PURPOSE: To provide a high performance heat transfer element for a heat exchanger high in heat transfer rate and low in pressure loss per unit length.
CONSTITUTION: Large waves 1 are formed with waves having edge lines of an angle A of 5 to 20° relative to the flow direction of entering fluid which are intermittently provided in the flow direction of the entering fluid at pitches 75 to 125 times the height eL of a large wave and whose slanting faces have an angle of not less than 30 relative to a plane parallel to a line connecting the crests of the waves. Small waves 3 are provided between the large waves 1 and have height lower than the large waves 1. The large waves 1 and the small waves 3 are intermittently provided at pitches 50 to 100 times the height es of the small wave 3 in the flow direction of an entering fluid. A heat transfer surface in which the slanting face of the small wave 3 has an angle C of not less than 10° relative to a plane parallel to the a connecting the crests of the waves and a heat transfer surface having a symmetrical shape to the former heat transfer surface relative to the plane parallel to the line connecting the crests of the waves thereof are alternately laminated to obtain a hydraulic diameter of 7 to 8mm of a fluid passage formed between the laminated heat transfer surfaces.
MIYAGAWA JUNICHI
KAWABUCHI IKUYA
MATSUO ATSUJI
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