| Ozone is one of the strongest oxidants in nature,the application field of ozone is expanding and its market demand is increasing.But the ozone generation efficiency is currently rather low,which limits its popularization and application greatly.To achieve high ozone yield and low energy consumption,in this paper,a chemical kinetics model including a detail reaction mechanism system,mass conservation equation,gas-phase species conservation equation,electron energy equation and gas energy equation is developed to investigate the characteristics of energy conversion and temperature dependence in ozone generator using dry-air?N2-O2?and oxygen?O2?pulse dielectric barrier discharge respectively.The main conclusions are as follow:?1?The effects of gas rate,gas pressure and inlet gas temperature on ozone generation have been investigated.While the increase of gas rate leads to a decrease of ozone mass concentration and a higher ozone output and yield;Furthermore,the ozone mass concentration,output and yield both decrease with the increase of gas pressure or inlet gas temperature;Additionally,the ozone mass concentration and output increase as increasing discharge power,and finally saturates,while the ozone yield increases first and then decreases.?2?The energy conversion ratios of total electric energy converted into reaction heat,heat carried by gas and heat loss to ambient,namely ?reaction,?gas and ?loss,are obtained.And then the ratios as a function of the specific energy at different inlet gas temperatures have been studied.In dry-air,as the specific energy increasing,the ratio ?reaction increases first and then decreases,the ratio ?loss decreases first and then increases,while the ratio ?gas increases all through.With the increase of inlet gas temperature,the ratio ?reaction increases slowly,while the ratio ?loss and ?gas both decrease.In oxygen,the ratio of reaction heat ?reaction decreases substantially with increasing specific energy or inlet gas temperatures,correspondingly,?loss and ?gas increase gradually.?3?The detailed reaction pathways including the degree of transformation among species for ozone formation is obtained via sensitivity analysis and rate-of-production analysis,meanwhile,the quantitatively analyzing of sensitivity coefficient and production rate with temperature dependence for each individual reaction is also obtained,then we can acquire the vital reaction pathway on each species.In dry air,O,O2,O2?1?35?g?,N2?A?,NO,NO2 are the most important species for ozone generation.The existence of N2?A?conduce to a higher O concentration,and the existence of O2?1?35?g?,NO,NO2 make against ozone generation.The production rate of ozone via the most important ozone generation reaction O +O2 +O2 ?O2 +O3 and O +O2 +N2 ?N2 +O3 increases linearly with the increase of gas temperature,as well as the destruction rates of ozone via the most important ozone destruction reactions O +O3 ?2O2 and e +O3 ?e+ O2 +O;In oxygen,O,O?1D?and O2?b1??are the most important species for ozone generation,and the existence of O?1D?and O2?b1??make against ozone generation.The production rate of ozone via the most important ozone generation reaction O+O2+O2?O3+O2 and O+O2+O3?O3+O3 increases linearly with the increase of gas temperature,as well as the destruction rates of ozone via the most important ozone destruction reactions O3+O3?O2+O2+O2 and O3+O? O2?b1??+O2. |
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