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Experimental study of rotating gliding arc discharge plasma-assisted combustion in an aero-engine combustion chamber
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作者 Liming HE Yi CHEN +3 位作者 Jun DENG Jianping LEI Li FEI Pengfei LIU 《中国航空学报:英文版》 SCIE EI CAS CSCD 2019年第2期337-346,共10页
The combustion chamber is the core component of an aero-engine, and affects its reliability and security operation, even the performance of the aircraft. In this work, a Plasma-Assisted Combustion(PAC) test platform w... The combustion chamber is the core component of an aero-engine, and affects its reliability and security operation, even the performance of the aircraft. In this work, a Plasma-Assisted Combustion(PAC) test platform was developed to validate the feasibility of using PAC actuators to enhance annular combustor performance. Two plans of PAC(rotating gliding arc discharge plasma) were designed, Assisted Combustion from Primary Holes(ACPH) and Assisted Combustion from Dilution Holes(ACDH). Comparative experiments and analysis between conventional combustion and PAC were conducted to study the effects of ACPH and ACDH on the performances including average outlet temperature, combustion efficiency, pattern factor under four different excessive air coefficients(0.8, 1, 2, and 4), and lean blowout performance at different inlet airflow velocities. Experimental results show that the combustion efficiency is improved after PAC compared with that in normal conditions, and the combustion efficiency of ACPH increases2.45%, 1.49%, 1.04%, and 0.47%, while it increases 2.75%, 1.67%, 1.36%, and 0.36% under ACDH conditions. The uniformity of the outlet temperature field and the lean blowout performance are improved after PAC. Especially for ACPH, the widening of the lean blowout limit is8.3%, 12.4%, 12.8%, and 25% respectively when the inlet velocity ranges from 60 m/s to120 m/s. These results offer new perspectives for using PAC devices to enhance aero-engine combustors’ performances. 展开更多
关键词 AERO-ENGINE Assisted COMBUSTION ACTUATOR COMBUSTION CHAMBERS Plasma-Assisted COMBUSTION ROTATING GLIDING arc discharge
玉米秸秆成型生物炭燃烧特性与动力学分析
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作者 范方宇 邢献军 +3 位作者 施苏薇 杨静 糜梦星 朱国婷 《太阳能学报》 EI CAS CSCD 北大核心 2019年第4期1100-1106,共7页
采用热重法对玉米秸秆成型颗粒及生物炭燃烧特性及动力学进行研究,并考察不同升温速率下(10、20、40℃/min)对320、500℃热解生物炭燃烧特性的影响,分析其燃烧特性及动力学参数。结果表明:玉米秸秆成型颗粒炭化后其燃烧热重分析(DTG)曲... 采用热重法对玉米秸秆成型颗粒及生物炭燃烧特性及动力学进行研究,并考察不同升温速率下(10、20、40℃/min)对320、500℃热解生物炭燃烧特性的影响,分析其燃烧特性及动力学参数。结果表明:玉米秸秆成型颗粒炭化后其燃烧热重分析(DTG)曲线呈现多峰状态,峰整体向高温区转移;玉米秸秆成型颗粒的着火温度和燃尽温度均小于生物炭,综合燃烧特性指数(SN)大于各温度热解炭化后样品。随着炭化温度的升高,成型生物炭着火温度和燃尽温度升高,SN减小;一级反应动力学能很好地描述各样品的燃烧动力学,相关系数(R~2)均高于0.9。 展开更多
