Coal proximate analysis parameter are key indicators for evaluating coal quality and guiding processing and utilization. Traditional proximate analysis detection methods, while accurate, are time-consuming, cumbersome, destroy samples, and cannot be detected in real time. This study developed a method that combining Raman spectra with machine learning algorithms to rapidly and accurately predict approximate analytical parameters of coal samples. Sixty-four widely representative coal samples were collected to acquired their Raman spectra and proximate analysis parameters. Data augmentation techniques increased the sample number and enhanced the model’s generalization capability. The correlation between different moisture, ash, and volatile matter contents in coal and their Raman spectral characteristics was investigated, and advanced machine learning algorithms were further used to analyzed the data. The prediction performance of linear and nonlinear traditional machine learning models was compared with those of the 1D-CNN model. The results show that the 1D-CNN model demonstrated superior overall performance metrics compared to traditional models, with the R2 value of the prediction parameters greater than 0.987 and the RMSE value less than 3.442. The results indicated that this method can rapidly and accurately predict coal quality parameters, which provides technical support for accurate monitoring of coal quality and production optimization.

Online coal quality monitoring is essential for developing more advanced thermal power plants. This study employed a novel thermogravimetric device based on concentrating photothermal heating to investigate the rapid combustion characteristics of 40 coal samples under high heating rates (1000 degrees C/min). Results showed that compared to conventional combustion (heating rate of 10 degrees C/min), the combustion rate significantly increased under high heating rates, accompanied by a notable thermal hysteresis effect. Additionally, peak temperatures during rapid combustion substantially increased, while activation energies significantly decreased. Subsequently, thermogravimetric parameters (SA, SB, SC, SD) were defined based on rapid combustion curves, revealing clear correlations with coal quality parameters (Mad, Vad, FCad, Aad). By combining artificial neural network (ANN) models with the SHAP (SHapley Additive explanation) explainability analysis algorithm, the feasibility of rapid and accurate coal quality prediction based on combustion characteristics was evaluated, with in-depth explanations of relationships between combustion characteristics and coal quality parameters. Results demonstrated that ANN5, using thermogravimetric parameters, peak temperatures, transition times, and activation energy as inputs, achieved optimal prediction performance with maximum errors within 1%. This proves that concentrating photothermal rapid combustion technology has tremendous potential for online coal quality monitoring. Finally, an intelligent combustion optimization system with online coal quality monitoring capability for actual power plants is proposed, potentially completing the entire detection process within 3 min, thereby guiding combustion operation control in power plant boilers.

[Objectives]Under the background of the"dual carbon"strategic goal,the demand for flexible regulation resources in the power system has significantly increased after the large-scale integration of new energy generation into the grid.At present,the coal-fired power is the main flexible resource on the power side with the ability to scale up peak shaving.Since 2016,the major domestic power generation companies have implemented a certain scale of flexibility transformation of coal-fired power units.Therefore,it is necessary to summarize and analyze the problems existing in the actual operation and maintenance of the unit after flexibility transformation.[Methods]The technical route,investment cost and actual operation of several coal-fired power units with flexible transformation in a company were statistically analyzed.[Results]After the flexibility improvement and transformation of the active coal-fired power generation unit,the minimum power generation output of the advanced unit can be reduced to 18%Pe(Pe is rated load)level,the load change rate with 20%Pe～30%Pe can reach 1.8%Pe/min,and an average unit capacity investment is 101 yuan/kW.In addition,under flexible operating conditions,the coal consumption of coal-fired power units after the transformation has significantly increased.[Conclusions]Suggestions are put forward for the operation,maintenance and further work of coal-fired power units under flexible operating conditions.The research results provide reference and inspiration for the flexibility improvement and transformation of existing coal-fired power units.

A series of MnOx/SAPO-34 was synthesized using deposition-precipitation method with acid, alkali, saline to modify their physicochemical property enhancing the performance for toluene oxidation. The structure-activity relationship was explored in depth using variant instruments. It was found that the SAPO-34 was etched by desiliconization with oxalic acid as precipitant and converting its micropores into mesopores as well as macropores, which is not only conducive to anchoring and dispersion of more active MnOx, but also promote the mass transfer of reactants. Meanwhile, the catalyst derived from oxalic acid possesses abundant redox sites with the strongest low temperature reducibility. As the results, the Mn/S34-OA exhibits the best performance of toluene oxidation with T-90=237 degrees C and similar to 100 % CO2 selectivity. Besides, the catalyst maintained long-term stability even in presence of H2O at 260 degrees C. Furthermore, the reaction mechanism is revealed by in-situ DRIFTS experiments. It is demonstrated that lattice oxygen directly participates in oxidation of toluene as the crucial active component in path of toluene to benzyl alcohol to benzaldehyde to benzoic acid to CO2 finally. In addition, the consumed lattice oxygen is replenished by adsorbed gaseous O-2, which is the key to maintain continuous reaction cycle.

