Articles written in Sadhana
Volume 46 All articles Published: 18 June 2021 Article ID 0123
Electric submersible pumps (ESP) are widely used in agricultural fields, petroleum and various other industries. These pumps are designed to operate under a wide range of head and discharge. Several failures of ESP are due to vibration. Since the rotating components of ESP run at a high-speed, vibration of elements ofESP is unavoidable. The scope of this present study is to conduct a modal analysis on a diffuser return channel assembly of a five stage ESP which delivers 7 lps and produces a total head of 60 m (rated at 50 Hz) to determinethe eigen frequencies and eigen vectors using finite element technique. The diffuser casing has six vanes and six return channel vanes with wall thickness, outer diameter and height values of 3.5 mm, 134 mm and 50 mm,respectively. A three-dimensional model of the diffuser casing is generated using laser scanning technique. Two different kind of constraints are applied and the modal characteristics of the diffuser casing were extracted by applying two different boundary conditions. The results have shown that the eigen frequencies are different from the pump operating speed by 76.91% and 96.10 % respectively in both of the two cases. The maximum value of displacement vector sum in Case 1 is found to be 5.70 mm and it is 15.89 mm in Case 2. The results obtainedfrom the eigen frequency analysis can be used to evaluate the problems caused by structural as well as flow induced vibration and to improve the operational reliability of pump casing.