Microstructural development of product layer during limestone sulfation and its relationship to agglomeration in large-scale CFB boiler

Energy ◽  
2021 ◽  
pp. 121872
Author(s):  
Dongfang Li ◽  
Xiaoxiao Qu ◽  
Junjie Li ◽  
Suck Won Hong ◽  
Chung-hwan Jeon
Keyword(s):  
Large Scale ◽  
Product Layer ◽  
Microstructural Development ◽  
Cfb Boiler

Model-Based Analysis of Transient Behavior of Large Scale CFB Boilers

2003 ◽  
Author(s):  
Ari Kettunen ◽  
Timo Hyppa¨nen ◽  
Ari-Pekka Kirkinen ◽  
Esa Maikkola
Keyword(s):  
Flow Rate ◽  
Large Scale ◽  
Air Flow ◽  
Model Parameters ◽  
Air Flow Rate ◽  
Process Data ◽  
Cfb Boiler ◽  
Flow Rates ◽  
Load Change ◽  
Secondary Air

The main objective of this study was to investigate the load change capability and effect of the individual control variables, such as fuel, primary air and secondary air flow rates, on the dynamics of large-scale CFB boilers. The dynamics of the CFB process were examined by dynamic process tests and by simulation studies. A multi-faceted set of transient process tests were performed at a commercial 235 MWe CFB unit. Fuel reactivity and interaction between gas flow rates, solid concentration profiles and heat transfer were studied by step changes of the following controllable variables: fuel feed rate, primary air flow rate, secondary air flow rate and primary to secondary air flow ratio. Load change performance was tested using two different types of tests: open and closed loop load changes. A tailored dynamic simulator for the CFB boiler was built and fine-tuned by determining the model parameters and by validating the models of each process component against measured process data of the transient test program. The know-how about the boiler dynamics obtained from the model analysis and the developed CFB simulator were utilized in designing the control systems of three new 262 MWe CFB units, which are now under construction. Further, the simulator was applied for the control system development and transient analysis of the supercritical OTU CFB boiler.

Biomass and Coal Co-Combustion in Utility Scale: Operating Experience of Alholmens Kraft

2005 ◽  
Author(s):  
Ari Kokko ◽  
Marko Nylund
Keyword(s):  
Large Scale ◽  
Energy Content ◽  
Operating Experience ◽  
District Heating ◽  
Fuel Mixture ◽  
High Moisture ◽  
Auxiliary Equipment ◽  
Wood Residue ◽  
Cfb Boiler ◽  
Fuel Components

CFB technology has been scaled-up and demonstrated in the size range of around 250 MWe. One of the biggest advantages of CFB is it’s capability to burn different kind of fuels either at the same time or separately. The utilization of biomass alone or in co-combustion with coal has been demonstrated in this size scale in Alholmens Kraft CFB for three years now. Alholmens Kraft produces electricity for owners in Finland and in Sweden and also supplies process steam to the nearby UPM-Kymmene paper mill, and for district heating in town of Pietarsaari, Finland. The CFB boiler capacity is maximum 240 MWe. The Alholmens Kraft CFB boiler is a multi-fuel boiler, whose main fuels are bark, wood residue and peat, with coal as a support and back-up fuel. Bark and wood residue are low calorific, high moisture fuels with varying energy content and having also very heterogeneous physical properties. Peat is also low calorific fuel with high moisture content but with much more stable quality. Fuel consumption utilizing these fuel components is about 20 000 m3/d (700 000 ft3/d), which sets huge challenges to the whole logistic chain of fuel procurement. The maximization of CO2 neutral fuels is favoured, but some higher heating value and always available fuel, coal, is needed to ensure the high plant availability. Fuel mixture is variating all the time and it is optimized to fulfil operational, environmental and economical requirements. This paper describes the experience of using several fuel components in different operational situations during first three years of operation. The paper introduces also experiences of auxiliary system needed for reliable operation in co-combustion. The paper will also introduce the experience of the boiler controllability — changing load or fuel mixture — with this heterogeneous fuel combination. The co-combustion of biomass and coal is a real opportunity also in a large scale when including certain additional features in boiler and auxiliary equipment design. Interest towards co-combustion seems to be continuous-design considerations of a new boiler project of the same size is introduced in this paper.

