Novel Heat Pipe Assembly for Enhanced Thermal Performance of Air-Cooled Condenser

A significant constraint in enhancing the heat transfer efficiency of air-cooled condensers is the limited installation space, which necessitates the use of compact condensers that are often cost-prohibitive. To address this, the present study investigates a novel approach: integrating a heat-pipe assembly with an air-cooled condenser to augment its thermal performance. In this configuration, multiple heat pipes are installed within the condensing liquid reservoir at the base of the condenser and extended along the outer surface of the radiator fins. The thermal performance of the air-cooled condenser, both in its conventional and modified forms, was numerically investigated under various design and off-design ambient temperatures. Design conditions were set at an ambient air temperature of 35 °C and a fan mass flow rate of 6.8 kg/s, utilizing R134a as the refrigerant with a mass flow rate of 0.34 kg/s, a saturation temperature of 49.7 °C, and a condenser outlet temperature of 43.5 °C, resulting in a heat rejection rate of approximately 59.6 kW. The results demonstrate that the heat-pipe assembly significantly enhances the heat transfer performance of the base condenser, although the magnitude of improvement diminishes as ambient temperature rises. Specifically, the modified condenser exhibited a percentage improvement in heat transfer ranging from 2.5 to 3.4% as the ambient temperature varied between 15 and 35 °C.