一种新型CFB锅炉循环灰冷却排放技术

A New Technology of Circulating Ash Cooling and Discharge for CFB Boiler

文中针对燃用高灰分劣质煤的CFB锅炉所产生的床温低、蒸汽温度低、返料不畅、底渣和飞灰可燃物含量高等问题进行深入分析,将原因归结为炉内灰浓度过高导致的炉内传热效率降低和分离器负担加重。为彻底解决上述问题,文中提出一种针对CFB锅炉的新型循环灰冷却排放技术,将炉内多余的循环灰冷却后直接排出,以达到降低炉内灰浓度的目的,并基于新技术研发出循环灰冷却排放系统。这个技术于2014年在山西某电厂进行工程应用,性能试验结果表明,本技术对改善锅炉运行参数有显著效果:在140、170和200 MW工况下,设备投运后床温分别提升11、25和64℃,再热汽温分别提升3、5和14℃。底渣和飞灰可燃物含量降低0.18和1.59%,回料器压力和床压等关键参数也有明显改善。18个月的长期监测结果表明,设备出力充足、运行稳定、故障率低,锅炉燃烧劣质煤时带负荷能力明显提高,对机组安全稳定地运行起到保障作用;监测期间锅炉热效率平均提高1.1%,发电煤耗降低4.3 g/k Wh,每年可为电厂带来直接经济效益500万元以上。这个技术可为燃用劣质的CFB锅炉提供一个有效的解决方案,具有广阔的市场前景。

The article studied on the problems of CFB boiler burning high ash coal. The problems mainly include low bed temperature, low vapor temperature, unsmooth circulating ash recycle, and high combustible material content in ash and slag. The key to solve these problems is to lower the circulating ash concentration in furnace. CERI presented a new circulating ash discharge technology for CFB boiler, which cooled and discharged some circulating ash off. This new technology was applied to certain 200 MW power plant in Shanxi province, and performance experiment shows great improvement on boiler operation parameters. Thermal efficiency of CFB boiler increases 1.1%, and coal consumption drops 4.3 g/kWh, bringing 5 million RMB benefit annually. This new technology provides an effective solution to CFB boiler burning fault coal, and has good market prospect.