Cost and Entropy Generation Minimization of a Cross-Flow Plate Fin Heat Exchanger Using Multi-Objective Genetic Algorithm
Cost and Entropy Generation Minimization of a Cross-Flow Plate Fin Heat Exchanger Using Multi-Objective Genetic Algorithm
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DOI：
10.1115/1.4002599
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发表时间：
2011-02-01
影响因子：
--
通讯作者：
Dincer, Ibrahim
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文献类型：
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作者：
Ahmadi, Pouria;Hajabdollahi, Hassan;Dincer, Ibrahim
在目前的工作中，热建模进行紧凑型换热器的优化设计，以最大限度地减少成本和熵产生。在这方面，一个EST-NTU的方法被应用于估计的换热器的压降，以及有效性。翅片间距、翅片高度、翅片偏移长度、冷流长度、无流长度和热流长度被认为是六个决策变量。快速和精英非支配排序遗传算法（即，采用非支配排序遗传算法（Ⅱ）同时最小化熵产单位数和年总费用（初始投资和运行维护费用之和）。帕累托最优前沿的结果清楚地揭示了两个目标函数之间的冲突，熵产生单位的数量和总的年成本。它揭示了任何几何变化，减少熵产生单位的数量，导致总的年成本的增加，反之亦然。此外，为了预测板翅式换热器的优化设计，推导了熵产单元数与年总费用的关系式。此外，基于火用损失的换热器优化表明，不可逆性（如压降和冷热流温差大）是火用损失的关键因素。因此，更有效的热交换器导致具有更高总成本率的热交换器。最后，对板翅式换热器的最优熵产单元数和年总成本随决策变量的变化进行了敏感性分析，并给出了结果。[DOI：10.1115/1.4002599]
In the present work, a thermal modeling is conducted for optimal design of compact heat exchangers in order to minimize cost and entropy generation. In this regard, an epsilon -NTU method is applied for estimation of the heat exchanger pressure drop, as well as effectiveness. Fin pitch, fin height, fin offset length, cold stream flow length, no-flow length, and hot stream flow length are considered as six decision variables. Fast and elitist nondominated sorting genetic algorithm ( i.e., nondominated sorting genetic algorithm II) is applied to minimize the entropy generation units and the total annual cost ( sum of initial investment and operating and maintenance costs) simultaneously. The results for Pareto-optimal front clearly reveal the conflict between two objective functions, the number of entropy generation units and the total annual cost. It reveals that any geometrical changes, which decrease the number of entropy generation units, lead to an increase in the total annual cost and vice versa. Moreover, for prediction of the optimal design of the plate fin heat exchanger, an equation for the number of entropy generation units versus the total annual cost is derived for the Pareto curve. In addition, optimization of heat exchangers based on considering exergy destruction revealed that irreversibilities, such as pressure drop and high temperature difference between cold and hot streams, play a key issue in exergy destruction. Thus, more efficient heat exchanger leads to have a heat exchanger with higher total cost rate. Finally, the sensitivity analysis of change in the optimum number of entropy generation units and the total annual cost with change in the decision variables of the plate fin heat exchanger is also performed, and the results are reported. [DOI:10.1115/1.4002599]