To minimize the number of functional components required to switch an operation mode to a minimum limit and to improve operating efficiency to a maximum limit.
A single cooling mode is detected by an operating mode means Mode. An air side heat exchanger 3 is operated as a condenser, a first refrigerant to water heat exchanger HE1 is operated as an evaporator, and a second reversible expansion valve EV2 is operated as a throttle mechanism. First, second and third reversible expansion valves EV1, EV2, EV3 are controlled in opening by an expansion valve control means EVcnt to conduct a chilled water generating operation at a refrigerant side of the exchanger HE1. A first two-way valve V1 and a second two-way vale V2 are controlled to be opened or closed by a two-way valve control means Vcnt. An opening of the valve EV2 is optimally controlled so that a differential temperature of the refrigerant inlet and outlet of the exchanger HE1 falls within a predetermined differential temperature range, thereby achieving the performance of the exchanger HE1 to a maximum limit.
MACHIDA KAZUHIKO
HAMADA KAZUYUKI
MATSUSHITA MASAO
KIMURA MASAO
NAT HOUSE IND
KANSAI ELECTRIC POWER CO