300 MW CFB锅炉排渣系统的改造与升级

为了解决300 MW CFB锅炉运行中风水冷渣器结焦、堵渣及超温的问题,提高CFB锅炉机组的运行可靠性,以山西某电厂300 MW CFB锅炉排渣系统改造升级项目为例,分析了锅炉冷渣器超温结焦、排渣不畅等问题,最大限度发挥了CFB锅炉的优越性,提高机组的带负荷能力。     

350MW超临界直流锅炉结焦原因分析与改进

针对超临界直流锅炉水冷壁严重结焦、机组不能维持额定负荷连续运行的问题,通过优化燃烧控制策略,结焦问题得到有效缓解,机组能够满负荷连续稳定运行,机组运行安全性和经济性提高。     

四角对冲燃烧技术的探讨与应用

针对四角切向燃烧方式的锅炉运行中存在的烟温偏差、结焦等人们关心的问题 ,分析了几种四角燃烧方式的特点和缺陷以及成功事例 ,指出用四角对冲燃烧方式对老锅炉进行改造是解决烟温偏差、结焦等问题的好方法     

基于“MBEL”W火焰锅炉结焦现象原因分析及其对策

介绍了国电菏泽发电厂"MBEL"W火焰锅炉的设计特点,该锅炉在运行中遇到了因结焦而被迫停炉的重大问题,通过对锅炉运行情况的分析研究,找出了造成结焦的原因,并通过对设备改造和运行调整等措施消除了W火焰锅炉结焦问题,对同类"MBEL"W火焰锅炉在运行中出现结焦问题的解决具有指导性作用。     

600 MW燃用褐煤墙式切圆锅炉运行中存在的问题分析及优化措施

对某台采用四墙布置燃烧器切圆燃烧的600 MW超临界锅炉进行了优化调整试验和数值模拟,对锅炉存在的水冷壁严重结焦、超温爆管、炉膛出口速度及烟温偏差问题的原因进行了研究。结果表明：锅炉炉膛出口左、右侧存在速度与烟温偏差,燃尽风的投切对炉膛出口气流速度分布影响很大;提高一次风率对提高制粉系统出力有利,但过高的一次风率（40%以上）是导致锅炉发生水冷壁结焦和局部超温爆管的主要原因;一次风率控制在设计值36%左右,锅炉的运行状态明显改善。     

元宝山发电厂600MW机组锅炉降出力运行的原因分析

文章概述了我国第一台600MW机组锅炉被迫降出力运行情况;从设计和运行管理诸方面对结焦;再热器超温、制粉系统容量不足等锅炉降出力因素进行了全面剖析;并对提高机组运行水平问题提出了设备改进和运行管理方面的建设性意见.     

300MW流化床锅炉布风方式对床温偏差影响的模拟研究

米东热电厂1#流化床锅炉在运行过程中,中部床温与左右两侧床温偏差达到110℃以上,给运行人员优化调整带来困难。结合流化床锅炉的尺寸结构与运行特性,开展了风帽及水冷风室的数值模拟研究。结果表明,整个水冷风室的压力分布呈现中间高两边低的分布趋势,压力最高点和压力最低点的压强差值约为250Pa。因此,提出对布风板风帽进行通流改造,改善锅炉床温偏差问题,从而有效地缓解炉膛局部高温结焦问题,使该厂整体能耗下降。     

火力发电厂锅炉受热面管泄漏原因分析及处理研究

文中从某火力发电厂的实际案例出发,简略从设计问题、超温运行以及锅炉结焦三方面内容着手,阐述了火力发电厂锅炉受热面管泄漏的原因,并提出了几点应对措施,旨在为相关人员提供借鉴意义。     

35t/h煤粉锅炉燃烧器改进

针对山西焦化集团有限公司35t/h煤粉锅炉在实际运行中存在的过热蒸汽超温、炉膛结焦、飞灰含碳量等高问题，对现场进行了调查研究、原因分析、并利用锅炉大检修机会，对燃烧器作了相应技术改进，运行效果良好。     

