PURPOSE: To reduce thermal stress generated in a tube plate upon welding a side shell and prevent the leakage of fluid by a method wherein both side surfaces of the tube plate are provided with stepped structures circumferentially around the outer periphery of welding parts different from a site whereat a water side shell is welded to a refrigerant side shell.
CONSTITUTION: A shell-and-tube type water side heat exchanger is manufactured by a method wherein tubes 5 are connected to a tube plate 2 by expanding process and, then, a shell 1 and a side shell 3 are welded to the tube plate 2. Upon the welding, a thermal stress is applied on the tube plate 2, however, a stepped structure is provided around the outer periphery of the welding part different from the welding parts of the shell 1 and the side shell 3 and the thickness of the structure is thickened whereby the thermal stress, transferred to the connecting part between the tubes 5 and the tube plate 2, is reduced and the welding of the shell 1 and the side shell 3 can be effected without reducing a contact resistance between the tubes 5 and the tube plate 2. According to this method, the leakage of fluid through the expanded parts of the tubes 5 can be prevented.
IZUSHI MINETOSHI
AOYAMA MITSUGI
NISHIDA SHUICHI
