A Study On The Soil Temperature In A Hybrid Ground Source Heat Pump System With Supplementary Cooling Tower

Cooling-dominated commercial and institutional buildings served by ground-source heat pump (GSHP) systems generally reject more heat to a closed ground-loop heat exchanger (GLHE) than they extract over the annual cycle. This imbalance may result in a significantly larger GLHE than would be required for a system with annually balanced heat rejection and extraction. So-called hybrid GSHP system may utilize supplemental heat rejecters (such as cooling towers, fluid coolers, cooling ponds) to reduce system first cost and to improve system performance. The use of supplemental heat rejecters for cooling-dominated building allows the use of smaller borehole fields. Degradation of the heat pump performance is avoided by offsetting the annual load imbalance in the bore field. Moreover different control strategies and different operational parameter significantly affect the operation performance of HGSHP. A comparative study is presented that investigates restoration of the soil temperature in a hybrid ground-source heat pump experiment system with cooling tower.A physical and dynamic mathematical model of the HGSHP system which includes the HGSHP unit, air conditioning terminal, GLHE and supplement cooling tower are made based on Energy conservation law, On the basis of above, a steady-sate mathematical model and a program on R134a are made, especially in the influence of ground temperature, Which is the foundation of the determination of control strategies on HGSHP.In the experiment hybrid ground source heat pump system with supplementary cooling tower which had been set up, the cooling capacity of the heat pump unit with R134a scroll compressor is 21.8Kw at the ARI standard condition. The data collection and control systems can meet the demands of the hybrid ground source heat pump experiments at different seasons and various operation conditions. The experiment HGSHP on interdigitate pause operation have been finished which based on the experimental existed equipments. Experimental results analysis is conducted on the restoration of the soil temperature.