| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a water heater comprising a plate heat exchanger capable of securing reliability similar to an air conditioner by calculating a condensing temperature inside of the plate heat exchanger on the basis of a pressure of a refrigerant discharged from a compressor and controlling the water heater by a method same as a conventional control method of the air conditioner. <P>SOLUTION: In this water heater provided with a refrigerating cycle constituted by successively connecting a compressor 1 with variable operation capacity, a four-way valve 2 for switching the direction of the refrigerating cycle, the plate heat exchanger 10 for exchanging heat between water and a refrigerant, an electronic expansion valve 6 for controlling a flow rate of the refrigerant to reduce the pressure, and a heat exchanger 9 for exchanging heat between air and the refrigerant by a pipeline to circulate the refrigerant, a pressure detection means Pd is disposed between the outlet of the compressor 1 and the four-way valve 2 for detecting the pressure of the refrigerant discharged from the compressor 1, and the operation speed of the compressor 1 is controlled according to the difference between the condensing temperature calculated from the pressure detected by the pressure detection means Pd and a target condensing temperature. <P>COPYRIGHT: (C)2009,JPO&INPIT |