关键词 玉米秸秆成型颗粒 生物炭 燃烧 动力学 综合燃烧特性指数
热解温度对煤泥焦燃烧及产物析出特性影响 预览
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作者 龚德鸿 张晓婉 《热力发电》 CAS 北大核心 2019年第6期84-89,共6页
采用热重-质谱联用系统对不同热解温度所制煤泥焦进行燃烧实验,研究了热解温度对煤泥焦的燃烧特性及NH3、NO、SO2、CO2析出特性的影响,并运用C-R法计算煤泥焦的活化能及指前因子。结果表明:热解温度对煤泥焦的燃烧特性影响较大,可燃性... 采用热重-质谱联用系统对不同热解温度所制煤泥焦进行燃烧实验,研究了热解温度对煤泥焦的燃烧特性及NH3、NO、SO2、CO2析出特性的影响,并运用C-R法计算煤泥焦的活化能及指前因子。结果表明:热解温度对煤泥焦的燃烧特性影响较大,可燃性指数、燃烧稳定性指数、综合燃烧指数均随热解温度升高而减小;热解温度对NH3、NO、SO2、CO2的析出特性有一定影响,其析出相对累积量均随热解温度升高而降低;煤泥焦活化能随着热解温度升高明显提高,而且煤泥焦燃烧存在动力学补偿效应。 展开更多
关键词 煤泥焦 燃烧 热重-质谱 燃烧产物 动力学 补偿效应 热解温度
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柴油机催化型颗粒捕集器喷油助燃再生特征 预览
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作者 张韦 陈朝辉 +2 位作者 孔孟茜 赵罗峰 包广元 《农业工程学报》 EI CAS CSCD 北大核心 2019年第8期92-99,共8页
针对在用车辆的排放升级改造,以及满足非道路移动源四阶段排放标准限制要求,该文基于自主开发的喷油助燃主动再生系统,开展了加装DPF(diesel particulate filter)和不同CDPF(catalyzed diesel particulate filter)后处理器的发动机外特... 针对在用车辆的排放升级改造,以及满足非道路移动源四阶段排放标准限制要求,该文基于自主开发的喷油助燃主动再生系统,开展了加装DPF(diesel particulate filter)和不同CDPF(catalyzed diesel particulate filter)后处理器的发动机外特性试验和喷油助燃主动再生燃烧试验。结果表明:催化剂负载量为530g/m^3的CDPF,对外特性下发动机的动力性和经济性影响较小,并为碳烟再生提供了充足的NO2组分,因而其最大排气压差比DPF低8.8kPa。630℃时无二次供气的CDPF其再生效率高达96.4%,载体最高温度比DPF低31℃;采用二次供气速率1.25L/s、时长180s,继续供气速率0.625 L/s、时长420 s的再生方案,600℃时CDPF的再生效率为83.2%,载体最高温度比无二次供气时降低了64℃;进行停机再生与怠速再生时,催化剂负载量为530 g/m3的CDPF具有更好的再生特性,其停机再生效率为76.4%,怠速再生效率达到88.5%。本研究对开发安全、高效的主动再生系统具有借鉴意义,并可为催化条件下的主动再生策略研究提供数据支撑。 展开更多
关键词 柴油机 燃烧 催化剂 再生 DPF CDPF 喷油助燃 台架试验
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煤泥燃烧产物析出特性的热重-质谱联用分析
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作者 张晓婉 龚德鸿 《热能动力工程》 CAS CSCD 北大核心 2019年第5期77-83,共7页
为研究含水率和升温速率对煤泥燃烧产物析出特性的影响,采用热重-质谱联用系统对煤泥进行燃烧实验,重点研究了5种含水率和3种升温速率条件下CO、CO2、NO、NO2的析出特性。实验结果表明:CO析出主要发生在焦炭燃烧阶段,CO2、NO、NO2在挥... 为研究含水率和升温速率对煤泥燃烧产物析出特性的影响,采用热重-质谱联用系统对煤泥进行燃烧实验,重点研究了5种含水率和3种升温速率条件下CO、CO2、NO、NO2的析出特性。实验结果表明:CO析出主要发生在焦炭燃烧阶段,CO2、NO、NO2在挥发份和焦炭燃烧阶段均有析出,析出温度范围分别在300~360℃和360~680℃;含水率对燃烧产物的析出特性影响较小;升温速率对燃烧产物析出有明显影响,随着升温速率增加,CO、CO2、NO、NO2的析出强度均增大,析出峰值温度均向高温区移动。 展开更多
关键词 煤泥 燃烧 热重-质谱 燃烧产物
气化细渣基础燃烧特性试验研究 预览
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作者 杜杰 戴高峰 +3 位作者 李帅帅 王学斌 孙晓伟 谭厚章 《洁净煤技术》 CAS 2019年第2期83-88,共6页
煤气化过程中产生大量含碳量较高的气化细渣,其填埋处理不仅占用大量土地,污染土壤和水体,同时造成能源浪费,如何高效环保地对气化细渣进行资源化利用是目前研究的热点。在获得气化细渣工业分析、元素分析、粒径分布、灰成分和微观形貌... 煤气化过程中产生大量含碳量较高的气化细渣,其填埋处理不仅占用大量土地,污染土壤和水体,同时造成能源浪费,如何高效环保地对气化细渣进行资源化利用是目前研究的热点。在获得气化细渣工业分析、元素分析、粒径分布、灰成分和微观形貌等基础上,利用热重对气化细渣单独燃烧及与燃料煤混合燃烧特性进行研究,对比了气化细渣与典型煤种燃烧特性的差异,并考虑掺混比例对混燃的影响。研究结果表明:气化细渣的Mar=69.7%,Ad=54.5%,w(Cd)=43.4%,Qgr,d=16.14MJ/kg,干化后的气化细渣中碳含量和发热量与对比劣质烟煤相当;干燥后的气化细渣粒径普遍小于200μm,且孔隙结构发达,电镜结果显示其微观结构由球形颗粒和不规则多孔形状颗粒组成。气化细渣与其他煤种燃烧特性对比表明:气化细渣的着火温度和燃尽温度分别为601.6℃和680.8℃,着火和燃尽特性比对比煤样和对应的原煤略差。气化细渣和原煤在不同掺烧比例下的热重燃烧试验结果表明,气化细渣和原煤掺烧存在显著的协同效应,与原煤掺烧能显著改进气化细渣的燃烧特性,在25%气化细渣掺烧比例下,气化细渣的燃烧特性得到显著改善,且相比于纯烧原煤,掺烧气化细渣后混煤的燃烧特性未显著下降。研究结果表明,干化后高含碳量的气化细渣极具应用价值,且与原煤掺烧对混煤的燃烧特性影响较小,还能显著改进混煤的燃烧特性,将干化后的气化细渣与原煤掺烧是一种可行的利用气化细渣热值的技术方案。 展开更多
