通风机变频节能监控系统的设计及节能分析

为解决通风机当前控制系统无法根据工况或实际需风量对通风机风量、风速等参数进行调节且容易在启动阶段对设备和电网造成冲击的问题,在对通风机结构简单阐述的技术上,提出了通风机变频调速监控系统的总体设计思路,重点对变频调速功能实现的硬件进行选型设计,对变频调速技术的应用效果进行全面评估。     

矿井通风机中压变频器调速系统设计及应用

针对矿井通风机工作负荷特点,分析了矿井通风机变频调速节能原理,阐述了应用于矿井通风机的中压变频器应具有的功能特点,设计矿井通风机中压变频调速控制方案。实践证明,该方案可以改善风机工作性能,实现节能降耗和提高效率的目的。     

变频调速在大功率通风机中的应用

针对传统风机在调速设计上存在的效率较低且能耗较大的问题,提出了基于PLC控制变频调速的技术设计方案,利用计算公式得知：当通风机风量缩减时,转速同步缩减,同时风机功率将以转速的三次方比值降低。利用该调速设计,得出了通风机运行最佳转速,通风效率大幅提升,节能效果显著。     

矿井主通风机的变频调速和节能降耗

为了满足矿井主通风机在不同生产阶段风量变化的要求,论文详细叙述了主通风机风量调节方式,系统地介绍了目前常用变频器类型与原理及常用两种调速方式,从理论上分析了转速与功耗的关系,确定了矿用变频器的形式,通过变频调速,使风机达到高效节能的目的。     

矿用轴流式风机节能途径探讨＊

通过对通风机经济运行理论及节能方法的分析研究,提出了矿井轴流式主要通风机高效经济运行的方法措施：合理选择通风机;运行中采用改变叶片安装角度和变速等调节法;采用改变叶片安装角度和变速综合调节法;采用变频调速技术,合理选用变频电机或原电动机加装变频器等。     

矿井主通风机上变频调速节能技术的应用

针对主通风机存在严重的功率浪费的现象,在分析变频节能技术原理的基础上,提出了矿井主通风机上变频调速节能技术。该技术在主通风机上的应用,可节省电量25%,预计可延长风机工作寿命约30%,提升了主通风机的工作效率,降低其耗电量与经济成本。     

矿用通风机变频控制系统设计与研究

目前煤矿通风机的控制方式多采用恒转速控制,无法根据实际需求对风机功率及输出风量进行实时调节,造成较大的电能损耗,不利于煤矿经济性及智能化发展。基于此,结合变频控制及传感器技术设计一套基于PLC的矿用通风机变频节能控制系统,实现了风机软启动及输出风量自适应调节,同时系统可对风机的风压、风量等运行参数进行实时监测,有效提高煤矿通风机的智能化运行水平。     

煤矿主通风机变频节能技术的研究

为了研究煤矿主通风机变频节能的问题,以同煤集团四老沟矿为研究背景,通过对主通风机变频节能技术进行构想设计,分析变频节能技术的原理,并对变频器的特点进行比较,从而得出通风机节能减耗时的最佳转速。研究结果表明:通过对通风机安装变频节能装置,风机的调节系统灵敏,可以有效地切换风机的速率,减少了电能的损耗,延长了设备的使用寿命,从而间接地降低了矿井企业的生产成本,为同类型的矿井生产提供参考。     

煤矿通风机变频调速技术的研究与应用

针对传统的通风机调速存在的低效高损耗问题,设计了PLC控制变频调速技术方案,通过PLC实现制动化控制变频器,然后实现调节通风机的通风量.通过数学计算和实际成产中验证表明:当通风机风量降低时,转速变小,通风机的轴功率呈三次方降低,PLC控制变频调速系统方案,分析得到最佳转速,通风效率得到了大幅提升,节能效果、经济效益效果...     

变频调速技术在热电厂风机上的应用

提出了热电厂用风机采用变速调节的可行性和必要性。介绍了变频调速技术的优点,指出变频调速技术在低压（３８０Ｖ）小容量（２５０ｋＷ 以下）电机上较为成熟。通过一个实例的经济分析得出结论,热电厂锅炉（６５ｔ／ｈ 以下）配套风机使用变频调速技术较为理想。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

ANGULAR DISTORTION ALLOWABLE VALUE AND ASSESS METHOD OF WELD ON COKE TOWER

A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.