Modelling Combustion Process in Circulating Fluidised Bed Boiler: A Fuzzy Graph Approach

2014 ◽  
pp. 267-274
Author(s):  
Razidah Ismail ◽  
Sumarni Abu Bakar ◽  
Nurul Syazwani Yusof
Keyword(s):  
Combustion Process ◽  
Fluidised Bed ◽  
Fuzzy Graph ◽  
Circulating Fluidised Bed

scholarly journals Data-driven control for combustion process of circulating fluidised bed boiler

2020 ◽  
Vol 5 (1) ◽  
pp. 39-48
Author(s):  
Fang Fang ◽  
Songyuan Yu ◽  
Le Wei ◽  
Yajuan Liu ◽  
Jizhen Liu
Keyword(s):  
Combustion Process ◽  
Data Driven ◽  
Fluidised Bed ◽  
Circulating Fluidised Bed

Effects of pressure on flow regimes transition velocities and bubble properties in a pilot-scale pressurised circulating fluidised bed

2021 ◽  
Vol 410 ◽  
pp. 128438
Author(s):  
Xiaoli Zhu ◽  
Pengfei Dong ◽  
Zhiping Zhu ◽  
Raffaella Ocone ◽  
Wuqiang Yang ◽  
...  
Keyword(s):  
Flow Regimes ◽  
Pilot Scale ◽  
Fluidised Bed ◽  
Circulating Fluidised Bed ◽  
Bubble Properties

Gas Mixing in a Pilot Scale (500 kWth) Air Blown Circulating Fluidised Bed Biomass Gasifier

2008 ◽  
pp. 452-464 ◽  
Author(s):  
S.R.A. Kersten ◽  
R.H.W. Moonen ◽  
W. Prins ◽  
W.P.M. van Swaaij
Keyword(s):  
Pilot Scale ◽  
Fluidised Bed ◽  
Gas Mixing ◽  
Circulating Fluidised Bed

scholarly journals Formation of Incrustations during the Cocombustion of Biomass in Fluidised Bed Boilers

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Petr Buryan
Keyword(s):  
Raw Materials ◽  
Combustion Process ◽  
Power Equipment ◽  
Fluidised Bed ◽  
Boiler Furnace ◽  
Repeated Heating ◽  
Equipment Operation ◽  
Heating And Cooling ◽  
First Pass ◽  
Pass Through

In this article, we focus on causes of formation of incrustations in fluidised bed boilers that result from combustion of biomass-containing energy-producing raw materials and can significantly limit the efficiency of the respective power equipment operation. We applied laboratory procedures followed for assessment of characteristic eutectics of mixtures of coal ashes, desulphurisation components (dolomite and limestone), and woodchip ashes. Our analysis proved that combustion of these (or similar) raw materials, accompanied by repeated heating and cooling of combustion and flue gas desulphurisation products, leads to the formation of unfavourable incrustations. These incrustations can grow up to several tens of centimetres in size, thereby significantly restricting the power equipment functionality. They arise due to incrust reheating that results in the formation of eutectics, which have lower melting temperatures than that during their first pass through the combustion process. The same holds for desulphuriation components themselves. Formation of these new eutectics can be attributed both to recycling of substances produced during the first pass through the furnace as well as to mixtures formed both from recycled materials and from components initially combusted in the boiler furnace.

Operation of a Circulating Fluidised Bed Biomass Gasifier

2004 ◽  
Author(s):  
Guanyi Chen ◽  
Gang Li ◽  
Michel P. Glazer ◽  
Chunlei Zhang ◽  
J. Andries
Keyword(s):  
Large Scale ◽  
Fixed Bed ◽  
Calorific Value ◽  
Producer Gas ◽  
Fluidised Bed ◽  
Fuel Gas ◽  
Promising Alternative ◽  
Tar Cracking ◽  
Shift Reaction ◽  
Circulating Fluidised Bed

Energy generation from the use of biomass is gaining an increasing attention. Gasification of biomass at present, is widely accepted as a popular technical route to produce fuel gas for the application in boilers, engine, gas/micro turbine or fuel cell. Up to now, most of researchers have focused their attentions only on fixed-bed gasification and fluidised bed gasification under air-blown conditions. In that case, the producer gas is contaminated by high tar contents and particles which could lead to the corrosion and wear of blades of turbine. Furthermore, both the technologies, particularly fixed bed gasification, are not flexible for using multiple biomass-fuel types and also not feasible economically and environmentally for large scale application up to 10∼50 MWth. An innovative circulating fluidised bed concept has been considered in our laboratory for biomass gasification thereby overcoming these challenges. The concept combines and integrates partial oxidation, fast pyrolysis (with an instantaneous drying), gasification, and tar cracking, as well as a shift reaction, with the purpose of producing a high quality of gas, in terms of low tar level and particulates carried out in the producer gas, and overall emissions reduction associated with the combustion of producer gas. This paper describes our innovative concept and presents some experimental results. The results indicate that the gas yield can be above 1.80Nm3/kg with the calorific value of 4.5–5.0MJ/Nm3, and the fluctuation of the gas yield during the period of operation is 3.3%–3.5% for the temperature of 750–800 °C. In genera, the results achieved support our concept as a promising alternative for the gasifier coupled with micro/gas turbine to generate electricity.

Fluidised Bed Combustion of Blends of Coal and Pressed Sugar Beet Pulp

2011 ◽  
Author(s):  
John Ward ◽  
Muhammad Akram ◽  
Roy Garwood
Keyword(s):  
Sugar Beet ◽  
Alkali Metals ◽  
Combustion Process ◽  
Operating Conditions ◽  
Sugar Beet Pulp ◽  
Fluidised Bed ◽  
High Moisture ◽  
Wide Range ◽  
Beet Pulp ◽  
Blended Fuel

It can be difficult to burn relatively cheap, poor quality, unprepared biomass materials in industrial heating processes because of their variable composition, relatively low calorific values and high moisture contents. Consequently the stability and efficiency of the combustion process can be adversely affected unless they are co-fired with a hydrocarbon support fuel. There is a lack of information on the “optimum” conditions for co-firing of coal and high moisture biomass as well as on the proportions of support fuel which should be used. This paper is therefore concerned with the pilot scale (<25 kW thermal input) fluidised bed combustion of blends of coal with pressed sugar beet pulp, a solid biomass with an average moisture content of 71%. The experimental work was undertaken in collaboration with British Sugar plc who operate a coal-fired 40 MW thermal capacity fluidised bed producing hot combustion gases for subsequent drying applications. The project studied the combustion characteristics of different coal and pressed pulp blends over a wide range of operating conditions. It was found that stable combustion could only be maintained if the proportion of pulp by mass in the blended fuel was no greater than 50%. However evaporation of the moisture in the pressed pulp cools the bed so that the excess air which is necessary to maintain a specified bed temperature at a fixed thermal input can be reduced as the proportion of biomass in the blended fuel is increased. Therefore, with a 50/50 blend the bed can be operated with 20% less fluidising air and this will be beneficial for the output of the full scale plant since at present the flow rate of the air and hence the amount of coal which can be burnt is restricted by supply system pressure drop limitations. A further benefit of co-firing pressed pulp is that NOx emissions are reduced by about 25%. Agglomeration of the bed can be a problem when co-firing biomass because of the formation of “sticky” low melting point alkali metal silicate eutectics which result in subsequent adhesion of the ash and sand particles. Consequently longer term co-firing tests with a 50/50 blended fuel by mass were undertaken. Problems of bed agglomeration were not observed under these conditions with relatively low levels of alkali metals in the ash.

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