关键词 气化细渣 燃烧 热重 混燃 协同效应
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预混燃烧下环境温度对某型燃气轮机燃烧稳定性和NOx排放影响的数值研究 预览
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作者 肖俊峰 李晓丰 +2 位作者 高松 王峰 王玮 《燃气轮机技术》 2019年第2期27-33,共7页
环境温度通过改变燃烧室入口空气温度进而影响燃气轮机燃烧稳定性和NOx排放。为了掌握预混燃烧模式下环境温度对燃气轮机燃烧稳定性和NOx排放的影响规律,本文以某重型燃气轮机燃烧室为研究对象,采用SAS湍流模型和涡耗散概念燃烧模型,通... 环境温度通过改变燃烧室入口空气温度进而影响燃气轮机燃烧稳定性和NOx排放。为了掌握预混燃烧模式下环境温度对燃气轮机燃烧稳定性和NOx排放的影响规律,本文以某重型燃气轮机燃烧室为研究对象,采用SAS湍流模型和涡耗散概念燃烧模型,通过改变环境温度,对多旋流喷嘴燃烧室预混燃烧模式下燃烧稳定性和NOx排放进行了数值计算。研究结果表明:在燃气轮机预混燃烧模式下,提升燃气轮机环境温度,有利于提高燃烧室燃烧稳定性;环境温度从0℃上升到30℃,在不调整燃料和空气流量的情况下,燃烧室出口NOx排放质量分数增加97.8%。 展开更多
关键词 燃气轮机 燃烧 燃烧稳定性 环境温度 数值仿真
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DICI发动机燃用生物柴油振动特性研究 预览
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作者 吴刚 江国和 +2 位作者 楼海军 杨智远 贺献忠 《中国油脂》 CAS CSCD 北大核心 2019年第1期148-152,共5页
通过将发动机外在的振动信号经过变换与缸内的燃烧放热规律相结合,以对DICI发动机燃用生物柴油后引起的振动进行协同特性研究。具体方法为,将餐饮废油生物柴油以10%掺混作为测试燃料,在常用工况下对缸盖振动信号和缸内燃烧压力进行采集... 通过将发动机外在的振动信号经过变换与缸内的燃烧放热规律相结合,以对DICI发动机燃用生物柴油后引起的振动进行协同特性研究。具体方法为,将餐饮废油生物柴油以10%掺混作为测试燃料,在常用工况下对缸盖振动信号和缸内燃烧压力进行采集。通过将小波尺度进行重排计算、振动功率密度计算和缸内压力计算,得到振动时间谱图、功率密度谱图和燃烧放热率等。结果表明:燃用B10生物柴油后,发动机整体振动频率从约4 200 Hz降低至约2 900 Hz。这主要由于生物柴油高黏度和低热值等特性导致缸内燃烧有所弱化,因而导致发动机振动的降低。生物柴油在整个频段上振动分布表现更为均匀,将对人体舒适度的提高和发动机寿命的延长有所贡献。 展开更多
关键词 生物柴油 柴油机 燃烧 振动特性 故障诊断 谱分析
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蔗渣锅炉低氮燃烧及烟气环保双达标排放技术探讨 预览
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作者 施晓明 《环境与发展》 2019年第3期68-68,70共2页
本文着重分析和研究低氮燃烧技术,并且与蔗渣锅炉烟气环保排放的现状进行结合,提出低氮燃烧的理念,并且从入炉燃烧方面入手,进一步加强压榨装嵌技术的管理,为锅炉提供较好的燃料。通过粗细渣分离、干燥烘干,降低入炉蔗渣的水分和颗粒度... 本文着重分析和研究低氮燃烧技术,并且与蔗渣锅炉烟气环保排放的现状进行结合,提出低氮燃烧的理念,并且从入炉燃烧方面入手,进一步加强压榨装嵌技术的管理,为锅炉提供较好的燃料。通过粗细渣分离、干燥烘干,降低入炉蔗渣的水分和颗粒度,提高热效率。采用锅炉低氮燃烧技术,对锅炉燃烧操作进行优化,进一步控制成本,让蔗渣锅炉排烟环保双达标的目的得以实现,与此同时,从实践和理论方面入手,探讨可行性方案。 展开更多
关键词 NO_x 燃烧 粉碎 细颗粒
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Numerical Investigation of the Effect of Hydrogen Enrichment on an Opposed-Piston Compression Ignition Diesel Engine
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作者 ZHOU Jianhao SHENG Xueshuang HE Longqiang 《热科学学报:英文版》 SCIE EI CAS CSCD 2019年第4期669-681,共13页
High power-to-weight and fuel efficiency are bounded with opposed-piston compression ignition(OPCI)engine,which makes it ideal in certain applications.In the present study,a dynamic three-dimensional CFD model was est... High power-to-weight and fuel efficiency are bounded with opposed-piston compression ignition(OPCI)engine,which makes it ideal in certain applications.In the present study,a dynamic three-dimensional CFD model was established to numerically investigate the