Process design and intensification of multicomponent azeotropes special distillation separation via molecular simulation and system optimization

This work provides an overview of distillation processes,including process design for different distillation processes,selection of entrainers for special distillation processes,system integration and intensification of distillation processes,optimization of process parameters for distillation processes and recent research progress in dynamic control strategies.Firstly,the feasibility of using thermodynamic topological theories such as residual curve,phase equilibrium line and distillation boundary line to analyze different separation regions is discussed,and the rationality of distillation process design is discussed by using its feasibility.Secondly,the application of molecular simulation methods such as molecular dynamics simulation and quantum chemical calculation in the screening of entrainer is discussed for the extractive distillation process.The thermal coupling mechanism of different distillation processes is used to explore the process of different process intensifications.Next,a mixed integer nonlinear optimization strategy for the distillation process based on different algorithms is introduced.Finally,the improvement of dynamic control strategies for different distillation processes in recent years is summarized.This work focuses on the application of process intensification and system optimization in the design of distillation process,and analyzes the challenges,prospects,and development trends of distillation technology in the separation of multicomponent azeotropes.

Multidisciplinary Design Optimization of A Human Occupied Vehicle Based on Bi-Level Integrated System Collaborative Optimization

The design of Human Occupied Vehicle （HOV） is a typical multidisciplinary problem, but heavily dependent on the experience of naval architects at present engineering design. In order to relieve the experience dependence and improve the design, a new Multidisciplinary Design Optimization （MDO） method ＂Bi-Level Integrated System Collaborative Optimization （BLISCO）＂ is applied to the conceptual design of an HOV, which consists of hull module, resistance module, energy module, structure module, weight module, and the stability module. This design problem is defined by 21 design variables and 23 constraints, and its objective is to maximize the ratio of payload to weight. The results show that the general performance of the HOV can be greatly improved by BLISCO.

Integrated Building Envelope Design Process Combining Parametric Modelling and Multi-Objective Optimization

As an important element in sustainable building design, the building envelope has been witnessing a constant shift in the design approach. Integrating multi-objective optimization(MOO) into the building envelope design process is very promising, but not easy to realize in an actual project due to several factors, including the complexity of optimization model construction, lack of a dynamic-visualization capacity in the simulation tools and consideration of how to match the optimization with the actual design process. To overcome these difficulties, this study constructed an integrated building envelope design process(IBEDP) based on parametric modelling, which was implemented using Grasshopper platform and interfaces to control the simulation software and optimization algorithm. A railway station was selected as a case study for applying the proposed IBEDP, which also utilized a grid-based variable design approach to achieve flexible optimum fenestrations. To facilitate the stepwise design process, a novel strategy was proposed with a two-step optimization, which optimized various categories of variables separately. Compared with a one-step optimization,though the proposed strategy performed poorly in the diversity of solutions, the quantitative assessment of the qualities of Pareto-optimum solution sets illustrates that it is superior.

Multidisciplinary integrated design of long-range ballistic missile using PSO algorithm

In the case of the given design variables and constraint functions, this paper is concerned with the rapid overall parameters design of trajectory, propulsion and aerodynamics for long-range ballistic missiles based on the index of the minimum take-off mass.In contrast to the traditional subsystem independent design, this paper adopts the research idea of the combination of the subsystem independent design and the multisystem integration design.Firstly, the trajectory, propulsion and aerodynamics of the subsystem are separately designed by the engineering design, including the design of the minimum energy trajectory, the computation of propulsion system parameters, and the calculation of aerodynamic coefficient and dynamic derivative of the missile by employing the software of missile DATCOM. Then, the uniform design method is used to simplify the constraint conditions and the design variables through the integration design, and the accurate design of the optimized variables would be accomplished by adopting the uniform particle swarm optimization(PSO) algorithm. Finally, the automation design software is written for the three-stage solid ballistic missile. The take-off mass of 29 850 kg is derived by the subsystem independent design, and 20 constraints are reduced by employing the uniform design on the basis of 29 design variables and 32 constraints, and the take-off mass is dropped by 1 850 kg by applying the combination of the uniform design and PSO. The simulation results demonstrate the effectiveness and feasibility of the proposed hybrid optimization technique.

