초록 ▼

Two outdoor units (2A, 2B) are connected in parallel to a main liquid line (7L) and a main gas line (7G). Three indoor units (3A, 3B, 3C) are connected in parallel to the main liquid line (7L) and the main gas line (7G). The outdoor units (2A, 2B) are each provided with an oil equalization mechanism

Two outdoor units (2A, 2B) are connected in parallel to a main liquid line (7L) and a main gas line (7G). Three indoor units (3A, 3B, 3C) are connected in parallel to the main liquid line (7L) and the main gas line (7G). The outdoor units (2A, 2B) are each provided with an oil equalization mechanism (9A, 9B) for conducting a surplus out of lubricating oil stored in an oil reserving part (91) provided on the discharge side of a compressor (21) to the suction side of a compressor (21) of another outdoor unit (2A, 2B). In cooling operation, the respective oil equalization mechanisms (9A, 9B) control respective gas bypass passages (95, 96) and respective oil equalizing bypass pipes (93, 94) to open and close them so that lubricating oil flows alternately between the outdoor units (2A, 2B), thereby equalizing lubricating oil. In heating operation, the respective oil equalization mechanisms (9A, 9B) control the respective oil equalizing bypass pipes (93, 94) to open and close them so that lubricating oil flows alternately between the outdoor units (2A, 2B) and hold the downstream sides of the oil equalization mechanisms (9A, 9B) in low pressure condition, thereby equalizing lubricating oil.

대표청구항 ▼

For use with an air conditioner comprising: a plurality of thermal source units each having at least a compressor and a thermal-source-side heat exchanger; a main liquid line to which the plural thermal source units are connected in parallel with each other; a main gas line to which the plural therm

For use with an air conditioner comprising: a plurality of thermal source units each having at least a compressor and a thermal-source-side heat exchanger; a main liquid line to which the plural thermal source units are connected in parallel with each other; a main gas line to which the plural thermal source units are connected in parallel with each other; and a user unit which has at least a used-side heat exchanger and which is connected to the main liquid line and the main gas line, in which refrigerant discharged from the compressor is condensed by one of the heat exchangers, is expanded by the expansion mechanism and is then evaporated by the other heat exchanger, an oil equalizing operation control device comprising oil equalization mechanisms for conducting lubricating oil stored in an oil reserving part provided on the discharge side of the compressor of each of the thermal source units to the suction side of the compressor of the other thermal source unit wherein the compressor has an oil discharge mechanism for discharging, when lubricating oil stored in the compressor exceeds a set amount, the excess of lubricating oil, and the oil equalization mechanisms each conduct only surplus lubricating oil above a set amount out of lubricating oil stored in the oil reserving part to the suction side of the compressor of the other thermal source unit.