某食品加工企业腌泡池智能清洗车设计的方案探讨

针对某食品加工企业上百个大型腌泡池的经常性清洗任务需求,基于现代机电控制技术,提出智能清洗车的解决方案,重点探讨这种清洗车的型式及结构、液压系统与电气控制部分的设计.     

基于 MPDE-EEMD 及自适应共振解调的轴承故障特征提取方法

针对滚动轴承振动信号具有非线性、非平稳性和非高斯性,并且故障特征往往淹没于系统噪声之中而难于识别的问题, 提出了以多种群差分进化(multiple population differential evolution, MPDE) 算法来改进集合经验模式分解( ensemble empirical mode decomposition, EEMD) 的 MPDE-EEMD 消噪方法,并与自适应共振解调技术( adaptive resonance demodulation technique, ARDT)相结合实现故障特征提取。 首先,为了解决 EEMD 中加入参数依靠人工选择且难以准确获取的问题,建立极值点分布 特性评价函数,利用 MPDE 来寻优获取最佳白噪声幅值,实现 EEMD 自适应分解。 然后,采用峭度与相关性相结合的准则对分 解后的 IMF 分量进行自动筛选,将满足条件的有效信号进行重构,实现对原始振动信号的降噪处理。 最后,采用 ARDT 自动确 定对消噪信号进行带通滤波的带宽和中心频率,再通过包络解调提取出滤波信号的特征频率。 将轴承仿真故障信号与实际故 障信号用于算法的验证,结果表明 MPDE-EEMD+ARDT 能有效提取出轴承故障特征。     

ADB610钢焊接接头概率疲劳裂纹扩展分析

采用焊条电弧焊方法对ADB610钢进行焊接,对焊接接头进行疲劳裂纹扩展试验,研究其概率疲劳裂纹扩展规律.采用两步七点递增多项式拟合方法,计算了一系列相同裂纹长度下母材区、热影响区和焊缝区的对数裂纹扩展速率方差和存活率分别为50%,90%,95%,99%,99.9%的裂纹扩展速率.结果表明,总体上母材区的裂纹扩展分散性最小,热影响区其次,焊缝区分散性最大;而且总体上存活率相同时,在裂纹扩展的初期,母材区的裂纹扩展速率最快,焊缝区的裂纹扩展速率最慢;在裂纹扩展末期,三区域的裂纹扩展快慢相当;随着存活率增大,三区域裂纹扩展快慢差别不大时所对应的裂纹长度减小.     

ADB610D钢焊接接头冲击吸收功的统计分布模型

通过进行ADB610D钢焊接接头的冲击吸收功Akv的测定试验及数据采集,建立了确定冲击吸收功的统计分布模型,经多种数理统计检验,对Akv的统计分布函数进行了拟合检验。结果表明：威布尔二参数分布函数是描述ADB610D钢焊接接头冲击吸收功Akv的最佳拟合分布函数。     

A new approach for forecasting OPEC petroleum consumption based on neural network train by using flower pollination algorithm

Petroleum is the live wire of modern technology and its operations, with economic development being positively linked to petroleum consumption. Many meta-heuristic algorithms have been proposed in literature for the optimization of Neural Network (NN) to build a forecasting model. In this paper, as an alternative to previous methods, we propose a new flower pollination algorithm with remarkable balance between consistency and exploration for NN training to build a model for the forecasting of petroleum consumption by the Organization of the Petroleum Exporting Countries (OPEC). The proposed approach is compared with established meta-heuristic algorithms. The results show that the new proposed method outperforms existing algorithms by advancing OPEC petroleum consumption forecast accuracy and convergence speed. Our proposed method has the potential to be used as an important tool in forecasting OPEC petroleum consumption to be used by OPEC authorities and other global oil-related organizations. This will facilitate proper monitoring and control of OPEC petroleum consumption.     

