Application of Fluidization Reconstruction Energy-Saving Combustion Technology on 300MW CFB Boiler

2012 ◽  
Vol 516-517 ◽  
pp. 140-145 ◽  
Author(s):  
Jian Min Su ◽  
Nan Hu
Keyword(s):  
Energy Saving ◽  
Performance Improvement ◽  
Circulating Fluidized Bed ◽  
Heating Surface ◽  
Cfb Boiler ◽  
Auxiliary Power ◽  
Combustion Technology ◽  
High Power Consumption ◽  
Combustion Tests ◽  
Bed Material

Aiming at high power consumption by auxiliaries of circulating fluidized bed (CFB) boiler, combustion tests were carried out on a 300MW inferior anthracite fired CFB boiler to decrease the bed material inventory via energy saving combustion technologies for CFB boiler based on fluidization reconstruction. The effects of fluidization reconstruction on boiler performance improvement were analyzed. Application practices show that after fluidization reconstruction, the power consumed by auxiliaries of the CFB boiler decreases obviously. Auxiliary power ratio of the 300MW boiler unit has been reduced from 6.1% to 4.3%. The erosion of boiler heating surface has been alleviated obviously.

scholarly journals Development of Methane and Nitrous Oxide Emission Factors for the Biomass Fired Circulating Fluidized Bed Combustion Power Plant

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Chang-Sang Cho ◽  
Jae-Hwan Sa ◽  
Ki-Kyo Lim ◽  
Tae-Mi Youk ◽  
Seung-Jin Kim ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Fluidized Bed ◽  
Emission Factor ◽  
Circulating Fluidized Bed ◽  
Wood Chip ◽  
Emission Factors ◽  
Fluidized Bed Combustion ◽  
Cfb Boiler ◽  
Combustion Technology ◽  
The Subject

This study makes use of this distinction to analyze the exhaust gas concentration and fuel of the circulating fluidized bed (CFB) boiler that mainly uses wood biomass, and to develop the emission factors of Methane (CH4), Nitrous oxide (N2O). The fuels used as energy sources in the subject working sites are Wood Chip Fuel (WCF), RDF and Refused Plastic Fuel (RPF) of which heating values are 11.9 TJ/Gg, 17.1 TJ/Gg, and 31.2 TJ/Gg, respectively. The average concentrations of CH4and N2O were measured to be 2.78 ppm and 7.68 ppm, respectively. The analyzed values and data collected from the field survey were used to calculate the emission factor of CH4and N2O exhausted from the CFB boiler. As a result, the emission factors of CH4and N2O are 1.4 kg/TJ (0.9–1.9 kg/TJ) and 4.0 kg/TJ (2.9–5.3 kg/TJ) within a 95% confidence interval. Biomass combined with the combustion technology for the CFB boiler proved to be more effective in reducing the N2O emission, compared to the emission factor of the CFB boiler using fossil fuel.

A Study of Operation Performance of Circulating Fluidized Bed Combustion Boiler

2003 ◽  
Author(s):  
Zhengshun Wu ◽  
Hanping Chen ◽  
Dechang Liu ◽  
Jie Wang ◽  
Chuangzhi Wu ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Fluidized Bed Combustion ◽  
Operation Performance ◽  
Cfb Boiler ◽  
Bed Temperature ◽  
Suitable Temperature ◽  
Bed Material ◽  
Circulating Fluidized Bed Combustion

The operation performance of circulating fluidized bed combustion (CFBC) boiler was studied in this paper. The experimental results indicate that the load of CFB boiler has linear relation with bed temperature and bed material height of operation. By multiple regression analysis, the relation of the load of CFB boiler with bed temperature and bed material height of operation can be expressed as a formula. The suitable temperature and the bed material height corresponding to the load of CFB boiler can be found using the formula; the problem of the boiler to be blindly operated can be reduced in practice.

Co-Firing Coal, Biomass and Waste Fuels in Circulating Fluidized Bed Boilers to Reduce CO2 Emissions

2011 ◽  
Author(s):  
Ronald Hancharik
Keyword(s):  
Fluidized Bed ◽  
Co2 Emissions ◽  
Carbon Footprint ◽  
Circulating Fluidized Bed ◽  
Heating Surface ◽  
Energy Sources ◽  
Cfb Boiler ◽  
Design Considerations ◽  
Technical Challenges ◽  
Operating History

