Design And Implementation Of Flue Gas Mercury Sampling System Based On STM32

Mercury pollution has attracted global attention, which mainly comes from coal-fired emissions. The coal consumption in our country is huge, the environmental pollution caused by mercury has become increasingly prominent. In order to effectively control and manage the emission of mercury from coal combustion, it is necessary to carry out accurate monitoring or sampling analysis of mercury in flue gas. Only accurate measurement of the total amount of mercury in flue gas, finding out the distribution of mercury in different forms and the quality of the each parts and the migration and accumulation of mercury in the natural environment, can establish the reasonable mercury pollution control laws and regulations be established, and make correct meaningful evaluation on human health and the environment protection etc.The Mercury Sampling System in this topic is designed based on the U.S. EPA 30B method. The system is designed to use of solid sorbents to capture the mercury in the flue gas, and calculates the flue gas volume according to the flowmeter, then quantitative analysis for the mercury which is captured by solid sorbents are made by professional mercury analyzer, thus obtains the sampling concentration of mercury in the flue gas. The system comprises a sampling gun assembly, a control panel and a heat tracing pipe connecting the two before. The control panel includes a control circuit with STM32F103ZET6 as a control chip, and a flue gas processing device. The whole sampling system works under the control of the control circuit in order. The sampling operation and control can be carried out by the display screen and the button, and the whole sampling process is clear, and the sampling result is automatically stored or printed.The system software adopts modular design thinking, which is divided into 5 modules:sensor data acquisition module, alarm and parameter setting module, data storage module, user terminal module and the main program module. The functions of sensor data acquisition, sampling parameters setting, LCD display, the results of the storage of the data storage, querying for historical data, etc are realized through the main program module. so as to achieve the function of the entire system.In the performance contrast test of the Mercury Sampling System, the performance contrast test of adsorption tube and the overall system were carried out respectively. The test results of the comparison between the system and the contrast of the equipment are not large, it is the error range, and both of them meet the quality control requirements and accuracy requirements of EPA 30B.