Numerical Simulation Of Heat Transfer Characteristics Of Buried Pipe Under Stratified Seepage

Via a buried pipe heat exchanger,the ground source heat pump system exchanges heat with the earth below the ground.The ground source heat pump system’s working efficiency is largely dependent on how well the buried pipe heat exchanger performs heat exchange.In actual geological settings,the stratification of rock and soil will be noticeable;in some places,the stratification of subsurface water may also be visible.Thus,it is vital to research how variable seepage qualities,depending on the vertical stratification of rock and soil,affect the heat transmission characteristics of buried pipes under complex geological settings.This gives buried tube heat exchanger design in actual engineering a theoretical foundation.The research object in this paper is an underground vertical U-shaped buried tube heat exchanger.Using Fluent software,a three-dimensional model of the individual well and well group heat exchanger is created,and the model’s accuracy is confirmed.The single well model was used to examine the impacts of seepage condition(with or without seepage),seepage velocity,and soil porosity on the heat transfer properties of buried pipes.The impacts of groundwater seepage direction,pipe configuration,and intra-pipe flow rate on the functionality of the heat exchanger in the tube group were examined based on the well group model.The findings demonstrate that groundwater seepage helps buried pipe heat transmission.The heat transmission of a double U-shaped underground pipe heat exchanger rises by 17% when there is seepage in the rock and soil layer compared to the situation without seepage.The performance of the underground pipe’s heat transfer increases accordingly with the rate at which the rock layer seeps fluid.The double-U pipe’s capacity to transport heat improves by 20.23% as the seepage velocity rises from50 m/y to 200 m/y.According to this study,underground pipes’ ability to transfer heat would diminish as soil porosity rises.However,the attenuation range is narrow,and when soil porosity ranges from 0.2 to 0.5,the capacity of buried pipes to transport heat drops by 1.1%.The heat transfer of the buried pipe group increases by 2.9% in oblique seepage compared to vertical seepage when the effect of seepage direction on heat transfer performance is taken into account.Without taking into account the buried pipe group’s area,it is discovered that when the percolation direction and pipeline arrangement mode are fork row and oblique flow,respectively,the buried pipe group has the highest heat exchange and the buried pipe has the best heat exchange performance.The percolation direction is oblique flow when the area of the pipe group is taken into account,and the pipe arrangement mode is sequential.The tube group has the greatest heat transmission per unit area;The ground source heat pump system’s pump power consumption rises when the flow rate in the pipe group rises from 0.6 m/s to 1.2 m/s,increasing the heat transfer of the buried pipe group by 74.8%.When the flow rate in the pipe is between 0.8 and 1.0 m/s,the heat/power ratio of the ground source heat pump system is found to be at its highest.This is taken into account when taking into account the influence of the heat transfer of the pipe group and pump power consumption.Fig.40 table 8 Ref.82...