共查询到17条相似文献,搜索用时 328 毫秒
1.
2.
3.
4.
自动同步离合器的脱开过程 总被引:4,自引:1,他引:3
自动同步离合器脱开过程的研究是动力装置动力学研究中提出来的一个课题。本文用文献中提出的方法,对自动同步离合器在脱开过程中各运动参数的变化规律进行了分析计算,对反扭矩和反向阻尼的作用和影响进行了探讨,得出了对动力装置研究工作有价值的一些结论。最后,用国外的一些试验结果做了验证。 相似文献
5.
本文对燃气—蒸汽联合循环机组轴系布置方案进行了详细研究,将其分为普通单轴布置轴系、带有SSS离合器(同步自动离合器)的单轴布置轴系、多轴布置中的燃气轮机轴系和汽轮机轴系4种类型。并且分析了4种类型与常规机组汽轮机轴系的区别,并通过对某联合循环电厂轴系的典型振动故障分析,讲述了此方面研究的重要性。本文从现场振动故障诊断和理论研究两个方面总结了近些年联合循环机组轴系振动的研究进展,提出带有SSS离合器的单轴布置轴系和多轴布置中带有SSS离合器的汽轮机轴系是今后的研究方向。 相似文献
6.
7.
8.
9.
10.
1997年我段接连发生几起东风型机车风扇摩擦离合器故障。组装好的摩擦离合器短的用几个星期,长的用一至两个月就发生无法分离或闭合、离合失效、摩擦片破碎等故障,给我段检修工作造成很大的压力和摩擦离合器材料的不正常消耗。 东风型机车摩擦离合器是带动冷却风扇转动,使柴油机油、水温度保持在规定范围内的重要传动部件。冷却水温高时,使摩擦离合器闭合,主动轴通过摩擦离合器带动冷却风扇转动,当冷却水温降至规定值则断开摩擦离合器,冷却风扇停止工作。摩擦离合器发生故障导致柴油机油、水温度过高或过低,严重影响柴油机正常运转。从1997年5月到1998年3月,我段因摩擦离合器故障造成的临修7件,给安全生产带来了不利的影响,也使摩擦离合器材料频频告急。 相似文献
11.
本文介绍了水力发电装置中的最佳,高效、节能动力装置——新型泵水储能动力装置,以及该装置中的s.s.s.离合器。 相似文献
12.
鉴于高压直流输电系统逆变站最后断路器跳闸装置是非常重要的换流站直流系统控制设备,介绍了奉贤特高压换流站最后断路器保护的基本原理,针对系统调试期间该保护未正常动作的异常情况,通过分析现场故障录波图中各参数变化曲线得出调试时最后断路器保护未正确动作的原因是由于系统输送功率过小所致,并提出了相应的改进建议,使得在低功率系统调试时能起到测试最后断路器保护的作用,同时避免了设备损坏。 相似文献
13.
Dhiraj Kumar Singh S.K. Maiti Tanmay K. Bhandakkar R.K. Singh Raman 《International Journal of Hydrogen Energy》2018,43(27):12530-12542
The paper presents an axisymmetric finite element model to study hydrogen-assisted cracking (HAC) in a circumferentially notched tensile (CNT) specimen of a high-strength steel. The model includes an axisymmetric 2-D stress analysis coupled with an axisymmetric 1-D hydrogen diffusion analysis. Crack initiation is handled through cohesive elements whose strength is adjusted depending on the local hydrogen concentration. The model successfully predicted the critical SIFs of tempered AISI 4340 under different hydrogen charging conditions in rising displacement tests. Furthermore, the model is able to simulate of typical delayed failure of specimens under HAC conditions in constant load tests. Reported HAC of three different microstructures of AISI 4340 was simulated under rising displacement condition, and the respective model parameters were then also used to simulate crack initiation in the same microstructures under constant load condition. Closeness of critical SIFs from both the simulations indicates that the model parameters calibrated through slow strain rate tests are transferable to constant load situations. Moreover, it is shown that the present 2-D analysis, while being computationally advantageous, is an acceptable alternative of a 3-D model reported earlier. 相似文献
14.
介绍了某电厂锅炉高温再热器发生失效的基本情况,通过化学元素分析、力学性能试验、宏观检查、金相分析和电子探针微区成分分析等试验表明,管子外表面存在较明显的结垢现象,氧化物下的金属金相组织出现深2~3个的沿晶腐蚀裂纹,沿晶腐蚀产物中存在S元素综合分析认为,其失效类型为高温硫腐蚀,并提出了预防措施。 相似文献
15.
为研究某左右不对称灯泡贯流式厂房结构在静动力荷载作用下的位移、应力分布规律,采用三维有限元动力反应谱法对其进行抗震分析,计算中采用完全二次项组合(CQC)法考虑双向的扭转耦联作用,应用Westergaard公式考虑地震动水压力。结果表明,该厂房位移应力分布合理,可为同类工程提供参考。 相似文献
16.
《International Journal of Pressure Vessels and Piping》2005,82(8):638-648
The purpose of this paper is to study the plastic limit moment of nozzles in cylindrical vessels with different d/D ratios under out-of-plane moment loading. Three full size test models were designed and fabricated. A 3D nonlinear finite element numerical simulation was also performed. A twice-elastic-slope plastic moment on the nozzles was obtained approximately by use of load–displacement and load–strain curves. The results show that plastic loads determined by test and numerical simulation methods are in good agreement. The results can serve as a basis for developing an advanced design guideline by limit analysis for cylindrical vessels with a nozzle under external loads. 相似文献
17.
《International Journal of Pressure Vessels and Piping》1998,75(8):589-601
The local stress–strain state (SSS) near the crack tip and its connection with the crack tip opening displacement and J-integral under biaxial loading have been studied by finite element methods in elastic–plastic finite strain statement. Numerical investigations have been performed for various crack lengths and two types of biaxial loading (tension and bending) under conditions of small- and large-scale yielding. To predict the biaxial loading effect on cleavage fracture toughness, the procedure has been elaborated, this being based on the revealed regularities for SSS near the crack tip under biaxial loading and brittle fracture criterion proposed earlier. Prediction of the biaxial loading effect on cleavage fracture toughness has been performed as applied to reactor pressure vessel steel. The calculated results have been compared with available experimental data. Alternative approaches for prediction of the biaxial loading effect on fracture toughness have been discussed. 相似文献