| 摘要 |
The present invention relates to a heat exchanger in which welding areas are increased in a connection portion between a heat exchange tube and a tube-fixing plate, as well as in a connection portion between the tube fixing plate and a flow channel cap, so as to more firmly fix a tube connection portion, and the gap between tubes is minimized to increase the heat transfer areas of tubes, thereby maximizing heat exchange efficiency. For this purpose, the heat exchanger of the present invention comprises: a plurality of tubes which are arranged in parallel to each other and equidistantly from each other, such that cooling water passes through the inside of the tubes, wherein each of the tubes has an elongate-hole-shaped cross-sectional surface in which the width of the side contacting combustion gas is greater than the height thereof; and tube-fixing plates coupled to both ends of each of the tubes so as to fix the tubes at a predetermined spacing. Each of the tube-fixing plates has a plurality of elongate fixing holes corresponding to the shape of the tube, and each of the fixing holes has an edge having a protrusion vertically formed toward the tube connection side, such that an inner surface of the relevant tube is brought into contact with an outer surface of the protrusion, and an end of the relevant tube is brought into contact with a flat portion of the tube-fixing plate. |
