METHOD FOR MONITORING THE TECHNICAL CONDITION OF A DIESEL GENERATOR WHEN IN OPERATION

Abstract

A method for measuring vibration acceleration in three mutually orthogonal planes via vibration sensors. Vibration accelerations are measured at the monitoring points on an operational and knowingly fault-free diesel generator, and then vibration accelerations are measured at the monitoring points of a diesel generator in the course of its operation with prescribed intervals. Temperature and intensity of an ultrasonic signal are additionally measured at the same monitoring points, and the root mean square values of the ultrasonic signal intensity, temperature and vibration acceleration are determined. The measured vibration acceleration values are used to calculate the root mean square values of vibration velocity and vibratory displacement, the distances between clusters of preceding measurements are determined, and a conclusion on the operating state of the diesel generator is made. The method promotes timely detection of any operating defects through periodic measurements and comparison of calculations.

Claims

1. A method for monitoring the technical condition of a diesel generator when in operation, involving measurement of the vibration acceleration values at three mutually orthogonal planes with the use of vibration sensors installed at monitoring points on the diesel generator, characterized in that primary measurements of the vibration acceleration values are preliminarily performed at the monitoring points of a knowingly fault-free operational diesel generator, and then subsequent measurements of the vibration acceleration values are performed at the monitoring points on the diesel generator in the course of its operation with the prescribed intervals, with additional measurement of temperature and intensity of an ultrasonic signal at the same monitoring points and determination of the root mean square values of the ultrasonic signal intensity, temperature and vibration acceleration, and the root mean square values of vibration velocity and vibratory displacement are also calculated on the basis of the measured values; the obtained values are presented in the form of matrices, then the obtained root mean square values are normalized; calculation of the co-variation matrices and their singular decomposition are performed in order to determine the eigen vectors and the eigen values, then the obtained data are projected on the eigenvector components with formation of clusters corresponding to the measurements at each point within the space of eigenvector components, then the specified interval formed as the range of distance between the previous measurement clusters is determined, and a conclusion is made on absence of any faults in the diesel generator if more than 50% of the current measurement clusters fall within the specified interval, or presence of any malfunctions of the diesel generator if less than 50% of the current measurement clusters fall within the specified interval, or presence of any fault in the diesel generator if more than 50% of clusters are below the specified interval limits.

2. The method for monitoring the technical condition of a diesel generator according to claim 1, characterized in that the monitoring points of the diesel generator for installation of vibration sensors are selected on the diesel supports and fastening points, on the diesel case and in the areas close to location of the diesel supports, turbo compressors, water and oil pumps as well as on the generator supports and frame and its bearing blocks.

3. The method for monitoring the technical condition of a diesel generator according to claim 1, characterized in that additional monitoring points for measurement of the ultrasonic signal intensity are mainly selected on the cylinders and their high-pressure fuel pumps, the anchor ties of base bearings, the cam shaft sleeve-type bearings, the generator, the water and oil pumps.

4. The method for monitoring the technical condition of a diesel generator according to claim 1, characterized in that additional monitoring points for temperature measurement are selected on the generator bearing, the exhaust nozzles of the cylinders, the high-pressure fuel pumps, the inspection hatches, the housings of the diesel cooling water pump, the boost air cooling water pump, the oil pump and the generator.

5. The method for monitoring the technical condition of a diesel generator according to claim 1, characterized in that temperature is measured with the use of a thermal imager.

6. The method for monitoring the technical condition of a diesel generator according to claim 1, characterized in that the values of vibration acceleration, temperature and ultrasonic signal intensity are measured with the frequency of once per 3 months.

Description

[0028] After completion of the above-mentioned measurements the root mean square values of the ultrasonic signal intensity, temperature and vibration acceleration are calculated. Then the root mean square values of vibration velocity and vibratory displacement are calculated on the basis of the measured vibration acceleration values.

