Research And Development Of Stratified Thermal Response Stratification Test Technology And Its Application

Shallow geothermal energy can be used as a sustainable energy for the 21st century,it comparable to the use of value of solar energy,wind energy.In recent years have been more widely used at home and abroad.The heat transfer performance of the ground heat exchanger in the ground source heat pump technology plays a decisive role in the efficiency of the ground source heat pump system,often used thermal response test to carry out the design of the buried heat exchanger.The thermal response test is mainly to obtain the soil thermophysical parameters,so the accurate access to soil thermophysical parameters indirectly affects the ground source heat pump system.In this paper,domestic and foreign thermal response testing technology and thermal response equipment were analyzed,Independent research and development of the stratigraphic thermal response stratification test equipment its advantage lies in:(1)On the basis of the theory of online heat source,the application model of stratified thermophysical parameters is deduced,and the model was used to verify the performance of the thermal response test instrument at the test area.(2)The instrument in addition to achieve the temperature,flow,power and other basic parameters of the precision test,also joined the stratified temperature measurement equipment,to achieve the integration.And joined the remote monitoring and transmission system,in the test site unattended failure through the text message to inform the experimental staff,and can remotely transmit the monitoring data to the terminal.(3)Stratigraphic thermal response stratification test equipment can monitor the temperature of each floor of the buried pipe,can be calculated stratified thermal conductivity,stratified per meter heat transfer.And can be used to analyze the intermittent running soil heat transfer capacity.For the temperature measurement cable and fiber field data obtained by the temperature measurement cable can be better applied in the stratified temperature,and found that changing the heating power has little effect on the stratified thermal conductivity,increasing the influent temperature can significantly improve the heat transfer of rock and soil at each depth.The rationality of the stratified test method is proved by comparing the numerical simulation with the measured results,According to the different depth of the pipe to get the heat transfer and drilling costs were found,existence of ideal heat transfer formation and ideal heat exchanger depth.Therefore,through the thermal response stratification test more effective guide to the design of the buried pipe heat exchanger tube length,in order to save drilling costs.