为满足新型超超临界对冲旋流燃烧锅炉首次大修后启动要求,同时针对锅炉最上层燃烧器烧损问题,开展了基于锅炉运行安全的冷态优化试验研究,主要包括一次风调平、磨煤机冷态通风阻力测试,以及炉内贴壁风、燃烧器冷却风、内外二次风冷态优化和燃烧器飘带试验.试验结果表明:该类对冲旋流燃烧锅炉仅通过调节较少一次粉管可调缩孔,就能满足一次风风速调平要求;锅炉CF层左右侧贴壁风挡板具有良好的调节特性,但在不同挡板开度下水冷壁贴壁风风速整体偏小;CF燃烧器冷却风随着风门挡板开度增大,风速增长缓慢;F6燃烧器飘带试验显示飘带易卷吸至燃烧器喷口.建议锅炉运行中增加各层贴壁风、燃烧器冷却风及外二次风挡板开度,以预防水冷壁高温腐蚀、冷却风量不足及外二次风旋流强度过大等问题,提高锅炉设备运行安全性.

In order to realize the full-time denitration of a boiler, high-temperature flue gas needs to be introduced when SCR is conducted during the boiler start-up stage, and there is a fire risk due to the presence of combustible fly ash at this time. Therefore, research on reburning and the explosion risk of tail flue gas encountering high-temperature flue gas during start-up and shutdown was carried out. A small testbed was designed to record the temperature of the flue gas and the composition of the flue gas before and after the test, and the ignition characteristics of combustible fly ash in the flue gas were systematically studied. The ignition temperature of combustible fly ash in various conditions was obtained, the ignition characteristics of combustible fly ash in the airflow were analyzed, and the effects of combustible gas, high-temperature flue gas temperature, and fly ash composition on ignition were also analyzed. The results show that the flue gas temperature in the test section was about 400 °C, the low-temperature flue gas temperature increased from 650 °C to 813 °C, and the combustible fly ash did not ignite regardless of whether alcohol was added as a combustible gas component. When the volatile content of combustible fly ash was 10~26.7%, the ignition temperature was 660~760 °C. The lower the volatile content of combustible fly ash was, the higher the ignition point was. When alcohol was added as a combustible component of gas, the ignition point decreased by about 50 °C. The critical ignition temperature of combustible fly ash in this test was lower than that under actual power plant operation conditions.

研究了我国15种典型原煤的PL-Raman光谱,提出了3个能代表光谱特性的特征参数,建立了特征参数与水分、挥发分的质量分数以及燃烧着火温度和燃尽温度的定量关联,并提出了基于PL-Raman光谱分析的煤质快速检测方法.结果表明:煤的荧光特性由水分和挥发分的质量分数共同决定,随着水分和挥发分质量分数的增加,荧光特性显著增强;特征参数与煤中的挥发分质量分数、碳氢质量比和燃烧特征温度间存在良好的数学关联,相关系数较高,可用于煤质特性和燃烧特性的快速检测.

针对W火焰锅炉运行中热效率偏低问题,对燃用的烟煤、石油焦、越南无烟煤等主要煤种开展配煤掺烧,以降低燃料成本、提高锅炉效率.从燃用煤质适应性分析、W火焰锅炉燃烧过程数值模拟和混煤掺烧优化试验3方面,研究了石油焦和越南无烟煤不同掺混比例下热解和燃烧过程特性,制定了掺烧策略并通过燃烧过程模拟研究和掺烧优化试验找到了合适的配煤掺烧方法,解决了锅炉效率低、飞灰含碳量较高、锅炉排烟温度高等问题,实现了节能降耗、提高经济效益的目的.

以新疆某660 MW超临界发电机组为例,介绍为实现新能源配套建设而进行的火电机组柔性改造项目,进行最低稳燃负荷试验,针对现存问题提出灵活性改造方案,设计配套新能源方案并进行财务评价.结果显示:机组最低稳燃负荷为132 MW(20％额定负荷),机组存在脱硝装置入口烟温低、空预器硫酸氢氨跨层凝结、运行氧量大、氨逃逸率高、汽轮机末级叶片水蚀、AGC自动无法投入等问题.灵活性改造过程中,对锅炉部分、汽轮机部分、热控部分等进行优化.灵活性改造完成后,机组运行状况良好,最低稳燃负荷由40％额定负荷降至20％额定负荷,新增132 MW深度调峰调节能力,配套的新能源规模为风电158.4 MW、光伏39.6 MW.灵活性改造项目和配套新能源项目的资本金内部收益率为9.84％.新能源资源丰富的区域可以考虑推广该方法以大力推进火电灵活性改造工作.

