| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a heat exchanger small in size and excellent in reliability and a heat pump water heater using the heat exchanger. <P>SOLUTION: This heat exchanger 10 comprises first and second heat transfer tubes 1 and 2 involving a first flow passage 3 in which a first fluid flows and a second flow passage 4 in which a second fluid flows. These heat transfer tubes are wound spirally. The second heat transfer tube 2 is disposed doubly on the inside of the wound first heat transfer tube 1. Also, the structure of the second heat transfer tube 2 is applied to the heat pump water heater. By this, the mounting density of the heat exchanger can be increased and a storage space for the heat exchanger can be minimized by effectively utilizing a space formed on the inside of the spirally wound heat transfer tube, and the heat exchanger small in size and excellent in storability thereof in equipment can be provided. In addition, the heat transfer tubes can be easily increased in length, and an increase in performance and capacity of the heat exchanger can be easily realized. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
