Influence of Offset Terminal Elbow Shape on the Discharge Capacity of a High-Rise Building Drainage System
Publication: Journal of Pipeline Systems Engineering and Practice
Volume 14, Issue 4
Abstract
In practical engineering, it is common to offset the drainage system axis to avoid conflicts with beams and columns. However, such an offset could significantly affect the system’s discharge capacity and drainage safety, leading to a prominent positive pressure above the offset floor. To address this issue, we propose optimizing the system by changing the elbow shapes at the offset position. In our study, we conducted comparative experiments on three elbow shapes, namely, a normal 90° elbow, double 45° elbow, and large curvature elbow, in two experimental systems. Pressure fluctuation and water seal losses were used as experimental parameters to determine the maximum discharge capacity in accordance with the Standard for Capacity Test of Vertical Pipe of the Domestic Residential Drainage System. Our experimental results show that replacing the 90° elbow with the double 45° elbow slightly reduces positive pressure. On the other hand, using the large curvature elbow effectively increases the drainage flow and reduces the positive pressure caused by the upper floor bias. Furthermore, we employed computational fluid dynamics (CFD) software to simulate the flow of water and air in the system, demonstrating the benefits of increasing the elbow at the connecting position.
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Data Availability Statement
Some or all data, models, or code that support the findings of this study are available from the corresponding author upon reasonable request.
Acknowledgments
This research has been supported by the National Natural Science Foundation of China (Grant No. 51978536), the Fundamental Research Funds for the Central Universities (Grant No. 2042021kf0059), and the China Postdoctoral Science Foundation (Grant No. 2021M702529). The National Building Drainage Piping System Technology Center in Gaoping, Shanxi Province, China provided us massive support, including the experimental equipment and technical guidance. The SUNS Industrial Group provided the test materials needed.
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© 2023 American Society of Civil Engineers.
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Received: Mar 31, 2022
Accepted: Apr 18, 2023
Published online: Jun 24, 2023
Published in print: Nov 1, 2023
Discussion open until: Nov 24, 2023
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