DeNOx Technology Selection and Optimal Design of SNCR System for a 300MWe CFB Boiler

2014 ◽  
Vol 492 ◽  
pp. 7-12
Author(s):  
Wei Gang Huang ◽  
Jing Ji Li ◽  
Hai Rui Yang
Keyword(s):  
Optimal Design ◽  
Large Scale ◽  
Flow Chart ◽  
Technology Selection ◽  
Outer Side ◽  
Cfb Boiler ◽  
Safety Concerns ◽  
Whole Process ◽  
Emission Regulation ◽  
Cfd Method

With the increasing pressure on NOx removal in China, a part of CFB boilers have to install the deNOx devices to meet the updated emission regulation. Aiming to the large-scale 300MWe CFB boilers, the existing SCR and SNCR technologies are compared and the SNCR technology using urea as reductant is recommended based on the technical, economic and safety concerns. The design of the SNCR system is also presented. By employing the CFD method, the different urea distributions inside the cyclone are illustrated and the layout of 10 nozzles for each cyclone is optimized to the outer side of cyclone inlet. The technological flow chart of the SNCR system is given to show the whole process of urea storage, transport and injection.

Model Research of Gas Emissions From Lignite and Biomass Co-Combustion in a Large Scale CFB Boiler

2014 ◽  
Vol 35 (2) ◽  
pp. 217-231 ◽  
Author(s):  
Jarosław Krzywański ◽  
Rafał Rajczyk ◽  
Wojciech Nowak
Keyword(s):  
Experimental Data ◽  
Coal Combustion ◽  
Large Scale ◽  
Forest Biomass ◽  
Fluidised Bed ◽  
Fuel Blend ◽  
Energy Fraction ◽  
Cfb Boiler ◽  
Fuel Blends ◽  
Combustion Modelling

Abstract The paper is focused on the idea of a combustion modelling of a large-scale circulating fluidised bed boiler (CFB) during coal and biomass co-combustion. Numerical computation results for three solid biomass fuels co-combustion with lignite are presented in the paper. The results of the calculation showed that in previously established kinetics equations for coal combustion, some reactions had to be modified as the combustion conditions changed with the fuel blend composition. Obtained CO2, CO, SO2 and NOx emissions are located in borders of ± 20% in the relationship to the experimental data. Experimental data was obtained for forest biomass, sunflower husk, willow and lignite cocombustion tests carried out on the atmospheric 261 MWe COMPACT CFB boiler operated in PGE Turow Power Station in Poland. The energy fraction of biomass in fuel blend was: 7%wt, 10%wt and 15%wt. The measured emissions of CO, SO2 and NOx (i.e. NO + NO2) were also shown in the paper. For all types of biomass added to the fuel blends the emission of the gaseous pollutants was lower than that for coal combustion.

Validation of the oxygen buffering ability of bed materials used for OCAC in a large scale CFB boiler

2017 ◽  
Vol 316 ◽  
pp. 462-468 ◽  
Author(s):  
Fredrik Lind ◽  
Angelica Corcoran ◽  
Henrik Thunman
Keyword(s):  
Large Scale ◽  
Cfb Boiler ◽  
Bed Materials ◽  
Materials Used

Status and Prospect of Large-Scale Circulating Fluidized Bed Boiler

2012 ◽  
Vol 516-517 ◽  
pp. 444-447
Author(s):  
Da Fu Ma ◽  
Xiao Hong Hao
Keyword(s):  
Fluidized Bed ◽  
Co2 Capture ◽  
Power Plants ◽  
Large Scale ◽  
Circulating Fluidized Bed ◽  
Present Situation ◽  
Supercritical Pressure ◽  
High Density ◽  
Cfb Boiler ◽  
Fluidized Bed Gasifier

The paper is focused on the present situation and the development of large-scale circulating fluidized bed (CFB) boilers. Several developed technology of CFB such as supercritical and ultra supercritical pressure CFB boilers for power plants, oxy-fuel CFB boiler for CO2 capture and high-density circulating fluidized bed gasifier for advanced IGCC/IGFC are introduced in this paper.

