Research About Hong Wei Power Station 410t/h Coal Fired Boiler Burning Residue Problem

The problem of coal fired boiler burning residue is common in many power plants. It is also unsolved critical problem for safe,economical and stable operation of power plants. During the last decades, this problem caused countless accidents in domestic power plants, they resulted in equipment damages, personal injuries or death, and even enomorous econoimic lose.Theoretically, this paper analyzes the cuases of boiler burning residual, and shows its adverse influences on boiler operation. Since its complexity of the problem, this problem has not been solved effectively so far. Severe accidents are still repeatedly seen in domestic made generator sets, even in imported sets. For an coal fired power plant, this problem is still making troubles threatening power plant safety, economics and reliability; with the increase of generator set capacity, this problem is becoming more and more prominent.Tests and analyses performed by experts and technical personnels show that, the brown coal used by Hongwei power plant is extremly prone to produce reside in the process of power generation.This paper discusses the problem of burning residue in the coal fired boiler 410t/h of Hongwei heat&power plant. It also presents some experiments of coal characteristics, tempreature behavior inside the boiler and its aerodynamic behavior. These results show that since the existent defects of combustion device structure and its hypothetical circle of contact, these make a poor primary and secondary wind rigidity in operation and a too big actual circle of contact. In addition, the coal used is extreme prone to burn and reside in boiler. Under such a condition, the coal powder ignites earlier in a short time and short distance when it leave the jet-combustioning device, and splashes the water cooler, eventually this results in a burned coal residue in boiler. On the basis on these study results, we suggested some technical measures to reduce the coal residue in boiler to ensure a safe and economic operation of the generator set. These measures are as follows: shorten the primary wind intervals to improve thermal load of the burner; reduce the size of hypothetical circle of contact to prevent the flame from splashing; use nozzles with larger height/width ratio to increase the effusive rigidity, so as to increase the jet flow depth of secondary wind into the main jet flow; use a higher primary wind velocity to increase its jet flow rigidity; use a special flame holder structure of the primary nozzle, so as to improve...