基于随机规划的不确定蒸汽动力系统优化设计

发布时间：2018-03-02 20:30

本文选题：蒸汽动力系统　切入点：随机规划　出处：《大连理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：目前我国的能源和环境问题日益严峻,石化企业的节能减排势在必行。其中蒸汽动力系统是过程工业的重要组成部分,它消耗大量的一次能源为过程系统提供蒸汽、电力等。在实际蒸汽动力系统优化设计中不可避免包含蒸汽电力需求变化、能源价格波动等不确定因素。不确定因素会使系统操作偏离最优设计状态,造成设计策略保守或过程不合理,甚至带来安全隐患,所以在蒸汽动力系统设计中进行不确定优化研究具有重要的理论和实际意义。因此,本论文提出应用随机规划策略对不确定蒸汽动力系统设计优化进行研究。首先分析了蒸汽动力系统设计包含的不确定因素的特性及其对系统优化目标和约束条件的影响。将不确定因素的表达分成两类：基于时间变化表达和基于发生概率表达。对基于时间变化表达的因素,转化为多周期问题进行处理；对外部工艺过程变化引起的汽电需求不确定波动等基于发生概率表达的因素,应用随机规划策略补偿不确定参数的实现可能引起的约束背离。建立多周期带补偿的随机规划MILP模型对蒸汽动力系统进行设计优化。然后,在此基础上,同时考虑蒸汽过热度来优化蒸汽参数的选择、设备选择和各设备的操作负荷。并通过案例来分析过热度对蒸汽动力系统结构配置和性能的影响。此外,将污染物排放纳入蒸汽动力系统的设计优化中,从而在系统设计中选择最优燃料,实现经济成本和环境影响的最佳权衡。案例研究表明：本文提出的多周期带补偿的随机规划(MP-SPR)方法是一种确定设备尺寸、操作负荷和系统运行工况的有效工具。对不确定因素采取随机规划策略,通过调节决策和惩罚不足协调运行的补偿方式来指导操作,使调度调节更加合理,实现了结构和操作的同时优化,将年操作费用降低了9.51%,年投资费用降低了4.57%。与传统确定性方法相比,MP-SPR方法不仅能应对各种汽电需求的不确定变化,同时保证了系统的安全稳定运行和经济效益最优,提出的设计方案使年总费用降低了8.72%。蒸汽过热度会影响蒸汽动力系统的性能,如蒸汽分配以及产电量等。在系统设计中,它还会影响设备选择以及各设备尺寸等。在适当的过热度范围内,当改变高压蒸汽过热度时,随着过热度的增大,呈现投资费先减小后增加,总费用先减小后增加的趋势。本研究考虑各种不确定因素以及环境因素的影响,能为我国的节能减排事业做出巨大贡献,具有重要的理论和实际意义。
[Abstract]:At present, the energy and environment problems in our country are becoming more and more serious, so it is imperative for petrochemical enterprises to save energy and reduce emissions. Among them, steam power system is an important part of the process industry, and it consumes a lot of primary energy to provide steam for the process system. In the optimization design of actual steam power system, the change of steam power demand, the fluctuation of energy price and other uncertain factors are inevitable. The uncertain factors will make the system operation deviate from the optimal design state. The design strategy is conservative, the process is unreasonable, and even the hidden trouble of safety is brought, so it is of great theoretical and practical significance to study the uncertain optimization in steam power system design. In this paper, stochastic programming strategy is used to study the design optimization of uncertain steam power system. Firstly, the characteristics of uncertain factors in steam power system design and its optimization objectives and constraints are analyzed. The expression of uncertain factors is divided into two categories: expression based on time change and expression based on probability of occurrence. To deal with the multi-period problem, and to deal with the uncertain fluctuation of the demand for steam and electricity caused by the change of the external process process, and so on, based on the factors of probability expression, The stochastic programming strategy is applied to compensate for the constraint deviation caused by the realization of uncertain parameters. A stochastic programming MILP model with compensation is established to optimize the design of steam power system. At the same time, the selection of steam parameters, the selection of equipment and the operating load of each equipment are considered. The influence of superheat on the configuration and performance of steam power system is analyzed by a case study. The pollutant emission is incorporated into the design optimization of the steam power system, and the optimal fuel is selected in the system design. The optimal trade-off between economic cost and environmental impact is achieved. The case study shows that the multi-period stochastic programming with compensation proposed in this paper is a method to determine the size of equipment. An effective tool for operating load and system operating conditions. Random programming strategy is adopted to deal with uncertain factors. The operation is guided by adjusting decision making and compensating for inadequate coordinated operation to make scheduling and regulation more reasonable. The structure and operation are optimized at the same time, the annual operating cost is reduced by 9.51and the annual investment cost is reduced by 4.57.Compared with the traditional deterministic method, the MP-SPR method can not only deal with the uncertain changes of various steam and electricity demand. At the same time, the safe and stable operation of the system and the optimum economic benefit are ensured. The design scheme proposed in this paper reduces the total annual cost by 8.72%. The steam superheat will affect the performance of the steam power system, such as steam distribution and electricity production. It will also affect the selection of equipment and the size of each equipment. In the appropriate superheat range, when the superheating degree of high-pressure steam is changed, with the increase of superheat, the investment cost decreases first and then increases. Considering the influence of various uncertain factors and environmental factors, this study can make a great contribution to the cause of energy saving and emission reduction in China, which has important theoretical and practical significance.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ083

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