scholarly journals Coal combustion modelling in a frontal pulverized coal-fired boiler

2018 ◽  
Vol 46 ◽  
pp. 00010
Author(s):  
Paweł Madejski

The paper presents results of numerical modelling of pulverized coal combustion process in the coal-fired boiler. In the numerical model, coal combustion process includes particle heating, devolatilization, char combustion, as well as turbulent flow and radiative heat transfer was modelled. Presented modelling results were carried out using the Open Source CFD code - Code_Saturne created and developed by EDF R&D and were used to study the combustion of coal in power plant boiler with the objective of simulating the operational conditions and identifying factors of inefficiency. The behaviour of the flow of air and pulverized coal through the burners was modelled, and the three-dimensional flue gas flow through the combustion chamber and heat exchangers was reproduced in the simulation.

Author(s):  
P. V. Narendra Kumar ◽  
Ch. Chengaiah ◽  
P. Rajesh ◽  
Francis H. Shajin

In this paper presents a hybrid method for optimization process of combustion in power plant boiler. ANSSA scheme will be joint implementation of Artificial Neural Network (ANN) as well as Salp Swarm Optimization Algorithm (SSA) known ANNSSA. Here, ANN training process will be enhanced by using the SSA calculating. The optimization of economic parameters reduces excess air level and performs combustion efficiency at boiler system. Due to the operation of service boiler, oxygen content of flue gases is one of the significant factors which influence the efficiency of boiler, and influence each other to other thermal parameters of economic like temperature of flue gases combustion, unburned carbon at fly ash slag and consumption of coal power supply. The combustion performance denotes a saving at operating costs of boiler. ANNSSA method evolved for process of combustion to enhance the implementation and efficiency of the power plant boiler. At that time, ANNSSA technique is implemented at MATLAB/Simulink work platform as well as implementation is evaluated using existing techniques.


2014 ◽  
Vol 543-547 ◽  
pp. 854-857
Author(s):  
Jiang Ming Ye

It is very important to study the emission of pollutant from a coal combustion device, and it is a best way to adopt numerical simulation for such a study. By using a mathematical model with a post-processing method and based on combustion simulation, this paper calculates the SOx distribution in a power plant boiler furnace. For the formation of SOx, a conventional chemical reaction model is adopted, and according to the principles of reaction dynamics, a model for the SOx formation is also put forward. It is the first time for preceding the calculation and on-site testing an 800MW-unit boiler in China. The test and calculation results show that the model is reasonable, and such a study will be valuable as a reference to the boiler design and its clean operation.


2014 ◽  
Vol 955-959 ◽  
pp. 2177-2181
Author(s):  
Wen Yan Li ◽  
Shi Yong Wang ◽  
Xiao Ming Wang

The structure and arrangement of flue and deflector modules have significant influences on flue gas flow field and distribution of NH3 concentration in a SCR reactor. Numerical calculations about distributions of velocity, NH3 concentration and flow resistance in the deNOx reactor of a 1000MW power plant boiler with CFD have provided the optimal combination of layout scheme of guide plates. A1:15 experimental model of the reactor was constructed based on the principles of similarity theory, and cold model test was carried out with air substituting for flue gas, and CO for NH3.The consequences of model test and numerical modeling were basically similar and met the design requirements. Moreover, deposition characteristics of the experimental model was studied with fly ash from coal-fired boiler, which demonstrated that deposition was not severe under both 50% and 100% boiler full load. The model experiments indicated that the optimum program could achieve purpose of the flow field optimization.


2017 ◽  
Vol 21 (suppl. 3) ◽  
pp. 597-615 ◽  
Author(s):  
Srdjan Belosevic ◽  
Ivan Tomanovic ◽  
Nenad Crnomarkovic ◽  
Aleksandar Milicevic

A cost-effective reduction of NOx emission from utility boilers firing pulverized coal can be achieved by means of combustion modifications in the furnace. It is also essential to provide the pulverized coal diffusion flame control. Mathematical modeling is regularly used for analysis and optimization of complex turbulent reactive flows and mutually dependent processes in coal combustion furnaces. In the numerical study, predictions were performed by an in-house developed comprehensive three-dimensional differential model of flow, combustion and heat/mass transfer with submodel of the fuel- and thermal-NO formation/ destruction reactions. Influence of various operating conditions in the case-study utility boiler tangentially fired furnace, such as distribution of both the fuel and the combustion air over the burners and tiers, fuel-bound nitrogen content and grinding fineness of coal were investigated individually and in combination. Mechanisms of NO formation and depletion were found to be strongly affected by flow, temperature and gas mixture components concentration fields. Proper modifications of combustion process can provide more than 30% of the NOx emission abatement, approaching the corresponding emission limits, with simultaneous control of the flame geometry and position within the furnace. This kind of complex numerical experiments provides conditions for improvements of the power plant furnaces exploitation, with respect to high efficiency, operation flexibility and low emission.


2021 ◽  
Vol 40 (1) ◽  
pp. 131-140
Author(s):  
Juanjuan Jiang ◽  
Rong Zhu ◽  
Shengtao Qiu

Abstract CO2 injection into blast furnace tuyeres is a new technology to utilize CO2, aiming at expanding the way of CO2 self-absorption in the metallurgical industry. The decisive factor of whether CO2 can be mixed into a blast-furnace hot blast and the proper mixing ratio is the effect of CO2 injection on pulverized coal burnout. To investigate the effect of CO2 injection into tuyeres on pulverized coal burnout, a three-dimensional mathematical model of pulverized coal flow and combustion in the lower part of the pulverized coal injection lance-blowpipe-tuyere-raceway was established, and the effect of CO2 injection into tuyeres on pulverized coal combustion rate and outlet temperature is analyzed. The numerical simulation results show that the delay of pulverized coal combustion in the early stage is caused by the endothermic effect of the reaction of CO2 with carbon, and the burnout of pulverized coal is increased in the later stage due to the oxidation of CO2.


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