Performance Analysis And Optimization Of Double-suction Centrifugal Pump

Pump is an extremely widely applied general machinery. When there is fluid flowing, there is always a pump working. Centrifugal pump is the most widely used pump, which almost takes up 70 percentage of the total number of the pump equipment. Double-suction centrifugal pump is an important variety of centrifugal pump with high delivery head, large volume flow rate and easy to maintain. It becomes more and more popular in engineering. Therefore, understanding the internal flow field characteristics of the double-suction centrifugal pump, improving the structures and optimizing the fluid flow to improve efficiency are important and significant to promote the development of pump industry.In this paper, the three-dimensional model of OTS 125-500 A double-suction centrifugal pump is established. Five turbulence models, which are usually used in numerical simulation, are applied to calculate the performances of the pump. By comparing the numerical results and experimental ones, it can be found that there is a good consistency between numerical and experimental results, which indicates the results obtained by numerical simulation are reliable. At the design point, due to the minor error values, five turbulent models’ results are ideal. Considering the head and efficiency performance parameters, at low flow rates, Realizable k-ε turbulence model is better; at high flow rates, SST k-ω turbulence model is more excellent.By observing the internal flow state under different operating conditions and analyzing the distributions of static pressure, velocity magnitude and turbulent kinetic energy, the internal flow regularity of the double-suction centrifugal pump is found. The results show that there exists “jet-wake” in the impeller. Due to the interference of the volute tongue, the flux takes place in the volute, which results in large energy lost. This phenomenon makes efficiency lower.According to the numerical simulation results, without changing the structures, the deflector is placed in the volute channel to realize the optimization of the flow field in the double-suction centrifugal pump. By exchanging the shape, quantity and position of the deflector, it is found that the curved deflector is more suitable to the centrifugal pump flow field. Since the throat channel of the pump is relatively narrow, taking efficiency and other performance parameters into consideration, the author ultimately determine only one deflector is adopted. After several simulations, the results with the deflector mounted in the middle upper 1/3 position is the best. It can both inhibit the formation of the flux and improve the efficiency of the double-suction centrifugal pump.