An Investigation Into the Operation of the Twin-Exit Loop-Seal of a Circulating Fluidized Bed Boiler in a Thermal Power Plant and Its Design Implication

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
Prabir Basu ◽  
Munish Chandel ◽  
James Butler ◽  
Animesh Dutta
Keyword(s):  
Power Plant ◽  
Fluidized Bed ◽  
Thermal Power Plant ◽  
Circulating Fluidized Bed ◽  
Thermal Power ◽  
Scale Model ◽  
Circulation Rate ◽  
Cfb Boiler ◽  
Solids Circulation Rate ◽  
New Findings

Loop-seal is a critical component of a circulating fluidized bed (CFB) boiler, and yet very little information on its working or design is available in published literature. Among the limited available information, none is on twin-exit loop-seal though it is one of the most commonly used loop-seal in large commercial CFB boilers. To circulate larger amounts of solids, a twin-exit loop-seal provides larger solids flow sections. It receives solids from one standpipe but delivers it through two recycle chambers and two delivery pipes. The present research was conducted in a twin-exit loop-seal of a 3.2 MWth CFB boiler operating in a thermal power plant for cofiring purpose. Data obtained in this industrial unit were supplemented with those collected in a single-exit bench-scale loop-seal in the authors’ laboratory from the single-exit loop-seal in a 65 t/h CFB boiler and a scale model of a 30 MW CFB boiler. The effect of recycle chamber’s aeration on the solids circulation rate was studied for several particle sizes. Results suggest that the total solids circulation rate does not increase proportionately with the increase in loop-seal discharge area provided by the twin-exit loop-seals. The linear horizontal velocities of solids and the minimum aeration in the recycle chambers are comparable to those measured in a single-exit loop-seal. The implication of these new findings on the design procedure of loop-seals is discussed.

scholarly journals Cost Management of a CFBC Boiler in a Thermal Power Plant

2019 ◽  
Vol 8 (6S2) ◽  
pp. 883-887
Keyword(s):  
Power Plant ◽  
Fluidized Bed ◽  
Thermal Power Plant ◽  
Circulating Fluidized Bed ◽  
Thermal Power ◽  
Thermal Capacity ◽  
Fluidized Bed Combustion ◽  
Magnetic Separator ◽  
Power Stations ◽  
Bed Material

India, being the world's third most noteworthy power maker with all out exhibited purpose of containments of 344.69 GW, contributing 68% of thermal Capacity. Subsequently, Thermal power producing stations are basic. As an electrical architect, exceptional consideration ought to be taken to decrease coal utilization in Thermal power generating stations. In Thermal power producing stations, boilers utilized are Circulating Fluidized Bed Combustion (CFBC) and Atmospheric Fluidized Bed Combustion (AFBC). These boilers utilize bed material to keep up warmth in the boiler. 210MW and under 210 MW generators in the Thermal power producing stations are utilizing CFBC boilers. After a nearby examination of thermal power stations, it is discovered that the bed material including over 5% of engaging parts are open in the bed material which is horrendous. This happens where magnetic separator at the bed material stacking point is missing or far off. From this time forward it is proposed to introduce a magnetic separator at the bed material stacking point. With this establishment of magnetic separator hardware, boiler efficiency can be reached out to 2.1% more, to keep up the required temperature and to maintain a strategic distance from boiler stoppages. An endeavor has been made to perceive the usage required presenting attractive separator and it has been discovered that the reward period is obliged to roughly 1 to 2 years if the engaging sections in the bed material are 5%and 10% respectively. The Proposed issue is endeavored with MATLAB condition and cost examination of thermal power plant is separated and existing synthesis information. The test outcomes displayed that the proposed framework gives an attainable game-plan gigantic theory saves and liberal for consistent assignments.

Performance evaluation of a supercritical circulating fluidized bed boiler for power generation under flexible operation

2021 ◽  
pp. 095765092199396
Author(s):  
Matteo Bruzzone ◽  
Silvia Ravelli
Keyword(s):  
Power Generation ◽  
Fluidized Bed ◽  
High Performance ◽  
Circulating Fluidized Bed ◽  
Thermal Power ◽  
Rankine Cycle ◽  
Hard Coal ◽  
Cfb Boiler ◽  
Power Cycles ◽  
Commercial Code

