乳化燃油燃烧值的实验测定与燃烧性能的研究

本文对含水量为０％，１０％，２０％，３０％和４０％的乳化燃油的燃烧值进行了实验研究与测定，并对乳化燃油的燃烧性能进行了理论研究，提出“微爆分子解聚”模型来解释乳化燃油燃烧节能的机理。     

鼓风参数对高炉直吹管内煤粉燃烧过程的影响

通过建立数学模型,在Fluent软件的基础上结合自编程序,对不同鼓风参数下高炉喷吹煤粉的燃烧过程进行模拟,主要考虑鼓风温度、鼓风富氧率和水分对煤粉燃尽率和气体组分分布的影响。模型中包含气固两相流动,煤粉与O2、CO2及H2O的异相反应,并对模型进行了验证。模拟结果表明：提高鼓风温度和富氧率可以更好地提高煤粉在高炉直吹管内燃尽率,鼓风水分含量对煤粉燃尽率影响不大,促使温度场提前。     

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。     

油页岩掺混煤的燃烧性能与排放性能

对油页岩和煤进行了元素分析和工业分析,并利用热重-红外联用仪对油页岩与煤不同比例的掺混物进行了燃烧性能实验和排放性能实验.结果表明:油页岩燃烧非常剧烈,并具有集中析出的特性;在油页岩中掺混一定比例的煤有助于油页岩的平稳燃烧和充分燃烧,并降低其固定碳燃烧阶段的活化能,其燃烧过程排放的CO、CO2会增加,NOx和SO2排放变化不明显.     

分离燃尽风对贫煤锅炉CO和H2S生成特性的影响

以低氮燃烧改造后的某330 MW四角切圆贫煤锅炉为研究对象,采用数值模拟研究了300 MW负荷下分离燃尽风率对炉内燃烧速度场、温度场、CO体积分数场、O2体积分数场、H2S体积分数场及炉膛出口参数的影响,并将模拟结果与试验结果进行对比分析.结果 表明:分离燃尽风率对锅炉燃烧特性以及CO、H2S的生成特性具有重要影响;随...     

水分对煤的燃烧及传热的影响

分析了水分在煤中存在的形式,从燃烧动力学角度讨论了水分对煤的燃烧及传热过程的影响。     

煤的脉动燃烧模型

煤在Ｒｉｊｋｅ（里克）管型燃烧器中脉动燃烧是一个很有发展前途的技术，文章作了简要的介绍，高的燃烧效率，高的换热效率和低的环境污染是其３大优点，且于锅炉热效率可望提高５％～１０％和使排烟几乎透明。文章提出了一个理论模型，该模型能对观察到的许多试验现象给出合理的解释。它不仅有说服力地说明了煤床放在燃烧器下半段才有可能起振，且在下Ｌ／４处声振最强的原因，也说明了无平均流速时振不起的起来和声振强度随鼓风与     

调制喷油模式对柴油HCCI燃烧性能和排放的影响

基于多脉冲喷射模式调制的电控开发系统和对柴油HCCI燃烧过程的认识,设计了一系列的典型调制多脉冲喷油模式,包括交错式(SM)、驼峰式(HM)、均衡式(EM)和递增式(PIM)．分别进行了4次多脉冲、5次多脉冲和6次多脉冲调制喷油模式的HCCI发动机试验研究．试验结果表明,柴油HCCI燃烧对调制喷油模式极其敏感,基于调制喷油模式的柴油HCCI燃烧均能达到超低的NOx排放(小于0．82 g／(kW·h))和较低的碳烟排放(小于0．5 BSU)．调制喷油模式的优化,可以使柴油HCCI发动机获得更高的功率输出,拓展其运行的工况范围．     

切圆锅炉煤粉燃烧过程的数值研究与工业测试

为了了解额定蒸发量为130t/h的煤粉锅炉热效率偏低,水冷壁常发生结焦现象的原因,对锅炉进行了冷态空气动力场以及热工综合测试,并应用κ－ε－g气相湍流燃烧模型与煤的双辉反应热解模型对炉流动,燃烧以及传热过程进行了数值计算。冷态与热态的数值计算结果与测试结果相吻合。其结果表明：炉膛内空气过纱数偏小导致锅炉热效率偏低;同一标高的4个燃烧器喷出的气流速度相差较大,使气流在人形成的实际切圆偏离炉膛中央,导致火焰刷壁,水冷壁结焦。     

Three dimensional modeling of pulverized coal combustion in a 600 MW corner fired boiler

IntroductionThe developments relative to coal combustion havebeen performed into a general purpose 3D code namedESTET under quality assurance, and used to modelcomplex turbulent reactive flows. In the case ofindustrial boilers we can assume a no-slip conditionbetween gas and particles which is the case for the mostpart of the furnace, except possibly in the near field ofthe burners. With such an assumption, the equations for apafticle-gas fixture with a mean density can be written.The combu…     

Study of the flue gas characteristics and gasification reaction of pulverized coal combustion in O2/CO2/H2O atmosphere

The impacts of O₂ and H₂O on the combustion characteristics of pulverized coal in O₂/CO₂/H₂O atmosphere were studied. The gasification reaction ratio was calculated from the components of flue gas. The competition exists between C-CO₂ and C-H₂O reactions under rich CO₂ atmosphere. At various H₂O concentrations, the differences were found in generation amounts of CO and H₂ in flue gas. At O₂ concentrations <10%, C-CO₂ reaction decreased while C-H₂O reaction increased with increasing H₂O concentration; while at O₂ concentration >30%, H₂O showed no obvious specific patterns of effects. The gasification ratio was reduced as coal ranks increase.     

