Condensation Heat Transfer Characteristics According to Heat Transfer Tubes and Operating Conditions in Condensers for Absorption Chillers

An experimental device was constructed to investigate the heat transfer phenomenon of condensers for absorption chillers. Three condenser samples with different types and diameters of heat transfer tubes were prepared to examine the effect of the shape of the tubes. These condenser samples were evaluated under various operating conditions with different temperatures and flow rates of cooling water and refrigerant. When the temperature changed by the same amount, the effect of the condensation temperature of the refrigerant on the heat transfer rate of the condenser was generally greater than that of the cooling water inlet temperature. Corrugated tubes had an average 5.86% greater heat transfer rate than plain tubes, and 19.0-㎜ diameter corrugated tubes had a 2.76% greater heat transfer rate than 15.9 ㎜ diameter corrugated tubes. Changes in the heat transfer coefficient and Nusselt number outside the tube were also investigated in each experimental condition.