Digital Design of Virtual Prototype based on Multidisciplinary Design Optimization

In order to obtain digital design of complex mechanical product as optimal as possible in an efficient way,multi- discipline integrated design method is proposed,which integrates multidisciplinary design optimization (MDO) into digital design process to design virtual prototype (VP) efficiently.Through combining MDO and multi-body system dynamics,MDO integra- tion platform,which takes VP as the core,is constructed.Then automated MDO design of VP is realized and changes of mechani- cal design project can be expressed intuitively during MDO design process.The proposed approach is also demonstrated by using inte- grated analyzing flow of vehicle engineering design.The result shows that the method not only can feasibly realize the MDO of VP, but also can solve the optimization problem of vehicle multi-body system dynamic performance.It can be adopted to the digital de- sign of other complex system.

Research on CAD/CAE/MDO integrated system for nuclear valve products

In order to realize rapid response to performance-driven design for nuclear valve products, a rapid design platform is constructed by combining the structural features with the multi-characteristic optimization requirement, which integrates parametric design, multi-characteristic simulation, and multidisciplinary design optimization of nuclear power valves together. Through the integration of heterogeneous CAX/MDO software, such as UG, ANSYS and iSIGHT, the analytical efficiency is enhanced by coupling respective and unique advantage of various software systems, and the mutual coordination and information sharing are realized between the heterogeneous systems. The application example shows that the system is convenient operation that improves the automation in design and analysis on nuclear valves. The results can provide a practical and effective development method and technical reference of the integrated design system for valve products.

Integrated passage design based on extended free-form deformation and adjoint optimization

Inspired by the three-dimensional design of flow passages in turbomachinery,this study proposes the concept of integrated passage design.The capability of adjoint method for efficient optimization and the flexibility of the parameterization method based on extended free-form defor-mation have been considered to develop a feasible approach to design an integrated passage.This concept was applied to redesign a typical transonic fan,Rotor 67,and the results were analyzed by CFX.It is shown that the passage was adequately adjusted in all three dimensions and reduced the strength of shock wave and wake-induced flow.In particular,the secondary flow was appropriately reorganized and the corner separation was well controlled in the end wall region,leading to signif-icant improvements in adiabatic efficiency and diffusion.

Many-objective optimization for coordinated operation of integrated electricity and gas network

This paper develops a many-objective optimization model, which contains objectives representing the interests of the electricity and gas networks, as well as the distributed district heating and cooling units, to coordinate the benefits of all parties participated in the integrated energy system(IES). In order to solve the many-objective optimization model efficiently, an improved objective reduction(IOR) approach is proposed, aiming at acquiring the smallest set of objectives. The IOR approach utilizes the Spearman’s rank correlation coefficient to measure the relationship between objectives based on the Pareto-optimal front captured by the multi-objective group search optimizer with adaptive covariance and Lévy flights algorithm, and adopts various strategies to reduce the number of objectives gradually. Simulation studies are conducted on an IES consisting of a modified IEEE 30-bus electricity network and a 15-node gas network. The results show that the many-objective optimization problem is transformed into a bi-objective formulation by the IOR. Furthermore,our approach improves the overall quality of dispatch solutions and alleviates the decision making burden.

二次再热燃煤-捕碳-制甲醇系统集成设计与优化

针对碳捕集电厂的高能耗及CO_(2)的后续利用问题,设计了一种二次再热燃煤-捕碳-制甲醇一体化系统。以某1000 MW超超临界二次再热机组为例,采用动态自适应粒子群优化算法对所提系统参数进行优化计算,分析了碳捕集率和光电制氢成本等因素对系统性能的影响。结果表明:当碳捕集率为90%时,一体化系统的热效率相比燃煤-捕碳机组提高了6.62%,CO_(2)排放强度降低了4.45 g/(kW·h),净收益提高了33.42亿元;当碳捕集率在40%~90%内变化时,一体化系统的热效率能够稳定保持在49%以上;随着未来光电制氢成本的下降,一体化系统的净收益将显著提升。

