CFB锅炉燃烧福建无烟煤低排污运行的工业型试验

在一台75t／h的工业循环流化床锅炉进行试验，测试过量空气系数、二次风率和煤种变化对燃用福建无烟煤的循环流化床锅炉运行中NOx、SO2、C0等污染物排放及飞灰燃烬度的影响，结果表明，在一定的过量空气范围内随过量空气系数的增大，NOx的排放浓度降低；CO的排放浓度降低；飞灰含碳量显著减少；SO2的排放浓度减少并趋于稳定，在一定范围内提高过量空气系数对于以福建无烟煤为燃料的CFB锅炉的炉内自脱硫燃烧有正面作用。当a不变时，氮氧化物的排放浓度随二次风率的增加而降低；可能存在有最佳二次风率，使得燃料氮的转化率最低。     

掺烧石油焦410t_h循环流化床锅炉NO_x排放特性研究

在掺烧石油焦的410 t/h循环流化床锅炉上就运行参数对NOx排放特性的影响进行了试验研究,阐述了燃用烟煤、70％烟煤 30％石油焦和50％无烟煤 50％石油焦等3种不同燃料时,NOx排放浓度随温度、过量空气系数、一次风率和钙硫比等参数变化而改变的规律.结果表明,燃用不同燃料,NOx排放浓度与其挥发分含量呈正相关关系;随温度的提高,NOx排放浓度增大;炉膛气氛对NOx排放浓度影响巨大,随过量空气系数和一次风率增大,NOx排放浓度增大;随钙硫摩尔比增大,NOx排放浓度减小.试验结果对掺烧石油焦的循环流化床锅炉运行具有参考作用.     

循环流化床中石油焦与煤混合燃烧SO2排放特性研究

在一座0．5MW1循环流化床热态试验装置上进行了石油焦与煤混合燃烧试验，研究了烟气中SO2的排放特性．对于石油焦与煤不同燃料配比，不同锅炉运行参数，如过量空气系数、床温、一次风率、Ca／S比等对烟气中SO2排放浓度的影响规律进行了研究．试验表明：对不同配比的燃料，随过量空气系数和一次风率的增大，SO2排放浓度降低；对于床温有一最佳温度，其SO2排放浓度最低；随Ca／S增大，SO2排放浓度降低。     

二次风改造和调整对燃用福建无烟煤循环流化床锅炉运行经济性的影响

先后对燃用福建无烟煤的DG75/3.82 11型循环流化床锅炉二次风机进行变频调速改造、量体定做高效节能型风机,并减小了二次风喷嘴截面面积,增强了二次风的穿透能力,改善了二次风的均匀混合效果,2台锅炉年平均飞灰含碳量下降了3.26个百分点。同时,二次风调整测试发现,在一次风量保持基本不变的条件下,随着二次风率的增加,飞灰含碳量开始明显减少;当二次风率在0.42左右时飞灰含碳量最低,然后飞灰含碳量随着二次风率的增加而增加。在过量空气系数λ不变的情况下,飞灰含碳量随着上、下二次风增加而减少,减少幅度逐渐收窄;当上、下二次风比超过1.3后,飞灰含碳量有所增加。在二次风率不变的情况下,灰渣比随着上、下二次风增加而减少,减少幅度逐渐收窄。     

CFB锅炉清洁燃烧福建无烟煤的研究综述

综述近年来关于CFB锅炉清洁燃烧福建无烟煤的研究，包括燃尽研究和低污染燃烧排放研究等。研究认为，致密的颗粒结构、很差的反应性、强烈的热破碎性等煤质及其燃烧特性是影响福建无烟煤在CFB锅炉中燃尽的主要因素；采用高炉膛、敷设卫燃带、采取中低循环倍率、提高分离效率的分离器等锅炉结构设计参数有利于福建无烟煤的燃尽；维持炉膛运行温度在1000℃左右、入炉煤采用窄筛分偏粗颗粒、适当提高二次风率等运行措施也有利于福建无烟煤在CFB锅炉中的燃尽。对于燃烧福建无烟煤的CFB锅炉而言。炉内脱硫是一种有效、便捷、低成本的脱硫工艺，但为达到较好的脱硫效果（〉50％），钙硫摩尔比需在2.5以上；当过量空气系数保持不变时，氮氧化物的排放浓度随着二次风率的增加而降低。对于燃烧福建元烟煤的CFB锅炉，存在有最佳二次风率，使得燃料氮的转化率最低。对CFB锅炉清洁燃烧福建无烟煤今后的研究提出了建议。     

