燃机电厂9F型机组热电负荷优化分配研究

电厂热电负荷优化分配是指在全厂总调度负荷下,根据各机组的热力性能确定各机组应承担的热电负荷,使得全厂效益最大或能耗最小的一种最优化问题.不同于燃煤热电厂,燃机电厂9F型机组由于设计为燃气轮机加蒸汽轮机的组合方式运行,因此在联合循环热力性能模型建立上较为复杂.提出了将余热锅炉新蒸汽参数作为中间变量,建立了机组天然气燃料消耗与电负荷、热负荷之间的关系模型,确定了优化计算的目标函数和边界约束条件,并采用非线性规划方法求解.模拟与实际运行结果均表明,该优化分配方法能有效降低燃机电厂燃料消耗水平,可以为同类型燃机电厂热电负荷优化分配提供参考.     

基于工程实际的锅炉热力性能计算

将影响锅炉热力性能的热工参数和包括制造误差、安装误差在内的结构参数视为设计变量,应用数理统计和概率论分别给出了确定设计变量分布的计算方法和锅炉达到额定蒸发量时的概率算法,同时进行了工程实例的计算和分析。结果表明,采用本文法后的锅炉达到额定蒸发量的概率下降很多,为此本文提出了改进锅炉设计和优化达到额定蒸发量概率的设计和计算方法。本算法更符合工程实际,拓宽了锅炉热力性能的评价方法。     

应用遗传算法优化设计微型燃气轮机原表面换热器

提出将热力性能设计与遗传算法搜索过程相结合的方法.对适用于100 kW微型燃气轮机的人字形交错波纹板式原表面换热器进行结构优化,分别以重量最轻和换热紧凑度/重量最大作为目标函数,把换热器芯体外形尺寸和换热表面结构尺寸作为待寻求最佳值的优化变量进行优化.遗传算法程序采用二进制编码,锦标赛选择,均匀交叉和单点变异,并采用基...     

给水泵汽轮机变速控制系统调节器参数的优化

对大型热力电站给水泵汽轮机变速控制系统调节器的参数的优化问题作了大量的仿真试验研究。提出的目标函数和优化域的设计思想在仿真研究中,证实了能使系统的动态特性得到改善,提高了系统的跟随特性、稳定性和快速性;所提供的多变量寻优为基础,单变量寻优为线索的多目标分步优化的设计思想和寻优程序,能比较迅速准确地求得调节器参数的优化域。这对于改进系统的运行性能和系统设计有着十分重要的意义。     

锅壳式燃油燃气锅炉的一体化辅助设计探讨

针对锅壳式燃油燃气锅炉的一体化设计概念进行探讨，对设计人员如何编制完成锅炉热力、阻力、强度等系列计算的程序配套辅助设计具有一定的参考价值。     

基于BP神经网络和分解技术的汽轮机叶片可靠性反求设计

汽轮机叶片可靠性反求设计旨在确定叶片未知概率设计参数以满足给定的可靠度要求.针对叶片功能函数为随机变量隐性函数的情况,提出了基于有限元、BP神经网络和分解技术的可靠性反求设计方法,该方法将有限元和BP神经网络相结合以构造功能函数与随机输入变量之间的近似解析表达式,运用分解技术,将求解随机设计参数的全局优化问题分解为主问题和子问题,通过子问题直接调用标准优化工具箱得到可靠性指标,并运用分解迭代技术对主问题求解,从而得到随机设计参数及目标可靠性指标对各随机变量的敏感性.以某实验台汽轮机等直叶片为例,阐述了该方法的具体实施过程.该方法数学描述简单,并可直接应用标准优化程序,成功地解决了隐性功能函数下叶片可靠性反求设计,具有较好的工程应用价值.     

基于VB的常规超临界Π型锅炉热力计算程序的研究

本文以超临界(Π型)锅炉为研究对象,面对锅炉运行调整中的实际需要,开发了一款基于Visual Basic的热力计算程序,为现场运行调整人员中提供了一套便利的热力计算工具。同时,通过该程序计算得出的实际性能参数能够与锅炉原设计性能参数进行深入对比,最终服务于锅炉的设计优化。     

浅谈卧式内燃锅壳式热水锅炉的设计

随着油，气生产的发展和城市环保要日益严格，燃油燃气锅炉将会有一定的发展，本文以哈依城市煤气的燃料而设计的ＷＮＳ２．８－０．７／９５／７０－Ｑ锅炉为例，着重叙述了卧式内燃锅炉的设计参数，并对卧式内燃锅炉设计中注意问题如螺纹烟管的综合性能的评价和优化分析，烟室前管板的裂纹和泄漏原因及防方与防泄措施，卧式内燃锅炉的易爆性及防爆门的设计，排污结构的设计等进行了深入细致的探讨，为我国设计，制造卧式内燃锅炉提     

基于DMO的风力机叶片细观纤维铺角优化设计

为进一步发挥复合材料铺层参数的可设计性潜力,提出融合离散材料优化法与遗传算法的叶片铺层角度优化方法.构建以细观单元铺层角度为设计变量、刚度最大为目标函数、应力最小为约束条件的叶片细观纤维铺层角度优化数学模型.应用Python语言编写算法求解程序,并与Abaqus软件交互进行求解,得到叶片各单元各层优化的铺层角度、铺层顺...     

