Research of influence of random change of annular seal parameters on efficiency of centrifugal pump

Determination of Reliability of Rotor-Annular Seals System by Theory of Runs of Random Functions

“…It is shown substantial influence of pressure drop, which throttled on a seal, and values of free-running frequency of the system on its reliability. Formula (11) gives an estimation from below for the function of reliability, thus for the hi-reliability systems this estimation will be near enough to the exact value, if the casual process ) (t U is ergodic stationary normal process. Through the erosive wear of seal surfaces in the process of exploitation of pump there is an increase of middle radial gap (and also geometry of gap changes), that increase reliability from one side, and from other diminishes its efficiency.…”

“…. As a numeral calculation showed the erosive increase of gap value in time work to the pump rises "rotor-annular seal" system reliability, but as it is shown in [11] substantially diminishes its efficiency. It means that in future the solving of optimization problem on the basis of set criteria is needed.…”

“…Thus to current or middle repair the reliability of system falls: if value of working frequency below freerunning frequency of the system -up to 17 %, if working frequency is after an free-runningup to 80%. It does not follow from this that a pump will break ranks, but because of high-frequency vibrations of rotor in stationary sleeve of the seal, there will be an higher wear of sealing surfaces (and also change of their geometry), that will influence on an flow rate through annular seal and accordingly on general coefficient of pump efficiency, as it shown in work [11].…”