混煤一维火焰燃烧时硫析出特性的试验研究

以高硫贫煤为研究对象,通过分别加入低硫贫煤和低硫烟煤组成混煤来研究它们的硫析出特性。在试验中,研究了各单煤的燃烧性能、掺配比与SO2、H2S析出特性的关系。结果表明:单煤的燃烧性能对混煤影响较大;混煤的SO2排放浓度基本介于各单煤之间,但混煤H2S析出浓度却没有明显的规律性;贫煤和贫煤混煤与贫煤和烟煤混煤的硫析出有一定的差异。图9表3参9     

无烟煤与贫煤混煤燃烧和NO_x排放特性的实验研究

利用热天平和小型煤粉燃烧实验台对无烟煤、贫煤及其三种配比混煤的燃烧特性、不同配风下NOx的生成规律和燃尽特性进行了实验研究。通过对试验数据的整理和分析,认为无烟煤与贫煤在燃烧性能上略有差异,混煤的燃烧特性介于两者之间,合适的选取过量空气系数可实现不同掺烧比无烟煤与贫煤混煤高效低NO燃烧。并针对三种掺烧比的混煤提出了其高效低污染燃烧的过量空气系数范围,为燃用上述混煤的电厂经济清洁运行提供一些参考数据。     

燃煤粉锅炉受热面结焦及预防

燃煤粉锅炉，主要适用于燃烧反应低的无烟煤和贫煤的混合煤质，其结构与常规燃煤锅炉不同，易于实现燃烧过程的多级配风。即可控制着火阶段的着火温度，又可加强燃烧后的混合，促进低反应燃料的燃烬，这样强化了稳燃条件，在烧无烟煤和贫煤的混合煤时。     

低挥发分煤低NO_X燃烧技术研究与开发

我国排放的氮氧化物中,燃煤电站产生的氮氧化物(NOX)占排放总量的比例逐年在增加,控制燃煤电站NOX排放至关重要。本文介绍目前国内燃煤电站主要采用的低NOX燃烧技术,重点通过低挥发分贫煤燃烧过程NOX释放特性的实验研究,提出新一代立体分级低氮燃烧技术,可以有效降低燃贫煤锅炉NOX排放。     

大型锅炉高效低NOx燃烧技术的研究

本文详细分析了NOx生成机理 ,低NOx燃烧器以及炉内空气分级燃烧的机理及其影响因素 ,并对 30 0MW贫煤锅炉高效低NOx燃烧技术进行优化模拟 ,对OFA优化设计作了介绍。为修改制定大型贫煤锅炉NOx排放标准及大型锅炉优化设计与运行提供了科学依据     

汉川电厂引进型300MW机组贫煤锅炉燃烧技术

文章介绍分析了湖北汉川电厂300MW机组贫煤锅炉燃烧技术的特点及其运行实绩,强调指出该技术在我国四角切向燃用贫煤和无烟煤锅炉上可推广应用的前景。     

一维火焰炉中混煤燃烧氮析出特性的试验研究

在一维煤粉燃烧试验台上,对贫煤掺混不同煤种的混煤在一维火焰燃烧过程中氮的析出特性进行了试验研究.结果表明:煤中析出氮主要以NO存在,NO2生成量很少;贫煤掺混不同煤种在相同工况下燃烧时氮释放差别较大,掺配比、氮存在形态对氮析出产物的形式和浓度有较大影响;混煤燃烧氮析出曲线一般具有双峰结构,混煤析出氮与组分单煤的加权平均有一定差异,氮析出量与混煤掺烧比例有关.     

混煤在一维火焰燃烧过程中氮析出特性研究

对贫煤与不同煤种组成的混煤在一维火焰燃烧过程中氮的析出特性进行了试验研究。结果表明:在相同工况下,贫煤掺混不同煤种燃烧时氮的析出特性差别较大,掺配比、氮存在形态对混煤中氮的析出产物形式、浓度有较大影响,在试验基础上找出了混煤燃烧过程中氮的析出规律,对混煤污染物控制,优化燃烧有一定的指导意义     

挥发份燃烧生成NO的试验研究

对铜川贫煤进行了挥发份析出和燃烧试验。通过测取和分析挥发份燃烧后烟气中NO，对铜川贫煤挥发份中氮的赋存及迁移规律进行了探索和研究，研究表明，铜川煤的挥发份中氮的赋存形态至少为2种，随着挥发份燃烧温度的升高，NO浓度峰值的出现时间的向前移动，挥发份燃烧温度上升到1673K以后，虽然有利于热力型NO的生成，但对燃料型NO的形成有一定的抑制作用，研究结果为进一步完善煤燃烧理论，有效控制煤燃烧过程中氮氧化物的生成提供了必要的理论基础。     

