双油枪微油点火技术在燃用褐煤锅炉上的应用

APPLICATION OF TINY-OIL IGNITION WITH DOUBLE OIL GUNS TECHNOLOGY ON A LIGNITE BOILER

某200MW机组燃用褐煤的HG-670/13.7-HM18型锅炉通过在微油燃烧器内布置双油枪和在高温炉烟风道上加装油枪加热器等,解决了微油点火难的问题。实际运行结果表明,冷炉起动时,在给煤量为2～12t/h范围内,微油燃烧器内煤粉稳定着火和燃烧,锅炉升温升压速率在规程允许范围内。与采用传统的大油枪点火起炉方式相比,节油率可达到76%。

The retrofit of a conventional 200 MW unit with HG-670/13.7-HM18 type lignite boiler involving tiny-oil technology is discussed.The burner is equipped with a fan-mill pulverizing system in which the high-temperature flue gas is used as the desiccant.Some features of the existing lignite boiler against the application of tiny-oil technology are realized such as large flow rate of the fan-mill,low concentration of the pulverized coal during cold-starting of the boiler,large size of the primary nozzles,as well as the hexagonal arrangement of the burner.These concerns are successfully addressed by employing a duo-oil-gun arrangement in the combustor and an oil-gun heater in the flue duct.Experimental results of cold-starting of the retrofitted boiler show that,pulverized coal is able to be stably ignited and combusted within the feeding range of 2~12 t/h.Both the steam temperature and pressure rising rates satisfy the requirements of the operation rules.By applying the tiny-oil technology,an oil-saving rate of 76% is achieved.