scholarly journals Operational Flexibility of a CFB Furnace during Fast Load Change—Experimental Measurements and Dynamic Model

2020 ◽  
Vol 10 (17) ◽  
pp. 5972
Author(s):  
Jens Peters ◽  
Falah Alobaid ◽  
Bernd Epple
Keyword(s):  
Experimental Data ◽  
Process Simulation ◽  
Circulating Fluidized Bed ◽  
Test Point ◽  
Hydrodynamic Condition ◽  
Operational Flexibility ◽  
Load Following ◽  
Load Change ◽  
Key Characteristics ◽  
Bed Material

The share of power from fluctuating renewable energies such as wind and solar is increasing due to the ongoing climate change. It is therefore essential to use technologies that can compensate for these fluctuations. Experiments at 1 MWth scale were carried out to evaluate the operational flexibility of a circulating fluidized bed (CFB) combustor during transient operation from 60% to 100% load. A typical load following sequence for fluctuating electricity generation/demand was reproduced experimentally by performing 4 load changes. The hydrodynamic condition after a load change depends on if the load change was in positive or negative direction due to the heat stored in the refractory/bed material at high loads and released when the load decreases. A 1.5D-process simulation model was created in the software APROS (Advanced Process Simulation) with the target of showing the specific characteristics of a CFB furnace during load following operation. The model was tuned with experimental data of a steady-state test point and validated with the load cycling tests. The simulation results show the key characteristics of CFB combustion with reasonable accuracy. Detailed experimental data is presented and a core-annulus approach for the modeling of the CFB furnace is used.

An Experiment on Solid Circulation Characteristics of a Dual Circulating fluidized Bed Based on Biomaterial Properties and Mechanics Properties

2012 ◽  
Vol 600 ◽  
pp. 261-264
Author(s):  
Teng Ge Mi ◽  
Ying Zhao ◽  
Chang Qing Dong ◽  
Wei Liang Cheng
Keyword(s):  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Circulation Rate ◽  
Gas Velocity ◽  
Solid Circulation Rate ◽  
Dual Fluidized Bed ◽  
Bed Material ◽  
Circulation Characteristics

In this paper, a dual fluidized bed has been established. The effect of bed material build-up height and gas velocity on the solid circulation rate of CFB (circulating fluidized bed) and BFB (bubble fluidized bed) has been studied. The results show that the solid circulation rate is increased with the increasing of gas velocity Uc and the bed material build-up height. Bed material build-up height of BFB and CFB is changed with the changing of gas velocity Uc. The bed material heights of CFB and BFB have been also investigated in this experiment.

Catalytic Decomposition of N2O over the Bed Material from Circulating Fluidized-Bed (CFB) Boilers Burning Biomass Fuels and Wastes

2004 ◽  
Vol 18 (6) ◽  
pp. 1909-1920 ◽  
Author(s):  
Vesna Barišić ◽  
Ahmad Kalantar Neyestanaki ◽  
Fredrik Klingstedt ◽  
Pia Kilpinen ◽  
Kari Eränen ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Catalytic Decomposition ◽  
Biomass Fuels ◽  
Bed Material

Applications of Feed-Forward Neural Network to Study Irregular-Shape Particle Effects on Hydrodynamics Behavior in a Liquid–Solid Circulating Fluidized Bed Riser

2013 ◽  
Vol 11 (1) ◽  
pp. 443-452 ◽  
Author(s):  
Shaikh Abdur Razzak
Keyword(s):  
Neural Network ◽  
Experimental Data ◽  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Phase Distribution ◽  
Flow Behavior ◽  
Pilot Scale ◽  
Irregular Shape ◽  
Feed Forward Neural Network ◽  
Feed Forward

Abstract Feed-forward neural network (FFNN) modeling techniques are applied to study the flow behavior of different-size irregular-shape particles in a pilot scale liquid–solid circulating fluidized bed (LSCFB) riser. The adequacy of the developed model is examined by comparing the model predictions with experimental data obtained from the LSCFB using lava rocks (dmean 500 and 920 µm) and water as solids and liquid phases, respectively. Axial and radial solid holdup profiles are measured in the riser at four axial locations (H 1, 2, 3 and 3.8 m above the distributor) above the liquid distributor for different operating liquids. In the model training, the effects of various auxiliary and primary liquid velocities, superficial liquid velocities and superficial solid velocities on radial phase distribution at different axial positions are considered. For model validation along with other experimental parameters, dimensionless normalized superficial liquid velocities and net superficial liquid velocities are also introduced. The correlation coefficient values of the predicted output and the experimental data are found to be 0.95 and 0.94 for LR-500 and LR-920 particles, respectively which reflects the competency of the developed FFNN model.

scholarly journals A Comprehensive Assessment of Commercial Process Simulation Software for Compression Moulding of Sheet Moulding Compound

