Study On Feculence-blocking And Feculence-clearing For Pump Station

For the non-uniform of the water resources in space and time, to satisfy the demand of industrial and agricultural producing and people living, many large water transfer projects have been constructed in our country. And in the water transfer projects pump stations are the heart parts. In China, the total installed capacity of pump stations is over 70,000 MW. Because of long operation time and large installed power, operating safely and economically is significant to lowering cost. Main works in this dissertation are as follows:The structural style, the operating principle and the trash-clearing mode of the trash rack are introduced. According to the present state of the research and the problem in the application of the trash rack, the influences of the trash rack on the operation of the pump units are analyzed, and the failure reasons of the trash rack are pointed out. By analyzing the clearing effect and the safety of the trash rack of different structural, it can be got that the structural style and arrangement style of the trash rack should chosen appropriately according different working condition. Take Jiangdu pump station for example, by computing, the optimum clearing periodicity and corresponding operation cost of the conditions with different accumulate speeds of the trash. The computing data can be referenced for the application of the trash rack.The study data indicate that the operation condition of the trash rack influences the safety and efficiency of the pump units. The accumulation of the trash, on one hand will hold the channel up, which will reduce the cross-section area and increase the head loss, on the other hand, the trash accumulation before the trash rack will raise the head loss and reduce the working head. So the trash accumulation will at last reduce the operational efficiency of the pump station. To ensure the pump station efficiency, the pump station should choose the trash rack and trash-cleaning mode by the actual condition of it, and compute the optimum periodicity according to the trash-accumulating velocity and trash-clearing velocity.Main creative points in the dissertation are as follows:1. Removing the sewage on the trash rack is done on the promise that the electrical cost of pump station is the least. And the model of feculence-clearing are sorted.2. Feculence-clearing optimal computation is based on the variations of the discharge of sewage and the velocity of feculence-clearing.