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。     

矿井主通风机变频调速节能技术的应用

为了研究通风机变频调速技术节能效果,分析了变频节能原理:当通风机排风量减小时,转速降低,通风机的轴功率按转速的三次方降低,从而达到变频调速节能目的。设计了通风机变频系统方案,分析得到了该方案通风机最佳工矿点转速为500 r/min,效率提高了24%。分别分析节电量、节电率、经济效益和环保效益对采用变频调速技术进行节能的验证效果,显示节能效果明显。     

变频技术在矿用通风机上的应用研究

根据实际工作经验和相关文献的研究,阐述了变频技术在目前煤矿生产行业的应用现状,提出了目前矿用通风机在节能方面存在的主流问题,并总结了通风机变频控制技术的优点。基于某煤矿开采的通风机变频控制系统,对通风机变频技术做简要介绍;对变频控制原理、变频调速控制系统总体设计进行说明。以期该技术总结可为通风机变频技术的应用提供参考。     

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。     

矿用变频远程控制局部通风机的应用分析

针对传统矿用局部通风机节能效率差、无法自动变频等技术难题,对原掘进工作面传统FBD型局部通风机进行优化,采用了一套变频远程控制局部通风机,并对其结构、工作原理进行分析。优化后的变频远程控制局部通风机节能效果好,实现了远程控制,提高了通风调节自动化水平。     

变频调速技术及其在矿用对旋轴流式通风机上的应用

在分析变频调速技术原理的基础上,以某矿井为实现节能减排的目的而选用的型号为FBCDZ-6-№18的对旋轴流式通风机为例,具体分析在旋轴流式通风机上运用变频调速技术所产生的节能效果。对通风机实测的变频数据显示:为该通风机配备2×110 k W、380 V的电动机后,Ⅰ级、Ⅱ级叶轮的变化有明显的差异,节能的幅度在12%~51%左右。     

变频器在煤矿通风机中的应用研究

分析了变频器对通风机具有稳定电流、扩大调速范围、辅助风机节能的作用,对变频器在煤矿通风机中的应用包括变频器设备选择、系统设计、控制方式进行详细分析。分析认为,变频器在煤矿通风中的应用,有效保障通风机电机的安全运行,可促进通风机的节能减耗。     

变频调速在降低通风机能耗中的应用

简要分析了通风机的调速节能原理,探讨了传统的风机调节方法和变频调节方法的差异以及变频调节技术在风机调速的实践应用。证实变频调速技术对降低矿井通风机能耗具有重要意义。     

通风机应用稀土永磁同步电动村的节能研究和技术分析

通过对通风机同时使用稀土永磁同步电动机和Y系列电动机实际对比运转试验,揭示了试验中稀土永磁同步电动机应用于通风机还存在的问题,并就通风机使用稀土永磁同步电动机和Y系列电动机进行了针对性的对比节能分析和计算,指出了稀土永磁同步电动机不仅在通风机而且在其他一切使用场合的节能经济效益和社会效益都是巨大的。     

新型变频局部通风机的研制

针对目前煤矿变频通风机存在的问题,研制了一种新型的集变频和通风机于一体的BBKJ2×30型变频局部通风机,通过对其设计结构组成、原理、特点、适用条件进行分析,进一步对变频局部通风机进行试验运行,实验证明,该通风机能给矿井通风带来巨大的节能效果。     

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.     

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.     

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....     

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.