大型船舶柴油机性能模拟及优化计算

在Matlab仿真环境下建立了某大型低速二冲程船用柴油机的零维模型,并利用柴油机推进特性的实验数据验证了模型的准确性.基于仿真模型,分析了不同压缩比和燃烧始点对柴油机标定工况下主要性能参数的影响.利用Isight-Matlab联合仿真优化平台,以柴油机油耗为优化目标,以最高爆发压力、最高爆发压力与压缩压力之差、最高燃烧温度和排气温度低于限制值为约束条件,对标定工况下柴油机的压缩比和燃烧始点进行联合寻优.仿真计算结果表明,标定工况下柴油机的经济性和动力性均有一定改善.

Performance Simulation and Optimization of a Large Marine Diesel Engine

A zero-dimensional model of a large-scale, low speed, two-stroke marine diesel engine was developed in a Matlab simulation environment. The model was validated by using the experimental data of propulsion characteristics. The effects of compression ratio and ignition point on engine performance parameters at rated operating point were analyzed based on the model. An optimization model was developed to optimize the engine performance under the rated operating condition. In the optimization model, the objective function was the specific fuel consumption, while the constraints were the peak pressure, and the difference between peak pressure and compression pressure, the maximum combustion temperature and exhaust temperature which were within the specified limits, and the design variables were the compression ratio and ignition point. Simulation results of obtained optimized scheme show that the engine performance in terms of fuel consumption and power at rated operating point are both improved.