combustion process and emission formation of a model OPCI engine with hydrogen enrichment.The simulation results indicated that a small amount of hydrogen was efficient to improve the indicated power owing to the increased in-cylinder pressure.Hydrogen tended to increase the ignition delay of diesel fuel due to both dilution and chemical effect.The burning rate of diesel fuel was apparently accelerated when mixing with hydrogen and premixed combustion became dominated.Nox increased sharply while soot was sufficiently suppressed due to the increase of in-cylinder temperature.Preliminary modifications on diesel injection strategy including injection timing and injection pressure were conducted.It was notable that excessive delayed injection timing could reduce Nox emission but deteriorate the indicated power which was mainly attributed to the evident decline of hydrogen combustion efficiency.This side effect could be mitigated by increasing the diesel injection pressure.Appropriate delay of injection coupled with high injection pressure was suggested to deal with trade-offs among Nox,soot and engine power. 展开更多
关键词 TWO-STROKE opposed-piston compression IGNITION hydrogen combustion
Reaction mechanism of arsenic capture by a calcium-based sorbent during the combustion of arsenic-contaminated biomass: A pilot-scale experience
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作者 Mei Lei Ziping Dong +3 位作者 Ying Jiang Philip Longhurst Xiaoming Wan Guangdong Zhou 《中国环境科学与工程前沿:英文版》 SCIE EI CAS CSCD 2019年第2期105-113,共9页
Large quantities of contaminated biomass due to phytoremediation were disposed through combustion in low-income rural regions of China.This process provided a solution to reduce waste volume and disposal cost.Pilot-sc... Large quantities of contaminated biomass due to phytoremediation were disposed through combustion in low-income rural regions of China.This process provided a solution to reduce waste volume and disposal cost.Pilot-scale combustion trials were conducted for in site disposal at phytoremediation sites.The reaction mechanism of arsenic capture during pilot-scale combustion should be determined to control the arsenic emission in flue gas.This study investigated three Pteris vittata L.biomass with a disposal capacity of 600 kg/d and different arsenic concentrations from three sites in China.The arsenic concentration in flue gas was greater than that of the national standard in the trial with no emission control,and the arsenic concentration in biomass was 486 mg/kg.CaO addition notably reduced arsenic emission in flue gas,and absorption was efficient when CaO was mixed with biomass at 10% of the total weight.For the trial with 10% CaO addition,arsenic recovery from ash reached 76%,which is an ~8-fold increase compared with the control.Synchrotron radiation analysis confirmed that calcium arsenate is the dominant reaction product. 展开更多
