共查询到18条相似文献,搜索用时 781 毫秒
1.
2.
3.
改进的混沌优化方法在电站机组负荷分配中的应用 总被引:7,自引:1,他引:7
利用搜索过程中的先验知识,提出了一种改进的变尺度混沌优化算法,对电厂机组负荷分配这一类高维、非线性问题进行寻优。该算法利用混沌运动的遍历性和随机性进行全局搜索,结合下降法思想在当前最优解的局部空间搜索,提高算法的收敛速度。通过罚函数,将非线性约束问题转化为非约束问题求解,在寻优操作过程中检验解的有效性。并采用目标函数中负荷取值区间判别方法,降低优化问题的规模,减少了计算次数。与传统遗传算法相比,改进的混沌优化算法获得了更好的效果。 相似文献
4.
5.
6.
7.
8.
9.
10.
模拟退火算法在水污染控制系统规划中的应用 总被引:4,自引:0,他引:4
阐述了模拟退火算法的工作原理及其实现技术,对其在水污染控制系统规划中的应用作了初步探讨,浙江某区域排放口优化问题的研究表明,模拟退火算法是一种全局最优化算法,只要优化参数选取合适,所得到的规划结果就比较接近实际情况,有利于水质规划工作。 相似文献
11.
《International Communications in Heat and Mass Transfer》2001,28(1):59-66
This paper presents an algorithm combining non-linear programming techniques with methods of solving initial value problems to solve a non-linear boundary value problem describing the temperature field in a parallel-flow multi-channel heat exchanger. The method is illustrated by an example of determining temperature profiles in a four-channel heat exchanger. The calculations are performed with the aid of the computer program Mathcad® 2000 Professional. 相似文献
12.
《Applied Thermal Engineering》2001,21(16):1675-1697
This work presents a systematic mathematical framework for scheduling the operation of multipurpose plants involving heat-integrated unit operations under fouling considerations. A salient characteristic of this problem is that the performance of each heat-integrated unit, which decreases with time due to fouling, can be restored to its initial state by performing cleaning operations. Based on a uniform time discretization, the overall problem is formulated as a mixed integer non-linear programming (MINLP) model. An iterative procedure is proposed for the solution of the resulting non-convex MINLP model, involving the solution of a series of mixed integer linear programming and non-linear programming subproblems. The optimization algorithm determines simultaneously: (i) the production schedule, (ii) the number of cleaning operations required along with their corresponding timings, (iii) the optimal utility utilization profile and (iv) the heat transfer medium flow rate profiles over time. An example problem is presented to illustrate the applicability of the proposed approach. It is proved that fouling considerations can significantly affect the production schedule as well as heat integration opportunities. 相似文献
13.
RWCE算法优化换热网络时,较大的优化步长能够在接受差解的作用下促进结构变异,从而有效地跳出局部最优解。但持续的大步长无法保留结构变异后新生成的、换热量较小的换热单元,影响结构进化效率。基于大步长与接受差解的关联性,提出了一种大步长与接受差解联动策略,将接受差解和采用大步长同频,仅当接受差解时才使用大步长,并必定接受大步长作用下的新结构,保证大步长对结构变异的促进作用,解决大步长作用下新生成单元难以保留的问题,全面提升结构进化效率。将大步长与接受差解联动策略应用于20sp和15sp算例,分别得到结果为1 395 389和1 511 551$/a的最优换热网络结构,性能较基础RWCE算法提升7.06%和1.69%,验证了该策略对提升算法结构进化效率的有效性。 相似文献
14.
Prabhata K. Swamee Nitin Aggarwal Vijay Aggarwal 《International Journal of Heat and Mass Transfer》2008,51(9-10):2260-2266
Heat exchangers are used in industrial processes to recover heat between two process fluids. Although the necessary equations for heat transfer and the pressure drop in a double pipe heat exchanger are available, using these equations the optimization of the system cost is laborious. In this paper the optimal design of the exchanger has been formulated as a geometric programming with a single degree of difficulty. The solution of the problem yields the optimum values of inner pipe diameter, outer pipe diameter and utility flow rate to be used for a double pipe heat exchanger of a given length, when a specified flow rate of process stream is to be treated for a given inlet to outlet temperature. 相似文献
15.
16.
Energy management of a fuel cell/ultracapacitor hybrid power system using an adaptive optimal-control method 总被引:1,自引:0,他引:1
Energy management of a fuel cell/ultracapacitor hybrid power system aims to optimize energy efficiency while satisfying the operational constraints. The current challenges include ensuring that the non-linear dynamics and energy management of a hybrid power system are consistent with state and input constraints imposed by operational limitations. This paper formulates the requirements for energy management of the hybrid power system as a constrained optimal-control problem, and then transforms the problem into an unconstrained form using the penalty-function method. Radial-basis-function networks are organized in an adaptive optimal-control algorithm to synthesize an optimal strategy for energy management. The obtained optimal strategy was verified in an electric vehicle powered by combining a fuel-cell system and an ultracapacitor bank. Driving-cycle tests were conducted to investigate the fuel consumption, fuel-cell peak power, and instantaneous rate of change in fuel-cell power. The results show that the energy efficiency of the electric vehicle is significantly improved relative to that without using the optimal strategy. 相似文献
17.
换热网络优化是典型的混合整数非线性问题,其整型变量(换热网络的结构)的组合情况对于其优化的走向以及局部最优解的质量具有至关重要的作用.分析了换热网络结构与性能之间的连续性特征;利用最速下降法对换热网络整形变量进行初步优化以确定合适的换热器数目,生成一系列连续变化的换热网络结构;以结构序列作为优化变量,借助换热网络性能连续性原理,将多维整型变量转换为一维连续变量,对整型变量进行启发式的连续性搜索.通过具体算例求解,该方法帮助优化过程跳出了局部最优的陷阱,并得到了较好的优化结果. 相似文献
18.
基于分级超结构换热器网络模型的特点,改进了计算温度分布的通用解方法,以遗传算法和模拟退火算法为主,以瞎子爬山优化算法以及一些特殊优化策略为辅,设计了相应的计算程序,它需要的计算机内存要比现有的其他方法小。实例证明,该方法可成功地应用于较大规模的换热器网络的优化,并得到比现有各种方法更优的结果。 相似文献