高温空气燃烧技术的特点及其应用前景

高温空气燃烧技术（HTAC）是九十年代初在日本开发的一项新的燃烧技术,该项技术具有节约燃烧、低NOx排放、热利用率高和减设备尺寸等特点。分析了HTAC的火焰温度分布特征及其可降低NOx排放的原理。高炉煤气、焦炉煤气及94．5％高炉煤气与5．5％焦炉煤气的混合煤气应用于HTAC技术的理论计算结果表明,理论燃烧温度随着预热空气和燃气温度的升高而升高,因此HTAC技术可燃用传统燃烧方式不能使用的低热值燃气。此外,空气、燃气双预热可奖排烟温度将得更低,热利用率提高更高。最后,指出了在燃油、燃气锅炉及煤（或可燃固体废弃物）气化系统中采用HTAC技术的可能性。     

高效蓄热式工业炉

利用高效蓄热燃烧技术开发的高效蓄热式工业炉，将蓄热式热回收和换向式燃烧系统与炉体结合于一体，空气和煤气双预热到1100℃，系统排烟温度低于130℃，可在轧钢加热炉上直接燃烧全高炉煤气，工业炉热效率达到70%以上，提高加热质量减少钢坯氧化烧损。     

不同气体燃料燃烧特性及热特性分析

由于气体燃料容易实现燃烧过程精确控制及燃烧的清洁化,文章采用数值计算的方法,对6种常见气体燃料的燃烧特性及热特性进行理论计算,并通过改变空气过量系数、空气预热温度、富氧度等燃烧条件对其燃烧特性及热特性进行对比和分析.结果表明,预热温度每提高200℃,对于天然、焦炉煤气和沼气来说,可提高燃烧温度约90℃,高炉煤气和发生炉...     

燃高炉煤气富氧燃烧器的数值模拟

基于燃烧理论,以高炉煤气为燃料,通过燃烧计算,选定蜗壳式旋流配风器,设计一种适合高炉煤气等低热值煤气的燃烧器。用FLUENT软件进行燃烧过程的数值模拟计算。模拟结果表明,使用30%左右的富氧空气和煤气预热300℃时,燃烧温度提高,火焰中高温区面积增大,燃烧效果及经济效益最佳。     

高炉煤气燃烧数值模拟研究

研究高炉煤气燃烧特性对于钢铁企业节能减排、降本增效具有十分重要的现实意义。基于数值模拟方法研究高炉煤气的燃烧特性,探讨空气过量系数、预热温度和富氧率等因素对燃烧温度及NOx浓度分布的影响规律,为改进高炉煤气燃烧技术提供理论依据。研究表明:空气过量系数增加使反应后平衡温度降低,燃烧温度峰值、反应平衡温度随空气预热温度及富氧率的增加而升高,NOx排放随三个因素的增加而增加,综合考虑,纯高炉煤气燃烧空气过量系数应取1.1,空气预热温度选700 K,富氧率控制在25%。     

热风炉高风温技术改造

济钢炼铁厂4#高炉热风炉采用了合达式热风炉技术.该热风炉设有新型顶燃陶瓷燃烧器和高温旁通烟道.燃烧时,火焰温度高,气流分布均匀,综合排烟温度600℃左右,空气、煤气可预热到300℃,换热器后烟气温度低于180℃.以单一高炉煤气为燃料,不建任何辅助设施,热风温度可达1 250℃以上.     

高炉热风炉掺烧混合煤气实践

该公司炼铁厂高炉热风炉原用高炉煤气做燃料来加热 ,由于高炉煤气理论燃烧温度较低 ,导致热风温度上升空间有限 ,低热风温度已不适合现有生产节奏的要求。因此 ,为提高热风温度 ,改用掺烧混合煤气 ,取得了较好的效果     

某钢厂连续退火炉燃烧状态的诊断及优化

针对连续退火炉辐射管加热段热处理温度偏低,达不到退火工艺要求的问题,对辐射管加热段供热系统燃烧状态进行诊断.发现该段供热系统的空煤气配比不合理、部分烧嘴的煤气压力偏低,从而引起燃烧状态不佳,炉温偏低等现象.从燃烧状况优化的角度出发,对辐射管烧嘴燃烧过程、燃料介质配比等进行了研究,分析烧嘴前煤气压力偏低的问题,发现煤气结焦和管道积灰导致堵塞,再利用烟气成分分析等手段确定辐射管烧嘴的最佳燃烧效率点,使各支烧嘴的燃烧状况趋于一致,空煤气配比合理,提高燃烧效率和加热质量.然后进行拖偶试验对退火炉的热处理温度进行考核验证.结果 表明,通过燃烧状况诊断和调试,使辐射管加热段热处理温度提高了100℃以上,达到热处理工艺要求.     

