Thermal simulation of superheaters taking into account the processes occurring on the side of the steam and flue gas

Abstract Superheater model was used to analyzing the impact of ash deposits on the outer tube surfaces and scales formed on the inner tube surfaces on the heat flow rate transferred from the flue gas to the steam. The influence of uneven heating of parallel superheater tubes on the flow and temperature maldistribution was also examined. Excessive heating of some tubes reduces the mass flow rate of the steam flowing through these tubes. It may result in overheating of the tube material. Excessive local tube heating by a higher temperature flue gas, in combination with lower steam mass flow rate through each tube, can contribute to the overheating of the tube material. Ash fouling causes a significant decrease in heat flux absorbed by the steam and lowering the temperature of the tube metal. Scale depositions on the inner surface of the tube cause a big increase in wall temperature of superheater tubes despite a decrease in the heat flux transferred from the flue gas to the steam.

[1]  Majid Amidpour,et al.  Applying different optimization approaches to achieve optimal configuration of a dual pressure heat , 2012 .

[2]  A. Fakheri.  Heat Transfer in Pipe Flow , 2008 .

[3]  R. Bahrampoury,et al.  Optimization of fire tube heat recovery steam generators for cogeneration plants through genetic algorithm , 2010 .

[4]  M. Pronobis,et al.  The rate of corrosive wear in superheaters of boilers for supercritical parameters of steam , 2012 .

[5]  David N. French,et al.  Metallurgical Failures in Fossil Fired Boilers , 1983 .

[6]  D. Taler,et al.  Simplified Analysis of Radiation Heat Exchange in Boiler Superheaters , 2009 .

[7]  Judha Purbolaksono,et al.  A new method for estimating heat flux in superheater and reheater tubes , 2009 .

[8]  D. P. Sekulic,et al.  Fundamentals of Heat Exchanger Design , 2003 .

[9]  Lijun Xu,et al.  Thermal load deviation model for superheater and reheater of a utility boiler , 2000 .

[10]  Masoud Rahimi,et al.  CFD modeling of a boiler’s tubes rupture , 2006 .

[11]  Panagiotis Grammelis,et al.  Decoupled CFD simulation of furnace and heat exchangers in a lignite utility boiler , 2014 .

[12]  Judha Purbolaksono,et al.  Failure investigation on deformed superheater tubes , 2009 .

[13]  Hartmut Spliethoff,et al.  Coupled simulation of a tangentially hard coal fired 700 °C boiler , 2014 .

[14]  G. L. Shires,et al.  Process Heat Transfer , 1994 .

[15]  G. H. Babcock,et al.  Steam / its generation and use , 1972 .

[16]  J. Oakey,et al.  Fireside corrosion of superheaters: Effects of air and oxy-firing of coal and biomass , 2012 .

[17]  M. Mancini,et al.  On predicting the ash behaviour using Computational Fluid Dynamics , 2013 .

[18]  H. Spliethoff,et al.  Evaluation, comparison and validation of deposition criteria for numerical simulation of slagging , 2012 .

[19]  G. Manadili,et al.  Replace implicit equations with signomial functions , 1997 .

[20]  Dawid Taler,et al.  Identification of thermal boundary conditions in heat exchangers of fluidized bed boilers , 2013 .

[21]  P. J. Stopford,et al.  Coupled fluid dynamics and whole plant simulation of coal combustion in a tangentially-fired boiler , 2010 .

[22]  Harun Bilirgen,et al.  Slagging in PC boilers and developing mitigation strategies , 2014 .

[23]  Honghi Tran,et al.  Numerical modeling of fine particle and deposit formation in a recovery boiler , 2014 .

[24]  N. S. Harding,et al.  Ash deposition impacts in the power industry , 2007 .

[25]  Nikolaos Samaras,et al.  Simulation of a coal-fired power plant using mathematical programming algorithms in order to optimize its efficiency , 2012 .

[26]  Judha Purbolaksono,et al.  Failure analysis on a primary superheater tube of a power plant , 2010 .

[27]  Sang Yong Lee,et al.  Optimization of heat recovery steam generator through exergy analysis for combined cycle gas turbine power plants , 2008 .

[28]  D. F. Peterson,et al.  Standard Methods Of Hydraulic Design For Power Boilers , 1988 .