Development Of In Situ Thermal Desorption On-site Meteorological Monitoring Device

In recent years,in situ thermal desorption technology has been rapidly developed and applied in the remediation of organic contaminated sites.During the remediation of contaminated soil using in-situ thermal desorption technology,on-site meteorological data can provide strong data support for secondary pollution prevention,equipment operation and process index control,improving the quality and efficiency of contaminated soil remediation.At present,traditional meteorological monitoring devices are unable to meet the new requirements of the environmental protection sector for in-situ thermal desorption site meteorological monitoring and management,and to accurately monitor and control in-situ thermal desorption site construction operations.Therefore,this paper designs and develops a meteorological monitoring device for application in in situ thermal desorption sites.Firstly,the device adopts STM32 as the core processor to complete the control of hardware modules and processing of monitoring data,designed digital filtering algorithm and long-range radio(LoRa)communication circuit with SX1278 as the frequency radio chip respectively,to realize the real-time acquisition and uploading of six types of meteorological elements in the in-situ thermal desorption site,which improves the data monitoring accuracy and communication stability of the device.Secondly,designed the upper computer monitoring interface based on Configuration King,which realizes the monitoring of on-site meteorological data,querying and downloading of historical meteorological data to facilitate the monitoring of on-site meteorological data.Finally,to solve the impact of changes in environmental humidity on the in-situ thermal desorption process and secondary pollution prevention,this paper proposes to build a humidity prediction model based on an improved recurrent neural network(RNN),improve the parameters of the model by combining the problems that arise during the experiments while solving the problem that the traditional RNN cannot remember for a long period of time,and make use of OPC(OLE for Process Control)technology to complete the invocation of the prediction model in the monitoring interface of Configuration King,realize the regional refinement of the prediction of the humidity of the in-situ thermal desorption site.The test of the weather monitoring device shows that the maximum error of the device on temperature,humidity,wind speed,wind direction and Total Volatile Organic Compounds(TOVC)concentration,which are 0.3℃,2%,0.3m/s,3° and 0.2mg/m3 respectively.The maximum relative error of PM10 concentration is 5%and the full-load power consumption of the device is 1.52W.The error,power consumption and stability of the device all meet the design requirements.