直接接触沸腾换热过程连续相特征提取及分布规律

利用支持向量机(SVM)理论构建了有机工质?导热油直接接触沸腾换热过程连续相特征提取方法,获得了导热油和气泡群两相流流型的拓扑结构。对9组正交实验工况获得的两相流图像分别进行连续相特征提取和同调群计算,得到量化连续相数量的1维和0维贝蒂数?1和?0用于粗略估计气泡群数量,并与传统数字图像处理方法的结果比较,对比了换热效率较好和较差情况下形态学开运算对SVM方法的影响,建立了两相流贝蒂数演化规律与换热效率的关联性,比较了传统方法获得的气泡群数量和SVM方法获得的连续相“洞”的数量的演化规律。结果表明,SVM结合贝蒂数方法不仅可准确量化导热油连续相,且可粗略地表征气泡分散相;L6工况(连续相导热油液位高度Z=0.5 m、初始换热温差?T=120℃、分散相工质流率U0=0.04 m/s、连续相导热油流率Uc=0.15 kg/s)下连续相数量变化几乎重叠,相对波动较小,而L4工况(Z=0.5 m, ?T=80℃, U0=0.06 m/s, Uc=0.3 kg/s)下连续相数量偏离程度较大;SVM方法获得的连续相和气泡群个数演化曲线同步,且混合时间相同,?1和?0中位数偏离程度的局部最小值可作为性能指标之一,通过实验验证可优选出换热效果最好的工况。     

A novel method for measuring spatial uniformity of irregular boiling bubbles in a direct contact heat exchanger

As the binary image fails to reflect the density distribution of the bubble, this paper proposes an improved new indicator for accurate measurement of spatial uniformity based on gray image analysis: moment. Compared with the inclination angle method in binary image, the test results show that the two methods have significant positive correlation. The experimental results also indicate that the evolution curve of bubble numbers is consistent with its moment evolution curve, and the moment evolution fitting curve can distinguish the high noise in the experiment. Compared with other methods, mixing performance index (t) obtained by moment evolution fitting curve is correlated with heat transfer performance (Pearson correlation coefficient a = −0.94). The variation in characteristic area of the bubble in the direction of bubble growth can characterize the heat transfer performance. The index of dispersion of the global moment and the local moment indicates that the local moment can be used to precisely quantify the spatial uniformity of boiling bubbles. This work could also be applied to study a variety of problems involving spatial uniformity through visualization techniques.     

不同焊接方法对B610CF钢焊接接头性能的影响

采用焊条手工电弧焊和富氩混合气体保护焊两种焊接方法对低焊接裂纹敏感性钢B610CF钢板状对接接头分别进行了三种焊接规范下的焊接,并对其焊接接头进行了金相分析和力学性能试验研究.结果表明,采用焊条手工电弧焊的焊接接头抗拉强度和焊缝的冲击韧性优于采用富氩混合气体保护焊的,两种焊接方法下的焊缝区的冲击韧性值都低于母材的;两种方法的热影响区金相组织和冲击韧性没有明显的差异.不同焊接方法下焊缝性能的差异以及与母材基体的差异,与所选用的焊接材料的性能有关,尽量选用与母材的强度和冲击韧性相匹配的焊接材料,以提高整个焊接接头的性能.     

35CrMoV钢硬度概率分布与抗拉强度设计许用值预测分析

采用最小二乘法和K-S检验方法进行分布拟合检验,在求得35CrMoV钢硬度和抗拉强度正态分布的基础上,对其硬度和抗拉强度关系进行相关性研究,运用线性相关系数判断硬度和抗拉强度之间具有强正线性相关关系.运用正态代数运算方法,从硬度的概率分布估计抗拉强度的概率分布,预测其设计许用值,并与从抗拉强度概率分布计算得到的设计许用...     

层次分析法在呼吸监护仪创新设计中的应用研究

层次分析法是一种定性和定量相结合的、系统的、层次化的评价方法.在呼吸监护仪创新设计开发过程中,采用了层次分析法对其外观造型进行设计评价.先制定呼吸监护仪外观造型的评价准则,并确定其需要满足的要求,建立呼吸监护仪外观造型层次分析法评价的递阶层次结构,采用定性和定量相结合的方法判断出整体最优的设计方案.通过层次分析法的应用...