Combustor development for automotive gas turbines

This paper describes the development of a combustion system for the AGT 100 automotive gas turbine engine. The AGT 100 is a 100 hp engine being developed by Detroit Diesel Allison Division of General Motors Corporation. To achieve optimum fuel economy, the AGT 100 engine operates on a regenerative cycle. A maximum turbine inlet temperature of 1288/sup 0/C (2350/sup 0/F) is reached, and air is supplied to the inlet of the combustor at temperatures as high as 1024/sup 0/C (1875/sup 0/F). To meet the low-emission and high-durability requirements at these conditions, a premix/prevaporization ceramic combustor employing variable geometry to control the temperature in the burning zone has been developed. A test section capable of handling 1024/sup 0/C (1875/sup 0/F) inlet air was designed and fabricated to evaluate this combustor. Testing of both metal (transpiration cooled) and ceramic combustors was conducted. Emissions were measured and found to be a function of burner inlet temperature. At 999/sup 0/C (1830/sup 0/F) burner inlet temperature, NO /SUB x/ emissions were two orders of magnitude below the program goals. At the same temperature but at a different variable-geometry position, the CO was 30 times below the program goal. Considerable testing was conducted to evaluate themore » behavior of the ceramic materials used in the combustor. No failures occurred during steady-state operation; however, some cracks developed in the dome during extended transient operation.« less