文丘利油燃烧器内外部等温流场的数值模拟

针对文丘利油燃烧器流场数值模拟存在的特殊性,提出了一种分析模型和处理方法。通过数值模拟结果与试验数据的对比分析,表明该文建立的模型及处理方法是可行的,并据此进一步对某舰船锅炉文丘利油燃烧器的内外部等温流场进行了预测分析。     

带入口旋流器的文丘利油燃烧器出口热态流场的数值模拟

针对带入口旋流器的新型文丘利油燃烧器出口流动燃烧的特点，建立了相应的数学物理模型和数值算法。在数值模拟一、二次风道内部流动及出口等温流场的基础上，对新型油燃烧器出口的热态流场进行了数值模拟，并与未装设入口旋流器的文丘利油燃烧器出口冷热态模拟结果进行了对比分析。模拟结果为该型油燃烧器的进一步改进设计、运行及布置提供了重要依据。图9表1参10     

单只文丘利油燃烧器出口气液两相流动与燃烧的数值模拟

针对选配文丘利型油燃烧器的燃油锅炉中液雾燃烧的特点,提出了一种数值模拟分析模型及处理方法,据此数值模拟了某单只文丘利油燃烧器出口的气液两相流动与燃烧,给出了流中的速度场,温度场以及浓度场的分布信息,这些结论可为该型燃烧油锅炉的进一步设计和运行以及燃烧室的布置提供有益的依据。     

RPY型燃烧器介绍

由703研究所设计、辽河油田和哈尔滨龙江锅炉燃烧器厂参与研制的RPY型燃烧器于今年3月26日在辽河油田通过技术鉴定。RPY型燃烧器是由文丘利调风器,Y型喷油器(或机械雾化喷油器)及天然气喷枪所组成。助燃空气由鼓风机送入风箱,沿着文丘利喷管轴向流动进入炉膛,在风口出口处装有出口旋流器,提供一定量的旋转一次风,形成中心回流区,以保证着火稳定。在结构上还保证有一定的中心风供入油雾锥的根部,以促进燃烧完全。Y型喷油器以蒸汽作为雾化介质,雾化细,耗汽量少,适于有蒸汽压力大于4kg/cm~2的锅炉房。机械雾化     

文兵利管内外流场的数值计算及实验研究

通过对文丘利管内外流场的数值计算，从理论上分析了文丘利管本身结构参数，对其内部流场以及其本身对风道流场的影响，实验证了影响性能的关系因素。计算结果和冷态模实验结果吻合良好。     

带入口旋流器的文丘利调风器的内外部等温流场的数值模拟

针对带入口旋流器的新型文丘利调风器流场的数值模拟,提出了一种分析模型和处理方法。通过模拟结果与试验数据的对比分析,表明本文作者建立的模型及处理方法是成功的,据此进一步对某船用锅炉带入口旋流器的新型文丘利调风器的内外部等温流场进行了预测分析。     

文丘利管内外流场的数值计算及实验研究

通过对文丘利管内外流场的数值计算,从理论上分析了文丘利管本身结构参数（收缩比β,收缩角θ１,扩张角θ２）对其内部流场以及其本身对风道流场的影响,实验验证了影响性能的关键因素。计算结果和冷态模化实验结果吻合良好。     

用文丘利管测量高压汽水两相流体的流量及干度

本文从分相动量模型出发,提出了一个用文丘利管测量汽液两相流流量及干度的计算关系式,并以高压汽水为工质进行了详细的试验研究.在压力36.7～132bar、干度0.075～0.992、管道内径21mm、文丘利管的β值为0.5524的范围内,流量和干度的均方根误差分别为±2.377%、±4.993%。     

利用双节流元件测量两相流干度

以经典均相流和分相流模型为基础 ,推导了一个理想条件下直接测量两相流干度的公式 ,分析了公式的适用范围。设计了水平孔板和垂直下降文丘利管串联组合的实验装置 ,并以空气和水为工质进行了实验研究。实验研究表明 ,在环状流区垂直下降文丘利管的压降特性更接近于均相流模型的计算结果。这种方法在文中给定的干度范围内测量的相对误差小于± 10 %。     

