Study of the Effects of Blockage and Impeller Fault in Centrifugal Pump using CFD Simulation

Abstract

Centrifugal pumps have been used as a vital component in most of the industrial applications aiding the way for liquid transport in various sectors ranging from the construction, manufacturing, hydropower, wastewater treatments to petrochemicals. The efficient and reliable operation of these pumps is very much crucial for any industry. However, the pumps are prone to various faults and defects during their life cycle which arises the necessity for addressing certain diagnostic tools for early fault detections and preventions. For these pumps to operate efficiently, it is very much important to understand the intricate dynamics inside the pump. This paper investigates the use of the open-source software OpenFOAM as one of the tools used in Computational Fluid Dynamics for studying the flow field inside the centrifugal pump. Steady-state simulations are performed using the simpleFoam solver via the MRF approach while the unsteady transient simulations are performed using pimpleFoam solver via the Sliding Mesh approach. A CFD model of Oberdorfer 60P pump have been developed to simulate the fluid flow pattern inside the centrifugal pump. The study mainly focuses on assessing critical pump parameters such as flow rate, head, pressure distribution, forces and torques characteristics. The flow field inside the pump are visualized using the ParaView utility of the OpenFOAM. The velocity vectors, static pressure across the domain is plotted and shown. The presence of blockage in the centrifugal pump results in the decrement of the static pressure near the inlet region thus increasing the change in static pressure across the fluid domain. The maximum flow velocity near the outlet section of the pipe gets reduced which results in the decrement of the discharge at the outlet. The presence of crack reduces the static pressure in overall domain. With increase in crack depth the static pressure decreases risking to the occurrence of cavitations. These results conclude that monitoring variation in pump parameters such as flow velocity and static pressure in the pump domain helps in developing an efficient methodology for fault detection and diagnosis system.