Improvement on Dynamic Combustion Model of Dense-Phase Zone in Circulating Fluidized Bed Boiler Furnace

2005 ◽  
Author(s):  
Weiping Yan ◽  
Xining Yu ◽  
Libao Yin
Keyword(s):  
Circulating Fluidized Bed ◽  
Combustion Model ◽  
Heating Process ◽  
Dense Phase ◽  
Phase Zone ◽  
Boiler Furnace ◽  
Cfb Boiler ◽  
Bed Temperature ◽  
Proposed Model ◽  
Dynamic Combustion

A novel method for predicting the dynamic combustion performances of dense-phase zone in CFB furnace are proposed based on the improvements of the previous models. The coal particle heating process, the time delay and the subsequent heat release as raw coal with wide size distribution admitted into the furnace are adequately taken into account in the proposed model. The bed temperature responses to the variations of coal firing rates are predicted and compared to the measured data from a 220t/h CFB boiler.

A Study of Operation Performance of Circulating Fluidized Bed Combustion Boiler

2003 ◽  
Author(s):  
Zhengshun Wu ◽  
Hanping Chen ◽  
Dechang Liu ◽  
Jie Wang ◽  
Chuangzhi Wu ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Fluidized Bed Combustion ◽  
Operation Performance ◽  
Cfb Boiler ◽  
Bed Temperature ◽  
Suitable Temperature ◽  
Bed Material ◽  
Circulating Fluidized Bed Combustion

The operation performance of circulating fluidized bed combustion (CFBC) boiler was studied in this paper. The experimental results indicate that the load of CFB boiler has linear relation with bed temperature and bed material height of operation. By multiple regression analysis, the relation of the load of CFB boiler with bed temperature and bed material height of operation can be expressed as a formula. The suitable temperature and the bed material height corresponding to the load of CFB boiler can be found using the formula; the problem of the boiler to be blindly operated can be reduced in practice.

Lignite-Fired CFB Boiler SO2, NO Emission Control Technology Research

2014 ◽  
Vol 989-994 ◽  
pp. 256-259
Author(s):  
Jian Meng Yang ◽  
Bi Zheng Wang ◽  
Wei Wang
Keyword(s):  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Emission Control ◽  
Emission Characteristics ◽  
Control Technology ◽  
Technology Research ◽  
Circulating Fluidized Bed Boiler ◽  
No Emission ◽  
Cfb Boiler ◽  
Bed Temperature

For study on SO2 and NO emission characteristics of circulating fluidized bed boiler experiments were carried out in a 300MW circulating fluidized bed boiler. In these experiments, the variables were the amount of limestone and bed temperature. While conducting the test, the reasons for the changes in emission were analyzed, and some advices about combustion adjustment were proposed.

Optimize Selected of Anti-Attrition Ridge Parameters through Numerical Simulation in CFB Boiler Blended with Waste Sludge

2014 ◽  
Vol 525 ◽  
pp. 222-226 ◽  
Author(s):  
Bo Lou ◽  
Hai Liang Diao ◽  
Si Ke Wu
Keyword(s):  
Particle Trajectory ◽  
Circulating Fluidized Bed ◽  
Three Dimensional ◽  
Guangdong Province ◽  
Furnace Wall ◽  
Combustion Model ◽  
Cfb Boiler ◽  
Waste Sludge ◽  
Ring Core ◽  
Stochastic Particle

Combustion in boiler blended with waste sludge can cause serious abrasion in the furnace. In this paper, Fluent6.3 was applied to establish three-dimensional numerical combustion model based on k-ε turbulence equations and Lagrangian stochastic particle trajectory to analyze a CFB (Circulating Fluidized Bed) boiler of a power plant in Guangdong province. The results show that anti-attritions will break the ring-core adherent regurgitation of the particles thus reducing erosion of particles made to the furnace wall. Furthermore, a setting of three anti-attrition ridges can prolongate the life of the wall by 2.49 times. Increasing numbers and the length of ridges are beneficial to wall, which should be limited shorter than 150mm duo to heat tube slagging, and implementing a shape of trapezoid instead of rectangle all are derived as enhancements to the feature of anti-attrition of CFB.

