PAHs Emission Characteristics and Assessment from the Coal Combustion Process in the Large Capacity Power Plant Boilers

2013 ◽  
Vol 726-731 ◽  
pp. 1908-1916 ◽  
Author(s):  
Xue Feng Yin ◽  
Wen Ting Yang ◽  
Hui Min Xue
Keyword(s):  
Power Plant ◽  
Coal Combustion ◽  
Electrostatic Precipitator ◽  
Combustion Process ◽  
Ambient Air ◽  
Emission Characteristic ◽  
Air Pollution Control ◽  
Environment Impact ◽  
Emission Data ◽  
Large Capacity

Many studies have demonstrated an association between exposure to ambient Polycyclic Aromatic Hydrocarbons (PAHs) and some serious diseases, such as cancer, malformation and mutation. PAHs is thought as a carcinogenic and mutagenic compound to human health. Coal-fired power plant industry plays an important role in the observed PAHs emission process. However, the PAHs emission characteristic and environment impact in coal-fired power plant is still not fully clarified. In this study, the PAHs distribution characteristic of the flue gas and fly ash emitted from electrostatic precipitator in two coal-fired power plant boilers with the steam capacity 1000t/h and 2000t/h have been studied in China based on USEPA method 0023(sampling part). PAHs concentrations and PAHs emission factors were determined. And the correlation between PAHs emission and the steam capacity of the power plant boiler was discussed. In addition, the PAHs removal effects of air pollution control devices were also included. According to the measured PAHs emission data and the report of China statistical year book, the PAHs emission assessment from the coal combustion process in the large capacity co-fired power plant boilers have been done. Though the PAHs emission value in the large capacity power plant were present within recommended emission limits of energy production, the problem of PAHs emission in large capacity coal-fired power plant shouldnt be ignored due to the huge amounts and long-range transport in soil, water and ambient air.

Characterization of Catalyzed Devitrification in Quenched Fly Ash Melts

1984 ◽  
Vol 43 ◽  
Author(s):  
Subhash H. Risbud
Keyword(s):  
Fly Ash ◽  
Coal Combustion ◽  
Ceramic Body ◽  
Combustion Process ◽  
Bottom Ash ◽  
Waste Utilization ◽  
Raw Material ◽  
Friable Material ◽  
Air Pollution Control ◽  
Silica Alumina

Coal combustion produces enormous quantities of residual ash often called bottom ash or fly ash. The fly ash component contains lightweight cenospheres giving the ash a fluffy character. Fly ash is captured in the coal combustion process by air pollution control devices as the gases exit the stack. Fly ash compositions are usually highly siliceous consisting mainly of the oxides of silica, alumina, calcia, and iron oxides; minor constituents such as MgO, alkali oxides, TiO2 etc. are also almost invariably present in quantities of ≈0.5 to 3 wt%. Two important aspects of crystallization of fly ash melts and glasses relate to the prevention of boiler slagging [1] and, from a waste utilization point of view, to the development of new products using fly ash as a raw material[2–4]. Ash devitrification on cooling of the melt results in friable material that does not stick to boiler walls as easily as glassy slag [5]. From another standpoint, crystallization of glassy ash slag to a fine grained equiaxed microstructure is considered a desirable glass-ceramic body for thermomechanical reasons [6].

scholarly journals Combustion Optimization for Coal Fired Power Plant Boilers Based on Improved Distributed ELM and Distributed PSO

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1036 ◽  
Author(s):  
Xinying Xu ◽  
Qi Chen ◽  
Mifeng Ren ◽  
Lan Cheng ◽  
Jun Xie
Keyword(s):  
Power Plant ◽  
Combustion Process ◽  
Optimization Method ◽  
Combustion Efficiency ◽  
Pollutant Emissions ◽  
Combustion Model ◽  
Nox Emissions ◽  
Coupling Characteristics ◽  
Learning Machine ◽  
Combustion Optimization

Increasing the combustion efficiency of power plant boilers and reducing pollutant emissions are important for energy conservation and environmental protection. The power plant boiler combustion process is a complex multi-input/multi-output system, with a high degree of nonlinearity and strong coupling characteristics. It is necessary to optimize the boiler combustion model by means of artificial intelligence methods. However, the traditional intelligent algorithms cannot deal effectively with the massive and high dimensional power station data. In this paper, a distributed combustion optimization method for boilers is proposed. The MapReduce programming framework is used to parallelize the proposed algorithm model and improve its ability to deal with big data. An improved distributed extreme learning machine is used to establish the combustion system model aiming at boiler combustion efficiency and NOx emission. The distributed particle swarm optimization algorithm based on MapReduce is used to optimize the input parameters of boiler combustion model, and weighted coefficient method is used to solve the multi-objective optimization problem (boiler combustion efficiency and NOx emissions). According to the experimental analysis, the results show that the method can optimize the boiler combustion efficiency and NOx emissions by combining different weight coefficients as needed.

scholarly journals Simulation of Thermal Effects on the Flow Field in a Pilot-Scale Kiln

2021 ◽  
Author(s):  
I. A. Sofia Larsson ◽  
Anna-Lena Ljung ◽  
B. Daniel Marjavaara
Keyword(s):  
Flow Field ◽  
Coal Combustion ◽  
Thermal Effects ◽  
Iron Ore ◽  
Combustion Process ◽  
Pilot Scale ◽  
Mixing Properties ◽  
Process Gas ◽  
Mixing Rates ◽  
Computational Fluid Dynamics Cfd

