Influence of Design Margin on Operation Optimization and Control Performance of Chemical Processes

Operation optimization is an effective method to explore potential economic benefits for existing plants. The m.aximum potential benefit from operationoptimization is determined by the distances between current operating point and process constraints, which is related to the margins of design variables. Because of various ciisturbances in chemical processes, some distances must be reserved for fluctuations of process variables and the optimum operating point is not on some process constraints. Thus the benefit of steady-state optimization can not be fully achied（ed while that of dynamic optimization can be really achieved. In this study, the steady-state optimizationand dynamic optimization are used, and the potential benefit-is divided into achievable benefit for profit and unachievable benefit for control. The fluid catalytic cracking unit （FCCU） is used for case study. With the analysis on how the margins of design variables influence the economic benefit and control performance, the bottlenecks of process design are found and appropriate control structure can be selected.

Optimization of the seismic processing phase-shift plus finite-difference migration operator based on a hybrid genetic and simulated annealing algorithm

Although the phase-shift seismic processing method has characteristics of high accuracy, good stability, high efficiency, and high-dip imaging, it is not able to adapt to strong lateral velocity variation. To overcome this defect, a finite-difference method in the frequency-space domain is introduced in the migration process, because it can adapt to strong lateral velocity variation and the coefficient is optimized by a hybrid genetic and simulated annealing algorithm. The two measures improve the precision of the approximation dispersion equation. Thus, the imaging effect is improved for areas of high-dip structure and strong lateral velocity variation. The migration imaging of a 2-D SEG/EAGE salt dome model proves that a better imaging effect in these areas is achieved by optimized phase-shift migration operator plus a finite-difference method based on a hybrid genetic and simulated annealing algorithm. The method proposed in this paper is better than conventional methods in imaging of areas of high-dip angle and strong lateral velocity variation.

Optimal design of sintered Ce_9Nd_(21)Fe_(bal)B_1 magnets with a low-melting-point (Ce,Nd)-rich phase

A systemic investigation was done on the chemistry and crystal structure of boundary phases in sintered Ce9Nd21FebalB1 （wt%） magnets. Ce2Fe14B is believed to be more soluble in the rare-earth （RE）-rich liquid phase during the sintering process. Thus, the grain size and oxygen content were controlled via low-temperature sintering, resulting in high coercivity and maximum energy products. In addition, Ce formed massive agglomerations at the triple-point junctions, as confirmed by elemental mapping results. Transmission electron micros- copy （TEM） images indicated the presence of （Ce,Nd）Ox phases at grain boundaries. By controlling the composition and optimizing the preparation process, we successfully obtained Ce9Nd21FebalBx sintered magnets; the prepared magnets exhibited a residual induction, coerciv- ity, and energy product of 1.353 T, 759 kA/m, and 342 kJ/m3, respectively.

Optimal design of left-lane line extensions considering non-yielding maneuvers at the beginning of the permitted phase

In order to restrict non-yielding maneuvers of left-turning vehicles,an optimal design of left-lane line extensions is proposed to solve the problem.A field observation was conducted to collect a data set of left-turning vehicles at the beginning of a green phase at two similar intersections(one with a permitted phase and the other with a protected phase).The comparative analysis shows no significant difference in the speed distribution using either a permitted phase or a protected phase,but it reveals that a permitted phase can lead to a larger acceleration when the left-turn vehicles pass through the conflict points.Those indicate the existence of non-yielding maneuvers of left-turn vehicles at signalized intersections with a permitted phase.Optimal designed left-lane line extensions contain two types of segments,circular curves and transition curves,and they are only related to four geometry parameters of an intersection.The proposed method is easy to use and it can offer reference for intersection channelization and traffic organization.

Adaptive optimization of agile organization of command and control resource

Adaptive optimization is one of the means that agile organization of command and control resource （AOC2R） adapts for the dynamic battlefield environment. A math model of the adaptive optimization of AOC2R is put forward by analyzing the interrelating concept and research. The model takes the adaptive process as a multi-stage decision making problem. The 2-phases method is presented to calculate the model, which obtains the related parameters by running the colored Petri net （CPN） model of AOC2R and then searches for the result by ant colony optimization （ACO） algorithm integrated with genetic optimization techniques. The simulation results demonstrate that the proposed algorithm greatly improves the performance of AOC2R.

Separation process study of liquid phase catalytic exchange reaction based on the Pt/C/PTFE catalysts

The liquid phase catalytic exchange(LPCE) reaction is an effective process for heavy water detritiation and production of deuterium-depleted potable water. In the current study, hydrophobic carbon-supported platinum catalysts(Pt/C/PTFE) with high efficiency as reported previously for LPCE were prepared and comprehensive performance evaluation method is applied to evaluate the separation behaviors of LPCE systematically. Experimental results indicate that the optimum reaction temperature of 60–80℃ and the molar feed ratio G/L of 1.5–2.5 would lead to higher separation efficiencies. As to the packing method, a random packing mode with a packing ratio of hydrophobic catalysts 0.25 is recommended. In addition, thermodynamic analysis corresponds well with experimental results under lower temperature and G/L, while the suppression of kinetic factors should not be neglected when T > 80℃ and G/L > 1.5.