粒径对贫煤空气分级NOx排放特性影响的试验研究

采用煤粉燃烧自维持一维试验炉进行了不同煤粉粒径贫煤的单级和多级空气分级燃烧试验,研究了煤粉粒径对煤粉空气分级燃烧NOx排放的影响,探索适用于贫煤空气分级燃烧的煤粉粒径参数和分级级数,以实现较低的NOx排放.结果 表明:粒径影响炉内煤粉颗粒燃烧过程和NOx生成特性,细煤粉颗粒的燃烧速率更快,在炉内易形成还原性气氛,有利于抑制NOx生成和促进已生成的NOx的均相异相还原反应;在深度空气分级燃烧条件下,粒径减小对于降低NOx排放的作用更加显著;采用多级空气分级燃烧能够进一步降低NOx排放量.建议在实际燃用贫煤的锅炉中,采用两级空气分级燃烧和平均粒径为22.78 μm的细煤粉相结合的燃烧技术方案,此时NOx质量浓度可减少27.9％.     

内燃机零部件有限元分析的研究现状与展望

有限元法在内燃机零部件设计中的应用，极大地提高了内燃机零部件的设计水平，缩短了设计周期，提高了设计的可靠性，推动了内燃机工业的发展。论述了有限元技术在内燃机曲轴和连杆等零部件设计中的应用现状及最新发展，并讨论分析了发展趋势。     

396柴油机燃烧系统解析

通过三维仿真,进行396柴油机燃烧过程机理的研究,以明确燃烧系统设计参数对燃烧过程的影响规律,探索微观机制,为大功率柴油机燃烧系统的设计提供理论依据.     

高温台车式加热炉燃烧系统设计

介绍了高温台车式加热炉燃烧系统的设计.该加热炉采用单蓄热式燃烧方式,对燃烧系统的主要组成进行描述并对管路进行详细设计计算.采用该燃烧系统能达到节能减排的效果,为企业创造了良好的经济效益.     

Influence of nozzle design parameters on exhaust gas characteristics in practical-scale flameless hydrogen combustion

Considering the trend toward decarbonization, hydrogen is expected to be used as a fuel in industrial furnace burners. One of the challenges in using hydrogen as a fuel is the increase in thermal-NOx emission compared to hydrocarbon fuel owing to its high flame temperature. This study experimentally evaluated the combustion characteristics of flameless combustion, which is a low-NO_x combustion technology, with hydrogen as a fuel in a practical-scale experimental furnace as well as the effect of nozzle design parameters on the combustion characteristics. Through comparative tests with city gas by considering parameters, such as the fuel gas velocity, combustion air velocity, and air nozzle pitch, the low-NO_x effect of flameless combustion was confirmed in hydrogen combustion with appropriate nozzle design parameters. The optimal nozzle design parameters to achieve this effect differ from those for city gas, and the design guidelines are summarized.     

W火焰锅炉燃用劣质无烟煤的稳燃技术

对燃用韶关地区劣质难燃无烟煤的W火焰锅炉来说，长时间稳定燃烧是个较大的技术难题。介绍了W火焰炉的设计特点和调试期间发生的燃烧不稳现象，提出了针对劣质难燃无烟煤所采取的稳燃技术方法，描述了所达到的稳燃效果，并就燃烧和设计技术的进一步完善化给出了建议。图2表5参5     

Active fuel design—A way to manage the right fuel for HCCI engines

Homogenous charge compression ignition (HCCI) engines feature high thermal efficiency and ultralow emissions compared to gasoline engines. However, unlike SI engines, HCCI combustion does not have a direct way to trigger the in-cylinder combustion. Therefore, gasoline HCCI combustion is facing challenges in the control of ignition and, combustion, and operational range extension. In this paper, an active fuel design concept was proposed to explore a potential pathway to optimize the HCCI engine combustion and broaden its operational range. The active fuel design concept was realized by real time control of dual-fuel (gasoline and n-heptane) port injection, with exhaust gas recirculation (EGR) rate and intake temperature adjusted. It was found that the cylinderto- cylinder variation in HCCI combustion could be effectively reduced by the optimization in fuel injection proportion, and that the rapid transition process from SI to HCCI could be realized. The active fuel design technology could significantly increase the adaptability of HCCI combustion to increased EGR rate and reduced intake temperature. Active fuel design was shown to broaden the operational HCCI load to 9.3 bar indicated mean effective pressure (IMEP). HCCI operation was used by up to 70% of the SI mode load while reducing fuel consumption and nitrogen oxides emissions. Therefore, the active fuel design technology could manage the right fuel for clean engine combustion, and provide a potential pathway for engine fuel diversification and future engine concept.     

