Influence of flue gas cleaning system on characteristics of PM_(2.5)emission from coal-fired power plants

This study investigated the influence of precipitators and wet flue gas desulfurization equipment on characteristics of PM_(2.5)emission from coal-fired power stations.We measured size distribution and removal efficiencies,including hybrid electrostatic precipitator/bag filters(ESP/BAGs)which have rarely been studied.A bimodal distribution of particle concentrations was observed at the inlet of each precipitator.After the precipitators,particle concentrations were significantly reduced.Although a bimodal distribution was still observed,all peak positions shifted to the smaller end.The removal efficiencies of hybrid ESP/BAGs reached 99%for PM_(2.5),which is considerably higher than those for other types of precipitators.In particular,the influence of hybrid ESP/BAG operating conditions on the performance of dust removal was explored.The efficiency of hybrid ESP/BAGs decreased by 1.9%when the first electrostatic field was shut down.The concentrations and distributions of particulate matter were also measured in three coal-fired power plants before and after desulfurization devices.The results showed diverse removal efficiencies for different desulfurization towers.The reason for the difference requires further research.We estimated the influence of removal technology for particulate matter on total emissions in China.Substituting ESPs with hybrid ESP/BAGs could reduce the total emissions to 104.3 thousand tons,with 47.48 thousand tons of PM_(2.5).

Recent Progress on Thermal Energy Storage for Coal-Fired Power Plant

With countries proposing the goal of carbon neutrality,the clean transformation of energy structure has become a hot and trendy issue internationally.Renewable energy generation will account for the main proportion,but it also leads to the problem of unstable electricity supply.At present,large-scale energy storage technology is not yet mature.Improving the flexibility of coal-fired power plants to suppress the instability of renewable energy generation is a feasible path.Thermal energy storage is a feasible technology to improve the flexibility of coal-fired power plants.This article provides a review of the research on the flexibility transformation of coal-fired power plants based on heat storage technology,mainly including medium to low-temperature heat storage based on hot water tanks and high-temperature heat storage based on molten salt.The current technical difficulties are summarized,and future development prospects are presented.The combination of the thermal energy storage system and coal-fired power generation system is the foundation,and the control of the inclined temperature layer and the selection and development of molten salt are key issues.The authors hope that the research in this article can provide a reference for the flexibility transformation research of coal-fired power plants,and promote the application of heat storage foundation in specific coal-fired power plant transformation projects.

Computational Study on Furnace Process in a Multi-burner Boiler of Pulverized Coal Fired Tangentially at Four Corners

Aiming at the optimization of the operation condition, a general numerical method for calculating pulverized coal combustion in a full scale furnace fired tangentially at four corners is adopted. “ k ε ” turbulence model is used for the gas phases and a stochastic approach based on the Lagrangian technique is used for particle phases. Two competing reactions model for the coal devolatilization and PDF (the probability density function) method for the combustion of the gas phases are employed. In the numerical simulations, assuming the air distribution of second port level is of pagoda, waist drum and uniform type. The results show that pagoda type air distribution is advantageous to ignition and smooth combustion of pulverized coal, and suitable to inferior coal combustion in practice. In the present furnace, the igniting distance at 1st and 3rd corner is longer than that at 2nd and 4th corner. The results from numerical calculations are in good agreement with those of observed in practice.

计算机视觉的电站锅炉水冷壁缺陷检测方法

发电厂锅炉巡检可有效避免安全事故发生,针对现场巡检过程中,锅炉水冷壁巡检区域较大,部分区域检测困难问题,开发一种基于YOLOv3模型的水冷壁缺陷检测系统。无人机携带视觉采集装置,对豫能集团某电厂锅炉水冷壁进行图像采集,画面经压缩后实时无线传输到检测末端装置,采用YOLOv3算法对水冷壁数据进行分析,对模型重要参数进行调整并做出样本增广与平衡化改进处理,提高检测效果,共测出磨损、裂缝、氧化等106处失效部位,与人工检测对比,成功率达77.9%。该方法解决了在巡检区域大、部分区域检测困难问题,使大型电站锅炉在开展水冷壁检测方面实际付出的成本得到有效缩减。

水性醇酸树脂涂料在严寒地区电站锅炉的应用

介绍了水性醇酸树脂涂料的发展历程及水性醇酸树脂的主要分类及特点。根据锅炉产品的特点及防锈要求,论证了水性醇酸树脂在锅炉产品应用的可行性及应用范围,并提出水性漆在严寒地区的施工工艺特点及注意事项。

