Finite Element Analysis and Research on Force of Centrifugal Pump
July 24, 2023
Abstract: This paper uses the large-scale modeling software Pro / E to establish the shell model of the centrifugal pump that is widely used in the domestic petrochemical industry. Analysis software Ansys were used to carry out finite element analysis of several working conditions respectively. The standards of the API 610 of the American Petroleum Institute regarding the allowable force of a centrifugal pump nozzle were studied, and the relationship between the load and the control value and the relationship between the load value gain. Author: Wendel Ultra 2 1 Pancheng Yun Zhao Ji Tong cold 1 (1 Beijing University of Chemical Technology Mechanical and Electrical Engineering, Beijing 100029, China; 2 Beijing Petrochemical Engineering Construction Corporation Beijing 100101, China) 1 1. Introduction is a pump in the chemical and petrochemical industries more Common and important device. Reasonable and correct design of production in the production of centrifugal pumps is very important. Some design institute in the petrochemical industry found that the actual load of the centrifugal pump nozzle force in the practice of calculating the force exerted by the centrifugal pump nozzle is the same as the allowable nozzle load given in American Petroleum Institute (API) 610 standard Times or even ten times, still meet the requirements, normal operation. In the API610 standard of American Petroleum Institute, in order to ensure that the pump body subjected to the static and dynamic load and nozzle flange bolts and other external forces and torque, the pump and the prime mover axis consistent measured at the shaft coupling in any direction Displacement shall not exceed 0.127mm (0.005in) giving the maximum allowable load on the nozzle. In this paper, the influence of the deformation of the pump body caused by the nozzle on the shaft end, ie the shaft displacement at the coupling, is studied. In this paper, a three-dimensional model of a single-stage single-suction cantilever centrifugal pump was set up with Pro / E, the grid was divided and output to the analysis software Ansys, imposed constraints, coupled with allowable load in the API610 standard And based on its several load conditions, after the finite element calculation has been analyzed, and reached certain conclusions for reference in engineering practice, also verified the above-mentioned project actual situation. 2. Geometry and Finite Element Modeling 2.1 Model Simplification Pro / Engineer from PTC is a powerful 3D modeling software. It is used in this paper to build a centrifugal pump model. The overall structure of the pump assembly, simplified as follows. Axis does not consider the impeller components, and its impact on the structure; shaft coupling, regardless of the coupling and its impact on the pump components; support does not consider the base and its operating conditions may be in a variety of The impact of the pump assembly; various loads at the inlet and outlet flanges and tightening torques of the flange bolts, etc. The effect of components other than the pump assembly on the pump is reduced to a combination of force and torque applied to the flange surface of the pump . The pump housing (front cover, rear cover, flange import and export takeover and import and export flanges) complex structure, a lot of curves and surfaces, the shape and size of many different parts, in order to avoid simplification to bring too much accuracy, so There is not much simplification in modeling. Pump components to simplify the parts are: Shaft, the shaft to remove some of the shoulder, collar, thrust journals and keyways, the shaft becomes a shaft with only four different shaft diameters; bearing, omitting the inner ring, The outer ring, rolling body, cage and other detailed structure will be seen as a hollow cylinder. The model shown in Figure 1. 2.2 division unit using free grid, local encryption. The unit used is a 10-node tetrahedron physical unit. 3. Constraints and Load Analysis 3.1 Constraints Pump casing support is usually divided into centerline support and end or foot support and other types. Single-stage or two-stage cantilever centrifugal pumps generally have only two symmetrical bracing. The pump is a single-stage centrifugal pump, the pump is placed on both sides of the support base on the base, and with two pairs of bolts. According to the actual installation and support of the pump, to simplify, the constraints are as follows. In the coordinate system of the model above (+ Z axis in the downward direction and + X axis to the left), the Z-direction displacement is 0 on the bottom surface of the support platforms on both sides; in the four bolt holes Inside, X and Y displacements are zero. 3.2 load analysis 3.3 simplified load pump is mainly through the import and export of flanges and other components such as pipes connected to other parts to its role mainly by the flange between the two bolts to pass to the pump body. According to the actual situation, the rules of load or irregular distribution of the pump inlet and outlet flange. In this paper, for the convenience of calculation, after taking full account of the load distribution, the above load is further simplified to consider the position of the bolt hole centerline on the flange surface. Based on the load checked in the standard, add 2 times, 3 times to 10 times of the reference load, calculate and analyze. The load conditions and their results will be introduced below. 4. Calculation results The final test is the displacement of the right side of the spindle shown in the figure above, the displacement obtained below the cloud and the numerical results are here. Take the shaft edge of the outer edge of the path.
