ASHRAE 지열교환기 설계법에 대한 전역 민감도 분석

Ground heat exchanger (GHE) is a critical component of ground-source heat pump systems. One of the most common GHE types is borehole heat exchanger (BHE). The determination of the required BHE length is influenced by many uncertain parameters, including the ground thermal load, ground thermal properties, and BHE geometry. The ground thermal load is influenced by the building loads and heat pump efficiency, which can vary widely. Spatially averaged ground thermal properties inherently involve uncertainty. Furthermore, the construction process for BHEs cannot be entirely controlled. The propagation of parameter uncertainties throughout the sizing process results in a significant level of uncertainty in estimating BHE length. Therefore, this study aims to quantify the contribution of each input parameter to BHE sizing, elucidating their impacts on BHE sizing uncertainty. The results exhibited that the 1-hour peak ground load and 720-hour-long peak ground load are the most influential factors contributing to BHE sizing uncertainty. Consequently, the results suggest that prioritizing uncertainty management of parameters related to ground load is essential to enhance the reliability of BHE design.