Research On Design And Optimization Of Dry-Method Dust Emission System And Comprehensive Application Of Dry Ash

Dry emission of dry ash is the important problem to be solved by the newly founded or broadened power stations. It can decrease the land area of ash dams, the amount of water for flushing ash, and water pollution. Meanwhile, the collected dry fine coal ash can be applied comprehensively. Shaoyang Heat and Power Plant is a middle-or-small-sized heat and power enterprise set up in the end of the 80s, with two air-extracting and back-pressing steam turbines, one steam-condensing steam turbine, and three boilers, two of which are working and one is ready for operation. The total capacity of the plant is 30MW; the heat burden is steady; and wet ash emission method is adopted. The efficiency of dust emission is about 90%, which can't meet the demand of environmental protection. At the same time, the ash dam has reached the designed height, and can't meet the demand of ash emission. Dry dust emission system should be set up to decrease the amount of ash emission by ash dams. Through the study on the use of fine coal ash, the handling approaches of fine coal ash have been found.On the basis of the above analysis, the paper points out that the fine coal ash produced by Shaoyang Heat and Power Plant can meet the demand of producing cement in quality, and can be made full use of in number. The author has carefully computed and designed the dry dust emission system and negative-pressure-air -conveying system, reformed the former dust emission system and smoke path system, and transformed the previous one level water film dust emission to two level dust emission of dry and wet. All of these will improve the efficiency of dust emission. The system design is based on Shaoyang Heat and Power plant's land situation and economic effect. The system will occupy less land, need less investment, and have higher quality-price rate. In choosing the sizes of main equipments, the full use of ripe technique for reliability and economy has been employed. Learning from large-sized power plants'dry emission systems of dry ash, the paper has advanced approaches and suggestions of making use of advanced technology to optimize the system if economic condition permitting.The foundation of the system will offer experiences for the dust emission of small-sized thermal power plants, heat and power plants, and self-service power plants. It can solve the problems of ash emission and environmental protection with less investment, and have good prospect to spread.