太阳能光热-光电中空纤维真空膜蒸馏系统理论与实验研究

自主设计并搭建了太阳能光热-光电中空纤维膜蒸馏系统,太阳能光热采用面积1.82 m²真空管集热系统,光伏发电采用面积1.63 m²多晶硅电池板。实验方面,研究了不同工况下,热料液在不同流动方式时膜通量的差异;研究了在不同跟踪方式下太阳辐照度对系统性能的影响。结果表明：料液在管程流动的膜通量大于壳程的膜通量,且进口料液温度取50~70℃之间为宜;自动跟踪下膜组件入口温度比非跟踪高2~3℃,可以延长膜蒸馏系统运行时间1~2 h,且在相同的自然环境下,自动跟踪方式最大膜通量8.89 kg/(m²·h)远高于非跟踪方式时4.26 kg/(m²·h)。理论方面,分析了以水为工质的中空纤维膜蒸馏的传热和传质过程,建立了传热传质理论计算数学模型;分析了辐照强度、膜表面温差、膜丝内表面传热系数、传热与传质通量的定量关系,计算了膜面温度与理论膜通量,对比了实验值与理论值。系统运行稳定,能量综合利用效率高,性能可靠,为工程应用奠定了理论和实验基础。     

分子蒸馏纯化姜精油工艺的响应面法优化研究

借助分子蒸馏技术来对超临界CO_2进行相应的萃取就可以获取姜油树脂,然后借助相关手段对其进行纯化处理后就得到了姜精油。以单因素实验过程中所涉及到的分子蒸馏的压力和温度作为中心复合设计变量,以α–姜烯含量和姜精油收率作为指标来实现对响应面法的优化。结果表明:分子蒸馏的压力、温度对姜精油中α–姜烯含量及纯化姜精油的收率有一定的影响。     

响应面法优化微波辅助水蒸气蒸馏法提取汉麻叶精油工艺

为推动汉麻资源的深度开发利用,提高汉麻叶的附加价值,采用微波辅助水蒸气蒸馏(MAHD)法提取汉麻叶精油。通过单因素实验和响应面法优化汉麻叶精油提取工艺,选取提取时间、料液比、微波辐射时间、微波功率为考察因素,以汉麻叶精油提取率为评价指标进行单因素实验,再进行响应面分析优化。结合提取工艺的实际可操作性和便利性,确定最佳提取工艺为提取时间8.7 h、料液比1∶8(g/mL)、微波辐射时间10 min、微波功率480 W,最终实际提取率为0.210%,与理论值0.213%相接近。MAHD法在汉麻叶精油提取方面,具有实用性和开发性。     

基于响应面法的齿轮注塑模冷却系统优化

以塑料齿轮注塑模的冷却水道为研究对象,选取水道孔径、水孔间距及水孔至模壁距离3个冷却水道设计参数为试验变量,以模壁温差为质量目标,运用响应面法Box-Behnken设计试验方案,利用Design-Expert软件分析试验结果,构建出试验变量与质量目标之间的二阶响应面模型,并对其进行迭代优化,得出模壁温差最小时的冷却水道设计参数组合。模拟验证表明,响应面法优化效果较好,能够显著降低模壁温差。在3个设计参数中,水孔间距和水孔至模壁距离对模壁温差的影响较显著。     

模拟生物油分子蒸馏的响应面法工况优化

分子蒸馏是一种高效的生物油分离技术。本文应用刮膜式分子蒸馏装置,对模拟生物油在不同蒸馏温度、蒸馏压力和进料速率下的分离特性进行了研究,考察不同因素对族类化合物蒸出特性的影响。随后采用响应面分析法对模拟生物油分子蒸馏进行了计算机模拟,考察多种因素对分子蒸馏的交叉影响。通过ANOVA分析,模型的F值为21.25,表明模型是显著的。并以目标物酸醛酮在馏分中的质量分数为响应值得到最佳工况：蒸馏温度69.83℃,蒸馏压力1498.31Pa,进料速率5.54mL/min,此时轻质馏分中酸醛酮的质量分数为39.12%。最后在此工况下开展了模拟生物油的验证实验,结果显示馏分中目标物的质量分数为38.96%,与响应面模型吻合良好。模拟生物油经过分子蒸馏后酸醛酮的质量分数由28.50%提升至38.96%,同时酚类的质量分数由37.50%降低到25.14%。     

星点设计-响应面法优化黄芪多糖提取工艺实验研究

建立黄芪多糖最佳提取工艺.通过单因素试验与正交设计试验,应用Box-Behnken中心组合试验设计和响应面(RSM)分析法,以黄芪多糖得率为响应值,回归分析黄芪多糖提取的影响因素,优选黄芪多糖提取工艺.结果表明正交设计与响应面法优化结果接近,所得黄芪多糖的最佳提取条件为:提取时间40min,水提取温度100℃,液料比(...     

