船用低速柴油机燃用重油的酸露点温度分析

以某型低速柴油机为研究对象,采用性能仿真软件搭建发动机模型,得到缸内温度、压力及成分变化规律;结合SO_3生成反应化学动力学模型,计算分析燃气酸露点温度随曲轴转角的变化规律。结果表明:随着活塞的下行,酸露点温度下降;且缸内温度下降的速度大于酸露点温度的降幅,因此在低负荷时下止点附近容易出现酸低温腐蚀现象。指出冷却系统设计时要充分考虑这个因素。

Analysis of the Acid Dew-Point of a Low-Speed Marine Engine Using Heavy Fuel Oil

Taking a certain kind of low-speed diesel engine as an example, the distributions and variations of the temperature, pressure and composition inside the cylinders were output by a simulation software. By introducing the chemical kinetic model of the SO₃ formation, the change rule of the acid dew-point with the crank angle was calculated. The results show that the acid dew-point temperature decreases as the piston go down; the in-cylinder temperature decreases more rapidly than that of the acid dew-point, therefore, the acid low temperature corrosion is more likely to occur around the BDC, and should be taken into consideration the design of the cooling system.