Thermal transfer behavior in two types of W-shape ground heat exchangers installed in multilayer soils

An experimental and numerical approach to derive ground thermal conductivity in spiral coil type ground heat exchanger

“…The N value of Standard penetration test (SPT) was in a range of 9/30e33/30 in the partially saturated landfill ground. Here, N indicates the number of blows (the numerator) required to penetrate to the desired depth in centimeter (the denominator) [16]. Fig.…”

“…Table 1 summarizes the thermo-physical properties used in the numerical analysis in Incheon city. The material thermal properties were referred from previous studies including the ground condition [16]. For the finite element model, a free tetrahedral mesh was used.…”

“…This was almost similar to the equivalent ground thermal conductivity. The actual equivalent ground thermal conductivity can be calculated using a weighted average method considering each ground layer condition [16].…”

Experimental Verification to Estimate Ground Thermal Conductivity Using Spiral Coil Type Ground Heat Exchangers

“…An analytical equivalent model for multi-layered soil can be achieved using the following equation [8]:…”

Evaluation of thermal efficiency in different types of horizontal ground heat exchangers

“…Considering their high initial cost of construction, there have been many studies [9][10][11][12] aimed at obtaining higher thermal efficiency and lower construction cost of closed-loop, vertical, ground-heat exchangers. Recently, a closed-loop vertical-type GSHP system with an energy-pile foundation was used, in which the GHEs were embedded in cast-in-place grout piles [13][14][15][16].…”