JP5640485B2 - Air conditioner for vehicles - Google Patents

Description

  The present invention relates to a vehicle air conditioner that can heat a vehicle interior used in an electric vehicle, a hybrid vehicle, or the like that is difficult to obtain a heat source for heating.

  Conventionally, in an engine vehicle, for example, a vehicle air conditioner has been devised that includes a total heat exchanger that absorbs heat from inside air during intake and exhaust and dissipates heat to the outside air and a refrigeration cycle, and that uses exhaust heat from the engine for heating. (For example, refer to Patent Document 1).

  This vehicle air conditioner can increase the temperature of the outside air by utilizing the heat of the inside air, so that heat loss due to the introduction of the outside air can be reduced and the heating effect can be improved. The evaporator (cooling heat) of the refrigeration cycle can be improved. The heater core (heating heat exchanger) which uses engine cooling water (hot water) as a heat source is disposed on the air downstream side of the exchanger. And, as the air conditioning temperature control system, an air mix system that adjusts the mixing ratio of cold and hot air is adopted, and the heater core is adjusted by the opening degree of the air mix door arranged on the upstream side of the heater core and on the downstream side of the evaporator. The temperature of the air blown into the passenger compartment is controlled by adjusting the air volume ratio between the passing hot air and the cold air bypassing the heater core.

  On the other hand, in air conditioners of electric vehicles and hybrid vehicles, a system using a cooler that drives a compressor with a motor and an electric heater is used in part.

  Recently, a system using a heat pump cycle has become mainstream from the viewpoint of power saving during heating, and there is a system that performs cooling, heating, dehumidification, etc. using a refrigeration cycle that drives and controls an electric compressor (for example, non-patent) Reference 1).

  FIG. 3 shows an example of a heat pump system using a four-way valve. The refrigerant during cooling is discharged from the compressor 101, flows through the outdoor heat exchanger 103 through the four-way valve 102, dissipates heat, depressurizes with the cooling throttle 104, absorbs heat with the evaporator (evaporator) 105, and returns to the compressor 101.

  At the time of heating, the four-way valve 102 is switched, the refrigerant flows through the condenser 106 to dissipate heat, and the outdoor heat exchanger 103 is operated as an evaporator. In the case of dehumidification, a so-called reheat method is adopted in which a refrigerant is passed in the order of the condenser 106, the heating throttle 107, the outdoor heat exchanger 103, the cooling throttle 104, the evaporator 105, etc., and the air is cooled and dehumidified to perform overheating.

Japanese Patent Laid-Open No. 10-16531

Electric Vehicle Handbook Editorial Committee “Electric Vehicle Handbook” published by Maruzen Co., Ltd. (Fig. 5.151)

  In such a conventional vehicle air conditioner, the former can use the heat of the inside air to bring the temperature of the outside air close to the temperature of the inside air, so heat loss due to the introduction of the outside air can be reduced. However, there has been a problem that an air conditioning system for vehicles capable of effectively recovering heat has not been devised.

  Therefore, the present invention solves the above-described conventional problems, and an object thereof is to provide a vehicle air conditioner that can effectively recover heat in a heat pump system.

In order to achieve this object, the present invention provides a supply air passage from an outside air introduction port for introducing outside air to an air conditioning outlet for blowing conditioned air into the vehicle, and an inside air from the inside air introduction port for introducing inside air. An inside air discharge path to the inside air discharge port for discharging to the outside air, an outside air blowing means for generating an air flow from the outside air introduction port to the air conditioning outlet in the supply air blowing passage, and an inside air discharge passage from the inside air introduction port to the inside air discharge passage An inside air blowing means for generating an air flow toward the inside air discharge port, a first in-vehicle heat exchanger and a second in-vehicle heat exchanger for cooling or heating air flowing through the supply air passage, a condenser during cooling operation, An outside heat exchanger that exchanges heat with outside air as an evaporator during heating operation, the first in-vehicle heat exchanger, the second in-vehicle heat exchanger, and a heat pump that circulates refrigerant between the outside heat exchanger and the compressor; The above A heat recovery unit that recovers heat by exchanging heat between the inside air flowing through the discharge path and the outside air introduced from the outside air introduction port, the heat recovery unit, and a sensible heat unit that exchanges only sensible heat, It is composed of a total heat part that exchanges heat, and during cooling operation , if the outside air is high humidity, use only the total heat part of the heat recovery unit, and if the outside air is low humidity, use the sensible heat part. Using both the total heat part, during heating operation , if the outside air is low humidity, use both the sensible heat part and the total heat part of the heat recovery unit, and if the outside air is high humidity and the window is clouded, etc. When dehumidification is necessary, only the sensible heat part is used, and the inside air that has passed through the heat recovery device is blown to the outside heat exchanger, thereby achieving the intended purpose.

