热风炉提高风温的几点浅见

综述了热风炉提高风温的主要途径：采用空煤气预热和高效能陶瓷燃烧器技术提高理论燃烧温度和拱顶温度;增大单位体积格砖的换热面积和采用均匀配气技术加强蓄热室内的热交换;同时在热风炉的不同部位选用不同材质的耐火材料,实现良好的保温效果;在此基础上适当缩短送风周期时间,并采用合理的操作制度。适当评价了各种技术对提高风温的效果。     

新型高效蓄热式燃烧系统设计研究

采用约束设计法,通过蓄热室烟气回收获得最大净效益时各参数的优化,研究设计出一套新型高效蓄热式燃烧系统。该燃烧系统燃烧能力为1．0MW,燃料采用焦炉煤气,蓄热体采用陶瓷球,燃烧器换向时间73S,烟气出口平均温度为110℃,预热空气出口平均温度为1110℃,蓄热室热效率和温度效率分别达到90．8％和92．47％。燃烧系统采用煤气和空气双预热,煤气、空气射流卷吸炉瞠内的烟气,实现低氧和低NOx燃烧。它对于开发适合我国国情的高效蓄热式燃烧系统具有重要意义。     

2014年5月份全球制造业PMI为52.2%

从中国物流与采购联合会获悉,5月份,全球制造业PMI为52.2%,连续18个月运行在50%以上,环比上升0.3个百分点,表明全球制造业活动增速较上月有所加快。主要分项指标中,生产指数为53.5%,比上月调整后的52.9%回升0.6个百分点,连续19个月运行在50%以上,表明全球制造业生产活动增速较上月有所加快;新订单指数结束了连续回落走势,达到53.1%,较上月调整后的52．6％上升0．5个百分点;就业指数达到50．9％,较上月的51．5％回落0．6个百分点;购进价格指数为53．0％,较上月调整后的51．2％上升1．8个百分点,创近三个月新高。     

低NO_x燃烧器锅炉的优化燃烧

OptimizingCombustioninBoilerswithLow-NOxBurners低NOx燃烧器锅炉达到燃烧优化的实际方面是什么？根据以往在许多台电站锅炉调试中获得的经验，低NOx燃烧器的优化燃烧需要满足下述10条前提条件：（1）炉膛出口烟气必须为氧化性气氛，通常应具有3％的过剩氧量。（2）燃料细度必须满足通过200目筛子的燃料量大于70％，而在50目筛子上的燃料剩余量应小于0．5％。（3）每只燃烧器之间的燃料分配偏差必须控制在上5％至±10％的范围内。（4）一次风量（PA）必须满足一定的风煤比，通常在较高的磨煤机出力下，一次风中空气与燃料的质量比应…     

转炉污泥干法脱硫新技术应用

采用转炉污泥取代铸铁屑配制焦炉煤气脱硫剂，转炉污泥与稻壳体积配比为１：２，水分３０％－４０％，ＰＨ值８－１０，经过生产实践证明，脱硫效率达到９８．９－９９．８％，既降低了煤气生产成本，减轻工人劳动强度，又提高了民用煤气质量，具有可观的环境效益与经济效益。     

风机、水泵节能潜力大

据第三次工业普查资料：我国风机、水泵的设备效率平均为75％，比国外低10个百分点；系统实际运行效率更低，仅为3O－40％，比发达国家低15－ZO个百分点，节约的潜力很大。我国风机、水泵设备装机总功率已达1．59亿千瓦（其中风机O．49亿千瓦，水泵1．1亿千瓦，年总耗电量3200亿千瓦时，约占当年全国电力消耗总量的1／3以上，占工业用电量的40％。专家的估算，如采用简易节电技术进行一般更新改造，节电率可达10％，一年就可节电32O亿千瓦时；如果采用先进的调速节电技术进行系统改造，节电率可达3O－50％，年节电可达1100亿千瓦时，社会…     