非标准文氏管气固两相流阻力特性的研究

通过试验测量不同节流比的非标准文丘利管在单相流和不同浓度煤粉流中的压差,得到文氏管相应的阻力系数ζ0和ζμ同时计算出阻力比例系数Kj,分析节流比、煤粉浓度,煤种等因素对ζμ和Kj影响,得出ζμ、Kj与影响因素的关系,并将ζμ与m, μ的关系拟合成关系式。     

某电厂220t/h锅炉煤粉燃烧器改造设计方案

为提高某电厂220t/h煤粉锅炉燃烧器低负荷稳燃能力，拟采用浓淡燃烧技术对该炉燃烧器进行改造；下层燃烧器采用水平浓淡燃烧器，上层燃烧器采用上下浓淡燃烧器；为保证低负荷时的主蒸汽温度，上层燃烧器为摆动式燃烧器。     

采用旋流拱顶燃烧器的W型锅炉炉内流动特性

采用旋流燃烧器,可以强化燃烧器出口煤粉气流的着火,配合采用燃烧器内部分级燃烧方式后,也有利于降低污染气体的排放。但采用旋流燃烧器后,由于W型锅炉燃烧的特殊性,给锅炉的设计和运行带来了新的情况,如对旋流燃烧器在W型锅炉拱顶采用旋流燃烧器后炉内的空气动力特性不能很好得到掌握,不但得不到旋流燃烧器所带来的优点,还会引起很多问题。本文对采用旋流燃烧器的W型锅炉的炉内多相流动特性进行分析,并与相应的采用直流燃烧器的W型锅炉进行对比,指出在采用直流燃烧器的W型锅炉设计中常采用的参数在采用旋流燃烧器时可能会出现的问题,并提出了改进的方法。     

低热值煤层气燃烧器的数值模拟

对一种低热值煤层气燃烧器进行了全尺寸的三维燃烧数值模拟研究,预测了燃烧器出口的流场、温度和组分分布情况,并考察了不同热负荷和不同喷口形式对燃烧器性能的影响。结果表明该燃烧器具有较宽的负荷调节能力,渐缩喷口燃烧器燃烧温度最高且射流刚性好,50%~100%热负荷内渐扩喷口燃烧器燃烧性能最佳,25%热负荷下渐缩喷口燃烧器燃烧性能最佳。模拟结果对该燃烧器的进一步优化设计有一定的指导意义。     

煤粉炉微油点火燃烧器设计

介绍了对一台容量为50WM锅炉的煤粉燃烧器的改造过程。根据燃烧理论,将原来的煤粉燃烧器改造成了微油点火燃烧器,并介绍了燃烧器的设计思想,以及小油枪的计算方法。微油点火燃烧器采用了分级燃烧方式和二次风冷却技术,能够很好起到稳燃和冷却的作用。改造后的效果表明该燃烧器锅炉启停速度快,燃烧稳定,节约燃油,降低了生产成本。     

Optimization of producer gas fired premixed burner

Much work is reported in the literature pertaining to premixed burners using hydrocarbon fuels. However, very little work is available on similar burners using producer gas as a fuel. The present work aims at testing and optimization of a premixed burner with producer gas as a fuel.A burner of 150 kW capacity is used in the experimental investigations. The burner is of concentric tube type fully premixed in which air is supplied through central pipe and gas is supplied through annular passage. Swirl vane is provided to air and gas for thorough mixing. The bluff body is provided for flame stabilization. The premixed burner was tested on open core throat-less down draft gasifier for flame quality. A stable and uniform flame was observed with this premixed burner. Thereafter, an instrumented test set up to evaluate burner performance was installed on an open core gasifier. The burner was experimentally optimized for size and location of bluff body and flammability limits. The burner was optimized by using bluff bodies of 46, 61, 73, 80, 85, 98, 110 and 122 mm diameters. The burner was operated in batch operation of 6–8 h for optimization of various parameters. The experiment reveled that the uniform and high-temperature premixed flame was observed at conventional bluff body having blockage ratio of 0.65. The flammability limits for producer gas fired burner was established in the range of 40–55.     

