Numerical Analysis of Open-loop and Closed-loop Geothermal Heat Pump Systems

Abstract

A choice between a closed-loop and an open-loop geothermal heat pump (GHP) system is not simple. The closed-loop system is more reliable and requires less maintenance in the long-term operation. The open-loop system is more energy-efficient and simple. However, the initial costs of the closed-loop system are comparatively high and the open-loop system is practical only where there is an adequate supply of relatively clean groundwater. The performance and efficiency of the system depend on geologic conditions and cooling and heating loads besides the types of systems. In this study, three different types of systems (the vertical closed-loop system, two-well open-loop system, and standing column well system) are examined at various geologic conditions and cooling and heating loads. The performance of the three-types of systems is analyzed for a year operation simulation results.