PURPOSE: To improve and stabilize heat efficiency by constructing a heat transfer fin with an extrusion molding material and constructing the same integrally with a heat transfer partition wall, and further providing the heat transfer fin so as to be larger on the side of the heat transfer partition wall and make uniform the thickness of the heat transfer fin.
CONSTITUTION: High temperature gas produced in a combustion chamber 10 passes through a combustions gas outlet 13 and further passes through between heat transfer fins 22A, 22B of high temperature gas passages 12A, 12B and flows from exhaust passages 25, 26 to an exhaust pipe 24. Further, inner walls 14 of the high temperature gas passages 12A, 12B construct many fins and passages. And, fin thickness on the side of a heat transfer partition wall 11 is made larger and fin thickness of the inner wall 14 side is made thinner. And, the inner walls 14 and the heat transfer fins 22A, 22B are integrally constructed with an extrusion molding material provided to be uneven in its thickness, whereby a heat transfer area per unit area is increased. Further, with a double wall construction where the inner wall of the high temperature gas passage 12 is constructed with a combustion chamber 10 and it is constructed with the outer peripheral heat transfer partition wall 11 and a refrigerant passage member 15 in close contact with the former, heat is transferred from the inner wall to the heat transfer fins 22A, 22B, so that heat transfer efficiency is improved, and remaining outer surface other than the inner wall 14 in contact with the high temperature gas passages 12A, 12B of the combustion chamber 10 is covered with a heat insulating material 23 for prevention of heat radiation.
YAMAMOTO KATSUHIKO
OHASHI TADAYOSHI
TAKAYAMA MINORU
SHOWA ALUMINUM CORP