石煤燃烧的汞排放特性研究

我国南方煤炭资源相对贫乏,而石煤的资源相当丰富,为了综合利用石煤资源,利用1MW循环流化床试验台进行了石煤和烟煤的混燃试验,对底渣、烟气和飞灰中的Hg的含量进行了详细的分析,得出了石煤和烟煤混燃的底渣、烟气和飞灰中汞的分布特性,为石煤的进一步推广应用提供依据。     

410t/h煤粉炉乏气送粉改造降低NO_x排放的试验研究

针对某电厂410 t/h煤粉炉在300 t/h以上高负荷下运行时NOx排放无法达标的问题,提出了将原中储式温风送粉系统改造为乏气送粉系统,技术方案为排粉风机出来的乏气全部送入一次风管道,直接采用乏气作为送粉介质输送煤粉,避免乏气直接送入炉膛造成的局部富氧气氛,从而有效抑制乏气中的煤粉燃烧NOx生成量。试验及调试结果表明,采用乏气送粉改造后,锅炉燃烧稳定、热效率未受影响,NOx排放降低到100 mg/m3以下(折算到氧量6%)。     

电站煤粉锅炉火焰监测与燃烧诊断优化控制研究

为保证锅炉安全运行,必须进行切实有效的火焰监测和燃烧诊断措施。基于火焰图像处理技术的电站锅炉火焰监测和燃烧诊断优化控制系统,能够实时在线地监视火焰图像,对火焰图像特征进行分析,对炉内温度场进行重建,同时进行燃烧稳定性、经济性和清洁性的判断,提出运行建议,并利用炉内辐射能信号响应灵敏、迅速的特点将其作为负荷控制的前馈信号,接入DCS控制逻辑中以提高锅炉的负荷响应能力和抗干扰能力。     

COREX熔化气化炉填充床内未燃煤粉行为的实验研究

通过建立热态模型,利用石蜡模拟矿石,玉米粒子模拟焦炭和块煤,煤粉模拟未燃煤粉,用于研究COREX熔化气化炉填充床内的未燃煤粉.结果显示,在正常生产和风口回旋区塌料两种炉况下,填充床中的未燃煤粉有弥散和聚集两种分布形式;聚集形式的未燃煤粉从填充床中心向边缘发展.最后,结合本实验结果和前人研究成果提出了关于COREX的生产...     

煤气化置换燃烧分离CO2模拟分析与研究

基于Aspen plus软件,根据Gibbs自由能最小化原理对煤气化置换燃烧过程进行热力学平衡分析.对徐州烟煤以NiO作为载氧体,研究在常压时燃料反应器温度、水煤比对燃料反应器气体产率和载氧体循环倍率的影响.结果表明燃料反应器温度的降低有利于煤气化产物的氧化;水蒸气用量较少时可得到较高浓度的CO2燃料反应器温度的降低和水蒸气用量的减少将减少载氧体循环倍率.     

Comparison of staged combustion properties between bituminous coals and a low-rank coal; Fiber-shaped crystallized carbon formation,NOx emission and coal burnout properties at very high temperature

Previously, we developed a new-concept for a drop-tube furnace in order to investigate staged combustion properties for pulverized coals. Two high-temperature electric furnaces were connected in series. Coal was burnt under fuel-rich conditions in the first furnace, then, staged air was supplied at the connection between the two furnaces. In the present study, we investigated influence of burning temperature on NOx emission and combustion efficiency by using the furnace. The influence of the temperature differed between hv-bituminous coals and a sub-bituminous coal. For the hv-bituminous coals, combustion efficiency was improved when burning temperature in the fuel-rich region rose. When combustion efficiency was improved, NOx emission decreased. The NOx reduction reaction in the fuel-rich region was promoted by increasing the burning temperature in this region. On the other hand, NOx emission increased for the sub-bituminous coal when the temperature was higher than 1800 K. Usually, combustion efficiency was increased with burning temperature. However, combustion efficiency lowered for the sub-bituminous coal when burning temperature was higher than 1900 K. We observed the ash obtained by this temperature condition using Scanning Electron Microscope (SEM) and, Transmission Electron Microscope (TEM) and observed fiber shaped carbon. The difference in NOx properties was derived as a difference of hydrocarbon concentration. For low-rank coals (sub-bituminous or lignite), the hydrocarbon formation rate was smaller than that for hv-bituminous coals. When the hydrocarbon contribution to the NOx reduction reaction was large, NOx emission decreased with increasing burning temperature; however, hydrocarbon content in volatile matter was small for low-rank coals.     

不同采矿深度准东煤物化特性和燃烧性能研究

选取天池能源浅层和深层煤样进行研究,以大同烟煤作为对比,了解采矿深度对煤质及燃烧特性的影响,为准东煤的勘探和燃烧提供必要的理论依据。研究发现,随着采矿深度的增加,煤中水分减少、灰分降低、发热量增加、含硫量减少,煤质更加接近烟煤;煤灰中Fe2O3明显减少,煤的结渣趋势减轻;煤的着火温度略有降低,燃烧速率提高,燃烧特性变好。与大同烟煤相比,准东煤高水分、低发热量、低氮含量,燃烧时着火温度显著降低且燃烧速率低。