operation mode is switched.

Further, in the operation mode switching control method for switching between the heating operation and the dehumidifying heating operation, the second refrigerant control unit (17) is maintained in the open state, and the second expansion device is switched from the throttled state to the closed state. It is preferable to switch from the dehumidifying and heating operation to the heating operation, and to switch from the heating operation to the dehumidifying and heating operation by switching the second expansion device from the closed state to the throttle state.
According to such a configuration, it is possible to reduce the noise caused by the switching of the operation mode itself in addition to the noise caused by the frequent switching of the operation mode.

As described above, according to the present invention, the compressor, the first heat exchanger in the air conditioning unit, the first inflator, the vehicle interior heat exchanger capable of exchanging heat with the outside air, and the second inflator. , And the second heat exchanger arranged in the air conditioning unit and located upstream of the first heat exchanger are connected in a loop at least in this order, and the first heat exchanger and the first heat exchanger are connected. The refrigerant flow path between the expansion device and the refrigerant flow path between the vehicle interior heat exchanger and the second expansion device are opened and closed by the first refrigerant control unit via the first bypass flow path. A backflow blocking section is provided on the downstream side of the vehicle interior heat exchanger and upstream of the confluence with the first bypass flow path, and the refrigerant flow path between the vehicle interior heat exchanger and the backflow blocking section is provided. In a vehicle air conditioner having a refrigeration cycle in which the refrigerant flow path between the second heat exchanger and the compressor is connected via a second bypass flow path provided with a second refrigerant control unit. Since the heat storage material is provided in the second heat exchanger, it is frequently switched between the operation mode in which the refrigerant flows through the second heat exchanger and the operation mode in which the refrigerant does not flow through the second heat exchanger. It is possible to avoid the inconvenience that occurs, and it is possible to suppress the generation of noise associated with frequent switching of the operation mode as much as possible.
In addition, since it is not necessary to arrange a regulating valve in the path between the outlet side of the evaporator and the compressor in order to reduce the frequency of switching the operation mode, the inconvenience of increasing the passage resistance in the cycle is eliminated, and the cycle configuration is configured. It is also possible to avoid complications.

FIG. 1 shows a configuration example of a vehicle air conditioner according to the present invention, FIG. 1 (a) is an overall configuration diagram thereof, and FIG. 1 (b) shows an expansion device, a refrigerant control unit, an on-off valve, and a damper. It is a table which showed the state for each operation mode. FIG. 2 is a diagram showing each operation mode of the refrigeration cycle that can be switched according to the difference between the heat load and the target blowing temperature. The flow path through which the refrigerant is flowing is shown by a thick line, and the high-pressure flow path is shown by a thick solid line. The low pressure flow path is indicated by a thick dashed line. FIG. 3 is a diagram showing a state in which the dehumidifying / heating (Parallel) operation and the heating operation are switched between each other. FIG. 4 is a diagram showing the switching timing between the dehumidifying / heating (Parallel) operation and the heating operation. It is a figure which shows the switching state of the operation mode of this invention with respect to a temperature change. FIG. 5 is a diagram for explaining the timing of switching from the dehumidifying / heating operation of the vehicle air conditioner according to the present invention to the heating operation, and FIG. 5A is a diagram in which the temperature of the second heat exchanger is the phase change temperature of the heat storage material (a). It is a characteristic diagram explaining the case of switching from the dehumidifying heating operation to the heating operation when it is estimated or detected that the value is lower than the predetermined value (T1) which is To) or lower, and FIG. It is a characteristic diagram explaining the case of switching from the dehumidifying heating operation to the heating operation when it is detected that the wetness of the refrigerant flowing out from the heat exchanger exceeds a predetermined value (S1) larger than zero. FIG. 6 is a diagram for explaining the timing of switching from the heating operation of the vehicle air conditioner according to the present invention to the dehumidifying heating operation, and the temperature of the second heat exchanger is the phase change temperature (To) of the heat storage material or higher. It is a characteristic diagram explaining the case of switching from a heating operation to a dehumidifying heating operation when it is estimated or detected that the value exceeds a high predetermined value (T2). FIG. 7 shows that the dehumidifying heating operation is switched to the heating operation by switching the second expansion device from the throttle state to the closed state while the second refrigerant control unit is maintained in the open state, and the second expansion device is also displayed. It is a figure explaining the control which switches from a heating operation to a dehumidifying heating operation by switching from a closed state to a throttle state.

Hereinafter, embodiments of the vehicle air conditioner according to the present invention will be described with reference to the drawings.
FIG. 1 shows a vehicle air conditioner according to the present invention, wherein the vehicle air conditioner is mounted on, for example, an automobile, and the first and second heat exchangers 2 and 2 are arranged in the air conditioner unit 1. 3 and an vehicle interior heat exchanger 4 which is arranged outside the air conditioning unit 1 and can exchange heat with the outside air.

An inside / outside air switching device 6 is provided on the most upstream side of the air conditioning unit 1, and the inside air inlet 6a and the outside air inlet 6b are selectively opened by the intake door 7. The inside air or outside air selectively introduced into the air conditioning unit 1 is sucked by the rotation of the blower 8 and sent to the first and second heat exchangers 2 and 3, where the heat is exchanged to obtain a desired outlet. It is supplied to the passenger compartment from 9a to 9c.

