燃煤耦合垃圾焚烧发电技术可充分利用现有的燃煤机组和环保设施协同处理垃圾，降低垃圾发电成本，提高垃圾处理规模，降低存量煤电煤耗，提高非化石能源利用比例。目前燃煤耦合垃圾焚烧发电技术中耦合方式主要有：烟气侧耦合、燃料侧耦合和蒸气侧耦合3种。为研究烟气侧燃煤耦合垃圾焚烧发电技术，以220 t/h四角切圆煤粉锅炉为研究对象，提出了烟气侧燃煤耦合垃圾焚烧改造方案。其中改造前系统煤粉炉中煤粉单独燃烧，占总输入热量的100%，而改造后系统中垃圾热量替代总输入热量的5%和10%，而煤粉占总输入热量的95%和90%。利用Fluent数值模拟软件对改造前后的3种燃烧工况分别进行数值模拟。数值模拟结果表明：烟气侧耦合改造会使锅炉流场工况更加复杂，且垃圾替代燃煤热量比例越高影响越明显；炉膛截面平均温度分布受耦合烟气量的影响；出口截面烟气平均温度随垃圾替代燃煤热量比例的增加而升高,其中改造前煤粉单独燃烧时烟气出口温度为1 366.9 K，改造后5%垃圾替代燃煤热量系统的烟气出口平均温度升高到1 409.9 K，10%时烟气出口平均温度升高到1 420.1 K；炉膛出口处NO浓度随垃圾替代燃煤热量比例的增加而升高，相比于改造前煤粉单独燃烧，改造后5%垃圾替代燃煤热量系统的NO排放浓度增加了6.3%，10%替代时增加了13.0%；炉膛出口处SO2浓度随垃圾替代燃煤热量比例的增加而降低，相比改造前，改造后5%垃圾替代燃煤热量系统的SO2浓度降低40.9%，10%比例时降低41.4%。

The technology of coal fired coupled waste incineration power generation can make full use of the existing coal fired units and environmental protection facilities,co-processing waste,reduce waste-to-energy costs,improve the scale of waste treatment,and reduce the coal consumption of coal fired power,increase the proportion of non-fossil energy utilization. At present,there are three coupling modes in coal-fired coupled waste incineration power generation technology:flue gas side coupling,fuel side coupling and steam side coupling. In order to study the coupled incineration power generation technology,a coupling transformation scheme based on a 220 t/h tangentially pulverized coal boiler was proposed. Among them,the pulverized coal in the pulverized coal boiler of the system before transformation is burned alone,accounting for 100% of the total input calorific,and after the transformation,the waste calorific replaces 5% and 10% of the total input calorific,while the pulverized coal accounts for 95% and 90% of the total input calorific. The combustion conditions before and after the transformation were analyzed by Fluent simulated. The results show that the flue gas side coupling transformation will make the boiler flow field more complex,and the higher the proportion of waste replacing coal calorific is,the more obvious the impact is；the average temperature of the furnace section is affected by the coupled flue gas volume. The average flue gas temperature at the outlet section increases with the increase of the calorific ratio of waste to coal. The flue gas outlet temperature is 1 366.9 K when pulverized coal is burned alone before the transformation. After the transformation,the average flue gas outlet temperature of the 5% waste to coal calorific ratio system increases to 1 409.9 K,and the average flue gas outlet temperature increases to 1 420.1 K when 10%；the NO concentration at the furnace outlet increases with the increase of the calorific proportion of waste replacing coal. Compared with the separate combustion of pulverized coal before the transformation,the NO emission concentration of the 5% waste replacing coal calorific proportion system after the transformation increases by 6.3% and 13.0% when the proportion system is 10%；the SO2 concentration at the furnace outlet decreases with the increase of the calorific proportion of waste replacing coal. Compared with that before the transformation,the SO2 concentration of the 5% waste replacing coal calorific proportion system after the transformation decreases by 40.9%,and that of the 10% proportion system decreases by 41.4%.

0 引言

1 燃煤锅炉改造与模拟工况

   1.1 燃煤锅炉改造

   1.2 模拟工况

2 网格划分与数值模型

   2.1 锅炉燃烧区域和回转窑网格划分

   2.2 系统数值模型

3 模拟结果与分析

   3.1 炉膛流场流动特性

   3.2 炉膛截面温度特性

   3.3 污染物分布特性

   3.4 燃烧模型验证

4 结论