Ukraine’s First Large-Scale CFB 200 MWe Anthracite Fired Starobeshevo Power Plant

2005 ◽  
Author(s):  
Victor A. Shevtchenko ◽  
Werner Franke ◽  
Peter Gummel ◽  
Marian Kotrus ◽  
George von Wedel
Keyword(s):  
Power Plant ◽  
Steam Turbine ◽  
Power Plants ◽  
Large Scale ◽  
State Of The Art ◽  
Design Issues ◽  
Cfb Boiler ◽  
Commercial Operation ◽  
European Regulations ◽  
Temperature And Pressure

JSC Donbassenergo, a major utility in the Ukraine, is operating power plants of approx. 3500 MW, mostly operated with their local fuel anthracite. As the existing facilities are reaching their age a strategy has been developed to apply state-of-the-art technology for revamping. On this basis the decision has been taken to replace boiler No. 4 of the Starobeshevo Power Plant with a boiler based on CFB technology. The unit is designed for 670 t/h of superheated and 538 t/h of reheated steam with 545 / 543 °C and 13.2 / 2.5 MPa temperature and pressure to account for the existing steam turbine which generates 200 MW electricity. Fuels used are a local anthracite and anthracite sludge left from coal washing and which is available in large quantities. Emissions are designed in accordance with European regulations allowing 200 mg/m3 (STP) for NOX and 200 mg/m3 (STP) for SO2. A basic description of the overall plant will be given. Details on the design of the CFB boiler which is equipped with Lurgi’s patented pant-leg and other design issues will be explained. Operating results from the commissioning and first commercial operation will be presented.

The Influence of Sulfur Additions on the Corrosive Environments in a Waste-Fired CFB Boiler

2006 ◽  
Vol 522-523 ◽  
pp. 563-570 ◽  
Author(s):  
J. Pettersson ◽  
C. Pettersson ◽  
Nicklas Folkeson ◽  
Lars Gunnar Johansson ◽  
Erik Skog ◽  
...  
Keyword(s):  
Field Tests ◽  
Product Layer ◽  
Household Waste ◽  
Gas Temperature ◽  
Fireside Corrosion ◽  
Protective Oxide ◽  
Cfb Boiler ◽  
Corrosion Product Layer ◽  
Corrosive Environments ◽  
Alkali Chlorides

Corrosion/deposition field tests have been carried out in the superheater region of a commercial waste-fired 75MW CFBC boiler using air cooled probes. The influence of material temperature (450-500°C), flue gas temperature, temperature variations (i.e. thermal cycling) and additives to the fuel (elemental sulphur and dolomite) on deposition and corrosion was studied. The results presented here mainly consider the influence of sulphur additions to the fuel. The fuel was a mixture of 50% household waste and 50% industrial waste. After exposure the samples were analyzed by ESEM/EDX, XRD, AAS, FIB and IC. With no additional sulphur, alkali chlorides made up a large part of the deposit/corrosion product layer and in some cases chromate (VI) was detected. It is suggested that the chromate (VI) has formed by reaction of the protective oxide with alkali chlorides in the deposit. Adding sulphur to the fuel changed the composition of the deposits, alkali chlorides being largely replaced by alkali sulphates. No chromates(VI) were detected in the sulphur-added runs. It is suggested that adding sulphur to the fuel may decrease fireside corrosion because it changes the composition of the deposit. Alkali sulphates are much less corrosive than alkali chlorides partly because they do not form chromate(VI).

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