Design And Implementation Of Testing System For Geotechnical Thermophysical Property

The shortage of energy drives the green and environmental-friendly energy enters the period of rapid development.The ground-source heat pump technology has become a popular cooling / heating technology.With the wide application of the ground-source heat pump,more and more attention has been paid to the development and utilization of shallow geothermal energy.The geotechnical thermophysical property is a basic data type that must be used in the development of shallow geothermal energy.And it is very important for designing ground-coupled heat exchanger.A geotechnical thermophysical property testing system is designed and implemented in this work.The majority of works are summarized as follow.First,the system's requirements have been analyzed mainly according to the investigation of current businesses in the ground source heat pump technology testing center in Hebei Province.Starting from the specific characteristics of the geotechnical thermal property testing work,the system can be divided into three parts including integrated control module,parameter acquisition module and data storage module.The integrated control module mainly deals with the electrical system,human-computer interaction,running state and so on.Through the programming control,the parameter acquisition module mainly deals with the data acquisition of each working module by the 485/232 communication protocol.Meanwhile,the use of frequency conversion technology in the integrated control module to adjust the load,reduce power consumption,reduce loss,prolong the service life of the equipment and so on.Secondly,through the three-layer architecture technology,continuous heating or cooling by artificial cold/heat source was successfully implemented.After the testing of rock and soil's initial temperature is settled,the integrated control system started to record the rate of temperature change and circulation flux.Meanwhile,the parameters of each functional module are displayed in the human-computer interaction interface through the programming control.Thirdly,depending on the ground-source heat pump test-bed of the Energy Research Institute of Hebei Academy of Sciences,four operation cycles were completed in the stable operation by connecting the test system separately to the ground source side of the test-bed.After obtaining the typical test data,it was applied into the data model on test bed to simulate the ground source heat pump model which was designed according to the recommended values.The simulated model was then compared with the actual measurements and simulated values from heat pumps under winter cooling situations to verify the scientificity of the test system.Finally,after many verifications of the system by the test-bed,it has been put into use in many practical business projects of ground source heat pump in which the test system has sufficiently showed scientificity and reliability.It not only provides scientific reference and technical support for the design of ground-source heat pump project,but also brings considerable economic benefits for Hebei Academy of Sciences.