JP4612968B2 - Air conditioner for vehicles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle air conditioner.
[0002]
[Prior art]
Conventionally, as a vehicle air conditioner, the temperature of the refrigerant flowing through the condenser outlet side high-pressure passage from the outlet side of the condenser in the refrigeration cycle to the inlet side of the pressure reducing valve is detected, and the optimum pressure of the refrigerant flowing through the high-pressure passage is determined from this refrigerant temperature. And the coefficient of performance of the refrigeration cycle is improved by determining whether or not the actual high pressure in the high pressure passage is greater than the optimum high pressure (Japanese Patent Laid-Open No. 7-294033).
[0003]
[Problems to be solved by the invention]
Usually, the vehicle exterior heat exchanger is cooled by a vehicle blower, and the air flow rate is constant. For this reason, even when the vehicle exterior heat exchanger is not required to be cooled as much as when the vehicle is running or immediately after the engine is started, air is blown by the vehicle outside blower, and power is wasted. Therefore, even if the driving control is performed so as to improve the coefficient of performance of the folding angle and the refrigeration cycle, such an efficient control cannot be performed in the whole apparatus.
[0004]
Then, this invention makes it a subject to provide the vehicle air conditioner which can improve a driving | running efficiency by driving a blower for vehicles outside appropriately.
[0005]
[Means for Solving the Problems]
As a means for solving the above problems, the present invention provides:
In a vehicle air conditioner equipped with a refrigeration cycle in which refrigerant discharged from a compressor is radiated by a heat exchanger outside the vehicle, depressurized by a pressure reducing valve, vaporized by a heat exchanger inside the vehicle, and then returned to the compressor for circulation. ,
The refrigerant is CO ₂ ;
An external blower capable of changing the air flow rate to the vehicle exterior heat exchanger;
Refrigerant temperature detecting means for detecting the refrigerant temperature on the outlet side of the vehicle exterior heat exchanger;
Outside temperature detecting means for detecting outside temperature;
Control means for controlling so that the amount of air blown by the outside blower increases as the temperature difference between the outside air temperature detected by the outside air temperature detecting means and the refrigerant temperature detected by the refrigerant temperature detecting means increases. It is provided.
[0006]
With this configuration, it is possible to adjust the amount of air blown by the outside blower according to the difference between the outside air temperature and the refrigerant temperature. Therefore, when it is not necessary to increase the heat radiation amount from the refrigerant by blowing air to the vehicle outside heat exchanger, it is possible to reduce the amount of air blown by the vehicle external blower and suppress wasteful power consumption.
[0007]
It is preferable that the outside air temperature detection means is provided in the vicinity of the vehicle outside heat exchanger in that it can accurately detect a temperature increase in the vicinity of the vehicle outside heat exchanger when the vehicle is stopped (idling). .
[0008]
When the temperature difference between the outside air temperature detected by the outside air temperature detecting means and the refrigerant temperature detected by the refrigerant temperature detecting means is 1 ° C. or less, the control means stops air blowing by the vehicle outside blower. That's fine .
[0009]
When the temperature difference between the outside air temperature detected by the outside air temperature detecting means and the refrigerant temperature detected by the refrigerant temperature detecting means is 5 ° C. or more, the control means maximizes the blowing by the vehicle outside blower. And it is sufficient.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments according to the present invention will be described below with reference to the accompanying drawings.
[0011]
FIG. 1 shows a refrigeration cycle C of a vehicle air conditioner according to this embodiment. In the refrigeration cycle C, the refrigerant discharged from the compressor 1 (here, CO2 is used) returns to the compressor 1 via the vehicle exterior heat exchanger 2, the pressure reducing valve 3, and the vehicle interior heat exchanger 4. Circulate. The compressor 1, the pressure reducing valve 3, and the vehicle blower 7 described later are driven and controlled by the control device 5.
[0012]
The compressor 1 can be driven by engine power (not shown).
[0013]
The vehicle exterior heat exchanger 2 has a conventionally well-known structure that is disposed in the front portion of the vehicle and is suitable for radiating the refrigerant. The vehicle exterior heat exchanger 2 includes a vehicle exterior blower 7 that is rotated by driving a blower motor 6. The blower 7 for the outside of the vehicle can freely change the amount of air blow, and the amount of heat released from the refrigerant in the outside heat exchanger 2 can be adjusted by changing the amount of air blow. A refrigerant sensor 8 for detecting the refrigerant temperature is provided on the outlet side pipe of the vehicle exterior heat exchanger 2. Further, an outside air sensor 9 for detecting the outside air temperature is provided in the vicinity of the vehicle exterior heat exchanger 2. Thus, by providing the outside air sensor 9 in the vicinity of the vehicle exterior heat exchanger 2, it is possible to accurately detect the temperature increase in the vicinity of the vehicle exterior heat exchanger 2 when the vehicle is stopped (idling).
[0014]
The pressure reducing valve 3 adjusts the upstream refrigerant pressure by changing the opening, and depressurizes the refrigerant passing therethrough.
[0015]
The vehicle interior heat exchanger 4 is disposed in the air conditioning unit 10 in the front part of the vehicle, and has a conventionally well-known structure for cooling and dehumidifying the air passing through the air conditioning unit 10.
[0016]
Based on the detection values of the refrigerant sensor 8 and the outside air sensor 9 and the like, the control device 5 determines the rotational speed of the compressor 1, the opening of the pressure reducing valve 3, and the amount of air blown by the outside blower 7 as described later. adjust.
[0017]
Next, the operation of the vehicle air conditioner having the above configuration will be described.
[0018]
First, the outside air temperature detected by the outside air sensor 9 and the refrigerant temperature detected by the refrigerant sensor 8 are read. Then, based on the difference between the outside air temperature and the refrigerant temperature, the voltage applied to the blower motor 6 for driving the vehicle blower 7 is calculated based on the graph of FIG. When the temperature difference is 1 ° C. or less, it is determined that the heat exchange efficiency of the outside heat exchanger 2 is very low , so the vehicle outside blower 7 is not driven. Further, if the temperature difference exceeds 1 ° C., the air flow rate is gradually increased as the temperature difference increases. However, when the temperature difference is about 5 ° C. and the blown amount by the vehicle blower 7 becomes the maximum value, if the temperature difference exceeds 5 ° C., the maximum value is maintained.
[0019]
As described above, since the amount of air blown by the vehicle blower 7 is controlled based on the outside air temperature and the refrigerant temperature, the total power consumption including the vehicle blower 7 can be reduced. Further, since the outside air sensor 9 is provided in the vicinity of the vehicle exterior heat exchanger 2, the temperature rise in the vicinity of the vehicle exterior heat exchanger 2 when the vehicle is stopped (idling), that is, the heat exchange efficiency of the vehicle exterior heat exchanger 2 is accurately determined. It becomes possible to detect .
[0020]
【The invention's effect】
As is apparent from the above description, according to the present invention, the amount of air blown by the outside blower is controlled based on the outside air temperature and the refrigerant temperature at the outlet side of the outside heat exchanger. As a result, wasteful power consumption in the vehicle is reduced, and the cooling capability of the vehicle interior heat exchanger can be efficiently exhibited.
[Brief description of the drawings]
FIG. 1 is a schematic view showing a refrigeration cycle of a vehicle air conditioner according to the present embodiment.
FIG. 2 is a graph showing the relationship between the difference between the outside air temperature and the refrigerant temperature and the voltage applied to the drive motor for the vehicle outside blower.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Compressor 2 ... Car exterior heat exchanger 3 ... Pressure reducing valve 4 ... Car interior heat exchanger 5 ... Control apparatus 6 ... Blower motor 7 ... Blower for vehicles outside 8 ... Refrigerant sensor 9 ... Outside air sensor 10 ... Air conditioning unit

