燃煤机组掺烧富氢燃料发电能够大幅度降低机组碳排放，有望成为今后燃煤机组实现碳减排的重要途径。针对某电厂300 MW等级燃煤机组，基于能量守恒定律，通过锅炉热力校核计算分析了机组在不同工况下，NH3掺烧比例在20%～100%时对燃煤机组的影响。结果表明：大比例掺烧NH3后理论燃烧温度呈线性下降，省煤器出口烟温略有降低，排烟温度上升，锅炉热效率下降0.31～2.04个百分点；减温水量增加，原有受热面基本能够满足换热需要；增设专用燃烧器后可将烟气中的NOx控制在与燃煤相当的水平，最大可减排CO2约121.2万t/a;引风机需要进行扩容改造，对原有送风系统、脱硝和脱硫系统影响较小，可能需要对现有的低温烟气余热回收系统进行调整，同时也需要研究湿式电除尘或其他新型捕集系统，降低气溶胶类物质的排放。

The carbon emission of units can be greatly reduced by the power generation of coal-fired units mixed with hydrogen rich fuel. It is expected to be an important way for coal-fired units to achieve carbon emission reduction in the future. A thermal calculation and analysis of 300 MW power plant were studied based on the energy conservation law. The influence of the unit′s mixed combustion mass ratio of 20%-100% NH3 power generation on the coal-fired unit under different working conditions was analyzed through the boiler thermal check calculation. The results show that after coupling with 20%-100% NH3,the theoretical combustion temperature decreases linearly,the flue gas temperature at he economizer exit reduces slightly,the temperature of exit flue gas rises,the boiler thermal efficiency decreases by 0.31-2.04 percent points,the attempering water consumption increases,and the original heating surface can meet the requirment of heat exchange. Through adding the specific burner,the NOx emssion can achieve the same level as that of the original boiler,and the maximum annual emission reduction is about 1.12 million tons of CO2. The induced draft fan needs to be expanded,which has little impact on the original air supply system,denitrification and desulfurization system. It may be necessary to adjust the low-temperature flue gas waste heat recovery system and investigate the wet electrostatic precipitator or other new system to reduce the aerosol emission.

0 引言

1 计算基础参数

   1.1 机组概况

   1.2 设计煤质及NH3参数

   1.3 计算方法

2 计算结果与分析

   2.1 掺烧NH3发电对锅炉主要参数的影响

   2.2 掺烧NH3发电对燃煤机组烟风系统的影响

   2.3 掺烧NH3发电对燃煤机组制粉及燃烧系统的影响

   2.4 掺烧NH3发电对燃煤机组运行安全性的影响

   2.5 掺烧NH3发电对燃煤机组CO2排放的影响

   2.6 掺烧NH3发电对燃煤机组污染物排放的影响

3 结论