REFRIGERANT NATURAL CIRCULATION JOINTLY USED AIR CONDITIONER AND ITS OPERATION CONTROL METHOD

PROBLEM TO BE SOLVED: To provide a refrigerant natural circulation jointly used air conditioner capable of cooling operation with an effective natural circulation cycle by stably forming a refrigerant liquid column in a liquid piping connecting a condenser and an evaporator upon cooling operation with the natural circulation cycle. SOLUTION: In a refrigerant natural circulation jointly used air conditioner wherein there are switichable a cooling operation with a compressor freezing cycle and a cooling operation with a natural circulation cycle for circulating a refrigerant with the action of gravity by making use of a phase change of the refrigerant, a refrigerant circuit is formed by connecting a condenser 2 and an evaporator 1 through a liquid piping 15 and a gas piping 16, and there is branched and connected a compressor circuit 19 where a solenoid valve 8, an accumulator 4, and a compressor 3 are disposed in parallel to the gas piping 16, and further a check valve 7 is provided at an outlet of the compressor 3 of the compressor circuit 19.