Research On Degradation State Recognition,Life Prediction And Maintenance Strategy Of Gasifier Firebrick Based On HSMM

The firebricks are located inside the combustion chamber of the gasifier and are subjected to the impact of high temperature and pressure,the erosion of acidic gases and the washing of slag in a high temperature molten state due to the gasification reaction.As a key component of gasifier,the residual life of the firebricks determines the performance and operation safety of gasifier.In order to ensure the performance and safety of gasifier,it is necessary to make a reasonable maintenance strategy for firebrick to ensure that the residual life of the firebricks is within a healthy range.In order to ensure that the maintenance strategy is timely and reasonable,it is necessary to focus on the accurate recognition of the degradation state of firebrick and the accurate prediction of the residual life,which is of great engineering significance to develop the maintenance strategy of firebrick reasonably,so as to ensure the safety of gasifier operation and greatly reduce the maintenance cost.Aiming at the problem of degradation state recognition and residual life prediction of gasifier firebrick,this thesis analyzes the degradation law and causes of gasifier firebrick,and carries out relevant research based on Hidden Semi-Markov Models(HSMM).The main contents of the thesis include:(1)The process of coal water slurry gasification and the composition of coal water slurry gasifier and the composition of firebrick in combustion chamber are summarized,and the degradation trend and main reasons of firebrick in gasifier are analyzed.(2)The basic theories and algorithms of Markov and Hidden Markov Models(HMM)are summarized,and the basic theories and related algorithms of HSMM are introduced on this basis.Finally,the methods and steps of degradation state recognition and residual life prediction of gasifier firebricks based on HSMM are proposed and introduced in detail.(3)The HSMM-based firebrick degradation recognition model and residual life prediction model were used to study the firebrick of a coal water slurry gasifier in a company,and the comparison between the model and the actual value was conducted to verify the effectiveness and applicability of the proposed method.The degradation coefficient K is introduced to improve the original model of firebrick residual life prediction based on traditional HSMM,and the comparative analysis of the results verifies the superiority of the improved model.(4)The degradation state recognition results and residual life prediction results of gasifier firebricks obtained based on HSMM were analyzed,the degradation law of gasifier firebricks was summarized,and constructive suggestions and new solutions were put forward for the reasonable development of gasifier firebrick maintenance strategy in the actual production process.On the premise of imperfect maintenance,preventive maintenance strategies are developed for each degradation state of gasifier firebrick.There are 38 figures,14 tables and 82 references.