Relationship between Solid Flow Rate and Pressure Drop in the Riser of a Pressurized Circulating Fluidized Bed

Khurram, Muhammad Shahzad; Choi, Jeong-Hoo; Won, Yoo Sube; Jeong, A-Reum; Ryu, Ho-Jung

doi:10.1252/jcej.15we080

Cited by 17 publications

(3 citation statements)

References 6 publications

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“…Signifcant diferences are observed between BFB and CFB, which are mainly shown in the following three aspects: (1) Te combustion fraction of BFB is up to 75-95%, while the combustion fraction of CFB is generally 50-60%. (2) However, compared with BFB, temperature of CFB furnace is more uniform and gas-solid contact efciency is higher, which lead to higher combustion efciency obtained for CFB [30]. (3) Compared with CFB, BFB fts for various fuels with particle size in a wide range of 0-50 mm and lower calorifc value, such as straw, peat, lignite, and coke powder [31].…”

Section: Efect Of Type Of Fluidizationmentioning

confidence: 99%

A Review on the Application of Circulating Fluidized Bed Fly Ash in Building Materials

Jia

Wang

Yang

2022

Advances in Materials Science and Engineering

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Circulating fluidized bed (CFB)-based coal burning technology is a type of clean coal combustion technology. Owing to its characteristics of low temperature combustion and desulfurization in furnace, the CFB fly ash is quite different from ordinary fly ash. Based on the comprehensive understanding of physical and chemical characteristics of CFB fly ash, this review summarizes the research progress of the application of CFB fly ash in Portland cement, magnesium oxysulfate (MOS) cement, solid-waste–based cementitious material (SWCM), concrete, geopolymer, artificial aggregate, and other building materials. The study shows that CFB fly ash can improve the early physical and mechanical properties and reduce the drying shrinkage properties for cementitious materials. Its unique chemical composition endows it with good application performance in the MOS cement, geopolymer, and SWCM. However, unfavorable characteristics of CFB fly ash, such as loose and porous structure, self-hardening behavior, and expansibility greatly hinder its practical applications in building materials. Therefore, some measures, such as addition of rational water-reducing agent, ultrafine grinding, mixing of ordinary fly ash, controlling the dosage of CFB fly ash, and water-cement ratio, must be taken to improve the negative influence of CFB fly ash on the building materials, in order to expand its application range. This article summarizes the application and research status of CFB fly ash in building materials, aiming at further promoting the research studies on CFB fly ash resource utilization in building materials and improving the efficiency of CFB fly ash resource utilization.

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Section: Efect Of Type Of Fluidizationmentioning

confidence: 99%

A Review on the Application of Circulating Fluidized Bed Fly Ash in Building Materials

Jia

Wang

Yang

2022

Advances in Materials Science and Engineering

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“…To address the large number of variables that affect the fluid-particle drag, a number of correlations have been developed for determining the solids mass flux ( G s ), or W s , from riser operating variables and particle properties. − As an example, Alghamdi et al developed a kinetic model that uses pressure drop measurements and an estimate of the mass fraction ( x ) of upward flowing solids relative to the sum that is moving both upward and downward. The value of x is obtained from a semiempirical model developed by Rhodes et al This analysis was extended to determining the solids holdup in the upper section of a riser in circulating and interconnected fluidized beds .…”

Section: Introductionmentioning

confidence: 99%

Determining the Solids Mass Flow Rate in a Gas–Solids Riser Using an Integral Momentum Balance

Paccione

2022

Ind. Eng. Chem. Res.

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Determining the solids mass flow rate (W s ) in a gas−solids riser often entails closing a one-dimensional, two-fluid model by relating the total wall friction (F w ) and the drag coefficient (C d ) to riser conditions. However, this requires relating these two parameters to several riser variables making it difficult to apply these relations generally. In this work, closure is obtained using a model for the conservation of linear momentum in the acceleration (entrance region) of a riser. The model relates the total forces imposed on the control volume to the change in linear momentum of the solids. Additional expressions are obtained from the model which provide a means for defining the boundary condition at the entrance to the control volume. The resulting model provides a means of determining the solids mass flow rate (W s ) from three readily measured and physically relevant riser operating parameters: the dynamic pressure drop across the acceleration section (ΔP a ), the normalized dynamic pressure gradient at the end of the acceleration section (P a ′(1)), and the superficial gas velocity (U) in a riser. The agreement between measured and model values ranges from very good to excellent with the average absolute deviation being <5% of the measured values.

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“…In CFBC, some solid particles blown out and circulate again through cyclone in the boiler. The major issue to be addressed in CFBC is that the solid circulation rate in boiler is measured by conventional methods which are unable to provide reliable accuracy at high pressure because of non-linearity [21,22]. So, there is a need to design a soft computing base controller.…”

Section: Introductionmentioning

confidence: 99%

Estimation of the Solid Circulation Rate in Circulating Fluidized Bed System Using Adaptive Neuro-Fuzzy Algorithm

et al. 2021

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Circulating Fluidized Bed gasifiers are widely used in industry to convert solid fuel into liquid fuel. The Artificial Neural Network and neuro-fuzzy algorithm have immense potential to improve the efficiency of the gasifier. The main focus of this article is to implement the Artificial Neural Network and Adaptive Neuro-Fuzzy Inference System modeling approach to estimate solid circulation rate at high pressure in the Circulating Fluidized Bed gasifier. The experimental data is obtained on a laboratory scale prototype in the Chemical Engineering laboratory at COMSATS University Islamabad. The Artificial Neural Network and Adaptive Neuro-Fuzzy Inference System use four input features—pressure, single mean diameter, total valve opening and riser dp—and one output feature mass flow rate with multiple neurons in the hidden layers to estimate the flow of solid particles in the riser. Both Artificial Neural Network and Adaptive Neuro-Fuzzy Inference System model worked on 217 data samples and output results are compared based on their Mean Square Error, Regression analysis, Mean Absolute Error and Mean Absolute Percentage Error. The experimental results show the effectiveness of Adaptive Neuro-Fuzzy Inference System (Mean Square Error is 0.0519 and Regression analysis R2=1.0000), as it outperformed Artificial Neural Network in terms of accuracy (Mean Square Error is 1.0677 and Regression analysis R2=0.9806).

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Relationship between Solid Flow Rate and Pressure Drop in the Riser of a Pressurized Circulating Fluidized Bed

Cited by 17 publications

References 6 publications

A Review on the Application of Circulating Fluidized Bed Fly Ash in Building Materials

A Review on the Application of Circulating Fluidized Bed Fly Ash in Building Materials

Determining the Solids Mass Flow Rate in a Gas–Solids Riser Using an Integral Momentum Balance

Estimation of the Solid Circulation Rate in Circulating Fluidized Bed System Using Adaptive Neuro-Fuzzy Algorithm

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