The aim of this study is to evaluate the characteristic thermal properties of 208 (thermal response test) TRT data sets collected in Korea. In the evaluation, the line-source model is used in conjunction with the step-wise evaluation to validate the applicability of the model. The...

This paper presents a numerical and experimental study on the evaluation of borehole thermal resistance with TRT (thermal response test) and TPT (thermal performance test) results observed in closed-loop vertical type boreholes with U and W type GHEs (ground heat exchangers). Field TRTs were...

The ground thermal conductivity and borehole thermal resistance are essential parameters for the design of a ground source heat pump system. As it is hardly possible to obtain sufficiently accurate values of these parameters from geological or soil-profile information, thermal response tests...

Ground source heat pump systems often use closed-loop heat exchangers, which depend on the soil thermal conductivity and borehole thermal resistance as parameters. An in-situ thermal response test provides a method to estimate these two parameters. In analyzing the in-situ test, one commonly...

Ground source heat pump systems are often coupled to the ground by circulating a fluid through vertical Borehole Heat Exchangers (BHEs). The design of a system requires estimates of the ground thermal conductivity and the borehole thermal resistance, which are usually determined by an in situ...

This study presents experimental and numerical research results in determining an effective borehole thermal resistance of a spiral coil energy pile. A precast high-strength concrete (PHC) energy pile with a spiral coil GHE was installed and thermal response test was carried out to evaluate the...

In groundwater-filled borehole heat exchangers (BHEs) convective flow influences the heat transfer in the borehole. During heat extraction thermal response tests (TRTs) the effect of the changing convective flow is more dominant than during heat injection tests. Water is heaviest around 4 °C...

Borehole Thermal Energy Storage systems typically use U-pipe Borehole Heat Exchangers (BHE) having borehole thermal resistances of at least 0.06Km/W. Obviously, there is room for improvement in the U-pipe design to decrease these values. Additionally, there is a need for methods of getting more...

Thermal performance of vertical U-pipe borehole heat exchanger (BHE) is an important research subject for the design and application of ground-coupled heat pump system (GCHPs). This paper presents an improved evaluation method for thermal performance of BHE based on analytical solution model,...

Energy piles have recently emerged as a viable alternative to borehole heat exchangers, but their energy efficiency has so far seen little research. In this work, a finite element numerical model is developed for the accurate 3D analysis of transient diffusive and convective heat exchange...