Quality Control And Improvement Of Integrated Coal Gasification Combined Cycle Gasifier Of S Company

Integrated gasification combined cycle(IGCC) is an advanced power system, it will gradually replace the existing steam turbine power station, become the main development direction of thermal power generation. The gasifier is the core equipment of the system, and S company faces the problem of welding quality and dimension deviation in gasifier manufacturing, has not been improved obviously.This article is take the Tianjin Green Gen project 250 MW IGCC of S company as the practice object, from the view of the theory and the practice of engineering application, research on IGCC gasifier quality control and improvement.This article analyses the quality control of gasifier, using fishbone diagram analysis of critical quality control process, using the pareto diagram and histogram analysis that the offset out of tolerance, welding crack, ellipticity out of tolerance, welding deformation is the main quality defects of gasifier. Put forward that it's should use PFME this preventive technology, analyse the potential failure modes and causes and the preventive measures should be put forward before manufacture, in order to reduce the cost of quality.This article makes the quality control process analysis and improvement of IGCC gasifier based on the PFMEA method. Use the PFMEA method separately make the potential failure modes and causes analysis on the three aspects of shell welding, rolling cylinder, cylinder assembly, according to the severity(S), likelihood of detection(D), frequency of occurrence(O) criteria for calculating the risk priority number(RPN), use of error proofing technology on higher RPN potential failure mode and put forward the specific error proofing measures, effectively reduce the RPN value and feedback to PFMEA. The main measures are: the establishment of automatic welding real-time monitoring system, and strictly take the examination and rewards accordance with the system; using optical measuring instrument for monitoring the welding deformation and guidancing the assembly of 45 °cylinder, and make a technical summary; perfect nondestructive defect location scheme; improve the process and tooling, and forming process modification paper; strictly implementation the <key control point circulation card>; according to the technical requirements, difficulties and the correspongding technology make a summary and forming the< IGCC gasifier process scheme >.This article make a statistic of the quality test result of the product after it completed, the welding quality and dimention deviation reached to requirements of standard.By compared the implementation result of the quality goal before and after improvement, the qualified rate of welding seam, qualified rate of butt welding, pressure test first-time pass rate, customer complaints quantity, unit capacity waste situation is remarkably improved, verified the effectiveness of the prophase quality control method and measure.This article throughs by the study of the IGCC gasifier quality control and improvement, not only improved the quality of IGCC gasifier, also established a set of quality control methods to suit the gasifier product for the company, it worth to refereced and popularized to similar products.