燃煤锅炉正压直吹式制粉系统温度分段控制

Temperature independent control for direct-firing pulverizing system

介绍了一种燃煤锅炉节能、安全新技术——正压直吹式制粉系统温度分段控制技术.该技术通过设置磨煤机热风旁路,分段控制磨煤机出口温度与粉管温度,使得磨煤机出口温度达到70℃,粉管温度达到100～120℃.采用该技术后：磨煤机冷风掺入量减少,锅炉排烟温度降低6～10℃,节能效果良好;可满足磨制高挥发分烟煤时磨煤机内部防自燃、防爆炸和粉管煤粉输送等安全性的要求;低负荷时提高粉管风速,控制磨煤机入口温度.该技术可在采用中速磨煤机和双进双出钢球磨煤机的正压直吹式制粉系统中应用,具有较大的应用前景.

A new energy saving and safety control technology for coal-fired boiler,temperature independent control for direct-firing pulverizing system, was introduced. In this technology, the hot air bypass of pulver- izer is designed to independently control the pulverizer＇s outlet temperature and pulverized-coal piping tem- perature,thus the pulverized-coal piping temperature can be controlled within range from 100 ℃ to 120 ℃, which is higher than the pulverizer＇s outlet temperature （70 ℃）. As a result,the cold air quantity entered into the pulverizer can be reduced,and the boiler＇s exhaust gas temperature can decrease by 6 ℃ to 10 ℃. When high volatile bituminous coal is used,this temperature independent control technology obviously im- proves the anti-spontaneous combustion and anti-explosion quality in the pulverizer because of the lower pulverizer＇s outlet temperature. It increases the velocity and ensures the pulverized coal conveying security in pulverized-coal piping, especially at low boiler load. This technology can be used in direct-firing pulveri- zing system equipped with double-inlet and double-outlet steel-ball pulverizer or medium-speed pulverizer , and has great application prospects.