我省工业生产增速回落

1至7月，我省全部国有及年产品销售收入500万元以上非国有独立核算工业企业（简称规模以上工业，下同），完成工业增加值562．92亿元，比去年同期增长6．7％，增速比一季度和上半年分别回落11．5个和1．8个百分点，增速呈继续回落态势。其中7月份完成增加值77．69亿元，比去年同月下降2．7％，增幅比上月回落3．3个百分点，主要原因是烟草制品业增加值当月同比下降19．6％。1至7月工业生产呈现以下特点：     

海外文献速递

采用装于炉顶的平焰烧嘴可使烧结机的燃料消耗节约２／３。介绍的平焰烧嘴具有５通道喷口。中心通道以扇形气流通入煤气；周围３层通入煤气，为不同方向的旋转气流；最外围通道可当采用低热值煤气且要求大功率时补充通入煤气。烧嘴性能如下：额定天然气耗量２２m３／h；烧嘴前煤气压力１２５０Pa；空气压力１７５Pa；空气过剩系数１．８；最大最小能力比２５０／５０kW。烧嘴可在任意空气过剩条件下保持火焰稳定，并得到均匀的炉温分布。由于分５段供入空气和煤气，使烟气中NOX含量较低。烧嘴可实行自动点火。图３参４[郭伯伟摘]WZ００…     

直流式低热值煤气燃烧器稳燃特性研究

对常规直流燃烧器和锥形半角不同的扩口直流燃烧器进行了低热值煤气的着火和稳燃试验。研究发现:直流燃烧器内径小于8 mm时,其淬熄作用严重影响火焰稳定;提高H2浓度可以改善低热值煤气的稳燃特性;对于低热值煤气,扩口直流燃烧器的稳燃性能优于常规直流燃烧器;扩口直流燃烧器的锥形半角大于10°时,可产生双点火环,提高脱火极限。     

生物质合成气的化学当量比调整

针对生物质气化气中硫化物少、V（H2／CO）低和V（CO2）高的特点，采用气化炉内铁系高温变换催化剂和气化炉外钛促进的钴钼耐硫催化剂进行水煤气变换调整H2／CO比，添加部分沼气重整过量CO2，对生物质合成气化学当量比调整进行了实验研究。结果表明：气化炉内铁系催化剂调整效果不明显；在高温低硫的生物质气化气中，钛促进的钴钼耐硫催化剂具有较高的变换活性，CO转化率达到80％以上，合成气H2／CO比在1-8范围内可调；在V（CH4，CO2）=1、常压、750℃和镍基催化剂作用下沼气重整过量CO2，制备出宽V（H2／CO）、V（CO2）和V（CH4）均低于5％（摩尔百分比）的合成气；通过水煤气变换过程结合沼气重整过程，可依据目的产物合成的要求，制备合适化学当量比、高碳转化率的生物质合成气。     

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.     

燃气燃烧器燃烧特性的数值模拟

运用Fluent软件对40 t/h锅炉用燃气燃烧器进行三维数值模拟,研究进风量对燃烧器性能及污染物NOx排放特性的影响。结果表明:合适的进风量是保证燃烧器稳定燃烧的重要条件,也是减少NOx排放的关键因素。数值模拟的计算结果为燃烧器优化设计、改造提供了参考依据。     

Primary air entrainment characteristics for a self-aspirating burner: Model and experiments

Experimental and theoretical investigations of primary air entrainment characteristics of a self-aspirating burner are presented. Emphasis was made on experiments, which were performed using both hot and cold tests; and a correlation between them is proposed. The level of primary air entrainment is measured using an oxygen sensor and a particle image velocimetry system. Experimental results are used to validate the predicted ones, which are obtained by constructing a theoretical model basing on simple momentum and energy conservation principles. It is found that the model predictions agree with the experimental data for a similar system. Primary air entrainment is a function of fuel gas flow rate, fuel gas type, injector geometry, mixing tube geometry, and burner port geometry. The level of primary air entrainment increases with increasing momentum rate of the fuel gas. The hot test gives about a 22 percentage point (37% relative) lower PA value than that of the cold test because of the preheating effect caused by combustion. A first correlation between the hot test and the cold one for primary air entrainment is proposed. It is recommended that the preheating effect caused by combustion in a self-aspirating burner not be neglected when designing the burner.     