燃油气中心回燃式锅炉前管板管端裂纹原因分析与改造方案

针对某用户的中心回燃式燃油气蒸汽锅炉在使用过程中前管板上连接的烟管频发管裂现象,探讨了管裂形成的原因,并且提出了改造措施,降低了前管板处的烟温,改善了前管板和烟管连接处的应力状态,实现了锅炉安全、高效地运行,对今后类似锅炉的设计和使用具有一定的参考意义。     

Performance assessment and optimization of an integrated solid oxide fuel cell-gas turbine cogeneration system

The combined solid oxide fuel cells and gas turbine (SOFC/GT) system is known to be a potential alternative for distributed power generation. In this paper, a novel SOFC/GT based cogeneration system, which integrated a transcritical carbon dioxide cycle (TRCC) with a LNG cold energy utilization system is proposed. A mathematical (zero-dimensional) model is developed to analyze the co-generation system performance from the perspective of thermodynamic (energy and exergy) and economic costs. The main parameters of the system are chosen to analyze their effects on thermodynamic performance. The results show that the current system can achieve 64.40% thermal efficiency and 62.13% exergy efficiency under given conditions, and can further improve efficiency through parameter optimization. Finally, the multi-objective optimization program using NSGA-II (Non-dominated Sorting Genetic Algorithm II) is used to obtain the optimal value of the system design parameters. In the multi-objective analysis, the thermodynamic efficiency and economic cost of the system are considered as objective functions. The optimization results show that the final optimized design selected from the Pareto front can achieve 63.08% thermal efficiency and 61.10% exergy efficiency, respectively.     

一种小型立式燃油锅炉的改造及实验研究

从目前立式燃油锅炉的发展现状出发,针对某小型立式燃油锅炉热效率不高,NO_x排放偏高的缺点,提出了相应改造方案,建立传热模型分析改造前后炉内燃烧与传热过程,并通过实验进行相关测试研究。经过分析和实验,结果表明:通过在炉膛中加装内炉胆,强化了燃烧与传热过程,提高了热效率,并改善了烟气排放;改造后的燃油锅炉炉膛温度分布均匀,无明显高温区,过量空气系数由1.10降低至1.05以下,NO_x排放降低25%以上,排烟温度明显降低,热效率提高2个百分点左右,以上均证明了该改造方案的可行性。     

Structural optimal design of a swing vane compressor

In this paper, a novel swing vane rotary compressor (SVC) was introduced, which had significant advantages—simple mechanism, reduced frictional loss, reliable operation, and a comparatively higher compression ratio. Based on the swing vane compressor geometry model, thermodynamic model and kinetic model, the mathematical model of optimum design was established, and further theoretical and experimental studies were conducted. The length of the cylinder, radius of the rotor and cylinder were defined as design variables and the reciprocal of EER as objective function. The complex optimization method was adopted to study the structure of the swing vane compressor. The theoretical model could provide an effective method for predicting compressor performance, which would also contribute to structural optimization of the SVC. The study shows that the friction loss of the compressor are greatly reduced by optimized design in a given initial value, and the EER increased by 8.55%.     

Thermoeconomic optimization of heat recovery steam generators operating parameters for combined plants

The optimization of the heat recovery steam generator (HRSG) is particularly interesting for the combined plants design in order to maximise the work obtained in the vapour cycle. A detailed optimization of the HRSG is a very difficult problem, depending on several variables. The first step is represented by the optimization of the operating parameters. These are the number of pressure levels, the pressures, the mass flow ratio, and the inlet temperatures to the HRSG sections. The operating parameters can be determined by means both of a thermodynamic and of a thermoeconomic analysis, minimising a suitable objective function by analytical or numerical mathematical methods. In the paper, thermodynamic optimization is based on the minimization of exergy losses, while the thermoeconomic optimization is based on the minimization of the total HRSG cost, after the reduction to a common monetary base of the costs of exergy losses and of installation.     

