微波叶尖间隙测量传感器的计算分析

介绍了利用微波相位法测量短距离位移的工作原理,建立了一种基于此原理的谐振腔结构微波传感器模型,并完成了模拟计算。分析了微波传感器测量发动机叶尖间隙的能力,和高温环境对传感器性能的影响。结果显示此传感器能够在高温环境下完成0~6 mm范围内的高精度位移测量,可以很好的应用于航空发动机叶尖间隙的测试。     

燃气轮机压气机冷却技术研究

详细分析了几种常用的燃气轮机压气机冷却技术的特点，给出了燃气轮机进气冷却方案选择的依据。     

某压气机钛合金叶片掉块失效分析

通过对某高压压气机工作叶片掉块的宏观、微观分析,认为叶片的掉块原因是叶片长度超差使叶尖与机匣产生摩擦,磨屑堆积在叶背产生裂纹,形成疲劳源,最后造成疲劳裂纹扩展.     

旋转状态下微波叶尖间隙传感器校准影响因素分析

主要针对应用于发动机叶尖间隙测量的微波叶尖间隙传感器的校准需求,对测量原理、传感器的校准原理等进行了详细阐述,并分析了转速和回缩值等对校准结果的影响。为微波叶尖间隙传感器的进一步优化设计及应用提供了数据依据。     

叶片叶尖间隙测量的光纤传感器

根据叶尖间隙测量的要求,设计了一种新型的光纤传感器。它采用了单光纤传光、多组光纤束接收散射光的结构。发射光纤位于中心,周围均布多组接收光纤。通过各组接收光纤光强的比值运算,消除了叶尖表面反射率变化对测量结果的影响,也可减小叶尖表面与传感器端面夹角给测量结果带来的影响。在转速同步传感器的配合下,该传感器可以实时测量所有叶片的叶尖间隙。当叶片转速在0—12000r／min之间变化时,叶尖间隙的测量范围为0-3mm,测量精度为25μm。     

某发动机压气机四级转子

对某发动机经８０ｈ试车后四级压气机３５＃转子叶片榫头折断故障做了分析，经金相与扫描电镜观察和模拟试验，使故障再现，分析认为，是加工配合过盈，局部接触应力过大出现微振磨损所致，并提出改进措施。     

燃气轮机压气机滤网压差高的原因及对策

自然环境中的空气不可避免的会含有各种各样的杂质,这些杂质在进入燃气轮机后将影响燃气轮机的安全和经济运行,而燃气轮机压气机滤网的主要作用就是给燃气轮机的压气机提供过滤过的清洁的空气,以满足燃气轮机在当地环境下的运行要求。文章分析了燃气轮机压气机滤网压差高的原因,并根据其原因提出了相应的对策。通过某电厂的实例分析,进一步总结了具体的经验,对以后其他电厂机组运行具有借鉴和参考意义。     

探析国外航空发动机叶片叶尖间隙检测技术

国外主要应用的叶片叶尖间隙测量技术包括放电探针法、电容法、涡电流法、激光法、超声波法以及微波叶尖间隙测量法等,本文重点介绍国外主要研究和应用的微波法、超声法、电容法和激光法。     

基于调频电容式技术的运动间隙的测量

针对航空发动机的压气机叶片顶端与机匣运动间隙的测量需要 ,研制了一套基于调频电容式技术的测量系统。首先 ,运动间隙通过探头—电缆组件转换成电容信号并把它引出接至振荡电路中 ,再通过单片机P87LPC76 2采集振荡器输出的频率信号并进行相应的换算 ,最后得出所需测量的间隙值。     

叶顶间隙对氮低温透平膨胀机效率影响的数值模拟

氮低温制冷循环系统为高能同步辐射光源提供80 K温区冷量,其最核心的部件为氮透平膨胀机,透平叶顶间隙会改变流场分布,对效率产生较大影响。首先根据设计工况初步确定了氮透平的几何结构,随后利用数值模拟对流场进行计算,研究了叶顶间隙参数对流场分布以及整体效率的影响。结果表明,叶顶间隙的存在会使工作轮入口叶顶出现涡流,改变流场分布。在等叶顶间隙情况下,叶顶间隙相对出口叶高小于1.5%时,间隙每增加0.5%,等熵效率降低1.5%左右;在不等叶顶间隙情况下,径向间隙对透平效率的影响要明显大于轴向间隙。     

