LNG multi-stage immersed pump

Abstract

The invention relates to the field of centrifugal pumps. According to the technical scheme, an LNG multi-stage immersed pump comprises a front section pump shell, a middle section pump shell, a rear section pump shell, a bearing assembly, a built-in motor, a pump shaft, an inducer, a plurality of impellers, a plurality of guide vanes and a balance disc, wherein the front section pump shell, the middle section pump shell and the rear section pump shell are arranged sequentially from front to back, the front section pump shell is fixedly connected with the middle section pump shell, and the middle section pump shell is fixedly connected with the rear section pump shell; the bearing assembly is fixed in the front section pump shell; the built-in motor is fixed in the rear section pump shell;one end of the pump shaft is supported by the bearing assembly, and the other end of the pump shaft is fixedly connected with a motor shaft of the built-in motor; the inducer is arranged in the frontsection pump shell and fixedly connected with the front end of the pump shaft; the plurality of impellers are arranged in the middle section pump shell; the plurality of guide vanes sleeve the impellers, and the outer edges of the plurality of guide vanes are fixedly connected with the inner wall of the middle section pump shell; and the balance disc is installed on the pump shaft and fixed on therear side of the last stage impeller to balance the axial force of the impellers. The immersed pump can work in a low-temperature environment, the positioning problem of the impellers can be effectively solved, the circumferential and axial displacements of the impellers are avoided, meanwhile, the axial force at the two ends of the impellers is mutually balanced, so that the stable operation ofthe impellers is guaranteed, and the overall performance of the pump is improved.

Description

technical field [0001] The invention relates to the field of centrifugal pumps, in particular to an LNG multistage submersible pump. Background technique [0002] LNG is the abbreviation of liquefied natural gas (liquefied natural gas), the main component is methane. LNG is colorless, odorless, non-toxic and non-corrosive, and its volume is about 1 / 600 of the volume of the same amount of gaseous natural gas. Therefore, liquefied natural gas is an effective way of storage and transportation of natural gas, which has been developed rapidly in recent years. During the transshipment and filling process of liquefied natural gas, a large number of LNG submersible pumps are required. Among them, the impeller is the core component of the pump, and the positioning accuracy of the impeller can directly affect the overall performance of the pump. [0003] The main method of positioning the general impeller on the shaft is through the shaft shoulder and thread positioning. One side o...

AI Technical Summary

Problems solved by technology

However, at the beginning of the design, there is a margin for impeller adjustment between the snap ring and the axial clearance. When the multi-stage impeller is working, the axial force generated will cause the shaft sleeve and the snap ring to slip axially, causing the pump to run unstable

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