响应面法优化微波辅助水蒸气蒸馏法提取油樟精油工艺

为了解决油樟精油传统提取工艺时间长、效率低、耗能高和成本高等问题,本文遵循绿色提取理念,采用微波辅助水蒸气蒸馏法提取油樟精油并优化最佳提取工艺。根据单因素试验并结合响应面法建立二次回归模型进行方差分析和诊断,考察物料粒度、微波提取时间和微波提取功率对油樟精油得率的影响,确定最佳提取工艺并对理论结果进行实验验证。结果表明,在油樟精油得率相似的情况下,与传统的水蒸气蒸馏法（2h）相比,微波辅助水蒸气蒸馏法（10min）具有提取时间更短、效率更高和更节约能源的优势。通过二次多项式回归模型极显著（P<0.01）,失拟项不显著（P>0.05）,决定系数为R²=0.989等分析结合诊断图表明该模型对数据拟合良好。微波辅助水蒸气蒸馏法提取油樟精油最佳提取工艺为：物料粒度10目,微波提取时间11min,微波提取功率630W,此条件下油樟精油得率为4.479%,与实验验证结果（4.442%±0.16%）基本一致,验证了二次回归模型的可靠性。该技术较传统工艺提取时间短、效率高、耗能少、成本低,更加绿色安全且容易实现产业化,有望提高油樟精油在日化、美容、医药等各个领域的应用价值。     

响应面法优化海藻酸钠固定α-淀粉酶的研究

利用海藻酸钠为载体包埋制备固定化α-淀粉酶,在海藻酸钠浓度,氯化钙浓度和游离酶添加量的单因素实验基础上,采用响应曲面设计对三因素进行优化确定固定化的最优条件。得到的最佳条件为:海藻酸钠浓度为2.48%、氯化钙浓度为2.04%、游离酶浓度为0.23%,在该条件下进行验证实验得到固定化酶的回收率为74%,达到了较高的固定化酶的回收率。     

响应面法优化光电-Fenton氧化处理印染废水

以TiO_2/Ti为阳极,活性炭纤维(ACF)为阴极,Fe板为感应电极,在紫外光的照射下构建光电-Fenton(PEF)装置,并采用响应面法(RSM)考察其处理实际印染废水的脱色能力。结果表明,各因素显著性顺序为:初始pH反应时间电流密度曝气速率,数学模型回归性较好;在初始pH=4.52,反应时间为130.37 min,电流密度为7.47mA/cm~2,曝气速率为1 579.96 mL/min时,模型预测的脱色率为98.51%,与实际值仅有1.06%的误差。     

星点设计-响应面法优化芦荟多糖提取工艺

文章采用了星点设计-响应面法优化了芦荟多糖的提取工艺。选取提取温度、提取时间、液料比为自变量,多糖得率作为因变量。优化出最佳提取工艺条件为:提取温度为39.22℃,提取时间为3.05 h,液固比为29.62 m L/g,在此优化条件下,多糖得率为9.704%。该方法优化芦荟多糖提取工艺具有简单、预测性好等特点。     

响应面法优化一水硫酸氢钠流化催化精馏生产乙酸乙酯工艺条件

以新型的一水硫酸氢钠为催化剂,采用粉末状催化剂混合乙酸一起进料的加入方式,即流化催化精馏工艺,并利用响应面法优化乙酸乙酯催化精馏过程条件.首先,通过单因素灵敏度分析法对乙酸进料量、酸醇进料摩尔比、回流比、催化剂用量、釜底加热功率5个因素进行实验考察,确定了乙酸进料量、酸醇摩尔进料比、回流比3个关键因素的优化值及取值范围.根据单因素实验结果与精馏塔设备要求,塔釜加热功率和催化剂用量分别设定为68 W和2.0%(质量分数)乙酸,采用中心组合设计原则对乙酸进料量、酸醇进料摩尔比和回流比3个关键因素进行实验设计.以乙醇转化率为响应值,基于响应实验结果,利用响应面法对实验结果进行了方程回归,得到3个关键因素与响应值的二次关联模型.通过方差分析和平行实验,证明该模型准确可用.优化后的乙酸乙酯流态化催化精馏工艺条件为乙酸进料量3.2 mol·h^-1,酸醇进料摩尔比为3.1,回流比为3.3,在此优化条件下进行实验,乙醇转化率为88.67%,比基于单因素灵敏度分析法得到的优化工艺条件下乙醇转化率高1.0%.     