Study on Operating Characteristics of Power Plant with Dry and Wet Cooling Systems

The represent paper will study the performance of the power plant with the combination of dry and wet cooling systems in different operating conditions. A thermodynamic performance analysis of the steam cycle system was performed by means of a program code dedicated to power plant modeling in design operating condition. Then the off-design behavior was studied by varying not only the ambient temperature and relative humidity but also several parameters connected to the cooling performance, like the exhaust steam flow rate, the air cooling fan load and the number of operating cooling water pumps and cooling towers. The result is an optimum set of variables allowing the dry and wet cooling system be regulated in such a way that the maximum power is achieved and low water consumption.

Torpedo Overall Multidisciplinary Design Based on Collaborative Optimization

A torpedo multidisciplinary design optimization (MDO) based on the collaborative optimization is proposed. Through decomposition and coordination, some problems in torpedo design such as multidisciplinary coupling, large data volume and complex data relationships can be solved. Taking aim at some complex problems in the torpedo design, such as computation in multidisciplinary design, organization, modeling and information exchange, the collaborative optimization methods based on approximate technology are presented. An example to increase the torpedo range is also given. It demonstrates that the method can converge quickly, has higher reliability and smaller data throughput, and is a very effective MDO method.

Single-arm phase II three-outcome designs with handling of over-running/under-running

Phase II clinical trials are commonly conducted as pilot studies to evaluate the efficacy and safety of the investigational drug in the targeted patient population with the disease or condition to be treated or prevented.When designing such a trial considering efficacy conclusions,people natu-rally think as follows:if efficacy evidence is very strong,a go decision should be made;if efficacy evidence is very weak,a no-go decision should be made;if the efficacy evidence is neither strong nor weak,no decision can be made(inconclusive).The designs presented in this paper match this natural thinking process with go/no-go/inconclusive outcomes.Both two-/three-stage designs are developed with three outcomes.Additionally,a general approach based on conditional error function is implemented such that new decision boundaries can be calculated to handle mid-course sample size change which results in either‘over-running’or‘under-running’and ensure the control of overall type I error.A free open-source R package tsdf that calculates the proposed two-/three-stage designs is available on CRAN.

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。

基于NOFRFs的非等温CSTR同步周期操作的评估优化

化学反应周期操作是利用反应非线性来提高系统性能指标的技术,对其评估与优化仍是现阶段工业应用亟待解决的关键问题.利用非线性输出频率响应函数对具有显著非线性的连续搅拌反应釜的入口浓度和入口温度同步周期操作进行评估.首先分析单个周期操作的输入对系统性能指标的单独贡献,然后确定使转化率最大化而应使用的最优相位差,最后分析入口浓度和入口温度同步周期操作的各阶交叉项的贡献.仿真结果表明:提出的方法优于传统的NFR方法和单变量NOFRFs方法,提高了周期操作评估的准确性;同时,在允许的工艺过程约束条件下进行了最优化设计,明显提高了反应物的转化率,为其他类型的化学反应过程周期操作评估和优化提供参考.

Multidisciplinary Design and Optimization of Multistage Ground-launched Boost Phase Interceptor Using Hybrid Search Algorithm

This article proposes a multidisciplinary design and optimization （MDO） strategy for the conceptual design of a multistage ground-based interceptor （GBI） using hybrid optimization algorithm, which associates genetic algorithm （GA） as a global optimizer with sequential quadratic programming （SQP） as a local optimizer. The interceptor is comprised of a three-stage solid propulsion system for an exoatmospheric boost phase intercept （BPI）. The interceptor＇s duty is to deliver a kinetic kill vehicle （KKV） to the optimal position in space to accomplish the mission of intercept. The modules for propulsion, aerodynamics, mass properties and flight dynamics are integrated to produce a high fidelity model of the entire vehicle. The propulsion module com- prises of solid rocket motor （SRM） grain design, nozzle geometry design and performance prediction analysis. Internal ballistics and performance prediction parameters are calculated by using lumped parameter method. The design objective is to minimize the gross lift off mass （GLOM） of the interceptor under the mission constraints and performance objectives. The proposed design and optimization methodology provide designers with an efficient and powerful approach in computation during designing interceptor systems.

