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核心向量机的电站锅炉NO_x排放特性大数据建模 被引量:22
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作者 周昊 丁芳 +1 位作者 黄燕 周康 《中国电机工程学报》 EI CSCD 北大核心 2016年第3期717-722,共6页
为克服传统燃烧优化算法受制于小样本建模的缺点,提出了一种基于大规模数据的NOx排放特性建模方法。应用核心向量机(core vector machine,CVM)对11660组实验数据、共77维运行参数建立了超超临界锅炉的NOx排放特性模型,并对模型参数C和... 为克服传统燃烧优化算法受制于小样本建模的缺点,提出了一种基于大规模数据的NOx排放特性建模方法。应用核心向量机(core vector machine,CVM)对11660组实验数据、共77维运行参数建立了超超临界锅炉的NOx排放特性模型,并对模型参数C和ε进行优化,选定模型参数组(C,ε)为(105,6×10-6),得到了较短的建模时间和较高的预测精准度。同时将建立的CVM模型与其他常见算法支持向量机(support vector machine,SVM)和SVMLight进行性能对比,结果表明,CVM具有优越的收敛速度和更强的泛化能力,随着建模数据量的增加,CVM模型预测准确度有所提升,在建模时间上表现平稳,相对于其余2种算法具有显著优势。 展开更多
关键词 电站锅炉 大规数据 核心向量机 nox建模 燃烧优化
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基于GA-BP的电站锅炉NO_x排放特性建模研究
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作者 陈卓 安恩科 《能源研究与信息》 2010年第4期198-205,共8页
NOx排放模型是电站锅炉实时控制系统的基础。针对普通BP神经网络建模方法收敛速度慢和易陷于局部极值点的问题,提出基于遗传算法(GA)优化BP神经网络的建模方法。通过电站锅炉热态试验获取样本数据,对BP网络隐节点数进行优化后,建立了GA... NOx排放模型是电站锅炉实时控制系统的基础。针对普通BP神经网络建模方法收敛速度慢和易陷于局部极值点的问题,提出基于遗传算法(GA)优化BP神经网络的建模方法。通过电站锅炉热态试验获取样本数据,对BP网络隐节点数进行优化后,建立了GA-BP模型。相比BP神经网络模型,该模型训练时间短,拟合误差大大降低。仿真试验表明:GA-BP模型性能得到改善,泛化能力明显提高,能准确预测NOx排放。GA-BP模型可为运行人员提供指导,也可作为电站锅炉实时控制系统的基础模型。 展开更多
关键词 BP神经网络 遗传算法 nox建模 泛化能力
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Explicit diagnosis of the local ozone production rate and the ozone-NOx-VOC sensitivities 被引量:37
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作者 Zhaofeng Tan Keding Lu +10 位作者 Huabin Dong Min Hu Xin Li Yuhan Liu Sihua Lu Min Shao Rong Su Haichao Wang Yusheng Wu Andreas Wahner Yuanhang Zhang 《Science Bulletin》 SCIE EI CSCD 2018年第16期1067-1076,共10页
In the troposphere, ozone is a harmful gas compound to both human health and vegetation. Ozone is produced from the reaction of NO_x(@NO + NO_2) and VOCs(volatile organic compounds) with light. Due to the highly nonli... In the troposphere, ozone is a harmful gas compound to both human health and vegetation. Ozone is produced from the reaction of NO_x(@NO + NO_2) and VOCs(volatile organic compounds) with light. Due to the highly nonlinear relationships between ozone and its precursors, proper ozone mitigation relies on the knowledge of chemical mechanisms. In this study, an observation-based method is used to simulate ozone formation and elucidate its controlling factors for a rural site on the North China Plain. The instantaneous ozone production rate is calculated utilizing a box model using the dataset obtained from the Wangdu campaign. First, the model was operated in a time-dependent mode to calculate the ozone production rate at each time stamp. The calculated ozone formation rate showed a diurnal average maximum value of 17 ppbv/h(1-h diurnal averaged). The contribution of individual peroxy radicals to ozone production was analyzed. In addition, the functional dependence of calculated P(O_3) reveals that ozone production was in a NO_x-limited regime during the campaign. Furthermore, the missing peroxy radical source will further extend NO_x-limited conditions to earlier in the day, making NO_xlimitation dominate more of a day than the current chemical model predicts. Finally, a multiple scenarios mode,also known as EKMA(empirical kinetic modeling approach), was used to simulate the response of P(O_3) to the imaginary change in precursor concentrations. We found that ozone production was in the NO_x-limited region. However, the use of NO_2 measured by the molybdenum converter and/or the absence of a peroxy radical source in the current chemical model could over-emphasize the VOC-limited effect on ozone production. 展开更多
关键词 Observational-based model Instantaneous ozone production rate (empirical kinetic modeling approach) EKMA
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Computational Modelling of Retrofitting a Coal Fired Boiler Type OP-230 for Predicting NOX Reduction 被引量:2
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作者 MOTYL Przemyslaw LACH Jan 《Journal of Thermal Science》 SCIE EI CAS CSCD 2018年第5期433-439,共7页
This study focuses on a CFD modelling of biomass-derived syngas co-firing with coal in an older mid-sized PC-fired boiler of type OP-230 with low-emission burners on the front wall. The simulations were performed to d... This study focuses on a CFD modelling of biomass-derived syngas co-firing with coal in an older mid-sized PC-fired boiler of type OP-230 with low-emission burners on the front wall. The simulations were performed to determine whether the boiler can be retrofitted for the fulfilment of the prospective environmental protection regulations relating to levels of NO_X emissions. The improvement of the air staging via the dual-fuel technique was based on the indirect co-firing technology. The impact of two arrangements of dedicated syngas nozzles(below and above the existing coal burners), two syngas compositions and two heat replacements(5% and 15%) on the course of thermal processes in a furnace was tested. The reductions in NO_X emissions were predicted relative to the baseline when only coal is combusted. The highest reduction of about 38% was achieved with the syngas nozzles below the existing coal burners and 15% heat replacement. This arrangement of nozzles offers the residence time sufficient to co-fire coal with waste derived syngas. A lower reduction in NO_X emissions was obtained with the nozzles above the burners as the enlargement of local fuel rich zone near syngas injection becomes significant for 15% heat replacement. Results provide for the decreasing impact of methane content along with the increase of syngas heat input. The avoided CO_2 emissions through the syngas indirect co-firing with coal in the boiler are linear function of heat replacements. 展开更多
关键词 boiler modelling CO-FIRING biomass derived syngas nox emission retrofitting
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