Research On Explosion Protection Of Pulverizer Based On Mixedly Burning Brown Coal

The supply of electricity and coal is tight, and price of coal is continuously rising. The inventory of coal in power plant is continuing to decrease at the same time. At present the trend of diversity in the coal supply of the power plant becomes more and more serious, which brings great hidden trouble to the long period operation of the power plant's boiler and safe production. At present the trend of diversity in the coal supply of the power plant becomes more and more serious, which brings great hidden trouble to the long period operation of the power plant's boiler and safe production. because it is hard to ensure burning and design kind of coal ,so some lignite of high volatile need to be added in burning. When burn the lignite of high volatile, unsafe conditions like spontaneous combustion, explosion etc. are easy to happen on powdering system, and the fire fighting and deflagration phenomenon are also apt to happen on the boiler. Accidents of boiler stopping working increase, and the economic security index of the unit decreases. Many boilers are hard to maintain their normal burning due to their low-load and poor ability of stable-combustion. So it is difficult to meet the requirement of growing difference of power grid's peak and valley.Some large units in coal-fired plants (above 300MW) of our country is usually equipped with the system of positive pressure and straight blow. The reality is that the power plants which using positive pressure and straight blow system whether domestically or abroad have ever happened fire or explosion. therefore, it is necessary to analyze the fire and explosion problems of the positive pressure and straight pressure system, so as to adopting necessary preventive measures to avoid the problems happening again.the paper has a deep research and analysis of the coal pulverizing system, operating characteristics of the pulverizer type and relations of the pulverizer and the kind of coal. It exerts much importance on researching the mechanism of powdering system explosion and influence of mixing burning with lignite on the safety system, and put forward the relative explosion- proof measures. What solutions are taken to the full extent to guarantee the pulverizing system's safety under the condition of mixing the lignite in burning.based on these, the paper introduces the advanced online CO detection technology to realize monitoring coal CO density currently and accurately for boiler burning changeable coals. And apply the CO data detected online to DCS system's secure alerting and controlling, which will improve the security of the current system and the quality of system control, and plays an important role in adjusting the objective conditions of mixing lignite in burning.