Research On Heat Transfer Law And Influencing Factors Of Energy Pipe In Deep Pile Type

In recent years,the shallow ground thermal energy development is increasingly widely used by the ground source heat pump technology,wherein the ground-source sub-underground thermal structure is the frontier topic of geothermal development research.In this paper,a new deep pipe type of energy pile structure is proposed based on the buried pipe energy pile inside the pile,which uses the high heat transfer performance of concrete structures to achieve higher heat transfer efficiency than traditional drilling tubes,and has played a deep layer.The thermal storage capacity of the bury tube is high;and a large number of drilling costs can be saved and fully utilized underground space resources.This technology,the economic advantage is obvious,and the purpose of energy saving and emission reduction is achieved.This paper first introduces a new deep pipe type of energy pile structure,starting from the heat transfer structure and heat exchange mechanism of the energy pile,by carrying out heat transfer testing of deep pipe type of energy pile and combined with numerical simulation,deep buried Research on the heat transfer law of tubular energy piles and changes in heat exchange,the main work and research results are as follows:(1)Combined with the research status of energy piles at home and abroad,the main problems of energy piles and the research value of new deep pipe type of energy pile were analyzed.The heat transfer test is carried out on the deep pipe type of energy pile of the energy pile site,and the temperature distribution law of deep pipe type of energy pile is studied.When the heat exchange reaches stable,the temperature of the water pipe relative to the temperature of the water pipe is more obvious,wherein the upper pile foundation portion of the water pipe temperature is the fastest,and the temperature change of the water pipe temperature is not large;the temperature change of the lower deep well part Small than the pile foundation,the temperature change of the water pipe is also small.(2)Using the ANSYS software to establish a deep pipe type of energy pile dual u-type buried tube heat exchanger model consistent with the experimental site,compare the field test and simulation results of the energy pile removal process,the actual test result in the depth direction The results of temperature distribution and numerical simulation result,numerical simulation and field tests verify the accuracy of the model.When the heat is transferred to stabilization,the heat of the upper pile is larger than the lower deep well,and when the pile foundation is excessive to the deep well,the heat affects gradually decrease.(3)The overall structural heat exchange efficiency of energy piles under different conditions can be calculated from the analysis results,and the lower deep well portion heat exchange is higher than the upper pile foundation,but the portion heat exchange efficiency of the pile foundation is higher than the deep well portion.Adding the flow rate and pile length of the circulation medium can effectively improve the overall heat transfer of deep buried energy piles,and the heat exchange efficiency is also higher.In short,this paper will analyze the temperature distribution law through deep pipe type of energy pile,analyze the temperature distribution law,and explore the heat transfer performance under heating(summer)working conditions,and study the heat transfer mechanism of deep pipe type of energy pile.This paper will provide the theoretical basis for the application of new energy piles,promoting further improvement of energy pile technology,and makes a positive contribution to the utilization of geothermal energy.