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Zhang Y.,Special Equipment Safety Supervision Inspection Institute of Jiangsu Province | Zhang J.,Nanjing Southeast University
Dongli Gongcheng Xuebao/Journal of Chinese Society of Power Engineering

Taking Lijiata and Jinjie bituminous char as the object of study, the characteristics of NO-char reaction in high-CO2 concentration atmosphere were investigated in a fixed-bed reactor, so as to analyze the effects of following factors on the NO reduction by char, such as the reaction atmosphere, CO2 concentration, O2 concentration, initial NO concentration and the pyrolysis temperature, etc. Results show that high concentration of CO2 existing in reaction atomphere is detrimental to the NO reduction by char, and with the rise of CO2 concentration, the effect becomes more obvious. At low reaction temperatures, the presence of O2 in reaction atmosphere has a certain promotion effect on the reduction of NOx whereas at high temperatures, it's the opposite. The reduction rate of NO reduces with the increase of initial NO concentration. The reactivity of char decreases with increasing pyrolysis temperature. ©, 2015, Shanghai Power Equipment Research Institute. All right reserved. Source

Hu S.-B.,Special Equipment Safety Supervision Inspection Institute of Jiangsu Province
Petrochemical Equipment

According to the complex and non-deterministic characteristics of the static sealing system influencing factors, combined with historical data and the experts experience, this method is presented to analyses the bolt-flange connection system function and function failures, failure mode, effect and criticality. The reliability centered maintenance (RCM) quantitative analysis method, based on the qualitative analysis and adopting the fuzzy mathematics, is presented to make risk assessment of the bolt flange connection system malfunction. Source

Ye W.,Nanjing University of Science and Technology | Tong Y.,Nanjing University of Science and Technology | Li X.,Special Equipment Safety Supervision Inspection Institute of Jiangsu Province
Zhongguo Jixie Gongcheng/China Mechanical Engineering

Based on energy consumption of a bridge crane in “full life cycle”, this paper put forward bridge cranes energy saving evaluation index system. Rough set theory knowledge was adopted to reduce the index of the bridge crane energy saving evaluation index system. The optimized bridge crane energy saving index system could be obtained after reduction and all index weights were acquired as well. Finally the fuzzy optimization theory was applied to build energy-efficient evaluation model of the bridge crane and this model was used to evaluate the energy consumption of the overhead crane. This paper selected five bridge cranes of different designs and materials and analyzed their advantages as well as disadvantages of power consumption. Via calculation and analyses, the optimal design of energy saving of bridge can be obtained and it may provide a reference for the bridge crane design and manufacturing. Source

Chen S.-T.,Shijiazhuang University | Sun Z.-X.,Shijiazhuang University | Li X.-D.,Special Equipment Safety Supervision Inspection Institute of Jiangsu Province | Wang H.-L.,Shijiazhuang University
Journal of Railway Engineering Society

Research conclusions: (1) The longitudinal and lateral dynamic characteristics are sensitive to the change of linear stiffness ratio of girder hoisting machine leg and main girder line, the change of the linear stiffness ratio will cause the significant changes of the vibration frequency and vibration model. (2) The vertical dynamic characteristics are not sensitive to the change of linear stiffness ratio, but are sensitive to the change of vertical load. (3) To ensure the operation safety of the girder hoisting machine, the dynamic coefficient of lifting must be researched in the process of the transformation. (4) According to the practical engineering for analysis, the research results is suitable for the girder hoisting machine transformation and new equipment design and development.Research purposes: Large-tonnage girder hoisting machine often need to be transformed to meet the engineering environment. The dynamic characteristic change is easily ignored in the conventional transformation, resulting in unnecessary engineering accident. Therefore, based on the linear stiffness ratio of girder hoisting machine leg and main girder line, the influence law of the leg height on dynamic characteristics was systematically analyzed so as to offer the reference for transform and design of the girder hoisting machine. ©, 2014, Journal of Railway Engineering Society. All right reserved. Source

Ma J.,Nanjing Southeast University | Xu F.,Nanjing Southeast University | Huang K.,Special Equipment Safety Supervision Inspection Institute of Jiangsu Province | Huang R.,Nanjing Southeast University

Given the increasingly stringent emission regulations, an accurate model of emission prediction is required for the aftertreatment systems of diesel engines. For example, the selective catalytic reduction system can realize higher accuracy emission control if the mass of nitrogen oxides (NOx) is known. Given its simplicity, convenience, and effectiveness, the method of data-driven modeling has been widely researched and considered a primary method to estimate the NOx mass before it reaches the aftertreatment device of a diesel engine. To fully use the known engine operating data and therefore improve the prediction accuracy, this study proposes and develops a general linear and nonlinear auto-regressive model with exogenous inputs (GNARX) for NOx prediction. A recursive least square algorithm with forgetting factor is given to estimate the model parameters, and a new simulated annealing based pruning algorithm is developed to identify the model structure. The proposed methods are first used to model the simulation and engineering data to validate their effectiveness and superiority in comparison to the conventional methods. Based on gray relational analysis, the main factors that influence NOx formation, such as the net engine torque, turbo speed, and accelerator pedal position, are then determined as the inputs for modeling the NOx emission of the diesel engine. The results show that the modeling and prediction accuracy of the GNARX model are higher than those of other models, which indicates that the GNARX model is feasible to predict NOx emission. © 2016 Elsevier B.V. Source

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