Application of response surface methodology for modeling and optimization of membrane distillation desalination process

In this work, response surface methodology (RSM) was applied for modeling and optimization of operating parameters for water desalination by direct contact membrane distillation (DCMD) process using polypropylene membrane (PP) with low pore size. Operating parameters including vapor pressure difference, feed flow rate, permeate flow rate and feed ionic strength were selected and the optimum parameters were determined for DCMD permeate flux. The developed model for permeate flux response was statistically validated by analysis of variance (ANOVA) which showed a high value coefficient of determination value (R² = 0.989). The obtained optimum operating parameters were found to be 0.355 × 10⁵ Pa of vapor pressure difference, feed flow rate of 73.6 L/h, and permeate flow rate of 17.1 L/h and feed ionic strength of 309 mM. Under these conditions, the permeate flux was 4.191 L/(m² h). Compared to a predicted value, the deviation was 3.9%, which confirms the validity of the model for the DCMD process desalination optimization. In terms of product water quality, the DCMD process using hydrophobic PP membrane can produce high quality of water with low electrical conductivity for all experimental runs.     

基于响应面法的折流板除雾器分离性能优化

用响应面分析法分析不同排液结构对新式异型折流板除雾器气液分离性能的影响,并对排液结构参数进行优化设计. 通过单因素实验对比筛选对除雾器性能具有显著影响的关键参数,用中心复合设计实验建立响应面多元回归模型,分析影响除雾器性能系数的参数间交互作用,得出最优参数. 结果表明,影响除雾器性能参数的最优取值为分离气速2.6 m/s、排液钩高度7.3 mm、前置排液槽和后置排液槽宽度分别为3.1和2.3 mm. 优化的折流板除雾器性能系数计算值为2.073,实验值为1.875,优化结果较可靠.     

中空纤维空气隙式膜蒸馏海水淡化过程的性能模拟与优化

利用响应曲面法(RSM),以模拟标准海水(质量分数3.5%)为进水对中空纤维空气隙式膜蒸馏(AGMD-HF)海水淡化过程的影响因子和膜通量指标进行了模拟优化。通过面向中心复合设计法(CCD)实现了基于热料液进水温度、冷凝液进水温度和料液流量的实验优化设计,并建立了响应值与影响因子之间的二次多项式回归模型。方差分析(ANOVA)、RSM分析及实验响应值与预测值的对比验证了该模型对影响因子和膜通量模拟优化的可信度。进一步地,通过期望函数的引入确定了各影响因子最佳水平,并利用太阳能加热驱动过程实验进行验证。结果表明,ANOVA的决定系数R²达到0.986,p值则低于0.0001;实验膜通量与预测值平均误差仅为6.95%,产水电导率始终保持在10 μS·cm^-1以下,脱盐率稳定在99.99%以上;最佳影响因子水平分别为83.5℃、13.2℃和60.2 L·h^-1,在此条件下太阳能加热驱动过程膜通量达到6.47 L·m^-2·h^-1。该实验不仅为潜在可行的规模放大过程提供了可参照的操作参数,而且表明将太阳能引入AGMD-HF海水淡化过程具有很强的实际应用潜力。     

Response surface methodology applied to optimization of distilled monoglycerides production

This work demonstrates that response surface methodology (RSM) is a powerful tool for the optimization of the production of distilled MG. Experiments with a centrifugal molecular distillator having an evaporation area of 0.0046 m² were carried out using RMS to identify operating conditions that can lead to higher MG purity. The independent variables studied were the evaporator temperature (TEV) and the volumetric feed flow rate (Q). The experimental range was from 100 to 300°C for TEV and between 5 and 15 mL/min for Q. High-performance size exclusion chromatography was used to evaluate TG, DG, MG, FFA, and glycerol (GL) compositions. Results were presented as MG concentration surfaces. Starting from a material with 10.8% of TG, 37.7% of DG, 43.6% of MG, and 7.2% of GL, the maximum MG, purity in the distillate stream with just one distillation step was 82.6% at a TEV equal to 250°C and Q equal to 5 mL/min. At these conditions, the MG recovery was 61%. A strategy was developed to obtain distilled MG with 96.3% purity.     

