| After years of R&D about coal gasification technology,the native pulverized coal gasification technology has made considerable progress and achieved some leading qualities.Though the entrained-flow pulverized coal gasification technology has the advantages of high gas production and high efficiency,there are still some problems in the actual gasifier operation,that restrict the stable operation of the gasifier and affect the economic benefits of the subsequent coal chemical process.In this paper,several problems about the GSP gasifier in a coal chemical park was considered,such as the easy breakable slag tap and the burning through of the downcomer during the operation.Firstly,computational fluid dynamics(CFD)method was used to study the combined structure of the original pagoda-shaped slag tap and downcomer.The temperature,pressure and streamline distribution of the slag tap and downcomer were obtained.Then,the reasons for the failure of the pagoda-type slag tap were analyzed;a better stepped slag tap structure was proposed,and technical transformation was implemented furthermore.Combined with the operation data,the improvement of slag tap structure was analyzed.The results show that the structure of slag tap has a significant effect on the gas phase temperature and streamline distribution inside the downcomer.The radial temperature gradient of the downcomer is significantly different,the rigidity of the pagoda-type slag tap jet is poor,and the chilled water has a greater impact on the jet.The structure of the improved stepped slag tap has the advantages of good airflow rigidity and stable streamline,which is beneficial to the long-period operation of the gasifier.After the improvement of the slag tap,the frequency of maintenance was reduced from 5 times to 2 times a month,the synthesis gas composition deviation was controlled within 5%,the average heat loss difference was within 0.1%.The residual carbon content in the gasifier slag was reduced by 0.13%,and the overall process parameters remained stable.The on-site operating data shows that the operating data has been significantly improved,and the related results can also provide a reference for the process design of the quench chamber of this gasifier. |