钢铁厂低热值煤气合理利用的原理与技术

从能级系数、可燃界阴、烟气量等几个方面，分析了高炉煤气的低品位特性。通过能量平衡模型，论述了燃气－－蒸汽联合循环有实现能量梯级利用和提高热效率的优点。通过燃气互换性条件分析，论述了添加高热值燃气燃烧的合理性和效果。最后，介绍了预热空气、稳燃器等低值燃气的强化燃烧措施。     

新型蓄热式高炉煤气加热炉

论述了一种可将高炉煤气等低热值煤气用于工业高温加热炉的新方法。高效蓄热式热回收装置与炉体有机地结合为一体并辅以电子控制系统，可将助燃空气和煤气同时预热至１１００℃，出炉废气温度仅为１５０℃，可降低能耗５０％以上，产量提高３０％。     

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.     

外二次风旋流数对燃烧室内湍流燃烧与NOx生成的影响

建立了采用分级进风方式的旋流燃烧室实验装置。在此实验装置上分别对天然气进行了湍流旋流燃烧的实验研究。在保持过量空气系数不变的条件下,测量了在不同外二次风旋流数下,燃烧室内烟气的时均温度场,O2,CO2,CO和NO浓度场的分布。由实验结果分析讨论了二次风旋流数对旋流燃烧室内湍流燃烧及NOx生成的影响。     

Experimental study on combustion characteristics of compost using New‐type combustor

The aim of the present study is to develop the biomass furnace combustor, which can effectively use the compost as a fuel. Here, the compost that is made from pig's waste and has the calorific value of 2000 kcal/kg is employed here. Emphasis is placed on the optimum conditions of fuel and air flow rates and moisture content of the compost and the corresponding combustion gas components and combustion gas temperature in the combustor. It is found from the study that (i) except 40% of the compost's moisture content, the self‐combustion of compost as the fuel takes place, (ii) the combustion gas concentrations are affected by gas temperature, and (iii) the optimum value of the air‐to‐fuel ratio is obtained based on the gas temperature and the concentration of combustion gases. Copyright © 2016 John Wiley & Sons, Ltd.     

天然气柔和燃烧锅炉结构参数影响模拟研究

在天然气锅炉中引入柔和燃烧技术将大大降低NOx排放,高速未燃气卷吸高温烟气回流并与之快速掺混再燃烧是柔和燃烧的重要特征,因此,开展天然气锅炉关键结构参数优化设计以组织流场形成柔和燃烧所需的高温低氧反应气氛非常必要。基于天然气锅炉的工况特征,设计了热负荷15kW的模型燃烧室,采用数值模拟手段详细研究了燃烧室高度、喷嘴孔径、喷嘴相对位置及烟气出口尺寸对燃烧室流场、组分场及关键参数——烟气回流比的影响规律,并最终确定了燃烧室结构优选方案,对天然气锅炉柔和燃烧机设计提供理论基础数据。     

A review on plasma combustion of fuel in internal combustion engines

In recent years, new ways of improving the combustion efficiency of fuel during gas turbine operations have been developed. The most significant has been the application of plasma technology for the combustion of fuel in gas turbine operations. Plasma is formed when gas is exposed to either high temperature or high‐voltage electricity. This technology is very promising and has proven to enhance the performance of gas turbines and reduce toxic emissions. Recent studies have shown the use of different types of plasma applications in gas turbine operations such as plasma torch, filamentary discharge, and nanosecond pulse discharge, whose results show that plasma technology has great potential in improving flame stabilization, the fuel/air mixing ratio, and flash point values of these fuels. These findings and advances have further provided new opportunities in the development of efficient plasma discharges for practical uses in plasma combustion of fuel for gas turbine operations. This article is a comprehensive overview of the advances and blind spots in the knowledge of plasma combustion of fuel during internal combustion engine operations. This review also focuses on applications, methods, and experimental results in plasma combustion of fuel in gas turbines.     

