The dynamic plant simulation of CO2-recovery type pulverized-coal fired power plants applied oxygen/recycled flue gas combustion

1999 ◽  
pp. 593-597 ◽  
Author(s):  
T. Yamada ◽  
T. Kiga ◽  
N. Fujita ◽  
T. Inoue ◽  
K. Arai ◽  
...  
Keyword(s):  
Flue Gas ◽  
Power Plants ◽  
Pulverized Coal ◽  
Gas Combustion ◽  
Dynamic Plant ◽  
Co2 Recovery ◽  
Plant Simulation

Characteristics of pulverized-coal combustion in the system of oxygen/recycled flue gas combustion

1997 ◽  
Vol 38 ◽  
pp. S129-S134 ◽  
Author(s):  
T Kiga ◽  
S Takano ◽  
N Kimura ◽  
K Omata ◽  
M Okawa ◽  
...  
Keyword(s):  
Flue Gas ◽  
Coal Combustion ◽  
Pulverized Coal ◽  
Pulverized Coal Combustion ◽  
Gas Combustion

Reburning of Cattle Manure-Based Biomass With Coals in a Small Scale Boiler Burner Facility for NOx and Hg Reduction

2011 ◽  
Author(s):  
Hyukjin Oh ◽  
Kalyan Annamalai ◽  
John Sweeten
Keyword(s):  
Flue Gas ◽  
Power Plants ◽  
Molecular Nitrogen ◽  
Pulverized Coal ◽  
Cattle Manure ◽  
Solid Fuels ◽  
Small Scale ◽  
Fixed Carbon ◽  
Boiler Burner ◽  
Conversion Technologies

Reburning of cattle manure-based biomass (CB) with coals is performed to develop environmentally friendly thermo-chemical energy conversion technologies for NOx reductions and Hg captures and removals from existing pulverized coal-fired power plants. A small-scale (30 kWth) down-fired boiler burner facility has been used for burning most types of pulverized solid fuels including coal and biomass. Blends of CB and coals are used as reburn fuels. It has hypothesized that a major fraction of the fuel-N in the CB is released in the form of NH3 or urea. In the reburn process, therefore, it is believed that NOx produced by coal is reduced to molecular nitrogen by NH3 released from the pyrolysis of CB under slightly fuel-rich conditions. The CB also contains larger amounts of chlorine (Cl) than most types of coals. Hence gaseous mercury (Hg) in the flue gas is oxidized by large amounts of Cl species mainly from the CB combustion. Consequently, the results indicate that the CB can serve as a very effective fuel supplementing coals on NOx reductions and Hg captures and removals in pulverized coal-fired boilers. It was also found that the auto-gasification occurred during the pyrolysis due to the oxygen available in the fuel mainly helped for burning fixed carbon.

Design and Computational Validation of In-Line Bare Tube Economizer for a 210 MW Pulverized Coal Fired Boiler

2013 ◽  
Author(s):  
P. R. Dhamangaonkar ◽  
Abhishek Deshmukh ◽  
Santosh Pansare ◽  
M. R. Nandgaonkar
Keyword(s):  
Fly Ash ◽  
Flue Gas ◽  
Power Plants ◽  
Gas Flow ◽  
Tube Bundle ◽  
Thermal Power ◽  
Pulverized Coal ◽  
Root Cause ◽  
Economizer Tube ◽  
Bare Tube

