Verification of Single Digit Emission Performance of a 24 MW Gas Turbine: SGT-600 3rd Generation DLE
The SGT-600 3rd generation DLE is a 24 MW industrial gas turbine which was recently upgraded from the SGT-600 2nd generation DLE. The upgraded SGT-600 is an addition to the existing low emissions gas turbine portfolio within Siemens. The objectives of the engine upgrade focused on increasing the lifetime of the components, lowering emissions and improving liquid fuel operation. In order to accomplish these objectives the combustion system was fully replaced, an improved gas fuel distribution was implemented and the first stage of the turbine was replaced. Furthermore, the liquid fuel injection system was enhanced in terms of fuel droplet distribution. Both gas and liquid fuel operation were confirmed in Siemens industrial gas turbine test facility located in Finspong, Sweden. The upgraded combustion system originates from the SGT-700 gas turbine, a 33MW class engine, which consists of 18 “3rd generation DLE” burners that replaced the original “2nd generation DLE” ones that are normally incorporated in the SGT-600 DLE gas turbines. The first stage of the turbine has also been improved and less air is needed for cooling purposes. Moreover, an additional update on the compressor air bleed control was implemented. The liquid fuel burner hardware was optimized with new fuel injection lances manufactured by electron erosion techniques in order to improve the droplet distribution. The SGT-600 3rd generation DLE is capable to operate in single digit conditions both in NOx and CO from 100% to 70% load and it is possible to extend single digit operation on NOx down to 50% load. CO emissions are below 80ppm at 50% load which is in compliance with current European regulation. Concerning liquid fuel operation the SGT-600 3rd generation DLE does not use water injection for emission control and is capable to reach below 58ppm NOx at full load while keeping CO below 40ppm down to 75% load. The present work describes the main modifications performed during the engine upgrade and the results of the performed engine tests. Finally, it should be noted that the SGT-600 3rd generation DLE is an excellent example of the development/upgrade efforts within Siemens AG. The commercialization process of the SGT-600 3rd generation DLE has been initiated and three engines are already in commercial operation up to date, and two units will be installed in the near future.