Research On The Heat Probe And Soil Properties Test

With the development of industry and the continuous consumption of resources,the world is facing more and more serious energy crisis.Energy-saving has become the main theme of world's economic,technological and social development.Reasonable use and exploitation of geothermal energy is one of the important ways to solve the energy problem,while,rapid and accurate access to soil thermal properties is a prerequisite for sustainable development of geothermal energy.This paper is based on the National Natural Science Foundation of China:Study on Thermal Response Mechanism and Analytical Method of Energy Piles Based on Multi-function CPTU(51578146).This paper develops a kind of heat probe and heat transfer mode which can measure soil thermal conductivity of in situ.This paper conducted and in situ test of thermal response test in Jiulonghu campus of Southeast University,the heat transfer characteristics of different soil layers were analyzed with the influence of temperature change on the in situ mechanical properties of soil was discussed.The main research results are as follows.1.Based on the infinite heat source heat transfer model,a heat conduction probe which can measure the thermal conductivity of in situ soil was developed,and also the size,material and heating power of the heat conduction probe were optimized.The heat conduction probe is 100cm high,the outer diameter is 4.4cm,and the heating power 200W.2.The numerical calculation model of heat transfer probe was established by using Comsol numerical analysis software.The calculation method of thermal conductivity of soil was established based on temperature dissipation formula.The experiment of indoor calibration experiment was conducted to contrast heat transfer probe and thermal probe under laboratory experiment.3.The thermal response test of soil was carried out in Jiulonghu campus of Southeast University.The thermal conductivity of soil was tested by self-made thermal conduction probe,and the results were compared with those of indoor thermal probe.The effect of temperature variation on the lateral friction and cone tip resistance of the soil was discussed under the different temperature.The results showed that the temperature had some properties on the in situ mechanical properties of the soil and the degree of its impact and soil...