Device and method for testing leakage rate of sealing ring gap of centrifugal pump impeller

The invention discloses a centrifugal pump impeller sealing ring gap leakage rate testing device and a testing method, which can realize the measurement of the gap leakage rate of a front sealing ring and a rear sealing ring on the premise of not changing the liquid flowing state of a front pump cavity, a rear pump cavity and a balance cavity, and the reliability of the testing result is extremely high. Meanwhile, the front sealing ring gap leakage rate testing unit and the rear sealing ring gap leakage rate testing unit are both connected with the centrifugal pump body in a closed loop mode, the whole testing device is totally closed and free of leakage, and the gap leakage rate of the front sealing ring and the rear sealing ring can be measured when the pump is in any flow working condition and cavitation state. Besides, the front and rear sealing ring gap leakage rate testing unit and the front and rear sealing ring gaps are independent systems, and if the leakage rates of the sealing ring gaps with differ