  According to the present invention, the outside air that has passed through the heat recovery device is blown to the outside heat exchanger, so that heat is recovered from the inside air that is discharged outside the vehicle, and during cooling, the temperature of the outside heat exchanger is increased from the outside air to a part of the outside heat exchanger. Therefore, it is possible to lower the condensation temperature of the refrigerant, lower the evaporation temperature of the refrigerant in the first in-vehicle heat exchanger, and lower the temperature from the air conditioning outlet than sending only the outside air to the outside heat exchanger. It is possible to obtain an effect that it is possible to blow out cold air having a low temperature.

  Moreover, since the inside air whose temperature is higher than the outside air can be blown to a part of the outside heat exchanger during heating, the evaporation temperature of the refrigerant can be increased, the condensation temperature of the refrigerant in the second in-vehicle heat exchanger can also be increased, and the outside heat exchanger Therefore, it is possible to obtain an effect that hot air having a higher temperature can be blown out from the air-conditioning outlet than when only the outside air is blown.

Furthermore, heat recovery is performed from the air-conditioned interior air by providing a heat recovery unit that recovers heat by exchanging heat between the inside air flowing through the inside air discharge path and the outside air introduced from the outside air introduction port. Since the outside air to be introduced can be brought close to the in-vehicle environment, the effect of reducing the air-conditioning load in the vehicle and providing a vehicle air-conditioning device having an energy saving effect can be obtained.
Furthermore, the heat recovery unit is configured by a sensible heat part that exchanges only sensible heat and a total heat part that exchanges total heat. When the outside air is highly humid during cooling operation , the heat recovery unit When the outside air is low humidity, both the sensible heat portion and the total heat portion are used. During heating operation, when the outside air is low humidity, the sensible heat of the heat recovery unit is used. When the outside air is highly humid or when dehumidification is necessary, for example, when the window is cloudy, only the sensible heat part is used. If the outside air is low humidity, it is preferable to use both the sensible heat part and the total heat part, and when the outside air is high humidity or the window is cloudy, etc. When dehumidification is required, it is preferable to use only the sensible heat part. The internal air, which has a higher temperature than the outside air, is not discharged as it is, but is discharged after the heat recovery unit exchanges heat with the outside air, which reduces the heating load due to the refrigerant in the second in-vehicle heat exchanger and reduces the power consumption of the compressor. Can be reduced.
Furthermore, the air volume also changes depending on the pressure loss when flowing to both the sensible heat section and the total heat section, or when only one of them is flowed, so if you want to secure the air volume, apply it to both the sensible heat section and the total heat section. It is preferable to flow.

1 is a schematic configuration diagram of a vehicle air conditioner according to Embodiment 1 of the present invention. The image figure which shows the heat recovery device of Embodiment 2 of this invention Schematic configuration diagram of a conventional heat pump system for a vehicle air conditioner

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

(Embodiment 1)
As shown in FIG. 1, the vehicle air conditioner includes an outside air and inside air blowing path and a heat pump system.

  In the outside air and inside air blowing path, the inside air is directed from the outside air inlet 1 for introducing outside air to the air conditioning outlet 2 for blowing the conditioned air into the vehicle, and from the inside air inlet 4 to the inside air outlet 7. An inside air discharge path 8 for discharging outside the vehicle, an outside air blowing means 9a for generating an air flow from the outside air introduction port 1 to the air conditioning outlet 2 in the supply air blowing path 3, and an inside air discharge from the inside air introduction port 4 to the inside air discharge path 8 An inside air blowing means 9b that generates an air flow toward the path 8 and a first in-vehicle heat exchanger 10 and a second in-vehicle heat exchanger 11 that cool or heat the air flowing through the supply air blowing path 3 are provided.

