可燃气体报警器的选点安装与使用维护

可燃气体报警器由探测器与报警器构成,广泛应用于石油、天燃气、化工、油库等存在可燃气体的石油化工行业,用以检测室内外危险场所的泄漏情况,是保证生产和人身安全的重要仪器。当被测场所存在可燃气体时,探测器将气体浓度信号转换成电压信号或电流信号传送到报警     

可燃气体报警器的选点安装与使用维护

可燃气体报警器由探测器与报警仪构成 ,广泛应用于石油、燃气、化工、油库等存在可燃气体的石油化工行业 ,可检测室内外危险场所的泄漏情况。当被测场所存在可燃气体时 ,探测器将泄漏气体转换成电压信号或电流信号传送到报警仪表 ,仪器显示出可燃气体爆炸下限的百分比浓度值。当可燃气体浓度超过报警设定值时 ,该报警器发出声光报警信号提示值班人员及时采取安全措施 ,避免燃爆事故发生。下面将可燃气体报警器的选点、安装、使用及维护的方法和注意事项简单介绍一下。1　应用时的注意事项可燃气体报警器采用定点式安装 ,其位置不易更改。具…     

石油化工装置可燃气体报警器的类型及一般故障处理

可燃气体报警器广泛应用于石油、化工、加油站、油库、燃气站等场所,用以检测易燃、易爆气体的泄漏,通过及时报警功能来避免引起火灾、爆炸、中毒等重大事故的发生。该文简要介绍了可燃气体报警器的工作原理和常见类型,以及简单的故障维修处理手段,从而有利于促进安全生产,提高可燃气体报警器的使用效率。     

海上平台可燃气体报警器的故障处理及改进探讨

可燃气体报警器广泛应用于海上采油平台的井口、工艺甲板、修井机、变配电室等场所,用以检测易燃、易爆气体的泄漏,起到监测可燃气体浓度的作用,避免火灾、爆炸等重大安全事故的发生。该文简要介绍了海上采油平台可燃气体报警器的常见类型、工作原理、常见故障分析及处理,针对可燃气体报警器在海上采油平台的应用现状提出了相关改进建议,以提高其使用效率,确保海上平台的安全生产。     

KJB－1型可燃气体检测报警器的改进

ＫＪＢ－１型可燃气体检测报警器的改进锦西化工总厂杜虎山，王同庆北京燕山石化公司仪表厂生产的ＭＪＢ－１型可燃气体检测报警器是由Ｋ２－１型报警器（二次表）和Ｋ１－１型检测器）（一次表）组成。检测器安装在有可能泄漏出可燃气体的危险现场场所，报警器安装在控制...     

可燃气体报警器在化工生产装置中的具体应用分析

在化工生产过程中,通常会涉及对可燃危险气体的生产、使用,所以,危险气体泄漏报警系统的应用极为重要,化工企业必须正确安装可燃气体报警器,实现对可燃企业泄漏的及时报警,有效预防气体泄漏导致的中毒、火灾、窒息、爆炸等重大安全事故。本文对可燃气体报警器中的安装、校验、运行维护等问题以及具体措施等内容进行了深入分析、探讨,以提高化工生产装置的安全生产水平,保障生产运行维护人员的生命健康。     

可燃气体报警器的检定与正确使用

可燃气体报警器广泛应用于冶金、石油、化工、煤炭等行业和市政煤气、仓储、交通、宾馆饭店和消防部门,并逐步应用于家庭防火。它主要是测定环境空气中可燃气体的浓度,当空气中可燃气体浓度达到一定量时,报警器就会自动报警,进而做出排风或使截止阀动作反应,起到防止火灾和中毒事故发生的作用。《中华人民共和国计量法》和《中华人民共和国强制检定的工作计量器具管理办法》规定,可燃气体检测报警器属于强制检定计量器具,必须纳入依法强制管理范围,实施定点定周期强制检定。检定周期不超过一年。     

可燃及有毒气体报警器的应用

大连石化公司"84.1.1"事故发生后,各种类型的可燃、有毒气体检测报警器陆续安装到生产、储运装置上。近30年,从当年一催化10套可燃气体检测报警器发展到现在的2000多套,为安全生产提供了有力的保障,避免多起事故的发生。本文以在公司广泛使用的北京华德生产的气体检测报警器为例介绍其工作原理、安装及日常维护应用。     

可燃气体报警器计量检定及发展探析

可燃气体报警器随着社会对燃气的需求得到了广泛的应用,本文论述了可燃气体报警器计量检定工作的重要意义,阐述计量检定遵循的工作原则,并对检定工作内容给予较全面解析;根据新材料和新技术的发展,对可燃气体报警器及其计量检定的发展趋势作了两方面的探析。     

可燃气体报警器计量检定及发展探析

可燃气体报警器随着社会对燃气的需求得到了广泛的应用,本文论述了可燃气体报警器计量检定工作的重要意义,阐述计量检定遵循的工作原则,并对检定工作内容给予较全面解析;根据新材料和新技术的发展,对可燃气体报警器及其计量检定的发展趋势作了两方面的探析。     

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.     

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。     

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....     

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.     

Limits of topographic measurement by the scanning tunnelling and atomic force microscopes

Parameters describing the topographic character of a surface (height, surface wavelength, slope and curvature) can be derived from equivalent sinusoidal profiles. The response of a surface-measuring instrument may be modelled in terms of instrument parameters such as stylus radius, and scanning range and resolution. The performance of the instrument may then be mapped as a zone in amplitude-wavelength (AW) space to show the sinusoidal profiles it is capable of measuring. In a first-order analysis the STM and AFM are considered as equivalent to contact-stylus instruments with a notional stylus radius equal to the tip radius plus the gap. Comparisons between different instruments and types of instrument are readily made by mapping in AW space. The error arising from convolution of the sinusoidal profile with that of the finite tip may be quantified and plotted as contours in AW space.