Research On Energy Conservation Of Pneumatic Conveying System Of Road Sweeper

With the rapid development of cities in China and the deep promotion of urban civilization,the following problem is how to keep urban roads clean.Road sweepers are widely used in cleaning urban roads,whose dust absorption performance can generally meet the requirements of daily use.Exploring and improving energy consumption characteristics of pneumatic conveying system was studied in this thesis,in order to reduce the energy consumption of the core component(pneumatic conveying system)during cleaning the roads.The main work are as follows:The structure and operating principle of pneumatic conveying system were introduced.Then the interaction process between airflow and dust particles in the pneumatic conveying system was further clarified during cleaning the roads.And the process was shown authentically by using the coupling method of computational fluid dynamics and discrete element method,which provided effective technical means for subsequent simulation analysis.The calculation model of pneumatic conveying system and particle model were established.Based on the corresponding selection of collision contact model and the corresponding establishment of particle factory,the pneumatic conveying system was studied by using gas-solids coupling simulation.The results showed that there were unreasonable structures in the dust conveying device which aggravated the energy loss of pneumatic conveying system and extended its working time during cleaning the roads.It went against the energy conservation of the pneumatic conveying system.Single-factor coupled simulation tests(structural parameters of dust conveying device)were designed and carried out after the determination of the six test factors and two test indicators(energy loss?E_L and working time t).When the cleaning rate achieved the standard,with the variation of the six test factors,the variation tendency and optimum range of the two test indicators were analyzed.The research showed that the relationship between test factors and test indicators were complex,interrelated and inhibitory.Within a certain range,it was quite different that the structural parameters of the dust conveying device made effects on the energy consumption characteristics of pneumatic conveying system.So it was necessary to balance the influence of the dust conveying device's structural parameters,in order to reduce the energy consumption of the pneumatic conveying system.Multi-group central tests were designed and carried out of by using Response Surface Methodology.Based on the cleaning rate achieved the standard,two approximate models of the target response values(energy loss?E_L and working time t)were established,whose accuracy and error were in the acceptable range.Finally,the multi-objective optimization of the dust conveying device's structural parameters was carried out by the approximate models of two target response values.The optimization results showed that the reliability of the optimization model was high.Compared with the original model,energy loss?E_L and working time t of the pneumatic conveying system decreases by 27.78%and 7.77%.Therefore,without changing the cleaning performance of the road sweeper,the energy consumption of the pneumatic conveying system was obviously improved.Based on the cleaning rate achieved the constraint,gas-solids coupling simulation was applied in this thesis,in order to explore and balance the influence of the dust conveying device's structural parameters on energy conservation of the pneumatic conveying system,using Response Surface Methodology.It can provide guidance and powerful technical means for the research and design of the pneumatic conveying system's energy conservation.