针对某电厂两台燃煤机组煤耗数据偏差较大问题,对两台机组发电、供电煤耗进行对比评估.通过查验机组运行参数、入炉煤煤质数据、灰渣可燃物、掺配方案、机组指标统计表等数据,基于能耗指标数据,采用耗差法对煤耗影响因素进行分析,同时采用正平衡修正法对供电煤耗数据进行分析和修正计算,最后得出相关结论.

通过对某330 MW锅炉排烟温度DCS值偏差大、排烟温度偏高原因进行分析,并对空气预热器检修效果进行了评估.对于排烟温度偏差问题,主要从温度标定、燃烧偏差及空气预热器换热效果等方面进行分析.结果表明:DCS排烟温度平均数据能较好反映空气预热器出口截面温度数据,炉右侧排烟温度DCS值偏差大的原因为炉右侧烟道靠右DCS值与实测值存在较大负偏差;330 MW负荷下空气预热器检修后与检修前相比,空气预热器烟气侧换热效率降低约0.5％,排除空气预热器漏风率变化对排烟温度的影响,检修后比检修前空气预热器出口烟气平均温度(修正后)升高约3.0 ℃.建议从空气预热器更换的换热元件材质、间隙或安装工艺等方面查找原因,以解决空气预热器检修无效的问题.

以国内某600 MW墙式切圆燃烧锅炉为研究对象,在炉膛关键区域布置了高温CO在线监测系统,通过试验与数值模拟计算,研究了炉膛CO生成特性与锅炉效率及NOx排放的关联特性,并建立了低氮综合燃烧指数,以平衡锅炉高效燃烧与低氮排放之间的矛盾.研究结果表明,该锅炉效率随监测的炉膛CO浓度增大呈现先增大后减小的趋势,炉膛NOx排放浓度随炉膛CO浓度的增大而逐渐降低;锅炉CO生成特性与锅炉效率及NOx排放均表现出了显著相关性,优化炉膛CO生成特性能够使得锅炉燃烧效率与氮氧化物排放的综合性能实现优化.锅炉实际运行中,可通过监测与调控炉膛CO浓度,获得低氮综合燃烧指数最大值,以有效平衡锅炉效率与NOx排放之间的矛盾,实现锅炉的高效、低氮运行.

High temperature, rapid heating rate and application potential of special reaction conditions (high pressure, high humidity, corrosive atmosphere) made the concentrating photothermal reactor (CPR) become a hot spot in the thermal experimental research. By the 1930s, the concepts of radical reactions and thermal equilibrium concepts had contributed to the formation of theoretical basis of coal combustion. The application of concentrating photothermal reactor in coal combustion research had provided a new perspective for this traditional subject. This paper introduced the structure and characteristics of concentrating photothermal reactor, and summarized the latest research results on the influence of heating rate, oxygen concentration and biomass addition on coal combustion. A potential frontier research direction - pressurized combustion based on concentrating photothermal reactor was also proposed.

Different chars with various cooling rates were obtained in the novel concentrating photothermal reactor to investigate the influence of cooling rate on the structure and combustion reactivity of char. The chars were prepared at 900°C with holding time of 10s, 30s and 120s, respectively. Subsequently, the cold (ex-situ) chars were prepared from the hot (in-situ) chars by controlling different cooling rates of 180°C/s (fast cooling rate), 30°C/s (sub-fast cooling rate), 6.8°C/s (moderate cooling rate) and 1.3°C/s (slow cooling rate). The ex-situ chars were then employed for the combustion in 30%O2/70%CO2 atmosphere at 900°C for 180s. For comparison, the in-situ char was conducted by instantaneously switching the reaction atmosphere. For the chars with holding time of 10s, the mass fraction of in-situ char was higher than the char yield of ex-situ char, and the char yield was decreased with the decrease of cooling rate. The char yield with slow cooling rate was decreased by 11.16% than that with fast cooling rate. The maximum and average mass loss rate of char in O2/CO2 was decreased as the cooling rate decreased. Reduced influence of cooling rate on the aromatic ring systems of char with holding time of 30s and its reactivity was displayed, while almost no difference of those with holding time of 120s was illustrated. The reactivity was closely related to the chemical structure of the char, but no positive correlation was found between the combustion reactivity and the specific surface area of char. The residues proportion of volatile components was the decisive factor of char reactivity.

