CFD Technique for Solving Low Water Level Problem of Axial Flow Pumps
Sami Abdel-Fattah Abdel-Ghani El-Shaikh
Issue:
Volume 3, Issue 3, May 2017
Pages:
34-44
Received:
5 July 2017
Accepted:
21 July 2017
Published:
12 September 2017
Abstract: In this paper, water levels variation in the sump intake is studied in El- SHABAB Pumping Station. ANSYS Ver.17.1 flow simulation software is used to simulate the flow conditions to overcome decreasing water level in the low demands period, winter closure. Seven scenarios are studied to obtain the best one to apply it at that condition. Case 1 represents the optimum design when the submergence water level is 5m above the sump floor and the length of submersed part in the sump is 3.5m. Case 2 represents the winter closure period where the submergence water level decreased by 1.5m to become 3.5m in the period winter closure and the length of submersed part in the sump is 2m. As a result, velocity in the suction pipe decreased 26%, a swirl angle 10.79° is attained, and vibration level increased 4 times representing hydraulic and dynamic problems. Case 3 is done by adding a joint with length 0.5m to the submersed part of pipe. Case 4 is done by increasing a joint length by 1m to the submersed part of pipe. Case 5 is done by adding a cone under the bell mouse with height 1m and with the same pipe diameter. Case 6 is done by adding a cone under the bell mouse with height 1m and 0.5m joint leading to increase the submersed part of pipe to become 2.5m. Case 7 is done by repeating case 6 with increasing water submerging level after finishing the period of winter closure where the water level in the sump is 5m. The results indicate that, during the period of winter closure, Case 6 is the best condition to use where it prevents vortex and has the best swirling angle 5.12° with no turbulence is observed at the entrance of the pump improving the dynamic and hydraulic performance of the pump. Also, the results indicate that Case 7 after finishing the period of winter closure and water level returned to become 5m (optimum design) is the best condition to use during all seasons where it prevents vortex and has the best swirling angle 4.66°.
Abstract: In this paper, water levels variation in the sump intake is studied in El- SHABAB Pumping Station. ANSYS Ver.17.1 flow simulation software is used to simulate the flow conditions to overcome decreasing water level in the low demands period, winter closure. Seven scenarios are studied to obtain the best one to apply it at that condition. Case 1 repr...
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