Development of Gas Turbine Combustion Tuning Technology Using Six Sigma Tools

A conventional combustion tuning method for a gas turbine needs more than 24 hours with lots of human labor. In addition it is hard to certify whether the plant is optimized because the conventional tuning is based on human decisions and subjective empirical data over a long time. In this study we developed a combustion tuning technology using six sigma tools (CTSS) to effectively meet the increasingly stringent NO_x regulations and to save combustion tuning time. CTSS was conducted in five steps—define-identify-design-optimize-verify (DIDOV). First, the NO_x reduction target was defined (Step 1, define), the current status of the plant was diagnosed (Step 2, identify), and the vital few control parameters to achieve the defined target were determined by analyzing the correlation between the control parameters and NO_x emissions (Step 3, design). For the next step, the optimum condition was derived from one of the six sigma tools (Step 4, optimize), and finally the optimum condition was verified by applying the condition to the gas turbine combustion (Step 5, verify). As a result of CTSS, averaged NO_x emissions were reduced by more than 70% and the standard deviation was improved by more than 60%. These results show that CTSS is a potential tool for enhanced reliability of plant operations and scientific method for quick and exact combustion tuning.