Analyse Of Hydrodynamic Of Hydraulic Controlling Ditch In Initial Rainwater Collection Devices

As the progress of urbanization and the development of GDP, the lack of water resources and water environment pollution turns more and more serious. Currently, the recycling of rainwater has become an important study direction in the water resource utilization and protection. The recycling of rainwater makes great sense in improving urban ecological environment and promoting the sustainable development of urban water resources and water environment.The water quality and water quantity of surface water drain present strong random change characteristics with the influence of randomicity of precipitation, uncertainty of surface pollution sediment, complexity of physiognomy and hydrological characteristics. The current rainwater collection devices or systems have a low efficient of collecting the clean rainwater and can not avoid the unsafety and low reliability of rainwater in the initial period, which badly restricts the development and popularization of the recycling technic of rainwater. The reason lies in that these devices and systems have no tracking and controlling of the random change process of rainwater quality, and cannot actually determine the time period of initial rainwater and avoid it. Therefore, there are serious problem of collecting pollutants of high concentration into the rainwater storage pool and pollute large amount of recyclable clean rainwater.Based on reference reading, local experiment and hydrodynamics analysis of rainwater drain, this thesis analyzed the characteristics of random fluctuation of the pollutant concentration in the rainwater drain and the distinct of the initial increasing and anaphase decreasing of pollutant concentration. Through experiment, the uncertainty of the pollution of surface drain and the relativity of COD and SS changes are studied. A rectangle water controlling ditch and initial rainwater discarding device are set up, which makes the hydrodynamics analysis of the rainwater controlling ditch and the analysis of discrete case of pollution controllable. The discrete controlling function of pollutants in the rainwater controlling ditch and the Saint-Venant equation set of hydrodynamics controlling function of rainwater motion are established, furthermore, the transfer process of rainwater pollutants in the controlling ditch is analyzed, and the controlling program is worked out, with which, the opening and closing process of initial rainwater discarding device is controlled.This device brought up in this thesis solved the problem in the collection of rainwater in our country that the collecting efficient is low and the safety in collection is bad. This provided a reliable technic support in the recycling of rainwater and solution of water resource shortage, which has a great social and economical benefit.