Numerical investigation on hydrogen-enriched methane combustion in a domestic back-pressure boiler and non-premixed burner system from flame structure and pollutants aspect

In this paper, the non-premixed hydrogen-enriched methane-air combustion was investigated numerically with the use of a CFD code. In the first part of the study, the combustion experiments were performed in a back- pressure boiler using natural gas. The intake rate of fuel was kept constant as 45 Nm³/h while the coefficient for the air excess ratio was changed between 1.2 and 1.35. After the experiments, the numerical analyses were performed. The Fluent code was utilized as the simulation instrument. The eddy dissipation combustion model was selected to be used in the numerical analyses, since it is known that this combustion model can save computational time and fairly predict the combustion flame structure and emissions. Pure methane and natural gas were taken as fuels in the numerical analyses. The obtained results from the numerical analyses were validated with the experimental flue gas temperature and emission measurements. Then, the hydrogen-enrichment of pure methane fuel was investigated numerically in such a way that the boiler capacity (432 kW) was kept constant. The coefficient for the air excess ratio was 1.2 for all the considered combustion simulation cases. The hydrogen addition ratio was 25%, 50% and 75% by mass, respectively. The thermal NO emissions and temperature distributions in the combustion chamber were obtained according to the different hydrogen-enriched methane fuel combustion cases. In addition, the emissions contained in the flue gas together with the temperature values were calculated. The obtained results from the numerical studies indicate that the hydrogen-enrichment of methane reduces the carbon emissions, while it substantially augments the formation of the thermal NO emissions. The calculated thermal NO emission value in the flue gas is 147 ppm for the pure methane combustion case, and it is 566 ppm for the combustion case with 75% by mass of hydrogen addition ratio. Therefore, it is determined that hydrogen fuel is a pollutant from the thermal NO emission aspect for the considered enrichment ratios in the studied domestic boiler-burner system.     

高温空气燃烧技术的开发应用、技术优势及其展望

高温空气燃烧技术和高温空气气化技术是当前世界节能与环保领域中的两大新技术,二者均采用高于燃料着火点温度的高温空气作氧化剂或气化剂。介绍了利用蓄热式高温烟气余热回收装置和专门的高温空气发生器产生高温空气的方法,前者主要用于高温空气燃烧技术,后者主要用于高温空气气化技术。概括了高温空气燃烧技术和高温空气气化技术的应用状况,总结了其技术优势,并指出高温空气燃烧技术和高温空气气化技术符合中国国情,具有巨大的开发潜力和广阔的市场前景。     

Optimum conditions for a natural gas combined cycle power generation system based on available oxygen when using biomass as supplementary fuel

Due to the higher oxygen content and lower heating value, the amount of biomass required in a combined cycle, where it is used as supplementary fuel, to meet a given energy demand is such that the biomass consumes almost all of the oxygen remaining from gas turbine combustion process under certain conditions. This situation requires additional air for biomass combustion thus reducing the cycle efficiency and the net work output rate while increasing CO₂ emissions. Three conditions at which the oxygen is completely consumed are identified based on alterations in net fuel utilization. The first condition is linked to fuel utilization, which is observed to be significantly affected by variations in temperatures at three locations in the combined cycle (air temperature entering the gas turbine combustion chamber, gas turbine inlet temperature and HRSG inlet temperatures). The second condition relates to the characteristics of the feedstock (oxygen content of the biomass and heating value of natural gas). The heat loss due to combustion of natural gas and biomass is the third condition that affects oxygen availability. The current work assesses these conditions in order to identify the proper condition at which no additional air is required for supplementary firing of biomass.     

The effect of wood biomass blending with pulverized coal on combustion characteristics under oxy-fuel condition

In this study, combustion from the co-firing of coal and wood biomass, and thermal characteristics such as ignition temperature, burn-out temperature, and activation energy were discussed using a thermogravimetric analyzer (TGA). We investigated the effects of biomass blending with two kinds of pulverized coal (bituminous Shenhua, and sub-bituminous Adaro) under air and oxy-fuel conditions. The coal fraction in the blended samples was set to 1, 0.8, and 0.5. The oxygen fraction in the oxidant was set to 0.21, 0.3, 0.5, and 0.8. The ignition temperature was governed by the fuel composition, particularly in the blended biomass which has a much higher content of volatile matter comparing to coal. However, the burnout temperature, which shows a strong relationship with char combustion, depended on the oxidant ingredients rather than on the fuel components. Thermal characteristics such as ignition, burnout temperature, reaction region, and heat flow were very similar between air and a 0.3 oxygen concentration under oxy-fuel conditions with Shenhua coal.     

燃气轮机燃烧室柔和燃烧热力学与燃料条件的计算分析

本文通过零维数值模拟,对基于烟气循环的不同级别燃气轮机燃烧室中实现柔和燃烧的条件进行了计算分析。结果表明燃气轮机燃烧室柔和燃烧主要受回流烟气和燃料、空气的混合物温度的影响,烟气回流起到缩短混合物点火延迟时间的作用。由于不同燃料和不同负荷条件下混合物自燃温度变化不大,柔和燃烧具有较好的燃料适应性和变负荷性能。分析还表明未完全反应的烟气不会影响柔和燃烧工况范围。