对冲燃烧锅炉掺烧污泥炉内燃烧及碱金属分布模拟研究

以某660 MW对冲燃煤锅炉为对象,采用数值模拟方法研究了掺烧干化污泥时炉内燃烧及碱金属分布情况,分析了掺烧位置、过量空气系数和污泥Cl含量对炉内燃烧及碱金属组分分布的影响。结果表明:掺烧污泥后,侧墙壁面区域碱金属质量浓度较高,采用中上层燃烧器层掺烧污泥可降低碱金属的排放速率和燃尽风燃烧器附近区域金属壁温;提高过量空气系数不仅可提高煤粉燃尽率,还可以降低侧墙贴壁区域碱金属质量浓度;降低污泥中Cl含量可有效降低烟气中的碱金属质量浓度和其他碱金属向NaCl的转化率。实际锅炉掺烧干化污泥时,建议采用中上层燃烧器掺烧,并适当降低过量空气系数以降低掺烧对炉内受热面的沾污、结渣和碱金属型高温腐蚀风险。

电站锅炉受热面高温氯腐蚀特性及防控

随着我国双碳战略目标提出,电站锅炉向高参数方向发展。为研究新疆典型高氯煤在高参数锅炉焚烧过程中可能存在的腐蚀问题,探索防护措施,模拟了高参数下燃用高氯煤的锅炉气氛,对比了Super 304、T92、C-HRA-5、TP347H和12Cr1MoV的抗氯腐蚀能力并研究腐蚀温度(600、650和700℃)对氯腐蚀特性的影响。同时探究不同氧化钇质量分数(0%、0.2%、0.4%、0.6%和0.8%)的In⁃conel 625涂层的抗氯腐蚀能力。结果表明:腐蚀温度对材料的抗氯腐蚀能力影响很大,当温度高于700℃时,Super 304、T92、C-HRA-5、TP347H和12Cr1MoV均无法满足实际投产使用。在650℃时,C-HRA-5和TP347H表现良好,其拟合的腐蚀增重曲线分别为:y^(2)=312.371x,R^(2)=0.96和y=1.927x,R^(2)=0.94。Inconel 625涂层明显提高了12Cr1MoV基体抗氯腐蚀能力。随着涂层中氧化钇含量增加,抗氯腐蚀效果呈先升高后降低趋势,添加0.4%氧化钇效果最好。

基于粉管动压和煤粉分配的热态条件下中速磨煤机入口风量标定试验方法

针对中速磨煤机输运介质特点及入口管路、空间等限制,冷态纯空气条件下的测试方法无法保证磨煤机入口风量标定测试及时性的问题,热态运行工况下,选取流场稳定的磨煤机出口管道,采用等截面网格法测试各粉管动压和煤粉分配特性,并用循环迭代法获取风粉混合物流速,最终以实测的磨煤机出口风粉混合物流量与煤量、设计密封风量的差值对磨煤机入口风量进行标定。试验结果表明,在相同的实测原始数据基础上,采用上述方法获取的磨煤机入口流量更接近真实值,准确性较采用冷态纯空气条件下的计算结果提升约15百分点。该方法测试简单,实操性强,可有效提升中速磨煤机入口风量标定结果的准确性和及时性,同时,对相似工业环境中含粉气流流量的测试也有一定的指导作用。

电站锅炉承压部件剩余寿命评估方法专利申请概况

【目的】更好地掌握电站锅炉承压部件剩余寿命评估方法领域的发展现状。【方法】对国内外电站锅炉承压部件剩余寿命评估方法领域的专利文献进行搜集、标引和梳理,分析该领域国内外专利申请情况、重要专利申请人、地域分布和法律状态。【结果】电站锅炉承压部件剩余寿命评估方法的相关技术在日本已较为成熟,专利申请量趋于平稳;我国在该领域的研究虽然起步较晚,但近几年研发活跃度较高,已经成为相关技术的专利申请大国。【结论】电站锅炉承压部件剩余寿命评估方法的产业化应用还有待进一步加强,如何将这些技术投入实际工业生产获得产业化收益,是未来需要解决的问题。

Research and Development of Supercritical Carbon Dioxide Coal-Fired Power Systems

