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旋转 失速 以及 基于 统计 处理 离心 压缩机 制度 轨制 参数 检测 方法 法子 中文

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旋转失速和基于统计处理的离心压缩机制度参数的检测方法[中文2310字],旋转,失速,以及,基于,统计,处理,离心,压缩机,制度,轨制,参数,检测,方法,法子,中文

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中文 2310 字.旋转失速和基于统计处理的离心压缩机制度参数的检测方法值得注意的是，涡轮压缩机失速和以不同形式气动力不稳定为特性的迹象表征中的一个最有前途的趋势是统计信号处理方法和使用。提出了一个使用统计功能的程序，分析涡轮压缩机非平稳信号压缩性质和基于信号制度参数计算共变的失速启示迹象。基于分析不同结构离心压缩机共变信号参数而提供的结果证明这个参数适用于检测压缩气动不稳定现象。文中提出的程序成功用于离心压缩机自动系统的特殊软件实践形式中。压缩气动不稳定性的检测设备是当代系统的一个重要组成部分，提供了涡轮压缩机的安全运行。目前，反应失速发生的电子设备（失速指标）被广泛使用。他们不断分析涡轮压缩机制度参数的传感器信号，目标是揭示气动不稳定性（失速）的初始信号，并且他们向控制系统发出一个信号以便采取撤离压缩机远离危险状况的极端措施。改善检测涡轮压缩机失速方法和以不同形式气动力不稳定（失速和喘振）为特性的迹象表征中的一个最有前途的趋势是统计方法处理压缩机制度参数的传感器信号1 。在信息科学中，统计检测方法所取得的成就是众所周知的，通过高效率和抗干扰性来区分。鉴于此，有必要注意文献 3，在文献 3 中旋转喘振的观察是在计算通过压力传感器信号的自相关函数基础上从而分析短暂迹象和前失速来完成的。然而，这种方法还没有得到广泛的应用。检测失速的基本方法是计算实时域平均值 和分散信号 2：x2x； ， Nix1Niix12)(（1）式中 是 i 信号； N 是一个决定平均时间间隔的数。x一种通用的失速初始标准被认为是超过了传感器信号的一些分散阈值。2rethr信号的相对离散度（变异系数）是通过方程 计算的。22rex由于信号源可能在流量计或排气压力中使用压力降传感器。这个准则在失速指标的应用软件形式中得到体现，它在运行过程中显示了良好效果。使用统计功能来分析涡轮压缩机短时压缩的程序发展，是失速信号的学习和基于计算制度参数信号相关性方法的发展。在分析过程中国，使用不同涡轮压缩机制度参数，这些参数在失速测试中以数字形式书写。对于二维参数（x,y）在前失速期和失速期存在相关趋势，有下列计算：平均值 有方程x（1）确定， 由相似方程确定y ，Niy1-并且协方差x,y 由下列方程确定 Ni iiyxyxv122)(),co作为一个刻画了短时水平的参数来说，一个相对共变无量纲参数就被制定了：。 yxre,cov（2）进行这些研究，从离心压缩机不同结构的失速测试中得到共变数据，在分析共变数据基础上，在不同压缩媒体上运行，根据检测短时压缩来显示这个参数的适用性。以下条件被当做初始失速标准来使用： ，其中 是某个阈thrrecovthrcov值共变。分析表明，对于失速的检测有可能使用流量计设备和压缩机排气压力中的压力降信号的有效共变，流量计设备中的压力降信号和主电动驱动的电流强度，流量计设备中的压力降信号和转子轴向剪切，流量计设备中的压力降信号和转子旋转频率（使用涡轮作为压缩机驱动力） 。图 1 所示是基于共变的失速检测方法的效率。与基于自相关和色散分析的单一参数方法相比，该方法具有很多优点。这些优点与在最低限度群体行为的两个离心压缩机参数的分析有关。这使得人们有可能增加检测失速错误反应算法的阻力，这个错误反应没有压缩气动短时发展的敏感度的减少。在许多情况下，当失速在本质上隐藏或者当气动不稳定性在旋转喘振的发展中受限时，该方法给出了检测的有用结果，而其他方法都不起隐式作用。此功能对于带有燃气轮机驱动的离心压缩机具有重要支持（轴承） 。在这些情况下，气动不稳定性现象并不伴随自振动失速和他们固有的排气压力和流量脉动，使得失速测试和失速限制决定非常困难。基于计算共变的气动不稳定性诊断方法的使用，在这些情况下几乎无法替代，并且他们有可能正确地决定失速限制。由公式（2）计算的共变参数的信息量在数据例子上已被证实获得增压器NTS-12/56-1.44（GPA-12 乌拉尔） ，在堪萨斯州彼尔姆。这些研究表明，和信号源的正确选择一起，转化器的采样周期（离散频率）和读取共变所需的点数量，决定了时间间隔，用这种方法可以有效地检测。基于该方法提出的检测算法的普遍性通过不同型号压缩机所有测试例子的工作稳定性被证实，这些不同类型的压缩机具有在宽范围拖延振动频率的改变，而且使用不同不同类型的传感器作为信号来源。作为工作的结果展开，离散信号的最佳频率以及协方差和分散性读取的点数量已被确定。研究表明，在读取时间间隔的相对最佳值的减少降低了失速检测算法的效率，并增加了噪音和干扰引起的误操作概率。反过来，间隔的增加导致算法的快速反应恶化和降低灵敏度。应当指出，对于算法的可靠运行，有必要在整个间隙的每一步转换器信号采集时计算协方差参数，例如，完成连续信号的实时处理规模。该算法可能引入到一个离心压缩机自动系统中， “前兆失速”情况（旋转失速的开始）的一个错误提示器的额外“设置” ，这些都低于在一个开放的旁路电枢实现预防控制信号的阈值。基于计算协方差的检测离心压缩机失速主要程序的优点如下：1 失速检测的高可靠性和高效率；2 抗噪声和抗干扰；3 对于一个自动系统的当代商业可编程控制器在时间范围实际执行的可能性。为了在离心压缩机控制系统中引入失速检测方法4，专用软件的开发使我们能够实时检测失速所需时间范围的统计函数的计算。这可能为国内外的商业微处理控制器的实际执行创建适用的软件。图 2 所示的是用于压缩机自动系统的失速指示器。目前几乎所有的离心压缩机自动系统都是由 Kazankompressormash 生产的，该自动系统配有失速指示器。这些指示器要么集成到在应用程序和高速模块为输入模拟信号以特殊编程单元为形式的主 PLC 控制器上，要么集成到专为这个目的而开发的单独微处理器控制器上。这些指示器可能由四种算法（三个协变和一个离散）同时检测出失速。为了检测失速现象而引入基于概率方法的失速指示器，已经能够增加离心压缩机失速保护系统的有效性和可靠性。METHODS OF DETECTING ROTATING SURGE AND STALL BASED ON GROUP STATISTICAL TREATMENT OF CENTRIFUGAL COMPRESSOR REGIME PARAMETERSYa. Z. Guzelbaev and A. L. KhavkinIt is noted that one of the most promising trends in the field of detecting turbocompressor stall and revelation of the signs that characterize different forms of the development of gas dynamic instability (stall and rotating surge) is the use of statistical processing methods and signals. A procedure is presented for using statistical functions for analyzing the nonstationary nature of compression in turbocompressors and revelation of signs of stall based on calculating covariation of signals of regime parameters. Results are provided for studies based on analyzing covariation of the signals of regime parameters for centrifugal compressors of different construction that demonstrate the suitability of this parameter for detecting the phenomenon of compression