The first heat exchanger 2 is arranged on the downstream side in the air flow direction in the air conditioning unit 1 with respect to the second heat exchanger 3, and is located on the upstream side in the air flow direction of the first heat exchanger 2. , The damper 10 is provided. The damper 10 can be changed from the position where the air volume passing through the first heat exchanger 2 is maximum (heating position: opening 100%) to the position where it is minimum (cooling position: opening 0%). By adjusting the opening degree, the ratio of the air passing through the first heat exchanger 2 and the air bypassing the first heat exchanger 2 can be adjusted.
The damper 10 is also called an air mix door. Further, in this example, the electric heat generating type heating device (PTC) 5 is arranged on the downstream side of the first heat exchanger 2 in the air conditioning unit 1.

The refrigerant inflow side 2a of the first heat exchanger 2 is connected to the discharge side α of the compressor 11, and the refrigerant outflow side 2b of the first heat exchanger 2 is the first expansion device (E-1) 12 It is connected to the inflow side 12a of. Further, the refrigerant outflow side 3b of the second heat exchanger 3 is connected to the suction side β of the compressor 11 via the accumulator 23. The first heat exchanger 2 is also called an indoor radiator or an inner capacitor.

The outflow side 12b of the first expansion device 12 is connected to the refrigerant inflow side 4a of the vehicle interior heat exchanger 4, and the refrigerant outflow side 4b of the vehicle interior heat exchanger 4 is the check valve 13 and the second check valve 13. It is connected to the refrigerant inflow side 3a of the second heat exchanger 3 via the expansion device (E-2) 14. Therefore, the compressor 11, the first heat exchanger 2, the first inflator 12, the passenger compartment outdoor heat exchanger 4, the check valve 13, the second inflator 14, the second heat exchanger 3, and the accumulator 23. , The refrigeration cycle connected in a loop in the order of the compressor 11 is formed.

Further, the refrigerant flow path between the refrigerant outflow side 2b of the first heat exchanger 2 and the inflow side 12a of the first expansion device 12, and the outflow side 13b of the check valve 13 and the second expansion device 14 The refrigerant flow path to the inflow side 14a is connected by a first bypass flow path 16 having a first refrigerant control unit (V-1) 15.

Further, the refrigerant flow path between the refrigerant outflow side 4b of the vehicle interior heat exchanger 4 and the inflow side 13a of the check valve 13, the refrigerant outflow side 3b of the second heat exchanger 3 and the inflow side 23a of the accumulator 23 The refrigerant flow path between the two is connected by a second bypass flow path 18 having a second refrigerant control unit (V-2) 17.

Here, in the above-described configuration example, the first expansion device 12 uses an electromagnetic expansion valve capable of narrowing, closing, and fully opening the refrigerant flow path by a control signal from the outside. Further, the second expansion device 14 uses an electromagnetic control valve capable of narrowing and closing the refrigerant flow path by a control signal from the outside.
The check valve 13 may be replaced with an on-off valve (V-3) 19 that opens and closes the flow path. The check valve 13 or the on-off valve (V-3) 19 constitutes a check valve.

Further, the first refrigerant control unit (V-1) 15 is composed of an on-off valve that opens and closes the first bypass flow path 16, and the second refrigerant control unit (V-2) 17 is a second. It is composed of an on-off valve that opens and closes the bypass flow path 18 of the above.

Further, as the second heat exchanger 3, one having a heat storage function is used. That is, the second heat exchanger 3 houses the heat storage material (cold storage material) TS inside, and the heat storage material TS increases the heat capacity of the second heat exchanger 3, and the second heat exchanger 3 Even if the temperature of the air passing through the heat exchanger fluctuates, the temperature of the second heat exchanger 3 does not quickly follow this, but slowly follows it.
Various modes can be considered as the heat exchanger provided with such a heat storage material TS. For example, as shown in Japanese Patent Application Laid-Open No. 2013-237387, laminated heat in which tubes and corrugated fins are alternately laminated. A exchanger may be used in which each tube is provided with a heat storage material holding portion separately from the refrigerant passage, and the heat storage material holding portion holds the heat storage material.

The operation of the first and second expansion devices 12 and 14, the opening and closing of the first and second refrigerant control units 15 and 17 and the on-off valve 19, the opening of the damper 10, and the discharge amount of the compressor 11 are controlled by means for controlling. It is controlled by a control signal from 50 (control unit 50). As the compressor 11, for example, an electric compressor is used.

The control unit 50 is known in itself and includes an input circuit including an A / D converter, a multiplexer, etc., an arithmetic processing circuit including a ROM, RAM, a CPU, etc., an output circuit including a drive circuit, etc. The outside air temperature signal from the outside air temperature sensor 51 that detects the temperature (outside air temperature), the inside air temperature signal from the inside air temperature sensor 52 that detects the vehicle interior temperature, the solar radiation amount signal from the solar radiation sensor 53 that detects the amount of solar radiation, and operation. Various signals from the operation unit that sets the mode etc. are input. Further, signals of the state detection sensors 54 (54a, 54b, 54c) for detecting the temperature state of the second heat exchanger 3 are also input to the control unit 50, and these various signals are predetermined to be predetermined. It is designed to be processed according to the program.

