Study Of Soil Thermal Properties Baesd On The Transient Plane Heat Source Method

With the increasing use of energy and environmental pollution increasingly serious,people urgently need a clean energy without polluting the environment under the premise of both heating and cooling,ground source heat pump technology can be a good solution to this problem.However,the design of ground source heat pump needs to consider the thermal and physical properties of soil,so it is very important to accurately measure the thermal and physical parameters of soil.Thesis based on the national natural science foundation of China youth science fund project “Study of the impact of geological and hydrological conditions to the energetical efficiency of ground source heat pump systems”,carry out the related research.It analyze the characteristics of shallow buried pipe ground source heat pump technology and point out its broad application prospect of development on the basis of introducing of shallow geothermal system.It generalize the measurement method of soil coefficient of thermal conductivity,and expounds the measuring principle of the transient plane heat source method.It analysis the influence factors of thermal physical parameters of soil,which provides the important basis for subsequent test soil of thermal physical parameters;We make a experiment scheme about soil thermal parameters combined with the above presentation,and make a the soil thermal conductivity test under different influencing factors.On the basis of summarization and analysis on the results of the experiment,we analyze the application of ground source heat pump from Taian.Soil coefficient of thermal conductivity factors affecting the experimental results show that:(1)The soil thermal conductivity and soil water content and dry density are positively related,and the water content have a greater influence on soil thermal conductivity,dry density have little influence.But,it is not along with the growth of the water content.When the water content reaches to a certain extent,the coefficient of thermal conductivity of growth began to slow.The influence of dry density on soil thermal conductivity coefficient of variation is not obvious.With the increase of dry density,soil coefficient of thermal conductivity increased slowly.(2)The coefficient of thermal conductivity is associated with soil types.Soil test results showed that the sandy soil and clay has the highest thermal conductivity when the ratio of 2:1 from the test.(3)have a negative correlation with the depth of ground water level.With the increase of depth of ground water level,soil coefficient of thermal conductivity will decrease.Thesis discuss the technology in detail,and make a test and analysis about the soil coefficient of thermal conductivity under different influence factors.The research of the paper provide a valuable reference for the application of ground source heat pump technology.