gas dynamic instability. The procedure proposed is used successfully in practice in the form of special software for stall signalers used in centrifugal compressor automation systems.Devices for detecting gas dynamic instability of compression are an important part of contemporary systems providing safe operation of turbocompressors. Currently, there is extensive use of electronic devices (stall indicators) that react to the start of stall. They continuously analyze transducer signals of turbocompressor regime parameters with the aim of revealing signs of the start of gas dynamic instability (stall) and they send a signal to the control system in order to take extreme measures for withdrawing the compressor from dangerous regimes.One of the most promising trends in the field of improving methods for detecting turbocompressor stall and revelation of the distinguishing signs that characterize different forms of the development of gas dynamic instability (stall and rotating surge) is the use of statistical methods for processing transducer signals of compressor regime parameters 1. In information science, the achievements of statistical detection methods are well known, distinguished by high efficiency and resistance tointerference. In view of this, it is necessary to note work in 3 in which observation of rotating surge is carried out by analyzing the signs of transience, preceding stall, on the basis of calculating the self-correlation function of the signal from the pressure transducer. However, this method has not been used widely.A method of detecting stall is proposed based on calculation on a real time scale of the average value x and dispersion of the signal 2:； Nix1Niixx122)(where x is signal of the ith reading; N is a number determining the averaging time aperture.A criterion for the start of stall is considered to be exceeding the relative dispersion of the transducer signal for some threshold dispersion 2rethrAs sources of signals it is possible to use pressure drop transducers in a flowmeter device or the discharge pressure.This criterion was realized in the form of applied software for stall indicators and it showed good results during operation.Development of a procedure for using statistical functions in order to analyze compression transience in turbocompressors is the study of signs of stall and development of methods based on calculating the covariation of regime parameter signals. During analysis, there was use of different turbocompressor regime parameters written in digital form during stall tests. From two parameters (x, y), having correlation tendencies in the prestall and stall periods, there was calculation of the following: the average value x by Eq. (1), y by a similar equationNi1-and covariation covx, y by the equation Ni iiyxyxv122)(),coAs a parameter that characterizes the level of transience, a dimensionless parameter of relative covariation was for mulated:。 yxre,cov（2）The studies performed,based on analyzing covariation data,obtained in stall tests for centrifugal compressors of different construction, operating on different compression media, demonstrated the suitability of this parameter for detecting compression transience.The following condition was used as a criterion for the start of stall:, ，where is some threshold covariation.thrrecovthrcovAnalysis showed that for detection of stall it is possible to use effectively covariation of pressure drop signals in the flowmeter device and compressor discharge pressure, signals of the pressure drop in the flowmeter device and currentstrength of the main electric drive, signals of the pressure drop in the flowmeter device and rotor axial shear, signals