Computer Simulation about Influence of Flue Gas Recycle and Subsection Air on Nitrogen Oxide Formation to Chain Boiler

2010 ◽  
Vol 171-172 ◽  
pp. 702-705
Author(s):  
Jing Han ◽  
Man Yin Hu ◽  
Xiu Hong Wang

Numerical simulation is used to study the combustion process,temperature distridution and NOx emission for a 10t/h chain boiler with and without flue gas recycle. And at the same time,it is constrasted that differences when flue gas is recycled to the primary wind inlet and to secondry wind inlet.The results show the temperature distridution decreased with flue gas recycle,so there is less NOx emission.And when flue gas is recycled to secondry wind inlet ,the NOx emission dropped mostly. The result offer a reference to design and operate a chain boiler.

2014 ◽  
Vol 1006-1007 ◽  
pp. 181-184
Author(s):  
Zhu Sen Yang ◽  
Xing Hua Liu ◽  
Shu Chen

The combustion process of municipal solid waste (MSW) in a operating 750t/d grate furnace in Guangzhou was researched by means of numerical simulation. The influence of MSW moisture content on burning effect was discussed. The results show that: with the moisture content dropped from 50% to 30%, the heat value could be evaluated from 13.72% to 54.91% and the average temperature in the furnace could be promoted 90-248°C. However, the combustible gases and particle in the flue gas of outlet would take up a high proportion since lacking of oxygen would lead to an incomplete combustion. The excess air coefficient should be increased to 2.043~2.593 in order to ensure the flue gas residence time more than 2s and temperature in the furnace higher to 800°C.


2014 ◽  
Vol 660 ◽  
pp. 397-401 ◽  
Author(s):  
Mohd Fareez Edzuan bin Abdullah ◽  
Mohd Hisyamuddin bin Sulaiman ◽  
Noor Aliah Binti Abdul Majid

This paper discusses the nitrogen oxides (NOx) emission characteristics of compression ignition diesel engine operating on diesel fuel blends with different saturation degrees of biofuel and with methanol. In order to investigate the dominant factor of increased NOx in biofuels, diesel combustion tests were conducted under idling condition and the tailpipe exhaust emissions were measured by a flue gas analyzer. The general trend where NOx emission increased and reduced carbon monoxide (CO) emission in the biofuel and methanol blend cases were observed. The NOx emission levels increased as the biofuel saturation degree decreased, where it may be suggested that the prompt NOx mechanism is significant in total NOx formation of biofuel combustion process.


2014 ◽  
Vol 1030-1032 ◽  
pp. 648-652
Author(s):  
Cai Ying Ban ◽  
Xu Ao Lu ◽  
Jian Meng Yang ◽  
Xu Ran ◽  
Feng Ying Liang

The purpose of this paper is to study the impact of furnace temperature and load after blending in lignite, based on CFD software FLUENT-6.3,this paper choose the appropriate geometry model and the physical and mathematical models, and numerical simulation of the different conditions 600MW supercritical once-through boiler blending lignite furnace combustion process is curried out. And through a 600MW supercritical coal-fired boiler furnace lignite blended performed sections thermodynamic calculation under different conditions, worked out the furnace flue gas temperature, CO, CO2concentration distribute trend and radiant heat each section surface heat load conditions. The specific amount were blended with 5%, 10%, 15%, 20% were not dried lignite and dried lignite 20% after five conditions. And obtained a conclusion is the temperature and radiation heating surface flue gas heat load in the overall trend under the various conditions.


