Study On Operating Performance And Dynamic Simulation Of Ground-Coupled Heat Pump System

Ground-coupled Heat Pump (GCHP) system is becoming the more and more focus of the world's attention as a HVAC technique of energy saving and environment protection. GCHP technology, especially in heating, has become maturity in USA,German,Sweden and so on. At present, there is a lack of the fundamental study of its dynamic performance and the situation of its energy saving potential in China. Therefore, it is important to investigate its component performance and the application issues. For this purpose, a research on GCHP system is carried out theoretically and experimentally in this paper.According to the hydrogeology in Tianjin and user's practical demand, a GCHP experiment system with two different underground heat exchangers of stake-buried tube and Vertical U-tube is established based on the former experimental data of single U-pipe underground heat exchanger. Aim at the system, we research and develop a device of computer Supervisory Control and Data Acquisition (SCADA), which can meet the auto-acquisition demands of the GCHP system in different seasons and various modes. On this condition, experiments on operation property of the GCHP were conducted in winter and summer respectively. The coefficient of performance and characteristics of the GCHP cycle are analyzed and summarized. To analyze performance of single-compressor in water source heat pump(WSHP), the theoretical study on single-compressor are carried out with the thermodynamics analysis. On the basis of above, a steady-state mathematical model and a program on R22 are made to simulate the operating process of the WSHP, In order to gain operating performance of GCHP at different conditions.A physical & dynamic mathematical model of the GCHP system with the mechanism modeling method are made. Besides, fuzzy control method are applied in the system. Ultimately, dynamic operating simulation programs are made with the help of Matlab/Simulink. The model can be used to simulate operation of the GCHP system with surroundings disturbance continuous variation. It is different from tradition simulation of skip variety of disturbance or startup mode of heat pump. And it is verified by the experiment results of the GCHP system.