RESUMO
The development and performance of a perforated plate burner (PPB) operating using premixed natural gas and air at engine-relevant inlet temperatures and combustor pressures with thermal powers up to 1 MW is discussed. A significant benefit of using burners with simplified flow fields, such as the PPB, for experimental studies in the laboratory is the potential for decoupling the complex fluid dynamics in typical combustors from the chemical kinetics. The primary motivation for developing this burner was to use it as a source of vitiated flow with negligible swirl for reacting jet in vitiated crossflow experiments. The design methodology for the PPB is described, including plate geometry selection and flashback mitigation features. The stable operation of the PPB within a high-pressure test rig was validated: successful ignition, effective use of red-lines for flashback mitigation, and long duration steady-state operation in both piloted and nonpiloted modes were all observed. Exhaust gas emissions measured using a Fourier-transform infrared (FTIR) spectrometer showed very good performance of the PPB in terms of the combustion efficiency (based on measured CO and UHC), and a stability diagram of the PPB was developed as a function of the equivalence ratio and the PPB hole velocity. FTIR measurements also showed very low levels of NOX in nonpiloted operation that were generally within 3 ppm (reported dry and referenced to 15% O2). The capability for steady-state operation, high combustion efficiency, and low levels of NOX makes this PPB an excellent burner candidate for combustion experiments in the laboratory.
