Analysis of Coal With Coal-Mule and Biomass Co-Combustion in Slurry Form/Analiza Współspalania Węgla Z Mułem Węglowym I Biomasą W Postaci Zawiesiny

2014 ◽  
Vol 59 (2) ◽  
pp. 347-366 ◽  
Author(s):  
Agnieszka Kijo-Kleczkowska
Keyword(s):  
Mathematical Model ◽  
Mass Loss ◽  
Fluidized Bed ◽  
Combustion Process ◽  
Environment Protection ◽  
Technical Application ◽  
Depth Analysis ◽  
Combustion Technology ◽  
The Mathematical Model

Abstract Combustion technology of coal-water fuels creates a number of new possibilities to organize the combustion process fulfilling contemporary requirements e. g in the environment protection. Therefore an in-depth analysis is necessary to examine the technical application of coal as energy fuel in the form of suspension. The paper undertakes the complex research of the coal with coal-mule and biomass co-combustion. The mathematical model enables the prognosis for change of the surface and the centre temperatures and a mass loss of the fuel during combustion in air and in the fluidized bed.

scholarly journals Analysis of cyclic combustion of the coal-water suspension

2011 ◽  
Vol 32 (1) ◽  
pp. 45-75 ◽  
Author(s):  
Agnieszka Kijo-Kleczkowska
Keyword(s):  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Combustion Process ◽  
Fuel Combustion ◽  
Technical Application ◽  
Water Suspension ◽  
Depth Analysis ◽  
Combustion Technology ◽  
Cyclic Changes ◽  
The Mathematical Model

Analysis of cyclic combustion of the coal-water suspension Combustion technology of the coal-water suspension creates a number of new possibilities to organize the combustion process fulfilling contemporary requirements, e.g. in the environment protection. Therefore the in-depth analysis is necessary to examine the technical application of coal as a fuel in the form of suspension. The research undertakes the complex investigations of the continuous coal-water suspension as well as cyclic combustion. The cyclic nature of fuel combustion results from the movement of the loose material in the flow contour of the circulating fluidized bed (CFB): combustion chamber, cyclone and downcomer. The experimental results proved that the cyclic change of oxygen concentration around fuel, led to the vital change of both combustion mechanisms and combustion kinetics. The mathematical model of the process of fuel combustion has been presented. Its original concept is based on the allowance for cyclic changes of concentrations of oxygen around the fuel. It enables the prognosis for change of the surface and the centre temperatures as well as mass loss of the fuel during combustion in air, in the fluidized bed and during the cyclic combustion.

Influence of Imperfections in the Working Media on Diesel Engine Indicator Process: Part 2 — Results

1998 ◽  
Author(s):  
Stanislav N. Danov ◽  
Ashwani K. Gupta
Keyword(s):  
Mathematical Model ◽  
Diesel Engine ◽  
High Pressures ◽  
Combustion Process ◽  
Ideal Gas ◽  
Working Medium ◽  
High Pressures And Temperatures ◽  
Specific Heat Capacities ◽  
Working Media ◽  
The Mathematical Model

Abstract In the companion Part 1 of this two-part series paper several improvements to the mathematical model of the energy conversion processes, taking place in a diesel engine cylinder, have been proposed. Analytical mathematical dependencies between thermal parameters (pressure, temperature, volume) and caloric parameters (internal energy, enthalpy, specific heat capacities) have been obtained. These equations have been used to provide an improved mathematical model of diesel engine indicator process. The model is based on the first law of thermodynamics, by taking into account imperfections in the working media which appear when working under high pressures and temperatures. The numerical solution of the simultaneous differential equations is obtained by Runge-Kutta type method. The results show that there are significant differences between the values calculated by equations for ideal gas and real gas under conditions of high pressures and temperatures. These equations are then used to solve the desired practical problem in two different two-stroke turbo-charged engines (8DKRN 74/160 and Sulzer-RLB66). The numerical experiments show that if the pressure is above 8 to 9 MPa, the working medium imperfections must be taken into consideration. The mathematical model presented here can also be used to model combustion process of other thermal engines, such as advanced gas turbine engines and rockets.

scholarly journals Wheat Germ Drying with Different Time-Temperature Combinations in a Fluidized Bed Dryer

Processes ◽  
2018 ◽  
Vol 6 (12) ◽  
pp. 245 ◽  
Author(s):  
Der-Sheng Chan ◽  
Meng-I Kuo
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Fluidized Bed ◽  
Wheat Germ ◽  
Dynamic Equilibrium ◽  
Cooling Stage ◽  
Fluidized Bed Dryer ◽  
Drying Condition ◽  
Drying Conditions ◽  
The Mathematical Model

