PURPOSE: To always suitably hold superheat degree in a suction part of a compressor and to increase an operating range by providing means for connecting an intermediate-pressure conduit to a low-pressure conduit via a tube through a heat source side expansion valve between one heat source unit and a plurality of using units.
CONSTITUTION: A plurality of using units 7 are connected in parallel with one heat source unit 6 through a high-pressure conduit 12, a low-pressure conduit 13 and an intermediate-pressure conduit 14. In this case, at the time of overheat operating, for example, the units 7, a throttling amount of a using side first expansion valve 9 (K) of the unit 7 (K) of a non-maximum thermal load except except the unit 7 (J) of maximum thermal load is regulated, and a condensing amount of a using side heat exchanger 8 (K) is reduced as compared with that of a using side heat exchanger 8 (J). A throttling amount of a heat source side second expansion valve 15 of the unit 6 is regulated, refrigerant of the conduit 14 is sucked in a suitable amount to the conduit 13, thereby suitably holding refrigerant superheat degree in a suction part of a compressor 1.
FUNAKURA SHOZO
NAKATANI KAZUO
TAGASHIRA MINORU
| JPH04103970A | 1992-04-06 | |||
| JPH0359362A | 1991-03-14 |