【作者】 戴文智；

【导师】 尹洪超；

【作者基本信息】 大连理工大学 ， 动力机械与工程， 2010， 博士

【摘要】 蒸汽动力系统是石化企业的重要组成部分,同时消耗大量燃料而产生大量污染物,造成了严重的环境问题。因此,蒸汽动力系统的优化操作,不仅是石化企业节能降耗、提高效益的重要途径,也对环境保护和人类社会的可持续发展有着重要的意义。依据蒸汽动力系统自身复杂运行特性对其进行深入理解和分析,是制定系统合理的运行优化方案的前提,对实现石化企业能量系统总体优化也至关重要。本文在阅读大量国内外与蒸汽动力系统多层次集成建模体系结构相关文献基础上,建立了蒸汽动力系统物理结构、流结构、功能层次模型和蒸汽动力系统多周期运行优化的数学模型。并基于粒子群算法收敛速度慢、全局寻优能力弱的缺点,提出了一种新的优化算法——线性变化参数的粒子群(ICPPSO)算法,对约束的处理进行了简化,把约束问题转化为无约束优化问题。运用ICPPSO算法对部分文献中的算例和实际算例进行优化求解,与其他方法相比能很快得到运行优化方案,降低了大量运行成本,表明了其实用性和有效性。石化企业中,由于生产量和季节变化等原因,造成了各周期间蒸汽和电的需求变化比较大,导致锅炉和汽轮机的频繁启停,不仅增加了运行费用,而且对设备的寿命影响较大。在对以往研究设备启停费用模型基础上本文提出了修正,如果不考虑设备启停时间,进行了数学意义上的修正；如果考虑设备启停时间对其模型提出两种修正方案,种方案是把蒸汽和电力需求约束分成三个时间段：设备启动、设备正常运行和设备停运时间；另一种方案是对设备启停逻辑约束进行修正,把启动周期提前、停运周期推迟。本文结合某石化企业的蒸汽动力系统实际情况建立了设备启停费用数学模型,运用ICPPSO算法采用分步求解策略得到了合理的优化运行方案,两种优化方案总运行费用分别减少1.4%和2.3%。该修正模型不仅具有数学方面的意义,而且对具有转运关系的调度问题也有参考作用。我国能源状况面临着经济增长和环境保护的双重制约,能源短缺和环境污染的压力会急剧加大。对此本文提出了包括环境成本在内的石化企业蒸汽动力系统多周期运行优化模型,该模型不仅考虑了污染物的排放,也考虑了污染物的减排因素,增加了污染物排放限制约束,加大了对气体污染物的惩罚力度。结合某石化企业的蒸汽动力系统实际情况建立了多周期运行优化数学模型,运用ICPPSO算法对其优化求解,得到了合理的单元配置、燃料选择和不同操作周期的动力输入、输出和购买蒸汽及环境成本的运行优化方案,并给出了降低包括环境成本在内的运行总成本的合理性建议。更多还原

【Abstract】 Steam power system (SPS) is an important part of the petrochemical enterprises, its security and stable operation are the basic of the process industrial long-period operation. Steam power system consumes a large amount of fuel and causes serious environment problem. Therefore, the optimization of the SPS operation and the reduction of operating costs, not only is an important way to improve efficiency for the process of industrial energy consumption, but also have important research significance to the sustainable development of human society.Steam power system in the petrochemical enterprises has its own complex operating characteristics. Understanding and analyzing deeply the characteristics is a premier to develop reasonable optimization programs for the operation of SPS. It is very important to establish a multi-level integration steam power system model of petrochemical enterprises for understanding deeply steam power system, guiding the activities of steam power system and achieving the overall optimization of energy systems of petrochemical enterprises. In this thesis, the multi-level modeling architecture is introduced, and the hierarchical model of steam power system, physical structure model and flow model are established. An integrated optimization mathematical model of steam power system including boiler, turbine, waste heat boilers and other major equipment, is established. Because of the shortcoming of traditional Particle swarm optimization with the slow convergence speed and weak convergence of global optimization, a new improved optimization algorithm-linear parameters of particle swarm optimization (ICPPSO algorithm) is developed. The algorithm predigests the constraint handling and transforms the constraint problem to unconstraint. Using the improved PSO algorithm to optimize the solution of the case in literature and practical case, the results show that the optimization speed of ICPPSO is higher than that of other optimization methods, and the optimized program can reduce operational costs largely. The results also show that the algorithm has good practicality and effectiveness.The variations of petrochemical enterprise’s production capacity, market demand and seasonal alternation cause to different needs of steam and power in different periods and result in frequent start-up and shut-down issues of boiler and turbines. These operations not only increase the total operational cost, but also have very important impact on equipment life. Therefore, the model based on previous research on equipment start-up and shut-down cost is revised, In the thesis, when the start-up and shut-down time of boiler and gas turbine is considered, the models in the literatures are revised on the mathematic meaning. On the contrary, when the time is taken over, two revised programs are proposed. One program is to divide total time into three stages:equipment start-up time, equipment uptime and equipment shut-down time; the other revises the logic constraint of equipment start-up period early and delays shut-down period. Combined the steam power system of a petrochemical enterprise, a optimization mathematic model is developed and solved by adopting the ICPPSO algorithm with solving strategies by step, and two reasonable optimization programs are reached and the corresponding total operation cost decrease by 1.4% and 2.3% respectively. The results show that the revised model has not only mathematic meaning, and but also make the operation of SPS more near to ideal conditions and has good reference on the problem with the transit scheduling.China’s energy situation is subject to dual constraints of economic growth and environmental protection. With the development of energy shortage and environmental pollution, the energy problem becomes more serious. An optimization model of petrochemical steam power system in different operation period including the environmental cost is proposed, In the model, the pollutant emission and the pollutant emission reduction factor are considered, and the constraint of pollutant emission is introduced and the penalty on air pollutants is enhanced. Combined the SPS of a petrochemical enterprise, the model is solved by adopting ICPPSO algorithm and a reasonable operation program is obtained. The optimization result demonstrates different unit configuration and fuel selection. Furthermore, the operation programs including power input, output, and steam purchased in different periods will be different even same fuel choices whether the environmental cost is considered. In the end, some reasonable advice is proposed to decrease total operational cost including environmental cost.更多还原