Practice of Deep Desulphurization in a 300MW CFB Boiler

2011 ◽  
Author(s):  
Tinghua Zeng ◽  
Zhigang Zhan ◽  
Jian Fang ◽  
Yi Liu
Keyword(s):  
Flue Gas ◽  
Circulating Fluidized Bed ◽  
Low Grade ◽  
Emission Standard ◽  
Cfb Boiler ◽  
Bed Temperature ◽  
High Sulfur Content ◽  
The Mean ◽  
Low Nox Emission ◽  
Mean Time

Design of the first “300MW Circulating Fluidized Bed (CFB) boiler+limestone/gypsum wet Flue Gas Desulphurization (FGD) system” in the world is introduced, operating parameters of the boiler and FGD system are analyzed. The operating bed temperature is higher than 940°C, efficiency of the boiler is more than 93.5%. In the mean time, SO2 remove efficiency is higher than 95%, and 65% dust remove efficiency is gotten in the FGD system. Practice showed that deep desulphurization and deNOx of CFB boiler has higher SO2 remove efficiency at lower Ca/S ratio compared with traditional inner desulphurization mode, it can meet more and more rigid environmental protection emission standard, and is suitable to more fuels. Deep desulphurization and deNOx of CFB boiler can also realize high temperature CFB boiler which doesn’t aim to inner desulphurization and low NOx emission, and benefits to low-grade, high sulfur content fuels. Research of deep desulphurization and deNOx should be a developing direction for large capacity CFB boiler.

Experimental Study on Technical Difficulties of Botswana First Circulating Fluidized Bed Boiler during Loading Process

2013 ◽  
Vol 721 ◽  
pp. 357-362
Author(s):  
Guang Zeng ◽  
Sen Lin Zhao ◽  
Lai Wei ◽  
Run Ze Huang ◽  
Modiri Badirwang
Keyword(s):  
Fluidized Bed ◽  
Influencing Factors ◽  
Circulating Fluidized Bed ◽  
Stable Operation ◽  
Circulating Fluidized Bed Boiler ◽  
Cfb Boiler ◽  
Full Load ◽  
Loading Process ◽  
Bed Temperature ◽  
Boiler Operation

For study of technical difficulties that make Botswana first CFB (Circulating Fluidized Bed) boiler can’t reach full load at beginning of loading process, first experiments were carried out as awful experimental cases to analyze influencing factors; Second experiments were carried out as tentative experimental cases to select useful solutions; Third experiments were carried out as targeted experimental cases to execute chose solutions. Results indicate that one prominent difficulty during CFB boiler reaching full load is that boiler operation bed temperature was too high which was a comprehensive effect with some other influencing factors. CFB boiler bed temperature MFT (Main Fuel Trip) set point slight increasing, grain size changing of both start-up material and feeding coal, limestone injecting, fluidizing air of seal pot and FBHE appropriate controlling and FBHE (Fluid Bed Heat Exchanger) gradually start working are taken simultaneously, all these effective solutions solve the technical difficulties and accelerate the boiler reach full load, but attentions still need to be paid for the boiler stable operation permanently in future.

Simulation of Circulating Fluidized Bed (CFB) Boiler Oxygen-Enriched Combustion

2012 ◽  
Vol 614-615 ◽  
pp. 139-142
Author(s):  
Yuan Ping Xu ◽  
Hua Zhou ◽  
Qing Yin Jiang
Keyword(s):  
Oxygen Content ◽  
Circulating Fluidized Bed ◽  
Combustion Process ◽  
Combustion Efficiency ◽  
Configuration Software ◽  
Combustion Model ◽  
Cfb Boiler ◽  
Industrial Data ◽  
Real Process ◽  
The Relationship

In this paper, we focus on the relationship between oxygen-enriched combustion efficiency and oxygen content of primary air under N2 /O2 atmosphere combustion on CFB boiler. Firstly, an entirely possible of CFB boiler oxygen-enriched combustion model was proposed. Secondly, a platform was built for simulation of CFB combustion process on XD-APC configuration software. Finally, industrial simulation with industrial data was going on to prove the platform was reasonable. The simulation results were consistent of industrial data. It shows the simulation platform reliability, and the model accuracy. On this basis, coal combustion efficiency was simulated. It shows that the combustion efficiency increases following by oxygen content increasing. It’s economic for real process when oxygen content chooses from 25% to 30%.