  The inside air inlet 4 is provided with a temperature sensor 5 as an inside air temperature detecting means for detecting the air temperature inside the vehicle and a temperature sensor 6 as an outside air temperature detecting means for detecting the air temperature outside the vehicle.

  As a heat source, an external heat exchanger 12 for exchanging heat with the outside air as a condenser during cooling operation and an evaporator during heating operation is provided in an air passage different from the air supply air passage 3, and the first in-vehicle heat exchanger 10, The heat pump which circulates a refrigerant | coolant between the 2nd in-vehicle heat exchanger 11, the external heat exchanger 12, and the compressor 13 is provided.

  Here, the configuration of the heat pump will be described.

  On the high-pressure refrigerant discharge side of the compressor 13, a four-way valve 14, a check valve 15 between the four-way valve 14 and the vehicle exterior heat exchanger 12, and a throttle valve 16 (between the vehicle exterior heat exchanger 12 and the first vehicle interior heat exchanger 10 ( As shown in the figure, an expansion valve 16a and an electromagnetic valve 16b are incorporated), and a check valve 17 and a throttle valve 18 (an expansion valve 18a as shown in the figure) are disposed between the second in-vehicle heat exchanger 11 and the outside heat exchanger 12. A solenoid valve 18b is built in) to constitute a heat pump. Here, in the present embodiment, the temperature sensor 6 as the above-described outside air temperature detecting means is provided on the suction side of the outside heat exchanger 12.

  A heat recovery unit 19 that absorbs heat from the inside air flowing through the inside air discharge path 8 and dissipates heat to the outside air introduced from the outside air introduction port 1 is provided. The heat recovery unit 19 is a total heat exchanger that exchanges both sensible heat and latent heat.

  The feature of the present application is that the inside air that has passed through the heat recovery device 19 is blown to the outside heat exchanger 12. In this embodiment, a part of the outside heat exchanger 12 is connected to the inside air discharge port 7 and the heat recovery device 19. It is provided in the inside air discharge path 8 between.

  In the above configuration, each operation mode described in Table 1 will be described.

  First, the flow of the refrigerant during the cooling operation is as follows: compressor 13 → four-way valve 14 → check valve 15 → external heat exchanger 12 → throttle valve 16 → first in-vehicle heat exchanger 10 → compressor 13; No refrigerant flows through the exchanger 11.

  In such a refrigerant flow, the outside air is introduced from the outside air introduction port 1 by the operation of the outside air blowing means 9a, cooled to the inside air having a temperature lower than that of the outside air by the heat recovery device 19, and evaporated through the supply air blowing path 3. Cooled by the heat of vaporization of the refrigerant when passing through the first in-vehicle heat exchanger 10 acting as a cooler, passes through the second in-vehicle heat exchanger 11 where no refrigerant flows, and blows out cool air from the air conditioning outlet 2 to the windshield and the driver. . The blown-out cool air becomes inside air and circulates inside the vehicle. After the inside air blowing means 9b is operated, the cold air is warmed to the outside air by the heat recovery device 19 in the inside air discharge path 8 from the inside air introduction port 4, and then the refrigerant in the outside heat exchanger 12 Is further warmed by the heat of condensation, and is discharged from the inside air outlet 7 to the outside of the vehicle.

  In this way, the inside air having a temperature lower than that of the outside air is not discharged as it is, but is exchanged with the outside air by the heat recovery device 19 and further discharged after passing through the outside heat exchanger 12. Therefore, the first inside heat exchanger The cooling load by the refrigerant at 10 is reduced, and the power consumption of the compressor 13 can be reduced.

