AIR-CONDITIONING DEVICE, RAILWAY VEHICLE AIR-CONDITIONING DEVICE, AND METHOD FOR CONTROLLING AIR-CONDITIONING DEVICE

摘要

An air-conditioning device includes (i) a compressor, (ii) an outdoor heat exchanger, (iii) an indoor heat exchanger and an electronic expansion valve, (iv) a bypass passage connecting a middle compression chamber and a low pressure space, the middle compression chamber accommodating a refrigerant undergoing compression by the compressor, the low pressure space accommodating the refrigerant having a pressure lower than a pressure of the refrigerant in the middle compression chamber, (v) a bypass valve to open or close the bypass passage, and (vi) a controller to set a degree of opening of the electronic expansion valve based on a degree of superheat of a refrigerant. Based on a change from a closed state of the bypass valve to an open state, the controller corrects the degree of opening of the electronic expansion valve to a value that is less than a value set by the degree-of-superheat control.