Thermodynamic models and energy distribution of single-phase heated surface in a boiler under unsteady conditions

Xiyan GUO, Yongping YANG

PDF(159 KB)
PDF(159 KB)
Front. Energy ›› 2011, Vol. 5 ›› Issue (1) : 69-74. DOI: 10.1007/s11708-010-0117-7
RESEARCH ARTICLE

Thermodynamic models and energy distribution of single-phase heated surface in a boiler under unsteady conditions

Author information +
History +

Abstract

A coal-fired power unit frequently operates under unsteady conditions; thus, in order to acquire scientific energy analysis of the unit, thermodynamic analysis of a single-phase heated surface in a boiler under such conditions requires investigation. Processes are analyzed, and distributions of energy and exergy are qualitatively revealed. Models for energy analysis, entropy analysis, and exergy analysis of control volumes and irreversible heat transfer processes are established. Taking the low-temperature superheater of a 610 t/h-boiler as an example, the distribution of energy, entropy production, and exergy is depicted quantitatively, and the results are analyzed.

Keywords

thermodynamic model / energy distribution / boiler / unsteady conditions

Cite this article

Download citation ▾
Xiyan GUO, Yongping YANG. Thermodynamic models and energy distribution of single-phase heated surface in a boiler under unsteady conditions. Front Energ, 2011, 5(1): 69‒74 https://doi.org/10.1007/s11708-010-0117-7

References

[1]
Guo X Y, Yang Y P, Wang X Y, Yang Z P. Heat distribution in utility boilers operating under unsteady operating conditions. Journal of Power Engineering, 2007, 27(5): 667-671
[2]
Guo X Y, Yang Y P, Wang X Y, Yang Z P. Analysis on effect of heat storage in boiler upon coal consumption of power generating unit. Proceedings of the CSEE, 2007, 27(26): 30-34
[3]
Yang Y P, Guo X Y. A study on transient thermoeconomics theory. First International Conference on Engineering Thermophysics (ICET’99), Beijing, China, 1999, 160-166
[4]
Falcetta M F, Sciubba E. Unsteady numerical simulation of combined cycle plants. Proc. TAISE’97, Beijing, China, 1997, 224-231
[5]
Olslmmer B, von Spakovsky M R, Favrat D. An approach for the time-dependent thermoeconomic modeling and optimization of energy system synthesis, design and operation. Proc. TAISE’97, Beijing, China, 1997, 321-339
[6]
Moran M J, Shapiro H N. Fundamentals of Engineering Thermodynamics. 5th ed. New York: John Wiley & Sons, 2006
[7]
Qiu L J. Operation of Large Steam Turbines. Beijing: China Water and Electric Power Press, 1994 (in Chinese)
[8]
Zhang B H. Life Time Management and Peak-load Operation of Large Capacity Fossil Fuel Power Units. Beijing: China Water and Electric Power Press, 1988 (in Chinese)

Acknowledgements

This study was supported by the National Basic Research Program of China (No. 2009CB219801), the National Natural Science Foundation of China (Grant Nos. 50776028 and 50606010) and the Fundamental Research Funds for the Central Universities.
Notation
Fheat transfer area/m2
Vvolume/m3
mmass/kg
m ˙flow rate of mass/(kg·s-1)
ppressure/Mpa
Tabsolute temperature/K
vspecific volume/(m3·kg-1)
especific internal energy/(kJ·kg-1)
hspecific enthalpy/(kJ·kg-1)
Q ˙time rate of heat transfer/kW
W ˙time rate of work/kW
sspecific entropy/(kJ·kg-1·K-1)
ΔS ˙time rate of enthalpy change/(kJ·s-1·K-1)
exspecific exergy/(kJ·kg-1)
E ˙dtime rate of exergy destruction/kW
E ˙Qtime rate of exergy transfer accompanying heat transfer/kW
Greek symbols
τtime/s
ρdensity/(kg·m-3)
αheat transfer coefficient/(kJ·m-2·K-1)
σ ˙time rate of entropy production/(kJ·s-1·K-1)
Subscripts
CVcontrol volume
jlocations on the boundary of a system
iinlets
eexits
ffluid
bsolid surface
0environment

RIGHTS & PERMISSIONS

2014 Higher Education Press and Springer-Verlag Berlin Heidelberg
AI Summary AI Mindmap
PDF(159 KB)

Accesses

Citations

Detail

Sections
Recommended

/