2021 ◽  
Vol 302 ◽  
pp. 01010
Author(s):  
Dararat Laohalertdecha ◽  
Kampanart Theinnoi ◽  
Sak Sittichompoo

Nowadays, global warming is the main environmental problems all over the world. The air pollutants mainly from the burning of fossil fuels and coal in power plants, transportation, and automobiles. There are release major point emission of the atmosphere. The nitrogen oxides are the most relevant for air pollution that contribute to the formation of photochemical smog and acid rain. Numerous methods have been studied to eliminate the nitrogen oxides such as the use low-nitrogen fuels technology, the selective catalytic reduction (SCR), wet scrubbing. The aim of this research is investigated non-thermal plasma (NTP) techniques offer an innovation to eliminate both nitrogen oxide (NOx) and soot emissions from combustion. This study is used to selectively transfer input electrical energy to electrons without expending this in heating the entire gas flow which creates free radicals in the flue gases. The simulated flue gas from combustion process is applied to the system. The results showed that the prototype of nonthermal plasma system is shown the highly efficient of NOx removal was achieved. However, the optimised of NTP operating conditions are required to enhance the NOx reduction activities.


2011 ◽  
Vol 33 (1) ◽  
pp. 1591-1599 ◽  
Author(s):  
Marc S. Day ◽  
John B. Bell ◽  
Xinfeng Gao ◽  
Peter Glarborg

Author(s):  
Xianbiao Yang ◽  
Yuan Gao ◽  
Shutao Wang ◽  
Renqiang Shi ◽  
Shaohua Liang ◽  
...  

2005 ◽  
Vol 122 (3) ◽  
pp. 61-66
Author(s):  
Leszek PIASECZNY ◽  
Ryszard ZADRĄG

Water delivery to the cylinders is one of the ways to reduce the nitrogen oxide formation in a combustion process in CI engine and is justified in published research results. In the aftermath of the admission of the fuel-water emulsion into the engine, along with the reduction of nitrogen oxides, the change in concentration of carbon oxides and particulates, basic engine parameters determining its performance and load of crank-piston assembly can be observed. It the paper, the results of own research of fuel-water emulsion delivery influence on changes of toxic


2021 ◽  
Vol 11 (7) ◽  
pp. 2961
Author(s):  
Nikola Čajová Kantová ◽  
Alexander Čaja ◽  
Marek Patsch ◽  
Michal Holubčík ◽  
Peter Ďurčanský

With the combustion of solid fuels, emissions such as particulate matter are also formed, which have a negative impact on human health. Reducing their amount in the air can be achieved by optimizing the combustion process as well as the flue gas flow. This article aims to optimize the flue gas tract using separation baffles. This design can make it possible to capture particulate matter by using three baffles and prevent it from escaping into the air in the flue gas. The geometric parameters of the first baffle were changed twice more. The dependence of the flue gas flow on the baffles was first observed by computational fluid dynamics (CFD) simulations and subsequently verified by the particle imaging velocimetry (PIV) method. Based on the CFD results, the most effective is setting 1 with the same boundary conditions as those during experimental PIV measurements. Setting 2 can capture 1.8% less particles and setting 3 can capture 0.6% less particles than setting 1. Based on the stoichiometric calculations, it would be possible to capture up to 62.3% of the particles in setting 1. The velocities comparison obtained from CFD and PIV confirmed the supposed character of the turbulent flow with vortexes appearing in the flue gas tract, despite some inaccuracies.


2013 ◽  
Vol 444-445 ◽  
pp. 1574-1578 ◽  
Author(s):  
Hua Hua Xiao ◽  
Zhan Li Mao ◽  
Wei Guang An ◽  
Qing Song Wang ◽  
Jin Hua Sun

A numerical study of premixed propane/air flame propagation in a closed duct is presented. A dynamically thickened flame (TF) method is applied to model the premixed combustion. The reaction of propane in air is taken into account using a single-step global Arrhenius kinetics. It is shown that the premixed flame undergoes four stages of dynamics in the propagation. The formation of tulip flame phenomenon is observed. The pressure during the combustion process grows exponentially at the finger-shape flame stage and then slows down until the formation of tulip shape. After tulip formation the pressure increases quickly again with the increase of the flame surface area. The vortex motion behind the flame front advects the flame into tulip shape. The study indicates that the TF model is quite reliable for the investigation of premixed propane/air flame propagation.


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