The development of an effective drying performance of the fluidized bed dryer (FBD) is crucial to reduce drying costs. The objective of this study was to investigate the drying performance of wheat germ (WG) with different time-temperature combinations in the FBD. The WG was dried at different set temperatures of 80, 100 and 120 °C. The moisture content (MC) and water activity (WA) of WG were measured. A mathematical model was proposed to develop an optimal drying condition. The changes in the MC of WG during drying in the FBD could be divided into the decreased period, the dynamic equilibrium period and the increased period. The product temperature of 45 °C and WA of 0.3 of WG drying could be attained by different time-temperature combinations. The mathematical model, which was developed in conjunction with different time-temperature combinations, could predict the dehydration time and the condensation time of WG for optimization the drying conditions. The WG dehydration at the heating stage and the WG condensation at the cooling stage could also be evaluated by the dehydration flux and the condensation flux, respectively. The optimal drying performance of WG exists in a compromise between promoting dehydration and reducing condensation. Information obtained from the analysis of dehydration flux and condensation flux with experimental data and simulation gave the guidelines for performing an effective drying of WG in the FBD.

Computations of Three-Dimensional Gas-Turbine Combustion Chamber Flows

1979 ◽  
Vol 101 (3) ◽  
pp. 326-336 ◽  
Author(s):  
M. A. Serag-Eldin ◽  
D. B. Spalding
Keyword(s):  
Mathematical Model ◽  
Turbulent Flows ◽  
Combustion Process ◽  
Three Dimensional ◽  
Solution Algorithm ◽  
Physical Models ◽  
Turbulence Energy ◽  
Experimental Conditions ◽  
Diffusion Controlled ◽  
The Mathematical Model

The paper presents a mathematical model for three-dimensional, swirling, recirculating, turbulent flows inside can combustors. The present model is restricted to single-phase, diffusion-controlled combustion, with negligible radiation heat-transfer; however, the introduction of other available physical models can remove these restrictions. The mathematical model comprises differential equations for: continuity, momentum, stagnation enthalpy, concentration, turbulence energy, its dissipation rate, and the mean square of concentration fluctuations. The simultaneous solution of these equations by means of a finite-difference solution algorithm yields the values of the variables at all internal grid nodes. The prediction procedure, composed of the mathematical model and its solution algorithm, is applied to predict the fields of variables within a representative can combustor; the results are compared with corresponding measurements. The predicted results give the same trends as the measured ones, but the quantitative agreement is not always acceptable; this is attributed to the combustion process not being truly diffusion-controlled for the experimental conditions investigated.

Optimization of the Algebraic Model of Constructive Logic

10.12737/2691 ◽  
2014 ◽  
Vol 8 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Хромушин ◽  
Oleg Khromushin ◽  
Хромушин ◽  
Viktor Khromushin ◽  
Дзасохов ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Oxygen Therapy ◽  
Model Identification ◽  
Algebraic Model ◽  
Constructive Logic ◽  
Top Down ◽  
Number Of Components ◽  
Depth Analysis ◽  
The Mathematical Model ◽  
Oncological Pathology

The authors proposed and evaluated options of optimization of the algebraic model of constructive logic, designed to construct multichannel non-linear mathematical model often used in Russia in the in-depth analysis in medicine and biology. In the basis of optimization of this model are procedures for finding duplicate cases (rows base), relevant to the achievement of goals, and excluding those resulting components that are duplicated other cases the resulting components. Procedures for reviewing the results of the components of a top-down or bottom-up and comparing the numbers corresponding to achievement of objectives are the basis of optimization. If all the numbers viewing the resulting component will be present in other watched the resulting components, then it is removed as redundant. As a result of identifying and eliminating redundant coatings target lines are reducing the number of resulting parts. Reduction of number of resulting components is achieved by identifying and eliminating redundant coatings target lines. The results of two variants of optimization of mathematical model are shown on the example of the mathematical model identification features of the method of oxygen therapy in the treatment of oncological pathology. The authors suggested the possibility of practical use of various optimization algorithms to choose model with a minimal number of components of the resulting/

scholarly journals Mathematical model of unsteady gas to solid particles heat transfer in fluidized bed

2009 ◽  
Vol 13 (1) ◽  
pp. 55-68 ◽  
Author(s):  
Mladen Stojiljkovic ◽  
Branislav Stojanovic ◽  
Jelena Janevski ◽  
Gradimir Ilic
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Computer Program ◽  
Fluidized Bed ◽  
Particle Temperature ◽  
Prediction Method ◽  
Solid Particles ◽  
Gas Temperature ◽  
One Dimensional ◽  
The Mathematical Model

The mathematical model of unsteady one-dimensional gas to particles heat transfer for non-isothermal fluidized bed with periodic heating of solid particles has been described. The method of numerical solution of governing differential equations, the algorithm and the computer program, have been presented. By using mathematical model and computer program, the temperature profiles for interstitial gas, gas in bubbles, and solid particles along the height of fluidized bed in function of time, have been determined. The results obtained on the basis of prediction method are compared to the experimental results of the authors; the satisfactory agreement has been found for interstitial gas temperature and solid particle temperature. On the basis of this comparison, the mathematical model has been verified.

