CLM calculates among other parameters, the absorption, reflection and transmittance of solar radiation, the absorption and emission of longwave radiation, the surface colour variability, the surface albedo, the sensible heat, the latent land surface heat fluxes, the heat transfer in soil and snow and the atmosphere surface coupling (Neale et al. 2012).
The land model used was the Community Land Model (CLM), which has atmosphere-surface coupling, surface colour variability, surface albedo calculation, absorption, reflection, and transmittance of solar radiation, absorption and emission of longwave radiation, sensible heat (ground and canopy) latent heat fluxes and heat transfer in soil and snow [23].
The effects of soil density, a solar hot water system and volume of hot water dropping flow rate on heat transfer in soil, depth level and working time were tested in comparison with solarization.
Underground heat can be exploited through a heat transfer between soil and heat exchangers of different types and sizes.
In order to clarify the definite seasonal difference, an indirect moisture, heat and dynamic coupled model of embankment in permafrost regions is deduced on the basis of principal theories of numerical heat transfer, physics of frozen soil, frozen soil mechanics and soil dynamics, meanwhile, its corresponding numerical program is also developed.
The heat transfer mechanisms in soil are conduction, convection, and radiation.
This formulation is based on the discretized diffusion equation of heat transfer through the soil column.
The model includes the Penman Monteith evapotranspiration equation, long wave radiation, short wave radiation, sensible heat transfer (convection) and soil heat flux.
The three-dimensional version of the model accounts for heat transfer in the soil and for heat and moisture transfer along the underground pipe.
Consequently, by carefully controlling the design parameters of the pipeline it is possible to control the heat transfer to the soil and the temperature drop along the pipeline.