  Moreover, even when the outside air temperature is high and the evaporation temperature of the refrigerant in the refrigeration cycle becomes high, the inside air having a temperature lower than the outside air is blown to the outside heat exchanger 12 acting as a condenser to liquefy the refrigerant. Since it can accelerate | stimulate, the evaporation temperature of the refrigerant | coolant in the 1st in-vehicle heat exchanger 10 can also be made low, and the fall of a cooling capability can be suppressed.

  Next, the refrigerant flow during the heating operation is as follows: compressor 13 → four-way valve 14 → second in-vehicle heat exchanger 11 → throttle valve 18 → outside heat exchanger 12 → electromagnetic valve 16b → compressor 13; No refrigerant flows through the exchanger 10.

  In such a refrigerant flow, the outside air is introduced from the outside air introduction port 1 by the operation of the outside air blowing means 9a, warmed to the inside air having a temperature higher than the outside air by the heat recovery device 19, and passes through the supply air blowing path 3, When the air passes through the first in-vehicle heat exchanger 10 where the air does not flow and passes through the second in-vehicle heat exchanger 11 acting as a condenser, it is heated by the condensation heat of the refrigerant, and warm air is blown from the air conditioning outlet 2 to the windshield and the driver. Blow out. The blown warm air becomes the inside air and circulates inside the vehicle, and is cooled to the outside air by the heat recovery device 19 in the inside air discharge path 8 from the inside air introduction port 4 by the operation of the inside air blowing means 9b, and discharged from the inside air discharge port 7 to the outside of the vehicle. Is done.

  In this way, the inside air having a temperature higher than the outside air is not discharged as it is, but is exchanged with the outside air by the heat recovery unit 19 and further discharged after passing through the outside heat exchanger 12, so that the second inside heat exchanger The heating load due to the refrigerant at 11 is reduced, and the power consumption of the compressor 13 can be reduced.

  Moreover, even when the outside air temperature is low and the condensation temperature of the refrigerant in the refrigeration cycle is also lowered, the inside air having a temperature higher than the outside air is blown to the outside heat exchanger 12 acting as an evaporator to evaporate the refrigerant. Since it can accelerate | stimulate, the condensing temperature of the refrigerant | coolant in the 1st in-vehicle heat exchanger 10 can also be made high, and the fall of heating capability can be suppressed.

  In addition, when dehumidification is required such as the window being clouded during heating (first dehumidifying heating in Table 1), for example, the temperature of the outside air detected by the temperature sensor 6 as dew condensation detection means is the room temperature detected by the temperature sensor 5 (or the air conditioning in the vehicle). If the temperature is lower than the dew point temperature), the refrigerant flows through the first heat exchanger 10 after the vehicle heat exchanger 12 to act as an evaporator, and the outside air is cooled and dehumidified when passing through the first heat exchanger 10. By doing so, low-humidity warm air can be blown out from the air conditioning outlet 2 to the windshield and the driver.

  Here, the dew point temperature inside the vehicle changes depending on the humidity inside the vehicle, but by setting the general relative humidity 50 to 60% during heating, the dew point temperature inside the vehicle can be calculated. It can be judged whether there is cloudiness. Further, a humidity sensor (not shown) is provided in the vicinity of the temperature sensor 5 as the inside air temperature detecting means as a humidity detecting means for detecting the inside humidity of the car, and the dew point temperature inside the car is calculated using the detected humidity. It is possible to more accurately determine the presence or absence of cloudiness.

  At this time, when it is desired to eliminate the fogging of the window quickly, the amount of refrigerant evaporated in the first in-vehicle heat exchanger 10 may be increased more than that in the outside heat exchanger 12. That is, by stopping the blower 20 for the vehicle exterior heat exchanger 12 or reducing the amount of blown air, the amount of refrigerant evaporated in the first in-vehicle heat exchanger 10 can be increased, and the dehumidifying capacity can be increased.

  Further, if the window is cloudy even after the above dehumidification (the second dehumidifying heating in Table 1), the outside air inlet 1 is closed by the damper 21, the damper 21 a of the outside air inlet 1 a is opened, and the outside air that does not pass through the heat recovery device 19. By introducing the outside air from the introduction port 1a, the humidity recovery from the inside air in the heat recovery device 19 is not performed, and therefore, hot air with lower humidity can be blown out from the air conditioning outlet 2 to the windshield and the driver.

