共查询到20条相似文献,搜索用时 62 毫秒
1.
2.
介绍了长输管道泄压阀的结构及工作原理,分析了水击产生的原因,进行了水力瞬变分析编程计算,设计了泄压阀水力瞬变测试流程。通过试验验证泄压阀对管路水力状态的影响,为泄压阀控制水击提供了理论和试验依据。 相似文献
3.
涡轮增压系统在改善汽车动力性和燃油经济性的同时也带来了严重的噪声问题。为控制汽车涡轮增压系统泄压噪声,综合运用计算气动声学方法和动网格技术,分析泄压工况下泄压阀的准稳态响应和涡轮增压系统的瞬态响应,并结合宽带噪声源模型和声类比方法获取涡轮增压系统泄压噪声特性,揭示汽车涡轮增压器连续瞬变工况下泄压噪声的产生原因,明确泄压噪声强度与进气质量流量的关联。泄压噪声主要由壁面涡脱效应引起,呈现宽频特征,且声源强度随质量流量减小而降低。鉴于此,提出通过改进泄压阀结构进行进气质量流量控制进而实现泄压噪声控制,并对泄压阀结构进行改进设计。仿真分析结果表明改进后强声源区域明显减少,总声压级平均降低约24dB,泄压噪声得到有效控制。改进样件装车试验亦验证控制措施的有效性。该研究为涡轮增压系统泄压噪声分析与控制这一行业难题的解决提供有益参考。 相似文献
5.
泄压阀是高层建筑室内消防给水系统防止超压的有效措施。本文详细介绍了泄压阀的结构、工作原理、设计选用及安装应注意的事项。 相似文献
6.
7.
详细介绍了DANFLO水击泄压阀的结构和操作原理,以及长输管道发生水击的原因,并根据水击泄压阀在输油管道上的使用情况,提出在运行中的操作和维修建议。 相似文献
8.
9.
10.
详细介绍了中洛输油管道引进的新型水击泄压阀的结构和操作原理,并根据水击泄压阀在输油管道上的使用情况,提出使用和管理过程中的注意事项。 相似文献
11.
12.
R. Sarin A.K. Gupta D.K. Tuli A.S. Verma M.M. Rai A.K. Bhatnagar 《Tribology International》1993,26(6)
The ashless antiwear/EP additives based on phosphorodithioic acids are preferred to their heavy metal complexes, due to operational problems and enviromental restrictions being enforced in many countries. Four O, O-dialkylphosphorodithioic disulphides with varying alkyl chain length from C5 to C10 have been synthesized and their antiwear, EP and antioxidant performance examined vis-à-vis a commercial ZDDP in a mineral base oil. The synthesized products have been found to exhibit appreciable antiwear and antioxidant properties and mild EP performance, which are comparable to that of commercial ZDDP. 相似文献
13.
At winter-contaminated movement areas, the interfacial materials—snow and ice—cause the major operational problem related to aircraft performance. The central issue is how to evaluate the attainable friction force between the aircraft tyre(s) and the pavement and relate that to aircraft performance. In wintertime the operational window for aircraft movements can change rapidly and so a frequent reporting service of the surface conditions is warranted. Friction is both material and system dependent. An ongoing Joint Winter Runway Friction Measurement Program (JWRFMP) addresses this issue in an international effort to produce reliable data on friction at winter-contaminated movement areas in potentially slippery conditions. The traditional approach has been to measure the friction with tribometers to generate μ, the “friction number”. The substantial question is: what are these friction numbers? JWRFMP encourage a broad multidisciplinary approach to solve this question and to provide the international aviation industry with the best information attainable. The goal is to provide an International Runway Friction Index (IRFI) that comprises the relevant information to be used for the pilot/aircraft system. This IRFI should be based upon sound basic physics and an analytic approach to understanding and to solving the tribological problems involved. In this paper the interaction of aircraft wheel(s) on travelled winter surfaces of a movement area is outlined by a tribosystem and the operational envelope for the system is described. 相似文献
14.
15.
分析CYⅢ型液压操动机构系统的渗漏情况,对如何准确判断泄漏程度,如何根据温度变化调整微动开关,提高机构丁作质量提出建议。 相似文献
16.
17.
铁路起重机作业区域与起重性能一样是有效使用的基础,本文阐述了作业区域问题的由来,影响作业区域的诸因素,提出了作业区域图的创意,介绍了作业区域图的作图方法、典型示例分析和作业区域评价原则。 相似文献
18.
Sealing problems for reciprocating pumps or intensifiers operating at high pressures (above 100 MPa) may be solved by adopting a closely fitting externally pressurized sleeve. This paper presents an elastohydrodynamic (EHD) analysis for such high pressure sleeve type seals and examines the effects of structural and operational parameters on their high pressure performance characteristics. The effects of pressure on the viscosity and density of the working fluid are also considered in the analysis. The numerical results clearly indicate that the sealing efficiency of high pressure sleeve seals can be enhanced with elastic deformation of both the sleeve and the plunger. The effect of working pressure on the stiffness of the sleeve seal and the induced frictional force are also presented. The study of the effect of eccentricity on the radial stiffness shows that it leads to a large radial force and the plunger is pressed on the sleeve surface, hereby termed ‘hydraulic locking’. This phenomenon results in an increase in frictional forces which is one of the key factors for the limited working life of the seal. 相似文献
19.
热处理是重要的加工手段之一,也是焊接和电镀的重要工序内容,它可以改善金属材料的使用性能和工艺性能,充分挖掘材料性能潜力,节省加工成本,提高加工质量和产品使用性能。在工艺设计时应注意防止热处理缺陷的产生。 相似文献
20.
对一种利用Fe基纳米晶软磁合金薄带作为敏感材料的新型压磁式压力传感器进行了可行性研究。介绍了该传感器的结构、工作原理、输出特性以及主要参数的选择。然后通过试验,分析了传感器的静态特性以及温度变化对输出的影响。试验结果表明,该传感器的最大线性误差为2.22%(满量程),最大不重复误差为0.97%(满量程),未经放大的最大灵敏度为0.2073μV/Pa,零点每摄氏度温漂小于1.22%(满量程)。该传感器具有结构简单、工作可靠、成本低廉,以及测压范围宽等优点。 相似文献