Refrigeration cycle device for vehicle
A refrigerant cycle device includes a compressor, a radiator, a first expansion valve, a second expansion valve, a first evaporator, a second evaporator, and a controller. The controller is configured to switch between a first evaporator priority control and a second evaporator priority control. During the first evaporator priority control, the controller controls a throttle opening of the second expansion valve based on at least one of a temperature of a first evaporator, a temperature of a refrigerant flowing through the first evaporator, and a temperature of an air having exchanged heat in the first evaporator. During the second evaporator priority mode, the controller controls the throttle opening based on a refrigerant state of the second evaporator. When the at least one of the temperatures is equal to or greater than a switching temperature, the second priority mode is switched to the first priority mode.
1. A refrigerant cycle device for a vehicle comprising:
a compressor that is configured to draw and discharge a refrigerant;
a radiator that is configured to radiate a heat of the refrigerant discharged from the compressor;
a first expansion valve and a second expansion valve that are disposed in parallel with each other and configured to decompress the refrigerant having released the heat in the radiator;
a first evaporator that is configured to exchange heat between the refrigerant having been decompressed by the first expansion valve and an air to be blown to a vehicle cabin to evaporate the refrigerant;
a second evaporator that is configured to exchange heat between the refrigerant having been decompressed by the second expansion valve and a heat medium for cooling a battery; and
a controller that is configured to control a throttle opening of the second expansion valve, wherein
the controller is configured to switch between a first evaporator priority control and a second evaporator priority control,
the controller is configured to:
control the throttle opening of the second expansion valve according to a refrigerant condition in the second evaporator during the second evaporator priority control; and
control the throttle opening of the second expansion valve according to at least one of a temperature of the first evaporator, a temperature of the refrigerant flowing through the first evaporator, and a temperature of the air having exchanged heat in the first evaporator during the first evaporator priority control, and
the controller is configured to switch the second evaporator priority control to the first evaporator priority control when the at least one of the temperatures is equal to or higher than a switching temperature in the second evaporator priority control.
2. The refrigerant cycle device according to claim 1 , wherein
the controller is configured to increase the switching temperature as a temperature of the battery or a temperature of the heat medium increases.
3. The refrigerant cycle device according to claim 1 , wherein the controller is further configured to:
switch between the first evaporator priority control and the second evaporator priority control by opening the second expansion valve when a temperature of the heat medium or a temperature of the battery is higher than an opening valve temperature; and
refrain from executing both the first evaporator priority control and the second evaporator priority control by closing the second expansion valve when the temperature of the heat medium or the temperature of the battery is lower than the opening valve temperature.
4. The refrigerant cycle device according to claim 1 , wherein
when the battery needs to be cooled, the controller is configured to:
close the second expansion valve when the temperature of the first evaporator is higher than a predetermined evaporator temperature; and
open the second expansion valve when the temperature of the first evaporator is equal to or lower than the predetermined evaporator temperature.
5. The refrigerant cycle device according to claim 1 , wherein
the controller is further configured to set the throttle opening of the second expansion valve or an increase rate of the throttle opening of the second expansion valve to a value equal to or less than a predetermined value when cooling the battery.
6. The refrigerant cycle device according to claim 1 , wherein
the controller is configured to set a decrease rate of the throttle opening of the second expansion valve to a value equal to or less than a predetermined decrease rate when the battery does not need to be cooled.
7. The refrigerant cycle device according to claim 1 , wherein
the controller is further configured to open the second expansion valve and control the throttle opening of the second expansion valve during the second evaporator priority control and open the second expansion valve and control the throttle opening of the second expansion valve during the first evaporator priority control.