Ten Years of DLE Industrial Gas Turbine Operating Experiences

Industrial gas turbine manufacturers began offering engines configured with dry low emissions (DLE) control in 1992. In the past ten years the performance and emissions reductions have been well demonstrated by DLE equipment. To date DLE gas turbines have relied on lean premixed combustion technology to achieve emissions reductions of 8 to 10 fold from “conventional” diffusion flame engines. The significant new content incorporated for DLE combustion systems has required industrial gas turbine manufacturers and users to work with greater synergy to overcome significant challenges. As evidence of this ultimately successful integration, DLE gas turbines are now as common in service as conventional diffusion flame engines. With thousands of DLE units sold one would expect that DLE gas turbines are now a mature product. In many aspects, this is true. However, emissions regulations and other market drivers have continued to change, forcing DLE equipment to continually evolve. A Solar history of DLE gas turbine developments, capabilities, and experiences are provided to give operators background and knowledge to reduce field issues and maximize availability of their DLE gas turbines. Design limitations and problems encountered in the field are discussed along with the steps that were taken to resolve them. Recommendations on DLE engine operation to avoid unscheduled downtime are presented. Design improvements to reduce emissions further and improve system flexibility are summarized.