[0029] The obtained values are represented in the form of matrices, for example:

[00001]$\text{A}=\left[\begin{array}{c}\begin{array}{cccccc}{V}_{RMS}^X{}_1^1& V_{MAX}^X{}_1^1& V_{RMS}^Y{}_1^1& V_{MAX}^Y{}_1^1& V_{RMS}^Z{}_1^1& V_{MAX}^Z{}_1^1\end{array}\\ .Math.\\ \begin{array}{cccccc}{V}_{RMS}^X{}_1^i& V_{MAX}^X{}_1^i& V_{RMS}^Y{}_1^i& V_{MAX}^Y{}_1^i& V_{RMS}^Z{}_1^i& V_{MAX}^Z{}_1^i\end{array}\\ .Math.\\ \begin{array}{cccccc}{V}_{RMS}^X{}_1^K& V_{MAX}^X{}_1^K& V_{RMS}^Y{}_1^K& V_{MAX}^Y{}_1^K& V_{RMS}^Z{}_1^K& V_{MAX}^Z{}_1^K\end{array}\\ \ddots \\ \begin{array}{cccccc}{V}_{RMS}^X{}_L^1& V_{MAX}^X{}_L^1& V_{RMS}^Y{}_L^1& V_{MAX}^Y{}_L^1& V_{RMS}^Z{}_L^1& V_{MAX}^Z{}_L^1\end{array}\\ .Math.\\ \begin{array}{cccccc}{V}_{RMS}^X{}_L^i& V_{MAX}^X{}_L^i& V_{RMS}^Y{}_L^i& V_{MAX}^Y{}_L^i& V_{RMS}^Z{}_L^i& V_{MAX}^Z{}_L^i\end{array}\\ .Math.\\ \begin{array}{cccccc}{V}_{RMS}^X{}_L^K& V_{MAX}^X{}_L^K& V_{RMS}^Y{}_L^K& V_{MAX}^Y{}_L^K& V_{RMS}^Z{}_L^K& V_{MAX}^Z{}_L^K\end{array}\end{array}\right],$

Where

[00002]$\left\{V_{RM{S}_j}^{X^{\text{}\text{}\text{}\text{}\text{}i}}{V}_{MA{X}_j}^{X\text{}\text{}\text{}\text{}{}^i}{V}_{RM{S}_j}^{Y{}^i}{V}_{MA{X}_j}^{Y{}^i}{V}_{RM{S}_j}^{Z{}^i}{V}_{MA{X}_j}^{Z{}^i}\right\}$

are the root mean square values and the maximum values of vibration velocity in three mutually orthogonal planes recorded several times at the same points on the equipment, where K is the number of measurements and L is the number of points.

[0030] The values of temperature and ultrasonic signal intensity are represented in the form of similar matrices.

[0031] Then the parameters are normalized (so that the probabilistic average in each column corresponds to zero, and dispersion - to one), and the co-variation matrices are calculated:

[00003]$C_A=\frac{A{A}^T}{L}.$

[0032] The co-variation matrix is decomposed with the use of singular decomposition in order to obtain eigen vectors and eigen values

[00004]$C_A{U}_n={\lambda }_n{U}_n,$

where U.sub.n are eigen vectors (the maximum dispersion directions); λ.sub.n is the eigen value (the dispersion fraction of the parameter in the relevant vector direction).

[0033] Then the obtained data are projected on the eigenvector components with formation of the clusters corresponding to the measurements at each point within the space of eigenvector components. Then the specified interval formed as the range of distance between the previous measurement clusters is determined, and a conclusion is made on absence of any faults in the diesel generator if more than 50% of the current measurement clusters fall within the specified interval, or presence of any malfunctions of the diesel generator if less than 50% of the current measurement clusters fall within the specified interval, or presence of any fault in the diesel generator if more than 50% of clusters are below the specified interval limits.

[0034] The described method has been applied in diagnostics of diesel generator units of 15D-100, 12ZV40/48+S2445-12, ZVEZDA 6000BC-MTU types operated at Novovoronezh, Smolensk and Rostov NPPs and can be used for diagnostics of diesel generator units of ASD-5600, DG-4000, AS-803 and AS-808 types operated at other NPPs.

[0035] Application of the described method enables to determine the technical condition of a diesel generator promptly and to identify any malfunctions in a timely manner.