  When the outside air is highly humid, that is, when the absolute humidity of the outside air is higher than the absolute humidity of the inside air, the damper 22 of the inside air introduction port 4, the damper 21 of the outside air introduction port 1, and the damper 21a of the outside air introduction port 1a are closed, Even when the inside air circulation is intermittently performed by opening the damper 22a of the normally closed inside air introduction port 4a, the dehumidifying load in the first in-vehicle heat exchanger 10 can be reduced, and wasteful power is not consumed. It is possible to suppress fogging of windows, particularly the windshield.

  As described above, since the inside air that has passed through the heat recovery device 19 is blown to the outside heat exchanger 12, heat is recovered from the inside air that is discharged outside the vehicle. Since the cooler internal air can be blown, the refrigerant condensing temperature can be lowered, the refrigerant evaporating temperature in the first in-vehicle heat exchanger 10 can also be lowered, and the air-conditioning blower can be used instead of blowing only the outside air to the outside heat exchanger 12. An effect that cold air having a lower temperature can be blown out from the outlet 2 can be obtained.

  Further, since the inside air having a temperature higher than the outside air can be blown to a part of the outside heat exchanger 12 during heating, the evaporation temperature of the refrigerant can be increased, the condensation temperature of the refrigerant in the second in-vehicle heat exchanger 11 can also be increased, and the outside heat The effect that hot air with higher temperature can be blown out from the air-conditioning blower outlet 2 can be obtained rather than blowing only the outside air into the exchanger 12.

  That is, it is possible to reduce the condensation temperature of the refrigerant in the external heat exchanger 12 that acts as a condenser during cooling, and to prevent an increase in the evaporation temperature of the refrigerant in the first in-vehicle heat exchanger 10 that acts as an evaporator. Since the refrigeration cycle can be maintained, the power consumption of the compressor 13 can be reduced.

  Further, heat recovery is performed from the air-conditioned interior air by providing a heat recovery unit 19 that performs heat exchange between the inside air flowing through the inside air discharge path 8 and the outside air introduced from the outside air inlet 1. Since the outside air to be introduced can be brought close to the vehicle interior environment, the effect of reducing the air conditioning load in the vehicle and providing a vehicle air conditioner having an energy saving effect can be obtained.

  In the present embodiment, a part of the vehicle exterior heat exchanger 12 is provided in the inside air discharge path 8 between the inside air discharge port 7 and the heat recovery unit 19, but not in the inside air discharge path 8 but in the inside air discharge port 7. It may be provided outside, and the same effect can be obtained.

(Embodiment 2)
Next, FIG. 2 shows another form of the heat recovery unit 19 described in the first embodiment.

  As shown in FIG. 2, the heat recovery unit 29 includes a sensible heat part 29 a that recovers only sensible heat (heat exchange) and a total heat part 29 b that recovers (heat exchange) total heat. Depending on the operation mode, the sensible heat part 29a and the total heat part 29b can be used properly.

  In the above configuration, the proper use of the heat recovery device 29 in each operation mode shown in Table 1 will be described.

  Since it is possible to reduce the cooling load when the humidity of the outside air is not put in the vehicle during the cooling operation, it is preferable to use only the total heat part 29b. When the outside air is low humidity, both the sensible heat part 29a and the total heat part 29b are used. May be used.

  During heating operation, when the outside air is low humidity, it is preferable to use both the sensible heat portion 29a and the total heat portion 29b. When the outside air is high humidity or when the dehumidification is necessary such as clouding of the window (the first in Table 1) It is preferable to use only the sensible heat portion 29a. That is, the heat recovery device 29 can be used also in the second dehumidifying heating in Table 1, and the internal air having a temperature higher than the outside air is not discharged as it is, but is discharged after the heat recovery device 19 exchanges heat with the outside air. Since it did in this way, the heating load by the refrigerant | coolant in the 2nd vehicle interior heat exchanger 11 reduces, and the power consumption of the compressor 13 can be reduced.

