REFRIGERANT CIRCULATION TYPE AIR-CONDITIONING SYSTEM

摘要

PROBLEM TO BE SOLVED: To prevent the excessive feed of a refrigerant to an outdoor machine during low load operation of an indoor machine and to prevent the occurrence of defective operation and the increase of an amount of a necessary refrigerant. SOLUTION: A refrigerant circulation type air-conditioning system effects circulation of refrigerant steam from the heat-exchanger of an outdoor machine 1 arranged at an elevated place during heating operation to the heat-exchangers of a plurality of indoor machines 3. A liquid reservoir tank 18 to receive refrigerant liquid is arranged in a position lower than that of the indoor machine 3 and a pump 6 is located in a refrigerant liquid pipe 5a running from the liquid reservoir tank 18 to an outdoor machine 1. A liquid lever switch 19 is arranged at the liquid reservoir tank 18. The pump 6 is controlled such that the liquid level of a refrigerant in the heat-exchanger of the outdoor machine 1 is maintained in a given range by the output of the liquid level switch 19. During load operation of the indoor machine 3, a pump operation prohibition time after a stop of a pump is set during low load operation of the indoor machine 3. A pump operation prohibition time is set such that the prohibition time during a stop of combustion is set to a value longer than that during combustion of the outdoor machine 1.