Optimization of the coupling of pressurized water nuclear reactors and multistage flash desalination plant by evolutionary algorithms and thermoeconomic method

Thermodynamic simulation programs are widely used for designing complex thermal systems, but most of them do not incorporate second law optimization techniques. In this study, an efficient optimization strategy is presented, which integrates three optimization techniques with a professional power plant and a cogeneration simulator so as to perform exergoeconomic optimization of complex thermal systems and generate combined pinch and exergy representations. This paper deals with the application of an evolutionary algorithm based on NSGA‐II to multi‐objective thermoeconomic optimization of coupling desalination plant with pressurized water reactor (PWR). In addition, one‐objective thermoeconomic optimization through genetic algorithm and mixed integer non‐linear mathematical programming methods has been applied for evaluation of multi‐objective optimization. The thermodynamic simulation of this plant has been performed in the THERMOFLEX simulator. An Excel Add‐in called THERMOFLEX link has been developed to calculate the exergy of each stream from THERMOFLEX simulation results. In addition, a computer code has been developed for thermoeconomic and improved combined pinch–exergy analysis in the MATLAB environment. Also, multi‐objective and one‐objective evolutionary algorithm optimization has been performed in MATLAB and one‐objective mathematical programming has been performed in LINGO software. Both the design configuration and the process variables are optimized simultaneously. The optimization algorithm can choose among several design options included in a superstructure of the feed water heaters and multistage flash desalination in a dual‐purpose plant. For the assumptions and simplifications made in this study, a 3000 MWh PWR power plant similar to Bushehr power plant has been considered. Copyright © 2008 John Wiley & Sons, Ltd.     

基于富氧燃烧的回转式加热器优化设计

富氧燃烧技术是控制电站锅炉大气污染物排放的新型方法。针对采用该系统的燃煤电站锅炉CO2预热问题,建立了加热CO2的回转式预热器的数学模型,以换热器的直径、蓄热部分的高度、烟气以及CO2的流通面积比、转子的转速5个特征值为设计变量,年运行费用最低为目标函数,应用MATLAB实现了四种工况下CO2预热器的优化设计。结果表明,对于1025 t/h燃煤锅炉,烟气中CO2浓度为84%~88%时预热器能经济运行,且偏离最优点时对年运行费用影响较小,因此要求锅炉运行中再循环烟气量应该控制在一定的范围内。     

Design and multi-objective optimization of heat exchangers for refrigerators

In this study, a detailed thermodynamic model for a refrigerator based on an irreversible Carnot cycle is developed with the focus on forced-air heat-exchangers. A multi-objective optimization procedure is implemented to find optimal design values for design variables. Minimizations of energy consumption and material cost were the two objectives considered. Since these objectives are conflicting, no single design will satisfy both simultaneously. The result of this research is a set of multiple optimum solutions, which are called ‘Pareto optimal solutions’. Air and refrigerant side correlations were combined with an elemental approach to model the heat exchangers. This paper presents a detailed design model development. A limited validation is presented with experimental test-data obtained from a typical household refrigerator. Detailed simulation models are typically complex and computationally demanding. An optimization algorithm requires several evaluations of such models. Response surface based metamodels for objective functions were used to save computational effort. A genetic-algorithm based optimization tool is used for multi-criteria optimization.     

船舶余热动力回收系统热力学参数及余热锅炉结构参数优化

本文对船舶余热动力回收系统分别以最小初投资和锅炉最小传热面积作为目标函数,针对三种不同管形和两种不同管子排列形式的锅炉结构进行了热力学参数及锅炉结构参数优化,并且同实例进行了比较,提出了更为合理的热力学及锅炉结构参数。     

Multi-Objective Optimization of an Inverse Trapezoidal-Shaped Microchannel

The microchannel with inverse trapezoidal cross section in a micro heat sink has been optimized using three-dimensional Navier–Stokes analysis and a multi-objective evolutionary algorithm. Thermal resistance and pressure drop were selected as objective functions to evaluate the performance of the microchannel heat sink. Three design variables related to the width, depth, and angle of the channel, respectively, were selected for optimization. Parametric study has been performed with the three design variables prior to the optimization to analyze the variation of objective functions with the design variables, and thus to determine the design space for the optimization. Using a finite-volume solver, Navier–Stokes and energy equations for laminar flow and conjugate heat transfer were solved for the constant mass flow rate of 0.000598 kg/s. Latin hypercube sampling was utilized to select the design points. A surrogate model for each objective function was constructed using the values of the objective function calculated at the design points. Pareto-optimal solutions were obtained to find the optimal designs of the microchannel. Pareto sensitivity analysis was performed for the design variables along the Pareto optimal front, and it was found that both the objective functions were most sensitive to the design variable that is related to the width of the microchannel.