Simulation Study On The Outlet Of Siphonic Roof Drainage System

Siphonic roof drainage system(SRDS) has higher displacement efficiency, less material consumption and the horizontal hanging pipe is conducive to mechanical and electrical pipeline comprehensive arrangement, compared with the traditional gravity flow of rainwater system, particularly suitable for large construction roof.However,there are fewer publicly reported studies of siphonic rainwater head, the manufacturer of the siphonic rainwater head often treat the characteristics of the product as trade secrets and technology advantage to be confidential. The product quality of a variety of siphon rainwater head on the market are good and bad intermingled.FLUENT,the representative software of CFD, has strong ability of simulation,with large range of simulation and strongly practicability. The author take the FLUENT software as test platform, simulation studies siphonic roof rainwater drainage system. In this article, mainly research is focused on the siphonic rainwater head, for helpful to the improvement of the preliminary exploration of siphonic rainwater hopper.At first, the author introduced the work principle of siphonic roof rainwater drainage system,the research status and its development at home and abroad,as well as the knowledge of theory and operation steps of FLUENT software.Then, tested how riser height effect the maximum capacity of the siphonic roof rainwater drainage system,using FLUENT software simulation. The results show that the system’s maximum capacity increases with increasing along with the height of the riser, and the other specific information of the results matching the system working principle, flow of the actual situation and the existing research results closely. It proves that the simulate research,using FLUENT software,to the siphonic roof rainwater drainage system is feasible and reliable,and the result is credible. Lastly, the author used the FLUENT software to simulate research siphon rainwater outlet. After refer to some relevant specification atlas and product information,the author constructed three different shapes of the bucket body model of the system,to study how the shape of rainwater hopper affect its drainage capacity. At first, take the test flow as single factor variable to observes the drainage performance of the three siphonic roof rainwater drainage systems respectively. The result shows that, even though the biggest siphonic drainage ability of three build systems all in 9 L/s or so, but the siphonic rainwater hopper with shape of the funnel optimal performance, the performance of the cylindrical siphonic rainwater head second with, and the disc shape siphonic rainwater head work worst. then, keep water depth above the outlets is 200 mm, to make the system reached steady state of maximum siphon drainage flow, The calculation results proved the conclusion again. Then, researched how the height of anti-vortex plate affect the siphonic outlet’s drainage capacity.Take the disc shape siphonic rainwater head system as test object, the height of anti-vortex plate as single factor variables, to study the drainage of siphonic roof drainage system. The result shows that the best height of anti-vortex plate would be 30 mm.