Gas-Solid Flow, Combustion Characteristics, and Gas Emissions in a 75 t/h CFB Boiler Based on the CPFD Method

  • HUANG Xiankun ,
  • BAI Zhang ,
  • ZHU Xiaoli ,
  • WANG Shuoshuo ,
  • MU Lin ,
  • GONG Liang
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  • 1. College of New Energy, China University of Petroleum (East China), Qingdao 266580, China
    2. Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, School of Energy and Power Engineering, Dalian University of Technology, Dalian 116024, China

网络出版日期: 2025-01-09

基金资助

This work was supported by the National Natural Science Foundation of China (No. 52176030), Taishan Scholars Program of Shandong Province (No. tsqn202312115), Shandong Provincial Natural Science Foundation of China (No. ZR2022YQ58), and the Fundamental Research Funds for the Central Universities (No. 24CX06038A).

版权

Science Press, Institute of Engineering Thermophysics, CAS and Springer-Verlag GmbH Germany, part of Springer Nature 2025

Gas-Solid Flow, Combustion Characteristics, and Gas Emissions in a 75 t/h CFB Boiler Based on the CPFD Method

  • HUANG Xiankun ,
  • BAI Zhang ,
  • ZHU Xiaoli ,
  • WANG Shuoshuo ,
  • MU Lin ,
  • GONG Liang
Expand
  • 1. College of New Energy, China University of Petroleum (East China), Qingdao 266580, China
    2. Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, School of Energy and Power Engineering, Dalian University of Technology, Dalian 116024, China

Online published: 2025-01-09

Supported by

This work was supported by the National Natural Science Foundation of China (No. 52176030), Taishan Scholars Program of Shandong Province (No. tsqn202312115), Shandong Provincial Natural Science Foundation of China (No. ZR2022YQ58), and the Fundamental Research Funds for the Central Universities (No. 24CX06038A).

Copyright

Science Press, Institute of Engineering Thermophysics, CAS and Springer-Verlag GmbH Germany, part of Springer Nature 2025

摘要

研究采用计算粒子流体动力学(CPFD)方法进行了三维模拟,旨在分析75t/h工业级循环流化床(CFB)锅炉中煤炭燃烧的过程。研究系统性地评估了CFB锅炉从燃烧点火至稳定运行状态下的燃烧特性、气固流动行为以及气态污染物排放情况。结果显示,锅炉整体温度分布呈现出较为均匀的特征,随着燃烧过程在锅炉内部的逐步推进,气体成分的变化曲线清晰地揭示了CO2O2浓度之间存在的显著负相关关系,具体表现为CO2浓度随燃烧反应的进行而逐渐上升,同时O2浓度相应下降。这一反比关系凸显了燃烧反应的基本原理,即碳基燃料与氧气反应生成二氧化碳并释放能量。此外,综合分析结果显示从点火阶段至稳定燃烧阶段,NO和二氧化硫SO2的排放量均呈现出下降趋势。这种污染物排放量的减少可归因于燃烧效率的提升。更充分的燃烧减少了未燃烧碳氢化合物的生成,这些化合物是NO形成的重要前驱物。同时,燃料中的硫元素被更有效地转化为三氧化硫(SO3)或结合于硫酸盐中,从而有效降低了SO2的排放量。在模拟达到的稳定状态下,SO2的质量流量随炉膛高度的变化表现出明显的特征,从炉膛底部4米处的0.07 kg/s逐渐上升至炉膛中心8米处的峰值0.078 kg/s,随后在炉膛顶部20米处又降至0.06 kg/s。

本文引用格式

HUANG Xiankun , BAI Zhang , ZHU Xiaoli , WANG Shuoshuo , MU Lin , GONG Liang . Gas-Solid Flow, Combustion Characteristics, and Gas Emissions in a 75 t/h CFB Boiler Based on the CPFD Method[J]. 热科学学报, 2025 , 34(1) : 323 -336 . DOI: 10.1007/s11630-025-2092-7

Abstract

A 3D simulation using Computational Particle Fluid Dynamics (CPFD) methods was used to calculate coal combustion in a 75 t/h industrial-scale circulating fluidized bed (CFB) boiler. Combustion characteristics, gas-solid flow characteristics, and gaseous pollutant emissions of CFB boilers from combustion ignition to stable operation were systematically evaluated in this study. Results show that the temperature distribution is relatively uniform throughout the boiler. As the combustion process unfolds within the boiler, the gas composition curve strikingly portrays the inverse correlation between CO2 and O2 concentrations. As the combustion reaction progresses, it becomes evident that the concentration of CO2 progressively increases, while the concentration of O2 concurrently decreases. This inverse relationship underscores the fundamental combustion reaction, where carbon-based fuels react with oxygen to produce carbon dioxide and release energy. Furthermore, a comprehensive analysis has revealed that, from ignition to stable combustion, both nitric oxide (NO) and sulfur dioxide (SO2) emissions exhibit a declining trend. This reduction in pollutant generation is attributed to the improvement in combustion efficiency. More complete combustion leads to lower levels of unburned hydrocarbons, which are prone to NO formation. Similarly, the sulfur content in the fuel is more efficiently oxidized to sulfur trioxide (SO3) or bound in sulfates, reducing SO2 emissions. At steady state in the simulation, the SO2 mass flow rate varies significantly with the furnace height, gradually increasing from 0.07 kg·s–1 at 4 m at the bottom of the furnace to a peak of 0.078 kg·s–1 at 8 m in the center, and then decreasing to 0.06 kg·s–1 at 20 m at the top of the furnace.

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