上盖开发对车辆基地建设运维影响及优化设计

为了解决车辆基地上盖开发对盖下引起的建设和运维问题,需对其总平面布置、消防、交通、管线、减振降噪等各方面进行适应性调整和优化。通过分析车辆基地开发与不开发的差异性,以问题为导向,提出“一个中心、两个原则”的优化策略,即在保证盖下规模和功能的前提下,既为上盖开发创造良好条件,又确保盖下安全与环境,从选址、总平面布置、检修工艺、消防疏散、通风排烟、交通组织等各方面阐述优化设计思路,包括良好的站段关系、整合集约用地、采用新型检修设备、加强疏散和防排烟等,尽可能消解上盖开发带来的不利影响,从而实现盖上盖下相互协调、互利共赢。

基于信创环境的水利智搜优化设计与研究

为提高水利智搜数据采集效率、个性化推荐程度、协调运维能力、信创环境适配程度,向社会公众提供便捷高效的水利信息检索服务,结合核心技术自主可控的必然要求,研究运用数据采集、搜索推荐模型等智能化处理技术,进一步优化搜索算法,加强数据信息采集。同时,通过优化水利智搜平台设计,基于信创环境适配优化,采用集成式、场景式和交互式一体化数据呈现方式,提升支撑、统计分析、搜索和聚合能力,实现精准化推荐和协同化运维。基于信创环境的水利智搜优化设计与研究,可为水利行业智能化信息检索服务提供经验借鉴。

海上风电场运维设计方法

海上风电机组的运维成本占海上风电场全生命周期成本的很大部分,因此降低运维成本是保证海上风电经济效益的关键。分析目前海上风电场常用的运维方法,提出多种人员转运船、运维母船、直升机组合的运维方案。根据海上风电场的位置、运维方式、维修时间、运维计划等因素,以最低的运维成本为目标,建立海上风电场运维模型,得到多种运维方案的最优运维团队数量。以江苏某风电场为例,根据风电场的特点进行实际运维方案设计,得到最佳运维方案。

蜗壳式多通道气液旋流分离器结构优化及分离特性研究

为实现宽流量范围下气液两相流的高效分离,基于螺旋线理论设计出了一种新型蜗壳式多通道旋流分离器,并对其结构进行了优化设计。采用数值模拟方法将其与传统单入口气液旋流分离器进行性能对比,结果表明,新型蜗壳式多通道旋流分离器能有效解决单个入口所引起的空气核偏心现象及振荡问题,分离器内流场在不同入口含气率条件下均具有显著的轴对称特点,稳定性也更高,溢流带液量明显下降。虽然整体压损更大,但能够有效抑制二次流的产生,且在入口含气率越高时抑制效果越明显。

真空断路器弹簧操动机构的优化

真空断路器触头弹簧压力增大会导致断路器无法可靠合闸,四连杆结构在一定程度上会影响机构的出力特性和机械效益,进而影响断路器合闸的可靠与稳定。文中分析了真空断路器的动作原理,建立弹簧操动机构的数学模型;对机构中的凸轮轮廓、传动拐臂的角度和尺寸、连板与合闸滚子的尺寸参数进行优化,建立弹簧操动机构的仿真模型。动力学仿真表明,优化后的触头弹簧压力增大了58%(从1 700 N提升到2 686 N),仍能保证断路器操动机构可靠合闸。试验结果显示,触头弹簧压力为2 500 N时断路器触头能够可靠吸合,平均合闸速度降至0.68 m/s,弹跳时间缩短了18.4%,整体优化后的方案满足设计要求并具有良好的可靠性与稳定性。

基于正向解析式和多目标博弈优化算法的复杂装备体系优化设计方法

针对复杂装备体系(Complex Equipment System-of-systems,CES)优化设计中指标变量多、仿真依赖性强、易陷入局部最优的问题,提出一种基于正向解析式和多目标博弈理论(Multi-Objective Game Theory,MOGT)优化算法的CES优化设计方法。为提升CES优化设计的可解释性,构建任务级—能力级—装备级的评估指标体系;在此基础上,基于装备机理和效用函数表征装备评估指标与作战能力之间的正向映射关系,并利用相邻优属度熵权法计算各指标权重;通过正向解析式与约束条件建立多目标优化模型,并采用MOGT优化算法获得最佳优化结果。以某作战推演平台中防空攻防想定为例,开展算例评估与验证分析。研究结果表明,该方法能够实现CES中最优设计方案的求解,可显著提高设计效率和降低设计成本,为下一代装备发展论证、设计评估和作战试验提供了基础性工作。

基于Phase^2数值模拟的巷道支护参数优化研究

结合某矿回采巷道地质和技术条件,利用Phase^2数值模拟软件建立了不同锚杆支护参数的模型,通过分析巷道变形及应力分布特征,研究了不同锚杆间距和长度时巷道支护效果。结果表明:Phase^2数值模拟可以为巷道支护参数优化设计提供有效参考,优选支护方案效果良好,有效维护了巷道的稳定性。