We propose a simplified mathematical model to describe and to predict the performance of a circulating fluidized bed boiler under varying loads. The model is a systematic approach for modeling a circulating fluidized bed boiler, which is a combination of zero-dimensional energy and mass balance model of heat exchanger blocks. Blocks of heat exchangers are integrated with the air–gas side, the water–steam side, and the solids side. Validation has been carried out by comparing calculated results with experimental data of a pilot-scale circulating fluidized bed boiler. In order to expand throughout the actual operating range, a correlation between the solids circulation rate and the superficial velocity was drawn, and overall heat transfer rates at varying loads were interpreted as representative heat transfer coefficients related with the suspension density. Boiler efficiencies and temperatures were predicted at the loads. Finally, partial load behavior of the boiler was investigated by characterizing performance parameters. This simulation model is hoped to improve the understanding of the boiler performance when operation parameters are selected.
BasuP. Combustion and gasification in fluidized beds, Boca Raton: Taylor & Francis, 2006.
2.
GierseMLecknerB. Operation control of circulating fluidized bed boilers. Int J Energy Res1996; 20: 839–851.
3.
YangHZhangHYangS. Effect of bed pressure drop on performance of a CFB boiler. Energy Fuels2009; 23: 2886–2890.
4.
CaiJMaXLiQ. On-line monitoring the performance of coal-fired power unit: A method based on support vector machine. Appl Therm Eng2009; 29: 2308–2319.
5.
SavolaTKeppoI. Off-design simulation and mathematical modeling of small-scale CHP plants at part loads. Appl Therm Eng2005; 25: 1219–1232.
6.
BasuP. Combustion of coal in circulating fluidized-bed boiler: A review. Chem Eng Sci1999; 54: 5547–5557.
7.
WeissVScholerJFettFN. Mathematical modeling of coal combustion in a CFB reactor. In: Circulating fluidized bed technology II., Oxford: Pergamon Press, 1988, pp. 289–298.
8.
BernardiIDe MarcoAPrandoniW. Modelling and simulation of a power plant equipped with a circulating fluidized bed boiler. In: Circulating fluidized bed technology III., Oxford: Pergamon Press, 1991, pp. 539–544.
9.
ChenYGouX. Dynamic modeling and simulation of a 410 t/h pyroflow CFB boiler. Comput Chem Eng2006; 31: 21–31.
10.
WangQLuoZLiX. A mathematical model for a circulating fluidized bed (CFB) boiler. Energy1999; 24: 633–653.
11.
BasuPSettAGbordzoeEAM. A simplified model for combustion of carbon in a circulating fluidized bed combustor. In: FBC comes of Age FBC comes of Age, New York: ASME, 1987, pp. 738–742.
12.
Saraiva PC, Azevedo JLT and Carvalho MG. Modeling combustion, NOx emissions and SO2 retention in a circulating fluidized bed. In: Proceeding of the 12th international conference on fluidized bed combustion. New York: ASME, 1993, pp.375–380.
13.
Hannes JP, Renz U and Van den Bleek CM. The IEA model for circulating fluidized bed combustion. In: Proceeding of the 13th international conference on fluidized bed combustion. Orlando: ASME, 1995, pp.287–296.
14.
DasABhattacharyaSC. Circulating fluidized bed combustion. Appl Energy1990; 69: 227–246.
15.
HuilinLGuangboZRushanB. A coal combustion model for circulating fluidized bed boilers. Fuel2000; 79: 165–172.
16.
WangSLuHZhaoY. Numerical study of coal particle cluster combustion under quiescent conditions. Chem Eng Sci2007; 62: 4336–4347.
17.
GungorA. Two-dimensional biomass combustion modeling of CFB. Fuel2008; 87: 1453–1468.
18.
WischnewskiRRatschowLHartgeEU. Reactive gas–solids flows in large volumes—3D modeling of industrial circulating fluidized bed combustors. Particuology2010; 8: 67–77.
19.
WertherJHartgeEURatschowL. Simulation-supported measurements in large circulating fluidized bed combustors. Particuology2009; 7: 324–331.
20.
ZhouWZhaoCDuanL. Two-dimensional computational fluid dynamics simulation of coal combustion in a circulating fluidized bed combustor. Chem Eng J2011; 166: 306–314.
21.
XuGSunGNomuraK. Two distinctive variational regions of radial particle concentration profiles in circulating fluidized bed risers. Powder Technol1999; 101: 91–100.
SubbaraoDBasuP. A model for heat transfer in circulating fluidized beds. Int J Heat Mass Transfer1986; 29: 487–489.
24.
DuttaABasuP. An improved cluster-renewal model for estimation of heat transfer coefficient on the water-walls of commercial circulating fluidized bed boilers. J Heat Transfer2004; 126: 1040–1043.
25.
BasuPNagP. Heat transfer to walls of a circulating fluidized-bed furnace. Chem Eng Sci1996; 51: 1–26.
26.
ChengLCenKNiM. Thermal calculation of a circulating fluidized bed boiler furnace. Proc CSEE2002; 22: 146–151. Chinese).
27.
MathisenKWMorariM. Dynamic models for heat exchangers and heat exchanger networks. Comput Chem Eng1994; 18: s459–s463.
28.
BasuPCenKJestinL. Boilers and burners—design and theory, New York: Springer-Verlag, 2000.
29.
DimianACBildeaCS. Chemical process design: Computer-aided case studies, Weinheim: Wiley-VCH, 2008.
30.
LecknerBSzentannaiPWinterF. Scale-up of fluidized-bed combustion—a review. Fuel2011; 90: 2951–2964.
BasuPNagP. An investigation into heat transfer in circulating fluidized beds. Int J Heat Mass Transfer1987; 30: 2399–2409.
33.
DuttaABasuP. An experimental investigation into the heat transfer on wing walls in a circulating fluidized bed boiler. Int J Heat Mass Transfer2002; 45: 4479–4491.
34.
BreitholtzCLecknerBBaskakovAP. Wall average heat transfer in CFB boilers. Powder Technol2001; 120: 41–48.
35.
GolrizMRSundenB. An experimental investigation of thermal characteristics in a 12-MWth CFB boiler. Exp Heat Transfer1994; 7: 217–233.
36.
ZukauskasA. Heat transfer from tubes in crossflow. Adv Heat Transfer1972; 8: 93–160.