Performance and Emission Analysis of a Novel Porous Radiant Burner for Domestic Cooking Application

Present study focuses on the performance and emission analysis of a novel porous radiant burner for domestic cooking application using liquefied petroleum gas (LPG) as fuel. The porous radiant burner (PRB) used here is a novel ceramic porous radiant burner which is designed and developed in the University laboratory for this present study. Two kinds of PRBs as circular porous radiant burner and square porous radiant burner have been developed and hence the thermal efficiency and emission analysis of these burners are tested for their performance. The test results are very encouraging as the thermal efficiency of the circular porous radiant burner and square porous radiant burner are much higher as compared to the conventional metallic burners or other types of burners. The emission characteristic also shows that the emission of CO and NOx values are much lesser than the conventional burner and are well within the world health organization standard. The experimental setup used here is a flexible one that contains PRBs, LPG cylinder, K- type thermocouple, data acquisition system, flue gas analyzer, Infrared camera and a computer. The maximum thermal efficiency obtained in that test for the PRB is about 72% which indicates its bright future prospect.     

Combustion characteristics of a heat-recirculating ceramic burner using a low-calorific-fuel

A new type of the heat recirculating burner was constructed and its combustion characteristics during steady low-calorific-fuel/air combustion were investigated. Flammability limits of the burner were measured by experiments, and longitudinal temperature distributions of air and burned gas flowing in the passes of the burner were determined by means of both experimental measurements and numerical simulations. Using the heat recirculation rate and the thermal efficiency as criteria for the performance of the burner, the optimal design of the burner was examined in terms of a chemical parameter (the equivalence ratio), a fluid-mechanical parameter (the Reynolds number) and a geometrical parameter (the number of passes).     

富集型燃烧器及多重富集型燃烧器研究

通过对煤粉稳燃燃烧器的研制过程 ,提出了新的煤粉燃烧器的着火稳燃机理 :组织煤粉气流的浓淡分流 ,组织浓 (小 )股煤粉气流的急拐弯 ,让气粉分离 ,煤粉射入高温回流区 ,在这里滞止增浓 ,升温着火 ,形成小火焰 ,并用它点燃整个一次风煤粉火焰 ,即小火点大火的机理。以此着火稳燃机理为指导 ,成功地开发了富集型燃烧器及多重富集型燃烧器 ,已在 1 0 0～ 2 0 0MW机组上得到广泛应用。由于它的喷口小 ,预期多重富集型燃烧器会受到电厂更大的欢迎。     

惯性浓淡旋流燃烧器的原理及其在50t_h锅炉上的应用

在径向浓淡旋流煤粉燃烧器的基础上,本文提出了一种新型燃烧器－惯性浓淡旋流煤粉燃烧器,即在燃烧器一次风通道中加入煤粉浓缩器,并将其置于燃烧器喷口较近的位置,一次风粉经过煤粉浓缩器后,形成了由燃烧器中心向外煤粉浓度由高向低的分布趋势,依靠煤粉颗粒的惯性,将这种分布趋势一直保持到燃烧器出口。针对一台燃用烟煤的５０ｔ／ｈ煤粉炉的特点,给出了该燃烧器的布置,介绍了改造前后的运行情况。     

A fibre‐mat catalytic burner for the heating system of PVC tiles

This study aims to develop the low‐temperature catalytic burner using Al₂O₃ fibre and Pt catalyst as a substrate and an active material, respectively, and then to apply it to the heating system of PVC tiles. Three types of fibre‐mat catalytic burners—natural diffusion catalytic burner, forced diffusion catalytic burner and premixed catalytic burner—were tested. For the natural diffusion catalytic burner, the combustion efficiency was significantly affected by the installation method. Its combustion efficiency was above 99.5% when it was placed vertically and upward, whereas the combustion efficiency rapidly deteriorated to less than 80% when it was installed in downward position. When the forced diffusion combustion mode was employed, the combustion efficiency of the fibre‐mat catalytic burner was successively improved over 99.5%. The optimal operation condition of the premixed fibre‐mat catalytic burner was obtained when the excess air ratio is 4.3 and the heat load is 3.0 kcal h^?1 cm^?2. The heat load of the premixed catalytic burner was found to be twice as much as those of the natural and forced diffusion catalytic burner, meaning that the size of the catalytic burner can be reduced to its half if the premixed catalytic burner is used. We also performed the field test of the fibre‐mat catalytic burner in the heating system of the PVC tiles. The combustion efficiency of the catalytic burners appeared to be satisfactory, above 99.5%, and the energy saving by replacing the existing electrical heaters with the fibre‐mat catalytic burners were shown to be 27.7%. Copyright © 2002 John Wiley & Sons, Ltd.