关键词 ARSENIC contamination PHYTOREMEDIATION Emission control Calcium-based sorbent BIOMASS disposal PILOT-SCALE COMBUSTION
Effects of High-temperature Char Layer and Pyrolysis Gas on NOx Reduction in a Typical Decoupling Combustion Coal-fired Stove
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作者 LI Honglin BAN Jian +3 位作者 ZHANG Nan LIU Xinhua HE Jingdong DU Wei 《热科学学报:英文版》 SCIE EI CAS CSCD 2019年第1期40-50,共11页
The suppression of nitrogen oxides (NOx)is the key to reducing pollutant emission of a domestic coal-fired stove due to the limitation of technology condition and economic cost.The decoupling combustion (DC) technolog... The suppression of nitrogen oxides (NOx)is the key to reducing pollutant emission of a domestic coal-fired stove due to the limitation of technology condition and economic cost.The decoupling combustion (DC) technology invented by Institute of Process Engineering (IPE),Chinese Academy of Sciences (CAS)is characterized by that a traditional stove is separated into a pyrolysis and a combustion chamber as well as a bottom passage between them.In this study,the.combustion of briquette from bituminons coal in different operation modes in a typical decoupling stove is tested and simulated to validate the advantage of DC technology over so-caUed reverse combustion.The smokeless and high-efficiency combustion of bituminous briquette with low emissions of NOx and CO can be implemented by utilizing low NOx combustion under low temperature and reduction atmosphere in the pyrolysis chamber as well as after-combustion of char and pyrolysis gas under high temperature and oxidation atmosphere in the combustion chamber.The effects of the main reducing components in pyrolysis gas as well as char on NOx reduction were numerically investigated in this study,which shows that the reducing ability increases gradually from CH4,CO to char,but the combined reducing ability of them cannot be determined by a simple addition. 展开更多
关键词 DECOUPLING COMBUSTION low NOx emission domestic STOVE numerical simulation bituminous BRIQUETTE thermal efficiency
Numerical Investigation of the Effects of Rate-Shaped Main Injection on Combustion and Emission in an OPOC Two-Stroke Diesel Engine 预览
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作者 Lei Zhang Tiexiong Su +3 位作者 Yunpeng Feng Fukang Ma Yangang Zhang Jun Wang 《北京理工大学学报:英文版》 EI CAS 2019年第2期226-233,共8页
