A comparison of analytical and numerical model predictions of shallow soil temperature variation with experimental measurements

Estimation of In-Situ Heat Capacity and Thermal Diffusivity from Undisturbed Ground Temperature Profile Measured in Ground Heat Exchangers.

“…From that so-called damping depth, the wave of the oscillatory surface temperature begins a linear attenuation with depth in the interval located before the thermostatic zone (Figure 2). A practical approximation ratio is used to evaluate the damping depth by considering the depth where the surface temperature amplitude is reduced to e -1 (1/2.718 = 0.37) of its initial value [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][39][40][41]. Beyond the approximation ratio approach, several other mathematical equations have been proposed to evaluate the damping depth.…”

“…The method is based on the evaluation of the annual amplitude temperature decay and the annual damping depth during a long-term observation of the ground thermal disturbance diffusion resulting from the annual thermal flux at the ground surface [24,27,28]. Often, one-dimensional semi-analytical to analytical solutions or numerical simulations are used to infer the ground TD with various methods, such as the amplitude ratio, the phase lag, and the harmonic method [10,[21][22][23][24][27][28][29][30]. Despite the potential of these approaches to provide in-situ evaluation of TD, they appear hardly applicable to the design of ground-coupled heat pump systems.…”

Application of the Superposition Technique in Conduction Heat Transfer for Analysing Arrays of Shallow Boreholes in Ground Source Heat Pump Systems

“…However, studying arrays of boreholes is challenging due to the complexity of modelling the interference of multiple boreholes in a defined volume, and this complexity increases when dealing with shallow boreholes as the ground cannot be treated anymore as an undisturbed medium. In fact, the ground close to the surface is highly affected by the ambient fluctuations in the short-term (hourly or sub-hourly basis) and the long-term (seasonal variations) [2]. Accurate analytical models have not been developed for this kind of systems.…”

Thermal Analysis of an Earth Energy Bank

“…The PVT collectors coproduce electricity which is fed directly into the grid, and heat which is put into the ground via the GHE. The concept of storing thermal energy in the ground using GHEs has been studied by many such as [2], [3] & [4], however, the depths of these boreholes are usually in excess of 10 m. The peculiarity of the design in this study is in the very shallow depth, which makes it susceptible to the effects of ambient conditions [5].…”