Benoît Taupin - Academia.edu (original) (raw)

Papers by Benoît Taupin

Fuel, 2009

Co-firing of biomass with pulverised coal at existing coal power stations remains a practical opt... more Co-firing of biomass with pulverised coal at existing coal power stations remains a practical option available to power plant operators and is being widely adopted as one of the main technologies for reducing greenhouse gas emissions. However, there is a range of technological problems that are not well understood. This paper presents experimental investigations into the co-firing of pulverised coal directly comilled with 5-20% biomass on a 3 MWth Combustion Test Facility. A number of combustion parameters, including flame temperature and oscillation frequency and particle size distribution, were measured under a range of co-firing conditions. The gas species within the flame and fly ash in flue gas were also sampled and analysed. The experimental data collected are used to study the impact of biomass additions to pulverised coal on the combustion characteristics of the co-firing process. The relationships between the flame characteristics, gas species and ash deposition of the furnace are investigated. The results suggest that, due to the varying physical and chemical properties of the biomass fuels, the biomass additions have impact on the combustion characteristics in a very complicated way. It has been found that the biomass addition to coal would improve the combustion efficiency because of the lower CO concentrations and higher char burnout level in co-firing. In addition, NO x emission has been found closely linked to the flame stability, and SO x emission reduced in general for all co-firing cases.

Ex perimental investigation into the co-firing of pulverised coal with biomass on a 3MW th Combus... more Ex perimental investigation into the co-firing of pulverised coal with biomass on a 3MW th Combustion Test Facility has been conducted. A variety of combustion parameters including flame temperature, gas species within the flame and fly ash in flue gas, were measured using flame imaging and gas/ash sampling techniques under a range of co-firing conditions. The results suggest that, due to the varying physical and chemical properties of the biomass, the biomass additions have impact on the combustion characteris tics such as increased temperature, improved flame stability and higher level of char burnout.

The purpose of this experimental study is to identify the factors that give rise to combustion in... more The purpose of this experimental study is to identify the factors that give rise to combustion instability in case of lean premixed combustion. The studied experimental device is gas turbine combustor, where the flame is stabilized in the dump combustor with a swirling and bluff-body injector. This combustor is optically accessible. A parametrical study has been conducted in the way to provide information on the effect of the equivalence ratio, φ, while the mean inlet velocity remains constant. LDV and OH * chemiluminescence measurements were performed in the reacting flows for a 50° swirler and for different equivalence ratio conditions. LDV measurements show that two distinct recirculations zones appears in the resulting flow. One is formed in the corner due to the sudden-expansion, while the other one is due to the swirling motion of the incoming flow. In order to obtain the 2D mean reaction location, an Abel deconvolution algorithm is applied to the average of 200 OH* chemiluminescence images. It allows to enhance the following relationships: as the premixing becomes leaner, the flame takes different locations in the flow. For φ > 0.7, the flame is in a steady state, anchored near the bluff-body between the two recirculation zones. For 0.7 > φ > 0.65, an extension of reaction zone occurs in the corner recirculation zone and downstream near the quartz tube. For 0.65 > φ > 0.6, the flame becomes unsteady and an oscillation of the OH * emission intensity occurs with the same frequency as measured by dynamic pressure in the combustion chamber (≈16 Hz). For φ = 0.57, the flame becomes stable again without any reaction in the corner recirculation zone. When φ is more reduced (φ <0.57), the blow-out occurs. In order to characterize the unsteady state, CH * visualization is realized by triggering acquisition with the temporal signal of pressure. Results shows a periodic behavior of flame position and combustion intensity. The analysis of all results shows a coupling between the cyclic phenomenon of vortex shedding and fluctuations in gas supply inducing a cyclic equivalence ratio at the inlet.

Experimental Thermal and Fluid Science, 2004

Cylindrical combustion chambers, 1:7 model scale of a dry low NO x combustor devoted to 200 kW el... more Cylindrical combustion chambers, 1:7 model scale of a dry low NO x combustor devoted to 200 kW elec cogeneration plants, have been developed in order to understand instability phenomenon in lean premixed combustion occurring in low NO x gas turbine (LNGT). Dynamic measurements of chamber pressure and of CH Ã emissions have been performed. CH Ã emission images have also been measured. Spectrum with several frequencies have been observed. Frequencies which are common to pressure spectrum and CH Ã emission spectrum are considered to be characteristic of combustion phenomenon. The magnitude of the 32 Hz low frequency increase abruptly when mixture ratio is decreased to values close to extinction, and CO emissions show the same behaviour. For high equivalence ratios, the magnitude of 133 Hz peak strongly increases while the magnitude of 530 Hz peak decreases. The effect of the injection position of primary dilution air has been studied. It is observed that primary dilution decreases flame size, and has an effect on the flame structure, on local combustion equivalence ratio, which induce effects on flame stability and on CO emissions.

