Siemens reports that it has successfully additively manufactured and engine tested a dry low emission (DLE) pre-mixer for the SGT-A05 aeroderivative gas turbine, with the test results said to show the potential for significant reductions in CO emissions. From concept to engine test, the company stated that the part’s development took only seven months, despite requiring very tight tolerances, load resistance and temperature resistance.
To produce the highly complex component using conventional manufacturing methods, over twenty parts would be involved in the casting and assembly process. Siemens stated that, using qualified nickel superalloys and metal Additive Manufacturing, the component design was consolidated into just two parts, representing a reduction in lead time of approximately 70%. Siemens was able to simplify production process complexity, reduce external dependencies in the supply chain, and improve the geometry of the component overall to allow a better fuel-air mix.
Vladimir Navrotsky, Chief Technology Officer for Siemens Power Generation Services, Distributed Generation, stated, “This is another excellent example of how Additive Manufacturing is revolutionising our industry, delivering measurable benefits and real value to our customers, particularly as they look to further reduce emissions to meet environmental targets. Our achievements using AM are paving the way for greater agility in the design, manufacturing and maintenance of power generation components.”
In engine testing, Siemens reported that the component showed no start issues, all fuel transitions were accomplished successfully without any controls modifications required, and there were no combustion dynamics or noise. Measurable CO emissions reductions were realised and full power was achieved.
The DLE solution for the SGT-A05 gas turbine reduces emissions using advanced lean burn combustion technology, eliminating the need for water injection. More than 120 engines using DLE technology are currently said to be in operation, with 3.9 million operating hours accumulated as of February 2018. Speaking on the first successful engine tests on the AM DLE pre-mixer, Douglas Willham, Siemens Director of Engineering for the SGT-A05, commented, ”Now, with AM technology we have an opportunity to go even further with emissions reduction for DLE combustion.”
In February 2017, Siemens finished its first full-load engine tests for gas turbine blades completely designed and produced using AM technology. In April 2018, it additively manufactured and installed into a customer’s equipment its first metal AM replacement part for an industrial steam turbine. The company states that it has accumulated more than 30,000 hours of successful commercial operation for SGT-800 burners repaired with AM technology, and for SGT-750 burner swirls manufactured by AM.