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油田稠油热采注汽锅炉的除氧系统先后经历了热力除氧、海绵铁除氧、真空膜式除氧、真空除氧等发展阶段,其中热力除氧和海绵铁除氧由于达不到节能环保要求逐渐被替换为真空除氧,本文介绍了真空除氧器在实际应用中的探索和尝试。 相似文献
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本文介绍了工业锅炉除氧的必要性、除氧的现状、除氧的方法及其原理;并阐述了除氧设备的计算机控制系统,及DKNK多功能控制器的功能和特点。 相似文献
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结构新颖的低位集成真空除氧设备 总被引:1,自引:0,他引:1
结构新颖的低位集成真空除氧设备黑龙江省机械制造学校赵志宽贺东伟锅炉给水中的氧对锅炉各主要部件及管道均有严重腐蚀,影响了锅炉的安全运行,为此国家标准规定凡蒸发量在2t/h以上的锅炉必须除氧。目前锅炉除氧的方法有热力除氧,普通真空除氧、解析除氧、化学除氧... 相似文献
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简述了氧传感器的功能,构造、工作原理及其类型,分析了氧传感器的故障原因,指出了氧传感器的故障诊断与维修方法。 相似文献
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固相微萃取和气相色谱-质谱法测定北京酱牛肉中的挥发性成分 总被引:3,自引:0,他引:3
采用顶空固相微萃取和气相色谱-质谱法(Head Space Solid Phase Microextraction Gas Chromatgraphy-Mass Spectrometry,HSSPME—GC—MS)对北京传统酱牛肉中的挥发性香气物质进行了测定,总共检测出68种风味化合物,其中包括醛类49.12%、酮类0.84%、醇类4.85%、烃类13.29%、酯类2.61%、酚醚类11.33%和含硫含氮及杂环化合物6.55%,另外还有11.41%的其它类物质,其中醛、酮和含硫含氮及杂环化合物中含有北京传统酱牛肉的主要香味成分。 相似文献
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螺旋锥齿轮珩磨轮的制造方法 总被引:1,自引:0,他引:1
对用于螺旋锥齿轮珩磨加工的珩磨轮模具制造的关键技术进行深入研究。介绍珩磨轮齿面准均布网格点的计算方法,通过计算这些准均布网格点及其径矢和法矢,建立齿面上每一个网格点的拨模极限导程的数学模型。通过计算齿面上这些网格点的可行的螺旋线导程,判断其交集是否为空集,并以此作为判断是否出现拨模干涉的依据。针对已经出现的拨模干涉,提出拨模导程的优化方法以及干涉的修正方案和齿面光顺过程。详细讨论金属模具的逐点成形和展成加工方法以及它们各自的适用范围和可加工性,并以刀倾法为例,阐述加工螺旋锥齿轮珩磨轮的金属凸模的计算步骤,为螺旋锥齿轮珩磨轮的制造提供理论依据。 相似文献
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Anthony N. Kounadis 《International Journal of Mechanical Sciences》1998,40(10):1672
A qualitative dynamic buckling analysis of imperfection-sensitive non-conservative dissipative systems under path-dependent loading in regions of divergence is presented. Despite the lack of potential for this type of loading a total energy-balance equation allows us to establish a sufficient criterion for dynamic buckling, the counterpart of that valid for potential systems. Moreover, using energy and geometrical considerations for the channel of motion, one can obtain for a 2-DOF model dynamic buckling loads (DBLs) which are practically exact for vanishing but non-zero damping and very accurate for non-zero damping. Numerical results show the efficiency and reliability of the proposed qualitative analysis. 相似文献
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In this paper the theoretical and experimental aspects are described concerning the validation of a method for the measurement of the percentage composition of a generic liquid fuel, even though specific reference materials for instrumentation calibration are unavailable. This new method could be used for the evaluation of the Emission Factor (EF) of an unknown fuel for emission trading purposes, according to the requirements of both the juridical and technical standards. The validation of the procedure is based on the comparison of different techniques for the measurement of Gross Calorific Value (GCV), Net Calorific Value (NCV) which are quantities useful in EF evaluation; this new combination of actions established a complete and validated methodology for EF evaluation. The experimental results and uncertainty analysis show that this method is suitable for the estimation of the composition measurement and also that of GCV, NCV and EF also for non-standard liquid fuels; a comparable accuracy with respect to the methods for standard fuels has been estimated, making this method suitable for practical applications. 相似文献
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BranchSampler is a system for computer-assisted manual stereology written for handheld devices running Windows CE. The system has been designed specifically to streamline data collection and optimize sampling of tree-like branching structures, with particular aims of reducing user errors, saving time, and saving data in formats suited for further analysis in other software, for example, a spreadsheet. The system can be applied in a wide range of applications, from biomedical science to agriculture and horticulture. It can be applied for sampling nested generations of lung bronchioles and renal arterioles or for collection and optimizing sampling of crops for precision agriculture. Although the system has been designed specifically for sampling branching structures, it is sufficiently flexible to be used for other applications involving nested stereological designs. We describe the system specifications, software and Graphical User Interface development, functionality and application of the handheld system using four examples: (a) sampling monkey lung bronchioles for estimation of diameter and wall thickness (b) sampling rat kidney for estimating number of arteries and arterioles in a specific generation (c) mapping fruit (apple) tree yield in an orchard and (d) estimating the total leaf surface area of chrysanthemum plants in a greenhouse. 相似文献
