Four-Objective Optimization of Irreversible Atkinson Cycle Based on NSGA-II

Abstract

Variation trends of dimensionless power density (PD) with a compression ratio and thermal efficiency (TE) are discussed according to the irreversible Atkinson cycle (AC) model established in previous literature. Then, for the fixed cycle temperature ratio, the maximum specific volume ratios, the maximum pressure ratios, and the TEs corresponding to the maximum power output (PO) and the maximum PD are compared. Finally, multi-objective optimization (MOO) of cycle performance with dimensionless PO, TE, dimensionless PD, and dimensionless ecological function (EF) as the optimization objectives and compression ratio as the optimization variable are performed by applying the non-dominated sorting genetic algorithm-II (NSGA-II). The results show that there is an optimal compression ratio which will maximize the dimensionless PD. The relation curve of the dimensionless PD and compression ratio is a parabolic-like one, and the dimensionless PD and TE is a loop-shaped one. The AC engine has smaller size and higher TE under the maximum PD condition than those of under the maximum PO condition. With the increase of TE, the dimensionless PO will decrease, the dimensionless PD will increase, and the dimensionless EF will first increase and then decrease. There is no positive ideal point in Pareto frontier. The optimal solutions by using three decision-making methods are compared. This paper analyzes the performance of the PD of the AC with three losses, and performs MOO of dimensionless PO, TE, dimensionless PD, and dimensionless EF. The new conclusions obtained have theoretical guideline value for the optimal design of actual Atkinson heat engine.

Power density analysis and multi-objective optimization of an irreversible Otto cycle

“…有限时间热力学 应用于实际热力循环的性能分析和优化，取得了很大的进展。运用 有限时间热力学理论分析 Otto 循环的性能，是改进和优化 Otto 循环热机的新技术，并且发 展了研究 Otto 循环的新方法。在工质比热随温度恒定 [22][23][24][25][26][27][28][29][30][31][32][33][34] 、比热随成分变化 [35,36] 和比热随 温度变化 [37][38][39][40][41][42][43] 时，许多学者在考虑不同损失的条件下，对 Otto 循环的功率、效率和生态学 函数等目标函数的性能进行了研究。 除功率、效率和生态学函数等目标函数外，Sahin 等 [44,45] 引入了一种新的目标函数--功率密度(循环输出功率与最大比容之比)作为新的优化准则， 对可逆 Joule-Brayton 循环进行 了优化，发现了热机在最大功率密度准则下的热效率高于最大功率准则下的热效率，并且前 者设计的热机尺寸更小；陈林根等 [46] 将功率密度这一目标函数引入到可逆 Atkinson 循环最 优性能的分析中；Gumus 等 [47] 将最大功率密度准则应用于可逆 Otto 循环的性能优化中，并 将优化结果与最大功率和最大有效功率准则下得到的优化结果进行了比较；Zhao 和 Xu [48] 考虑了传热和摩擦损失，在工质比热随温度非线性变化时对不可逆 Otto 循环的功率、效率 和功率密度等性能的进行了研究，并将其研究结果与 Atkinson 和 Miller 循环下得到的结果 进行了比较。 以上研究工作均集中在循环性能的单目标优化，但由于各个目标函数之间存在矛盾，为 了协调目标函数间的关系，许多学者开展了循环性能的多目标优化 [49][50][51][52][53][54][55][56][57][58][59] 研究工作。戴东东等 基金项目：国家自然科学基金(51779262)和武汉工程大学研究生教育创新基金项目(CX2020038)资助. 通讯作者：陈林根，Email: lingenchen@hotmail.com, lgchenna@yahoo.com [49]…”

“…un 等 [51] 对单 ，对燃料电池 了多目标优化 ng 等 [54,55] [50] 和两级 池-Braysson 化；Li 等 [53] 和 Chen 等 [56] 数进行了多目 等 [58] 研究了…”

Performance Optimizations with Single-, Bi-, Tri-, and Quadru-Objective for Irreversible Diesel Cycle

“…Ahmadi et al [ 40 , 41 , 42 , 43 ] carried out MOO for an irreversible radiant heat engine [ 40 ], fuel cell combined cycle [ 41 , 42 ], and Lenoir heat engine [ 43 ] with different objective functions. Shi et al [ 44 ] and Ahmadi et al [ 45 ] performed MOO of the Atkinson cycle when the working fluid’s specific heats were constants [ 44 ] and varied with temperature non-linearly [ 45 ]. Gonzalez et al [ 46 ] performed MOO on , , and entropy generation of an endoreversible Carnot engine and analyzed the stability of the Pareto frontier.…”

Modeling and Performance Optimization of an Irreversible Two-Stage Combined Thermal Brownian Heat Engine

“…FTT theory has been applied for performance optimization of various macro energy systems. The applications of FTT include many aspects and the two major aspects are optimal configurations [ 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 ] and optimal performances [ 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 ,…”