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Sefidari, Hamid
Publications (5 of 5) Show all publications
Razmjoo, N., Sefidari, H. & Strand, M. (2016). Measurements of temperature and gas composition within the burning bed of wet woody residues in a 4 MW moving grate boiler. Fuel processing technology, 152, 438-445
Open this publication in new window or tab >>Measurements of temperature and gas composition within the burning bed of wet woody residues in a 4 MW moving grate boiler
2016 (English)In: Fuel processing technology, ISSN 0378-3820, E-ISSN 1873-7188, Vol. 152, p. 438-445Article in journal (Refereed) Published
Abstract [en]

Moving grate firing systems are widely used for biomass combustion. The characteristics of the fuel bed combustion in moving grate boilers are of practical interest as they are directly related to the release of pollutants and affect the furnace efficiency. Measurements of temperature and gas species concentrations inside the fuel bed are necessary to improve our understanding of the highly complex processes involved in biomass combustion.There have been few experimental studies of the fuel bed of industrial scale grate furnaces. The present study measured temperature and gas species concentrations within a thick burning bed of wet woody biomass, in a  4 MW reciprocating grate boiler. Measurements were carried out under three different operating conditions through ports located in the wall of the furnace using a stainless steel probe incorporating a thermocouple. Temperatures of about 1000 °C were measured close to the grate, indicating intense combustion at the bottom of the fuel bed. The temperature distribution along the bed height showed that different stages of the combustion process take place in horizontally adjacent layers along the grate. Higher flow rates of the primary air resulted in relatively higher CO and lower CO2 and NO concentrations in the fuel bed.

Place, publisher, year, edition, pages
Elsevier, 2016
Keywords
Combustion
National Category
Energy Engineering
Research subject
Technology (byts ev till Engineering), Bioenergy Technology
Identifiers
urn:nbn:se:lnu:diva-55137 (URN)10.1016/j.fuproc.2016.07.011 (DOI)000381950200050 ()2-s2.0-84979696737 (Scopus ID)
Available from: 2016-08-08 Created: 2016-08-08 Last updated: 2017-05-29Bibliographically approved
Razmjoo, N., Sefidari, H. & Strand, M. (2015). Experimental investigation of fuel bed combustion in an industrial grate boiler. In: : . Paper presented at 10th European Conference on Industrial Furances and Boilers, April 7-10, 2015, Porto. Portugal
Open this publication in new window or tab >>Experimental investigation of fuel bed combustion in an industrial grate boiler
2015 (English)Conference paper, Published paper (Refereed)
Abstract [en]

Information about distributions of temperature and gas species within the fuel bed is of great importance in studying the formation of pollutants in an industrial-scale biomass boiler. The main objective of this study was to investigate the gas composition and temperature in some available sections of the fuel bed of a 4 MW reciprocating grate boiler. The results showed that the temperature profiles of the grate bars and the fuel bed suggest significant temperature gradients versus the height of the fuel bed. The averaged NO, CO, CO2, and O2 concentrations measured in the fuel bed were about 80 ppm, 21, 11 and 1 vol. %, respectively.

Place, publisher, year, edition, pages
Portugal: , 2015
Keywords
Biomass; Grate combustion; Fuel bed; Experimental; Temperature; Gas concentration
National Category
Engineering and Technology
Research subject
Technology (byts ev till Engineering), Bioenergy Technology
Identifiers
urn:nbn:se:lnu:diva-42273 (URN)
Conference
10th European Conference on Industrial Furances and Boilers, April 7-10, 2015, Porto
Available from: 2015-04-14 Created: 2015-04-14 Last updated: 2016-05-03Bibliographically approved
Sefidari, H., Razmjoo, N. & Strand, M. (2014). An experimental study of combustion and emissions of two types of woody biomass in a 12-MW reciprocating-grate boiler. Fuel, 135, 120-129
Open this publication in new window or tab >>An experimental study of combustion and emissions of two types of woody biomass in a 12-MW reciprocating-grate boiler
2014 (English)In: Fuel, ISSN 0016-2361, E-ISSN 1873-7153, Vol. 135, p. 120-129Article in journal (Refereed) Published
Abstract [en]

The gaseous emissions of primary concern from biomass combustion are nitrogen oxides (NOX), carbon monoxide, and various unburned gaseous components. Detailed characterization of the gas in the hot reaction zones is necessary to study the release, formation, and evolution of the gas components. In the present study, gas temperature and concentration were measured in a 12-MWth biomass-fired reciprocating-grate boiler operated with over-fire air and flue-gas recirculation. Temperature measurement was combined with flue gas quenching and sample gas extraction using two water-cooled stainless-steel suction pyrometers. The concentration profiles of O2, NO, and CO were experimentally determined throughout the furnace, and the profile gas temperature was measured in several positions inside the furnace for the two types of woody biomass studied. For both fuels, the gas temperature varied between approximately 450 °C (average primary chamber temperature) and 1200 °C (average secondary chamber temperature). The concentration profiles of CO and O2 suggested no conclusive difference between the two types of biomass. However, the local mean concentrations of NO and NOX emission factors (measured in the stack) were higher for Greenery fuel due to its higher nitrogen content than that of Standard fuel.

