Numerical Simulations for Performance Optimization of Circulating …

Geometry of Circulating Fluidized Bed. The schematic of the furnace along with the cyclone is shown in Fig. 1. From modeling perspective, the geometry is divided into Zone 1 and Zone 2. Zone 1 consists of furnace bed, primary air nozzle, and tube bundles.

Operation Optimization of Circulating Fluidized Bed …

from a boiler with similar furnace structure and corresponding simulation results. The SA distribution appeared to be basically uniform in the furnace. Even so, the oxygen concentration decreased gradually along the width direction and reached its minimum in the middle of the furnace; the deviation between the internal and lower SA was about 17%.

Fluidized Bed Furnace

For the same fuel input the circulating fluidized bed has smaller furnace cross section than corresponding bubbling fluidized bed. This means that a CFB with same furnace width and depth than a BFB can burn more fuel. When the flue gas upward velocity is increased past the bubbling regime, part of the sand and ash in the bed become entrained ...

Frost Resistance and Mechanism of Circulating Fluidized …

The motivation of this work is to enhance the long-term frost resistance of circulating fluidized bed fly ash (CFA)-based multisolid waste cementitious material (CSM). In this research, CSM2 is prepared by 30 wt.% CFA, 20 wt.% blast furnace slag (BFS), 10 wt.% red mud (RM), 10 wt.% phosphorus slag (PS), and 30 wt.% cement clinker (CC). The strength and …

Calculation and Analysis of Heat Transfer Coefficients in a Circulating …

A new way for the circulating fluidized bed (CFB) boiler research is proposed by the supervisory information system (SIS) in power plant level. The heat transfer coefficient in CFB boiler furnace is calculated and analyzed by the SIS calculation analysis in a commercial CFB boiler, the way how to calculate the heat transfer coefficient in SIS is introduced, and the heat transfer coefficient is ...

Solids Flow in Large-Scale Circulating Fluidized Bed Furnaces …

The flow pattern of solids established in large-scale circulating fluidized bed (CFB) furnaces is of great importance for the performance of commercial CFB boilers, as it governs the heat transfer and mixing of the fuel and any other reactive solids. The solids flow pattern in the riser is crucial for the design and scaling up of large-scale CFB technologies for the thermochemical …

The Study of Dynamic Processes in the Boiler Furnace with Circulating …

The paper presents a numerical simulation of the furnace with a circulating fluidized bed. Numerical study carried out for the bottom of the combustion chamber with the varying heights of volume ...

Progress of Combustion in an Oxy-fuel Circulating Fluidized-Bed Furnace

Oxy-fuel combustion, which is a promising technology for the abatement of carbon dioxide emissions, can be applied in circulating fluidized-bed (CFB) power plants.

CFD simulations of gas–solid flow in an industrial-scale circulating

This leads to an overestimation of the gas–solid drag force and a false prediction of the flow field. For these cases, a correction must be formulated for the gas–solid drag. We have simulated a large-scale circulating fluidized bed furnace using different gas–solid drag models and compared the model results with measurements.

(PDF) Circulating Fluidized Beds

The gas backmixing characteristics and residence time distribution in a riser of circulating fluidized bed with 140mm i.d. were investigated by means of gas tracer technique. The gas dispersion ...

Development and technical progress in large-scale circulating fluidized …

Circulating fluidized bed (CFB) boilers has realized the clean and efficient utilization of inferior coal like gangue and coal slime, high sulfur coal, anthracite, petroleum coke, oil shale and other resources. As a country with the largest amount of CFB boilers and the largest installed capacity in the world, China has 440 100–600 MWe CFB boilers with a total capacity …

Suriname Circulating Fluidized Bed Gasifier

Suriname Circulating Fluidized Bed Gasifier - Haiqi provides intelligent solutions for energy producers. Through the coupling and complementation between different energy types, the …

(PDF) Furnace design of 210 MW circulating fluidized bed …

A simple circulating fluidized bed (CFB) combustion riser was modeled for computational fluid dynamics (CFD) to study the hydrodynamics of gas-solid flow in a circulating fluidized bed riser to ...

CFB: Technology of the Future?

Back in the 1980s, circulating fluidized bed (CFB) technology was a little like integrated gasification combined cycle (IGCC) today: coal generation's technology of the future.

