| 摘要 |
PROBLEM TO BE SOLVED: To provide a diagnostic method for centrifugal pump capable of recognizing a cause of reducing performance even if the pump is disassembled and capable of estimating a proper parts replacing time.SOLUTION: In a centrifugal pump having wear components including a wear ring, an actual efficiency (&eegr;a) is calculated by applying a formula of Q×(P-Ps)×10/(3600×√3×V×I×&eegr;m×Pf) with an actual flow rate (Qa) and an actual lift (Ha), an expected efficiency (&eegr;e) is calculated by applying a formula (&eegr;e=Q×H×S.G×g/3600×B. H.P.), an actual efficiency (&eegr;a) and an expected efficiency (&eegr;e) are compared with each other to judge if an abnormal state is present or not.Internal leakage amount is calculated in reference to a comparison between initial values of flow rate (Qi) and head (Hi) and a comparison between actual measured values at the time of operation of actual flow rate (Qa) and actual head (Ha), and then an expected value of the wear ring clearance is attained in reference to the internal leakage amount. |