2021 ◽  
Author(s):  
Connie Cheng Qian ◽  
Abhaye Deshpande ◽  
Mona Jesri ◽  
Richard Groves ◽  
Neil Reynolds ◽  
...  
Keyword(s):  
Experimental Data ◽  
Process Simulation ◽  
Simulation Software ◽  
Comprehensive Assessment ◽  
Design Tool ◽  
Compression Moulding ◽  
Constitutive Material Model ◽  
Injection Moulding Process ◽  
Moulding Compound ◽  
Sheet Moulding Compound

With a growing interest in the application of carbon fibre Sheet Moulding Compound (SMC), a number of commercial software packages have been developed for the simulation of compression moulding of SMC. While these packages adopt different algorithms and meshing strategies, the constitutive material model and processing control are usually adapted from injection moulding process simulation. Little has been done in the literature for assessing the capabilities of these software as design tools, and more importantly, validating the process simulation results using experimental data. This paper aims to provide an independent and comprehensive assessment of existing well-known process simulation software for SMC compression moulding. The selected software will be compared in terms of material models, and available processing settings in order to determine their robustness as a compression moulding design tool. The predictive accuracy of the software will also be assessed by comparing the compression force and filling patterns against the experimental data.

scholarly journals Optimization of Temperature of Circulating Fluidised Bed Combustion Boiler Using Conventional Techniques Anova and Rsm

2018 ◽  
Vol 7 (3.8) ◽  
pp. 29
Author(s):  
Suresh Kumar Badholiya ◽  
Anil Kothari ◽  
Sharad Pradhan
Keyword(s):  
Circulating Fluidized Bed ◽  
Sintering Behavior ◽  
Operating Parameters ◽  
Fluidised Bed ◽  
Air Velocity ◽  
Gas Channel ◽  
Equipment Failures ◽  
Rapid Sintering ◽  
Secondary Air ◽  
Bed Material

In recent years, significant advances have been made in understanding and predicting the behavior of ash in combustion and gasification systems. In CFBC boilers ash sintering may contribute to deposit formation in the cyclone, return leg and post cyclone flue gas channel. Rapid sintering can lead to heavy agglomerate formation, which may finally inhibit circulation in dense phase areas (such as seal pot and return leg). Hence understanding the sintering behavior before the coal is used, would be desirable for avoiding problems.The present work is aimed at determining the influence of operating parameters on the temperature of circulating fluidized bed boiler. Ranking given to operating parameters by observing their contribution in the temperature of boiler by combustion of coal. A design of experiments technique was adopted in the form of Taguchi’s L9 orthogonal array. The selected parameters were coal mass flow rate, coal particle size, primary air velocity and secondary air velocity. The combustion has done in modelled CFBC boiler using three quality lignite coal to analyze the temperature. The results were then analyzed and the major contributing factor towards temperature of boiler was found out based on the Analysis of Variance (ANOVA) and Response Surface Methodology (RSM) calculations. Boiler combustor temperature value optimized at targeted temperature value (1220 K) by using above method. The general trend indicates that as the temperature increases the possible of ash agglomeration in those area increases. Ash shows their sticky behavior if combustor temperature increase beyond the Ash fusion temperature ( > 1400 K ). Agglomeration of the bed material manifests itself in various forms within the combustor and associated system components. Ash deposition in the utility boilers is a major problem that may result in decreased efficiency, unscheduled outages, equipment failures, increased cleaning, and high maintenance costs. So this study helped to find out optimum condition for process parameter and to control boiler temperature. 

An Experimental Study on the Fatigue of Structural Steels with Various Welding Details

2008 ◽  
Vol 385-387 ◽  
pp. 593-596
Author(s):  
Byeong Choon Goo
Keyword(s):  
Experimental Data ◽  
Fatigue Strength ◽  
Structural Steel ◽  
Fatigue Tests ◽  
Structural Steels ◽  
Parent Material ◽  
Key Characteristics ◽  
Load Carrying ◽  
Weld Toe ◽  
Ground Load

A structural steel should satisfy various properties under varied conditions. Fatigue strength is one of them. When structural steels are used in the form of welded joints, fatigue strength is one of the key characteristics that should be considered. In this study, comprehensive fatigue tests of a structural steel with yielding strength of about 350 MPa and tensile strength of about 520 MPa were carried out. First, a lot of specimens: parent material plates, butt welded specimens with reinforcement removed, as-welded plates, plates with weld toe ground, load-carrying cruciform, non load-carrying cruciform, plates with transverse fillet welded rib, etc were prepared and tested. S-N curves for the above specimens were compared and analyzed. Secondly, some life-size rectangular beams were fabricated by welding and tested. It is found that annealing is detrimental to fatigue strength rather than beneficial. The experimental data and results may be used usefully by engineers.

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