  In the present embodiment, the sensible heat part 29a and the total heat part 29b are represented by an image as shown in FIG. 2, but a damper for switching the air path is required to use the sensible heat part 29a and the total heat part 29b properly. Become.

  In addition, when the flow is made to flow through both the sensible heat portion 29a and the total heat portion 29b or when only one of them is flowed, the air volume also changes due to the difference in pressure loss. It is preferable to flow in both.

  Since the vehicle air conditioner according to the present invention recovers heat from the air-conditioned vehicle interior and can bring the outside air to be introduced closer to the vehicle interior environment, it can reduce the air conditioning load in the vehicle. It is useful as a vehicle air conditioner that can heat the passenger compartment used in electric vehicles, hybrid vehicles, and the like where it is difficult to obtain a heat source.

DESCRIPTION OF SYMBOLS 1, 1a Outside air introduction port 2 Air-conditioning blower outlet 3 Supply air ventilation path 4, 4a Inside air introduction port 5, 6 Temperature sensor 7 Inside air discharge port 8 Inside air discharge path 9a Outside air blowing means 9b Inside air blowing means 10 1st vehicle interior heat exchanger 11 Second heat exchanger 12 Inside heat exchanger 13 Compressor 14 Four-way valve 15, 17 Check valve 16, 18 Throttle valve 16a, 18a Expansion valve 16b, 18b Electromagnetic valve 19, 29 Heat recovery device 20 Blower 21, 21a, 22, 22a Damper 29a Sensible heat part 29b Total heat part

Claims (6)

An air supply air passage from an outside air inlet that introduces outside air to an air conditioning outlet that blows out conditioned air into the vehicle;
An inside air discharge path from an inside air introduction port for introducing inside air to an inside air discharge port for discharging inside air to the outside of the vehicle,
An outside air blowing means for generating an air flow from the outside air inlet to the air conditioning outlet in the supply air passage;
An inside air blowing means for generating an air flow from the inside air inlet to the inside air outlet in the inside air discharge path;
A first in-vehicle heat exchanger and a second in-vehicle heat exchanger for cooling or heating the air flowing through the air supply air passage;
An external heat exchanger that exchanges heat with outside air as a condenser during cooling operation and an evaporator during heating operation;
A heat pump that circulates refrigerant between the first in-vehicle heat exchanger, the second in-vehicle heat exchanger, and the external heat exchanger and the compressor;
A heat recovery unit that recovers heat by exchanging heat between the inside air flowing through the inside air discharge path and the outside air introduced from the outside air inlet;
The heat recovery unit is configured by a sensible heat part that exchanges only sensible heat and a total heat part that exchanges total heat. When the outside air is highly humid during cooling operation , the heat recovery unit When only the hot part is used and the outside air is low in humidity, both the sensible heat part and the total heat part are used, and during the heating operation , if the outside air is low in humidity, the sensible heat part of the heat recovery unit and the When both the total heat section is used and the outside air is highly humid or when dehumidification is required, such as when the window is clouded, only the sensible heat section is used, and the inside air that has passed through the heat recovery device is transferred to the outside heat exchanger. An air conditioner for a vehicle that blows air. 2. The vehicle air conditioner according to claim 1, wherein a part of the external heat exchanger is provided in an inside air discharge path between the inside air outlet and the heat recovery unit. It has an inside air temperature detecting means for detecting the air temperature inside the vehicle and an outside air temperature detecting means for detecting the air temperature outside the car,
The vehicle air conditioning according to any one of claims 1 to 2, wherein dehumidification during heating operation is controlled using the temperature detected by the inside air temperature detecting means and the temperature detected by the outside air temperature detecting means. apparatus. The vehicle air conditioner according to claim 3, further comprising a humidity detecting means for detecting the humidity inside the vehicle. The vehicle air conditioner according to claim 3 or 4, further comprising an outside air inlet that does not pass through the heat recovery unit. The vehicle air conditioner according to any one of claims 1 to 5, wherein a switching damper is provided at an inside air introduction port to switch between inside air circulation and outside air introduction.

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