Here, the state detection sensor is an air temperature sensor 54a that is attached to the downstream side of the ventilation portion of the second heat exchanger 3 and detects the temperature of the air on the downstream side of the second heat exchanger 3. Even if the contact type temperature sensor 54b is in contact with the surface of the heat exchange portion of the second heat exchanger 3 and directly detects the temperature of the second heat exchanger 3, the heat storage material TS Even if the contact type temperature sensor 54c is installed on the surface or the like and directly detects the temperature of the heat storage material TS, the temperature and pressure sensor 54d that detects the wetness of the refrigerant flowing out from the second heat exchanger 3 can be used. There may be.

In this example, the switching of the operation mode of the refrigeration cycle 100 (expansion devices 12, 14, on-off valve 19, refrigerant control units 15, 17, and change of the operating state of the damper) is between heating operation and dehumidifying heating operation (Parallel). Except for switching between each other, it was set by the occupants and the status of the heat load received by the refrigeration cycle (total signal (Tm) that takes into account the temperature of the outside air, the temperature of the inside air, the amount of solar radiation, etc.). As shown in FIG. 2, the temperature is switched according to the magnitude of the difference (Tm-Tset) from the target blowing temperature (Tset) in which the desired room temperature is added.

Further, in this example, the dehumidifying operation mode is roughly divided into three modes between the cooling operation mode and the heating operation mode (see FIG. 2).
-If the heat load received by the refrigeration cycle is relatively high, the outdoor heat exchanger 4 is used as a radiator as in the cooling operation mode, and the refrigerant flows in the same manner as in the cooling operation mode (first). In order to dissipate heat in two stages using the heat exchanger 2 and the passenger compartment outdoor heat exchanger 4 as radiators, a refrigerant is flowed in series with the first heat exchanger 2 and the passenger compartment outdoor heat exchanger 4. ), Set to the dehumidifying / cooling operation mode (Series) that adjusts the temperature of the dehumidified air by adjusting the opening of the air mix door.
-If the heat load received by the refrigeration cycle is a medium heat load, only the first heat exchanger 2 is used as a radiator without using the outdoor heat exchanger 4, and the second Dehumidifying / heating operation mode (hereinafter, dehumidifying / heating operation mode) uses only the heat exchanger 3 of (Called By-Pass)).
-If the heat load received by the refrigeration cycle is even lower at medium and low heat loads, two systems that use the passenger compartment outdoor heat exchanger 4 and the second heat exchanger 3 as heat exchangers in order to increase the heat absorption capacity. Dehumidifying and heating operation mode (hereinafter, dehumidifying and heating) that forms the flow of Set to the operation mode (called Parallel).

(About each operation mode)
In order to obtain each of the above operation modes, an expansion device (first expansion device (E-1) 12, second expansion device (E-2) 14), on-off valve (first refrigerant control unit 15, first The on-off valve 19) of No. 3, the second refrigerant control unit 17, and the damper 10 are set by the control unit 50 as follows.
In each operation mode, the blower 8 rotates according to the instruction from the control unit 50, the air that has passed through the inside / outside air switching device 6 is sent to the second heat exchanger 3, and then the first heat exchanger 2 Flow towards.

First, when the operation mode is set to the cooling operation mode, the control unit 50 fully opens the first expansion device (E-1) 12 and the second expansion device (E-1) 12 as shown in FIG. 1 (b). Squeeze the inflator (E-2) 14. Further, when the first and second refrigerant control units 15 and 17 are closed and the check valve 13 is replaced by the on-off valve 19, the on-off valve 19 is opened and the damper 10 is placed in the cooling position (opening 0%). (Position of, full cool position).

Then, as shown in FIG. 2, the compressed refrigerant discharged from the compressor 11 passes through the first heat exchanger 2 without radiating heat because there is no air passing through the first heat exchanger 2, and further expands to the first. Enter the vehicle interior heat exchanger 4 via the device 12. At this time, since the first expansion device 12 is in the fully open state, the high-temperature and high-pressure refrigerant discharged from the compressor 11 flows into the vehicle interior heat exchanger 4 and dissipates heat in the vehicle interior heat exchanger (). Condensed liquefaction). After that, the refrigerant radiated by the vehicle interior heat exchanger reaches the second expansion device 14 via the check valve 13 (or the on-off valve 19), is depressurized by the second expansion device 14, and is second. It enters the heat exchanger 3 of the above, and after being endothermic (evaporated and vaporized) there, it is returned to the compressor 11 via the accumulator 23.
Therefore, the air sent from the upstream side of the air conditioning unit 1 is cooled by the second heat exchanger 3, bypasses the first heat exchanger 2, and is supplied to the vehicle interior as it is as cold air.

When the operation mode is set to the dehumidifying / cooling operation mode (Series), the control unit 50 sets the position of the damper 10 and the first expansion device (E-1) as shown in FIG. 1 (b). Except for 12, the second expansion device (E-2), the refrigerant control unit, and the on-off valve are set in the same manner as in the cooling operation mode. That is, the first inflator (E-1) 12 is slightly squeezed, and the second inflator (E-2) 14 is squeezed. Further, when the first and second refrigerant control units 15 and 17 are closed and the check valve 13 is replaced by the on-off valve 19, the on-off valve 19 is opened. Then, the opening degree of the damper 10 is set to an arbitrary intermediate position.