基于响应曲面法的三相泡沫灭火剂基础配方优化设计

为得到发泡及稳定性能优异的三相泡沫,响应曲面法优化设计三相泡沫灭火剂基础配方。通过单因素实验确定表面活性剂及固相粉体为SDS、Fc-134、6501、2000目（6.91 μm）合成云母粉,以发泡高度及稳定时间为响应值,研究其交互作用。利用Box-Behnken方法,建立的二次回归模型显著可靠,该模型预测SDS、Fc-134、6501浓度分别为2.64%,0.096%,3%,合成云母添加量为10 g时,为最优组合,预测发泡高度1533.86 ml,稳定时间12.8792 min,实验得到发泡高度为1550 ml,稳定时间为12 min,误差分别为1.05%,6.82%。与未优化三相泡沫比较在发泡高度及稳定时间分别提高14.8%、26.3%。结果表明,经优化设计三相泡沫发泡及稳定性能较未优化三相泡沫有明显提高且响应曲面法建立的预测模型误差较小,因此,该模型可用于提升三相泡沫灭火剂的发泡及稳定性能,为三相泡沫灭火剂配方设计提供参考。     

基于响应曲面法的反应-萃取-结晶工艺优化

氯化钙与二氧化碳通过反应-萃取-结晶工艺制备碳酸钙和氯化氢气体是制碱废液资源化利用的有效途径。用响应曲面中的Box-Behnken Design(BBD)设计实验,考察了氯化钙浓度、萃取剂体积分数、相比和温度4 个因素对反应-萃取-结晶耦合工艺中氯化钙转化率、有机相中氯化氢浓度以及产物碳酸钙的平均粒度的影响及交互作用,并分别建立了三响应值与影响因素间的回归方程。三响应预测最佳值分别为:氯化钙转化率95.08%、有机相氯化氢浓度1.126 mol·L^-1、碳酸钙平均粒度48.71 μm;相应的实验值分别为92.35%、1.123 mol·L^-1 和49.14μm。预测值与实验值接近,误差较小,说明建立的模型对于反应-萃取-结晶工艺的分析和预测准确可靠。     

Research on optimum heating system design for rapid thermal response mold with electric heating based on response surface methodology and particle swarm optimization

A new electric‐heating rapid thermal response (RTR) mold with floating cavity/core for rapid heat cycle molding is investigated in this study. Process principles of Rapid heat cycle molding (RHCM) with such new electric‐heating mold are discussed and presented. Response surface methodology (RSM) is employed to develop mathematical relationships between layout of the heating elements and heating efficiency, temperature uniformity and structural strength of the floating cavity. Three explanatory variables including half distance between two adjacent heating rods, spacing between heating rods and cavity surface, and the diameter of the heating rod are used to describe the layout and scale of the heating elements. The response variables involving required heating time, maximum cavity surface temperature, and maximum von‐Mises stress are used to characterize heating efficiency, temperature uniformity, and structural strength of the floating cavity, respectively. Central composite design (CCD) method is used for factorial experiments. Finite element analyses are conducted for combination of explanatory parameters to acquire the corresponding values of the response variables. Three predictive models for the response variables are created by regression analysis. Analysis of variance (ANOVA) is used to check their accuracy. These response surface models are interfaced with an effective particle swarm algorithm for the optimum heating system design of the electric‐heating RTR mold. The developed optimum method is then used for the design of the floating electric‐heating cavity for an actual industrial product. The following heat transfer analysis results show that the temperature distribution uniformity of the cavity surface is greatly improved with the optimal cavity structure and layout of heating rods. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Fermentation optimization for the production of lovastatin by Aspergillus terreus: use of response surface methodology

A Box–Behnken experimental design was used to investigate the effects of five factors—ie oxygen content in the gas phase; concentrations of C, N and P; and fermentation time—on the concentrations of biomass and lovastatin produced in batch cultures of Aspergillus terreus. The values of the various factors in the experiment ranged widely, as follows: 20–80% (v/v) oxygen in the aeration gas; 8–48 g dm^?3 C‐concentration; 0.2–0.6 g dm^?3 N‐concentration; 0.5–2.5 g dm^?3 phosphate‐concentration; and 7–11 days fermentation time. No previous work has used statistical analysis in documenting the interactions between oxygen supply and nutrient concentrations in lovastatin production. The Box–Behnken design identified the oxygen content in the gas phase as the principal factor influencing the production of lovastatin. Both a limitation and excess of oxygen reduced lovastatin titers. A medium containing 48 g dm^?3 C supplied as lactose, 0.46 g dm^?3 N supplied as soybean meal, and 0.79 g dm^?3 phosphate supplied as KH₂PO₄, was shown to support high titers (～230 mg dm^?3) of lovastatin in a 7‐day fermentation in oxygen‐rich conditions (80% v/v oxygen in the aeration gas). Under these conditions, the culture medium had excess carbon but limiting amounts of nitrogen. The optimized fermentation conditions raised the lovastatin titer by four‐fold compared with the worst‐case scenario within the range of factors investigated. Copyright © 2004 Society of Chemical Industry