一次风二次风（Primary air and two air）.docVIP

一次风二次风（Primary air and two air） Reduce the fluidizing air volume and reduce the wear of water wall Abstract: This paper analyzes the feasibility and necessity of reducing the flow rate of air flow to reduce the abrasion of water wall from one or two winds ratio, internal circulation material quantity and so on. Keywords: one or two wind ratio, internal circulation, material flow, air flow, abrasion At present, the water wall of circulating fluidized bed boiler in 135MW unit is seriously worn, especially the front wall. From January to the end of April, a total of 72 working days before the wall wear from 8mm to 6.8mm. The main reason for this severe wear is the excessive amount of fluidizing air flowing into the bottom air chamber. Here I will reduce the flow of air to reduce water wall wear, talk about my point of view: One, two winds ratio is not appropriate When the boiler operates at rated load, the air volume entering the bottom air chamber is 160000m3/h, and the two air volume is 90000 m3/h. At this time, the oxygen content in the flue gas is 2%~3%, and the ratio of the air rate of the one or two air is 64:36. Clearly, the 60:40 exceeds the design value. The apparent fluidizing wind speed is also above 7.8m/s. I plant the 135MW circulating fluidized bed boiler design coal ash from the base is 18.43%, received net calorific is 21.62MJ/Kg. And we are now burning coals from the base ash in about 10%, received net calorific in more than 22.154 MJ/Kg, the average monthly net calorific value as received basis in 24244MJ/Kg. This is clearly a quality coal, which burns fast and releases heat rapidly. This requires us to control the combustion share of dense phase region, the dense phase combustion in anoxic process in the combustion heat release can come in and new coal heating fluidized air, can be absorbed part of water wall and flue gas out of the dense phase zone, keep heat Ping Heng to maintain stable operation, the bed temperature within the prescribed scope. To