Effect of Dilute and Dense Phase Conditions on Bed-to-Wall Heat Transfer Mechanism in the Riser Column of a Circulating Fluidized Bed Combustor

2005 ◽  
Author(s):  
G. Nirmal Vijay ◽  
B. V. Reddy
Keyword(s):  
Heat Transfer ◽  
Circulating Fluidized Bed ◽  
Radiation Heat Transfer ◽  
Transfer Mechanism ◽  
Operating Conditions ◽  
Wall Heat Transfer ◽  
Heat Transfer Mechanism ◽  
Dense Phase ◽  
Radiation Heat ◽  
Bed Temperature

The bed-to-wall heat transfer in the riser column of a circulating fluidized bed (CFB) combustor depends on the contributions of particle convection, gas convection and radiation heat transfer. The percentage contribution of each of these components depends on the operating conditions i.e., dilute and dense phase bed conditions and bed temperature in the riser column. In the present paper, the contribution of particle convection, gas convection and radiation heat transfer components with operating conditions is estimated using the cluster renewal mechanistic model. The present results contribute some fundamental information on bed-to-wall heat transfer mechanism under dilute and dense phase conditions with bed temperature. The results will further aid for better understanding of heat transfer mechanism to water-wall surfaces in the upper region of the riser column.

scholarly journals An Experimental Study on the Characteristics of NOx Distributions at the SNCR Inlets of a Large-Scale CFB Boiler

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1267
Author(s):  
Jin Yan ◽  
Xiaofeng Lu ◽  
Changfei Zhang ◽  
Qianjun Li ◽  
Jinping Wang ◽  
...  
Keyword(s):  
Large Scale ◽  
Circulating Fluidized Bed ◽  
Catalytic Reduction ◽  
Field Tests ◽  
Reduction Process ◽  
Urea Solution ◽  
Phase Zone ◽  
Cfb Boiler ◽  
Low Emission ◽  
First Time

The unknown NOx distributions inside large-scale CFB (circulating fluidized bed) boilers have always hindered the economy of the SNCR (selective non-catalytic reduction) process. In this study, field tests were carried out on a typical 300 MW CFB boiler, where multi-level 316 L-made probe and Ecom-J2KN/Testo 350 analyzers were used to perform detailed two-dimensional distributions of flue gas composition at SNCR inlets for the first time. The penetration depth inside the horizontal flue pass was up to 7 m. The NOx distributions were analyzed in detail combining with the auxiliary test in the dilute phase zone. Key results show that the average O2 concentrations in #A and #C regions were 6.52% and 0.95%, respectively. The vertical NOx distributions of #A and #C SNCR inlets were similar, showing a trend of first increasing and then decreasing with peak value all appeared at 5 m depth, while the NOx distribution of #B SNCR inlet was basically increasing. Some local areas with extremely high NOx concentration (over 2000 mg/m3) were observed near the inclined edge of SNCR inlets, which has never been reported before. Based on this, the optimization of urea injections was conducted, which could save 15.7% of the urea solution consumption while ensuring ultra-low emission of NOx.

Pilot-scale combustion studies with kraft lignin in a powder burner and a CFB boiler

TAPPI Journal ◽  
2010 ◽  
Vol 9 (6) ◽  
pp. 24-30 ◽  
Author(s):  
NIKLAS BERGLIN ◽  
PER TOMANI ◽  
HASSAN SALMAN ◽  
SOLVIE HERSTAD SVÄRD ◽  
LARS-ERIK ÅMAND
Keyword(s):  
Circulating Fluidized Bed ◽  
Black Liquor ◽  
Chloride Content ◽  
Pilot Scale ◽  
High Energy ◽  
Kraft Lignin ◽  
High Energy Density ◽  
Alkali Chloride ◽  
Cfb Boiler ◽  
Solid Biofuel

Processes have been developed to produce a solid biofuel with high energy density and low ash content from kraft lignin precipitated from black liquor. Pilot-scale tests of the lignin biofuel were carried out with a 150 kW powder burner and a 12 MW circulating fluidized bed (CFB) boiler. Lignin powder could be fired in a powder burner with good combustion performance after some trimming of the air flows to reduce swirl. Lignin dried to 10% moisture content was easy to feed smoothly and had less bridging tendencies in the feeding system than did wood/bark powder. In the CFB boiler, lignin was easily handled and cofired together with bark. Although the filter cake was broken into smaller pieces and fines, the combustion was not disturbed. When cofiring lignin with bark, the sulfur emission increased compared with bark firing only, but most of the sulfur was captured by calcium in the bark ash. Conventional sulfur capture also occurred with addition of limestone to the bed. The sulfur content in the lignin had a significantly positive effect on reducing the alkali chloride content in the deposits, thus reducing the high temperature corrosion risk.

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