600MW锅炉一次风机风量裕量探讨

该文以某600MW火电厂锅炉一次风机的实际选型计算为例，通过分析空气预热器不同漏风率对一次风机计算风量的影响，提出了一次风机的基本风量和风量裕量的确定方法，可为今后一次风机选型优化提供参考。     

某电厂480t CFB锅炉一次风量对飞灰含碳量的影响

本文针对某135MW循环流化床锅炉含碳量偏高的问题,通过燃烧调整实验,分析不同运行条件下的飞灰特性。结果表明,飞灰含碳量随粒径呈峰值特征,其中19～67μm含碳量明显较高,属于较难燃尽的碳,是q4损失主要来源。在分析运行条件对飞灰含碳量影响的基础上,提出降低19～67μm段飞灰含碳量是降低循环流化床锅炉飞灰含碳量的主要途径。     

350 MW机组锅炉两侧二次风量不平衡的原因分析及对策

对华能南通电厂1号炉锅炉两侧二次风量不平衡的原因进行了分析与查找,并采取了相应地措施,降低了炉膛出口两侧烟气温度的偏差,降低了飞灰可燃物,锅炉运行状况得到改善.     

135MW超高压循环流化床锅炉启动运行时的风量分配及标定

本文对135MW超高压循环流化床锅炉启动运行时的风量分配及标定进行了较为详尽的阐述,重点介绍了锅炉冷态风量标定的试验过程和分析结果。     

液力偶合器在电厂锅炉引风机风量调节中的应用

通过在锅炉引风机上实际应用液力偶合器进行风机风量调节方式改造后的运行效果及改前改后的数据比较分析,指出利用液偶进行变速调节后的引风机节能效果及优势。     

超超临界660 MW机组二次风量异常下降分析与研究

华能长兴电厂2号机组在270～280 M W负荷运行时发生多次A侧二次风量突降情况,严重时甚至突降至0,锅炉总风量同步下降,对机组的安全稳定运行产生严重影响.对2号炉A侧二次风量突降的具体原因进行了分析.通过查阅历史数据并听取西安热工院的分析意见后,提出了解决二次风量突降问题的措施.     

循环流化床锅炉冷态临界流化风量与运行风量的关系分析

利用厄贡准则式和浙江大学提出的计算式计算了宽筛分颗粒的临界流化风速以及冷热态临界流化风速的比值,分析了冷态临界流化风量与热态运行时风量的关系,认为两者基本相当时才能保证热态运行时床料良好流化。     

二次风量非均匀配比控制烟气偏差的理论分析及模型试验

针对切向燃烧锅炉普遍存在的烟气偏差问题,从工程应用角度出发,提出新的调节方式。通过调整上二次风量的分配,形成炉内烟气流动中局部的高压富燃区,挤压火焰主流,改变炉膛出口烟气流量分布,控制烟气偏差。从理论上分析其可行性,并通过冷态模化试验等研究手段进行检验。研究结果表明,这种调节手段可以平衡水平烟道两侧流量,达到削弱残余旋转,减小烟气偏差的目的。     

600MW燃煤锅炉二次汽欠温改造及实施效果

某电厂1号锅炉自投运以来,一直存在非满负荷下二次汽温达不到设计温度即二次汽欠温的问题,对锅炉运行的安全性和经济性带来了不利影响,急需对此进行改造治理。从长期运行数据及热平衡分析看,锅炉的原受热面布置不合理,需要进行改造。在详细热力校核计算的基础上提出了前分隔屏截短1、2和3 m的3种改造方案。通过热力计算结果的全面对比分析,选择对锅炉高温屏式受热面进行截短2 m的改造。改造完成后,锅炉运行稳定,非满负荷下二次汽温欠温问题得到了解决,取得了满意的改造效果。     

燃煤电厂锅炉最低稳燃负荷估算方法

目的  项目实施前需要预评价燃煤电厂灵活性运行的性能,其中包括锅炉最低稳燃负荷技术指标的预测。原有的经验和算法不能满足电厂灵活性评价需求,需结合目前设备能达到的性能指标,拟定新的锅炉最低稳燃负荷的半经验计算曲线。 方法  结合文献资料与工程经验,选取与稳燃指标关联性强的参数,采用统计和回归的方法,拟合出半经验计算曲线。 结果  以煤的挥发分V_daf、燃烧器总出力裕量系数φ作为自变量,并结合最小点火能量的统计分析值,可得到锅炉最低稳燃负荷的理论指标。 结论  新的计算曲线以工程资料可获得的已知参数作为输入,可相对精确地测算出不同条件下锅炉最低稳燃负荷的理论值,与实际运行试验数据吻合,可作为工程设计的工具。     

钝体高度变化对煤粉工业锅炉燃烧器流场特性影响的冷态实验研究

针对某新型适用于燃煤粉工业锅炉的燃烧器,冷态实验研究了其一次风出口处加装的钝体高度改变对燃烧器流场特性的影响。研究结果表明:钝体高度越高并不能使得回流效果越好,适当高度的钝体可以起到增加气流回流的效果。     

