Closed test device for NPSH of submersible pump

Abstract

The invention belongs to the technical field of fluid machinery, and particularly relates to a closed test device for the NPSH of a water-filling type submersible pump and a submersible pump for a well. The test device is composed of a cavitation tank, an inlet valve, a non-concentric diffusion tube, a suction tube, a submersible pump, a temperature meter, an inlet pressure gauge, a transition tube, a first seal joint, a revolution speed measurement instrument, an outlet pressure gauge, a water drainage tube, an outlet pressure measurement tube, a second seal joint, a flow meter upstream straight tube segment, an inlet pressure measurement tube, a revolution speed transducer, a flow meter, a flow meter downstream straight tube segment, a flow control valve, a water injection valve, a vacuum pump, a drainage valve, an exhaust tube, a partition plate, a liquid level meter, an extraction valve and a vent valve. The temperature meter, the inlet pressure gauge, the outlet pressure gauge, the revolution speed transducer, the revolution speed measurement instrument and the flow meter are used for measuring key parameters of the NPSH of the submersible pump. The test device has the advantages that the critical NPSH of the submersible pump under the conditions of different flows can be measured through the test device for the NPSH of the submersible pump, and the problem that a cavitation performance test of the submersible pump cannot be carried out is solved.

Description

technical field [0001] The invention belongs to the field of fluid machinery, and relates to a hydraulic performance test of a submersible pump, in particular to a closed test device capable of measuring the NPSH of a water-filled submersible pump and a well submersible pump. Background technique [0002] A submersible pump is a general-purpose machine widely used in industry, agriculture, and various engineering fields. Its structure is that the submersible motor and the water pump share a shaft. Unlike general land water pumps, the submersible pump has no suction pipe. [0003] The hydraulic performance index of the pump usually includes flow, head, shaft power, efficiency and NPSH, and NPSH is an indirect measurement, which must be calculated from the data of pump inlet pressure head, vaporization pressure head and other data. A large amount of data proves that cavitation damage is the direct culprit of water pump failure. Like other water pumps, submersible pumps often ...

AI Technical Summary

Problems solved by technology

Since the submersible pump has no suction pipe, the total suction head cannot be measured, and the standard does not provide a specific measurement method for the NPSH of the submersible pump

Another standard GB / T12785-2002 "Test Methods for Submersible Electric Pumps" also does not provide a test method for cavitation performance of submersible pumps, and no public reports have been found in other documents

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