| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a heat exchanger with improved long-term reliability by preventing blocking by scale without impairing performance of the heat exchanger. <P>SOLUTION: In this heat exchanger, the water flows inside an inner pipe 2, carbon dioxide oppositely flows in an annular portion 4a between the inner pipe 2 and an outer pipe 4, a safety double wall is provided, and a sufficient contact area is secured to achieve high heat exchanging efficiency. When the scale is attached to a wall surface 2a of the inner pipe 2, a water temperature is raised and a spiral wire rod 8 made of shape memory alloy is heated to higher than its deformation temperature, thus the spiral wire rod overcomes stress of a bias coil 9, the spiral wire rod slides and rubs the scale attached to the wall surface 2a, and the scale accumulated on the wall surface 2a is separated. The attachment of scale can be automatically controlled to be less than a specific amount with a simple structure, thus the blocking of the inner pipe 2 can be prevented, and the long-term reliability of the heat exchanger 1X can be improved. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
