Study On Leakage Detection And Diffusion Settlement Of Pulverized Coal In Coal To Gas Process

The raw coal used in the process of coal gas production is mostly pulverized coal particles with small particle size,high volatile matter,low moisture content and low ash content,and its lower explosive limit concentration and ignition temperature are both low.The coal-to-gas process involves a high-temperature and high-pressure environment.Once leakage occurs,once it spreads,it is very easy to cause an explosion accident,which seriously affects the safety of the coal-to-gas industry.Through the study of the detection of pulverized coal concentration and the law of diffusion and sedimentation,the safety monitoring of the coal-to-gas process and the location of the source of pulverized coal leakage have been realized,providing effective technical support for emergency handling of accidents.In view of the study of pulverized coal leakage detection and diffusion and settlement law,the following work has been mainly done:1.Describes the current status and technological process of coal-to-gas development at home and abroad,and further analyzes the causes of pulverized coal leakage,the status quo of detection of pulverized coal concentration and the development of pulverized coal diffusion and sedimentation laws,and conducts research on this background.2.Starting from the overall system structure,the overall system structure is constructed.The system hardware design is introduced from the sensor network system coordinator,routing node and sensor terminal node.The three parts of the sensor array,the pulverized coal collection device and the control module are mainly designed in detail..By introducing the protocol stack to Zigbee,it is the software development environment of the main tools,and then the overall design of the system software is carried out around the corresponding hardware framework.According to the overall design and hardware structure,from the coordinator node program,the routing node program and the terminal sensor The specific software is introduced in three aspects of the node program,and the verification method for networking is given.3.Analyze the movement mechanism and kinetic model of pulverized coal particles.During the sedimentation process,the sedimentation rate of pulverized coal reaches the end-of-settlement rate within a short period of time,and the difference between theoretical calculations and measured data is small,indicating that theoretical calculations are used to analyze coal.The pulverized sedimentation rate is feasible.Under the action of different mechanical forces,the distance of horizontal movement of pulverized coal particles has little relationship with the mechanical force received,mainly because it is related to the flow velocity of the surrounding air,and gravity can be ignored.4.According to the mechanism of pulverized coal diffusion and sedimentation in the air,a Gaussian mist and rain model based on turbulent diffusion is established,and the location of the source of pulverized coal leakage is studied,and it is applied to the non-linear least square method and the maximum likelihood method.A kind of pulverized coal leakage source that uses Gaussian mist and rain model and sensor nodes to obtain the best linear unbiased estimation of the concentration value is presented.Gaussian plume diffusion is used to establish a measurement model for the position of each node,the measurement model is linearized,and then the Taylor series is used to expand,through the optimal linear unbiased estimation of the location of the pulverized coal leakage source,multiple iterations to obtain the optimal leakage source The best estimate of the location.