Experimental study on stable combustion of pulverized coal stream in a confined small space with air jet

IF 5.1 3区工程技术 Q2 ENERGY & FUELS

Thermal Science and Engineering Progress Pub Date : 2024-11-02 DOI:10.1016/j.tsep.2024.103028

Lizhi Meng, Xiaoju Han, Zuodong Liu, Guojia Yao, Hong Tang, Lingfang Sun

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引用次数: 0

Abstract

Preheated pulverized coal self-sustaining stable combustion burners (PPSCBs) present a promising new avenue for advancing research on ultralow-load stable combustion and achieving ultralow NO_x emissions in thermal power boilers. Self-sustaining ignition burners (SIBs) serve as a continuous ignition heat source for PPSCBs. The self-sustained combustion characteristics of SIBs play a crucial role in the stable operation of PPSCBs. The stable combustion barrel as a practical model for pulverized coal combustion within confined spaces is the crucial component for SIBs to achieve self-sustained combustion and is the focus of the study. In this study, three structural types of combustion barrels are designed, namely the single-stage air forward jet, single-stage air reverse jet, and three-stage air reverse jet. Relevant data are collected to analyze the effect of varying the combustion temperature on pulverized coal within these combustion barrels. The findings reveal that under various experimental conditions, thermal equilibrium is not established for the single-stage air forward jet structure. However, for the single-stage air reverse jet structure, thermal equilibrium durations of 433 s and 335 s are observed under two operating conditions. The three-stage air reverse jet structure demonstrates thermal equilibrium durations of 3158 s and 3408 s under two operating conditions, with the latter maintaining thermal equilibrium until the conclusion of the experiment. Therefore, the arrangement of the air reverse jet has significant effect on combustion stability. The results of this study offer valuable insights for the subsequent development of SIB technologies.

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密闭狭小空间内煤粉流喷气稳定燃烧实验研究

预热煤粉自持稳燃燃烧器（PPSCB）为推进超低负荷稳燃研究和实现火电锅炉超低氮氧化物排放提供了一条前景广阔的新途径。自持续点火燃烧器（SIB）是 PPSCB 的持续点火热源。自持续点火燃烧器的自持续燃烧特性对 PPSCB 的稳定运行起着至关重要的作用。作为煤粉在密闭空间内燃烧的实用模型，稳定燃烧筒是 SIB 实现自持燃烧的关键部件，也是本研究的重点。本研究设计了三种结构类型的燃烧筒，即单级空气正向喷射、单级空气反向喷射和三级空气反向喷射。通过收集相关数据，分析了在这些燃烧筒内改变燃烧温度对煤粉的影响。研究结果表明，在各种实验条件下，单级空气正向喷射结构并没有达到热平衡。然而，对于单级空气反向喷射结构，在两种操作条件下观察到的热平衡持续时间分别为 433 秒和 335 秒。三级空气反向喷射结构在两种工作条件下的热平衡持续时间分别为 3158 秒和 3408 秒，后者一直保持热平衡状态直至实验结束。因此，空气反向射流的布置对燃烧稳定性有显著影响。本研究的结果为后续 SIB 技术的开发提供了宝贵的启示。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Thermal Science and Engineering Progress Chemical Engineering-Fluid Flow and Transfer Processes

CiteScore

7.20

自引率

10.40%

发文量

327

审稿时长

41 days

期刊介绍： Thermal Science and Engineering Progress (TSEP) publishes original, high-quality research articles that span activities ranging from fundamental scientific research and discussion of the more controversial thermodynamic theories, to developments in thermal engineering that are in many instances examples of the way scientists and engineers are addressing the challenges facing a growing population – smart cities and global warming – maximising thermodynamic efficiencies and minimising all heat losses. It is intended that these will be of current relevance and interest to industry, academia and other practitioners. It is evident that many specialised journals in thermal and, to some extent, in fluid disciplines tend to focus on topics that can be classified as fundamental in nature, or are ‘applied’ and near-market. Thermal Science and Engineering Progress will bridge the gap between these two areas, allowing authors to make an easy choice, should they or a journal editor feel that their papers are ‘out of scope’ when considering other journals. The range of topics covered by Thermal Science and Engineering Progress addresses the rapid rate of development being made in thermal transfer processes as they affect traditional fields, and important growth in the topical research areas of aerospace, thermal biological and medical systems, electronics and nano-technologies, renewable energy systems, food production (including agriculture), and the need to minimise man-made thermal impacts on climate change. Review articles on appropriate topics for TSEP are encouraged, although until TSEP is fully established, these will be limited in number. Before submitting such articles, please contact one of the Editors, or a member of the Editorial Advisory Board with an outline of your proposal and your expertise in the area of your review.