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结合国华准格尔电厂1号机组3号轴瓦频繁出现的间歇性振动问题,对机组的轴系振动进行了在线监测和数据分析,提出了消除机组振动爬升和碰磨振动的技术措施。实施这些技术措施后,现场实验及运行结果表明,本文提出的消除该类机组振动爬升和碰磨振动的技术措施是非常有效的。 相似文献
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针对核电660MW汽轮机轴承低频振动问题,通过改变机组转速、功率及润滑油压等试验,分析了低频振动特征,指出转子轴向低频振动引起可倾瓦轴承低频振动。通过建立转子轴向约束简化模型,分析汽轮发电机转子轴向低频振动机理为推力轴承油膜失稳及轴向扰动力引起转子轴向低频共振,并与可倾瓦轴承油膜失稳及瓦块颤振两种故障模式进行了对比。对汽轮机转子轴向低频振动及其引起的可倾瓦轴承低频振动,提出调整推力轴承间隙的措施并消除了低频振动。 相似文献
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对发生低频振动的某200MW汽轮机进行了试验分析,找出了产生低频振动的原因,并提出了一些解决措施,取得了满意效果。通过实践,对这类机组如何避免产生低频振动的问题,向设计制造部门提出了设计支承系统时的建议。 相似文献
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某机组在基建调试阶段首次启动过程中,中速暖机1200r/min工况下振动缓慢爬升,15分钟后振动急剧增长,被迫打闸停机。通过试验分析,明确诊断出机组振动故障原因是活动式密封油挡发生碰磨所致。去掉活动式密封油挡后,再次启动完全消除了该机组的振动故障,使机组试运工作得以顺利进行。 相似文献
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为掌握某混流式水轮发电机组的运行稳定性情况,对该机组进行现场稳定性试验。从测试数据时域频谱分析结果可看出,机组在80~120 MW负荷工况运行时,上导摆度、水导摆度及顶盖振动与尾水压力脉动有相同的频率特性,且振动摆度明显增大,主要由低频涡带引起。根据变负荷试验数据将该机组在试验水头下的运行区域划分为小负荷工况区、涡带工况区和稳定工况区,并根据试验机组的结构特性及运行特性,结合现场试验数据,提出了该机组振动保护控制策略,为机组安全运行提供依据和保障。 相似文献
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J. N. Sharma 《热应力杂志》2013,36(7):650-666
The governing equations of flexural vibrations in a transversely isotropic thermoelastic beam are derived in closed form based on Euler–Bernoulli theory. The out-of- plane vibrations have been studied under different beam dimensions and boundary conditions. The analytical expressions for thermoelastic damping and frequency shift of vibrations are obtained. The damping and frequency shift of beam vibrations significantly depend on thermal relaxation time and surface conditions at resonance. The expressions for displacement and temperature fields in the beam resonator are obtained. Some numerical results with help of MATLAB software have been computed and presented graphically for silicon material beams. 相似文献
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增强型地热系统(enhanced geothermal system, EGS)以干热岩热能的开采和利用为目的,正逐渐成为世界各国的重点研究对象。除了建立EGS野外试验场开展实际场地研究和技术示范外,亦有必要开展相关的室内实验研究,研究或验证相关关键技术,为野外场地建设提供理论基础和技术支持。本课题组自主研发了模拟地下真实环境的实验系统,开展了尺寸为400 mm × 400 mm × 400 mm的花岗岩水力压裂实验,通过声发射事件监测到的声发射数据,分析了裂缝的扩展规律,并进行了初步的水力连通实验,探讨了各采出井的流量分配,研究了从注入井到生产井的水力连通特性。结果可为数值模拟提供基础数据,为野外试验场地的建设提供参考。 相似文献
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针对炼油装置能耗高的问题,通过一系列的节能降耗、流程优化和技术创新,取得了明显的效果.使炼油装置,特别是在炼油二次加工装置不断增加的情况下,吨原油加工消耗不断下降. 相似文献
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P. K. Sharma 《热应力杂志》2017,40(2):185-197
In this article, a model concerning free vibrations of spherically symmetric, thermoelastic, isotropic, and functionally graded sphere has been developed and analyzed in the context of linear theory of generalized thermoelasticity with one relaxation time. Laplace transform has been used to solve the problem which yields natural frequencies of free vibrations without performing inversion of the transform. The analytical results for coupled, uncoupled, and homogeneous spheres have been deduced as special cases of the general case. Natural frequencies of first 10 modes of vibrations have been obtained for different values of grading index of cobalt material regarding coupled thermoelastic, generalized thermoelastic, and elastic functionally graded spheres. The frequency shift and thermoelastic damping for Fourier and non-Fourier processes of heat propagation, temperature change, radial, and hoop stresses have been presented graphically. It has been analyzed here that grading index parameter helps in detecting the strength of signals in such material devices and the thermal relaxation time contributes in improving the quality of signals. The analysis also leads to the fact that grading index parameter is useful from design point of view and it can be tailored to specific applications for controlling the stress. 相似文献