Using supercritical carbon dioxide(S-CO2)Brayton cycle instead of the traditional steam Rankine cycle is a promising technique to enhance the coal-fired power generation efficiency.Researchers from all over the world are actively designing and exploring efficient S-CO2 coal-fired power plants in recent years with great efforts made to overcome the significant technical challenges in the cycle layouts of S-CO2 and its specific thermal integration with coal-fired heat resources.This paper provides a detailed review of the research progress on the coal-fired power generation using S-CO2 Brayton cycles.The basic knowledge of S-CO2 properties,the promising S-CO2 power cycles and the conceptual designs for S-CO2 coal-fired power plants are comprehensively summarized,with some key issues in the constructing process and the corresponding engineering solutions being emphatically discussed.Based on the current achievements,the overall technical and economic evaluations on the S-CO2 coal-fired power system are figured out.Furthermore,the specific integration applications of S-CO2 cycles with different coal firing devices and modes including pulverized coal combustion,circulating fluidized bed combustion,oxy-coal combustion,pressurized fluidized bed combustion,chemical looping combustion are discussed.Finally,the main challenges requiring further studies are highlighted.

四角切圆锅炉不同燃烧器布置角度结渣特性数值模拟研究

为研究燃烧器布置角度对大规模掺烧低灰熔点烟煤锅炉的燃烧特性和结渣倾向,采用CFD方法对一300 MW四角切圆燃煤锅炉进行研究。结果表明,当燃烧器布置角度为38°时,温度分布均匀,火焰充满度高,燃烧稳定,但炉膛壁面易出现结渣;当燃烧器布置角度为42°时,高温火焰集中在炉膛中心,壁面温度降低,结渣倾向较小,但煤粉难以充分燃烧。综合考虑,当燃烧器布置角度为40°时,具有良好的燃烧效果,且结渣风险较低,可实现锅炉稳定运行。

大型电站锅炉掺烧污泥发电技术研究进展

污水处理能力量的提升,使得污泥产量增加。污泥富含病原微生物及有毒物质,对人类健康构成极大威胁,安全无害化和资源化处置迫在眉睫。燃煤电厂大型锅炉污泥掺烧是实现最大体积污泥处置方法之一。目前发达国家污泥掺烧工艺较成熟,使用较广泛,而我国在此方面起步较晚,污泥掺烧技术虽有一定进展,但仍存在诸多问题。本文综述了我国污泥掺烧背景,掺烧技术工艺路线和掺烧对燃煤锅炉的影响及未来研究方向。

火力发电厂锅炉水冷壁壁温预测耦合模型研究

锅炉水冷壁壁温不均匀分布会导致部分烟气温度过高,使得烟气中的热能无法充分传递给水冷壁,从而降低了换热效率,且壁温不均匀会使局部过热,引起燃烧不稳定,影响燃烧效果。为此,研究火力发电厂锅炉水冷壁壁温预测耦合模型。分析锅炉水冷壁壁温计算原理,计算锅炉水冷壁壁温,以此联合LSTM构建壁温预测耦合模型,确定构建模型结构与锅炉水冷壁壁温预测表达式。采用多点温度数据融合方式提升历史壁温数据与壁温预测结果的精准度,基于分批估计算术平均方法融合水冷壁多点温度数据,计算壁温的平均值与标准差。将水冷壁多点温度数据融合结果输入壁温预测耦合模型中,计算壁温预测误差补偿,获取最终的壁温预测结果,实现锅炉水冷壁壁温预测。实验结果表明:应用本文模型获得的水冷壁壁温预测结果与实际壁温保持一致,壁温预测平均误差仅为1.291%,表明本文模型水冷壁壁温预测效果好,具有较高的预测精度。

煤炭热值对机组运行和电煤消费影响及其应对措施

煤质是影响电厂运行过程中节能环保水平以及电煤消费量的关键因素,从煤炭的发热量、灰分、水分、含硫含氮量等参数的变化分析了煤质对机组运行及电煤消费量的影响机理。结合江苏省主要燃煤发电企业近两年入炉煤热值、发电量及发电耗煤数据,定量分析了电煤热值变化对全省电煤消费量的影响,按照2022年全省煤电发电量测算,全省电煤年平均热值每提高418.4 kJ/kg,全年电煤消费总量减少约3.9×10^(6) t,减少CO_(2)排放约1.0×10^(7) t。因此,从强化源头管控、合理储配掺烧、实施更新改造、精细运行管理和优化存煤结构等方面,提出控制电煤热值的相关措施,降低机组发电煤耗,控制污染物排放,起到节能减排的作用。

