Increase of the Effective Energy from the Radiant Tube Equipped with Regenerative System in Comparison with Conventional Recuperative System
2005 (English)In: IFRF Combustion Journal, ISSN 1562-479X, no 03, 1-17 p.Article in journal (Refereed) Published
This paper presents the experimental results of High Temperature Air Combustion (HiTAC)investigations with the use of a radiant tube, in order to compare the Regenerative System (RS)with a conventional recuperative system.For this work a semi-industrial HiTAC test furnace was equipped with the W-shape RadiantTube. The working length of this tube was around 7,0 m and the diameter was 0,195 m. Theradiant tube was operated in sequence with a conventional recuperative system and aRegenerative System. The recuperative burner was mounted in the upper end of the tube. TheRS consisted of two burners, equipped with honeycomb ceramic regenerators, mounted to bothends of the radiant tube. The temperature profile of the tube wall was monitored by 74thermocouples located along the tube. Additional temperatures, flow rates and pressures weremeasured to assess and compare the energy balance of both systems. Pollutant emissions,including NOx and CO, as well as the exhaust gas composition were measured. The tests werecarried out over a wide range of parameters: firing power from 75 kW to 155 kW, furnacetemperature from 670°C to 950°C and an oxygen molar fraction in the exhaust gases set at 3%.LPG was used as a fuel in all tests.Test results show that the temperature profiles along the tube were more uniform when theregenerative system was used. The cross-sectional temperature distribution for the tube wasalso more uniform. Because of the relatively flat temperature distribution along the tube, moreenergy from the radiant tube can be emitted using RS in comparison with the conventionalrecuperative burner, for the same maximum temperatures of the tube. In certain conditions, theincrease of energy release can be up to 100%.Energy balance calculations show that the efficiency of the Regenerative System can be up to25% higher than that of the recuperative system, mainly due to very low temperature of fluegases for RS operation. Although, the preheated air temperature used for combustion wasmuch higher in the case of the regenerative system (in some tests as high as 960°C), the NOxemission was found to be almost the same in both cases.
Place, publisher, year, edition, pages
2005. no 03, 1-17 p.
High Temperature Air Combustion, Radiant Tube, Regenerative Burners
IdentifiersURN: urn:nbn:se:kth:diva-8882OAI: oai:DiVA.org:kth-8882DiVA: diva2:14358
QC 201010112005-12-062005-12-062010-10-11Bibliographically approved