循环流化床锅炉启动燃烧器简述及应用

本文结合一台220t/h循环流化床锅炉的点火启动实例介绍了启动及低负荷投油稳燃所用的风道燃烧器，床上启动燃烧器和床枪三种启动燃烧器的特点及其一些其它实际工程上的应用。     

天然气在渐变型多孔介质中的预混燃烧启动特性

针对天然气在渐变型多孔介质燃烧器中的点火启动过程进行了试验研究,通过监测燃烧器壁面或气体温度在点火后的变化,得到了影响启动时间的因素及特性,对特定的燃烧器而言,启动时间与预混气体当量比、流速以及点火位置有关,在冷态下点火,随着当量比接近理论当量比,启动时间减小;混合气体流速增大,启动时间增大;点火位置从燃烧器外移到燃烧器人口时,启动时间可大大缩小,采用小流速、近理论当量比条件下点火,对多孔介质层预热,有利于火焰迅速向上游移动,然后再调整到需求当量比或流速,可以大大减小燃烧器启动时间,采用孔径变化率高的渐变型多孔介质结构,也可以达到缩短启动时间的目的。     

循环流化床锅炉床下启动燃烧器的设计

本文介绍了循环流化床锅炉床下启动燃烧器的出力选取办法、结构布置形式和运行方式。启动燃烧器出力应根据锅炉点火时所需烟气温度以及所需的烟气量来确定；启动燃烧器由中心燃烧器以及外层冷却风道组成，中心燃烧器按平流式油燃烧器设计计算；点火风道的设计应考虑其空间能满足点火燃料的完全燃烧以及与冷却风的混合。     

循环流化床锅炉点火燃烧器的发展及应用

介绍了循环流化床的特点和循环流化床锅炉点火燃烧器的发展、类别.指出循环流化床锅炉点火或低负荷投油助燃所采用的床上启动燃烧器、风道燃烧器和床枪的特点及选择原则.     

LNASB轴向旋流式煤粉燃烧器的微油点火改造

微油点火是国家节能减排重点推荐的节能措施之一,各大型火电机组纷纷应用微油点火技术来减少启动过程的燃油消耗,但LNASB燃烧器由于有中心风的存在,使微油点火改造过程中燃烧器改动量非常大,必然影响着燃烧器正常性能。文章从扬二厂#4炉LNASB燃烧器微油点火系统改造讲述了该型燃烧器的改造可能性、改造调试过程、改造后燃烧器特性变化及节能效果。     

410 t/h循环流化床床下启动燃烧器制造工艺探讨

主要论述床下启动燃烧器制造中出现的疑难问题 ,在不影响生产周期且节约制造费用的前提下 ,采取相应措施进一步完善设计、工艺制造方案 ,使其性能、质量得以充分保证 ,对床下启动燃烧器的进一步开发具有一定的指导意义     

循环流化床床下点火技术探讨

文章主要依据UG 75/3.82 MCFB锅炉的风道燃烧器,从煤的燃烧机理出发,介绍了床下点火技术从冷态启动到投煤过程,在实际生产中的应用及点火启动过程中的注意事项。     

E-420-13.7-560KT锅炉低负荷燃烧器及小油枪点火技术改造

根据E-420-13.7-560KT锅炉低负荷燃烧器及小油枪点火技术改造情况,通过对运行情况的分析,认为对置翼型水平浓淡煤粉燃烧器及小油枪点火技术的改造有利于煤粉锅炉的启动、停止以及低负荷下的稳燃,可达到节油的目的,值得在同类型锅炉上推广.     

浓淡煤粉椭圆锥稳燃技术的研究与应用

在充分研究煤粉燃烧机理的基础上,剖析了国内外燃烧器及其燃烧技术,研制了和开发了浓淡煤粉椭圆锥燃烧器,实现了低负荷燃,启动少油火功能。     

灵武电厂等离子点火燃烧器原理及调试

介绍了DLZ-200型等离子点火燃烧器的工作原理和系统组成,以灵武电厂600 MW机组为例,重点阐述了该燃烧器在调试过程中出现的几个关键问题,并给出了处理办法.试运结果表明,该系统完全可以实现无油启动及稳燃,具有很高的经济效益和社会效益.     

Bituminous coal combustion in a full-scale start-up ignition burner: Influence of the excess air ratio

A start-up ignition burner has been proposed to reduce oil fuel consumption during the firing-up process and partial-load operation. To investigate the influence of different excess air ratios on bituminous coal combustion in the start-up ignition burner, full-scale reacting-flow experiments were performed for an experiment setup. The ignition burner was identical to that normally used in an 800 MWe utility boiler. Gas temperature distributions in the burner were obtained for excess air ratios of 0.56, 0.75, 0.98 and 1.14 (corresponding to primary air velocities of 17, 23, 30 and 35 m/s). Coal burnout and the release of C and H were observed at the exit of the burner nozzle. Gases such as O₂ and CO were measured at the center of the burner. A change in resistance was obtained within the burner.     

