【作者】 甘辉兵；

【导师】 任光；

【作者基本信息】 大连海事大学 ， 轮机工程， 2012， 博士

【摘要】 随着我国LNG船队的不断发展与壮大,通过轮机模拟器对LNG船舶轮机管理人员进行相应的教育与技术培训对培养技能娴熟的轮机管理人员有着重要意义。我国现阶段完全依赖国外昂贵的LNG船轮机模拟器产品进行教育与培训,定程度上制约了我国LNG船舶运输业的发展。为了打破国外昂贵产品的垄断、节约资金,非常有必要对典型LNG船推进系统进行系统的数学建模与仿真研究,为研制具有自主知识产权的LNG船轮机模拟器奠定理论与实践基础。以国产LNG船的推进系统为研究对象,采用模块化与集总参数建模方法分别建立了LNG船主推进系统中双燃料主锅炉本体模型、典型的主锅炉辅助系统模型、主推进汽轮机系统模型及简化的螺旋桨推进模型。以Matlab/Simulink为仿真工具,进行了仿真计算分析,仿真结果与设计试验数据和部分试航数据作了对比分析；从宏观整体描述的角度,采用系统动力学理论建立了推进系统中典型的动态特性分析模型,并采用VENSIM仿真工具进行仿真,将仿真结果与经典微分方程模型仿真结果进行了比较分析；在已验证的模型基础上,开发了LNG船轮机模拟器中的推进仿真系统。具体而言本文的主要贡献包括以下几部分：针对国产LNG船中双燃料主锅炉系统的特点,合理详细的划分了锅炉本体部分子模块,分别建立了各个子模块的数学模型,包括炉膛、汽包、水冷壁上升管、下降管、水筒与联箱、过热器、经济器、空气预热器及烟气侧传热模型。在炉膛动态模型中,首次结合双燃料燃烧的特点,引入燃油与燃气份数,建立炉膛烟气含氧量仿真模型,可以扩充炉膛监控参数仿真范围；给出了一种简化的内嵌式过热器仿真计算模型,可以兼顾轮机模拟器仿真精度与仿真速度的要求；在Matlab/Simulink中将各个子模块模型连接成整体锅炉模型进行仿真分析,分别进行了静态和动态仿真试验,其中静态仿真数据与实际数据吻合良好,整体精度在5%以内,满足轮机模拟器的稳态精度要求：动态仿真趋势合理,符合实船动态响应规律。还分析和建立了主锅炉燃油系统、天然气系统及除氧给水系统模型,改进了燃油系统模型中舱柜液位计算模型。针对国产LNG船中主推进汽轮机及其推进轴系的特点,建立了汽轮机本体数学模型、推进轴系模型、船—桨模型,并连接构成整体模型,应用Matlab/Simulink搭建了相应的仿真模型,并进行了系统仿真试验,仿真结果表明,稳态仿真结果与设计数据吻合良好,满足轮机模拟器的整体精度要求；动态仿真趋势合理,与试航工况数据趋势一致。以系统动力学理论为基础,从宏观系统分析的角度出发,建立了LNG船汽轮机系统动态特性分析模型。在VENSIM平台下,分别建立了其因果回路、流量存量图及结构方程,并进行了仿真研究。结果表明,该方法建立的模型的精度与动态特性和经典模型相当,且更加直观体现了系统的本质,描述确切、繁简适当,适用于LNG船汽轮机系统的动态特性分析与优化控制,并可推广到整个轮机系统的整体优化建模与分析。最后,以建立和验证的数学模型为基础,通过高级语言编程实现,开发出了国内首套LNG船推进仿真系统,该部分是LNG船轮机模拟器的核心内容。对LNG船轮机模拟器进行了整体规划和设计,并从仿真模型程序与仿真界面设计的角度出发,提出了切实可行的优化设计方法；采用Visual C#开发工具编程实现了推进仿真系统软件,包括主锅炉系统、主推进汽轮系统、推进系统监测与报警及教练员管理系统等软件模块。开发的软件系统具有界面美观大方、操作方便灵活、实时性强、模型精度高及专业性强等优点。该系统的成功开发对推动我国LNG船舶轮机管理人员的教育与培训有着重要意义。更多还原

