| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a water heater capable of suppressing sharp decline in compressor performance even when a temperature of water introduced to a water heat exchanger is lowered and of performing efficient operation over a condition in a wide range. <P>SOLUTION: The water heater includes: a refrigerating cycle 3 formed by interconnecting a two-stage compressor 7 having an injection port P between a low stage and a high stage, a first gas cooler 9, a second gas cooler 11, a first flow control valve 13 and an air heat exchanger 15 by refrigerant piping 19 so as to make a refrigerant flow sequentially; a water cycle 5 having water piping 37 wherein water is made to flow from the second gas cooler 11 through the first gas cooler 9 and heat exchange is performed with a refrigerant made to flow in the first gas cooler 9 and the second gas cooler 11; and an injection circuit 21 branched from a branch point A between the first gas cooler 9 and the second gas cooler 11 in the refrigerant piping 19, merged at a merging point B between the first flow control valve 13 and the air heat exchanger 15 and supplying the refrigerant to the injection port P. <P>COPYRIGHT: (C)2011,JPO&INPIT |