The combustion of CO2 neutral solid fuels like biomass and waste-based fuels with circulating fluidized bed (CFB) boiler designs has become an accepted way to generate electric power and process steam to reduce global CO2 emissions (i.e. reduce “carbon footprint”) and hence to reduce the potential impact on climate change. In the European Union, for example, there is a co-combustion directive to encourage the use of biomass and waste as energy sources with the co-firing of coal. Quite often biomass and waste combustion in CFB’s have unique technical challenges when compared to fossil fuels. The technical challenges of firing these CO2 neutral fuels do impact CFB boiler design and may impact plant lifecycle and reliability when compared to coal. Among these are combustion bed agglomeration, furnace and heating surface slagging, and new forms of corrosion potential. However, when co-firing these CO2 neutral fuels with coal, these challenges can be tempered in a positive way through inherent changes in the flue gas chemistry and other design considerations. Co-firing makes sense. In addition to reducing the carbon footprint of a boiler project through use of biomass and waste, these energy sources can have a significant positive impact on plant financials owing to low cost supply. However these fuels can have wide variations in availability and energy content over the course of the many years of a boiler’s life. As such, maintaining coal as a supplemental fuel or back-up fuel also provides significant benefit in terms of guaranteeing the energy input supply and thereby securing plant availability. This benefit can help lower project financial risk and improve financial attractiveness and viability. This paper describes this type of boiler, its design considerations and operating history. Highlighted herein is the operating facility in Pori, Finland, commissioned in 2008, which is a 60 MWe CFB boiler burning peat, biomass and recycled waste fuel (RDF) with coal as a back-up fuel. Other facilities with similar design and with operating history of over 10 years are included as reference.

The Exploration and Practice of Using Additive to Inhibit the Heating Surface Deposition in Biomass-Fired Boiler

2012 ◽  
Vol 608-609 ◽  
pp. 411-418
Author(s):  
Fang Huang ◽  
Chun Jiang Yu ◽  
Qin Hui Wang ◽  
Meng Xiang Fang ◽  
Zhong Yang Luo
Keyword(s):  
Circulating Fluidized Bed ◽  
Heating Surface ◽  
Fine Powder ◽  
X Ray Diffraction ◽  
Surface Deposition ◽  
Cfb Boiler ◽  
X Ray ◽  
Inhibition Effect ◽  
Industrial Boiler ◽  
Deposition Sample

In response to the deposition problem in biomass-fired boiler, inert addictive was tested to inhibit the possibility of coking. The deposition samples collected from final and primary superheater of biomass-fired CFB (circulating fluidized bed) boiler were grinded into fine powder. The inhibitive ability of additive was tested by mixing the deposition sample with different proportions of inhibitor under high temperature. By means of scanning electron microscope (SEM), X-ray diffraction (XRD) and other analytical procedures, the properties of the samples with inhibitor such as microstructure, composition were studied. The inhibitor was also introduced to the industrial biomass CFB boiler to verify its inhibition effect on superheater deposition. Unfortunately, the effect of adding inhibitor in industrial boiler is not certain, though the inhibitor added to the samples is obviously effective in weakening coking in the laboratory scope.

scholarly journals Fluidized bed combustion with the use of Greek solid fuels

2003 ◽  
Vol 7 (2) ◽  
pp. 33-42
Author(s):  
Emmanuel Kakaras ◽  
Panagiotis Grammelis ◽  
George Skodras ◽  
Panagiotis Vourliotis
Keyword(s):  
Fluidized Bed ◽  
Brown Coal ◽  
Circulating Fluidized Bed ◽  
Pilot Scale ◽  
Thermal Capacity ◽  
Low Rank ◽  
Fluidized Bed Combustion ◽  
Bubbling Fluidized Bed ◽  
Combustion Technology ◽  
Combustion Tests

The paper is an overview of the results obtained up to date from the combustion and co-combustion activities with Greek brown coal in different installations, both in semi-industrial and laboratory scale. Combustion tests with Greek lignite were realized in three different Circulating Fluidized Bed Combustion (CFBC) facilities. Low rank lignite was burned in a pilot scale facility of approx. 100kW thermal capacity, located in Athens (NTUA) and a semi-industrial scale of 1.2 MW thermal capacity, located at RWE's power station Niederaussem in Germany. Co-combustion tests with Greek xylitic lignite and waste wood were carried out in the 1 MWth CFBC installation of AE&E, in Austria. Lab-scale co-combustion tests of Greek pre-dried lignite with biomass were accomplished in a bubbling fluidized bed in order to investigate ash melting problems. The obtained results of all aforementioned activities showed that fluidized bed is the appropriate combustion technology to efficiently exploit the low quality Greek brown coal either alone or in conjunction with biomass species.

Study on the Contamination Coefficient of Convective Heating Surface in a Circulating Fluidized Bed Boiler

2013 ◽  
Vol 732-733 ◽  
pp. 286-290
Author(s):  
Yu Zhao Wang ◽  
Xue Min Liu ◽  
Ai Cheng Liu ◽  
Qing Liu ◽  
Jian Chun Zhang ◽  
...  
Keyword(s):  
Circulating Fluidized Bed ◽  
Collection Efficiency ◽  
Heating Surface ◽  
Surface Contamination ◽  
Convective Heating ◽  
Exhaust Gas ◽  
Gas Temperature ◽  
Gas Velocity ◽  
Cfb Boiler ◽  
Exhaust Gas Temperature

The ash deposition and the gas velocity affect the exhaust gas temperature of a CFB boiler. The surface contamination in a CFB boiler is quite different from that one in the pulverized coal boiler. It is suggested that the surface contamination in a CFB boiler should be determined according to the ash content in the fuel as well as the cyclone collection efficiency. The effect of the gas velocity on the surface contamination is very important. The lower gas velocity causes more serious contamination, leading to the higher exhaust gas temperature. The staged tube arrangement should be employed. And the gas velocity should be designed higher to enhance the self-cleaning ability. Anyway, the soot blower should be designed in the CFB boiler convective heating surface. The ratio of the practical contamination coefficient to the design one, k,is the strong function of gas velocity, wy, which was expressed as: k=1+exp(6.8-wy)

