|
|
|
| Calculation method of contaminant intrusion flow rate induced by negative pressure events in water distribution system |
| YANG Yan1, ZHANG Tu-qiao1, LIU Wei-chao2 |
| 1. College of Civil Engineering and Architecture, Zhejiang University, Hangzhou 310027, China; 2. School of Civil Engineering, Shijiazhuang Tiedao University, Shijiazhuang 050043, China |
|
|
|
Abstract The orifice equation is typically used for calculating intrusion inflow volumes, which does not consider the properties of the porous media surrounding the pipe. An analytical relationship was derived by combining the one-dimensional seepage and the flow through an orifice for predicting the intrusion flow rate for a circular orifice under steady-state conditions. An experiment study was conducted to validate the accuracy of the analytical expression, and the analytical results fitted well with experimental results. Experimental results indicate that the presence of porous media could change the intrusion flow rate and add dependencies on the orifice size and permeability of porous media. The impact of the soil surrounding pipelines should be considered for calculation of intrusion flow rate.
|
|
Published: 10 September 2015
|
|
|
给水管网负压引起污染物入侵的流量计算方法
针对污染物入侵流量计算时常用的孔口公式未能考虑管道周围土体的问题,将多孔介质中的一维渗流与孔口出流相结合,推导了稳定流条件下圆孔破损的污染物入侵流量估算方法.通过模型试验验证了该计算方法的准确性,计算结果与试验结果吻合较好.试验结果表明,多孔介质的存在会改变孔口入侵流量,入侵流量与孔口大小及多孔介质的渗透特性有关,估算入侵流量时应当考虑管道周围土体的影响.
|
|
| ［1］ LECHEVALLIER M W, GULLICK R W, KARIM M. The potential for health risks from intrusion of contaminants into the distribution system from pressure transients ［EB/OL］. ［2010-10-21］. http:∥www.epa.gov/ogwdw/disinfection/tcr/pdfs/whitepaper_tcr_intrusion.pdf．
［2］ HOOPER S M, MOE C L, UBER J G, et al. Assessment of microbiological water quality after low pressure events in a distribution system ［C］∥ Proceedings of 8th Annual Water Distribution Systems Analysis Symposium. Cincinnati: ［s. n.］, 2006．
［3］ HUNTER P R, CHALMERS R M, HUGHES S, et al. Self-reported diarrhea in a control group: a strong association with reporting of low-pressure events in tap water ［J］. Clinical Infectious Diseases, 2005, 40(4): e32-e34．
［4］ GELDREICH E E, FOX K R, GOODRICH J A, et al. Searching for a water supply connection in the Cabool, Missouri disease outbreak of Escherichia coli O157∶H7 ［J］. Water Research, 1992, 26(8): 1127-1137．
［5］ PAYMENT P, RICHARDSON L, SIEMIATYCKI J, et al. Randomized trial to evaluate the risk of gastrointestinal disease due to consumption of drinking water meeting microbiological standards ［J］. American Journal of Public Health, 1991, 81: 703-708．
［6］ PAYMENT P, SIEMIATYCKI J, RICHARDSON L, et al. A prospective epidemiological study of gastrointestinal health effects due to consumption of drinking water ［J］. International Journal of Environmental Health Research, 1997, 7: 531．
［7］ HE X Q, CHENG L, ZHANG D Y, et al. First molecular detection of group a rotaviruses in drinking water sources in Beijing, China ［J］. Bull Environ Contam Toxicol, 2009, 83: 120-124．
［8］ BESNER M C, PRVOST M, REGLI S. Assessing the public health risk of microbial intrusion events in distribution systems: conceptual model, available data, and challenges ［J］. Water Research, 2011, 45: 961-979．
［9］ VAN ZYL J E, CLAYTON C R I. The effect of pressure on leakage in water distribution systems ［C］∥ The Institution of Civil Engineers-Water Management, 2007, 160(2): 109-114．
［10］ WALSKI T, BEZTS W, POSLUSZNY E T, et al. Modeling leakage reduction through pressure control ［J］. American Water Works Association Journal, 2006, 94(4): 147-155．
［11］ MCINNIS D. A relative-risk framework for evaluating transient pathogen intrusion in distribution systems ［J］. Urban Water Journal, 2004, 1(2): 113-127．
［12］ COLLINS R, BESNER M, BECK S, et al. Intrusion modeling and effect of groundwater conditions ［C］∥ Water Distribution System Analysis. Tucson: ［s. n.］, 2010: 585594．
［13］ COLLINS R, BOXALL J. The influence of ground conditions on intrusion flows through apertures in distribution pipes ［J］. Journal of Hydraulic Engineering, 2013, 139: 1052-1061．
［14］ MANSOUR-REZAEI S, NASER G H. Contaminant intrusion in water distribution systems: an ingress model ［C］ ∥ World Environmental and Water Resources Congress. Albuquerque: ［s. n.］, 2012: 3002-3010．
［15］ YANG Y, ZHANG T, ZHU D. Influence of porous media on intrusion rate into water distribution pipes ［J］. Journal of Water Supply: Research and Technology—AQUA, 2014, 63(1): 43-50．
［16］ EBACHER G, BESNER M C, CLMENT B, et al. Sensitivity analysis of some critical factors affecting simulated intrusion volumes during a low pressure transient event in a full-scale water distribution system ［J］. Water Research, 2012, 46: 4017-4030．
［17］ BORDIERA C, ZIMMER D. Drainage equations and non-Darcian modelling in coarse porous media or geosynthetic materials ［J］. Journal of Hydrology, 2000, 228(3/4): 174-187．
［18］ IZBASH S. Filtracii kropnozernstom materiale ［M］. Leningrad: USSR, 19-31．
［19］ VENKATARAMAN P, RAO P. Darcian, transitional, and turbulent flow through porous media ［J］. Journal of Hydraulic Engineering, 1998, 124(8): 840-846．
［20］ ZHANG Y, LIU W, SHAO W, et al. Experimental study on water permittivity of woven polypropylene geotextile under tension ［J］. Geotextiles and Geomembranes, 2013, 37: 10-15．
［21］ JTG E40—2007,公路土工试验规程［S］. 北京：人民交通出版社,2007．
［22］ 刘伟超. 土工织物管袋充填特性及计算理论研究［D］. 浙江: 浙江大学, 2012． |
|
Viewed |
|
|
|
Full text
|
|
|
|
|
Abstract
|
|
|
|
|
Cited |
|
|
|
|
| |
Shared |
|
|
|
|
| |
Discussed |
|
|
|
|