Claims (4)

In a vehicle air conditioner equipped with a refrigeration cycle in which refrigerant discharged from a compressor is radiated by a heat exchanger outside the vehicle, depressurized by a pressure reducing valve, vaporized by a heat exchanger inside the vehicle, and then returned to the compressor for circulation. ,
The refrigerant is CO ₂ ;
An external blower capable of changing the air flow rate to the vehicle exterior heat exchanger;
Refrigerant temperature detecting means for detecting the refrigerant temperature on the outlet side of the vehicle exterior heat exchanger;
Outside temperature detecting means for detecting outside temperature;
Control means for controlling so that the amount of air blown by the outside blower increases as the temperature difference between the outside air temperature detected by the outside air temperature detecting means and the refrigerant temperature detected by the refrigerant temperature detecting means increases. An air conditioner for a vehicle, comprising:   2. The vehicle air conditioner according to claim 1, wherein the outside air temperature detecting means is provided in the vicinity of the vehicle exterior heat exchanger. When the temperature difference between the outside air temperature detected by the outside air temperature detecting unit and the refrigerant temperature detected by the refrigerant temperature detecting unit is 1 ° C. or less, the control unit stops air blowing by the vehicle outside blower. The vehicle air conditioner according to claim 1 or 2. When the temperature difference between the outside air temperature detected by the outside air temperature detecting means and the refrigerant temperature detected by the refrigerant temperature detecting means is 5 ° C. or more, the control means maximizes the blowing by the vehicle outside blower. air-conditioning system according to any one of claims 1 to 3, characterized in that a.

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