Research Of Test And Calculation Of The Pressure Characteristics Of The Pump Chamber And The Balance Chamber In Centrifugal Pump

The size of axial force in the range of balanced cavity has a decisive influence on balance effect of the axial force of the whole machine in centrifugal pump with opening balance hole and double sealing ring. This project is supported by the National Natural Science Foundation of China(51269010) the natural science foundation of Zhejiang province(LY12E09002). Made thorough researches on the liquid pressure distribution characteristics of pump chamber and the balance chamber,as well as the influence of the balance chamber liquid pressure on axial force with experimental measurement, theoretical analysis and numerical calculation in different condition of back sealing ring diameter and balance holes. The main contents of this paper are as follows:1. In order to research the distribution characteristics of the liquid pressure in the cavity and the balance cavity of the pump,take the IS80-50-315 pump as a model.Flow rate, pump cavity pressure point of the liquid pressure, rotational speed, input shaft power and other important parameters were collected when the pump under different working conditions and working steadily with specialized test equipment and measuring equipment. The results showed that different parameters have little effect on the performance of centrifugal pump. The liquid pressure of the pressure measuring point decreases with the increase of the flow rate, and increases with the increase of the radius of the measuring point. The pressure in the pump cavity has a tendency to decrease in a small range with the increase of the diameter of the balance hole. The different condition of increments of the back sealing ring diameter and balance hole diameter has influence of liquid pressure on the balance cavity was obvious, but has little effect the liquid pressure distribution of the front and back cavity.2. The diameter of the front sealing ring of the impeller is 90 mm and the clearance between the front and the back seal ring is unchanged, replace the diameter of 90, 105,115, 125, 140 mm impeller back seal ring with the diameter of 0, 4, 6, 8, 11 mm balance hole. The results showed that the liquid pressure of the balance chamber increases with the increase of the diameter of the back sealing ring, and the curve of the relationship is almost a number of oblique line under the same balance hole diameter. The liquid pressure in the balance cavity is obviously decreased with the increase of the diameter of the balance hole under the same diameter impeller back sealing ring. And showed that increasing the balance hole diameter has the effect of balancing the axial force.3. In order to study the characteristics of the liquid pressure of the pump cavity and the balance cavity in similar pumps, specific area and pressure coefficient havebeen introduced. In order to theoretical calculation of internal pressure of model pump,the calculation model has constructed and the test results analyzed by non-dimensional.The balance cavity internal liquid pressure dimensionless curves have been drawn and analyzed, the result showed that the theoretical calculation results are close to the experimental results for pump chamber pressure. For the fluid pressure of balance chamber, increase the diameter of the balance hole, so that the ratio of the area increases, and the pressure coefficient of the equilibrium cavity decreases, with the same back sealing ring. On the contrary, the ratio of the area was decreased and the pressure coefficient was increased. The curves from the theoretical calculation are close to the experimental results under design conditions, the calculation method was verified.4. With the numerical calculation models about the whole flow passage of the model pump, the relationship between the liquid pressure of the pump chamber and the balance chamber and the diameter of the sealing ring and the diameter of the balance hole were analyzed, and effect of the flow of centrifugal pump. The numerical results has been non dimensional analyzed and compared with the test value and the results showed that the error of balance cavity liquid pressure dimensionless curves were small and the accuracy of numerical simulation was proved. The flat zone of liquid pressure of balance cavity dimensionless curve can be used as the theoretical basis for selecting the diameter of the balance hole from the angle of improving the volumetric efficiency of the axial force.