HEAT RECOVERY MULTI-SPLIT AIR CONDITIONER AND CONTROL METHOD THEREFOR

摘要

A heat recovery multi-split air conditioner and a control method therefor. The heat recovery multi-split air conditioner comprises a high-pressure air pipe (18), a low-pressure air pipe (20) and an outdoor unit. The high-pressure air pipe (18) is separately connected to the high-pressure side of the outdoor unit and the low-pressure side of the outdoor unit through control valves and connecting pipelines. The low-pressure air pipe (20) is connected to the low-pressure side of the outdoor unit. The control method for the heat recovery multi-split air conditioner comprises when it is determined that the heat recovery multi-split air conditioner is in a complete refrigeration mode, controlling the high-pressure air pipe (18) to be communicated with the low-pressure side of the outdoor unit. According to the heat recovery multi-split air conditioner and the control method therefor, when the heat recovery multi-split air conditioner is in the complete refrigeration mode, the high-pressure air pipe (18) is switched to the low-pressure air pipe, a dual-low-pressure pipeline system is formed, and refrigerants can simultaneously return to the outdoor unit through the low-pressure air pipe (20) and the high-pressure air pipe (18) after entering indoor units (6, 7, 8) through a medium-pressure liquid pipe (19) to participate in refrigeration and heat exchange so that systemic circulation is completed. By means of the heat recovery multi-split air conditioner and the control method therefor, the utilization rate of the refrigerants is greatly increased, the pressure drop on the low-pressure side of the outdoor unit is greatly decreased, and the energy efficiency level of the heat recovery multi-split air conditioner in the complete refrigeration mode is improved.