Place, publisher, year, edition, pages
Elsevier, 2014
Keywords
Combustion
National Category
Energy Engineering
Research subject
Technology (byts ev till Engineering), Bioenergy Technology
Identifiers
urn:nbn:se:lnu:diva-36117 (URN)10.1016/j.fuel.2014.06.051 (DOI)000340945400017 ()2-s2.0-84904193435 (Scopus ID)
Available from: 2014-07-17 Created: 2014-07-17 Last updated: 2017-12-05Bibliographically approved
Razmjoo, N., Sefidari, H. & Strand, M. (2014). Characterization of hot gas in a 4 MW reciprocating grate boiler. Fuel processing technology, 124, 21-27
Open this publication in new window or tab >>Characterization of hot gas in a 4 MW reciprocating grate boiler
2014 (English)In: Fuel processing technology, ISSN 0378-3820, E-ISSN 1873-7188, Vol. 124, p. 21-27Article in journal (Refereed) Published
Abstract [en]

The gas concentration and temperature information from the combustion of biomass offer significant advantages to enhance the understanding of an industrial-scale biomass heating plant. The main objective of this study was to investigate the gas composition and temperature in a 4 MW reciprocating grate boiler. An extensive series of measurements was carried out, and the samples, which were drawn through different ports by means of a water-cooled stainless steel suction pyrometer, were analyzed for temperature and for O2, CO, and NO concentrations. The results showed that the averaged NO, CO, and O2 concentrations in the gas phase during fuel combustion in the primary chamber were 40 ppm, 3.5 and 6.5 vol.%, respectively, while the values were 80 ppm, 1.1 and 6 vol.% in the secondary chamber. Detailed gas species and temperature distributions are discussed, which provide good possibilities for the control of emissions.

Place, publisher, year, edition, pages
Elsevier, 2014
Keywords
Combustion
National Category
Energy Engineering
Research subject
Technology (byts ev till Engineering), Bioenergy Technology
Identifiers
urn:nbn:se:lnu:diva-32675 (URN)10.1016/j.fuproc.2014.02.011 (DOI)000336879800003 ()2-s2.0-84896797704 (Scopus ID)
Available from: 2014-03-07 Created: 2014-03-07 Last updated: 2017-12-05Bibliographically approved
Razmjoo, N., Sefidari, H., Strand, M. & Yang, J. (2013). Gas measurements and characterization of wood combustion in a traveling grate boiler. In: Proceedings for 21st European Biomass Conference and Exhibition: . Paper presented at 21st European Biomass Conference and Exhibition, Copenhagen, Danmark, 3rd-7th June, 2013 (pp. 591-594). ETA-Florence Renewable Energies
Open this publication in new window or tab >>Gas measurements and characterization of wood combustion in a traveling grate boiler
2013 (English)In: Proceedings for 21st European Biomass Conference and Exhibition, ETA-Florence Renewable Energies , 2013, p. 591-594Conference paper, Published paper (Refereed)
Abstract [en]

Experimental tests have been carried out on a moving grate boiler at a 4 MW heating plant located at a sawing mill in south of Sweden. In order to investigate the performance of the combustion chamber, the local concentrations of O2, NO and CO are determined in the region above the grate using two water-cooled stainless steel probes of different lengths and diameters. The fuel used was sawmill waste consisting of bark, sawdust and shavings. The results of the study provided valuable insights into the combustion process.

Place, publisher, year, edition, pages
ETA-Florence Renewable Energies, 2013
Series
European Biomass Conference and Exhibition Proceedings, ISSN 2282-5819
Keywords
combustion
National Category
Chemical Engineering
Research subject
Technology (byts ev till Engineering), Bioenergy Technology
Identifiers
urn:nbn:se:lnu:diva-26905 (URN)10.5071/21stEUBCE2013-2CO.7.5 (DOI)978-88-89407-53-0 (ISBN)
Conference
21st European Biomass Conference and Exhibition, Copenhagen, Danmark, 3rd-7th June, 2013
Note

artikeln kommer kanske att finnas på sidan http://www.etaflorence.it/proceedings/

Available from: 2013-06-20 Created: 2013-06-20 Last updated: 2015-05-27Bibliographically approved
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