The Application Study Of Automatic Current Limiting Interceptor Intercept The Initial Rain Of Eco-city In Dongtan Chongming

The initial rainwater is the main part of urban pollutant sources.In the deeply urbanization area with the surface pollution load highly,it could cause serious damage for receiving water.Therefore,it is very important to deal with and utilize the rain water.As exceptional structure,automatic current limiting interceptor can be used for limit pollutant water and rain water.Meanwhile,automatic current limiting interceptor could keep surface retention unchanged.It also can avoid increasing the load of sewage treatment plant and ensure sewage channel.In order to predict the ability of automatic current limiting interceptor in the deeply urbanization area,and make full use of the capability of overall system,this thesis would target eco-city in Dongtan Chongming.Firstly research automatic current limiting system.Secondly analyze rainfall in the 30a.Finally establish a appropriate SWMM model and simulate runoff of automatic current limiting system to draw a conclusion of intercept effect of automatic current limiting interceptor for the initial rainwater.This thesis reaches follow conclusions:?1?According to the rainfall data from 1984 to 2013,eco-city in Dongtan Chongming precipitation change trend is not obvious,has a decreasing trend year by year.The average of annual rainfall is 1153.8 mm,maximum rainfall is 1568.0 mm,the smallest rainfall is 768.6 mm.?2?Based on the monthly average rainfall accounts for the proportion of annual precipitation from the year 1984 to 2013,rainfall time distribution mainly concentrates in March to September,is 76.37%of annual rainfall.The rainfall in June to August is the largest,accounting for 43.65%of the annual rainfall,and the less rainfall is in November to December,only 7.99%of annual rainfall.?3?In 1984 to 2013,average annual rainfall is 124d,92d with light rain,annual moderate rain more than 21d,8d the heavy rain,3d with heavy rains and above,most of the rainfall of the year for light rain and moderate rain.?4?Use SWMM generate the model accord with the actual situation of eco-city in Dongtan Chongming to study area of rainwater runoff simulation and debugging.The simulation results show that the impervious area manning coefficient of 0.011,permeable zone manning coefficient of 0.06,impervious area depression storage quantity of 1.5 mm,transparent water storage volume of 2.54 mm,maximum infiltration rate of 72.4 mm/h,minimum infiltration rate is 3.18 mm/h,take 2 h^-1 infiltration attenuation coefficient,the simulated runoff coefficient is 0.41,and meet the requirements of planning,accord with the actual case study area.?5?With studying the vortex flow-limiting valve as the main current limit automatically intercept facilities of different diameter on the pressure head-the influence of the flow curve,draw the conclusion:DN80,DN100 and DN150 suitable scope of work in the spiral flow metering valves are:1.75 to 4.00 L/s,3.50 to 7.00 L/s and 6.50 to 11.00 L/s.?6?In 2013 eco-city provided a total of 50 d rainfall runoff,the child 2 runoff catchment area is about 136890 m,Z1 north road Y55 intercept Wells river closure of the early rain amount is about 29290.86 m³,intercepting rate of 21.40%.The 12 months of intercepting rate up to 75.99%in November,a rainstorm occurred in June,July and October intercepting rate are low of 15.46%,11.60%and 4.62%respectively.?7?Once an eco-city Z1 north road 2013 Y55 intercept Wells in river closure of SS and COD were 4.63 t and 1.23 t.Z1 north road Y55 intercept well corresponds to the area of the catchment area 2 to 25 ha,the study area with a total area of 393.8 ha,SS and COD of the intercept system to the total research area of river closure amount is about 72.93 t and 72.93 t.Due to the eco-city is still in the early planning and construction,not a lot of human activities,SS and COD concentration is low,the long-term view,intercepting system of SS and COD closure quantity will increase,has the very good economic benefits.These methods and steps of this thesis would have meaning to feasibility research for the initial rainwater system.