基于AVL BOOST的船舶柴油机SCR催化剂储氨特性仿真

为研究SCR催化剂的储氨特性，基于AVL BOOST软件建立某型船舶柴油机SCR催化剂模型，仿真研究不同温度和空速下的SCR催化剂储氨动态过程与储氨量，以及储氨量对转化效率的影响.结果表明：相同空速下，温度增大后催化剂储氨能力显著降低，氨存储时间以及饱和储氨量随温度升高呈线性减小的趋势；相同温度下，空速增大后加快了NH3泄漏，从而使氨存储时间和饱和储氨量有不同程度的降低.低温时（280℃以下），空速对饱和储氨量的影响较大，随着空速增大，饱和储氨量逐渐减小；较高温度时（280℃以上），空速对饱和储氨量的影响非常小.低温时，转化效率随储氨量增大而提高，随着温度的升高，储氨量对转化效率的影响逐渐减小.
To study the ammonia storage characteristics of SCR catalyst, SCR catalyst model for marine diesel engine was established based on AVL BOOST to study SCR catalyst ammonia storage dynamic process, ammonia storage amount and its effect on conversion efficiency in different temperatures and space velocities. Simulation results show that under the same space velocity, the ammonia storage capacity of the catalyst decreases with the increase of temperature, which results in the decreasing of the ammonia storage time and ammonia storage amount. Under the same catalyst temperature, the increase of space velocity causes earlier appearance of ammonia slip, as consequence, the ammonia storage time and ammonia storage amount decrease. The effect of space velocity on the ammonia storage amount tends to be obvious with the lower the catalyst temperature(under 280℃), but under higher temperature(up 280℃), the effect of space velocity on ammonia storage amount tends to be less. At low temperature, the conversion efficiency increases as the ammonia storage amount rising, and the effect of ammonia storage amount on the conversion efficiency decreases with temperature increasing.