燃煤锅炉掺烧褐煤的经济性与环保特性分析

目前大部分电厂锅炉实际燃用煤种与设计煤种不符,针对某电厂600 MW实际锅炉选取神木、褐煤和优混等煤种按不同的掺混比例进行混煤燃烧试验研究,分别得到混煤燃烧整体经济性和环保性的相关运行参数。试验结果表明:神木煤中掺混33%左右的优混A时锅炉效率可达94.78%,表现为经济性最佳;掺混33%左右的褐煤时污染物排放总量相对较低,表现为环保特性最佳。     

用统计学的方法确定新（扩）建电厂的煤种

该文采用数理统计的方法为新（扩）建电厂选定煤种。为了准确获得将来电厂运行的煤种的特性参数，通过对各煤样的参数分析，可得到煤种各参数值的范围及落在此范围内的置信度。置信度的大小可以根据锅炉制造厂和设计院的设计要求预先给定。由此可控制锅炉本体的设计裕量，既能满足将来电厂运行煤种的变化，又能减少锅炉在设计时不必要的过大的裕量，降低投资。     

电厂锅炉混煤燃烧技术应用现状及分析

为降低发电成本,拓宽煤炭供应渠道,国内各燃煤发电厂相继开展了锅炉非设计煤种的掺烧试验研究。首先介绍了电厂锅炉混煤掺烧常见的三种方式,分析了这三种混煤掺烧方法的优缺点,然后介绍了国内电厂掺烧烟煤、褐煤、无烟煤的情况;分析了目前电厂锅炉掺烧烟煤、褐煤、无烟煤时所存在的问题,并提出了一些切实有效的技术措施;最后分析了混煤燃烧对锅炉运行的影响,指出需要对燃烧混煤时锅炉性能的变化、掺烧经济性等问题做深入研究。     

电厂锅炉燃用非设计煤种--神华煤的运行调整

根据电厂锅炉在燃用神华煤的过程中表现出的各种特性,就预防锅炉严重结渣、制粉系统爆破以及提高锅炉运行的安全性和经济性等问题进行了详细的分析,根据锅炉试烧神华煤的运行经验,得出了在运行上采取有效的措施,即富氧燃烧、合理吹灰和掺烧其他煤种等就能使炉内的结渣得到有效改善,为今后在非设计煤种锅炉上推广燃烧神华煤提供了宝贵的经验。     

670t/h锅炉结焦原因分析与燃烧器改造

煤粉锅炉燃烧时,结渣是锅炉一直存在的问题.锅炉设计煤种和燃烧方式存在着不适应,就容易导致炉膛结渣.锅炉燃烧煤种偏离设计煤种,而对燃烧的煤种特性分析不够深入,锅炉在燃烧时,由于燃烧器本身的调整不能适应煤种多变的情况,最终将导致炉膛结焦,甚至出现因结渣而引发锅炉停运.针对670 t/h锅炉因煤种和燃烧方式不相适应而导致炉膛结焦的原因进行分析,并对锅炉燃烧器进行重新布置,改善炉膛结焦.     

煤质结焦特性分析及防止结焦的措施

针对某电厂的分析煤种进行了灰分和结焦特性的分析，并在燃烧器布置方式、空气动力场的组织等方面采取了相应的措施，确保锅炉正常燃烧。     

680 MW超超临界锅炉混煤燃烧特性的热重试验及锅炉选型建议

采用热重分析仪对西塞山发电有限公司二期工程2×680 MW超超临界锅炉拟燃用混煤的着火稳定性和燃尽性进行了分析,结果表明:设计煤种的着火稳燃性一般,燃尽性较差.同时,根据锅炉混煤的燃烧特性提出了锅炉设备选型的初步建议和运行参数选择建议.综合混煤的燃烧特性和锅炉对煤种的适应性分析,得出锅炉采用切圆燃烧方式是较好的选择.     

煤粉浓度对火焰温度影响的试验研究

根据质量作用定律及燃烧基本理论,本文提出采用较高的煤粉锅炉入炉的煤粉浓度以使提高着火区火焰温度,从而使燃烧更加稳定,在单火嘴热态试验台上,用黄石电厂和汉川电厂的两个煤种,分别采用多个不同的煤粉浓度进行了燃烧试验。     

配风方式对某电厂锅炉燃烧及结渣特性的影响

为了节约燃煤成本,国内部分电厂开始采用较廉价煤种作为燃料,燃料的改变势必影响到锅炉换热效果,降低锅炉热效率,而通过调整燃烧方式可以降低这种不利的影响,本文通过数值模拟的方法分析了不同配风方式时炉膛内的燃烧和结渣特性的影响,综合考虑燃尽率、飞灰含碳量、含氧量、速度分布以及炉膛出口烟气温度等因素,对于某电厂锅炉的配风方式建议选用宝塔配风。     

