共查询到18条相似文献,搜索用时 93 毫秒
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机械设备产生振动和噪音的因素有很多,要达到减振降噪的效果,就要针对各方面因素综合考虑,以获得良好的效果。本论文针对机械设计中减振降噪技术的应用进行探究。 相似文献
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电站汽轮机调节阀振动试验研究 总被引:2,自引:0,他引:2
针对电站汽轮机常用调节阀的不稳定和振动工况进行试验研究,利用微小型高频动态压力传感器等先进测试仪器,测量阀门内部流场,尤其是阀座喉部、阀瓣头部等关键部位,获得阀门流体诱发振动结论。在大压比、大升程条件下,喉部各测点的脉动压力不大,流动稳定。中小压比、中小升程时,压力脉动达到相对的最大值或变化最大,此时气流对阀瓣的作用力也达到最大。气流脉动一般含有小于几百Hz的主频,所以这种条件下气流与结构相对容易发生共振。 相似文献
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针对高压差下调节阀内的闪蒸空化引起的强振动和高噪声问题,设计了一种消声减振套筒,并对其级数、级间隙和孔径大小进行研究。首先从理论上确定套筒的级数和级间隙,然后建立三维模型,以连续性方程、三维雷诺平均N-S方程和基于各向同性涡粘性理论的k-ε方程组成调节阀内部流动数值模拟的控制方程组,采用结构与非结构网格相结合有限体积法对控制方程组进行离散,应用Fluent对各参数套筒结构调节阀内部流动进行数值模拟计算。结果表明,理论初步确定套筒级数的可行性;适当增大级间间隙与减小孔径大小,有利于高压差调节阀的消声减振,为高压差调节阀的设计提供参考。 相似文献
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对液压系统的流量脉动、压力脉动产生的机理进行了分析研究,重点分析了盲管在液压系统中的减振、降噪作用,并给出了盲管长度的理论计算方法,得到的结果可以为液压系统的减振、降噪研究提供理论参考。 相似文献
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介绍了某热电厂汽轮机高压调节阀受信号干扰、阀杆脱落、阀杆轴向转动、在热态工况无法打开及突然关闭等故障现象,在进行原因分析的基础上总结了处理措施,对其他机组生产运行与检修维护具有一定的参考意义。 相似文献
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通过对噪声产生机理的分析,确定了主蒸汽阀噪声的生成原因,介绍了几种降噪措施及其效果,对电厂管道设计和阀门选型具有借鉴意义。 相似文献
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针对改进进汽段的设计、提高机组经济性、降低机组噪声的目的,用数值方法研究了10 MW给水泵汽轮机组速关阀和调阀系统的全开工况下的流动和噪声。求解了全三维N-S方程和k-ε湍流模型得到进汽系统内部的稳态流场,从流场的速度分布云图、湍动能分布云图和涡量分布云图出发,分析了压力损失产生的原因,将瞬态分析得到的流体边界压力随时间的脉动通过傅里叶变换,转换成频域下的声压值,得到进汽系统内各个壁面的二级子噪声源的分布云图,并分析了调阀喉部处各频率下的声压大小。研究结果表明,进汽系统内的总压损达6.06%,其中速关阀部分产生的压损为1.98%,调阀部分产生的压损为4.08%,调阀喉部及折弯处为气动噪声辐射的主要位置,噪声辐射能量最大的频率为30 Hz。 相似文献
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汽轮机振动监测系统的设计与实现 总被引:1,自引:0,他引:1
马林联 《工业仪表与自动化装置》2009,(1):74-75
介绍了汽轮机振动监测系统的实现,重点介绍了监测系统软件的结构设计,以及该监测系统的特点。 相似文献
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In response to technical issues such as the ineffective noise reduction impact of balanced cage and single-seat control valves, the U-shaped noise reduction cage control valve is investigated and developed. In addition, its equal percentage flow properties and noise reduction impact are good, allowing it to effectively minimize the noise created by the change of fluid parameters of medium such as vapor, gas, and gas-liquid two-phase flow. The flow coefficient and flow properties were analyzed. The noise features of the medium air flow at small and large openings of 30% and 85% are simulated and analyzed, respectively. The pressure, velocity, and temperature of the inlet and outlet air, as well as the sound intensity maximum and sound power level maximum, are also analyzed with the opening curves. A small opening of 30% was selected, and the noise characteristics of cavitation generated by the medium water flow were simulated and analyzed. Together with the pressure and temperature change curves of the incoming water, the volume maxima and density minima of water are studied. The maximum sound intensity and sound power level of water are analyzed using the pressure and temperature curves of inlet water, as well as the cavitation coefficient and the degree of opening. The results of the trial for the pressure resistance of the valve body and the trial for the valve seat seal indicate that both the valve body strength and the valve seat seal meet the specifications. Comparing the noise trial results and simulation results reveals that the sound intensity and sound power level assessed by the trial and simulation are comparable, and the noise reduction impact of the control valve is positive. 相似文献
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为利用控制方法减小兆瓦级风机运行过程中塔架的振动量,对塔架结构动态特性和塔架激励源动态特性进行了分析研究。以某2 MW机组为例,进行了塔架振动情况评估。基于评估结果,设计了增加气动阻尼的塔架振动控制方法,并进一步设计了直接加阻的主动控制结构,结合振动过大时主动降功率运行手段,实现了塔架振动的控制器干预。在许继WRTS-800和PRDS-600仿真实验平台上进行了仿真验证和等效疲劳载荷计算;在实验风场进行了现场实验,并对实验数据进行了统计分析。研究结果表明,采用该方法,塔架等效疲劳载荷明显减小,主动控制减振效果明显。 相似文献
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Model errors in multiple-input multiple-output adaptive controllers for reduction of broadband noise and vibrations may lead to unstable systems or increased error signals. In this paper, a combination of high-authority control (HAC) and low-authority control (LAC) is considered for improved performance in case of such model errors. A digital implementation of a control system is presented in which the HAC (adaptive MIMO control) is implemented on a CPU and in which the LAC (decentralized control) is implemented on a high-speed Field Programmable Gate Array. Experimental results are given which demonstrate that the HAC/LAC combination leads to performance advantages in terms of stabilization under parametric uncertainties and reduction of the error signal. 相似文献