AIR-CONDITIONING APPARATUS

摘要

A controller, at least during the heating operation, controls the opening degree of a second expansion device and/or a third expansion device based on a discharge refrigerant temperature detected by a discharge refrigerant temperature detector, or a value computed using the discharge refrigerant temperature, and causes refrigerant having a quality equal to or greater than 0.9 and less than or equal to 0.99 to be suctioned into a compressor.

主权项

1. An air-conditioning apparatus, including a compressor, a refrigerant flow switching device, a heat source side heat exchanger, a first expansion device, and an intermediate heat exchanger connected via refrigerant pipes, that constitutes a refrigerant circuit, and
a pump, the intermediate heat exchanger, and a use side heat exchanger connected via pipes, that constitutes a heat medium circuit B, the air-conditioning apparatus comprising: a second expansion device provided on an upstream side of the heat source side heat exchanger during a heating operation; an accumulator configured to accumulate excess refrigerant provided on an upstream side of the compressor; a suction injection pipe, having one end connected on an upstream side of the second expansion device during the heating operation, and another end connected to a flow channel between a suction side of the compressor and the accumulator; a third expansion device provided to the suction injection pipe; a discharge refrigerant temperature detector configured to detect a discharge refrigerant temperature of the compressor; and a controller configured to control an opening degree of the second expansion device and/or the third expansion device based on at least a detection result from the discharge refrigerant temperature detector; wherein, inside the refrigerant pipes, a refrigerant having a higher discharge refrigerant temperature than R410A is circulated as refrigerant, the controller, during the heating operation, performs discharge temperature control that controls an opening degree of the third expansion device based on a deviation between one of a target value of the discharge refrigerant temperature and a target value related to the discharge refrigerant temperature, and any one of the discharge refrigerant temperature detected by the discharge refrigerant temperature detector, a value related to the discharge refrigerant temperature computed using the detected discharge refrigerant temperature, and a predicted value of the discharge refrigerant temperature or of a value related to the discharge refrigerant temperature computed using the detected discharge refrigerant temperature, and causes refrigerant having a quality equal to or greater than 0.9 and less than or equal to 0.99 to be suctioned into the compressor.