Research On Reliability Of Slag Water Treatment System Of Coal Water Slurry Gasifier

Coal,as a traditional power raw material,plays a role in many fields such as industry and science and technology,while coal water slurry gasifier pushes the utilization rate of coal to a high point.CWS fuel is composed of pulverized coal,water and additives,and its advantages of low pollution and high utilization rate are fully reflected in the production process.At the same time,because of the fluid characteristics of CWS,the transportation is more simple and convenient.As a typical coal gasification process,coal water slurry gasification reacts with oxygen to obtain crude syngas composed mainly of hydrogen and carbon monoxide,which provides clean energy for related industries.Since its birth,coal gasification technology has developed by leaps and bounds in the past 20 years.Large-scale coal gasification equipment will inevitably be accompanied by failures in the high-intensity and long-time operation,which will bring great harm and loss to personal safety and production.Therefore,it is particularly important to carry out risk analysis on the important system of coal gasification device.The slag water treatment system,as the core component of coal gasification unit,has not made outstanding achievements in risk analysis,especially in dynamic risk analysis.A risk analysis model based on Bayesian network combined with AHP method and fuzzy comprehensive evaluation method was proposed to solve the problem of lack of systematic analysis in the current risk analysis of gasification slag water treatment system.According to the actual operation of a coal chemical enterprise with a daily coal input capacity of 3000 tons gasifier as the research object,the AHP method and fuzzy comprehensive evaluation method were applied to carry out the model hierarchical risk analysis,and the causes of each deviation in the analysis results were transformed into Bayesian network nodes.In consideration of the lack of prior knowledge,the Leaky Noisy OR model is introduced.The prior probability is obtained by searching relevant literature and expert experience knowledge,and the risk analysis is carried out by using Bayesian network to find the weak links in the operation process of the system.At the same time,a risk analysis method based on dynamic Bayesian network for slag water treatment system of gasification furnace was put forward in view of the deficiency of dynamic risk analysis in the current large-scale gasification unit.The decision tree model was established based on the failure data of each unit in the gasification slag water treatment system,and the decision tree model was transformed into a Bayesian network model.The Bayesian network model was optimized by simulated annealing algorithm,and the influence of common cause failure on the system was treated by combining with theβ-factor method.Considering the influence of maintenance hazard factors on the system failure rate at each moment,the Bayesian network analysis software Genie was used to calculate,and the accuracy and feasibility of the proposed method were verified by Monte Carlo method at last.It can provide a theoretical basis for identification of weak links in operation of large coal gasification equipment.