脉冲介质阻挡放电臭氧产生的能量转换及温度依赖

发布时间：2018-04-04 05:25

  本文选题：臭氧　切入点：反应动力学　出处：《南昌大学》2017年硕士论文

【摘要】：臭氧是自然界最强的氧化剂之一,其应用领域不断扩展,市场需求也不断扩大。但臭氧产生效率仍然很低,极大的限制了其推广应用。为提高产率降低能耗,本文立足于研究脉冲介质阻挡放电臭氧产生过程的能量转换及温度依赖,通过编译化学反应机理体系,并耦合质量守恒方程、组分守恒方程、电子能量守恒方程以及能量守恒方程,建立合适的反应动力学模型,分别对干空气(N_2-O_2)源和氧气(O_2)源下脉冲放电臭氧发生过程进行分析。具体如下:(1)研究空气源下气体流量、压力以及进口温度对臭氧产生过程的影响,增大气体流量,臭氧质量浓度减小,臭氧产量和产率增大;增大气体压力或进口温度,臭氧的质量浓度、产量和产率都是减小的;随着放电功率的增加,臭氧质量浓度和产量都随之增加并逐渐达到饱和,而臭氧产率先增大后减小。(2)臭氧发生过程中电子能量转换为反应能,气体温度升高消耗的能量以及通过反应器壁传递的热能,探究不同进口温度下三种能量转换率ηreaction,ηgas和ηloss随比能的变化,空气源时,增大比能,ηreaction先增加后减少,ηloss先减少后增加,而ηgas一直是增加趋势。增大气体进口温度,ηreaction随之缓慢减少,而ηloss和ηgas都随之增加。氧气源时,增大比能或气体进口温度,ηloss和ηgas都随之增加,相应的ηreaction随之减少。(3)通过敏感性和生成速率分析获得各粒子反应路径图,并定量分析单个反应对粒子的敏感性系数和生成速率系数随气体平均温度的变化,得到对粒子影响较大的反应途径。干空气源时对臭氧合成影响较大的粒子有O、O_2、O_2(1(35)g)、N_2(A)、NO、NO_2。N_2(A)有助于O原子产生,O_2(1(35)g)、NO、NO_2均会参与分解臭氧,臭氧主要合成反应O+O_2+O_2→O_2+O_3、O+O_2+N_2→N_2+O_3以及主要分解反应O+O_3→2O_2、e+O_3→e+O_2+O的生成速率随着温度的增加都是增加的;氧气源时影响较大的粒子有O、O(1D)和O_2(b1∑)。O(1D)和O_2(b1∑)的存在都会加速臭氧分解。臭氧主要合成反应O+O_2+O_2→O_3+O_2、O+O_2+O_3→O_3+O_3以及主要分解反应O_3+O_3→O_2+O_2+O_2、O_3+O→O_2(b1∑)+O_2的生成速率随着温度的增加都是增加的。
[Abstract]:Ozone is one of the strongest oxidants in nature.However, ozone production efficiency is still very low, which greatly limits its application.In order to improve the yield and reduce energy consumption, the energy conversion and temperature dependence during the generation of pulsed dielectric barrier discharge ozone are studied in this paper. By compiling the chemical reaction mechanism system, the mass conservation equation and the component conservation equation are coupled.The electron energy conservation equation and the energy conservation equation are used to establish a suitable reaction kinetic model to analyze the generation process of the pulse discharge ozone under the dry air NSP _ 2-O _ 2) source and the oxygen O _ 2 / O _ 2 source, respectively.(1) to study the effects of gas flow, pressure and inlet temperature on the ozone production process under an air source, increase the gas flow rate, decrease the ozone mass concentration, increase the ozone production and yield, and increase the gas pressure or inlet temperature,The mass concentration, yield and yield of ozone decrease with the increase of discharge power.However, ozone production increases first and then decreases. 2) during ozone generation, electron energy is converted into reaction energy, energy consumed by gas temperature rising and heat energy transferred through reactor wall.The changes of three energy conversion rates 畏 reaction, 畏 gas and 畏 loss with specific energy at different inlet temperatures are investigated. When air source increases, 畏 reaction increases first and then decreases, 畏 loss decreases first and then increases, and 畏 gas always increases.As the inlet temperature of the gas increases, 畏 reaction decreases slowly, while 畏 loss and 畏 gas increase.When the oxygen source increases the specific energy or the inlet temperature of the gas, 畏 loss and 畏 gas increase, and the corresponding 畏 reaction decreases.The sensitivity coefficient and formation rate coefficient of a single reaction to particles vary with the average gas temperature, and the reaction path which has a great influence on the particle is obtained.The particles that have a greater impact on ozone synthesis in dry air sources are: O / O / S / O / S / O / S / T / T / T / N / O / T / T / O / O / T / O / O / O / T / O / O / O _ 2 / O _ O _ 2 / O _ O _ 2 / O _ 2O _ 2 / O _ O _ 2 / O _ 2O _ 2 / O _ O _ 2 / O _ O _ 2 / O _ O _ 2 / O _ O _ 2O _The main synthesis reaction of ozone, O / O / O / O / O / O / T / O / O / O / T / T / O / O / T / O / O / T / O / O / O / O / O / O / O / O / O / O / O / O / O / O / T / O / O / O / O / O / O / O / O / O / O / O / O / O / O / O / O / O / O / O / OThe existence of the most influential particles in the oxygen source, such as O _ 2O _ 1D) and O_2(b1 鈭，

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