Numerical Simulation And Analysis Of Flow Field In Double Suction Impeller And Volute Of Low Specific Speed Centrifugal Pump

Petrol-chemical process pump is very important in the chemical process, which affects the normal running of the chemical enterprise. With the development of chemical industries, people advanced new and high requests, requesting the pump running continuously in long period and safely. Presently, Petrol-chemical process pump is developing to large scale and high speed. Based on this thought, people design the HD type petrol-chemical process pump. The design is very novelty, the structure is compact, the performance parameter is different to other pumps. It can transport mordant liquid, high temperature liquid, flammability liquid, poisonous liquid and the liquid without solid grain. It can be used in the Petrol-chemical enterprises, oil refining enterprises, chemical products enterprises, and so on.To make the HD type petrol-chemical pump have better performance, It is very important to know about the flowing distributions. There are two study means: experiment and numerical simulation. Experiment is the most direct, but the investment is very large, the period is very long. The nicety and precision of the data are limited by the testing instruments and environment. The analyzing ability on the flowing fields and the remote flow structures will also be restricted. With the development of computer technology fast, the consummation of numeration model and technology of numeration, people attach importance to using the CFD software to simulate the flow field.In this paper, the developing station of centrifugal pump all over the world are analyzed and concluded;the theory of CFD and mathematics model are studied;the entity model of HD type petrol-chemical pump is generated and meshed;the inner flow of HD type centrifugal pump is simulated and analyzed by the software of Fluent, the distribution of different inner stress and velocity at different stations are studied, such as design flow, high flow and low flow. Some important flow phenomena are caught:1. There is low pressure near the vane inlet, and the low pressure is more visible. This low pressure will make cavitation damage to the pump.2. There is wake flow on the vane outlet, the area of wake flow ties up with the flux.3. On the converge point of double vane, the velocity and pressure appear fluctuation .As the flux augment, the fluctuation becomes obvious.4. With the flux augment, the pressure difference between pressure face and suctionface will minish.5. The distribution of pressure in double volute is symmetry 180°, there is refluence on the tongue, there are also refluence and strike in the channel, the flux is different ,the degree of them are different.After analyzing the phenomena in a detailed way, we find there is unreasonable area in the design of volute. The datum offer reliable information to improve the pump' performance and the type of vanes and volute. The results proved that the simulation results of transporting the pure water by CFD software of Fluent can agree with the experiment data basically, simulating the inner flow field of HD type petrol-chemical pump by Fluent is reliable.