循环流化床锅炉结焦问题分析

结焦是循环流化床锅炉运行中较为常见的故障,处理不好势必会严重影响锅炉的安全经济运行。根据循环流化床锅炉设计和实践经验,结合我公司自主开发和制造的循环流化床锅炉设计和运行情况,文章较为详细地分析了这种锅炉的结焦原因并就循环流化床锅炉设计和运行中如何预防结焦的问题进行了综合性的分析介绍。     

牵引车载荷对NOx排放和排温影响的试验研究

在五轴动力总成试验台架上对牵引车在不同载荷下进行同一路谱的排放试验,研究牵引车在不同载荷下NOx排放和排温的变化,得到载荷与排放物和选择性催化还原(selective catalytic reduction,SCR)上游排温的变化关系。结果表明:载荷为标定载荷的60%以下时,NOx比排放值与载荷基本呈线性相关;载荷超过标定载荷的75%时,NOx比排放值与载荷呈二次项相关;载荷在为标定载荷的23%以上时,NOx比排放值与SCR上游排温基本呈线性相关。利用该试验结论可以通过只进行单一载荷排放试验,判断车辆在其他载荷下的排放水平是否满足国家标准要求,并可通过载荷对排温的影响规律预判排放水平。     

建筑物冬季空气渗透耗热量分析

对冬季建筑物外围护门窗结构冷风渗透耗热量进行理论分析,考虑通过空气渗透和侵入造成的潜热热负荷,并对显热热负荷和潜热热负荷进行逐时计算,将结果进行比较分析。结果表明在冬季供暖空调标准工况下,24h周期内空气渗透造成的潜热热负荷约是其相应显热热负荷的8%。对于高层建筑以及室内温湿度要求较高的建筑,进行采暖负荷设计时有必要考虑这部分潜热负荷。     

基于分支限界法的火电机组负荷分配研究

针对大规模新能源并网调峰问题,提出不同调峰阶段火电机组负荷分配方法：分析火电机组调峰能力、调峰成本及二者之间的关系;以总煤耗成本、机组启停成本之和最小为目标,建立不同调峰阶段火电机组负荷分配优化模型;根据火电机组爬坡率、滑坡率,提出参与负荷分配机组的组合策略,并使用分支限界法对负荷分配优化模型求解。算例表明,随着火电机组调峰深度的增加,机组煤耗成本和启停成本减少,深度调峰运行下附加煤耗成本和机组损耗成本增加。     

Short‐term electric load forecasting using an artificial neural network: case of Northern Vietnam

Short‐term electric load forecasting is an important requirement for electric system operation. This paper employs a feed‐forward neural network with a back‐propagation algorithm for three types of short‐term electric load forecasting: daily peak (valley) load, hourly load and the total load. The forecast has been made for the northern areas of Vietnam using a large set of data on peak load, valley load, hourly load and temperature. The data were used to train and calibrate the artificial neural network, and the calibrated network was used for load forecasting. The results obtained from the model show that the application of neural network to short‐term electric load forecasting problem is very useful with quite accurate results. These results compare well with other similar studies. Copyright © 2004 John Wiley & Sons, Ltd.     

辅助弃风消纳的IVMD-LSTM电网典型时段负荷曲线拟合方法

准确地拟合负荷数据是表征负荷特性的关键环节。文章以电力网建设为背景,提出一种改进变分模态分解(Improved Variational Mode Decomposition,IVMD)和长短期记忆网络(Long Short-Term Memory,LSTM)结合的电网中长期典型时段负荷曲线拟合方法。该方法首先将曲率作为量化指标,减小常规VMD方法中K值的不确定性;其次,考虑高渗透率灵活负荷并网条件,精细化拟合特殊时段电网负荷,给出IVMD-LSTM的自适应电网负荷降噪及曲线拟合方法,提高负荷曲线拟合精度和效率;最后,通过实际算例证明了所提方法可有效减小电网典型时段负荷曲线拟合误差,辅助弃风消纳。     

