A COMBUSTION TEST FACILITY FOR TESTING LOW NO_X COMBUSTION SYSTEMS

摘要

Cheng Power Systems has designed and built an atmospheric pressure combustion test facility for gas turbines, which has the capability of testing the full size combustion systems of large gas turbines at atmospheric pressure while maintaining the adiabatic flame temperature at pressurized conditions. The uniqueness of the test facility is the method of preheating the air to the compressor discharge temperature of a gas turbine at high-pressure ratios using the combustion exhaust gas and a compact air-to-air heat exchanger. The exhaust dampers and dilution airflows control the preheated-air temperature. The other characteristic of the test facility is the competence of testing NO_X reduction combustion systems using steam or inert gas. The facility has the capability to perform steam injection experiments to examine the combustion stability with massive steam injection rates of up to 20% of air mass flow rate. The test process is fully automated with computer data acquisition and digital control. Combustion systems such as GE Frame 5P, 6B, 7EA, and Westinghouse 501D5 A have been tested. With Cheng Power's unique NO_X reduction system (CLN~(TM)- Cheng Low NO_X System), less than 5 ppm NO_X and very low level of CO were obtained for these combustion systems without hardware modification. The facility is also capable of testing Dry-Low-NO_X (DLN) combustion systems. The test system is also assisted by a commercial computer program (Star-CD) to estimate the pressurization effect for extrapolating the test results. The pressure dependence can be simulated with the unique combustion geometry, type of fuel, and onset of turbine inlet temperature, respectively. The results depict the detail of the flame structure under various combustion chamber design characteristics. The model pressurization results correlate well with our experimental results as well as results in the literature.