蒸汽动力舰船回汽制动机理与系统建模仿真

针对大型蒸汽动力舰船传统制动方法机动性差的问题,分析回汽制动技术的机理,并基于Matlab-Simulink环境,建立由调节阀、正车汽轮机、倒车汽轮机、螺旋桨及舰船负载等组成的回汽制动系统各组成部分及全系统的仿真模型。通过舰船的自然滑行试验和回汽制动试验,对模型进行验证。实验结果表明:仿真结果与试验结果基本一致,在汽轮机强度允许的范围内,回汽制动较传统制动方法能大幅度缩短制动时间,增加舰船机动性。

船舶回汽制动对主蒸汽系统运行特性的影响

基于实际船舶蒸汽动力系统运行机制,解析船舶回汽制动过程,利用CFD方法计算正车工况下主蒸汽系统管路速度场和压力场的稳态分布规律;拟合并引入基于二次程序开发的正倒车回汽流量模型作为动态计算边界条件,动态计算分析回汽制动过程蒸汽流量变化对主蒸汽系统的影响。结果表明,在回汽制动过程中,蒸汽分配箱、正车供汽管及倒车供汽管的最大压降满足主汽轮机操作规范要求。

Dynamic simulation of drum level sloshing of heat recovery steam generator

Drum level sloshing is the latest discovery in the application of heat recovery steam generator (HRSG) in combined cycle, and shows certain negative influence on drum level controlling. In order to improve drum level controlling, influence factors on the drum level sloshing were investigated. Firstly, drum sub-modules were developed using the method of modularization modeling, and then the model of drum level sloshing was set up as well. Experiments were carried out on the experimental rig, and the model was validated using the obtained experimental results. Dynamic simulation was made based on the model to get a 3-D graph of drum level sloshing, which shows a vivid procedure of drum level sloshing. The effect of feed-water flow rate, main-steam flow rate and heating quantity on the drum level sloshing was analyzed. The simulation results indicate that the signals with frequency higher than 0.05 Hz are that of drum level sloshing, the signals with frequency of 0.0-0.05 Hz are that of drum level trendy and "false water level", and variation of the feed-water flow rates, main-steam flow rates and heating quantities can change the frequency of drum level sloshing, i.e., the frequency of sloshing increases with the increase of feed-water flow rate, or the decrease of the main-steam flow rate and the heating quantity. This research work is fundamental to improve signal-to-noise ratio of drum level signal and precise controlling of drum level.