Study On Drainage Pollution Control Of Yangbajing Geothermal Power Plant

On abroad, geothermal water is often reinjected into the terrestial heat field in order to extend the life of the terrestial heat field and reduce its' pollution to the aquatic environment after electicity-generating and then synthetical utilization. However, the used geothermal water of Yan Bajing has been and will be directly drained into the receiving water body桪ui Long river for a long time, for the absence of the safe and reliable reinject technology.Through studying the impact of Yangbajing geothermal water on Dui Long river, the writer finds that F~ ^ As and CODCr are the main pollutants which impact the water quality of the receiving river over 90km distance. Based on water quality monitor and hydrology monitor, this thesis analyzes the rules that geothermal water impacts on Dui Long river. With the help of the model on water quality, the rules of geothermal water pollution is studied by numerical simulation method. A conclusion that both of them fit together is obtained by comparing and analyzing the simulating results and the monitoring results.During the process of determining the value of parameters in the water quality model, writer explores the use of GA(genetic Algorithms) in numerical optimization and proves its advantages in the thesis, such as it's simplicity and readily feasibility, validity and universal application when GA is used to solve optimization problems in many peaks, multidimensional,nonlinear and discrete affairs. The actual application in this thesis shows that GA used to determine the parameters in the water quality model provides satisfying results.The section-ending control method and section-beginning control method are discussed in this thesis. Using water quality model and hydrology condition results, writer calculates the water enviroment capacity of several typical years (p=50%, p=75%, p=90% )under the aquatic enviroment target, presents the geothermal water pollution control project systematically, and produces some valuable guidance which can be used to direct the exploitation of geothermal resource in other areas and provide a new idea to protect aquatic environment.