CFB机组底渣余热回收方案的分析比较

Analysis and Comparison of the Bottom Slag Waste Heat Recovery Versions for a CFB( Circulating Fluidized Bed) Boiler Unit

以某厂300 MW循环流化床锅炉滚筒冷渣器和风水冷渣器联合排渣方式的机组为例,运用等效焓降法选取3种不同的底渣余热回收方案进行了计算分析、对比研究和实践验证。研究它们对机组热经济性的影响。结果表明:燃用煤的热值越低,底渣余热回收的利用空间越大,节能效果越明显。当选用最佳底渣余热回收方案时,机组热耗率可降低3.54-8.76 k J/(k W·h),标准煤耗降低0.133-0.329 g/(k W·h)。机组经过优化改造后,实际运行结果与上述理论分析结果相吻合,可对其它机组的余热利用提供借鉴和参考。

With a 300 MW CFB boiler unit operating in a combined slag removal mode by adopting roller slag coolers and airwater slag coolers serving as an example,the equivalent enthalpy drop method was used to calculate,analyze,contrast,study and case verify the influence of the three bottom slag waste heat recovery versions chosen on the cost-effectiveness of the unit. It has been found that the lower the heating value of the coal burned,the bigger the space for utilizing the bottom slag waste heat recovered and the more conspicuous the energy-saving effectiveness. When the optimum bottom slag waste heat recovery version is chosen,the heat rate of the unit can reduce by 3. 54 k J /( k W·h) to 8. 76 k J /( k W·h) and lower the standard coal consumed by 0. 133 g /( k W·h) to 0. 329 g /( k W·h). After the unit has been subjected to an optimization and reconstruction,the actual operation results are in good agreement with the theoretically analytic results above-mentioned,thus of fering reference for the waste heat utilization ofother units of the same kind.