Vehicular air conditioner

Abstract

In a vehicular air conditioner which controls an output refrigerant pressure of a radiator by adjusting a decompression amount in an expansion valve, an air conditioning ECU calculates a target refrigerant pressure using a refrigerant temperature detected by a temperature sensor, a vehicle speed detected by a vehicle speed detector, and a control equation defined for calculating the target refrigerant pressure, and adjusts an opening of an expansion valve by a decompression amount corresponding to the target refrigerant pressure.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a system block diagram of a vehicular air conditioner according to an embodiment of the present invention; and

FIG. 2 is a flowchart showing processing procedure for calculating the target refrigerant pressure in the refrigeration cycle device according to an embodiment of the present invention.

Claims

1. A vehicular air conditioner comprising a compressor for compressing a refrigerant, a radiator for cooling the refrigerant compressed by the compressor by heat exchange with cooling wind, a temperature sensor for detecting a refrigerant temperature on the side of an outlet of the radiator, a decompressor for decompressing the refrigerant which passes through the radiator in accordance with a designated decompression amount, an evaporator for evaporating the refrigerant which passes through the decompressor by heat exchange with conditioned wind, a gas/liquid separator for separating the refrigerant discharged from the evaporator into gas and liquid, a vehicle speed detector for detecting a vehicle speed, and a control for designating the decompression amount for the decompressor, wherein the control calculates a target refrigerant pressure using the refrigerant temperature detected by the temperature sensor, a vehicle speed detected by the vehicle speed detector and a control equation defined for calculating the target refrigerant pressure, and the control designates the decompression amount corresponding to the target refrigerant pressure for the decompressor.

2. The vehicular air conditioner according to claim 1, wherein in the control equation defined for calculating the target refrigerant pressure, the control defines a difference between a temperature of outside air and a temperature of a air which reversely flows through the radiator, as a maximum value of temperature to be used as a correction value.

3. The vehicular air conditioner according to claim 1, wherein the control includes, in the control equation defined for calculating the target refrigerant pressure, a temperature correction term obtained by dividing, by the vehicle speed detected by the vehicle speed detector, a correction value which is a difference between a temperature of outside air and a temperature of air which reversely flows through the radiator.