| 摘要 |
PROBLEM TO BE SOLVED: To minimize high temperature water flowing into the return passage 46 side from a by-pass passage 44 when supplying hot water to heaters 50, 60 in a method of cutting down cost and to ensure sufficient by-pass flow during the stop of hot water supply. SOLUTION: The by-pass passage 44 is provided with a fixed throttle means 47. When supplying hot water to the heaters 50, 60, the quantity of high temperature water flowing into the return passage 46 side from the by-pass passage 44 is reduced due to high pressure loss. During the stop of hot water supply, sufficient by-pass flow can be ensured because there is no other way than flowing through the fixed throttle means 47, which can prevent a service life from being shortened by applying high load to a secondary side circulating pump 42. Furthermore, the method of providing the fixed throttle means can cut down cost because of needing neither detecting means for detecting a hot water supply state nor a control means for controlling them. COPYRIGHT: (C)2005,JPO&NCIPI |