三相CLLC谐振变换器磁集成平面变压器设计与优化

三相CLLC谐振变换器凭借其高效率、大容量、低器件应力等优势而受到广泛关注。然而,多相结构的磁性元件数量多、体积大,是制约功率变换器尺寸的主要因素。随着宽禁带(WBG)半导体器件的出现,功率变换器的开关频率显著提高,这也为印制电路板(PCB)绕组的使用提供了有利条件。与传统绕线式绕组相比,PCB绕组的扁平特性更适用于平面磁性元件。此外,由于高频带来的低电感需求也使得基于PCB绕组的平面磁性元件更有利于实现集成。该文提出一种新型的基于PCB绕组的电感和变压器的集成结构,详细分析磁心结构的磁路模型,并给出集成磁件的优化设计方法,最后通过搭建一台基于SiC器件的800 V/10 kW的实验样机进行验证。实验结果表明,该集成方案可有效减小变换器的体积和损耗,具有高功率密度和高效率。

面向乡村建筑分时分区用能需求的零碳综合能源系统设计优化

基于传统最大负荷原则设计的综合能源系统容量通常远大于建筑的实际用能需求,导致以户为单位的乡村综合能源系统设计缺乏针对性和适用性。该文通过现场调查和数值模拟的方法精细化乡村建筑的实际用能需求,基于农户用能行为制定4种用能策略。并构建考虑农户经济水平和零碳约束的综合能源系统设计优化模型,采用两阶段带精英策略的快速非支配排序遗传算法(Top-NSGA-II)进行多目标优化问题的求解,获得不同策略下的最佳设计方案。结果表明,与基于建筑全空间连续动态负荷的设计优化方案相比,基于分时分区用能需求的设计方案年总成本降低13.58%,系统购电比例降低7.89个百分点,实现全年净零碳排放。

铁路工程建设可持续供应链网络集成优化研究

随着国家对铁路工程项目可持续发展的日益重视,迫切需要先进且集成的供应链网络设计方案理论与方法来提高供应链效率、可持续绩效以及资源利用率。实施可持续供应链网络设计已成为实现铁路工程可持续发展的重要途径,而供应商选择、物流设施选址、路径规划、库存管理以及工程废弃物回收再利用等决策是铁路工程供应链管理的核心与关键问题。针对我国铁路工程建设供应链管理特点,从可持续视角研究铁路工程建设供应链网络设计集成优化问题,提出两阶段的求解框架:其中,第1阶段基于可持续指标体系运用模糊TOPSIS方法确定最佳供应商选择;第2阶段针对物流设施选址、库存控制策略与网络最佳流量分配的集成决策问题,构建了基于模糊规划的多周期多目标供应链网络集成决策优化模型。该优化模型考虑了运输过程的不确定性,以供应链总成本、碳排放量最小以及社会效益最大为优化目标。针对上述多周期多目标优化模型的特征,设计了改进的宽容分层序列算法进行求解。最后,基于我国丰雄商铁路工程建设项目进行案例研究,验证了上述求解框架与算法的有效性,并针对单位运价、单位运输碳排放量以及弃置率3个关键参数进行了敏感性分析。研究结果表明:1)批量折扣策略可以在联合采购中节省大量成本;2)运输模式与路径优化对系统的效率和可持续绩效有决定性影响;3)与管理学手段相比,推进新能源的使用是降低碳排放量最有效的措施;4)社会效益的提高不可避免地需要更高的成本,政府合理的补贴政策是提高企业积极性的关键举措;5)长远来看,铁路工程项目中的废弃物回收利用是实现可持续工程建设的重要途径,其技术和应用的发展都应受到重视。

多冗余模式下综合能源系统两阶段优化配置

在综合能源系统向复杂化、高耦合度发展的过程中,设备单元运行可靠性降低与高昂的设备运维成本问题难以忽视。针对上述问题,从内部配置结构优化的角度,将系统工程中主、被动冗余思路引入综合能源系统,完成子系统单元的冗余设计。提出了一种针对冗余设备逻辑最优工况匹配的两阶段流程,以实现全系统整年运行优化。从经济、能源和环境3方面建立评价指标,基于蜜獾算法对两建筑、四系统进行案例研究。结果表明:所提3种冗余系统均实现了可靠性与各性能指标的明显提升;主动冗余系统年度总运行成本最低,热备用系统可靠性表现最好,冷备用系统综合性能最佳。