Failure Analysis of High-Pressure Compressor Blade in an Aero Gas Turbine Engine

Failure of high-pressure compressor rotor blade in an aero gas turbine engine is analyzed to determine its root cause. Forensic and metallurgical investigations are carried out on the blade and failed parts. The failure of the platform ladder is found to the first in the chain of events that led to the compressor blade failure. The mode of failure in the blade is found to be fatigue and has originated from the damaged region on the leading edge caused by dislodgement of platform ladder. The failure has caused extensive damages in high-pressure compressor module and also in downstream turbine blades as a secondary effect.     

Failure Analysis and Repair of a Catastrophically Damaged Gas Turbine Compressor Disk Using SEM Technique and CFD Analysis

During a major overhaul of an 85?MW gas turbine unit in Iran-Rey power plant, 39 cracks were detected with different lengths and locations on the compressor disk of stage 11. All of the cracks initiated from the dovetail regions. Preliminary visual inspections and further micro-fractography using the scanning electron microscope demonstrated that the fretting fatigue phenomenon was the main cause of failure. Four repair methods were suggested to restart the unit. The first one was to remove all of the cracks from the disk by machining, or the so-called blending. The second, third, and fourth ways were to remove the entire rotor blades of stage 11, to remove the entire rotor and stator blades of the stage 11 simultaneously, and to remove those rotor blades of stage 11 corresponding to the damaged dovetails, respectively. Although the first way of solution was initially carried out on the damaged disk, the first author offered that restarting the unit with the blended disk is not reliable enough because of the presence of a large number of repair points on the disk. Using the numerical investigations based on the computational fluid dynamics, it was found that only the second suggestion (i.e., removing the entire rotor blades of the stage 11) might be applicable. Ultimately, the entire stage 11 rotor blades were removed from the blended disk, and the gas turbine unit was successfully restarted without encountering abnormal operation. Although the performed process resulted in approximately 20% output power loss compared with the unit's power before the blades' removal, the unit was quickly restored to be ready to restart, and the electric power could be generated during the period of peak consumption.     

Fatigue Failure of LP Compressor Blade in an Aero Gas Turbine Engine

Failure of low-pressure compressor rotor blade in an aero gas turbine engine is analyzed to determine its root cause. Forensic and metallurgical investigations are carried out on the blade failed. The failure of the first stage rotor blade is found to be the first in the chain of events that led to the engine failure. The mode of failure in the blade is found to be fatigue and has originated from the mounting lug fillet region due to high stress concentrations. The failure has caused extensive damages in low-pressure compressor module and also in downstream modules as a secondary effect. Remedial measures are also suggested to prevent such failures.     

LM5000燃机振动研究

燃气轮机发电机组振动高问题比较常见，原因也比较复杂，通过对LM5000燃气轮机474—142号机组高压压气机振动高进行原因分析，并通过现场动平衡的方法来降低高压压气机的振动。     

Numerical Simulation and Technological Parameter Optimization for Quenching Process of a Gas Turbine Compressor Disk Based on Metallo-Thermo-Mechanics

Thermal, mechanical and microstructural phenomena are involved in the process of steel quenching. Based on the coupled metallo-thermo-mechanics theory, a calculation model has been developed in this study to simulate the quenching process of a gas turbine compressor disk by finite element method. The thermal physical and mechanical properties were treated as a functions of temperature. Moreover, a series of subroutines were developed on the MARC software platform. Consequently, simulated results on temperature, internal stress and distortion during the quenching were illustrated. With the aid of the simulated results, an optimum quenching scheme was proposed. The quenching process simulated in this study appears to be a promising tool in design of heat-treatment processing parameters for gas turbine compressor disks.     

DH型压缩机齿轮-轴承-转子系统动力学分析

基于转于动力学和齿轮啮合基本原理，建立了一般齿轮稠合轴系弯扭耦合振动方程。对某DH型压缩机转于系统进行了详细地动力学分析，提出了改进该类压缩机转于系统设计的具体建议。