JP2008224135A5 - - Google Patents

Claims (4)

A refrigerant circuit in which at least a compressor, a four-way switching valve, an indoor heat exchanger, a first pressure reducing device, and an outdoor heat exchanger are coupled in a closed loop with refrigerant piping;
Outdoor unit refrigerant temperature detection means for detecting the refrigerant temperature of the outdoor heat exchanger;
Outside temperature detecting means for detecting outside temperature;
Previous defrost prohibition time for defrosting time of heating operation in accordance with the length in succession is the configurable, detected at the detected outdoor-refrigerant temperature in the outdoor-refrigerant temperature detecting means and the outside air temperature detecting means The amount of frost formation on the outdoor heat exchanger is determined from the temperature difference from the outside air temperature, and when it is determined that the amount of frost formation is small, the defrosting prohibition time is set longer and the outdoor heat exchange is performed. When it is determined that the amount of frost on the heater is large, the frost removal prohibition time is set short, and after performing the heating operation for a certain period of time, the heating capacity of the indoor heat exchanger decreases due to the frost formation. A control device that controls to perform the defrosting operation by switching the four-way switching valve when it is determined that,
A refrigeration apparatus comprising:   The indoor heat exchanger is a heat exchanger of an indoor unit of an air conditioner, and the indoor unit is provided with indoor blown air temperature detecting means and indoor air temperature detecting means, and the control device is provided with the indoor blown air. 2. The refrigeration apparatus according to claim 1, wherein a decrease in heating capacity is determined from a difference between an indoor blown air temperature detected by the temperature detecting means and an indoor air temperature detected by the indoor air temperature detecting means.   The indoor heat exchanger is a heat exchanger of an indoor unit of an air conditioner, and the indoor unit is provided with a refrigerant temperature detecting means and an indoor air temperature detecting means for detecting the refrigerant temperature of the indoor heat exchanger. The controller determines a decrease in heating capacity from the difference between the refrigerant temperature of the indoor heat exchanger detected by the refrigerant temperature detecting means and the indoor air temperature detected by the indoor air temperature detecting means. The refrigeration apparatus according to claim 1. An intermediate pressure receiver for exchanging heat with the refrigerant sucked into the compressor is provided between the indoor heat exchanger and the first pressure reducing device, and the intermediate pressure receiver and the indoor heat A second pressure reducing device is newly provided between the exchangers,
The controller is configured to reduce the degree of superheat of the refrigerant sucked into the compressor and the degree of refrigerant superheat at the outlet of the heat exchanger acting as an evaporator by a decompression device positioned downstream of the intermediate pressure receiver with respect to the refrigerant flow. , The compressor discharge temperature or the compressor discharge refrigerant superheat degree is controlled so as to be a predetermined target value, and is positioned upstream of the intermediate pressure receiver with respect to the refrigerant flow The refrigeration according to any one of claims 1 to 3, wherein the pressure reduction device controls the degree of supercooling at the outlet of the heat exchanger acting as a condenser to a predetermined target value. apparatus.