循环流化床锅炉降低NO_x排放浓度试验与优化改造研究

NOx排放浓度低是循环流化床锅炉的主要优点之一,但国内一些循环流化床锅炉的NOx排放浓度不能满足《火电厂大气污染物排放标准》(GB 13223—2011)的要求,给电厂的环保、经济运行带来了不利影响。在研究分析了各种影响循环流化床锅炉NOx排放浓度的运行控制因素后,对循环流化床锅炉进行了降低NOx排放浓度的燃烧优化调整试验。结果显示:NOx排放浓度会随氧量、一次风率、床温的增加而增加,同时其还与上、下二次风比例、SO2排放浓度有关联。对于NOx排放浓度较高的循环流化床锅炉,可以采取二次风系统改造、增加烟气再循环措施,必要时增加SNCR脱硝系统。     

75t/h循环流化床锅炉运行优化试验

通过试验研究了过量空气系数、循环灰排放率、二次风率等参数对循环流化床锅炉效率的影响,为循环流化床锅炉的经济优化运行提供参考。     

降低燃用福建无烟煤CFB锅炉飞灰可燃物含量的措施

煤质特性、燃料颗粒、总体设计和运行工况是影响福建无烟煤在CFB锅炉中燃尽的主要因素。结合2台燃用福建无烟煤的××75／3．82—11型CFB锅炉的运行情况,采用窄筛分偏粗颗粒入炉煤、提高分离器的分离效率、改造回料风系统、增强二次风的扰动穿透能力、维持较高的燃烧温度、保持适当的过量空气系数和料层厚度、提高二次风率等措施,促进福建无烟煤在CFB锅炉中的燃尽,2台锅炉平均飞灰可燃物含量从2003年的22．17％降低到2009年第一季度的15．03％。     

油页岩干馏废水流化床焚烧过程中NO_x和SO_2的排放特性

在一座热输入功率为90 kW的鼓泡流化床焚烧试验装置上进行油页岩干馏废水焚烧试验,考察床温、过剩空气系数、一二次风比和Ca/S比对排烟中NOx和SO2浓度的影响.结果表明:由于废水中氨氮含量较高,焚烧时随着床温的升高,NOx的排放浓度呈现先下降后上升的趋势,而非广泛接受的单调上升的规律,SO2的排放浓度呈上升趋势;随着过量空气系数的升高,NOx的排放浓度呈先下降后上升的趋势,SO2的排放浓度呈下降趋势;随着二次风率的升高,NOx的排放浓度呈下降趋势,SO2的排放浓度呈上升趋势;随着Ca/S比的升高,NOx的排放浓度先上升后下降,SO2的排放浓度逐渐下降.本次试验各工况下NOx的排放浓度范围为104.2～257.9 mg/m3;SO2的排放浓度范围为36.7 ～179.8 mg/m3,均满足国家排放标准.     

粒度对循环流化床锅炉燃烧影响的试验研究

循环流化床燃烧技术具有高效,低污染,燃料适应性广的优点,燃用福建无烟煤的循环流化床锅炉在福建沿海地区得到了广泛开展,取得了许多的成果,但是普遍存在的问题是飞灰含炭量太高,热效率不高。在一台75 t.h-1的循环流化床锅炉上对三种不同粒度的福建无烟煤进行了燃烧试验,测量了炉膛各段的温度水平,获得了粒度对底渣、飞灰的粒径分布及其含炭量和热效率等的影响特性,并针对燃用福建无烟煤的循环流化床锅炉的优化燃烧提出了一些建议,对锅炉的运行具有一定的指导意义。     

新风量、送风方式和空调病症

本文叙述了新风量的大小和送风方式的不同与空调病症之间的关系。     

机车空压机不打风故障的分析处理

1　故障查找思路　　ＧＫ1Ｄ型液力传动内燃机车的空压机主电路示意图和空压机起动时的控制关系示意图如图 1和图 2所示。当出现空压机不打风的故障时 ,我们一般按这两幅控制关系示意图所示的线路 ,分析查找问题所在。其基本思路如下 :一是沿空压机起动控制线路查。查ＰＣ机、功放块、空压机起动接触器、保险。若都没问题 ,则查主电路。二是沿主电路查找 ,空压机的电机、电机接线盒内 (接线柱、接线片 )、电机绕组。2　故障的分析处理　　在实际检修过程中 ,具体可按如下步骤做 :( 1)看主电路中的空压机起动线路上的保险3ＲＤ、4ＲＤ是否烧…     

The effects of air leaks on solar air collector behaviour

The construction of conventinal solar air collectors and the fact that they will operate with a significant pressure difference between the heated air stream and ambient, suggests that significant quantities of air may leak into or out of them. A search of the literature reveals no consideration of the effects these air leaks may have on the validity of collector efficiency measurements, on the efficiency itself, or indeed what the meaning of efficiency is under such operating conditions. This paper discusses the meaning of collector efficiency when leaks into the collector occur, analyses the effects on efficiency measurements, and solves the collector efficiency for the simple case of a constant leakage rate along the collector. Assuming that air leaking in from ambient can replace deliberate fresh air supply to the load as in building heating, then significant measurement errors are made if air leaks in to the collector are not accounted for. Further, the collector efficiency is increased over the no leak case, so that complex construction methods to make the collector air tight are probably not warranted.     

