ABSTRACT

Based on the idea of the decoupling combustion technology and considering the effect of the high temperature on the coking and slagging, a fusion decoupling combustion technical scheme is proposed. The technical scheme divides the continuous combustion process into the fusion gasification stage and gasified gas combustion stage. During the fusion gasification stage, the air required for the gasification reaction is preheated to keep the temperature in the gasification zone above the ash fusion temperature. Then, the high-temperature gas flows into the combustion zone. Meanwhile, the flue gas and the air required for the combustion are introduced, thereby ensuring the burnout of combustible components and decreasing the NOx emission. Corresponding process model is established on the Aspen Plus platform. Through comparison with experimental data, the rationality of the modelling method is verified. And the simulation results show that in the scheme, the mass fraction of carbon in raw biomass could be converted completely. With the increase of ER from 0.33 to 0.47, LHV of product gas decreases from 5.5 MJ/Nm³ to 1.5 MJ/Nm³. The rising preheating temperature could decrease the content of H₂ and increase the content of CO, which leads to that the LHV keeps the same, thereby that the effect of preheating temperature on the combustion zone could be ignored. The relationship between preheating temperature and the ratio of Air1 plays a decisive role in the implementation of the scheme. When the ratio of Air1 is equal to 0.47, the NO_x emission is lower than 70 mg/m³.

摘要

基于解耦燃烧技术的思想，考虑高温对结焦和结渣的影响，提出了熔解解耦燃烧技术方案。该技术方案将连续燃烧过程分为熔融气化阶段和气化气燃烧阶段。在熔融气化阶段，对气化反应所需的空气进行预热，使气化区温度保持在灰熔融温度以上。然后，高温气体流入燃烧区。同时引入燃烧所需的烟气和空气，保证了可燃成分的燃尽，减少了NOx的排放。在Aspen Plus平台上建立相应的流程模型。通过与实验数据的对比，验证了建模方法的合理性。并且模拟结果表明，在该方案中，原始生物质中碳的质量分数可以完全转化。随着ER从0.33增加到0.47，产品气的LHV从5.5 MJ/Nm下降³至 1.5 MJ/Nm ³。升高预热温度可以降低H ₂含量，增加CO含量，导致LHV保持不变，从而可以忽略预热温度对燃烧区的影响。预热温度与Air1比例的关系对方案的实施起着决定性的作用。当Air1的比例等于0.47时，NOx_排放量低于70mg/m ³。