Then, as shown in FIG. 2, the compressed refrigerant discharged from the compressor 11 is dissipated when passing through the first heat exchanger 2, and further, heat exchange outside the vehicle interior via the first expansion device 12. Enter vessel 4. At this time, since the first expansion device 12 is in a slightly squeezed state, it is slightly decompressed and expanded here to enter the vehicle interior heat exchanger 4, but heat is dissipated (condensed) by this vehicle interior heat exchanger. .. Further, since the first expansion device 12 is in a slightly throttled state, the pressure of the refrigerant in the first heat exchanger 2 is higher than in the fully opened state, and the heat dissipation force in the first heat exchanger 2 is increased. can do. After that, the refrigerant radiated by the vehicle interior heat exchanger reaches the second expansion device 14 via the check valve 13 (or the on-off valve 19), is depressurized by the second expansion device 14, and is second. It enters the heat exchanger 3 of the above, and after being endothermic (evaporated and vaporized) there, it is returned to the compressor 11 via the accumulator 23.
Therefore, the air sent from the upstream side of the air conditioning unit 1 is dehumidified by the second heat exchanger 3, and a part of the air is heated when passing through the first heat exchanger 2, and the dry cold air is dried. It is supplied to the passenger compartment as.

Next, when the operation mode is set to the dehumidification / heating operation mode (By-Pass), the control unit 50 closes the first expansion device 12 and closes the first expansion device 12, as shown in FIG. 1 (b). When the second expansion device 14 is throttled, the first refrigerant control unit 15 is opened, the second refrigerant control unit 17 is closed, and the check valve 13 is replaced by the on-off valve 19, the on-off valve 19 is closed. , The opening degree of the damper 10 is set to an arbitrary intermediate position.

Then, the compressed refrigerant discharged from the compressor 11 is dissipated (condensed and liquefied) by the first heat exchanger 2, bypasses the vehicle interior heat exchanger 4, and flows through the first bypass flow path 16. It reaches the second expansion device 14, is decompressed by the second expansion device 14, and is supplied to the second heat exchanger 3. Then, after the heat is absorbed by the second heat exchanger 3, it is returned to the compressor 11 via the accumulator 23.
Therefore, the air sent from the upstream side of the air conditioning unit 1 is dehumidified by the second heat exchanger 3, and a part of the air is heated when passing through the first heat exchanger 2, and the temperature becomes dry. It is supplied to the passenger compartment as wind.
The heating capacity in this dehumidifying / heating operation mode (By-Pass) is smaller than that in the dehumidifying / heating operation mode (parallel) described later.

When the operation mode is set to the dehumidification / heating operation mode (parallel), the control unit 50 throttles the first and second expansion devices 12 and 14 as shown in FIG. 1 (b). When the first and second refrigerant control units 15 and 17 are opened and the check valve 13 is replaced by the on-off valve 19, the on-off valve 19 is closed and the opening degree of the damper 10 is set to an arbitrary intermediate position. ..

Then, the compressed refrigerant discharged from the compressor 11 is dissipated (condensed and liquefied) by the first heat exchanger 2, and then branched, and one of them passes through the first bypass flow path 16 and expands to the second. It reaches the device 14, where it is depressurized, absorbed (evaporated and vaporized) by the second heat exchanger 3, and then returned to the compressor 11 via the accumulator 23. At the same time, the other is decompressed by the first expansion device 12 to reach the vehicle interior heat exchanger 4, where heat is absorbed (evaporated and vaporized) and then passed through the second on-off valve 17 to pass the accumulator 23. It is returned to the compressor 11 via. Therefore, the air sent from the upstream side of the air conditioning unit 1 is dehumidified by the second heat exchanger 3, and a part of the air is heated when passing through the first heat exchanger 2, and the temperature becomes dry. It is supplied to the passenger compartment as wind.

When the operation mode is set to the heating operation mode, the control unit 50 throttles the first expansion device 12 and closes the second expansion device 14, as shown in FIG. 1 (b). Further, when the first refrigerant control unit 15 is closed, the second refrigerant control unit 17 is opened, and the check valve 13 is replaced by the on-off valve 19, the on-off valve 19 is closed and the damper 10 is placed in the heating position. Set to (100% opening position, full hot position).

Then, the compressed refrigerant discharged from the compressor 11 is dissipated (condensed and liquefied) by the first heat exchanger 2, decompressed by the first expansion device 12, and reaches the vehicle interior heat exchanger 4, where heat is absorbed. After being (evaporated and vaporized), it is returned to the compressor 11 via the accumulator 23 through the second refrigerant control unit 17.
Therefore, the air sent from the upstream side of the air conditioning unit 1 passes through the second heat exchanger 3, but is not heat exchanged, and is all guided to the first heat exchanger 2 to be heated and warm air. It is supplied to the passenger compartment as.

In the above example, the dehumidifying / heating operation mode (Parallel) and the dehumidifying / heating operation mode (By-Pass) are set as the dehumidifying / heating operation mode. The difference (Tm-Tset) between the total signal (Tm) that takes into account the temperature of the air inside the vehicle, the amount of solar radiation, etc., and the target blowout temperature (Tset) that takes into account the desired room temperature (Tset) set by the occupants. Although it is switched according to the size, only the dehumidifying / heating operation mode (Parallel) may be used as the dehumidifying / heating operation mode.

By the way, in the above configuration, in all the operation modes except the heating operation, the refrigerant is supplied to the second heat exchanger 3 to dehumidify or cool the air passing through the second heat exchanger 3. There is. On the other hand, in the heating operation, the supply of the refrigerant to the second heat exchanger 3 is stopped so that the air sucked into the air unit is heated to the maximum.