【Abstract】 With the development and growth of China’s LNG fleet, it is significant to train skilled marine engineers for LNG carrier through the marine engine room simulator. However, it is entirely dependent on foreign expensive engine simulators of LNG carrier for marine engineers’ education and training at present stage in China. The situation has restricted the development of China’s LNG carrier transportation to a certain extent. Therefore, in order to break the monopoly of foreign expensive products and save money, it is necessary to carry out mathematical modeling and simulation research for a typical LNG carriers’propulsion system, which lays the foundation of theory and practice for the developing of the LNG carrier engine simulator, which has independent intellectual property rights.In this thesis, the propulsion system of domestic LNG carrier is taken into study. Using the methods of modular modeling and lumped parameters modeling to establish the dual-fuel main boilers model, typical auxiliary systems model of main boilers, main propulsion steam turbine system model and simplified propeller model. The Matlab/Simulink software is the simulation tool. Simulation results are compared with designed experimental data and some sea-trials data; using the system dynamics theory to establish the dynamic characteristics analysis model of LNG propulsion system from the macro description perspective. The VENSIM software is the simulation tool. Simulation results are compared with the classical differential equation model simulation results; the main propulsion simulation system for LNG carrier is developed on the basis of verified model. Specifically, the main contribution of this thesis includes the following:According to the characteristics of the dual fuel main boiler system for domestic LNG carrier. reasonable boiler sub-modules are divided in detail. Mathematical model for each sub-module is established, including the furnace, drum. rising water wall tube, downcomer, water tube and header, superheater, economizer, air preheater and flue gas side heat transfer model. In the furnace dynamic model, the ratio of fuel oil and fuel gas is defined to establish the furnace flue gas oxygen content simulation model, which expands the simulation parameters. A simplified internal embedded superheater simulation model is given. which meets the requirements of accuracy and simulation speed in simulator. The whole boiler simulation model in Matlab/Simulink is established through linking sub-models and carrying out static and dynamic simulation. The static simulation data agrees well with the actual designed data, and the overall accuracy is less than5%, which can meet the requirements of steady-state accuracy of engine room simulator; dynamic simulation data" trend is reasonable, which is consistent with the dynamic corresponding characteristic of the real ship. Also the main boiler fuel oil system model, fuel gas system model and feed-water system model are analyzed and established through analyzing. An improved simulation model for fuel oil tank level computational is conducted.According to the characteristics of main steam turbine system and propulsion shaft system for domestic LNG carrier, the main steam turbine mathematical model, propulsion shaft model, simplified propeller and ship motion model are established. The whole simulation model in Matlab/Simulink is established through linking sub-models and carrying out static and dynamic simulation. Simulation results show that the steady-state simulation results are consistent with design data, which meet the requirements of the whole accuracy of the simulator; dynamic simulation results basically correspond to the sea-trial data.From a macro point of view of systems analysis, a dynamic characteristics analysis model of LNG carrier propulsion system is established based on system dynamics theory. In VENSIM platform, the causal loop diagram, stock and flow diagram, structure equations are established, and simulation studies are conducted. The simulation results show that the system dynamics model is easy to understand presentation, simplified and high accuracy, which is appropriate for the dynamic characteristics analysis and optimized control of LNG carrier steam turbine system. This modeling method can be extended to the optimization modeling and analysis of the whole marine system.Finally, on the foundation of established and validated models, the first set of domestic LNG carrier propulsion simulation system is developed through high-level computer programming language. This simulation system is the core of the LNG carrier engine room simulator. The overall planning and design of the LNG carrier engine room simulator is conducted, and a practical optimization method is put forward from the perspective of the simulation model and simulation program interface design. Using the Visual C#programming language, the simulation software is developed successfully. including the main boiler system, main steam turbine propulsion system, monitoring and alarm system, and coach management system software module. The developed software system has advantages such as nice interface, easy and flexible operation, real-time, high accuracy and profession. The successful development of the system will promote China’s LNG carrier engineers’education and training.更多还原