| 论文简介 |
Ammonia (NH3) combustion is regarded as one of the most promising solutions to realize zero CO2 emis-sion. However, its low reactivity, low heat release result in a strong thermal effect (wall heat loss effect) which significantly affects flame macro structure and NOx emission characteristics. In this study, an air film cooling on the swirling combustion chamber was designed to investigate the wall heat loss effect on NOx emission. The flame structure and NO production were measured with the OH-/NO-PLIF techniques. The NOx emission was analyzed by the Gasmet DX40 0 0 Fourier Transform Infrared (FTIR) gas analyzer. Large eddy simulation was also conducted with detailed chemistry to extend the understanding of the experimental findings. For the current combustion chamber, a larger convection heat loss was obtained when increasing the cooling air flow rate. NO emission shows a decreasing trend with heat loss which is mainly caused by the chemical reactions at near all region. This can be verified by the relatively far-ther NO profile from the combustor wall. By analyzing the LES results at near all region, the combustion efficiency is decreased due the lower temperature. As a result, NO production from HNO and NH path-way is suppressed due to the local OH decreasing in near-wall region. The larger unburned NH3 in the exhausted gas may also consumes NO by the NO reduction reactions. In comparison, N2O, around 300 times global warming potential than that of CO2, significantly increases as the heat loss increases. This is mainly because that the production of N2O from NO is promoted and N2O decomposition is suppressed within the thermal boundary. This study suggests that N2O might become a more serious emission com-ponent in NH3 fueled gas turbines. Furthermore, the heat loss effect on the NOx production should be fully considered when designing the gas turbine combustion chamber with strong wall cooling.& COPY; 2023 The Combustion Institute. Published by Elsevier Inc. All rights reserved. |
(创新港)