The Application of SunyPCC800 in CFB Boilers

2012 ◽  
Vol 535-537 ◽  
pp. 779-782
Author(s):  
Yu Ping Yang ◽  
Yun Feng Xu
Keyword(s):  
Fluidized Bed ◽  
High Efficiency ◽  
Circulating Fluidized Bed ◽  
Air Flow ◽  
Combustion Process ◽  
Control Effect ◽  
Coal Quality ◽  
Loop Control ◽  
Combustion Technology ◽  
Secondary Air

The combustion technology of Circulating Fluidized Bed Boilers is a Cleaning and high efficent of Coal Powder Combustion technology. Traditional control methods can hardly get ideal control effect. To Realize datas reading and writing by self_control software throgh DCS, when coal quality, loading altered, realized automatic closed-loop control of combustion process of circulating fluidized bed, to implement primary air flow, secondary air flow and air-induced automatic cordinated control and reached cleaning of coal quality and combustion high efficiency.

scholarly journals DEVELOPMENT OF AN AUTOMATED DIAGNOSTICS AND CONTROL SYSTEM FOR BIOGAS COMBUSTION PROCESSES

2017 ◽  
Vol 7 (4) ◽  
pp. 15-19
Author(s):  
Oxana Zhirnova
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Combustion Process ◽  
Research Process ◽  
Energy Performance ◽  
Pilot Studies ◽  
Complex Process ◽  
Combustion Processes ◽  
And Control ◽  
The Mathematical Model

The article shows the ecological and economic efficiency of biogas. Depending on the complexity of the tasks, the mathematical model could describe the research process with varying degrees of accuracy. Thus, numerical simulation should be combined with experimental research to compare and assess the validity of the model. Below is presented, a mathematical model of combustion of biogas. Then, based on the results of pilot studies to validate the mathematical model, a numerical simulation of the combustion of biogas. Process for the combustion of biogas is a complex process of their heterogeneous and homogenous combustion. The model of combustion process of extreme management not good can improve energy performance by maintaining the optimum cop value. Proved by simulation model of extreme management efficiency in changing signal assignments, the maintenance efficiency of the boiler is on a level with the specified accuracy.

scholarly journals The Evolutions in Time of Probability Density Functions of Polydispersed Fuel Spray—The Continuous Mathematical Model

2021 ◽  
Vol 11 (20) ◽  
pp. 9739
Author(s):  
Shlomo Hareli ◽  
Ophir Nave ◽  
Vladimir Gol’dshtein
Keyword(s):  
Mathematical Model ◽  
Combustion Process ◽  
Computation Time ◽  
Fuel Spray ◽  
Ignition Process ◽  
Experimental Distribution ◽  
Elegant Method ◽  
Short Period ◽  
The Right ◽  
The Mathematical Model

The dynamics of the particle size distribution (PSD) of polydispersed fuel spray is important in the evaluation of the combustion process. A better understanding of the dynamics can provide a tool for selecting a PSD that will more effectively meet the needs of the system. In this paper, we present an efficient and elegant method for evaluating the dynamics of the PSD. New insights into the behaviour of polydispersed fuel spray were obtained. A simplified theoretical model was applied to the experimental data and a known approximation of the polydispersed fuel spray. This model can be applied to any distribution, not necessarily an experimental distribution or approximation, and involves a time-dependent function of the PSD. Such simplified models are particularly helpful in qualitatively understanding the effects of various sub-processes. Our main results show that during the self-ignition process, the radii of the droplets decreased as expected, and the number of smaller droplets increased in inverse proportion to the radius. An important novel result (visualised by graphs) demonstrates that the mean radius of the droplets initially increases for a relatively short period of time, which is followed by the expected decrease. Our modified algorithm is superior to the well-known `parcel’ approach because it is much more compact; it permits analytical study because the right-hand sides of the mathematical model are smooth, and thus eliminates the need for a numerical algorithm to transition from one parcel to another. Moreover, the method can provide droplet radii resolution dynamics because it can use step functions that accurately describe the evolution of the radii of the droplets. The method explained herein can be applied to any approximation of the PSD, and involves a comparatively negligible computation time.

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