【作者】 李萍；

【导师】 汪军；

【作者基本信息】 东南大学 ， 动力机械及工程， 2018， 硕士

【摘要】 大型凝汽式汽轮机系统设备建模与运行初压优化的研究对于掌握汽轮机系统运行特性、提高机组热经济性有着十分重要的意义。本文以某660MW超临界机组汽轮机系统为研究对象,建立了系统各设备的机理特性模型,并考虑机理模型与实际运行工况之间的偏差,建立了结合机理和数据的汽轮机系统混合模型,在此基础上开展了汽轮机运行初压优化工作。主要研究内容包括:首先,基于各设备的机理建立了汽轮机本体、冷端系统、回热系统及给水系统的特性模型,并根据各系统参数之间的关系将模型联结,形成汽轮机系统特性模型,为后续章节模型的修正和运行初压优化提供模型支持。其次,根据机组实际运行数据,采用最小二乘支持向量机算法建立数据驱动模型,并与机理模型结合,得到汽轮机系统混合模型。混合模型与机组的实际运行状态接近,具有较高的精度,保证了初压优化的可靠性。再者,建立了综合考虑汽机热耗率及凝结水泵与循环水泵耗功的机组初压优化模型,并在最优初压可行区间内寻优,得到了给定负荷及天气条件下的机组的最优运行初压及对应最佳循环水泵运行方式与配汽机构阀门开度。最后,根据本文所建模型和最终优化结果,开发了基于Visual Studio.Net和PI数据库的汽轮机系统性能监测平台及运行初压优化软件指导系统。更多还原

【Abstract】 The research on equipment modeling and operating initial steam pressure optimization of large condensing steam turbine system plays a crucial role in mastering the operating characteristics of steam turbine system and improving the thermal economy of the units.Therefore,taking the steam turbine system of a 660 MW supercritical unit as the object,this paper established the characteristics model of each equipment based on the mechanism and the hybrid model of steam turbine system combining the mechanism and data in considering the deviation between the mechanism model and the actual measurements.The optimization of operating initial steam pressure was carried out based on the hybrid model.The main research contents were as follows.First of all,the steam turbine system model based on the mechanism was established by connecting the characteristics models of the turbing iroper,the cold-end system,the regenerative system and the water supply system through the relationship between the parameters of each system,which is the foundation of model modification and operating initial steam pressure optimization in post chapters.Secondly,a hybrid model of steam turbine system was established by connecting the mechanism model and the data-driving model which was established by the least squares support vector machine based on the actual operation data.The hybrid model is close to the actual operation state of the unit and has high precision,which guarantees the reliability of the initial pressure optimization.Furthermore,an optimization model was established considering the heat consumption rate of steam turbine as well as the energy consumption of condensate water pump and circulating water pump.Based on the model,the optimal operating initial steam pressure was given as well as the corresponding optimal circulating water pump operation mode and valve opening of steam distribution mechanism when the weather condition and unit load were known.Finally,according to the models the paper established and the final optimization results,the platform of steam turbine system performance monitoring and optimization of operating initial steam pressure was developed based on Visual Studio.Net and PI database.更多还原