A High-Temperature Catalytic Combustor With Starting Burner

Abstract

A catalytic combustion system has high potential to achieve low NOx emission level. When this combustion system is applied to a gas turbine, the required combustor performance must be maintained over a wide range of operating conditions. These conditions range from cold starting to steady-state operation. Particularly during the initial stage of cold starting when the catalyst is not yet activated, the catalyst must be heated by some means. This study proposes a new concept of a catalytic combustor with a direct heating system using vaporizing tube for starting burner in order to downsize the combustor and reduce the warm-up time during cold starts. The effectiveness of this concept is experimentally verified. Furthermore, NOx, CO, and HC emissions during startup can be reduced to a low level so as to achieve ultra-low pollution of the catalytic combustion over a wide range of operating conditions from cold start to steady-state operation. This paper outlines the operation concept covering cold start, verification of the concept through the experiments with flame visualization in the combustor, spray characteristics, construction of the combustor, and combustion characteristics that show low pollution in various operating conditions of the catalytic combustor.

Numerical and experimental investigation on the performance of lean burn catalytic combustion for gas turbine application

“…A method for enabling cold starting of lean burn catalytic combustion gas turbine systems, such as installing a preburner in front of the catalytic combustor and initially employing a starting burner then using a bypass valve to switch after the combustion warms up, has been developed [17]. It is an effective means for combustion lightoff if compressor or recuperator discharge temperatures are too low.…”