REFRIGERATING AIR-CONDITIONING DEVICE

PROBLEM TO BE SOLVED: To provide an air-conditioning device of high performance with a refrigerant filled by a regulation value or lower by combining a heat exchanger of high performance with the small amount of refrigerant accumulation and refrigerating cycle technology by using propane and isobutane as a combustible hydrocarbon refrigerant. SOLUTION: In this refrigerating air-conditioning device comprising a refrigerant circuit constituted by connecting a refrigerant pipe for liquid and a refrigerant pipe for gas, connecting a compressor, a four-way valve, a heat source-side heat exchanger, a pressure reducing means, an use-side heat exchanger, an outdoor machine and an indoor machine in a state of a closed loop, and a control means, using the combustible hydrocarbon refrigerant as the refrigerant, and supplying cold/hot heat from the use-side heat exchanger, in-pipe cross-sectional areas of pipes 1, 2, 3 forming an internal refrigerant flow channel of the heat source-side heat exchanger or the use-side heat exchanger are determined so that the in-pipe cross-sectional areas of the pipes 1, 3 at longitudinal end portions are larger than the in-pipe cross-sectional area of the pipe 2 at the longitudinal intermediate portion. COPYRIGHT: (C)2009,JPO&INPIT