Effect of air leak on long term performance of air heater

In this paper, the effect of an air leak on the air heater performance is investigated. “Air leaking in” and “air leaking out” systems are examined. The effect of various parameters like leakage rate, mass flow rate, solar insolation, plate length and ambient temperature has been studied. The possibility that air leakage can take place from any where along the length of the collector has been incorporated in the model. It is found that, for “air leaking in” systems, efficiency goes up, while for “air leaking out” systems, efficiency decreases from the no-leak situation, and it depends on the position of the leak.     

空气湿度对平板空气集热器效率的影响

对不同相对湿度下的湿空气密度、定压比热容、动力粘度和导热系数等热物性参数进行了计算。在给定的平板空气集热器模型下计算得出,工作介质为相对湿度50%的湿空气比工作介质为干空气的集热器效率高12.4%。文章研究分析了太阳辐射量、空气通道高度、入口空气流速及温度对平板空气集热器顶部损失系数和效率的影响,研究结果显示,它们对介质为干空气及介质为湿空气的集热器影响趋势一致。     

Analysis of exergy demand for air heating of an air handling unit

In modern buildings, an increasing amount of the consumed energy falls on ventilation systems. The amount of energy needed for ventilation depends on weather fluctuations, wind, interaction between natural gravity and air tightness of the building, heat exchangers used in ventilation systems, efficiency of other ventilation equipment, and operating mode of ventilation systems in the building. Ventilation systems are comprised of a variety of elements that facilitate processes using energy of different types. The main elements that use energy in ventilation systems are fans, heat exchangers, and heaters. They have a significant effect on both energy needs of a public building and the exergy efficiency of a system. In order to achieve a more efficient use of exergy in heat exchangers, it is recommended to execute processes under as little temperature difference as possible; however, this increases the area of heat exchangers. Results of the analysis show that it is recommended to design ventilation systems based on the temperature that corresponds with the maximum demand of exergy in order to use the heat recovery unit as much as possible in the system.     

空气调节二次回风系统的节能问题

讨论了二次回风系统在夏季工况下与一次回风系统相比的节能效果,以及在冬季工况如何更好降低能耗的问题,着重分析了冬季工况下机器露点对能耗的影响,并提出降低能耗的途径。     

地道风系统地埋管管径对出口空气温度的影响研究

构建了空气与地道壁面换热理论模型,用于计算地埋管出口空气温度,通过正交模拟分析了地埋管管径、长度以及进口风速对地埋管出口空气温度的影响,并与数值模拟结果进行对比。结果表明:地埋管管径极差值最大,可达20.4 m,是地埋管出口空气温度的主要影响因素,地埋管长度和进口风速为次要因素;随着管径的增大,出口空气温度随之升高;当管径为0.2 m时,出口空气温度降幅最大,管径大于0.6 m后,降幅逐渐减小,基本趋于稳定值,因此应控制管径在0.2~0.6 m。     

Thermoeconomic optimization of the geometry of an air conditioning precooling air reheater dehumidifier

Exergy method of optimization for the geometrical parameters of an air conditioning precooling air reheater with turbulent flow is developed in this paper. The method is based on exergy, economic analysis and optimization theory. As there are humid air streams involved in the heat transfer process, then there are irreversibilities or exergy destruction, which is due to pressure losses, temperature difference and specific humidity gradient. These principle components of total irreversibility are not independent and there is a trade‐off between them. Therefore, the purpose of this research paper is to study the effect of the geometry and the specific humidity of the two streams on the irreversibilities of a crossflow precooling air reheater dehumidifier. Also, the optimum balance between the three components of irreversibility is determined thereby giving the optimum solution for heat exchanger area. The total cost function is expressed on an annualized basis of the sum of the precooler capital cost and the running cost attributable to the precooler irreversibility. This total cost function is optimized in this paper according to the optimum heat transfer area and the total irreversibilities. Two optimum heat transfer areas were found for minimum total irreversibility and minimum total annual cost for a specific example. Finally, the relations between the typical operational variables such as heat transfer area, Reynolds numbers and the total annual cost for the precooler is developed and presented in graphs, which allow the calculation of the optimal heat transfer area, which gives the optimum irreversibility and minimum total annual cost. Copyright © 2005 John Wiley & Sons, Ltd.