Initial Commissioning of a Water-to-Water GHP System in KIER

Abstract

GHP(Geothermal Heat Pump) system has been extensively disseminated due to the recent increasing demand of the new and renewable energy in Korea. However, the system reliability issues have been key barriers to ensure system performance as initially designed. This paper introduces a systematic method to verify its actually operating performance of a water to water GHP system. The main idea is to compare the actual performance with the manufacture data and then to reduce the gap between the actual and the manufacture data. The key result of this study is the development of a simplified GHP performance verification technique using the ISO standard based manufacture data. The manufacture performance data includes the information of EWT(entering water temperature), LWT(leaving water temperature), capacity, flow rate, power and COP. This technique has been verified to a w to w GHP system designed and installed at KIER site. The verification study showed that actual performance was lower than Manufacture data. And then the refrigerant was recharged and the compressor and the expansion valve were replaced. As a result, we can easily identify the GHP system problems and heating and cooling COP has been increased 25.26%, 18.24%.