Progress of combustion in the furnace of a circulating fluidized …

Twenty-Sixth Symposium (International) on Combustion/The Combustion Institute, 1996/pp. 3253–3259 PROGRESS OF COMBUSTION IN THE FURNACE OF A CIRCULATING FLUIDIZED BED BOILER ANDERS LYNGFELT, LARS-ERIK A° MAND and BO LECKNER Chalmers University of Technology Go¨teborg, Sweden Gas concentrations were measured in …

Numerical simulation of gasification characteristics in a circulating …

In the computational particle fluid dynamics method, a numerical model of a three-dimensional circulating fluidized bed (CFB) air-water vapor mixture was established. This model facilitated an investigation of the characteristics of the biomass gasification process in a CFB gasifier. This study systematically examined the impact of variables such as fluidized gas …

Waste-to-resource strategies for the use of circulating fluidized …

Circulating fluidized bed (CFB) boilers are considered a clean combustion technology [[1], [2], [3], [4]].CFB boilers have several competitive advantages, such as high combustion efficiency (97.5–99.5%) [5], low combustion temperatures (typically in the range of 850–900 °C) [6], low polluting gas emissions (SO 2 and NO x) [7], and wide fuel flexibility.

Circulating Fluidized Bed Combustion

Fluidized bed combustion (FBC) is a well-established commercial combustion technology, in which combustion occurs in the presence of high concentrations of solids, typically sand, ash or that derived from limestone, if in-situ sulphur capture is required (i.e., a bed), which are fluidized in a stream of combustion air. It exists in two forms: one in which a well-defined bed exists, which …

Internal Recirculation Circulating Fluidized-Bed Boilers

R-CFB has significantly lower furnace exit gas velocity. By relying on internal recirculation, the IR-CFB design eliminates J-valves, loop seals, and high-pr. ssure blowers which are required …

Fluidization Characteristics of Circulating Fluidized Bed Boilers

The fluidization in the furnace of circulating fluidized bed (CFB) boilers is described. Data have been obtained from a 12 MW th CFB boiler and from literature. The bottom bed is bubbling rather than fast or turbulently fluidized as is often assumed. There is an extended splash zone above this bed, in which particles are thrown up by the ...

Analysis on Combustion System of Circulating Fluidized …

circulating fluidized bed boiler operation controlsound. system, and established a perfect dynamic mathematical model by adjusting the air supply, coal supply and slag discharge. Based on this model, the change of material concentration and distribution position in the furnace chamber of the circulating fluidized bed boiler under

Optimization of Fluidization State of a Circulating Fluidized …

To reduce the auxiliary power consumption and improve the reliability of large-scale circulating fluidized bed (CFB) boilers, we developed energy-saving CFB combustion technology based on the fluidization state re-specification. A calculation model of coal comminution energy consumption was used to analyze the change in comminution energy …

Smelter Grade Alumina CFB Calcination Plant Solution

's CFB (Circulating Fluidized Bed) Alumina Calcination technology enables you to produce superior quality alumina with minimum impact on the environment and at reduced specific fuel …

Influence of Operating Parameters on NOx and SO2 …

Post-combustion technology of circulating fluidized bed can largely reduce the emission of nitrogen oxides (NOx) in the process of combustion and succeed in meeting the ultra-low NOx standard for some fuels like Shenmu coal. Exploring the potential of synergistic control of the emissions of NOx and sulphur dioxide (SO2) under post-combustion technology has …

(PDF) An update of circulating fluidised bed combustion (CFB

Studies on circulating fluidized bed (CFB) boilers have being conducted at the Tsinghua University (TH) for about two decades and much of works are done to link the fundamentals with practical ...

Fluidization Characteristics of Circulating Fluidized Bed Boilers

The fluidization in the furnace of circulating fluidized bed (CFB) boilers is described. Data have been obtained from a 12 MW th CFB boiler and from literature. The bottom bed is bubbling …

Progress of circulating fluidized bed combustion …

The gas–solid flow above the dense bed is known as fast fluidization [].Previous studies have shown that the axial profile of particle concentration is influenced by many factors, including the superficial gas velocity, the bed inventory, the solid circulation rate and the bed geometric structure [].As the flow resistance is relatively small in loop seals and the furnace …

CFD simulations of gas–solid flow in an industrial-scale …

Shah et al. (2009). In large-scale CFD simulations of CFB furnaces, the reactions are often ignored and the furnace is assumed to be isothermal (e.g. Zhang et al., 2010). This is acceptable because the proportion of the gas flow because of reactions is relatively small and the temperature profile in a CFB furnace is fairly uniform. In

A Three-Dimensional Model Frame for Modelling …

In a large-scale circulating fluidized bed furnace, the local feeding of fuel, air, and other input materials, and the limited mixing rate of different reactants produce spatially non-uniform process conditions. To simulate the real conditions, the furnace should be modelled three-dimensionally or the three-dimensional effects should be accounted for. The fluidized beds can …

B&W Clean Power Production Case Studies » Babcock

The addition of limestone to the circulating bed reduces SO2 emissions from the boiler. Low furnace temperatures and staged combustion limit NOx emissions. Unique two-stage solids …