电厂锅炉油枪节油改造

国电丰城发电有限公司锅炉在安装等离子点灰系统后,锅炉启动方式改变,锅炉燃油系统作用发生变化且油枪出力增大。通过将锅炉燃油系统油枪的雾化由蒸汽改为压缩空气,更改孔径小的油枪喷头,锅炉启动用油大幅度减少,取得良好的经济效益。     

Fast starting fuel processor for automotive fuel cell systems

A fuel processor was constructed which incorporated two burners with direct steam generation by water injection into the burner exhaust. These burners with direct water vaporization enabled rapid fuel processor start-up for automotive fuel cell systems. The fuel processor consisted of a conventional chain of reactors: auto-thermal reformer (ATR), water gas shift (WGS) reactor and preferential oxidation (PrOx) reactor. The criticality of steam to the fuel reforming process was illustrated. By utilizing direct vaporization of water, and hydrogen for catalyst light-off, excellent start performance was obtained with a start time of 20 s to 30% power and 140 s to full power.     

Portable power production from methanol in an integrated thermoeletric/microreactor system

Catalytic self-ignition of methanol over platinum supported on anodized alumina in a microburner is demonstrated. The effects of air flow rate and air/methanol ratio on the system start-up time and steady state temperature have been studied. The air flow rate strongly affects the system start-up time. However, at the same flow rate, the start-up time is not affected by the air/methanol ratio over the range studied. Computational fluid dynamics simulations confirm these experimental findings. It is proposed that high flow rates and relatively lower fuel content can lead to attaining steady state faster with minimal fuel utilization. Transient axial temperature profiles showed that the hot spot of the reaction started at the inlet of the burner and did not shift downstream with time under most reaction conditions. The burner effective thermal conductivity was increased using copper thermal spreaders on the burner outer walls, allowing for thermally uniform walls. The uniform temperature profile allowed for optimal integration of the microburner with a thermoelectric device. The integrated microburner/thermoelectric device was shown to self-start from room temperature. The maximum power generated with the thermoelectric was 0.65 W and the maximum thermal efficiency was 1.1%.     

某型推进柴油机最低起动空气压力偏高故障原因分析

针对某型船用V型推进柴油机在冷态起动时，起动空气压力满足柴油机起动要求情况下无法起动的问题。通过系统排查，确定故障原因为高压油泵柱塞偶件工作配合间隙在公差的上限所致。在此基础上完善了该型高压油泵的加工和试验规范。     

Some considerations of start up in the design of fluidized bed boilers

An auxiliary start-up system is required in fluidized bed combustors in order to heat the bed to a temperature at which coal fed to the bed will ignite and burn without producing excessive smoke. Four methods are used by the U.K. National Coal Board, the one selected for a particular application being dependent on the type of solid fuel used and the type of appliance. To illustrate the nature of the design calculations associated with start-up, the paper describes the principles of a mathematical model developed to determine the rating of burner required for the hot gas start-up approach.     

Modeling of assisted cold start processes with anode catalytic hydrogen–oxygen reaction in proton exchange membrane fuel cell

Catalytic hydrogen–oxygen reaction is a potentially effective way to help start up proton exchange membrane fuel cells (PEMFCs) from sub-zero temperatures. In this study, the anode hydrogen–oxygen catalytic reaction is implemented in a three-dimensional multiphase cold start model. It is found that successful cold start from −20 °C can be achieved with the assist of the catalytic reaction in galvanostatic mode. With anode catalytic reaction, the start-up current density must be moderate, because a high current density lowers the assisted heating effect, and a low current density slows down the start-up process. The temperature difference between the anode and cathode catalyst layers (CLs) is negligible, which indicates that the heating location in the electrodes for the catalytic reaction makes no significant difference. The humidification of anode due to the catalytic reaction also reduces the ohmic resistance of the membrane, leading to enhanced performance during the start-up processes.     

Numerical analysis of start-up operation of a tubular solid oxide fuel cell

The purpose of the current study is to numerically predict the start up behavior of a tubular solid oxide fuel cell (SOFC) using a 2-D transient model. The developed model provides the transient response of the start-up mode as well as the steady state operation of the SOFC. A code based on finite volume method is utilized to solve the transient nonlinear transport equations of the cell (momentum, species and energy equations). To account for the Ohmic losses and Joule heating of the current that passes through the cell body, a discretized network circuit is adopted. The local electrochemical parameters are calculated based on the local pressure, temperature, and concentrations of the species. At each time step an iterative procedure is used to solve the electrochemical, electrical and transport equations simultaneously. The model predicts the cell output voltage, the local EMF and the state variables (pressure, temperature and species concentration) during the start up. It also predicts the cell heat-up rate for hot input gases as well as the start up time of the SOFC. The results show that the gases mass flow rate and temperature affect the heat-up rate. Also during the start-up, the cell electrical response is about 2.5 times quicker than the cell temperature response. The start-up time for the cell output voltage is about 50 min.     

超(超)临界锅炉启动系统安全性影响的定量分析

对各类型启动系统的安全性影响进行了定性对比分析,重点采集并定量计算分析了超(超)临界锅炉启动阶段的实际运行数据。定量分析结果表明采用带BCP的启动系统在安全方面有明显优势;而采用大气扩容器启动系统时,锅炉转干态前后水冷壁出口温度变化速率较大,且系统无法满足锅炉热态、极热态启动的需要。