Thermal performance and energy saving effect of water-loop heat pump systems with geothermal

Abstract

Water-loop heat pump (WLHP) systems are an important option for space conditioning of commercial buildings. They provide the opportunity of saving energy through heat recovery and thermal balancing when heating and cooling occur simultaneously. WLHP systems typically operate with a loop water temperature of between 16 and 32°C. When cooling loads dominate, loop water temperatures are maintained below 32°C by rejecting excess heat with a cooling tower. When heating dominates, loop water temperatures are maintained above 16°C by a heater input. The emphasis of this paper is on the analysis of system performances, energy savings of the mixed cooling and heating mode of the WLHP systems, for it is a unique operating mode in air-conditioning and space heating systems. The energy saving effect by using low temperature geothermal energy as the heat input for WLHP systems was examined.