scholarly journals Interactive graph dynamics for fuzzy autocatalytic set of fuzzy graph of type-3 for combustion process in a circulating fluidized bed boiler

2015 ◽  
Vol 11 (1) ◽  
Author(s):  
Hazwani Hashim ◽  
Sumarni Abu Bakar
Keyword(s):  
Fluidized Bed ◽  
Chemical Reactions ◽  
Transition Matrix ◽  
Circulating Fluidized Bed ◽  
Combustion Process ◽  
Fuzzy Graph ◽  
The Real ◽  
Real Process ◽  
Graph Dynamics ◽  
Type 3

Dynamical changes of chemical reactions which occurred during combustion process in Circulating Fluidized Bed boiler (CFB) has been modelled using adjacency matrix of Fuzzy Autocatalytic Set (FACS) of fuzzy graph type-3. Analysis of sequence of changes in the reactions at time t through Perron-Frobenious eigenvector (PFE) of the matrix in the Graph Dynamic Algorithm (GDA) shows that end-product of the combustion process in the CFB namely Water and Hydrogen is not really potrayed the real process.  Therefore, in this study, transition matrix of FACS is utilized to analyse the dynamical changes of the reactions and the GDA is modified and improvised and known as Interactive Graph Dynamics (IGD) is subsequently use to facilitate the analysis. The result shows that by using the transition matrix of FACS, the end-product of the combustion process in CFB is in accordance to the real process. Whilst the IGD is able to reduced computer running time as compared to the existing GDA. This paper describes the development of IGD and the analysis of sequence of changes of chemical reactions during combustion process in CFB by using transition matrix with the helped of MATLAB. 

scholarly journals Graph Dynamics of Fuzzy Autocatalytic Set of Fuzzy Graph Type-3 of a Clinical Waste Incineration Process

2014 ◽  
Vol 8 (4) ◽  
Author(s):  
Sumarni Abu Bakar ◽  
Tahir Ahmad ◽  
Sabariah Baharun
Keyword(s):  
Transition Matrix ◽  
Waste Incineration ◽  
Actual Process ◽  
Fuzzy Graph ◽  
Graph Type ◽  
Graph Dynamics ◽  
Incineration Process ◽  
Type 3 ◽  
Perron Vector

Fuzzy Autocatalytic Set of Fuzzy Graph Type-3 (FACS) has been successfully implemented in modeling clinical waste incineration process. Six important variables identified in the process are represented as nodes and the catalytic relationships are represented by fuzzy edges in the graph. However, in this paper, graph dynamics of FACS is further investigated using left Perron vector of its transition matrix of fuzzy graph of FACS. This paper will highlight two important variables in the incineration process with regards to the actual process.

scholarly journals Oxy-combustion of biomass in a circulating fluidized bed

2016 ◽  
Vol 37 (1) ◽  
pp. 17-30 ◽  
Author(s):  
Monika Kosowska-Golachowska ◽  
Agnieszka Kijo-Kleczkowska ◽  
Adam Luckos ◽  
Krzysztof Wolski ◽  
Tomasz Musiał
Keyword(s):  
Fluidized Bed ◽  
Ignition Temperature ◽  
Loss Rate ◽  
Circulating Fluidized Bed ◽  
Mass Loss Rate ◽  
Thermal Analyses ◽  
Combustion Process ◽  
Combustion Characteristics ◽  
Lower Maximum ◽  
Maximum Mass Loss

Abstract The objective of this study was to investigate combustion characteristics of biomass (willow, Salix viminalis) burnt in air and O2/CO2 mixtures in a circulating fluidized bed (CFB). Air and oxy-combustion characteristics of wooden biomass in CFB were supplemented by the thermogravimetric and differential thermal analyses (TGA/DTA). The results of conducted CFB and TGA tests show that the composition of the oxidizing atmosphere strongly influences the combustion process of biomass fuels. Replacing N2 in the combustion environment by CO2 caused slight delay (higher ignition temperature and lower maximum mass loss rate) in the combustion of wooden biomass. The combustion process in O2/CO2 mixtures at 30% and 40% O2 is faster and shorter than that at lower O2 concentrations.

Research on coal-water fuel combustion in a circulating fluidized bed / Badanie spalania zawiesinowych paliw węglowo-wodnych w cyrkulacyjnej warstwie fluidalnej

2012 ◽  
Vol 57 (1) ◽  
pp. 79-92
Author(s):  
Agnieszka Kijo-Kleczkowska
Keyword(s):  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Combustion Process ◽  
Fuel Combustion ◽  
Waste Materials ◽  
Inert Material ◽  
Process Conditions ◽  
Heat And Mass Exchange ◽  
Water Suspension ◽  
Power Stations

In the paper the problem of heavily-watered fuel combustion has been undertaken as the requirements of qualitative coals combusted in power stations have been growing. Coal mines that want to fulfill expectations of power engineers have been forced to extend and modernize the coal enrichment plants. This causes growing quantity of waste materials that arise during the process of wet coal enrichment containing smaller and smaller under-grains. In this situation the idea of combustion of transported waste materials, for example in a hydraulic way to the nearby power stations appears attractive because of a possible elimination of the necessary deep dehydration and drying as well as because of elimination of the finest coal fraction loss arising during discharging of silted water from coal wet cleaning plants. The paper presents experimental research results, analyzing the process of combustion of coal-water suspension depending on the process conditions. Combustion of coal-water suspensions in fluidized beds meets very well the difficult conditions, which should be obtained to use the examined fuel efficiently and ecologically. The suitable construction of the research stand enables recognition of the mechanism of coal-water suspension contact with the inert material, that affects the fluidized bed. The form of this contact determines conditions of heat and mass exchange, which influence the course of a combustion process. The specificity of coal-water fuel combustion in a fluidized bed changes mechanism and kinetics of the process.