Fuel, 2009

Co-firing of biomass with pulverised coal at existing coal power stations remains a practical opt... more Co-firing of biomass with pulverised coal at existing coal power stations remains a practical option available to power plant operators and is being widely adopted as one of the main technologies for reducing greenhouse gas emissions. However, there is a range of technological problems that are not well understood. This paper presents experimental investigations into the co-firing of pulverised coal directly comilled with 5-20% biomass on a 3 MWth Combustion Test Facility. A number of combustion parameters, including flame temperature and oscillation frequency and particle size distribution, were measured under a range of co-firing conditions. The gas species within the flame and fly ash in flue gas were also sampled and analysed. The experimental data collected are used to study the impact of biomass additions to pulverised coal on the combustion characteristics of the co-firing process. The relationships between the flame characteristics, gas species and ash deposition of the furnace are investigated. The results suggest that, due to the varying physical and chemical properties of the biomass fuels, the biomass additions have impact on the combustion characteristics in a very complicated way. It has been found that the biomass addition to coal would improve the combustion efficiency because of the lower CO concentrations and higher char burnout level in co-firing. In addition, NO x emission has been found closely linked to the flame stability, and SO x emission reduced in general for all co-firing cases.

Ex perimental investigation into the co-firing of pulverised coal with biomass on a 3MW th Combus... more Ex perimental investigation into the co-firing of pulverised coal with biomass on a 3MW th Combustion Test Facility has been conducted. A variety of combustion parameters including flame temperature, gas species within the flame and fly ash in flue gas, were measured using flame imaging and gas/ash sampling techniques under a range of co-firing conditions. The results suggest that, due to the varying physical and chemical properties of the biomass, the biomass additions have impact on the combustion characteris tics such as increased temperature, improved flame stability and higher level of char burnout.

The purpose of this experimental study is to identify the factors that give rise to combustion in... more The purpose of this experimental study is to identify the factors that give rise to combustion instability in case of lean premixed combustion. The studied experimental device is gas turbine combustor, where the flame is stabilized in the dump combustor with a swirling and bluff-body injector. This combustor is optically accessible. A parametrical study has been conducted in the way to provide information on the effect of the equivalence ratio, φ, while the mean inlet velocity remains constant. LDV and OH * chemiluminescence measurements were performed in the reacting flows for a 50° swirler and for different equivalence ratio conditions. LDV measurements show that two distinct recirculations zones appears in the resulting flow. One is formed in the corner due to the sudden-expansion, while the other one is due to the swirling motion of the incoming flow. In order to obtain the 2D mean reaction location, an Abel deconvolution algorithm is applied to the average of 200 OH* chemiluminescence images. It allows to enhance the following relationships: as the premixing becomes leaner, the flame takes different locations in the flow. For φ > 0.7, the flame is in a steady state, anchored near the bluff-body between the two recirculation zones. For 0.7 > φ > 0.65, an extension of reaction zone occurs in the corner recirculation zone and downstream near the quartz tube. For 0.65 > φ > 0.6, the flame becomes unsteady and an oscillation of the OH * emission intensity occurs with the same frequency as measured by dynamic pressure in the combustion chamber (≈16 Hz). For φ = 0.57, the flame becomes stable again without any reaction in the corner recirculation zone. When φ is more reduced (φ <0.57), the blow-out occurs. In order to characterize the unsteady state, CH * visualization is realized by triggering acquisition with the temporal signal of pressure. Results shows a periodic behavior of flame position and combustion intensity. The analysis of all results shows a coupling between the cyclic phenomenon of vortex shedding and fluctuations in gas supply inducing a cyclic equivalence ratio at the inlet.

Experimental Thermal and Fluid Science, 2004

Cylindrical combustion chambers, 1:7 model scale of a dry low NO x combustor devoted to 200 kW el... more Cylindrical combustion chambers, 1:7 model scale of a dry low NO x combustor devoted to 200 kW elec cogeneration plants, have been developed in order to understand instability phenomenon in lean premixed combustion occurring in low NO x gas turbine (LNGT). Dynamic measurements of chamber pressure and of CH Ã emissions have been performed. CH Ã emission images have also been measured. Spectrum with several frequencies have been observed. Frequencies which are common to pressure spectrum and CH Ã emission spectrum are considered to be characteristic of combustion phenomenon. The magnitude of the 32 Hz low frequency increase abruptly when mixture ratio is decreased to values close to extinction, and CO emissions show the same behaviour. For high equivalence ratios, the magnitude of 133 Hz peak strongly increases while the magnitude of 530 Hz peak decreases. The effect of the injection position of primary dilution air has been studied. It is observed that primary dilution decreases flame size, and has an effect on the flame structure, on local combustion equivalence ratio, which induce effects on flame stability and on CO emissions.