In addition to the matured ＂Laser Inertial Fusion Energy （LIFE）＂ with spherical compression of deuterium-tritium （DI） for a pure fusion engine or for fusion-fission-hybrid operation, a very new scheme may have n...In addition to the matured ＂Laser Inertial Fusion Energy （LIFE）＂ with spherical compression of deuterium-tritium （DI） for a pure fusion engine or for fusion-fission-hybrid operation, a very new scheme may have now been opened by igniting the neutron-free reaction of proton-boron-11 （p-^11B） using side-on block ignition. Laser pulses of several petawatt power and ps duration led to thc discovery of an anomaly of interaction, if the prepulses are cut off by a factor 108 （contrast ratio） to avoid relativistic self focusing. In this case the Bobin-Chu conditions of side-on ignition of solid fusion fuel can be applied after several improvements leading to energy gains of 10,000 similar to the Nuckolls-Wood ignition with extremely intense 5 MeV electron beams. In contrast to the impossible laser-ignition of p-^11B by the usual spherical compression, the side-on ignition is less than ten times only more difficult of DT ignition. This p-^11B fusion produces less radioactivity per gained energy than burning coal. After encouraging success with computations based on the different nuclear cross sections, next steps are focusing on stability and transport problems.展开更多
In order to achieve the target of reducing oil consumption to zero for pulverized coal(PC)boiler in power plant,the paper developed a novel coal pulverized ignition approach,called as Alternating-Current plasma(AC pla...In order to achieve the target of reducing oil consumption to zero for pulverized coal(PC)boiler in power plant,the paper developed a novel coal pulverized ignition approach,called as Alternating-Current plasma(AC plasma)ignition,with the advantages of excellent PC combustion behavior and longer electrode life-span.The scientific principle of how to generate the AC plasma arc was elaborated in detail.First,the experiments on life-span of electrodes inside AC plasma generator had been conducted,finding a workable way to extend its life-span beyond 530 hours.Second,a new AC plasma burner specifically designed for lean coal according to the principle of PC staged combustion had been illustrated with diagrams and then used to ignite the PC-air stream under four kinds of conditions with a varying AC plasma power from 150 kW to 300 kW,focusing on analyses of the influence of AC plasma power on combustion behaver,such as combustion temperature,carbon burnout rate as well as PC combustion regime.The following results showed that in the case of the power of the AC plasma was P=300 kW,a satisfied PC combustion process could achieved,with the average PC combustion temperature of about 940°C,combustion flame length of 6.3 m,and the total carbon burnout rate of up to 52.2%.In addition,about 80%of the nozzle outlet section was filled with bright flame,while 81%of the PC was in zone of the cylindrical flame regime.The PC combustion modes were changed repeatedly during the process of combustion,which went from homogeneous combustion mode at initial ignition stage to combined combustion mode and heterogeneous combustion mode at middle stage,finally to combined combustion mode at later stage.The research conclusion in this paper has proved that the AC plasma ignition approach is feasible and effective to ignite low-rank coal without the present of fuel oil.展开更多
文摘In addition to the matured ＂Laser Inertial Fusion Energy （LIFE）＂ with spherical compression of deuterium-tritium （DI） for a pure fusion engine or for fusion-fission-hybrid operation, a very new scheme may have now been opened by igniting the neutron-free reaction of proton-boron-11 （p-^11B） using side-on block ignition. Laser pulses of several petawatt power and ps duration led to thc discovery of an anomaly of interaction, if the prepulses are cut off by a factor 108 （contrast ratio） to avoid relativistic self focusing. In this case the Bobin-Chu conditions of side-on ignition of solid fusion fuel can be applied after several improvements leading to energy gains of 10,000 similar to the Nuckolls-Wood ignition with extremely intense 5 MeV electron beams. In contrast to the impossible laser-ignition of p-^11B by the usual spherical compression, the side-on ignition is less than ten times only more difficult of DT ignition. This p-^11B fusion produces less radioactivity per gained energy than burning coal. After encouraging success with computations based on the different nuclear cross sections, next steps are focusing on stability and transport problems.
基金supported by the national natural science foundation of china(Contract No.51806132)doctor start-up capital of Shanxi University(No.20174462)。
文摘In order to achieve the target of reducing oil consumption to zero for pulverized coal(PC)boiler in power plant,the paper developed a novel coal pulverized ignition approach,called as Alternating-Current plasma(AC plasma)ignition,with the advantages of excellent PC combustion behavior and longer electrode life-span.The scientific principle of how to generate the AC plasma arc was elaborated in detail.First,the experiments on life-span of electrodes inside AC plasma generator had been conducted,finding a workable way to extend its life-span beyond 530 hours.Second,a new AC plasma burner specifically designed for lean coal according to the principle of PC staged combustion had been illustrated with diagrams and then used to ignite the PC-air stream under four kinds of conditions with a varying AC plasma power from 150 kW to 300 kW,focusing on analyses of the influence of AC plasma power on combustion behaver,such as combustion temperature,carbon burnout rate as well as PC combustion regime.The following results showed that in the case of the power of the AC plasma was P=300 kW,a satisfied PC combustion process could achieved,with the average PC combustion temperature of about 940°C,combustion flame length of 6.3 m,and the total carbon burnout rate of up to 52.2%.In addition,about 80%of the nozzle outlet section was filled with bright flame,while 81%of the PC was in zone of the cylindrical flame regime.The PC combustion modes were changed repeatedly during the process of combustion,which went from homogeneous combustion mode at initial ignition stage to combined combustion mode and heterogeneous combustion mode at middle stage,finally to combined combustion mode at later stage.The research conclusion in this paper has proved that the AC plasma ignition approach is feasible and effective to ignite low-rank coal without the present of fuel oil.
文摘通过试验研究的方法得到了2种低挥发份煤种等离子点火时的喷枪功率、煤粉浓度和一次风速等运行参数。航天大功率可调节等离子点火试验台以660 MW四角切圆煤粉锅炉单只燃烧器为原型,按照1∶1比例搭建。试验结果表明,为实现成功点火,对于Vdaf（干燥无灰基挥发份含量）为22.14%的贫瘦煤,等离子点火喷枪输出功率不低于386 k W,点火煤粉浓度不低于0.24 kg/kg,点火初期一次风速控制在18.2-19.2 m/s为宜;对于Vdaf为16.4%的贫煤,等离子喷枪输出功率不低于435 k W,点火煤粉浓度不低于0.27 kg/kg,一次风速应控制在18.2-19.2 m/s范围之内。
