Publication detail

Optimization of Secondary Air Distribution in Biomass Boiler by CFD Analysis

LISÝ, M. POSPÍŠIL, J. ŠTELCL, O. ŠPILÁČEK, M.

Czech title

Optimalizace distribuce sekundárního vzduchu do kotle na biomasu pomocí CFD analýzy

English title

Optimization of Secondary Air Distribution in Biomass Boiler by CFD Analysis

Type

journal article - other

Language

en

Original abstract

This paper deals with a use of CFD modelling for optimization of supply of secondary combustion air in the two-chamber biomass boiler combusting very wet biomass (capacity ca. 200 kW). Objective of the analysis is to observe the impact of a diameter of a secondary air supply pipe and air flow velocity on mixing of the secondary air with flue gas in the combustion chamber. The numerical model of the experimental boiler was built for subsequent utilization of CFD computation based on the finite element method. The commercial code STAR-CD was used for development of parametrical studies. Series of calculations were carried out for four different diameters of air distribution pipes and for three different air velocities in a distribution orifice. Quality of air dispersion in flue gas flow was assessed in the vertical cross section lead at the end of the combustion chamber. The results of calculation were verified on the experimental installation of the boiler. Influence of secondary air mixing on emission production was measured and analysed. Emissions of pollutants for recommended air distribution comply with emission limits stipulated in the most stringent class 5 according to ČSN-EN 303-5 as well as with emission limits under Regulation No. 405/2012 Sb.

Czech abstract

Tento článek se zabývá využívání CFD modelování pro optimalizaci dávkování sekundárního spalovacího vzduchu v dvoukomorovém kotli spalujícím velmi vlhkou biomasu (výkon cca. 200 kW). Cílem analýzy je sledovat vliv průměru přívodu sekundárního vzduchu a rychlosti proudění na míchání sekundárního vzduchu s prchavou hořlavinou ve spalovací komoře. Numerický model byl navržen pro následné využití CFD výpočtu založeného na metodě konečných prvků. Konkrétně byl použit program STAR-CD pro tvorbu parametrické studie. Série výpočtů byly provedeny pro čtyři různé průměry potrubí a tři různé vstupní rychlostíi distribuce sekundárního vzduchu. Kvalita promísení vzduchu a prchavé hořlaviny byla hodnocena ve svislém řezu na konci spalovací komory. Výsledky výpočtu byly ověřeny na experimentální jednotce. Byl sledován vliv parametrů sekundárního vzduchu na produkci emisí, které následně splnily jak limity nejpřísnější třídy 5. stanovené e ČSN EN 303-5, tak i emisní limity podle Nařízení č. 405/2012 Sb.

English abstract

This paper deals with a use of CFD modelling for optimization of supply of secondary combustion air in the two-chamber biomass boiler combusting very wet biomass (capacity ca. 200 kW). Objective of the analysis is to observe the impact of a diameter of a secondary air supply pipe and air flow velocity on mixing of the secondary air with flue gas in the combustion chamber. The numerical model of the experimental boiler was built for subsequent utilization of CFD computation based on the finite element method. The commercial code STAR-CD was used for development of parametrical studies. Series of calculations were carried out for four different diameters of air distribution pipes and for three different air velocities in a distribution orifice. Quality of air dispersion in flue gas flow was assessed in the vertical cross section lead at the end of the combustion chamber. The results of calculation were verified on the experimental installation of the boiler. Influence of secondary air mixing on emission production was measured and analysed. Emissions of pollutants for recommended air distribution comply with emission limits stipulated in the most stringent class 5 according to ČSN-EN 303-5 as well as with emission limits under Regulation No. 405/2012 Sb.

Keywords in Czech

CFD analýza, sekundární vzduch, proudění, míchání, koncentrace

Keywords in English

CFD analysis, secondary air, flow, mixing, concentration

Released

01.04.2016

Publisher

Trans Tech Publications, Switzerland

Location

Švýcarsko

ISSN

1662-7482

Volume

832

Number

1

Pages from–to

231–237

Pages count

7

BIBTEX


@article{BUT122916,
  author="Martin {Lisý} and Jiří {Pospíšil} and Otakar {Štelcl} and Michal {Špiláček},
  title="Optimization of Secondary Air Distribution in Biomass Boiler by CFD Analysis",
  year="2016",
  volume="832",
  number="1",
  month="April",
  pages="231--237",
  publisher="Trans Tech Publications, Switzerland",
  address="Švýcarsko",
  issn="1662-7482"
}