Numerical modeling of slinky-coil horizontal ground heat exchangers

Fujii, Hikari; Nishi, Keita; Komaniwa, Yoshihito; Chou, Naokatsu

doi:10.1016/j.geothermics.2011.09.002

Cited by 106 publications

(58 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The heat flux resulting from an algebraic summation of the listed fluxes qcond is transported into the ground (mainly by conduction) or in the opposite direction, depending on its minus/plus sign. The heat balance on the surface of the ground taking into account convection, radiation, and moisture evaporation has the following form [13][14][15][16][17][18][19][20][21]:…”

Section: Heat Balance On the Surface Of The Groundmentioning

confidence: 99%

Undisturbed Ground Temperature—Different Methods of Determination

2017

View full text Add to dashboard Cite

Methods for the calculation of the undisturbed ground temperature (UGT) are presented. Heat fluxes occurring on the surface of the ground and their influence on the UGT are described. Correlation equations for the calculation of the undisturbed ground temperature based on the meteorological data averaged in the yearly cycle are proposed. These equations are of a semi-empirical character and they are based on the heat flux balance. The determined coefficients of these equations, particularly the convection heat transfer coefficient, are consistent with the values specified by other methods.

show abstract

Section: Heat Balance On the Surface Of The Groundmentioning

confidence: 99%

Undisturbed Ground Temperature—Different Methods of Determination

2017

View full text Add to dashboard Cite

show abstract

“…Researchers at the Department of Earth Resources Engineering at Kyushu University in Japan [10] checked various configurations of slinky-type horizontal heat exchangers. They checked heat exchangers with a loop diameter of 0.8 m, pipe diameters of 0.034 m and 0.024 m and with a spacing of 0.4 m, 0.6 m and 0.8 m; in order to assess the heat-transferring process between the soil and the heat exchanger pipes they used the ratio Δt/q τ , where Δt = /t k -t 0 / (K), t k (°C) is the average temperature of the heat-transfer fluid, t 0 (°C) is the temperature of the reference soil measured at a distance of at least 5 m from the heat exchanger and at the same depth as the heat exchanger, and qτ (W·m ) is the specific thermal output of the ground source heat exchanger.…”

Section: Open Accessmentioning

confidence: 99%

Temperatures and Heat Flows in a Soil Enclosing a Slinky Horizontal Heat Exchanger

2014

View full text Add to dashboard Cite

Abstract:Temperature changes and heat flows in soils that host "slinky"-type horizontal heat exchangers are complex, but need to be understood if robust quantification of the thermal energy available to a ground-source heat pump is to be achieved. Of particular interest is the capacity of the thermal energy content of the soil to regenerate when the heat exchangers are not operating. Analysis of specific heat flows and the specific thermal energy regime within the soil, including that captured by the heat-exchangers, has been characterised by meticulous measurements. These reveal that high concentrations of antifreeze mix in the heat-transfer fluid of the heat exchanger have an adverse impact on heat flows discharged into the soil.

show abstract

“…In the ground heat exchanger application, the heat storage capability of soil is exploited to increase the efficiency of the traditional heating, ventilation and air conditioning (HVAC) systems. This was demonstrated by many research works either experimentally or numerically [3].…”

Section: Introductionmentioning

confidence: 77%