JPS6438595A - Heat exchanger - Google Patents

Abstract

PURPOSE:To improve an efficiency of thermal conductivity without making an axial larged-sized water pipe and without narrowing a fin pitch by a method wherein thermal conducting fins are partially projected to form a plurality of projections. CONSTITUTION:A heat exchanger A is composed of a plurality of thermal conducting fins 1... arranged in parallel in every desired spacing over a rightward or a leftward direction of a combustion cylinder B, and a plurality of water pipes 2... passing through these fins at a right angle and fixed to them. Each of the thermal conducting fins 1 is of a flat copper plate having a superior thermal conduction, has a plurality of round through-holes 1a... through which the water pipes 2 are inserted with a proper spacing, each of hole edges is burred and at the same time they are partially projected to form a plurality of projections 1b.... A surface area of each of thermal conducting fins is expanded by an amount corresponding to a plurality of projections, a flow of combustion gas between the thermal conducting fins is disturbed by the projections to increase the Reynolds number, so that it is possible to improve the efficiency of thermal conduction without enlarging the axial size of water pipe or narrowing a fin pitch.