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Peter MartinSteven J. Rothberg 《Mechanical Systems and Signal Processing》2011,25(7):2753-2765
Pseudo-vibration sensitivities in laser vibrometry are the consequence of measurement noise generated by surface motions other than that on-axis with the incident laser beam(s), such as transverse and tilt vibrations or rotation. Concentrating solely on commercial laser vibrometers to maximise value to the vibrometer user, this paper quantifies pseudo-vibration sensitivities for five single beam instruments (for translational vibration measurement) and two parallel beam instruments (for angular vibration measurement) across a range of surface treatments and roughnesses. Transverse, tilt and rotation sensitivities are quantified for the single beam instruments. In-plane rotation, rotation and tilt sensitivities are quantified for the parallel beam instruments. Estimates of sensitivities for parallel beam instruments based on related quantifications for single beam instruments are shown to offer order-of-magnitude agreement. Further confirmation is provided of the benefits of smaller laser beams for measurements on tilting or rotating surfaces and of larger beams for measurements on surfaces with transverse motion. For rotor vibration applications, lower sensitivities are found for a focus location on the shaft rotation axis rather than its surface. Based on experimental evidence, refinements to the test methods are suggested with a view towards the formation of a Standard. These comprise placing limits on surface flatness and rotor out-of-roundness, inclusion of agreed ranges for target displacement amplitude and rotor diameter, and acknowledgement of the importance of focus location for rotation sensitivities. 相似文献
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D. H. Park S. S. Kang S. B. Park 《The International Journal of Advanced Manufacturing Technology》2002,20(1):31-38
In this paper a surface area calculation for non-axisymmetric deep drawing products of elliptical shape was constructed for
the design of blank shapes of deep drawing products by using an AutoLISP function in AutoCAD software. A computer-aided process
planning (CAPP) system for rotationally symmetric deep drawing products has been developed. In this study, a CAPP system for
non-axisymmetric deep drawing products of elliptical shape was constructed using process sequence design. The system developed
consists of four modules. The first is the recognition of shape module for recognising non-axisymmetric products. The second
is a 3D modelling module for calculating the surface area for non-axisymmetric products. The third is a blank design module
for creating an oval-shaped blank with an identical surface area. The fourth is a process planning module based on production
rules that play the most important role in an expert system for manufacturing. The production rules are generated and upgraded
by interviewing field engineers. The drawing coefficient, the punch and die radii for elliptical shape products are considered
as the main design parameters. The suitability of this system was verified by applying it to a real deep drawing product.
This surface area calculation and CAPP system should be very useful for reducing the lead-time for manufacturing and for improving
the accuracy of products. 相似文献
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针对当前工业物联网系统中存在的异构性和互操作性问题,本文介绍了一种工业物联网技术及标准体系,该标准体系中包括了工业物联网身份标识、工业物联网应用属性协议、工业物联网服务协议以及工业物联网互操作协议四项标准。该系列标准的制定将有利于提高工业物联网的运行效率和互操作性,为工业物联网发展提供支持。 相似文献
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针对目前国内在发动机凸轮检测中 ,选择检测基准、确定检测位置、测头切换、最小判别等方面存在的带有普遍性的影响凸轮检测准确性的问题进行了分析 ,并参照 GB/T1 1 82 -1 996和 GB/T1 6671 - 1 996,以“最小条件”为依据 ,从发动机凸轮升程和转角是非线性函数关系入手 ,对选择凸轮检测基准原则、确定凸轮检测位置 (求解检测起始转角 )方法、凸轮升程检测数据的处理、凸轮升程合格性的判定等进行了论述 相似文献