Buride Heat Exchanger Factors Affecting Temperature Field And Recovery Law Research

Ground source heat pump is a kind of Refrigeration Air Conditioning Technology and it can via a ground heat exchanger to exchange heat with the soil around.With the gradually shortage of the earth's energy,this technology becomes increasingly popular throughout the world.Therefore,more experts ramp up research on ground source heat pump.Buried pipe heat exchanger absorbs a large amount of heat from the soil,which will lead to cold heat imbalance in the soil that can have a bad impact on the long-term operation of the ground source heat pump.This paper is based on the vertical u-shaped underground buried tube heat exchanger as the research object,you can set up a model which is consist to the actual object with Gambit and setting the division of grid and boundary conditions.Then set of energy equation through the Fluent software solver.To run the buried pipe under the condition of no seepage and seepage to see change of soil temperature field and analysis the change of temperature field around the buried pipe in these two different operation period.On the basis of buried tube sheet heat exchanger and the surrounding soil temperature heat transfer,we can simulate a nest of tubes,then analysis the influence of soil temperature field after heat exchange with different factors on the nest of tubes.Finally,selecting a certain office building of siping area,through the TRNSYS for dynamic load simulation,and then design the ground source heat pump,simulating the soil temperature change in one year and five years after double season or single season running,and summarizes the rules.By simulating,it can be found that single pipe run without seepage the ground source pump after a year of heat exchange operation,will be slightly lower than the initial temperature.It can be found that when single pipe run seepage the ground source pump after a year of heat exchange operation,the temperature of the soil can return to the initial temperature.If the thermal conductivity coefficient of backfill materials are higher,the heat transfer will become correspondingly more conducive.It also has an advantage for the recovery of soil temperature at the same time.But when it higher than the heat conductivity coefficient the effect is not obvious,so when buried pipe of backfill materials should consider the coefficient of thermal conductivity of the soil at the same time.The thermal efficiency is better when a nest of tubes cross compound heat transfer,but the interaction between soil pipe and tube is relatively large,so the exhaust pipe layout to comprehensive all aspects of the factors to consider.When the influence of seepage velocity is taken into consideration,with the increase of flow velocity,soil temperature recovery will be better.When the seepage is not considered and the soil was seen as a porous medium,with the increase of soil porosity,the fluctuation of soil temperature variation will be smaller.The ground source heat pump after double season running,the soil temperature reduce amplitude is small,but running in winter or summer,the extent of soil temperature is lower or higher,this is not conducive to the long-term running of ground source heat pump.In this paper,through the simulation of the temperature field around the buried pipe,we can get the influence of different factors,it can also provide theoretical reference in the engineering design of ground source heat pump.