In situ combustion coating of gas turbine components during the operation of a heavy-duty land-based gas turbine

摘要

Gas turbine is an internal combustion engine used for expelling aircrafts or for driving a generator to produce electricity. The higher thermal efficiency of the engine is obtained at higher combustion temperatures, for which some hot-section metallic components are thermally protected from hot combustion gas. A technology for “in situ” building up protective oxide layers was applied to a heavy-duty gas turbine power generation system commercially in service, and its effects on the operation of the gas turbine were tested. An organic mixture designed to produce metallic oxides was sprayed into the combustion chamber for an hour during the natural gas operation. White deposits were observed to have covered all the surfaces of the hot-section components including the turbine blades. The operation data showed an increase in the efficiency of the gas turbine by 0.36%P, and a decrease in the exhaust gas temperature by ~7.8°C. Reasons for these results were considered to be the improved thermal insulation and reduced hot gas leakage due to the in situ deposited materials.