共查询到19条相似文献,搜索用时 93 毫秒
1.
2.
3.
4.
5.
在对换热网络分级超结构及其数学模型分析的基础上,对网络综合优化问题进行了研究.针对普通遗传算法及其它优化算法无法保证网络优化质量和效率的缺点,对遗传算法进行了改进,提出了换热网络隔代强制进化遗传算法。该方法将换热网络结构信息转化为种群中染色体信息,利用种群的进化实现网络结构的优化,在进化过程中使用隔代强制策略,使种群向更优方向稳步进化,保证各代优化结果的有效性,降低最优群体的生成代数,并利用最优个体保存技术记录优化过程中最佳换热网络结构。采用此方法对具体换热网络实例进行了优化综合,结果表明:隔代强制进化遗传算法能在网络优化过程中避免早熟收敛而陷入局部最小点的现象,使搜索质量和效率得到有效提高。用隔代强制进化遗传算法对有分流和无分流换热网络进行优化综合,均能获得综合性能良好的网络结构。 相似文献
6.
能量回收换热网络的构造与优化 总被引:1,自引:0,他引:1
本文采用系统合理用能的方法,针对一具有多生产线、多产品的联合企业,在进行系统用能现状分析的基础上,找出系统用能不合理的主要薄弱环节并结合工艺过程寻求出可能的回收环节,由此进行薄弱环节与回收环节之间的换能网络的构造。提出了最大能回收模型,得出以换热网络出口物流温度作为优化变量,当分别达到最大能和回收目标时,该优化变量在两种目标下取值相同,这对能量回收换热网络的设计具有指导意义。 相似文献
7.
8.
9.
提出了具有无分流结构特征的换热网络同步综合数学规划方法。该方法以分级超结构模型为基础,在工艺物流匹配过程中只考虑无分流串级结构,建立混合整数非线性数学模型进行优化求解。无分流同步综合模型中的非线性项只存在于目标函数中,约束条件集合是由线性等式和不等式约束组成的,且相对于有分流同步综合模型,决策变量个数显著降低,模型的鲁棒性较好,模型复杂度降低,求解难度减小。此外,根据此模型的特点,提出了一种双层随机优化算法对模型进行求解,外层利用遗传算法搜索最优结构,内层则利用粒子群算法求解连续非线性数学规划子问题。两个典型算例用来验证方法的可行性和有效性。 相似文献
10.
针对微分进化(Differential Evolution,DE)算法应用于换热网络优化存在局部搜索能力不足、收敛速度慢和求解精度低等问题,提出一种混合微分进化(Hybrid Differential Evolution,HDE)算法。当DE算法的变异、交叉和选择操作不再使种群的最优值继续进化时,加入梯度操作使当前种群的最优个体趋向更好的解。为了防止算法早熟收敛,当种群的多样性低于设定的阈值时,引入迁移操作,在最优个体附近区域重新生成新的个体并以此替换旧的个体,增强算法的种群多样性。通过算例验证了该算法可以有效适用于换热网络的优化过程,具有更强的局部搜索能力,更快的收敛速度和更高的优化效率。 相似文献
11.
基于感知器模型本文提出一种换热器网络优化新算法,在遗传迭代过程中,依据目标函数的适应值,该算法不断调节感知器的权值,使感知器以随机方式搜索网络拓扑结构和运行参数。经过本文的计算表明:这一算法对于多维、多峰、非凸函数也具有很好的适应性,能够有效地克服传统方法(混合整数非线性优化)的不足之处。 相似文献
12.
A model is developed to simulate a cross‐flow heat exchanger, including fins, in the wall of which thermoelectric generators are sandwiched. Such a system could be used for waste heat recovery. The model is used to optimize the device based on several objective functions: total volume, total number of thermoelectric modules, power output, and pumping power. The design variables are the local distribution of modules and of current, the shape of the fins, and the division of the heat exchanger in sub‐channels. Pareto fronts are achieved with a multi‐objective genetic algorithm, and are presented here. The results show that the number of sub‐channels in the heat exchanger has a larger impact on the overall performance than the fin geometry for this particular problem. Also, the net power output is mostly correlated to the number of thermoelectric modules, and less to the heat exchanger volume. Various relations between the different competing objectives are shown and analyzed. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
13.
14.
This paper presents a procedure for the design of the components of a heat exchanger network (HEN). The procedure first uses pinch analysis to maximize heat recovery for a given minimum temperature difference. Using a genetic algorithm (GA), each exchanger of the network is designed in order to minimize its total annual cost. Eleven design variables related to the exchanger geometry are considered. For exchanger involving hot or cold utilities, mass flow rate of the utility fluid is also considered as a design variable. Partial or complete condensation of hot utility fluid (i.e., water vapor) is allowed. Purchase cost and operational cost are considered in the optimization of each exchanger. Combining every exchanger minimized cost with the cost of hot utility and cold utility gives the total cost of the HEN for a particular ΔTmin. The minimum temperature difference yielding the more economical heat exchanger network is chosen as the optimal solution. Two test cases are studied, for which we show the minimized total cost as a function of the minimum temperature difference. A comparison is also made between the optimal solution with the cost of utilities and without it. 相似文献
15.
Thermal modeling and optimal design of compact heat exchangers are presented in this paper. ε–NTU method was applied to estimate the heat exchanger pressure drop and effectiveness. Fin pitch, fin height, fin offset length, cold stream flow length, no-flow length and hot stream flow length were considered as six design parameters. Fast and elitist non-dominated sorting genetic-algorithm (NSGA-II) was applied to obtain the maximum effectiveness and the minimum total annual cost (sum of investment and operation costs) as two objective functions. The results of optimal designs were a set of multiple optimum solutions, called ‘Pareto optimal solutions’. The sensitivity analysis of change in optimum effectiveness and total annual cost with change in design parameters of the plate fin heat exchanger was also performed and the results are reported. As a short cut for choosing the system optimal design parameters the correlations between two objectives and six decision variables with acceptable precision were presented using artificial neural network analysis. 相似文献
16.
17.
18.