Investigation of the structural and reactants properties on the thermal characteristics of a premixed porous burner

Porous burners offer attractive features such as competitive combustion efficiency, high power ranges, and lower pollutant emissions. In the present study, the thermal characteristics of a porous burner are numerically investigated for a range of operating conditions and design specifications within a practical range. The premixed flame propagation of a methane/air mixture in a ceramic porous medium is simulated through an unsteady, one-dimensional model. The combustion process is modeled using a suitable single-step chemical kinetics. The reaction location is not predetermined, thus the flame is allowed to float within the solid matrix or to run off from either side of the porous medium. The numerical results indicate that flame stability and thermal characteristics of the burner are strongly dependent on the inlet mixture specifications and the solid matrix structural properties. For a fixed value of the inlet firing rate, the combustion products temperature will increase by an increase in the inlet gas temperature, an increase in the matrix porosity, or by a decrease of the matrix pore density. Among the geometrical properties, the burner length has virtually no effect on the burner performance. An increase in the solid matrix porosity or burner firing rate will increase the efficiency of the preheating zone, while increasing the inlet gas temperature or matrix pore density will cause a reduction in this efficiency. Simulation results also suggest that in order to prevent flame blow-out or flash-back, critical values of the burner settings and design parameters must be avoided.     

小型部分预混燃烧器在PNG和LNG下的离焰和黄焰燃烧特性研究

设计了一台功率为1.5kW的小型部分预混燃烧器,其中燃烧器头部材质分别为铸铁和铜铝。通过改变燃气和空气预混比例,实验测试了不同PNG和LNG下燃烧器的离焰和黄焰特性,结合燃烧器头部温度变化规律,分析了在天然气置换后部分预混燃烧器的燃烧特性。实验发现:在发生黄焰时,铜铝材质拟合线性斜率分布在-6.2~-18.6,铸铁材质分布在-4.6~-9.0,在发生离焰时,铜铝材质拟合曲线曲率分布在1.3~2.7,铸铁材质分布在1.1~3.3,铜铝材质头部温度波动大,而铸铁材质保持相对平缓的温度变化趋势;发生离焰时,在高火孔热强度下,LNG引射的空气量波动小,燃烧器头部温度基本不变,PNG引射的空气量下降,火焰根部温度出现上升;黄焰发生时,LNG的引射空气量是PNG的1.2倍左右,引入过多的室内空气,导致燃烧器头部、火焰根部的温度降低。     

Increasing the efficiency of radiant burners by using polymer membranes

Gas-fired radiant burners are used to convert fuel chemical energy into radiation energy for various applications. The radiation output of a radiant burner largely depends on the temperature of the combustion flame. In fact, the radiation output and, thus, the radiant efficiency increase to a great extent with flame temperature. Oxygen-enriched combustion can increase the flame temperature without increasing fuel cost. However, it has not been widely applied because of the high cost of oxygen production. In the present work, oxygen-enriched combustion of natural gas in porous radiant burners was studied. The oxygen-enriched air was produced passively, using polymer membranes. The membranes were shown to be an effective means of obtaining an oxygen-enriched environment for gas combustion in the radiant burners. Two different porous radiant burners were used in this study. One is a reticulated ceramic burner and the other is a ceramic fibre burner. The experimental results showed that the radiation output and the radiant efficiency of these burners increased markedly with rising oxygen concentrations in the combustion air. Also investigated were the effects of oxygen enrichment on combustion mode, and flame stability on the porous media.     