Therefore, in an environment where the heat load is small, as shown in FIG. 3, the operation mode may be switched between the heating operation and the dehumidifying heating (Parallel), but the heat load (Tm-Tset) is predetermined. When the conventional method of switching the operation mode with a threshold as a boundary is adopted, when the heat load frequently fluctuates across a predetermined threshold when switching between heating operation and dehumidifying heating (Parallel) (for example, the vehicle is in the sun and the sun). In the case of traveling alternately (see the upper part of FIG. 4), the operation mode in which the refrigerant flows through the second heat exchanger 3 and the operation mode in which the refrigerant does not flow are frequently switched. In particular, when the operation mode is switched from the heating operation to the dehumidifying heating operation, the high-pressure refrigerant flows into the second expansion device 14 at once through the first bypass flow path 16, so that sudden abnormal noise is likely to occur. If the operation mode is frequently switched due to frequent fluctuations in the heat load, such abnormal noise will also occur frequently.

In order to reduce such frequently generated noise, it is sufficient not to change the operation mode frequently according to the fluctuation of the heat load, but in such a case, the second heat exchanger 3 is used. There is a problem of freezing and a problem that the cooling capacity of the second heat exchanger 3 cannot be sufficiently secured.

In this way, when switching the operation mode between heating operation and dehumidifying heating operation (Parallel), there is a request to suppress frequent noise generation by not switching sensitively according to fluctuations in heat load. It is necessary to balance the request for avoiding the risk that the second heat exchanger 3 freezes and the risk that the cooling capacity of the second heat exchanger 3 cannot be secured (insufficient). That is, it is determined that it is really necessary to switch the operation mode after slowing down the temperature change of the second heat exchanger 3 in response to the fluctuation of the heat load so that the frequent fluctuation of the heat load can be absorbed. It is preferable to switch only when it is necessary to prevent the second heat exchanger from freezing or when it is determined that it is necessary to secure the cooling capacity of the second heat exchanger.

Therefore, in this embodiment, as described above, the heat storage material TS is provided in the second heat exchanger 3, the heat capacity of the second heat exchanger itself is increased, and the heat load is immediately changed in response to frequent fluctuations. It is prevented from following (the second heat exchanger 3 is hard to cool and hard to warm). As the heat storage material TS, a material that undergoes a phase change between the liquid phase and the solid phase is used. The phase change temperature is slightly higher than 0 ° C. (eg 3 ° C.). By changing the phase, a lot of latent heat can be accumulated or released. Therefore, the heat capacity of the second heat exchanger 3 can be further increased. Then, switching between the heating operation and the dehumidifying / heating operation (Parallel) is not performed according to a predetermined threshold value of the heat load (Tm-Tset), and the temperature of the second heat exchanger (3) is changed. Based on the detection result by the state detection sensor (54) that detects the state, it is determined that it is necessary to avoid freezing of the second heat exchanger 3, and the cooling capacity of the second heat exchanger 3 is secured. The operation mode is switched only when it is determined that it is necessary (see the lower part of FIG. 4).

That is, in switching the operation mode between the heating operation and the dehumidifying heating operation, there is no possibility that the second heat exchanger 3 freezes instead of switching the operation mode by immediately following the fluctuation of the heat load. As long as the heat absorption capacity of the second heat exchanger 3 can be secured, the operation mode is not switched even if the heat load fluctuates frequently.

Then, a specific method for switching the operation mode between the dehumidifying heating operation and the heating operation is performed as follows. That is, the control unit 50 sets the temperature of the second heat exchanger (3) to the heat storage material (TS) based on the detection signal of the state detection sensor (54) that detects the temperature state of the second heat exchanger (3). ) Was estimated or detected below the phase change temperature (To), or the wetness of the refrigerant flowing out of the second heat exchanger exceeded a predetermined value (S1) greater than zero. When is detected, the operation mode is switched from the dehumidifying heating operation to the heating operation.

In this configuration in which the heat storage material TS is provided in the second heat exchanger 3, the temperature of the heat storage material is subtracted as shown in FIG. 5A in the process of the heat storage material TS shifting from the liquid phase to the solid phase. Therefore, the temperature of the second heat exchanger and the temperature of the downstream air that has passed through the second heat exchanger become constant (the temperature that becomes constant at the time of this phase change is defined as the phase change temperature To).

Therefore, when the air temperature sensor 54a for detecting the temperature of the air on the downstream side of the second heat exchanger 3 is used as the state detection sensor 54, the heat storage material TS is transferred from the liquid phase to the solid phase. Since the temperature of the air passing through the heat exchanger 3 of 2 becomes constant, the temperature detected by the air temperature sensor 54a starts to decrease from this state, and the second air temperature detected by the air temperature sensor 54a is used. It is presumed that the temperature of the heat exchanger 3 _{is lower than the phase change temperature (T 0} ) of the heat storage material TS or a predetermined value lower than that (T1: air temperature corresponding to the freezing temperature of the heat storage material TS). There is a risk that the heat exchanger 3 of 2 will freeze.

Therefore, when the air temperature sensor 54a is used as the state detection sensor 54, the temperature of the second heat exchanger is the phase change temperature To of the heat storage material TS, or the temperature detected by the air temperature sensor 54a. When it is estimated that the temperature falls below the lower predetermined value (T1), the operation mode is switched from the dehumidifying heating operation to the heating operation to avoid freezing of the second heat exchanger 3.

