Vertical U-tube Ground Source Heat Pump New Backfill Process

As energy consumption of China growing fast and increasing international energy tensions, Chinese government promulgate the energy saving and emission reduction policy. Because ground source heat pump is a energy saving technology, so it has been promoting and using. But for saving more energy people still research how to increase heat-transferring amount in per unit depth of well in engineering using.In this paper, research how to decrease hot short-circuit situation between the two pipes of the vertical U-tube heat exchanger. A numerical simulation is used, the GAMBIT software was used to establish the vertical U-tube heat exchanger with or not with the heat insulation baffle's geometrical models, and use the FLUENT software to simulate this two models. Use the similarity theory to establish a model test bed, through this bed we can verify numerical simulation's credibility.Through the models the vertical U-tube heat exchanger outlet water temperature in the summer and winter situation can be known, and then we can know that heat-transferring amount of the vertical U-tube heat exchanger with the heat insulation baffle is more 2.74% and 3.0% than which without in summer and winter situation. Set the different heat conductivity of the heat insulation baffle, then through the simulation we can know that when the heat conductivity of the heat insulating material in the national regulation extent, the heat insulation baffle's heat conductivity's change has very small influence on the U-tube's heat-transfer ability.This dissertation aims to decrease hot short-circuit situation between the two pipes of the vertical U-tube heat exchanger, because it can increase heat-transferring amount in per unit depth of well(reinforce ability of the U-tube's heat-transfer). Provide a theoretical basis and technical support for the ground source heat pump system promotion and application in China.