The effects of various split injection strategies on the opposed-piston opposed-cylinder(OPOC)diesel engine combustion and emission characteristics have been studied numerically using AVL-Fire CFD tools.The five rate-... The effects of various split injection strategies on the opposed-piston opposed-cylinder(OPOC)diesel engine combustion and emission characteristics have been studied numerically using AVL-Fire CFD tools.The five rate-shaped main injections were used in split injection strategies.The results show that ignition delay from a rectangular injection rate is the shortest.Maximum pressure of the trapezoid injection rate is the largest.And the NOx emission of the rectangular injection rate is the largest.Meanwhile,the soot emission of the trapezoid injection rate is the least among the five injection rates. 展开更多
关键词 opposed-piston opposed-cylinder(OPOC)diesel engine split INJECTION rated-shape MAIN injection:numerical simulation combustion emissions
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沥青及各组分热重分析 预览
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作者 李晓东 《山西建筑》 2019年第14期80-82,共3页
对沥青的组分分离实验进行了概述,通过沥青及各组分的热重分析实验,具体分析了沥青各组分的热解特性,取得的结论对阻燃抑烟路面研究具有参考意义。
关键词 沥青 组分 热重分析
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制备工艺对民用型焦抗压强度及燃烧性能与污染物排放特性的影响 预览
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作者 孟佳文 曾泽泉 +3 位作者 刘勇进 宁卫云 韩小金 黄张根 《煤炭转化》 CAS CSCD 北大核心 2019年第1期48-56,共9页
以无烟煤煤末为主要原料,制备了高强度的民用型焦;研究了黏结剂配比和炭化温度对型焦抗压强度、燃烧性能和污染物排放特性的影响规律;通过扫描电子显微镜(SEM)观察了型焦结构的变化;利用热质联用仪(TG-MS)测试了型焦的燃烧性能和污染物... 以无烟煤煤末为主要原料,制备了高强度的民用型焦;研究了黏结剂配比和炭化温度对型焦抗压强度、燃烧性能和污染物排放特性的影响规律;通过扫描电子显微镜(SEM)观察了型焦结构的变化;利用热质联用仪(TG-MS)测试了型焦的燃烧性能和污染物排放特性。结果表明:实验条件下黏结剂的最佳配比为4%(质量分数,下同)腐植酸钠、2%羧甲基纤维素钠、2%沥青。随着炭化温度的升高,型焦的抗压强度和发热量不断提高,可燃性、燃尽特性和综合燃烧特性不断变差。燃烧时NO的释放量随着炭化温度的升高先减小后增大,炭化温度为700℃时,型焦燃烧NO的释放量最低。SO2的释放量随着炭化温度的升高不断增加,炭化温度为600℃时,型焦燃烧SO2的释放量最低。 展开更多
关键词 型焦 燃烧 污染物排放 黏结剂 炭化温度
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Effect of weathering on physico-chemical properties and combustion behavior of an Indian thermal coal 预览
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作者 Subhajit Aich Barun Kumar Nandi Sumantra Bhattacharya 《国际煤炭科学技术学报:英文版》 2019年第1期51-62,共12页
An open air stockpile of conical shape was formed with 3.5 m base diameter and 5 m height using 500 tons of -200 mm size ROM thermal coal on a concrete floor. Coal sample from the stockpile were collected at 30 days i... An open air stockpile of conical shape was formed with 3.5 m base diameter and 5 m height using 500 tons of -200 mm size ROM thermal coal on a concrete floor. Coal sample from the stockpile were collected at 30 days interval for analysis of various chemical properties like;proximate analysis, ultimate analysis, gross calorific value (GCV) and various combustion related properties such as ignition temperature, peak temperature, burnout temperature, maximum combustion rate, ignition