电站锅炉空气预热器风量分切防堵塞的改造设计

针对电站锅炉空气预热器风量分切堵塞问题,提出一种改造设计方案。该方案安装热风插板门和调节挡板,新增冷端热风喷口、直通管道、热控设备和电气设备,并纳入分散控制系统,有效解决了空气预热器风量分切堵塞问题。同时,采用热风清洗防堵系统,较好地适应回转式空预器冷端温度周向分布存在低温区域的特征。通过这些改造设计,电站锅炉空气预热器的性能和运行效率显著提高,能源消耗和运行成本大大降低,设备的使用寿命大大延长。

硬度测试在电站锅炉检验中的应用

硬度测试是一种非破坏性的测试手段,操作简单、速度快、适用范围广,广泛应用于锅炉检验。作为能量转换的核心设备,电站锅炉的安全可靠与否直接影响整个电厂的生产效率与安全。锅炉长期运行在高温高压的环境下,且受到多种腐蚀性介质的共同作用。因此,锅炉材料性能会发生较大变化,需定期对其进行硬度测试,及时发现材料的潜在退化问题,防止重大事故的发生。文章将重点研究如何在电站锅炉检验中应用硬度检测技术。

电站锅炉燃用高碱煤的高温腐蚀机理研究及预防措施

针对某电站锅炉掺烧新疆高碱煤后水冷壁减薄速率过快导致爆管泄漏问题,通过对炉内水冷壁整体外观检查、金相分析及入炉煤质化验结果,确定为典型的硫酸盐型高温腐蚀。根据分析结果从入厂煤管理、配煤掺烧、运行优化及检修管理方面提出相应的调整和预防控制措施。通过1个检修季的对比分析结果,腐蚀速率已得到有效控制。

基于FTA的电站锅炉事故应急预案完备性评估研究

为提升事故应急预案的质量,保障人民生命财产安全,运用事故树分析法(FTA)对应急预案的完备性进行评价。通过建立电站锅炉事故应急预案标准事故树,确定各事件权重,将待评价预案中的事件与标准事故树结构进行对比,找出应急预案中缺失的基本事件,并结合事件权重得到量化的应急预案不完备度,以此可得出应急预案的完备度。最后通过实例说明了该方法的有效性,为制定或修订应急预案提供参考。

基于碳足迹核算的电站锅炉减碳路径研究

二氧化碳排放导致的全球变暖问题日益严峻,重点领域节能降碳升级改造不容忽视。电站锅炉作为我国火力发电的主设备之一,拥有着庞大产品系统体系的同时也是重要碳排放领域之一,如何有效降低其碳排放量,寻找产品绿色减碳路径是电站锅炉制造企业关注的重点问题。本研究利用生命周期评价(LCA)方法,核算了电站锅炉产品原辅料获取、原辅料运输、产品部件生产制造等生命周期过程的碳排放,研究结果表明某台典型电站锅炉产品从“摇篮到大门”的碳足迹为10.07万tCO_(2)e,其中原辅料获取阶段碳排放占比最多,为70.74%;产品部件生产制造过程次之,碳排放占比为25.75%,原辅料运输阶段的碳排放占比相对最小,为3.51%。结合各阶段碳排放水平以及锅炉产品生产制造过程中的实际情况,提出了强化电站锅炉产品的绿色设计、重视电站锅炉产品的节能生产、重视电站锅炉产品的绿色供应链建设、重视电站锅炉相关企业的数字化管理等多维度减碳路径,进一步促进电站锅炉的绿色低碳可持续发展。

大型电站锅炉受热面焊接技术探讨

本文详细讨论了大型电站锅炉受热面焊接的关键工艺环节和质量控制措施。主要介绍了受热面的焊接过程,包括材料准备、预热处理、自动或半自动焊接技术的应用以及焊接参数的控制等。焊接质量控制措施分为四个子部分:焊接环境控制、焊接变形控制、焊接材料和设备的质量控制、焊接过程的监控与优化,这些措施共同确保了焊接接头的质量和可靠性,是保证大型电站锅炉受热面安全性和可靠性的基础。