| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve a problem in a conventional heat exchanger formed by overlapping flat tubes vertically and spirally winding them, wherein a cylindrical space is required inside the spiral part, and there is a lower limit in a radius in winding the tube in spiral shape from restrictions on machining which results in having a limit in reducing the cylindrical space to make space saving difficult. <P>SOLUTION: The heat exchanger for an electric water heater comprises a first fluid passage tube 8 having a first fluid inflow port 8A, a first fluid outflow port 8B, cylindrical piping 8c extending from the first fluid inflow port 8B to the first fluid outflow port 8B and a heat transfer body 8D disposed in contact with the piping 8C inside the piping 8C, and allowing a first fluid to flow inside; and a second fluid passage tube 10 surrounding the first fluid passage tube 8 and allowing a second fluid to flow inside. The heat conductivity of the piping 8C and heat transfer body 8D is higher than that of the first fluid. Either one of the first fluid and the second fluid is water to be heated, and the temperature of the fluid which is not the water to be heated is made higher than that of the water to be heated. <P>COPYRIGHT: (C)2007,JPO&INPIT |
