RU2002130210A - METHOD FOR DETERMINING THE PARAMETERS OF OSCILLATIONS OF TURBO SHOWER BLADES - Google Patents

Claims (2)

1. The method of determining the vibration parameters of the blades of turbomachines, based on the non-contact reading of information on vibrations of rotating blades, which consists in installing two peripheral sensors on the turbomachine body at a basic distance along the path of rotation of the edges of the blades, registering the moments of the peripheral section of the blade past the sensors located at the base distance in the circumferential direction, the time intervals for the passage of the i-th blade from the 1st to 2nd sensors (between the sensors) are calculated, which differ that two peripheral sensors are installed on the turbomachine body at a basic distance (for example, at the distance of the installation step between the blades) along the path of motion of the edges of the blades, additionally measure the drift velocity of the blades and additionally calculate the time intervals between the moments of passage of the i-th and i + 1 blades in front of the 1st sensor, of which the first group of additionally measured time intervals is composed, the time intervals between the moments of passage of the i-th and i + 1 blades in front of the 2nd sensor, of which I the second group of additionally measured time intervals, the time intervals between the moments of passage of the i-th blade in front of the 2nd sensor and i + 1 blades in front of the 1st, of which the third group of additionally measured time intervals are composed, average values are calculated over the corresponding measured time intervals , drift linear velocities of the peripheral section of the i-th scapula, calculate the intrinsic displacements of the i-th scapula during the time T _i , accumulate a statistical set of intrinsic displacements of the i-th scapula, the volume of which is is divided by the specified accuracy and reliability, the largest deviation of the i-th blade A _i is determined by finding the difference between the maximum and minimum values of the proper displacements of the i-th blade, three groups of different steps are formed, corresponding to groups of additionally measured time intervals, they accumulate a statistical set of different steps, the volume of which is determined prescribed accuracy and reliability, for each pair of adjacent blades in all groups accumulated raznoshagovostey determined magnitude A _{i, i + 1} raznoshago spine, define an additional set of A $\genfrac{}{}{0ex}{}{\text{D}}{\text{i}}$ greatest deviations of the impeller blades from the recurrence relation

for i> 1, where N is the number of blades in the wheel, from the obtained for each blade values of the largest deviations A _i and A $\genfrac{}{}{0ex}{}{\text{D}}{\text{i}}$ judge the amplitude of the vibration displacements of each blade, determine the vibration velocities of each blade, form a statistical set of vibration speeds of each blade, the volume of which is determined by the specified accuracy and reliability, determine the amplitude of the vibration velocity from each statistical set of vibration velocities for each blade, calculate the ratio of the amplitude of the vibration velocity of each blade to the amplitude of the vibration displacement of the same blade , and the values obtained are used to judge the frequency of vibration displacement of each blade. 2. The method according to claim 1, characterized in that it further installs a third peripheral sensor at a basic distance from the closest sensor from a pair of sensors along the path of the edges of the blades, additionally record the moments of passage of the peripheral section of each blade in front of the 3rd sensor, and additionally calculate the intervals time between the moments of passage of the i-th blade from the 2nd to the 3rd sensor (between sensors), of which make up the fourth group of additionally measured time intervals, time intervals between moments passage of the i-th and i + 1 blades in front of the 3rd sensor, of which make up the fifth group of additionally measured time intervals, the time intervals between the moments of passage of the i-th blade in front of the 3rd sensor and i + 1 blades in front of the 2nd, from which comprise the sixth group of additionally measured time intervals, the time intervals between the moments of passage of the i-th blade in front of the 3rd sensor and i + 2 blades in front of the 1st, of which comprise the seventh group of additionally measured time intervals, the time intervals between the moments of i- th lope ki from the 1st to the 3rd sensor (between two sensors), of which make up the eighth group of additionally measured time intervals, calculate the average, during the corresponding measured time intervals, drift linear velocities of the peripheral section of the i-th blade, additionally for each the blades form two groups of additional proper displacements, accumulate a statistical set of additional proper displacements of the i-th blade, the volume of which is determined by the given accuracy and reliability, determine t the second additional set of the largest deviations of each i-th blade in the statistical set of additional proper displacements of the i-th blade, for each pair of adjacent blades form two groups of additional multi-steps, accumulate a statistical set of additional multi-steps, the volume of which is determined by the given accuracy and reliability, for each pair adjacent blades in all groups of accumulated additional divergences determine the amplitude A $\genfrac{}{}{0ex}{}{\text{DR}}{\text{i, i + 1}}$ additional differences, determine the third additional set of the largest deviations of each individual blades A $\genfrac{}{}{0ex}{}{\text{3D}}{\text{i}}$ impeller from the middle position according to the formula

for i> 1, where N is the number of blades in the wheel, for each pair of adjacent through one blades find additional adjacent different steps, accumulate a statistical set of additional adjacent different steps, the volume of which is determined by the given accuracy and reliability, for each pair of adjacent through one blades in the group of additional adjacent different steps, determine the amplitude A $\genfrac{}{}{0ex}{}{\text{DSR}}{\text{i, i + 2}}$ additional adjacent differences, determine the fourth additional set of the largest deviations of each individual blades A $\genfrac{}{}{0ex}{}{\text{4D}}{\text{i}}$ impeller from middle position a) for odd blades:

for j≥2, where L is the number of odd blades in the wheel, b) for even blades:

for j≥2, where M is the number of even blades in the wheel, a series of values of the largest deviations from all the sets of the largest deviations is formed for each blade, the amplitude of the vibration displacements of each blade is judged by the largest value from the series of values of the largest deviations, additional values of the vibration velocity of each blade are determined, from which 2- statistical statistical set of vibration velocities for each blade, the volume of which is determined by a given accuracy and reliability, for each blade, the 2nd measurement result p the amplitude of the vibration velocity as the difference between the maximum and minimum values of the 2nd set of vibration velocities, select the highest value from the 1st and 2nd measurement results of the amplitude of the vibration velocity, calculate the ratio of the maximum value of the amplitude of the vibration velocity of each blade to the amplitude of its vibration displacement, and judge by the obtained values vibration frequencies of each blade.