A wet-bulb temperature-based control method for controlling the heat balance of the ground soil of a hybrid ground-source heat pump system

Abstract

Hybrid ground-source heat pump system has been widely used for mitigating the heat accumulation problem of conventional ground-source heat pump systems. This article proposes a wet-bulb temperature-based control method for a hybrid ground-source heat pump system which comprises a ground-source heat pump and a conventional water-cooled chiller using a cooling tower. With this method, the operation priority between the ground-source heat pump and the water-cooled chiller is determined according to the outdoor wet-bulb temperature. A TRNSYS platform of the system is developed, and simulations are carried out to investigate the system performance under the proposed control method. Meanwhile, simulations with two other control methods (reference methods), that is, the ground-source heat pump-prioritized method and water-cooled chiller-prioritized method, are also conducted. The study results show that the proposed control method has obvious advantage in controlling the heat balance of the ground-source heat exchangers, and in the meantime, no more energy is consumed when compared with the two reference control methods.