Experimental assessment of the combustion performance of an oven burner operated on pipeline natural gas mixed with hydrogen

With the increasing need to reduce greenhouse gas emission and adopt sustainability in combustion systems, injection of renewable gases into the pipeline natural gas is of great interest. Due to high specific energy density and various potential sources, hydrogen is a competitive energy carrier and a promising gaseous fuel to replace natural gas in the future. To test the end use impact of hydrogen injection into the natural gas pipeline infrastructure, the present study has been carried out to evaluate the fuel interchangeability between hydrogen and natural gas in a residential commercial oven burner. Various combustion performance characteristics were evaluated, including flashback limits, ignition performance, flame characteristics, combustion noise, burner temperature and emissions (NO, NO₂, N₂O, CO, UHC, NH₃). Primary air entrainment process was also investigated. Several correlations for predicting air entrainment were compared and evaluated for accuracy based on the measured fuel/air concentration results in the burner. The results indicate that 25% (by volume) hydrogen can be added to natural gas without significant impacts. Above this amount, flashback in the burner tube is the limiting factor. Hydrogen addition has minimal impact on NO_X emission while expectedly decreasing CO emissions. As the amount of hydrogen increases in the fuel, the ability of the fuel to entrain primary air decreases.     

Experimental simulation on the integration of solid oxide fuel cell and micro-turbine generation system

Solid oxide fuel cell (SOFC) is characterized in high performance and high temperature exhaust, and it has potential to reach 70% efficiency if combined with gas turbine engine (GT). Because the SOFC is in developing stage, it is too expensive to obtain. This paper proposes a feasibility study by using a burner (Comb A) to simulate the high temperature exhaust gas of SOFC. The second burner (Comb B) is connected downstream of Comb A, and preheated hydrogen is injected to simulate the condition of sequential burner (SeqB). A turbocharger and a water injection system are also integrated in order to simulate the situation of a real SOFC/GT hybrid system. The water injection system is used to simulate the water mist addition at external reformer.     

1180℃烧结炉专用工装设计

燃气轮机零部件"火焰筒"陶瓷烘干以后需要在1180±10℃的烧结炉内进行烧结工序,火焰筒上除了两个直径35 mm的圆孔及底部的扇形孔内壁20 mm内没有陶瓷涂层外,其他位置均涂有W-200高温陶瓷涂层,没有涂层的区域为被保护区域,可以直接与工装接触,传统工装采用一个活动销、一个固定销结构,该结构可以有效固定"火焰筒",但是工件拆装不便,工装移动时工件发生摆动,难以保证不与陶瓷涂层接触。结合之前情况对工装结构和材料进行改进,通过软件三维仿真和高温试验,成功研制出一种新的工装,有效解决了不破坏陶瓷涂层,方便工件装卸,移动时稳定性好等问题。     

Combustion characteristics of mixture of anode off gas and LNG in reformer

Fuel processing system which converts hydrocarbon fuel into hydrogen rich gas (by stream reforming, partial oxidation, auto-thermal reforming) needs high temperature environment (600-1000 °C). Generally, anode off gas or mixture of anode off gas and LNG are used as input gas for a fuel reformer. In order to constitute efficient and low emission burner system for fuel reformer, it is necessary to elucidate the combustion and emission characteristics of fuel reformer burner. In this study, lean flat flame using the ceramic porous burner was analyzed numerically and experimentally. Burning velocity of anode off gas calculated by CHEMKIN simulation was 51.8 cm, which was faster than that of LNG having 40.63 cm/s at the stoichiometric ratio because of high composition of hydrogen in anode off gas. As composition of LNG in mixture of anode off gas + LNG is increased, the burning velocity decreases and in the other hand the adiabatic temperature increases. CO, NO_x were measured below 50 ppm in operating load range of the reformer. Blue flame pattern was found as stable flame region for design of fuel reformer and anode off gas flame was maintained in blue flame pattern at equivalence ratio 0.55-0.62 under 1-5 kW power range.