基于耦合分析的热流系统协同设计

作为综合能源系统的一部分,热流系统通常在稳态假设下设计其物理系统,在此基础上设计控制器.这种方法忽略了系统与控制器设计间的耦合关系,导致系统暂态性能不佳.为此,本文提出一种协同设计方法,以系统总质量、熵产率以及控制效果为设计度量,基于热流系统数学模型及其熵产率模型,结合嵌套设计方法和同步设计方法完成系统设计.考虑到设计过程中设计参数多、变量范围大的问题,引入时间序列模式距离,构造相关度度量函数来分析物理系统与控制器之间的耦合关系,从而减少非耦合参数.同时,利用数据分析方法进一步缩小了待设计参数范围.为验证方法的有效性,以一个理想热流系统为设计实例,仿真结果表明,通过相关度度量函数及其数据分析,可以将设计参数个数减少66%,选取范围缩小26%.相比于传统顺序设计方法,经过协同设计方法设计的系统控制误差可减少29%,且设计控制器抗扰能力也优于频域方法和SIMC方法.

面向大规模物联网的无人机通信感知一体化能效优化算法

针对大规模物联网场景下无人机通信感知一体化系统存在的重复感知和能量受限等问题,提出了一种基于聚类算法的能效优化方案。该方案在满足无人机的移动性和感知能力约束下,通过联合设计无人机的三维轨迹和发射功率来最大化系统能效。由于该问题是非凸的,首先将其解耦为两个子问题,然后利用模拟退火算法和标准凸优化技术来求解无人机的悬停位置和飞行速度以获取最优轨迹,最后根据最优轨迹推导发射功率的闭合表达式,求得每个悬停位置的最优发射功率。与传统的二维和三维方案相比,所提基于聚类的能效优化方案在收敛速度提高4倍的基础上能提升20%~30%系统能效。

耦合加氢装置优化的多周期氢网络集成

当前环境法规日益严格,炼厂为提高产品质量需要深化加氢处理深度,但会显著增加氢气消耗。此外,当加氢装置处理量调整以及原油切换引起杂质含量波动时,加氢装置工况将会产生偏移,若不及时对新工况下的氢气使用进行优化,可能导致产品质量下降或造成氢气浪费。针对于此,提出耦合加氢装置优化的多周期氢网络集成方法。该方法第一阶段通过使用加氢精制装置操作参数优化模型获得不同场景下各装置的最佳操作参数,第二阶段综合多个优化后的操作场景集成氢网络。通过实例计算表明,基于所提出的优化方法能获得满足不同场景下的加氢精制装置的加氢需求、以更低的成本获得合格产品的氢气网络运行策略。

Application of CFD plug-ins integrated into urban and building design platforms for performance simulations:A literature review

The transformation of urban and building design into green development is conducive to alleviating resource and environmental problems.Building design largely determines pollutant emissions and energy consumption throughout the building life cycle.Full consideration of the impact of urban geometries on the microclimate will help construct livable and healthy cities.Computational fluid dynamics(CFD)simulations significantly improve the efficiency of assessing the microclimate and the performance of design schemes.The integration of CFD into design platforms by plug-ins marks a landmark development for the interaction of computer-aided design(CAD)and CFD,allowing architects to perform CFD simulations in their familiar design environments.This review provides a systematic overview of the classification and comprehensive comparison of CFD plug-ins in Autodesk Revit,Rhinoceros/Grasshopper,and SketchUp.The applications of CFD plug-ins in urban and building design are reviewed according to three types:single-objective,multi-objective,and coupling simulations.Two primary roles of CFD plug-ins integrated into the design process,including providing various micro-scale numerical simulations and optimizing the original design via feedback results,are analyzed.The issues of mesh generation,boundary conditions,turbulence models,and simulation accuracy during CFD plug-in applications are discussed.Finally,the limitations and future possibilities of CFD plug-ins are proposed.