Study And Calculation On The Experiment Of Layer Shallow Soil Thermal Properties Ofground Source Heat Pump

Shallow Ground Source Heat Pump (GSHP) system is mainly use of the thermal energythrough shallow subsurface soils, and has attracted much attention because it does not pollutethe natural environment and applicable to any area in theory. Currently, the system is mainlyused to provide heat and provide cooling for the building in summer and winter. The differentsoil thermophysical properties in different regions and the diverse underground soil structure inthe same area have both important influence to run complex soil shallow ground source heatpump system regulation.It makes the heat transfer performance is decided by groundwaterseepage location, flowability, flow rate and etc. The diversity of soil structure and thecomplexity of the heat transfer make the calculations not accurate, which leaded that the heatpipe can not be determined and the natural temperature changes in the environment also have aneffect on surface temperature. How to accurate design of shallow ground heat exchanger pipeby determining shallow subsurface soil thermophysical properties becomes a difficult problemtolimit GSHPdevelopment.Firstly, the paper introduce the development of shallow GSHP system and analyze theadvantages and characteristics of shallow GSPH technology, noting it has broad prospects fordevelopment. Introduce GSHP technology for underground soil survey methods and points outdeficiencies. Propose soil thermal properties test, the underground soil is divided into severallayers, design and build the soil thermal properties of thermal testing experimental platform anddetailed description the test platform, and conventional soil thermal testing and sub-experimentstation layer of soil thermal properties test. Finally, the numerical simulation model for thelayered soil thermalphysical properties was established basing on cylindrical heat source model.The thermal conductivity, the heat capacity per unit volume and the heat transfer resistance arecalculated by Matlab, and the difference of data analysis is compared and the reasons of thedifferencesareobtainedThe soil thermal properties, mainly is thermal conductivity and heat capacity per unitvolume have great influence for GHSP system, the more of thermal conductivity and heat capacity per unit volume, the better of heat exchange efficiency between heat exchanger andground, and have useful of de geothermal energy. Text to the soil thermal properties through thelaboratory method and the line heat source model and the column heat source model and thelayer of column heat source model of The field test method and analysis of the result. Thethermal conductivity through the layer of column heat source model is deviation as high as39.71%to the laboratory method and11.74%to the line heat source model and7.13%to thecolumn heat source model. The heat capacity per unit volume and the backfill material throughthelayer of column heat sourcemodel is deviation as high as14.37%and30.47%to the columnheat source model. And the layer soil thermal properties can refine the different depth of soillayer underground, won’t be affected by objective factors such as natural environment and moreobjectively describes the distribution of thermal physical real underground soil and undergroundwaterdistribution.Given all this, the test of layer shallow soil theraml properties and calculation model canaccurately calculate the soil thermal properties such as thermal conductivity and heat capacityper unit volume, make the ground with good heat exchange more useful and to reduce the Soilthermal imbalance of GSHP system to run for a long time. Research to provide the referenceand basis of the after study.