Further, when the contact type temperature sensor 54b that directly detects the temperature of the second heat exchanger 3 is used as the state detection sensor 54, the heat storage material TS is second in the process of shifting from the liquid phase to the solid phase. Since the temperature of the heat exchanger 3 of the above becomes constant, the temperature detected by the contact type temperature sensor 54b begins to decrease from this state, and the temperature detected by the contact type temperature sensor 54b is used to obtain the second heat exchanger 3 from the temperature detected by the contact type temperature sensor 54b. When it is detected that the temperature of the heat storage material TS falls below the phase change temperature (T ₀ ) of the heat storage material TS or a predetermined value lower than that (T1: the temperature corresponding to the freezing temperature of the heat storage material TS), the second heat exchanger 3 may freeze.

Therefore, when a contact-type temperature sensor 54b that directly detects the temperature of the second heat exchanger 3 is used as the state detection sensor 54, the second is based on the temperature detected by the contact-type temperature sensor 54b. When it is detected that the temperature of the heat exchanger 3 falls below the phase change temperature (To) of the heat storage material TS or a predetermined value (T1) lower than that, the operation mode is switched from the dehumidifying heating operation to the heating operation. Avoid freezing of the heat exchanger 3 of 2.

Further, when the contact type temperature sensor 54c that directly detects the temperature of the heat storage material TS is used as the state detection sensor 54, the temperature of the heat storage material TS changes in the process of transition from the liquid phase to the solid phase. Since it becomes constant, the temperature detected by the contact type temperature sensor 54c begins to decrease from this state, and the temperature of the second heat exchanger 3 is the phase of the heat storage material TS from the temperature detected by the contact type temperature sensor 54c. If it is detected that the temperature falls below the change temperature (T ₀ ) or a predetermined value lower than that (T1: freezing temperature of the heat storage material TS), the second heat exchanger 3 may freeze.

Therefore, when a contact-type temperature sensor 54c that directly detects the temperature of the heat storage material TS is used as the state detection sensor 54, the second heat exchanger 3 is based on the temperature detected by the contact-type temperature sensor 54c. When it is detected that the temperature of the heat storage material TS falls below the phase change temperature (To) of the heat storage material TS or a predetermined value (T1) lower than that, the operation mode is switched from the dehumidifying heating operation to the heating operation, and the second heat exchange occurs. Avoid freezing of vessel 3.

Furthermore, when the temperature and pressure sensor 54d for detecting the wetness of the refrigerant flowing out from the second heat exchanger 3 is used as the state detection sensor 54, the phase change in which the heat storage material TS shifts from the liquid phase to the solid phase. When the temperature of the heat storage material TS begins to decrease after the temperature (To), the wetness of the refrigerant gradually increases from zero, so that the wetness of the refrigerant flowing out from the second heat exchanger 3 is predetermined to be larger than zero. If it is detected that the value (S1: the temperature corresponding to the freezing temperature of the heat storage material TS) is exceeded, the second heat exchanger 3 may freeze.

Therefore, when the temperature / pressure sensor 54d for detecting the degree of wetness is used as the state detection sensor 54, the degree of wetness detected by the temperature / pressure sensor 54d is larger than zero as shown in FIG. 5 (b). When it is detected that the value exceeds a predetermined value (S1: wetness corresponding to the freezing temperature of the heat storage material TS), the operation mode is switched from the dehumidifying heating operation to the heating operation, and the second heat exchanger 3 is frozen. To avoid.

In response to the above switching from the dehumidifying / heating operation to the heating operation, the control unit 50 determines that the temperature of the second heat exchanger 3 is the phase change temperature (To) of the heat storage material TS based on the detection signal of the state detection sensor 54. When it is estimated or detected that the temperature exceeds a predetermined value (T2) higher than that, the operation mode is switched from the heating operation to the dehumidifying heating operation.

In this configuration in which the heat storage material TS is provided in the second heat exchanger 3, the temperature of the heat storage material TS, as shown in FIG. 6, is subtracted in the process of the heat storage material TS shifting from the solid phase to the liquid phase. The temperature of the second heat exchanger 3 and the temperature of the downstream air passing through the second heat exchanger 3 become constant (the temperature that becomes constant at the time of this phase change is defined as the phase change temperature To).
Therefore, when the air temperature sensor 54a for detecting the temperature of the air on the downstream side of the second heat exchanger 3 is used as the state detection sensor 54, the heat storage material TS is transferred from the solid phase to the liquid phase. Since the temperature of the air passing through the heat exchanger 3 of 2 becomes constant, the temperature detected by the air temperature sensor 54a starts to rise from this state, and the second air temperature detected by the air temperature sensor 54a is used. If it is estimated that the temperature of the heat exchanger 3 exceeds the phase change temperature (To) of the heat storage material TS or a predetermined value (T2) higher than that, the cooling capacity of the second heat exchanger 3 cannot be secured. There is a risk.

Therefore, when the air temperature sensor 54a is used as the state detection sensor 54, the temperature of the second heat exchanger 3 is the phase change temperature (To) of the heat storage material TS from the temperature detected by the air temperature sensor 54a. Or, when it is detected that the temperature exceeds a predetermined value (T2) higher than that, the operation mode is switched from the heating operation to the dehumidifying heating operation to avoid insufficient cooling capacity of the second heat exchanger 3.

