High-power centrifugal pump hydraulic performance prediction method based on weak compressible flow analysis

Abstract

The invention provides a high-power centrifugal pump hydraulic performance prediction method based on weak compressible flow analysis. The method comprises the following steps that (1) a new sub-gridstress model is determined; (2) numerical calculation of a total flow field in a pump is carried out to obtain basic data of hydraulic performance prediction; and (3) the lift, the hydraulic efficiency and the net positive suction head are calculated according to the basic data of hydraulic performance prediction. According to the method, for the inner flow characteristic of a high-power highs-speed flow centrifugal pump and the defects of a dynamic sub-grid stress mode, the dynamic sub-grid mode with helicity constraints is constructed, the numerical simulation method of an in-pump weak compressible high-rotating-speed flow field is set up, and accurate numerical prediction of the hydraulic performance of the centrifugal pump is achieved.

Description

technical field [0001] The invention relates to a method for predicting hydraulic performance of a high-power centrifugal pump, in particular to a method for predicting hydraulic performance of a high-power centrifugal pump based on weakly compressible flow analysis. Background technique [0002] Centrifugal pumps are key equipment in the process fields of petrochemical, chemical, coal chemical, and pharmaceutical industries. They transport liquid working media under pressure to each production link and operating unit of the system, and are the heart of the entire liquid delivery system. The production process of petrochemical and other process industries is continuous large-scale production. As the key power equipment for fluid transportation, high-power high-speed process centrifugal pumps must have superior hydraulic performance indicators. [0003] The shortcomings of existing research mainly lie in: [0004] 1. There are not many in-depth studies on the specific calcul...

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Problems solved by technology

[0006] 3. There are not many studies on turbulence models; currently, there are turbulence models suitable for the calculation of internal flow of centrifugal pumps under full flow conditions, accurate calculation of internal flows under unstable operating conditions, characterization of internal flow instability, and internal The research on the influence of flow instability on external characteristics has not been carried out sufficiently, and a consensus has not been reached on the instability of centrifugal pumps, and no suitable unstable flow control method has been proposed.

However, since the model assumes that the sublattice stress is only proportional to the strain rate tensor, it is not well suited for rotational flow

Turbulence models have not been adequately validated for flow calculations in gaps

[0007] 4. There are not many studies on the numerical calculation of the full flow field; the internal structure of the centrifugal pump is complex, and in addition to the internal flow of the main flow field, there are also special flow phenomena such as gap flow and static and dynamic interference in the pump. The scale is relatively small compared to the main flow, but it has a great influence on the performance of the centrifugal pump, and in some cases even causes the centrifugal pump to fail

However, most of the current researches are carried out in the non-full flow field, and few studies include the full flow field;

[0008] 5. There are not many studies on hydraulic performance prediction of centrifugal pumps; the current research requires a lot of work and a large number of models need to be produced and the performance of the models measured

If the performance cannot meet the requirements, the model needs to be redesigned and experimented. The existing research has been unable to meet the requirements for the improvement of the hydraulic performance of the multi-stage centrifugal pump. Design is a research content that needs to be developed urgently

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