Numerical and experimental investigation on emission performance of a fuel staged combustor

The low NOx emission technology has become an important feature of advanced aviation engine. A wide range of applications attempt to take advantage of the fact that staged combustion under lean-premixed-prevaporized (LPP) conditions can significantly cut down emission and improve combustion efficiency. This paper proposes a scheme with fuel centrally staged and multi-point injection. The mixing of fuel and air is improved, and the flame temperature is relative low in combustion zone, minimizing the formation of nitrogen oxides (NOx), especially thermal NOx. In terms of the field distribution of equivalence ratio and temperature obtained from Computational Fluid Dynamics (CFD), a chemical reactor network (CRN), including several different ideal reactor, namely perfectly stirred reactor (PSR) and plug flow reactor (PFR), is constructed to simulate the combustion process and predict pollution emission. The influences of the pilot equivalence ratio and percentage of pilot/main fuel on NOx and carbon monoxide (CO) emission were investigated by CRN model. The effects of the pilot fuel and primary fuel on pollution emission were investigated experimentally. Finally, the effects of pilot equivalence ratio and pilot fuel proportion on NOx emission were discussed in detail by comparing predict of CRN and experimental results.