One of the pulverized coal fired thermal power plants in India intended to find the root cause of frequent boiler tube failures in three 210 MW units. Operation & Maintenance history and feedback from plant O&M team revealed that economizer tube failure was a frequent cause of forced outage. The plant under study used CFS (continuous fin surface) economizer with staggered tube arrangement in the 210 MW units. CFS staggered tube economizers originally appealed to many plant designers because the tortuous path created for the flue gas, enhanced heat absorption and the fins could capture heat and transfer it to the tubing. This made the CFS economizer less costly and easy for installation in a relatively small space. There is increasing use of lower quality high ash coals over the past few decades. Due to this fact an advantage of the CFS economizer design became a disadvantage. The narrow spacing in the tubes proved more susceptible to plugging and fly ash erosion. Literature study and the root cause analysis suggested that CFS staggered arrangement of economizer could be one of the prominent reason of failure of economizer tube bundle due to fly ash erosion. Flue gas flow simulation also highlighted that there is increase in velocity of flue gases across the economizer. A bare tube in-line configuration in place of existing CFS economizer was an alternative. To recommend an alternate economizer as solution, the merits of an in-line bare tube economizer were studied. Bare tubes arranged in-line are most conservative in hostile environments with high ash content, are least likely to plug, and have the lowest gas-side resistance per unit of heat transfer. A bare tube in-line economizer that can replace the existing finned tube economizer in the available space while meeting the existing design & performance parameters is recommended. An attempt was made to model & analyze the new economizer using computational fluid dynamics (CFD) tools in order to get firsthand experience and validate the results obtained using manual calculations. With limited computational resources and not so fine meshing, the performed CFD model analysis showed the expected trend but did not completely match the results.

Could biomass-fueled boilers be operated at higher steam temperatures? Part 3: Initial analysis of costs and benefits

TAPPI Journal ◽  
2014 ◽  
Vol 13 (8) ◽  
pp. 65-78 ◽  
Author(s):  
W.B.A. (SANDY) SHARP ◽  
W.J. JIM FREDERICK ◽  
JAMES R. KEISER ◽  
DOUGLAS L. SINGBEIL
Keyword(s):  
Flue Gas ◽  
Power Plants ◽  
Superheated Steam ◽  
Black Liquor ◽  
Simulation Software ◽  
Operating Conditions ◽  
Costs And Benefits ◽  
Steam Generation ◽  
Fireside Corrosion ◽  
Corrosion Resistant

The efficiencies of biomass-fueled power plants are much lower than those of coal-fueled plants because they restrict their exit steam temperatures to inhibit fireside corrosion of superheater tubes. However, restricting the temperature of a given mass of steam produced by a biomass boiler decreases the amount of power that can be generated from this steam in the turbine generator. This paper examines the relationship between the temperature of superheated steam produced by a boiler and the quantity of power that it can generate. The thermodynamic basis for this relationship is presented, and the value of the additional power that could be generated by operating with higher superheated steam temperatures is estimated. Calculations are presented for five plants that produce both steam and power. Two are powered by black liquor recovery boilers and three by wood-fired boilers. Steam generation parameters for these plants were supplied by industrial partners. Calculations using thermodynamics-based plant simulation software show that the value of the increased power that could be generated in these units by increasing superheated steam temperatures 100°C above current operating conditions ranges between US$2,410,000 and US$11,180,000 per year. The costs and benefits of achieving higher superheated steam conditions in an individual boiler depend on local plant conditions and the price of power. However, the magnitude of the increased power that can be generated by increasing superheated steam temperatures is so great that it appears to justify the cost of corrosion-mitigation methods such as installing corrosion-resistant materials costing far more than current superheater alloys; redesigning biomassfueled boilers to remove the superheater from the flue gas path; or adding chemicals to remove corrosive constituents from the flue gas. The most economic pathways to higher steam temperatures will very likely involve combinations of these methods. Particularly attractive approaches include installing more corrosion-resistant alloys in the hottest superheater locations, and relocating the superheater from the flue gas path to an externally-fired location or to the loop seal of a circulating fluidized bed boiler.

Life Cycle Analysis: Sub-Critical Pulverized Coal (SubPC) Power Plants

2018 ◽  
Author(s):  
Timothy J Skone ◽  
Greg Schivley ◽  
Matthew Jamieson ◽  
Joe Marriott ◽  
Greg Cooney ◽  
...  
Keyword(s):  
Life Cycle ◽  
Life Cycle Analysis ◽  
Power Plants ◽  
Pulverized Coal
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