Study of functioning of heat exchanger in soils with different thermal diffusivity

О. S. Kovyazin

Abstract


It was found with the help of mathematical model of the process of heat exchange between the air moving in vertical heat exchanger and the massif of soil, which connects energetic factors of the soil heat exchanger with its parameters as well as natural-climatic conditions that effective thermal energy during the term of heat exchanger functioning depends linearly on thermal diffusivity of soil both for separate heat exchanger and for two heat exchangers located at 4m between axes. Calculative experiment was conducted with application of the packet of calculative hydrodynamics ANSYS Fluent. Temperature field of the air being cooled and of the massif of soil has been detected for the soils with different thermal diffusivity. It has been found that temperature diffusivity of the soil is a determinative factor of energy potential of soil and has a dramatic effect on the effective thermal capacity especially for long-term functioning of soil heat exchanger. From the soil with temperature diffusivity 2,68 m2/s  we can obtain approximately 3,6 times as more effective thermal energy while heat exchanger is functioning than from the soil with temperature diffusivity 0,83 m2/s.


Keywords


surface layers of the Earth; thermal energy; soil heat exchanger; thermal diffusivity of the soil

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DOI: https://doi.org/10.24028/gzh.0203-3100.v40i2.2018.128938

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