index, burnout index, combustion performance index and combustion rate intensity index. Experimental results show that, due to weathering of coal fixed carbon decreased from 35.6% to 19.9%, elemental carb on (C) decreased from 46.6% to 28.6%, hydrogen (H) decreased from 3.3% to 2.9% and GCV decreased by up to 55% of original value during 330 days of storage of coal in an open atmosphere. Ash con tent of coal increased form 29.2% to 46.6% due to loss of combustibles. Sulfur (S) of coal was found to get increased from 0.33% to 1.08% during storage. The activation energy of coal combustion increased from 22 kJ/mol to 54 kJ/mol. Variation in combustion parameters signifies that weathering has significant negative impact on coal combustion properties as coal become difficult to ignite. 展开更多
关键词 WEATHERING of COAL TGA-DTG Combustibles COAL COMBUSTION Activation energy
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A comprehensive CFD combustion model for supercritical CFB boilers
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作者 Linjie Xu Leming Cheng +2 位作者 JieqiangJi Qinhui Wang Mengxiang Fang 《中国颗粒学报:英文版》 SCIE EI CAS CSCD 2019年第2期29-37,共9页
A combustion model of a large-scale supercritical circulati ng fluidized bed (CFB) boiler was developed for comprehensive computational-fluid-dynamics analysis. The model incorporates gas-solid hydrodynamics, coal com... A combustion model of a large-scale supercritical circulati ng fluidized bed (CFB) boiler was developed for comprehensive computational-fluid-dynamics analysis. The model incorporates gas-solid hydrodynamics, coal combustion, heat transfer on heat exchange surfaces in the furnace, and heat transfer between fumace and working medium in the heat transfer tubes. In simulating the dense and dilute phases in the fumace, the gas-solid hydrodynamics is based on the Euler-Euler model and energy-minimization multiscale drag model. Coal combustion entails evaporation, devolatilization, char combustion, gas homoge neous reaction, and pollutant emission. The coefficient ofheat transfer between gas-solid and the waterwall is estimated using the cluster renewal model, and for radiation, the discrete ordinate model is used. Moreover, thermohydraulic processes in the membrane wall are also in eluded in the heat transfer process. The model was successfully applied in simulations of a 350-MW supercritical CFB boiler. Detailed distributions of solids concentration, oxygen, heat flux, and working medium temperature in the boiler furnace are presented. 展开更多
关键词 COMPREHENSIVE combustion model COMPUTATIONAL fluid dynamic THERMAL-HYDRAULICS SUPERCRITICAL CIRCULATING fluidized bed Large-scale FURNACE
Effects of Chemical Reactions in the Hypersonic Reacting Flow around Blunt Bodies 预览
