Ignition delay of syngas is an important factor that affects stable operation of combustor and adding diluents to syngas can reduce NO_x emission.This paper used H_2O,CO_2 and N_2 as diluents and calculated ignition d...Ignition delay of syngas is an important factor that affects stable operation of combustor and adding diluents to syngas can reduce NO_x emission.This paper used H_2O,CO_2 and N_2 as diluents and calculated ignition delay of syngas in temperature range of 900-1400 K and at pressures of 10 and 30 atm respectively.In high temperature range,comparing with N_2 dilution,adding H_2O and CO_2 can significantly inhibit autoignition of syngas because they have higher collision efficiencies in reaction H + O_2(+ M) = HO_2(+ M).As for low temperature conditions,adding H_2O can increase reactivity of syngas,especially under high pressure,because of its high collision efficiency in reaction H_2O_2(+ M) = 2OH(+ M).Comparing with different dilution rates shows that for syngas and operating conditions in this paper,adding N_2 mainly influences temperature rising process of syngas combustion,thus inhibiting reactivity of syngas.In addition,this paper calculated ignition delay of syngas at different equivalence ratios(φ= 0.5,1.0).Higher equivalence ratio(φ≤1) means that less air(especially N_2) needs to be heated,thus promoting ignition of syngas,展开更多
The development of integrated gasification combined cycle （IGCC） systems provides cost-effective and environmentally sound options for meeting the future coal-utilizing power generation needs in the worht. The combu...The development of integrated gasification combined cycle （IGCC） systems provides cost-effective and environmentally sound options for meeting the future coal-utilizing power generation needs in the worht. The combustion of gasified coal fuel significantly influences overall performance of IGCC power generation. Experi- ments are performed to investigate the characteristics of syngas swirling flame using the particle image velocimetry （PIV） in this paper. With the increase of CO/H2 molar ratio, the distance between the nozzle and the fuel vortex in flame increases at first, and then reduces slowly; maximum of the axial mean velocity increases continuously, but the axial mean velocity peaks on the side of centerline change little. The experiment indicates that with the increase of fuel to air velocity ratio, the fuel vortex grows up at first, and then becomes thinner; the distance from the fuel vortex to the nozzle reduces at first, and then increases; inner boundary of the recirculating zone increases. Furthermore, difference between the methane swirling flow field and the syngas swirling one is analyzed in this paper. It can establish the benchmarks for the development and validation of combustion numerical simulation by the data from this experiment.展开更多
基金Supported by National High Technology Research and Development Program of China(2009AA05Z310)
文摘Ignition delay of syngas is an important factor that affects stable operation of combustor and adding diluents to syngas can reduce NO_x emission.This paper used H_2O,CO_2 and N_2 as diluents and calculated ignition delay of syngas in temperature range of 900-1400 K and at pressures of 10 and 30 atm respectively.In high temperature range,comparing with N_2 dilution,adding H_2O and CO_2 can significantly inhibit autoignition of syngas because they have higher collision efficiencies in reaction H + O_2(+ M) = HO_2(+ M).As for low temperature conditions,adding H_2O can increase reactivity of syngas,especially under high pressure,because of its high collision efficiency in reaction H_2O_2(+ M) = 2OH(+ M).Comparing with different dilution rates shows that for syngas and operating conditions in this paper,adding N_2 mainly influences temperature rising process of syngas combustion,thus inhibiting reactivity of syngas.In addition,this paper calculated ignition delay of syngas at different equivalence ratios(φ= 0.5,1.0).Higher equivalence ratio(φ≤1) means that less air(especially N_2) needs to be heated,thus promoting ignition of syngas,
基金the National Basic Research Program (973) of China(No.2007CB210102)
文摘The development of integrated gasification combined cycle （IGCC） systems provides cost-effective and environmentally sound options for meeting the future coal-utilizing power generation needs in the worht. The combustion of gasified coal fuel significantly influences overall performance of IGCC power generation. Experi- ments are performed to investigate the characteristics of syngas swirling flame using the particle image velocimetry （PIV） in this paper. With the increase of CO/H2 molar ratio, the distance between the nozzle and the fuel vortex in flame increases at first, and then reduces slowly; maximum of the axial mean velocity increases continuously, but the axial mean velocity peaks on the side of centerline change little. The experiment indicates that with the increase of fuel to air velocity ratio, the fuel vortex grows up at first, and then becomes thinner; the distance from the fuel vortex to the nozzle reduces at first, and then increases; inner boundary of the recirculating zone increases. Furthermore, difference between the methane swirling flow field and the syngas swirling one is analyzed in this paper. It can establish the benchmarks for the development and validation of combustion numerical simulation by the data from this experiment.