电力系统短期负荷综合预测模型研究

在分析包括气象因素在内的多种因素影响的基础上，建立了考虑日特征负荷，日基本负荷，随机负荷及特殊事件负荷的电力系统短期负荷综合预测模型，并用华中电网一年实测负荷数据作仿真计算。结果表明，该方法与传统的预测方法相比精度更高，计算速度更快。     

Simulation‐based assessment of electric load management programs

The paper describes a methodology for assessing the contribution of storage type loads to an electric energy system's load curve and for evaluating the impact of load shedding actions, as part of load management programs, on the system's load curve. The methodology uses physically based individual load models and an aggregation procedure that accounts for both statistical reference patterns of the energy service demand and for the random nature of load use. A simulation case study of electric water heaters fed by a single transformer station is presented, to illustrate the effects of load control. The proposed methodology presents the possibility of evaluating—both at individual consumer level and at system level—the impacts of load management (LM) on the quality of service provided, besides anticipating the impact on the system's load curve. It allows an effective design of LM programs through variables such as the number of different load shedding schedules and their frequency of use by the utility. Copyright © 1999 John Wiley & Sons, Ltd.     

Plastic collapse of pipe bends under combined internal pressure and in-plane bending

Plastic collapse of pipe bends with attached straight pipes under combined internal pressure and in-plane closing moment is investigated by elastic–plastic finite element analysis. Three load histories are investigated, proportional loading, sequential pressure–moment loading and sequential moment–pressure loading. Three categories of ductile failure load are defined: limit load, plastic load (with associated criteria of collapse) and instability loads. The results show that theoretical limit analysis is not conservative for all the load combinations considered. The calculated plastic load is dependent on the plastic collapse criteria used. The plastic instability load gives an objective measure of failure and accounts for the effects of large deformations. The proportional and pressure–moment load cases exhibit significant geometric strengthening, whereas the moment–pressure load case exhibits significant geometric weakening.     

考虑需求侧无功不确定性的负荷聚合商运营优化模型

针对需求侧多种类负荷不确定性给负荷聚合商在运营过程所带来的挑战,建立考虑需求侧不确定性的负荷聚合商运营优化模型。首先,考虑需求侧用电特征,建立具有不确定性的负荷聚合模型;进而,考虑需求侧无功不确定性,以负荷聚合商收益最大化为目标,建立基于条件风险价值的负荷聚合商运营优化模型;最后;选取蒙东某配网地区的风光、负荷及实时电价数据,通过仿真对比验证所提出的运营优化模型可有充分利用需求侧响应为电网带来的调节能力,有效提高负荷聚合商的运营收益。     

Variability and uncertainty of wind power in the California electric power system

The California generation fleet manages the existing variability and uncertainty in the demand for electric power (load). When wind power is added, the dispatchable generators manage the variability and uncertainty of the net load (load minus wind power). The variability and uncertainty of the load and the net load are compared when 8790 MW of wind power are added to the California power system, a level expected when California achieves its 33% renewable portfolio standard, using a data set of 26,296 h of synchronous historic load and modeled historic wind power output. Variability was calculated as the rate of change in power generated by wind farms or consumed by the load from 1 h to the next (MW/h). Uncertainty was calculated as the 1 h ahead forecast error [MW] of the wind power or of the load. The data show that wind power adds no additional variability than is already present in the load variability. However, wind power adds additional uncertainty through increased forecast errors in the net load compared with the load. Forecast errors in the net load increase 18.7% for negative forecast errors (actual less than forecast) and 5.4% for positive forecast errors (actual greater than forecast). The increase in negative forecast errors occurs only during the afternoon hours when negative load forecasts and positive wind forecasts are strongly correlated. Managing the integration of wind power in the California power system should focus on reducing wind power forecast uncertainty for wind ramp ups during the afternoon hours. Copyright © 2013 John Wiley & Sons, Ltd.