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作者 ZHAO Faming WANG Jiangfeng +1 位作者 FAN Xiaofeng YANG Tianpeng 《南京航空航天大学学报:英文版》 EI CSCD 2019年第1期71-79,共9页
The effects of chemical reactions in the hypersonic reacting flow are investigated using an integrated algorithm considering simultaneously two different reaction mechanisms,i.e.,including the high temperature air non... The effects of chemical reactions in the hypersonic reacting flow are investigated using an integrated algorithm considering simultaneously two different reaction mechanisms,i.e.,including the high temperature air non?equilibrium chemical reactions and the H2- air combustion reactions. The program is validated by the air non-equilibrium flow at Mach number of 25.9 with the RAM C-II configuration and the shock-induced combustion flow at Mach number of 4.512 6 around a sphere,respectively. Furthermore,the mixed reacting flow with the Mach number of 10.0 with an opposing jet of hydrogen is numerically analyzed. The results show that the program is reliable,and the effects of chemical reactions engender in the decrease of peak temperature along characteristic lines,as well as on the surface. The production of water is augmented in the region with high ratio of oxygen to hydrogen and weakened in the area with low ratio of oxygen to hydrogen by the air chemical non-equilibrium effects. 展开更多
关键词 HYPERSONIC air CHEMICAL NON-EQUILIBRIUM combustion EFFECTS of CHEMICAL reaction
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组喷孔喷嘴对双对置柴油机喷雾及燃烧的影响
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作者 周健豪 盛雪爽 +2 位作者 杨海青 赵万忠 宋廷伦 《航空动力学报》 EI CAS CSCD 北大核心 2019年第1期18-26,共9页
针对双对置柴油机混合气形成困难的特点,采用CONVERGE CFD软件,建立双对置柴油机数值仿真模型。设计3种汇聚型组喷孔喷嘴的喷孔布置方案,研究在保持喷油压力不变的前提下,对3种方案下喷雾、混合气形成和燃烧过程进行分析。结果表明:与... 针对双对置柴油机混合气形成困难的特点,采用CONVERGE CFD软件,建立双对置柴油机数值仿真模型。设计3种汇聚型组喷孔喷嘴的喷孔布置方案,研究在保持喷油压力不变的前提下,对3种方案下喷雾、混合气形成和燃烧过程进行分析。结果表明:与传统喷嘴相比,改进后的组喷孔喷嘴对喷雾贯穿距影响较小,有利于缸内湍流动能的提高,加快缸内混合气的形成速率。同时,组喷孔喷嘴使燃油分布更加均匀,分布区域也更广,有利于改善油气混合质量,提高双对置发动机气缸压力和燃烧效率,达到提升双对置发动机性能的效果。其中,第3种组喷孔布置方案下发动机指示功率可提高7.6%。 展开更多
关键词 组喷孔喷嘴 双对置柴油机 喷雾 混合气形成 燃烧
性质相近的弹性纺织纤维的鉴别方法比较 预览
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作者 王林霞 许秋梅 《绍兴文理学院学报》 2019年第7期38-43,共6页
通过使用常规纺织纤维鉴别方法,鉴别氨纶纤维、锦纶纤维、腈纶弹性纺织纤维.燃烧法、红外光谱法(ATR技术)仅能鉴别出氨纶弹性纤维,而纺织样品经过燃烧后采用扫描电镜(SEM)技术可鉴别三种性质相近的纺织弹性纤维.试验表明:各纺织弹性纤维... 通过使用常规纺织纤维鉴别方法,鉴别氨纶纤维、锦纶纤维、腈纶弹性纺织纤维.燃烧法、红外光谱法(ATR技术)仅能鉴别出氨纶弹性纤维,而纺织样品经过燃烧后采用扫描电镜(SEM)技术可鉴别三种性质相近的纺织弹性纤维.试验表明:各纺织弹性纤维在400℃以下充分燃烧1h后,氨纶弹性纤维微观形貌仍能保持纤维状结构,锦纶弹性纤维呈大块状,腈纶弹性纺织纤维呈大颗粒状.燃烧温度升高至500℃,仍能通过SEM图像区分三类纺织纤维;当温度升至600℃时,各纺织弹性纤维粉化现象加剧,形貌几乎相似.扫描电镜(SEM)技术是一种简单实用、高效的鉴别纺织弹性纤维的检测方法. 展开更多
关键词 弹性纤维 燃烧法 红外光谱法 扫描电子显微镜 鉴别
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