| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a heat pump water heater with improved heat exchange efficiency and with reduced number of heat transfer tubes and reduced usage of refrigerant. <P>SOLUTION: The heat pump water heater comprises: a refrigeration cycle constituted by annularly connecting a compressor, a water-refrigerant heat exchanger, an expansion mechanism, and an evaporator sequentially by refrigerant pipes, and a fan sending air to the evaporator. The evaporator is constituted of a plurality of rows of heat exchangers constituted of heat transfer tubes and plate finns, to run the refrigerant from the leeward heat exchanger to the windward heat exchanger, a cross-sectional area of the leeward heat exchanger tube is smaller than the cross-sectional area of the windward heat transfer tube. <P>COPYRIGHT: (C)2009,JPO&INPIT |
