Analysis On Influence Of Layered Heat Transfer Model Of Vertical Single U-type Buried Pipe Heat Exchange With Different Seepage Conditions

Ground source heat pump technology is one of the most important ways for energy efficiency in buildings.its basic function is to exchange heat with ground heat exchangers.it discharges heat from soil for building cooling in summer,then takes out the heat for building heating in winter.it can use a small amount of high-taste energy to transfer from low-grade thermal energy to high-grade thermal energy.the system is energy-efficient and environmentally friendly.The study is combination of theoretical and engineering research methods,it was used to establish and validate a vertical single U-shaped ground-tube heat exchanger delamination heat transfer model considering the geological stratification and different seepage conditions,in-depth analysis of heat exchange in the ground tube The actual heat transfer characteristics of the device under different seepage conditions(no seepage,horizontal seepage,vertical seepage,backfill vertical seepage,3D groundwater seepage).The main research results are as follows.(1)Ground source heat pump systems with horizontal seepage seepage have the highest heat transfer,followed by vertical seepage.Compared with the seepage seepage in the horizontal direction and the seepage in the vertical direction,the heat exchange capacity without seepage increased by 103.85% and 60.26%.It can be seen that the groundwater seepage can significantly affect the heat exchange capacity of the ground heat exchanger,and the horizontal seepage seepage is particularly significant.(2)Horizontal seepage heat transfer changes with the change of seepage direction.The heat transfer amount in the direction perpendicular to the inlet and outlet pipes is the highest in the upstream seepage direction,followed by the upstream direction of the inlet pipe and the outlet pipe in the upstream direction.(3)The groundwater seepage in the backfill material can increase the heat exchange capacity of the buried pipe and increase with the increase of the seepage velocity of the backfill soil.Especially when there is horizontal seepage in the external soil,the effect is very significant,followed by vertical seepage of the external soil.(4)The 3D groundwater seepage model is more advanced,more realistic,and more precise than other models.The results show that the heat transfer performance is best when the temperature is 15°.When the seepage velocity exists in both the horizontal and vertical directions,the effect of horizontal seepage is greater than that of vertical seepage.Therefore,when there is vertical seepage,the faster the horizontal seepage seepage,the lower the outlet water temperature and the higher the heat exchange amount.