Further, when the contact type temperature sensor 54b that directly detects the temperature of the second heat exchanger 3 is used as the state detection sensor 54, the heat storage material TS is second in the process of shifting from the solid phase to the liquid phase. Since the temperature of the heat exchanger 3 of the above becomes constant, the temperature detected by the contact type temperature sensor 54b starts to rise from this state, and from the temperature detected by the contact type temperature sensor 54b, the second heat exchanger 3 If it is detected that the temperature of the heat storage material TS exceeds the phase change temperature (To) of the heat storage material TS or a predetermined value (T2) higher than that, there is a possibility that the cooling capacity of the second heat exchanger 3 cannot be secured.

Therefore, when a contact-type temperature sensor 54b that directly detects the temperature of the second heat exchanger 3 is used as the state detection sensor 54, the second is based on the temperature detected by the contact-type temperature sensor 54b. When it is detected that the temperature of the heat exchanger 3 exceeds the phase change temperature (To) of the heat storage material TS or a predetermined value (T2) higher than that, the operation mode is switched from the heating operation to the dehumidifying heating operation. Avoid insufficient cooling capacity of the heat exchanger 3 of 2.

Further, when the contact type temperature sensor 54c that directly detects the temperature of the heat storage material TS is used as the state detection sensor (54), the heat storage material TS is transferred from the solid phase to the liquid phase. Since the temperature becomes constant, the temperature detected by the contact-type temperature sensor 54c begins to rise from this state, and the temperature of the second heat exchanger 3 is the temperature of the heat storage material TS from the temperature detected by the contact-type temperature sensor 54c. If it is detected that the temperature exceeds the phase change temperature (To) or a predetermined value (T2) higher than that, the cooling capacity of the second heat exchanger 3 may not be secured.

Therefore, when a contact-type temperature sensor 54c that directly detects the temperature of the heat storage material TS is used as the state detection sensor 54, the second heat exchanger 3 is based on the temperature detected by the contact-type temperature sensor 54c. When it is detected that the temperature of the heat storage material TS exceeds the phase change temperature (To) or a predetermined value (T2) higher than that, the operation mode is switched from the heating operation to the dehumidifying heating operation, and the second heat exchange is performed. Avoid insufficient cooling capacity of the vessel 3.

By the way, in the above configuration, the frequency of switching between the heating operation and the dehumidifying heating operation is suppressed (particularly, the frequency of switching from the heating operation to the dehumidifying heating operation is suppressed), and the number of times of noise generation is suppressed. If the noise itself at the time of switching can be reduced, it is more preferable from the viewpoint of noise countermeasures.
Therefore, on the premise of the above configuration, when switching between the heating operation and the dehumidifying heating operation, as shown in FIG. 7, a first switching valve including an on-off valve for opening and closing the first bypass flow path 16. By keeping the refrigerant control unit (V-1) 15 in the open state and switching the second expansion device 14 from the throttle state to the closed state, the dehumidifying heating operation is switched to the heating operation, and the second expansion device 14 is switched. It is preferable to switch from the heating operation to the dehumidifying heating operation by switching from the closed state to the throttle state. In FIG. 7, for convenience of explanation, the pipeline filled with the high-pressure refrigerant is shown by a thick solid line.

In such a configuration, since the first refrigerant control unit 15 is maintained in the open state, the high-pressure refrigerant in the refrigerant path between the first heat exchanger 2 and the first expansion device 12 is second. It is possible to keep the supply up to the entrance of the expansion device 14 at all times, and even when switching from heating to dehumidification heating, it is possible to avoid a situation in which the high-pressure refrigerant suddenly flows into the second expansion device 14 and generates an abnormal noise. It is possible to eliminate the generation of abnormal noise when switching from the heating operation to the dehumidifying heating operation (Parallel).

In addition, in the above form, it may be changed as appropriate within the range which does not deviate from the object of this invention. For example, the difference between the heat load received by the refrigeration cycle 100 and the target blowing temperature is used as an index for switching the operation mode of the refrigeration cycle. However, as a representative of the heat load received by the refrigeration cycle 100, the outside air is used. The temperature may be used, or the cooling temperature (EVA temperature) of the second heat exchanger 3 or the like may be used.

1 Air conditioning unit 2 1st heat exchanger 3 2nd heat exchanger 4 Outdoor heat exchanger 11 Compressor 12 1st expansion device 13 Check valve 14 2nd expansion device 15 1st refrigerant control unit 16 1st bypass flow path 17 2nd refrigerant control unit 18 2nd bypass flow path 19 On-off valve 50 Control means 54 State detection sensor 54a Air temperature sensor 54b, 54c Contact type temperature sensor 54d Temperature pressure sensor 100 Refrigeration cycle TS Heat storage Material

Claims (10)

