| 1. |
- Blasiak, Wlodzimierz, et al.
(författare)
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Evaluation of new combustion technologies for CO2 and NOX reduction in steel industries
- 2004
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Ingår i: AIR POLLUTION XII. - 1853127221 ; , s. 761-771
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Konferensbidrag (refereegranskat)abstract
- The paper presents state-of-the-art combustion technologies for heating applications in the steel industry. Two types of burners that exhibit dilution combustion were evaluated in this study carried out in a semi-industrial furnace. These were regenerative air-fuel burner and oxy-fuel burner. The tests with regenerative air-fuel were carried out applying operation both with and without oxygen-enrichment. The main parameters studied for the different types of burners and operations include heat flux, thermal efficiency, and NOX at different levels of in-leakage of air. The in-flame parameters were measured including temperature, gas composition, total and radiative heat fluxes. All the studied burners provide a high efficiency of fuel utilization, a large 'flame' with uniform temperature and heat flux profiles. The results also clearly indicate that NOX emissions can be maintained at low or even very low levels well (less than 100 mg/MJ of fuel) meeting the restrictions at industrial-scale operation.
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| 2. |
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| 3. |
- Yang, Weihong, et al.
(författare)
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Chemical flame length and volume in liquified propane gas combustion using high-temperature and low-oxygen-concentration oxidizer
- 2004
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Ingår i: Energy & Fuels. - : American Chemical Society (ACS). - 0887-0624 .- 1520-5029. ; 18:5, s. 1329-1335
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, the effect of a high-temperature oxidizer at different oxygen concentrations on chemical flame length and volume has been numerically studied. Liquified propane gas (LPG) was used as the fuel. Hot exhaust flue gas was used as the dilution gas. The studied parameters include oxygen concentration and temperature of the oxidizer, fuel temperature, fuel firing rate, and diameter of the fuel nozzle. The following results were obtained: (1) Chemical flame length increased as either the oxygen content decreased, the oxidizer temperature increased, or the fuel temperature decreased; furthermore, the chemical flame length was independent of the fuel flow rate and the diameter of the fuel nozzle for the studied cases. (2) Chemical flame volume increased either as the oxygen content decreased and the oxidizer temperature increased, the fuel temperature was reduced, or the fuel firing rate was increased; chemical flame volume was dependent very much on the oxygen concentration in the oxidizer. (3) Influences of high temperature and low oxygen concentration in the oxidizer on the flame Froude number (Fr-f) were examined; regimes of momentum control or buoyancy control were determined on the assumption that the oxidizer temperature and oxygen concentration are changeable. (4) A simple correlation of the chemical flame length and volume, relative to the flow parameters, has been derived in terms of a Frf number for momentum-buoyancy transition jet flame under the high-temperature air combustion (HiTAC) condition. The criteria constants of the dimensionless chemical flame volume (V-*) and the dimensionless chemical flame length (L-*), to assess the momentum- or buoyancy-controlled flame, are given.
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| 4. |
- Yang, Weihong, et al.
(författare)
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Combustion performance and numerical simulation of a high-temperature air-LPG flame on a regenerative burner
- 2004
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Ingår i: Scandinavian journal of metallurgy. - : Wiley. - 0371-0459 .- 1600-0692. ; 33:2, s. 113-120
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Tidskriftsartikel (refereegranskat)abstract
- High-temperature air combustion is attracting great interest in the metallurgical industry lately as its claimed benefits include large energy saving, low air emissions, increased product quality and increased productivity. This paper presents a numerical study of combustion performance in a semi-industrial test furnace equipped with a regenerative burner and with a conventional turbulent jet burner. The numerical calculation is also validated by experiment. In this regard, flow field was calculated with k-epsilon turbulence model, the model of combustion employed the eddy dissipation concept with a two-step mechanism to describe chemical reactions; radiation was handled using the discrete transfer method. The results indicate that equipping a furnace with high-cycle regenerative burner systems can provide more uniform gas temperature profiles, a higher energy utilizing efficiency, a low NOx emission, a larger flame, the low maximum local heat release and the possibility of low combustion noise.
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| 5. |
- Yang, Weihong, et al.
(författare)
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Length and volume in LPG flame using high-temperature and low oxygen oxidizer
- 2004
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Ingår i: International Symposium on Combustion, Abstracts of Works-in-Progress Posters.
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Konferensbidrag (refereegranskat)abstract
- The effect of a high temperature combustion oxidizer at different oxygen concentration on flame length and volume was numerically studied. LPG was used as the fuel. Flame length increased with either the decrease of oxygen content, or increase of oxidizer temperature, or decrease of fuel temperature. The flame length was independent of the fuel flow rate and the diameter of the fuel nozzle for studies cases. Flame volume increased either with the decrease of oxygen content and increase of oxidizer temperature, or with the reduction of fuel temperature, or with the increasing in fuel firing rate. Flame volume depended very much on the oxygen concentration in the oxidizer. This is an abstract of a paper presented at the 30th International Symposium on combustion (Chicago, IL 7/25-30/2004).
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