24 June 2014

Development of the building integrated geothermal system with the horizontal heat exchanger

Ground source heat pump systems can achieve the energy saving of building and the reduction of CO2 emission by utilizing annually stable ground temperature. However, they have barriers for wide-spread such as high cost of installation, incompletion of design tool, lack of recognition as heating and cooling systems, so on. In order to solve the problems, the building integrated geothermal system (BIGS) has been developed by several
researches which use building foundation as heat exchanger. In the study, in order to establish the optimum design tool of BIGS with the horizontal heat exchanger, the prediction method of ground heat exchange rate was developed with numerical simulation model. The
developed model was coupled with ground heat transfer model, ground surface heat model and ground heat exchanger model. Furthermore, case studies were conducted in the various
conditions of design and installation, in which the depth of installation, space between pipes and the diameter of pipe were considered. In the results, it was found that the case of diameter 32 A, piping space 0.3 m and flow rate 9.52 L/min was the best case as 15.0 W/m of heat exchange, rate in case studies. Moreover, the heat exchange rate of all cases according to operation, conditions was calculated by the long-term simulation.