Group C particles are often regarded as non-fluidizable but have proven to effectively fluidize with nanoparticle addition,which results in small bubbles and a high gas holdup in the dense phase during the experiments...Group C particles are often regarded as non-fluidizable but have proven to effectively fluidize with nanoparticle addition,which results in small bubbles and a high gas holdup in the dense phase during the experiments.Group C^(+)particles provide an increased surface area for gas-solid contact and improve the reaction performance,especially for gas-phase catalytic reactions.On the basis of a previous study of the ozone decomposition reaction using Group C^(+)particles,a two-phase model was used to evaluate the reactor contact efficiency,and was used to compare the partial oxidation performance of the n-butane to maleic anhydride reaction in fluidized-bed catalytic reactors of Group C^(+)and Group A particles.The reactor with Group C^(+)particles achieved a higher n-butane conversion and MAN yield compared with that using Group A particles,based on the identical catalyst quantity or on the same gas residence time.Therefore,the reactor with Group C^(+)particles can achieve the same reaction conversion and yield with fewer catalysts or a smaller reactor size,or both.Therefore,the fluidized bed catalytic reactor of Group C^(+)particles is expected to be of major significance in industrial processes,especially for gas-phase catalytic reactions.展开更多
The three-dimensional numerical simulation of two-phase plume flow of solid propellant micro-thrusters was developed.Then it was used to investigate the plume interference effect by combining the direct simulation Mon...The three-dimensional numerical simulation of two-phase plume flow of solid propellant micro-thrusters was developed.Then it was used to investigate the plume interference effect by combining the direct simulation Monte Carlo(DSMC) method for multi-component gas flow with the two-way coupling model for two-phase rarefied flow.At different space between the two micro-thrusters and different wall temperature,the plume interference effect was analyzed specifically.The results show that under the plume interference effect the gas is compressed and the flow direction is changed,which resulted in the increasing of gas pressure and temperature;solid phase made no significant effect on the flow parameters of gas phase;with the rising of the space between the two micro-thrusters,the maximum pressure decreased and the maximum temperature increased in the domain under the plume interference effect;the wall temperature could influence the temperature of the gas which is extremely close to the wall,but not the gas pressure.展开更多
文摘Group C particles are often regarded as non-fluidizable but have proven to effectively fluidize with nanoparticle addition,which results in small bubbles and a high gas holdup in the dense phase during the experiments.Group C^(+)particles provide an increased surface area for gas-solid contact and improve the reaction performance,especially for gas-phase catalytic reactions.On the basis of a previous study of the ozone decomposition reaction using Group C^(+)particles,a two-phase model was used to evaluate the reactor contact efficiency,and was used to compare the partial oxidation performance of the n-butane to maleic anhydride reaction in fluidized-bed catalytic reactors of Group C^(+)and Group A particles.The reactor with Group C^(+)particles achieved a higher n-butane conversion and MAN yield compared with that using Group A particles,based on the identical catalyst quantity or on the same gas residence time.Therefore,the reactor with Group C^(+)particles can achieve the same reaction conversion and yield with fewer catalysts or a smaller reactor size,or both.Therefore,the fluidized bed catalytic reactor of Group C^(+)particles is expected to be of major significance in industrial processes,especially for gas-phase catalytic reactions.
文摘The three-dimensional numerical simulation of two-phase plume flow of solid propellant micro-thrusters was developed.Then it was used to investigate the plume interference effect by combining the direct simulation Monte Carlo(DSMC) method for multi-component gas flow with the two-way coupling model for two-phase rarefied flow.At different space between the two micro-thrusters and different wall temperature,the plume interference effect was analyzed specifically.The results show that under the plume interference effect the gas is compressed and the flow direction is changed,which resulted in the increasing of gas pressure and temperature;solid phase made no significant effect on the flow parameters of gas phase;with the rising of the space between the two micro-thrusters,the maximum pressure decreased and the maximum temperature increased in the domain under the plume interference effect;the wall temperature could influence the temperature of the gas which is extremely close to the wall,but not the gas pressure.
