PURPOSE: A hot water generating device using a heat pump is provided to prevent frosting by keeping working fluid at uniform low pressure, even if it is winter or temperature of waste water decreases. CONSTITUTION: A hot water generating device using a heat pump comprises a compressor(10), a first heat exchanger, a second heat exchanger, a third heat exchanger, a first expansion valve and an evaporator(40). The second heat exchanger is installed in a water supply pipe(52) and the working fluid which is within a transfer pipe(41) connected to the compressor from the evaporator is evaporated through the second heat exchanger according to the selective operation of an electronic valve(34). The third heat exchanger is installed between a transfer tube body(22) connected to the first expansion valve from the first heat exchanger. A second expansion valve is installed between transfer tube bodies(28,31) in inlet or outlet sides of the third heat exchanger. The working fluid is converted into the gas of low temperature and low pressure according to the selective action of a solenoid valve(27) and transferred to the compressor.
展开▼