Operational Performance and Optimization of a 465t/h CFB Boiler in China

2005 ◽  
Author(s):  
Xinmu Zhao ◽  
Junfu Lu ◽  
Jianhua Yang ◽  
Qingguo Zhang ◽  
Fengliang Dong ◽  
...  
Keyword(s):  
Circulating Fluidized Bed ◽  
Bottom Ash ◽  
Heating Surface ◽  
Gas Temperature ◽  
Fuel Gas ◽  
Future Design ◽  
Bed Temperature ◽  
The Future ◽  
And Performance ◽  
Bed Material

In the last three years in China, more than 80 units of 135MWe circulating fluidized bed (CFB) boilers were ordered, and about two dozens of them have been put into operation. So far, the experience and performance evaluation of the boilers with such large capacity are very limited. A series of cold and hot tests were carried out on the boiler in order to optimize the operation and provide more information to the future design. The influence of coal properties, bed material fluidization, air distribution, bed temperature and pressure drop on the boiler performance such as carbon content in fly ash was assessed and discussed. Some problems of the boiler, including the bottom ash system, milling system, abrasion of the heating surface in the furnace, refractory stability, and exhaust fuel gas temperature are reported and suggestions are given for the future improvement and design.

Pilot-scale combustion studies with kraft lignin in a powder burner and a CFB boiler

TAPPI Journal ◽  
2010 ◽  
Vol 9 (6) ◽  
pp. 24-30 ◽  
Author(s):  
NIKLAS BERGLIN ◽  
PER TOMANI ◽  
HASSAN SALMAN ◽  
SOLVIE HERSTAD SVÄRD ◽  
LARS-ERIK ÅMAND
Keyword(s):  
Circulating Fluidized Bed ◽  
Black Liquor ◽  
Chloride Content ◽  
Pilot Scale ◽  
High Energy ◽  
Kraft Lignin ◽  
High Energy Density ◽  
Alkali Chloride ◽  
Cfb Boiler ◽  
Solid Biofuel

Processes have been developed to produce a solid biofuel with high energy density and low ash content from kraft lignin precipitated from black liquor. Pilot-scale tests of the lignin biofuel were carried out with a 150 kW powder burner and a 12 MW circulating fluidized bed (CFB) boiler. Lignin powder could be fired in a powder burner with good combustion performance after some trimming of the air flows to reduce swirl. Lignin dried to 10% moisture content was easy to feed smoothly and had less bridging tendencies in the feeding system than did wood/bark powder. In the CFB boiler, lignin was easily handled and cofired together with bark. Although the filter cake was broken into smaller pieces and fines, the combustion was not disturbed. When cofiring lignin with bark, the sulfur emission increased compared with bark firing only, but most of the sulfur was captured by calcium in the bark ash. Conventional sulfur capture also occurred with addition of limestone to the bed. The sulfur content in the lignin had a significantly positive effect on reducing the alkali chloride content in the deposits, thus reducing the high temperature corrosion risk.

scholarly journals Investigation of Ash Deposition Dynamic Process in an Industrial Biomass CFB Boiler Burning High-Alkali and Low-Chlorine Fuel

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1092
Author(s):  
Hengli Zhang ◽  
Chunjiang Yu ◽  
Zhongyang Luo ◽  
Yu’an Li
Keyword(s):  
Gas Flow ◽  
Circulating Fluidized Bed ◽  
Deposition Process ◽  
Biomass Combustion ◽  
Ash Deposition ◽  
Biomass Ash ◽  
Cfb Boiler ◽  
Third Stage ◽  
Ash Deposit ◽  
High Alkali

The circulating fluidized bed (CFB) boiler is a mainstream technology of biomass combustion generation in China. The high flue gas flow rate and relatively low combustion temperature of CFB make the deposition process different from that of a grate furnace. The dynamic deposition process of biomass ash needs further research, especially in industrial CFB boilers. In this study, a temperature-controlled ash deposit probe was used to sample the deposits in a 12 MW CFB boiler. Through the analysis of multiple deposit samples with different deposition times, the changes in micromorphology and chemical composition of the deposits in each deposition stage can be observed more distinctively. The initial deposits mainly consist of particles smaller than 2 μm, caused by thermophoretic deposition. The second stage is the condensation of alkali metal. Different from the condensation of KCl reported by most previous literatures, KOH is found in deposits in place of KCl. Then, it reacts with SO2, O2 and H2O to form K2SO4. In the third stage, the higher outer layer temperature of deposits reduces the condensation rate of KOH significantly. Meanwhile, the rougher surface of deposits allowed more calcium salts in fly ash to deposit through inertial impact. Thus, the elemental composition of deposits surface shows an overall trend of K decreasing and Ca increasing.

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.

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