STUDY ON OPTIMIZATION OF DESIGN AND OPERATION FOR GROUNDWATER HEAT PUMP SYSTEM BASED ON REAL-SCALE EXPERIMENT AND NUMERICAL SIMULATION

The groundwater heat pump (GWHP) system is an open-loop system that draws water from a well orsurface water, passes it through a heat exchanger and discharges the water into an injection well ornearby river. By utilizing the relatively stable temperature of groundwater, this system can achieve ahigher coefficient of performance and offers a more energy-saving solution than the conventionalair-source heat pump (ASHP) system. On the other hand, its performance significantly depends on thecharacteristics of the groundwater and the underground thermal properties. In order to optimize thedesign and operation of a GWHP system, it is necessary to develop a comprehensive method bearingin mind subterranean heat flow and building conditions. This paper describes the optimization of aGWHP system based on an air-conditioning experiment utilizing real-scale equipment and 3Dnumerical heat-water transfer simulation. In 2006, cooling and heating experiments were conductedusing two wells for production and return. Furthermore, a numerical simulation model was developed topredict the amount of heat exchange with the groundwater under different underground and buildingconditions. Analysis results were compared with the experimental results, and the validity of thesimulation model developed in this study was confirmed.