直喷式柴油机燃烧室计算机辅助设计

从改进和完善直喷式柴油机燃烧室的设计方法的观点出发,本文提出了直喷式柴油机燃烧室计算机辅助设计的设想,并建立了一部分计算模型,由此得到的计算结果对新型直喷式柴油机燃烧室的设计和试验结果的分析均有一定的帮助。     

Fuel design and management for the control of advanced compression-ignition combustion modes

Due to concerns regarding the greenhouse effect and limitations on carbon dioxide emissions, the possibility of a next-generation combustion mode for internal combustion engines that can simultaneously reduce exhaust emissions and substantially improve thermal efficiency has drawn increasing attention. The most prominent characteristic of new combustion modes, such as Homogenous-Charge Compression-Ignition (HCCI), Stratified-Charge Compression-Ignition (SCCI), and Low-Temperature Combustion (LTC), is the requirement of creating a homogenous mixture or controllable stratified mixture prior to ignition. To this end, a lean fuel/air mixture and/or a controllable high level of exhaust gas recirculation (EGR) are employed to prolong the timescale of the ignition chemistry and port fuel injection or early in-cylinder injection is used to lengthen the mixing period. The mixture then undergoes controlled self-ignition near the top dead center (TDC) position due to the compression effect of the piston’s upward movement. It is worth noting that the entire combustion process lacks a direct method for the control of ignition timing and combustion rate, which are instead controlled primarily by chemical kinetics and, to a lesser extent, by turbulence and mixing. Because of the significant impacts of fuel physical–chemical properties on the ignition and combustion process, fuel design and management has become the most common approach for the control of ignition timing and combustion rate in such advanced combustion modes.This paper summarizes the concepts and methods of fuel design and management and provides an overview of the effects of these strategies on ignition, combustion, and emissions for HCCI, LTC, and SCCI engines, respectively. From part 2 to part 4, the paper focuses on the effect of fuel design on HCCI combustion. A fuel index suitable for describing ignition characteristic under HCCI operating conditions is first introduced. Next, the proposed fuel design concept is described, including principles and main methodologies. Strategies based on the fuel design concept (including fuel additives, fuel blending, and dual-fuel technology) are discussed for primary reference fuels (PRF), alternative fuels, and practical gasoline and diesel fuels. Additionally, the effects of real-time fuel design on HCCI combustion fueled with PRFs and dimethyl ether/liquefied petroleum gas (DME–LPG) are evaluated. Diesel HCCI combustion has suffered from difficulties in homogenous mixture formation and an excessively high combustion rate. Therefore, LTC, which concentrates on local combustion temperature and a balance of mixture formation timescale and ignition timescale, has been proposed by many researchers. In Part 5, this paper provides an overview of the major points and research progress of LTC, with a preliminary discussion of the fundamental importance of fuel properties and fuel design strategy on the LTC process and emissions. Due to the stratification strategy has the capable of extending the HCCI operation range to higher loads, SCCI combustion, which incorporates HCCI combustion into a traditional combustion mode, has the potential to be used in commercial engines. Thus, this paper discusses the principles and control strategies of fuel design and management and also summarizes recent progress and future trends. The effect of fuel design and management on SCCI combustion is assessed for high cetane number fuels and high octane number fuels as well as the in SCCI combustion of gasoline–diesel dual-fuel and blends.     

增压锅炉烟气发生器燃烧流场数值模拟与结构优化

本文采用数值模拟方法,对增压锅炉烟气发生器设计结构方案的燃烧流场进行数值分析,分析内部的流动规律以及原始设计中存在的问题。通过改进烟气发生器的几何结构,得出更加合理的流场分布,从而指导它的结构优化设计。数值计算结果表明,所采取的改进措施的效果明显,达到了优化增压锅炉烟气发生器燃烧段设计方案的主要目的。     

进气道和燃烧室形状对火花点火发动机燃烧过程影响的研究

本文针对ＣＡ６１０２发动机燃烧慢、循环变动率偏大等问题，对进气道和燃烧室进行了改进。研究了不同进气道和燃烧结构（六种匹配方案）对燃烧过程和性能的影响，发现涡流比和性能之间无单调的相关关系，与燃烧期之间存在二次抛物线型的逆变相关关系，ＣＡ６１０２发动机合适的涡流比在０．９左右，燃烧室设计因素中火花塞的位置对燃烧过程和性能影响最大，火花塞靠近中心布置方案同原机相比，最低燃油消耗率降低了４．１％，最大扭