针对城镇化发展和生态环境的协调发展关系演变过程,运用熵值法、协调发展模型、变异系数和空间分析等方法,围绕时序和空间2个纬度,探讨河南省18个地市2006—2015年城镇化与生态环境协调发展关系,为制定区域发展战略提供参考.结果表明,河南省城镇化和生态环境发展均呈增长趋势,对发展水平而言,生态环境>城镇化,而增长速率则是城镇化>生态环境;城镇化和生态环境的协调度总体为增长态势,仅有郑州市达到高度协调,其他地市以中度协调和濒临失调发展状态为主;城镇化与生态环境的协调发展基本呈现"西北高、东南低"的空间分布格局,其中西北地区又呈现以郑州市为中心向四周逐渐递减态势;河南省城镇化、生态环境及二者的协调度的空间差异性逐步缩小.

在10 MW级生物质气化耦合燃煤发电工程项目上,考察了当量比、添加蒸汽、掺混秸秆对稻壳气化特性的影响.在当前的实验条件下,随着当量比在0.14 ～0.20的范围内增加时,CO、H2和CH4的体积分数均随之减少,燃气热值和气化效率也随当量比的增大而降低;添加适量蒸汽可以促进CO、H2和CH4及燃气热值的提高,气化效率则随蒸汽量的增加而升高;当秸秆掺混比例逐渐增加时,CO、H2和CH4的体积分数和燃气热值出现了不同程度的下降,气化效率也不断降低.

为解决某330 MW机组配置的FAF22.4-12.5-1型动叶可调轴流式送风机喘振跳闸问题,对机组历史运行数据、风道阻力及风机出力进行分析.结果 表明,送风机喘振的直接原因是,炉膛压力偏高及二次风箱压差偏大导致高负荷时送风机出口风道阻力增大.提出了有效预防送风机喘振的措施,包括运行过程中控制两侧送风机运行参数在合理范围、保持炉膛压力调整为微负压状态和同时保持二次风箱压差控制在规定值内,有效解决了运行过程中送风机喘振问题.

In order to solve the problem of abnormal rise of the differential pressure of the revolving air preheater on 300MW unit, we analysed the causes of abnormal rise of the differential pressure of the air preheater and evaluated performances of control measures, through historical data mining and on-site inspection of the unit. The results show that, with the gradual decrease of environment temperature with the decrease of the exhaust gas temperature, the ashes in flue gas are bound by acid liquid produced by condensation of flue gas, and the adhesion areas of the ammonium bisulfate produced in the denitration process are enlarged. However the original set ash blowing pressure can no longer satisfy the requirements of the air preheater, giving rise to the differential pressure of the air preheater on both sides to rise. The reason of the higher differential pressure of the unilateral air preheater is that the large ammonia injection amount, leading to the increases of ammonia escape of the denitrification system. So the side of the air on preheater ammonium bisulfate type blockage is more serious. After the Measures of Adjusting distribution coefficient of ammonia supply valve on both sides, increasing the dust blowing frequency and pressure of the air preheater, the differential pressure of air preheater on both sides are close to the consistent. The decrease amplitude of the differential pressure of the air preheater on 280MW is about 300-500Pa.

对某燃煤电厂正平衡供电煤耗统计值同比异常升高的问题进行原因分析和修正计算.研究主要通过查验日耗煤量、日发电量、机组指标统计表等相关历史数据,基于机组能耗小指标数据对供电煤耗影响进行耗差分析.同时对机组月均供电煤耗进行采样、化验、计量及统计过程进行修正,得到了供电煤耗修正值的区间.对相近工况的2台机组月均能耗小指标同期数据进行耗差分析得出,炉侧影响供电煤耗约6.26 g/(kW·h),机侧影响供电煤耗约1.83 g/(kW·h);采样、化验、计量及统计过程影响供电煤耗约4.10～4.80 g/(kW·h).正平衡月均供电煤耗同比异常升高的原因为炉侧及机侧小指标耗差、入炉煤热值计量及统计过程中的误差.对入炉煤采制化设备存在的问题提出了相关建议,确保入炉煤采制化的精度.

为有效评价生物质气化耦合燃煤锅炉系统能量转换过程,分析该系统的节能潜力,以某10 MW循环流化床生物质气化炉耦合大型超临界燃煤机组为例,建立了该耦合系统的(火用)分析控制体模型,利用Aspen plus平台对该系统实际运行过程进行(火用)平衡分析.结果 表明:当前运行工况下,生物质气化过程(火用)损失是耦合系统最大的(火用)损失,达到42.28％,其次是可燃气体在燃煤锅炉内的燃烧及传热过程,为25.32％.因此系统运行过程中应采取优化运行措施,减小气化过程(火用)损失,同时气化炉应尽量与高参数的大型机组耦合运行,可燃气体选取在燃煤锅炉合适位置输入,以保证充分燃烧.