The effects of antifreeze in the circulating water on the operation performance of ground heat exchangers
Xiuqin Yang1, Xiang Zhou1, Xu Zhang1.
1School of Mechanical Engineering, Tongji University, Shanghai, People's Republic of China
Ground-coupled heat pump (GCHP) systems often require antifreeze in the circulating water in locations with significant heating seasons, such as Northern China. In this study, the effects of antifreeze in the circulating water on operation performance of ground heat exchangers (GHEs) was investigated. A theoretical model was derived to analyze the antifreeze effect. Then the model was validated by an experimental system. Based on the effects of antifreeze solution on heat transfer performance and friction loss, the correction factor of flowrate and friction loss are given. In addition, the design method for GHEs in cold regions are also discussed.