S型焊接金属波纹管波片波形优化设计

S型焊接金属波纹管的波片波形结构对波纹管性能影响较大,目前尚无准确表达波形结构对波纹管性能影响的具体设计公式及理论。利用ANSYS Workbench软件建立了直边波形及斜边45°波形这2种S型焊接金属波纹管波片的二维模型,以提高波片压力刚度为优化设计目标,对模型进行静力学分析,确定了需要优化的波形结构参数及其取值范围。调用ANSYS Workbench响应面优化模块,设置优化参数与目标函数,求解得到优化设计后的波片波形结构参数数值。优化设计前后波纹管波片的应力分布和压力刚度对比表明,优化设计后的波片具有更高的压力刚度及更小的应力,优化后的斜边45°波形波片的力学性能更优。     

艾叶天然色素应用于苎麻纤维染色的研究

通过设计正交实验,得到优化的微波法提取艾叶色素的工艺为:料液比1∶15、微波功率560 W、处理时间2 min;对苎麻纤维进行阳离子改性,得到优化的改性工艺为:改性时间50 min、改性温度50℃、改性剂用量15 g/L、烧碱用量10 g/L;用艾叶色素上染阳离子改性的苎麻纤维,设计4因素3水平正交实验,采用一浴二步后媒染法进行染色实验,得到优化的染色工艺为:染色温度60℃、染色时间30 min、染液pH=5、艾叶色素提取液用量70 mL。     

Electromagnetic torque detecting for optimization of in-mould electromagnetic stirring in the billet and bloom continuous casting

ABSTRACT

In this paper, an electromagnetic torque device based on the theoretical model was established to determine the optimum frequency accurately and conveniently in billet and bloom continuous casting with in-mould electromagnetic stirring (M-EMS). Magnetic characteristics with M-EMS was investigated by numerical simulation and physical experiment with the application of electromagnetic torque device and gauss meter. In addition, the effects of stirring frequency with M-EMS on macro segregation and equiaxed crystal ratio were compared and analysed for 55SiCr with 150?mm?×?150?mm billet caster and BU with 310?×?360?mm bloom caster by a series of plant trials, respectively. The results showed that maximum magnetic flux density and maximum electromagnetic torque occurred with different frequency and same current in M-EMS, and central equiaxed crystal ratio and macro segregation has been significantly improved by optimum frequency with M-EMS.     

Simulation of temperature and reaction time prediction of the torrefaction process: case of hard-wood biomass

Direct utilisation of biomass for energy application is less profound due to the problems of low calorific value, high water content, and low grindability of biomass. For this reason, pre-heating treatment, sometimes called torrefaction, is necessary to improve the physical properties of biomass similar to ‘coal-like’ material. Unfortunately, only few comprehensive but simple theoretical models focused on hard-wood biomass were available to describe the torrefaction process. In this discussion, a simple proposed torrefaction model was developed and reported. The model has ability to estimate the yield of product mass and energy after the torrefaction process and determine the optimum conditions.     

Thermal energy and economic analysis of a PCM-enhanced household envelope considering different climate zones in Morocco

This study investigates the thermal energy potentials and economic feasibility of an air-conditioned family household-integrated phase change material (PCM) considering different climate zones in Morocco. A simulation-based optimisation was carried out in order to define the optimal design of a PCM-enhanced household envelope for thermal energy effectiveness and cost-effectiveness of predefined candidate solutions. The optimisation methodology is based on coupling Energyplus^® as a dynamic simulation tool and GenOpt^® as an optimisation tool. Considering the obtained optimum design strategies, a thermal energy and economic analysis are carried out to investigate PCMs’ integration feasibility in the Moroccan constructions. The results show that the PCM-integrated household envelope allows minimising the cooling/heating thermal energy demand vs. a reference household without PCM. While for the cost-effectiveness optimisation, it has been deduced that the economic feasibility is stilling insufficient under the actual PCM market conditions. The optimal design parameters results are also analysed.     

山药复合营养面条加工工艺研究

以新鲜山药泥、小麦粉为主要原料,牛肉、胡萝卜、脱脂纯牛奶和食盐为辅料,制备一款营养丰富、无添加剂的新型山药复合营养面条。通过单因素试验、正交试验和感官评价,筛选山药复合营养面条配方;通过物性指标、微观结构确定山药复合营养面条的最佳配方为:山药泥35%、牛肉∶胡萝卜质量比为1∶1、脱脂纯牛奶3%和食盐2.5%。     

大通煤业主斜井带式输送机设计变更及工艺优化

本文基于大通煤业矿井兼并重组整合项目初步设计,结合矿井配套选煤厂的建设情况,利用现有的带式输送机,重新优化了主斜井带式输送机设计方案,并对优化方案的难点提出了解决方法,为同类型矿井的改造设计提供了参考。     

断层应力区巷道顶板支护优化设计

1208运巷在过F4断层时,巷道顶板出现破碎、下沉以及局部冒顶现象,不仅降低了巷道掘进效率,而且威胁施工安全。通过分析原巷道支护设计存在的主要问题,对原支护进行优化,提出了“注浆锚棚+纵向桁架锚索”等联合支护措施。通过实际应用效果观察发现,支护设计优化后,加强了顶板稳定性,防止了顶板冒落事故发生。     

Loss cost reduction and power quality improvement with applying robust optimization algorithm for optimum energy storage system placement and capacitor bank allocation

Power losses cause the underutilization of distributed generation (DG) units in addition to the cost increasing in microgrid. Minimizing these losses has been focused in many papers. Using energy storage system (ESS) is a crucial solution for loss reduction. ESS can balance the power exchange in on-peak times where its location and size optimization can improve the microgrid efficiency and reduce the loss cost significantly. Moreover, to ensure the power quality by improving the voltage profile, capacitor bank can be installed optimally on some buses. Optimization of size and location of the capacitor bank can enhance the reactive power that is leading to power loss reduction. In other words, the capacitor bank is applied to compensate the total reactive power and consequently, the current is reduced that results in power loss reduction. In this article, the problem is defined as the optimum location and size of ESS and capacitor bank in the microgrid. Due to the complexity of the problem in many options for selecting the buses to implement these elements (ESS and capacitor bank), robust approach using the particle swarm optimization algorithm and general algebraic modeling system are applied for optimization process. In addition, the uncertainty of renewable DGs such as photovoltaic and wind turbine is modeled by probability density functions and Monte-Carlo is used for selecting more probable cases in optimization processes. The results show the loss cost reduction and improvement in voltage and power profile with less fluctuations and more stability.     

1×7-15.2/1860 MPa钢绞线用盘条优化研究

通过对1×7-15.2/1860 MPa钢绞线强度分析,对其所用原料盘条的规格、强度、拉拔道次的选择进行分析讨论,提供最优化的原料选择方案。