of the pressure drop in the flowmeter device and rotor rotation frequency (with use of a turbine as the compressor drive).The efficiency of the stall detection method based on covariation is shown in Fig. 1.This method has a number of advantages over single-parameter methods based on self-correlation and dispersion analysis. Advantages are connected with the fact that the group behavior as a minimum of two centrifugal compressor parameters is analyzed. This makes it possible to increase the resistance of the algorithm for detecting stall to false responses without a reduction in sensitivity to the development of compression gas dynamic transience. In a number of cases when stall is implicit in nature or when gas dynamic instability is limited to the development of rotating surge, the method proposed gives positive results for detection whereas other methods are inoperative. This feature is important for centrifugal compressors with a gas turbine drive having magnetic supports (bearings).In these cases, the phenomenon of gas dynamic instability is not accompanied by stall self-vibrations and inherent to them marked discharge pressure and flow rate pulsations, that makes stall testing and determination of the stall limit very difficult. Use of diagnosis methods for gas dynamic instability, based on calculating covariation, in these cases are almost without an alternative and they make it possible to determine the stall limit correctly.The informativeness of the covariation parameter, calculated by Eq. (2), has been confirmed on the example of data obtained with stall tests of a booster NTs-12/56-1.44 (GPA-12 Ural) at KS Permskaya.These studies demonstrated that with correct selection of signal sources, the sampling period (discretization frequency) for the transducer and the number of points for reading covariation, determining the time aperture, detects stall effectively by the method proposed.The universal nature of detection algorithms based on the proposed method is confirmed by the stability of work on all test examples of compressors of different types with a change in the frequency of stall vibrations over wide limits and the use of different types of transducers as signal sources.As a result of the work carried out,optimum frequencies for signal discretization and the number of points for reading dispersion and covariance were determined. Studies showed that a reduction in time aperture for reading the relative optimum value reduces the efficiency of stall detection algorithms and increases the probability of false operation caused by noise and interference. In turn, an increase in the aperture leads to worsening of the rapid action of algorithms and reduces sensitivity.It should be noted that for reliable operation of algorithms it is necessary to calculate covariance parameters over the whole aperture at each step of transducer signal sampling, i.e., to accomplish continuous signal processing on a real time scale.The algorithm makes it possible to introduce into a centrifugal compressor automation system a warning indicator for the “prestall” condition (start of rotating surge) in the for of additional “settings” that are lower than the threshold value for working out the preventative control signal in an open bypass armature.The main virtues of algorithms for detecting stall in centrifugal compressors based on calculating covariance are as follows: the high reliability and efficiency of stall detection; resistance to noise and interference; the possibility of practical implementation on a real time scale in contemporarycommercial programmable controllers for automation systems.In order to introduce methods for stall