NOx control in large-scale power plant boilers through superfine pulverized coal technology

Superfine pulverized coal technology can effectively reduce NO _x emission in coal-fired power plant boilers. It can also economize the cost of the power plant and improve the use of the ash in the flue gas. Superfine pulverized coal technology, which will be widely used in China, includes common superfine pulverized coal technology and superfine pulverized coal reburning technology. The use of superfine pulverized coal instead of common coal in large-scale power plants will not only reduce more than 30% of NO _x emission but also improve the thermal efficiency of the boiler. __________ Translated from Journal of Shanghai University of Electric Power, 2006, 22(4): 333–337 [译自: 上海电力学院学报]     

机车牵引电机冷却风道空气流场的分析

利用ANSYS FLOTRAN对机车牵引电机冷却风道内流场进行三维计算分析,获得了管道进出口压差和流量,为新型机车冷却管道的设计提供了可靠的依据。建议改进风道进出口形状,避免或减少流动分离,提高设备冷效率。     

Some studies on the flow passage dimension for solar air heating collectors

The effect of the dimensions of rectangular ducts through which air flows in solar air heaters on the air heater performance has been studied for laminar, transitional and turbulent flows. The collector performance and required pumping power to maintain the flow are assessed from a simple mathematical model. The effective energy collected has been determined for different case studies, and the duct depth has been optimised with respect to this effective energy. That is, an optimum duct depth is determined for different flow rates for collecting maximum energy at minimum pumping cost.     

Influence of mass air flow ratio on gas-particle flow characteristics of a swirl burner in a 29 MW pulverized coal boiler

In a gas/particle two-phase test facility, a three-component particle-dynamics anemometer was used to measure the characteristics of gas/particle two-phase flows in a 29 megawatt (MW) pulverized coal industrial boiler equipped with a new type of swirling pulverized coal burner. The distributions of three-dimensional gas/particle velocity, particle volume flux, and particle size distribution were measured under different working conditions. The mean axial velocity and the particle volume flux in the central region of the burner outlet were found to be negative. This indicated that a central recirculation zone was formed in the center of the burner. In the central recirculation zone, the absolute value of the mean axial velocity and the particle volume flux increased when the external secondary air volume increased. The size of the central reflux zone remained stable when the air volume ratio changed. Along the direction of the jet, the peak value formed by the tertiary air gradually moved toward the center of the burner. This tertiary air was mixed with the peak value formed by the air in the adiabatic combustion chamber after the cross-section of x/d = 0.7. Large particles were concentrated near the wall area, and the particle size in the recirculation zone was small.     

固体表面液滴在吹风作用下的振荡特性

利用可视化实验观察了水平表面液滴在吹风条件下的振荡现象。针对水液滴在不同型号砂纸打磨的铜表面进行实验,观察到液滴在吹风条件下发生上下和左右两种振荡模式,在一定的条件下两种模式可以相互转化。通过细致的观察分析,总结归纳了振荡及转化发生的规律。实验结果表明：液滴的振荡特性同表面租糙度、液滴尺寸、风速等有一定的关系。振荡周期随着液滴尺寸增大而增大,随着风速的增大阶跃式增大;随粗糙度增大,液滴振荡周期有先增大再减小的趋势。     

Oscillation characteristics of droplets on solid surfaces with air flow

Visual experiments were conducted to observe droplet oscillation on horizontal surfaces with air flow. The different Cu test surfaces were polished with different grit sandpapers. Two liquid drop oscillation modes, forward‐backward and upward‐downward, were visually observed in the experiments. Additionally these two modes were observed to transition from one to another under some conditions. The results indicate that the oscillating characteristics were closely dependent on surface roundness, droplet size, and air flow velocity. A larger radius and higher air speed would decrease the oscillation frequency, while the frequency would initially decrease and then increase as the roughness changed from the smooth to rough plates. © 2005 Wiley Periodicals, Inc. Heat Trans Asian Res, 35(1): 13–19, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20098     

垃圾焚烧炉炉排风量测量方法的比较研究

自动燃烧控制(ACC)系统是垃圾焚烧自动控制的核心技术。基于ACC系统原理,并结合垃圾焚烧炉在不同场景下的风量测量特点,分析了均速管流量计、双文丘里流量计、热式质量流量计等主流流量计的测量原理和优缺点,为垃圾焚烧发电厂流量计选型提供依据。     

发电机空冷器传热与阻力特性研究

随着空冷汽轮发电机容量的增大,发电机内各部件的发热量也随之增加,空冷技术的重要性日益突出。但我国的空冷技术与国外相比还有一定差距,因此,利用循环风洞对几个特定结构参数的翅片式空冷器进行了模化试验研究,获得了空气侧传热与阻力特性的准则关系式,就试件结构参数对传热及阻力特性的影响机理做了详细的分析。试验结果不但为国产空冷器的性能与结构优化提供了计算方法,而且为空冷器制造企业实现自主研发提供了可靠的依据。