scholarly journals Analysis and Discussion on Burning Low Calorific Value Fuel of Circulating Fluidized Bed Boiler

2021 ◽  
Vol 329 ◽  
pp. 01074
Author(s):  
Yi Yan
Keyword(s):  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
High Reliability ◽  
Combustion Process ◽  
Calorific Value ◽  
Utilization Rate ◽  
Energy Structure ◽  
Actual Process ◽  
Circulating Fluidized Bed Boiler ◽  
Power Stations

China's coal-dominated energy structure will not change in a short time. In order to implement the relevant national policies on energy conservation and emission reduction, it is a good response to adopt circulating fluidized bed boilers in coal-fired power stations. Circulating fluidized bed boiler adopts fluidized combustion, which has high reliability and high utilization rate because of its special combustion mode and particle recycling device. For the low calorific value inferior fuel which is difficult to burn in common boiler, CFB boiler also has certain adaptability and compatibility. In this background, this article with coal gangue as the representative of the inferior coal are discussed its application in the circulating fluidized bed boiler, the combustion process, boiler equipment and special fly ash produced by combustion is proposed that often appear in the three aspects of problems, and accordingly put forward the solution and optimization measures, provides reference for the actual process.

Evolution of the Structure and Mechanical Strength of a Coal Particle During Combustion in the Atmosphere of Air and the Mixture of Oxygen and Carbon Dioxide / Ewolucja Struktury Oraz Wytrzymałości Mechanicznej Ziarna Węgla Podczas Spalania W Atmosferze Powietrza Oraz Mieszaninie Tlenu I Dwutlenku Węgla

2013 ◽  
Vol 58 (3) ◽  
pp. 673-690
Author(s):  
Piotr Pełka ◽  
Grzegorz Golański ◽  
Paweł Wieczorek
Keyword(s):  
Carbon Dioxide ◽  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Sudden Change ◽  
Combustion Process ◽  
Ambient Air ◽  
Hard Coal ◽  
Atomic Force ◽  
Coal Particles ◽  
The Moment

Abstract The research was conducted on the basis of four different types of hard coal and one type of brown coal. There are typical coals commonly used as fuel in Polish CFB boilers. The combustion process was conducted at a temperature of 850°C and the atmosphere of ambient air as well as in the mixture of oxygen and carbon dioxide in different proportions. The research was carried out using specially prepared cubical coal particles with measurements of 15×15mm and also 10×10 mm. The change of the mechanical properties was analyzed based on three parameters, i.e. compression strength, Vickers hardness and fracture toughness. The analysis was supplemented by microscopic images of the surface of the particles using an atomic force microscope. The results obtained clearly indicated the mechanical changes of the coal during its combustion, particularly at the moment of ignition of the char. Moreover, the results correlate very well with the processes of coal comminution that have been described by other authors (Basu, 1999; Chirone et al., 1991) during combustion in the circulating fluidized bed and also explain the sudden change of susceptibility to erosion in the conditions with and without combustion. The measured values can be used as strength parameters in the modelling of the mass loss of coal particles in conditions of circulating fluidized bed combustor that are hard to describe.

Combustion of Refinery Residues in a CFB-Combustor: Measurement of Intermediate Species Using FTIR

2003 ◽  
Author(s):  
Christian Barczus ◽  
Bjo¨rn Henning ◽  
Viktor Scherer
Keyword(s):  
Combustion Chamber ◽  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Combustion Process ◽  
Thermal Capacity ◽  
Liquid Fuels ◽  
Gaseous Species ◽  
Nox Formation ◽  
Secondary Air ◽  
Fluidized Bed Combustor

Investigations have been performed to show the feasibility of burning refinery residues (calcined petroleum coke and liquid residues) in a circulating fluidized bed combustor. These experiments were done in a CFBC system with a thermal capacity of 100 kW. The unit has been equipped with an additional dosing system for liquid fuels including a newly developed fuel lance. The pollutant formation characteristics are determined using axial profile measurements at 19 different ports along the combustion chamber. To optimize the combustion process and to minimize gaseous pollutants, several operating parameters of the system are varied independently. These parameters are the primary to secondary air ratio, the global air to fuel ratio, the residence time in the primary zone, the overall temperature of the combustion chamber and the Ca/S ratio. Measurements of the flue gas components O2, CxHy, CO, CO2, H2, NOx, N2O, NH3 and SO2 are performed by standard gas analysing techniques. It is important to note that the system is equipped with a Fourier Transform Infrared Spectrometer (FTIR) to qualitatively and quantitatively determine selected gaseous species which are essential for the formation and consumption of N2O and other pollutants. The gas species measured by FTIR-Spectroscopy are CH4, C2H2, C2H4, C2H6, C3H6 and C3H8. Also the important precursors for the NOx-formation HCN and NH3 are examined with the FTIR-Spectrometer. The investigations demonstrate that (liquid) refinery residues can be burned successfully as a monofuel within the circulating fluidized bed combustor. The emissions of all pollutants detected are at a low level.

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