【作者】 武斌；

【导师】 王天宇；

【作者基本信息】 哈尔滨工业大学 ， 动力工程及工程热物理， 2023， 硕士

【摘要】 光催化分解水制氢技术具有原料丰富、产物清洁、过程可持续等诸多优点,有望为人类解决能源与环境危机做出重要贡献。悬浮型光催化分解水制氢反应器结构简便、产氢效果好,被广泛应用于光解水制氢过程。目前光解水制氢领域的研究成果多集中在改进合成光催化剂方面,对悬浮型光解水制氢反应器内流动、辐射和反应细节的分析研究相对不足。因此,本课题拟针对悬浮型光解水制氢反应器开展数值模拟和实验研究,重点分析光解水制氢过程中的多相反应流动细节,并考察光强、温度、流速等因素对反应器产氢效果的影响。采用欧拉-欧拉模型求解悬浮型光解水制氢反应器内的多相流,通过耦合组分输运模型、辐射模型以及化学反应模型实现对光解水制氢过程的模拟。开展了铂负载二氧化钛光催化分解水产氢实验,结果表明,铂负载量为1wt%时产氢效果最好,牺牲剂为乙醇时反应器平均产氢速率最大,反应2h后乙醇的消耗率小于1.2%。参考文献对一个悬浮型光解水制氢反应器开展了多工况模拟研究,模拟结果与文献中的实验数据吻合良好。对悬浮型顶照密闭式光解水制氢反应器开展了模拟研究,分析了颗粒流动特性、辐射强度和反应速率分布特性以及不同操作条件下的反应器产氢速率。结果表明,催化剂颗粒在反应器内表现出非均匀分布特征,化学反应在颗粒稀疏区和高颗粒浓度梯度区对颗粒流动特性存在较大影响。当温度为293K、入射辐射强度小于1000W·m^-2时,该反应器的产氢速率低于1μmol·s^-1。入射辐射强度和温度越高,反应器产氢速率越大,增大搅拌子转速会略微降低反应器产氢速率。对悬浮型侧照开放式光解水制氢反应器开展了模拟研究,分析了固相质量浓度、辐射强度和反应速率分布,考察了反应器产氢速率随操作参数的变化规律,探究了入射辐射对反应器产氢速率的影响。结果表明,反应器产氢速率随着入口质量浓度的增大先上升后下降,随着入口流速和反应器仰角的增大不断上升,反应器仰角对产氢速率的影响最小。入射辐射强度越大,反应器产氢速率越大,反应器产氢速率随操作参数的变化规律与入射方向关系不大。更多还原

【Abstract】 Photocatalytic water splitting for hydrogen production has many advantages,such as abundant raw materials,clean products,and sustainable processes,and is expected to contribute significantly to solving the energy and environmental crisis faced by humanity.The suspended photocatalytic water splitting reactor,which has a simple structure and good hydrogen production efficiency,is widely used in the hydrogen production through water photolysis.Currently,research efforts in the field of hydrogen production through water photolysis are mainly centered on enhancing the performance of photocatalysts,while the analysis on the flow,radiation,and reaction details inside suspended photocatalytic water splitting reactors is relatively insufficient.Therefore,this thesis intends to carry out numerical simulation and experimental research on the suspended photocatalytic water splitting reactors,focusing on analyzing the multiphase reactive flow details in the photolysis of water for hydrogen production,and investigating the influence of factors such as light intensity,temperature,and flow rate on the hydrogen production effect of the reactor.The Euler-Euler model is used to solve the multiphase flow inside the suspended photocatalytic water splitting reactor,and the simulation of the photocatalytic water splitting process for hydrogen production is achieved by coupling the component transport model,radiation model,and chemical reaction model.Experiments on photocatalytic water splitting for hydrogen production using platinum-loaded titanium dioxide are carried out,the results show that the best hydrogen production is obtained when the platinum loading is 1wt%,the maximum average hydrogen production rate is obtained when the sacrificial agent is ethanol,and the ethanol consumption rate is less than 1.2%after 2h reaction.A multi-operating condition simulation study is conducted on a suspended photocatalytic water splitting reactor with reference to a literature,and the results are in good agreement with the experimental data reported in the literature.A suspended top-illuminated closed photocatalytic water splitting reactor is simulated,and the characteristics of particle flow,the distribution of radiation intensity and reaction rate,as well as the hydrogen production rate of the reactor under various operating conditions are analyzed.The results show that the catalyst particles exhibit non-uniform distribution characteristics in the reactor,and the chemical reaction has great influence on the particle flow characteristics in the sparse region and the high concentration gradient region.When the temperature is293K and the radiation intensity is less than 1000W·m^-2,the hydrogen production rate of the reactor is less than 1μmol·s^-1.The higher the incident radiation intensity and temperature,the greater the hydrogen production rate of the reactor,increasing the stirring speed may slightly decrease the hydrogen production rate of the reactor.A suspended side-illuminated open photocatalytic water splitting reactor is simulated,and the distribution of solid-phase mass concentration,radiation intensity,and reaction rate are analyzed,the impact of operating parameters on the hydrogen production rate of the reactor is studied,and the influence of incident radiation on the photocatalytic performance of the reactor for hydrogen production is investigated.The results show that the hydrogen production rate of the reactor first increases and then decreases with the increase of inlet mass concentration,and continuously increases with the increase of inlet flow rate and elevation angle of the reactor,the influence of the elevation angle of the reactor on the hydrogen production rate is the least.The higher the incident radiation intensity,the greater the hydrogen production rate of the reactor,the relationship between the hydrogen production rate of the reactor and the variation of operational parameters is not significantly affected by the incident direction.更多还原