Rational Design of a Pump-Sump and Its Model Testing

• Published in: Journal of pipeline systems 2011-05, Vol.2 (2), p.53-63
• Main Authors: Ahmad, Z, Jain, B, Kumar, S, Mittal, M. K
• Format: Article
• Language: English
• Subjects: Computational fluid dynamics; Cooling; Fluid flow; Operational problems; Pumps; TECHNICAL PAPERS; Turbulence; Turbulent flow; Vortices
• ISSN: 1949-1190; 1949-1204
• DOI: 10.1061/(ASCE)PS.1949-1204.0000074

Water pumps used in pumped storage plant, drainage, agriculture, and industrial process experience operational problems such as vibration, impeller damage, and wear of bearing caused by nonaxial inflow of water in the suction pipe. Rational design of pump-sump and vortex breaker aligns the nonaxial flow in the axial direction and reduces these operational problems in the pump. This paper deals with state-of-the-art-design of a pump-sump and the criteria for its model testing. A 1∶10 scaled model of a pump-sump with five cooling water pumps and three auxiliary cooling water pumps was tested, and the model results related to separation of flow, dead zones, surface and subsurface vortices, swirl angle, etc., are reported in this paper. No surface vortices were observed in any of the tests; however, Type-2 (dye core) subsurface vortices and a swirl angle that is more than the permissible value were noticed in most of the tests without vortex breaker. A conical vortex breaker with eight fins was very effective in reducing the swirl angle. Tests conducted at higher Froude numbers and velocity ratios for different combinations of pumps and water surface levels indicate a minor increase in the swirl angle, which is mainly attributed to high turbulence rather than the swirl in the flow.