AbstractThe flow field and coal combustion process in a pilot-scale iron ore pelletizing kiln is simulated using a computational fluid dynamics (CFD) model. The objective of the work is to investigate how the thermal effects from the flame affect the flow field. As expected, the combustion process with the resulting temperature rise and volume expansion leads to an increase of the velocity in the kiln. Apart from that, the overall flow field looks similar regardless of whether combustion is present or not. The flow field though affects the combustion process by controlling the mixing rates of fuel and air, governing the flame propagation. This shows the importance of correctly predicting the flow field in this type of kiln, with a large amount of process gas circulating, in order to optimize the combustion process. The results also justify the use of down-scaled, geometrically similar, water models to investigate kiln aerodynamics in general and mixing properties in particular. Even if the heat release from the flame is neglected, valuable conclusions regarding the flow field can still be drawn.

scholarly journals Effects of Baffles on Flow Distribution in an Electrostatic Precipitator (ESP) of a Coal Based Power Plant

2015 ◽  
Vol 105 ◽  
pp. 529-536 ◽  
Author(s):  
A.S.M. Sayem ◽  
M.M.K. Khan ◽  
M.G. Rasul ◽  
M.T.O. Amanullah ◽  
N.M.S. Hassan
Keyword(s):  
Power Plant ◽  
Electrostatic Precipitator ◽  
Flow Distribution

Coeffect of Air Pollution Control Devices on Trace Element Emissions in an Ultralow Emission Coal-Fired Power Plant

2018 ◽  
Vol 33 (1) ◽  
pp. 248-256 ◽  
Author(s):  
Jiawei Wang ◽  
Yongsheng Zhang ◽  
Zhao Liu ◽  
Yongzheng Gu ◽  
Pauline Norris ◽  
...  
Keyword(s):  
Air Pollution ◽  
Power Plant ◽  
Trace Element ◽  
Pollution Control ◽  
Air Pollution Control ◽  
Control Devices ◽  
Air Pollution Control Devices

Innovative Passive Flame Ameliorator for a Diffusion Flame Burner Using Chevrons

2015 ◽  
Vol 787 ◽  
pp. 732-735
Author(s):  
A. Alaguraja ◽  
S. Balaji ◽  
Inti Sandeep ◽  
M. Karthikeyan ◽  
S. Soma Sundaram
Keyword(s):  
Diffusion Flame ◽  
Acoustic Noise ◽  
Combustion Process ◽  
Ambient Air ◽  
Premixed Flame ◽  
Experimental Investigations ◽  
Exhaust Gas ◽  
Novel Approach ◽  
Flame Burner ◽  
Safety Considerations

Diffusion flame burners are mainly used in industries over premixed flame burners for safety considerations. But the combustion process in a diffusion flame is not complete and the flame is usually in bright yellow in colour in contrast to the premixed flame which gives a bluish flame. To improve the combustion process in a diffusion flame burner a novel approach, using chevrons has been carried out. The chevrons are found to reduce the aero-acoustic noise in the exhaust jets of aircraft engines by allowing better mixing of the exhaust gas with the ambient air. The similar concept is used here where the tips of the burners are cut in the form of chevrons. Experimental investigations are carried out on burners with three and four chevrons in addition to a standard burner using LPG as the fuel. The results indicate that with the introduction of chevrons the diffusion flame becomes more compact. The premixed region, in the diffusion flame, where the air and fuel is mixed well is found to increase by nearly 100 % with the usage of chevrons, indicating better mixing of fuel and air. The results also indicate that increasing the number of chevrons from three to four does not show much variation. Further experiments are to be carried out to determine the improved fuel consumption with the usage of chevrons.

Research on the Primary Frequency Regulation of the Large Capacity Thermal Power Units

2014 ◽  
Vol 608-609 ◽  
pp. 915-919 ◽  
Author(s):  
Hong Xia Wu
Keyword(s):  
Power Plant ◽  
Control Method ◽  
Power Grid ◽  
Thermal Power ◽  
Frequency Regulation ◽  
Load Curve ◽  
Large Capacity ◽  
Continuous Increase ◽  
Important Index ◽  
Primary Frequency

Frequency is an important index of power quality, primary frequency regulation is of great significance for maintaining the grid frequency. In recent years, with the expansion of the power grid capacity and the continuous increase of the generator capacity, the large capacity units play a role is becoming more and more important in the primary frequency regulation of power grid. This paper takes ultra supercritical coal-fired units (1000MW) of a power plant of Hubei for example, primary frequency regulation control method, requency offset load curve and so on were studied through relevant test.

A Hybrid Technique for the Performance Optimization in the Combustion Process of a Power Plant Boiler: An Efficient ANNSSA Technique

2021 ◽  
Author(s):  
P. V. Narendra Kumar ◽  
Ch. Chengaiah ◽  
P. Rajesh ◽  
Francis H. Shajin
Keyword(s):  
Power Plant ◽  
Performance Optimization ◽  
Combustion Process ◽  
Combustion Efficiency ◽  
Flue Gases ◽  
Unburned Carbon ◽  
Hybrid Technique ◽  
Power Plant Boiler ◽  
Artificial Neural Network Ann ◽  
Plant Boiler

In this paper presents a hybrid method for optimization process of combustion in power plant boiler. ANSSA scheme will be joint implementation of Artificial Neural Network (ANN) as well as Salp Swarm Optimization Algorithm (SSA) known ANNSSA. Here, ANN training process will be enhanced by using the SSA calculating. The optimization of economic parameters reduces excess air level and performs combustion efficiency at boiler system. Due to the operation of service boiler, oxygen content of flue gases is one of the significant factors which influence the efficiency of boiler, and influence each other to other thermal parameters of economic like temperature of flue gases combustion, unburned carbon at fly ash slag and consumption of coal power supply. The combustion performance denotes a saving at operating costs of boiler. ANNSSA method evolved for process of combustion to enhance the implementation and efficiency of the power plant boiler. At that time, ANNSSA technique is implemented at MATLAB/Simulink work platform as well as implementation is evaluated using existing techniques.

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