JPS6458995A - Fintube type heat exchanger - Google Patents

Abstract

PURPOSE:To elongate the time of space heating operation which can be continued until its stop caused by the clogging with frost layers by a method wherein a heat exchanger is composed of a fin group and plural row of heat transfer tube groups inserted into the fin group with right angles and in heat transfer tube groups the number of heat transfer tubes in the front row with regard to the air flow direction is brought into a specific ratio of the number of the heat transfer tubes in the rear row. CONSTITUTION:The number of the heat transfer tubes of a group 12 in the front row with regard to the air flow direction 14 is made to be 20-70% of the number of the heat transfer tubes of a group 13 in the rear row. Since the pitches of the tube group 12 in the front row are made larger, the fin efficiency of a fin group 11 is lower in the front row and fin temp. is high at the side of air inflow. Consequently, the deposited amount of frost per unit time in the front row with regard to the air flow direction can be made almost equal to that in the rear row and air passing area without the deposited frost among the fins can be made nearly uniform in the range from the side of air inflow to the side of air outflow and space heating can be elongated largely.