Simulation investigation on pre-cooled heat pipe (PCHP) for free cooling of high thermal density space

Abstract

High thermal density space consumes massive energy, and cooling device accounts for large percentage of total consumption. To cut down energy consumption of cooling device, PCHP is proposed on the basis of heat pipe and evaporation technologies. Heat transfer and energy consumption models of PCHP are developed. The effects of geometric and operational parameters on the PCHP performance, including pad thickness, ambient temperature and ambient relative humidity (RH), air flow rate, are investigated. The results show that cooling capacity increases with the increase of pad thickness and airflow rate, and it decreases with the increase of ambient temperature and RH. With the increase of thickness, energy efficiency ratio (EER) increases at the start and then decreases under RH20%-40%, while it decreases continuously under RH70%-90%. EER increases with the decrease of ambient temperature, ambient RH and air flow rate. PCHP markedly enhances annual free cooling time compared with conventional heat pipe system (CHP), and the maximal enhanced free cooling time and increasing percentage occur at Urumchi and Guangzhou Cities, respectively.