Simulation And Experimental Study Of Heat Transfer Characteristic Of Earth-to-air Heat Exchanger

Earth-to-air heat exchanger makes use of single or multiple pipe buried in theground to gather solar energy,which was accumulated in the shallow soil. When theair flows in the underground pipe,it can make the air temperature get down/warmingin the summer/winter due to the temperature difference between the air and theground. Through the pretreatment of the fresh air,it can greatly reduce the building’senergy consumption of air conditioning.The system design includes: air velocity,pipe length, depth and diameter.In order to analyze different factors that affects theperformance of earth-to-air heat exchanger, numerical models or experiment platformare established. But for the latent heat effect on earth-to-air heat exchange system, andthe dehumidification performance of the system, few of people studies.In this thesis, a two-dimensional steady-state numerical model is establishedusing FLUENT software.Through the UDF, achieving the condensation phenomenonin the process of heat exchange,the dehumidification performance of earth-to-air heatexchanger is analyzed.Through the calculation to model, it is concluded that thesystem has certain dehumidifying ability, but the dehumidifying effect still not meetthe minimum requirements of indoor air moisture content, needing otherdehumidification equipment for further processing.Meanwhile, in this thesis, the morerealistic three-dimensional non-steady-state numerical model are studied. The airtemperature at the entrance and soil temperatures at different depth, all using UDFload fitting function to the FLUENT software solver.To verify the accuracy of themodels, an earth-to-air heat exchanger in Tangshan city was monitored, and comparedwith simulation results. Results show that the error is less than1℃, and model isavailable.This paper has a certain guiding significance on the earth-to-air heatexchanger in our country’s application.