The compressor (11), the first heat exchanger (2) arranged in the air conditioning unit (1) and the ventilation amount is adjusted by the damper (10), and the first heat exchanger (2) arranged in the air conditioning unit (1). A second exchanger (3) arranged on the upstream side in the air conditioning unit (1) with respect to the first heat exchanger (2), and an outdoor heat exchanger (4) capable of exchanging heat with the outside air. ), A first expansion device (12) capable of narrowing and opening and closing the refrigerant flow path, and a second expansion device (14) capable of narrowing and closing the refrigerant flow path. death,
The compressor (11), the first heat exchanger (2), the first inflator (12), the outdoor heat exchanger (4), the second inflator (14), and the above. Connect the second heat exchanger (3) in a loop at least in this order.
Between the refrigerant flow path between the first heat exchanger (2) and the first expansion device (12) and between the vehicle interior heat exchanger (4) and the second expansion device (14). Is connected to the refrigerant flow path of the above via a first bypass flow path (16) that can be opened and closed by the first refrigerant control unit (15).
Of the refrigerant flow paths between the vehicle interior heat exchanger (4) and the second expansion device (14), upstream of the merging portion (A) with the first bypass flow path (16). A backflow blocking portion (13) that blocks the flow of the refrigerant from the merging portion (A) to the upstream side is provided, and the refrigerant flow between the vehicle interior heat exchanger (4) and the backflow blocking portion (13). A second bypass flow path (18) provided with a second refrigerant control unit (17) for the refrigerant flow path between the path, the second heat exchanger (3), and the compressor (11). In a vehicle air conditioner having a refrigeration cycle (100) connected via
A vehicle air conditioner characterized in that a heat storage material (TS) is provided in the second heat exchanger (3). A control means (50) for switching and controlling the refrigeration cycle (100) and the operation mode of the refrigeration cycle (100) is provided.
The control means (50) is
The refrigerant discharged from the compressor (11) is dissipated by the first heat exchanger (2), and the dissipated refrigerant is depressurized by the first expansion device (12), and then the outside heat of the passenger compartment is generated. Heating that absorbs heat in the exchanger (4) and then returns it to the compressor (11) via the second bypass flow path (18) without allowing the second heat exchanger (3) to flow through. Driving and
The refrigerant discharged from the compressor (11) is radiated by the first heat exchanger (2), and the radiated refrigerant is branched, while passing through the first bypass flow path (16). The heat is absorbed through the second heat exchanger (3) after being depressurized by the second inflator (14), and on the other hand, the heat is exchanged outside the passenger compartment after being decompressed by the first inflator (12). A dehumidifying and heating operation in which heat is absorbed by the vessel (4) and returned to the compressor (11) via the second bypass flow path (18).
The vehicle air conditioner according to claim 1, wherein the air conditioner can be switched. A state detection sensor (54) for detecting the temperature state of the second heat exchanger (3) is provided.
The control means (50) is
It is estimated by the state detection sensor (54) that the temperature of the second heat exchanger (3) has fallen below the phase change temperature (T0) of the heat storage material (TS) or a predetermined value (T1) lower than that. When it is detected or detected, or when it is detected that the wetness of the refrigerant flowing out from the second heat exchanger exceeds a predetermined value (S1) larger than zero, the heating from the dehumidifying and heating operation is performed. The vehicle air conditioner according to claim 2, wherein the air conditioner is switched to operation. A state detection sensor (54) for detecting the temperature state of the second heat exchanger (3) is provided.
The control means (50) is
It is estimated by the state detection sensor (54) that the temperature of the second heat exchanger (3) exceeds the phase change temperature (T0) of the heat storage material (TS) or a predetermined value (T2) higher than that. The vehicle air conditioner according to claim 2, wherein the heating operation is switched to the dehumidifying heating operation when the heating operation is performed or detected. The vehicle according to claim 3 or 4, wherein the state detection sensor (54) is an air temperature sensor (54a) that detects the temperature of the air on the downstream side of the second heat exchanger (3). Air conditioner for. According to claim 3 or 4, the state detection sensor (54) is a contact type temperature sensor (54b, 54c) that directly detects the temperature of the second heat exchanger or the heat storage material. The vehicle air conditioner described. The vehicle use according to claim 3, wherein the state detection sensor (54) is a temperature / pressure sensor (54d) that detects the wetness of the refrigerant flowing out from the second heat exchanger (3). Air conditioner. The control means (50) switches between the heating operation and the dehumidifying heating operation.
With the second refrigerant control unit (17) maintained in the open state,
Switching from the dehumidifying heating operation to the heating operation by switching the second expansion device (14) from the throttle state to the closed state, and switching the second expansion device (14) from the closed state to the throttle state. The vehicle air conditioner according to any one of claims 2 to 7, wherein the heating operation is switched to the dehumidifying heating operation. In the operation mode switching control method for switching between the heating operation and the dehumidifying heating operation by using the vehicle air conditioner according to claim 2.
When it is estimated or detected that the temperature of the second heat exchanger (3) is lower than the phase change temperature (T0) of the heat storage material (TS) or a predetermined value (T1) lower than that, or When it is detected that the wetness of the refrigerant flowing out of the second heat exchanger exceeds a predetermined value (S1) larger than zero, the dehumidifying and heating operation is switched to the heating operation.
When it is estimated or detected that the temperature of the second heat exchanger (3) exceeds the phase change temperature (T0) of the heat storage material (TS) or a predetermined value (T2) higher than that. An operation mode switching control method characterized by switching from a heating operation to the dehumidifying heating operation. In the operation mode switching control method for switching between the heating operation and the dehumidifying heating operation by using the vehicle air conditioner according to claim 2.
The second refrigerant control unit (17) is maintained in an open state, and the second refrigerant control unit (17) is maintained in an open state.
By switching the second expansion device from the throttle state to the closed state, the dehumidifying heating operation is switched to the heating operation, and by switching the second expansion device from the closed state to the throttle state, the heating operation is changed to the heating operation. An operation mode switching control method characterized by switching to dehumidifying and heating operation.

Images