660MW四角切圆锅炉混煤燃烧数值模拟分析

为了优化煤粉燃烧,提高电厂效益,以660MW超超临界四角切圆锅炉作为研究对象,利用CFD数值模拟方法对该锅炉混煤燃烧状态进行模拟分析。通过对多种掺混比例沿炉膛高度方向O2浓度、NOX浓度、CO2浓度等云图分布,对比分析了炉内燃烧状态。结果表明,在设计煤种与现有煤种掺混比例为4:1时,NOX浓度在炉膛中心明显增加,O2浓度在三种掺混方式下分布较为接近。在距一次风喷口较近区域,CO2的浓度相对较少;在壁面处,部分煤粉颗粒流动受阻,局部CO2变高。对比分析确定了该锅炉掺混的最佳比例,对合理选择煤种配比提供参考。     

Strategies for high-performance supercapacitors for HEV

Our paper highlights the role of supercapacitors in hybrid electric vehicles (HEVs), the current response to the worldwide demand for a clean and low fuel-consuming transport. The main strategies for increasing the specific energy of supercapacitors, which are electrochemical energy storage/conversion systems of high-specific power, are discussed, with the focus on electrode material, electrolyte and electrode/electrolyte interface properties. Particular emphasis is given to the use of ionic liquids (IL), which are attracting much attention as green and solvent-free electrolytes, and to the development of high-voltage, IL-based hybrid supercapacitor with high surface area carbon negative electrode and poly(3-methylthiophene) positive. Based on the results of laboratory cells featuring N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide and 1-ethyl-3-methyl-imidazolium bis(trifluoromethanesulfonylimide) ILs, the specific energies of hybrid supercapacitor modules are evaluated and compared to those expected for double-layer carbon supercapacitors displaying the same ILs.     

面向2050年的中国电力发展展望

电力转型是我国能源转型的重要环节。本文基于自主开发的适合我国中长期电力发展的源网荷储协调规划模型,将各类电源、骨干电网、需求侧资源与储能等统筹考虑,在计及相关发展目标与约束条件的情况下进行系统整体优化,求解了我国当前至2050年电力系统发展优化方案,可为研判我国电力系统发展路径、制定合理转型政策提供量化参考。     

Rules for paths construction for HENs debottlenecking

This paper is based on the heat exchanger network retrofit techniques, developed by Tjoe and Linnhoff and extended by Asante and Zhu. It considers, under the Network Pinch framework, two important cases — the Retrofit Initialisation and Topology Modification when the direct application of the classic Network Pinch concept and rules is not possible. With the help of a system of simple heuristics, these limitations are overcome which extends the application range of the Network Pinch framework.     

固定床反应器催化剂装填方案的优化

脱砷反应器压降升高会严重影响压缩机的安全运行,同时也制约了装置的加工量。分析认为,压降升高的主要原因是床层空隙率减小,而空隙率减小的主要原因是床层杂质增多,堵塞了颗粒间的空隙。阐述了级配剂和除垢篮在抑制压降升高方面的作用,提出级配剂加除垢篮的组合装填方案,有效解决了固定床反应器的压降问题,使撇头周期达到9个月,并对装填方案的进一步优化提出建议。     

Energy use for subsistence and prospects for development

This paper focuses on the present use of energy in the developing countries in order to estimate the energy required for subsistence-level activities and to see how much surplus is available for economically productive activities, taking into account both commercial and non-commercial (firewood, farmwaste) sources of energy. The energy required for subsistence is estimated to be in the range of 0.3 to 0.4 tce per capita. The consumption of most low income groups countries is below this level if only commercial energy is considered. Relations are derived to explain the uses of each of these energy forms in terms of economic and demographic variables from a sample of 82 countries. These relations are then employed to show that the dependence on non-commercial energy is likely to continue beyond 2000 AD and that, inspite of the annual rise of commercial energy consumption by 6%, the improvements in per capita consumption are small because of an increase in population and a decrease in per capita non-commercial energy.     

汽轮机低压叶片材料的选择

汽轮机低压叶片的材料选择对于保证整个汽轮发电机组的安全运行至关重要。从几个方面分析讨论了汽轮机低压叶片材料选择时需要注意的问题，并提出了解决办法。     

Probabilistic design factors for pipes used for hydrogen transport

Probabilistic design factors for pipes used for hydrogen transport are proposed for 3 locations: urban, peri-urban and rural areas.The used method involves a risk equation defined as the product of probability of leakage after failure, probability to have a gas flow greater than a prescribed value, probability of ignition, probability of lethal effects greater than a threshold value and probability of the presence of a person corrected by an environment factor and a risk reduction coefficient. The results obtained are less conservative than the deterministic values provided by ASME code.     

轧辊退火热处理炉自动控制系统

介绍了轧辊退火生产中自动控制系统的组成和各部分设备功能,通过此集散控制系统实现温度精确控制、数据记录监视以及仪表、电气设备的控制联锁。