It is well known that the Łagisza power plant in Poland is the world’s first supercritical circulating fluidized bed (CFB) boiler, whose commercial operation started on June 2009. It has attracted a great deal of interest and operational data are publicly available, therefore it has been chosen as the object of the present study aimed at assessing load and fuel flexibility of supercritical CFB plants. First, the thermal cycle was modelled, by means of the commercial code Thermoflex®, at nominal and part load conditions for validation purposes. After having verified the validity of the applied modelling and simulation tool, the advantage of having supercritical steam combined with CFB boiler over subcritical steam and pulverized coal (PC) boiler, respectively, was quantified in terms of electric efficiency. As a next step, the designed fuel, i.e. locally mined hard coal, was replaced with biomass: 100% biomass firing was taken into account in the case of subcritical CFB boiler whereas the maximum share of biomass with coal was set at 50% with supercritical CFB boiler, consistently with the guidelines provided by the world leading manufacturers of CFB units. A broad range of biomass types was tested to conceive mixtures of fuel capable of preserving quite high performance, despite the energy consumption in pretreatment. However, the overall efficiency penalty, due to biomass co-firing, was found to potentially undermine the benefit of supercritical steam conditions compared to conventional subcritical power cycles. Indeed, the use of low-quality biomass in thermal power generation based on steam Rankine cycle may frustrate efforts to push the steam cycle boundaries.

The Performance of a Loop Seal in a CFB Boiler

2006 ◽  
Vol 128 (2) ◽  
pp. 135-142 ◽  
Author(s):  
Andreas Johansson ◽  
Filip Johnsson ◽  
Bengt-Åke Andersson
Keyword(s):  
Heat Transfer ◽  
Flow Pattern ◽  
Fluidized Bed ◽  
Scaling Laws ◽  
Circulating Fluidized Bed ◽  
Vertical Direction ◽  
Scale Model ◽  
Corrosive Environment ◽  
Cfb Boiler ◽  
Load Conditions

High in-bed heat transfer and low corrosive environment imply that the loop seal of a circulating fluidized bed (CFB) boiler is an advantageous location for superheaters. In order to increase the knowledge on the flow pattern and the heat transfer distribution to the tubes within a loop seal, measurements were performed in the loop seal of a 30MW CFB boiler as well as in a 1∕3 scaled-down seal operated according to simplified scaling laws. The scale model measurements show that the solids recirculation flux can be maintained with a substantial decrease of the fluidization flow in the seal compared to that currently used at full load conditions. It was also possible to significantly decrease the fraction of the bottom of the seal that was fluidized without affecting the solids flux through the seal. A gradient in the solids flow were detected in the vertical direction.

scholarly journals An Optimization Model for Tramp Ship Scheduling considering Time Window and Seaport Operation Delay Factors

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Ang Yang ◽  
Yu Cao ◽  
Kang Chen ◽  
Qingcheng Zeng ◽  
Zigen Chen
Keyword(s):  
Power Plant ◽  
Thermal Power Plant ◽  
Large Scale ◽  
Time Window ◽  
Programming Model ◽  
Thermal Power ◽  
Scale Model ◽  
Mixed Integer ◽  
Ship Scheduling ◽  
Operation Cost

The quantity of electrical coal transported through the tramp shipping network is increasing due to the high demands. This trend has increased the scheduling difficulty combined with the underdevelopment of the private thermal power plant port. The high coal consumption and low port storage capacity requires the scheduling of the tramp ship to be on a strict time window to ensure the continuous operation of the thermal power plant. The low port unloading capacity often leads to the port congestion and delay of the unloading operation. This paper develops a mixed-integer-programming model for the optimization of the tramp ship scheduling to reduce the total operation cost, including the transportation cost and the unloading waiting cost, and the branch-and-price algorithm is adopted to solve this large-scale model. The model and algorithm are tested with historical operation data from the thermal power plant in the southern coastal areas of China. The optimized scheme significantly reduces the total operation cost by reducing the unloading waiting time and the number of active vessels in certain periods. The results also demonstrate the algorithm improvement in the aspects of the optimization quality and efficiency comparing with the heuristic solution.

The control of bed height and solids circulation rate in the standpipe of a cold flow circulating fluidized bed

2005 ◽  
Vol 150 (3) ◽  
pp. 176-184 ◽  
Author(s):  
Juchirl Park ◽  
Yue Huang ◽  
Richard Turton ◽  
Parviz Famouri ◽  
Edward J. Boyle
Keyword(s):  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Circulation Rate ◽  
Cold Flow ◽  
Bed Height ◽  
Solids Circulation Rate

A method for estimating the solids circulation rate in a closed-loop circulating fluidized bed

2001 ◽  
Vol 121 (2-3) ◽  
pp. 213-222 ◽  
Author(s):  
Shantanu Roy ◽  
Abdenour Kemoun ◽  
Muthanna Al-Dahhan ◽  
M.P Dudukovic
Keyword(s):  
Fluidized Bed ◽  
Closed Loop ◽  
Circulating Fluidized Bed ◽  
Circulation Rate ◽  
Solids Circulation Rate
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