内燃机余热二甲醚水蒸气耦合制氢输运机理及反应器优化研究

Hydrogen is regarded as an ideal clear power source for the future. The steam reforming of dimethyl ether (DME) has attracted much attention as a hydrogen carrier because it reforms at low temperatures and high hydrogen selectivity. The high efficiency consumer, response delay, and control difficulties of heat and mass transfer in the reforming process are the main obstacles in the process of reforming technology. In this project, the theories of heat transfer, thermodynamics, fluid mechanics, Multidisciplinary design optimization, and are conducted to the numerical simulations of heat and mass transfer with kinetics of DME reforming using exhaust gas as the heat sources. The reaction system will be thermodynamically analyzed on the basis of energy and chemical equilibrium. The best operation zones will be confirmed on the analysis of thermodynamically analysis. A two-dimensional mathematical model will be presented for describing the complex physical and chemical processes in the reformer in the best operation zones. A system for experiment and measurement will be designed to verify and modify the model. Multidisciplinary and multi-objective optimization design methods will be applied in the design of steam reforming reactor based on the heat transfer model, thermo dynamical model, and heat and mass transfer model. The results of the study can optimize the performance of the hydrogen production system of vehicles and environmental pollution problems.

氢气作为一种理想的车用可替代能源一直备受关注。二甲醚水蒸气重整制氢具有反应条件温和，氢选择性高等优势成为近期研究的热点，但存在系统能耗大，动态响应滞后和热质传输控制难等问题。本项目以内燃机排气作为二甲醚水蒸气重整反应热源，将传热学、热力学、流体力学、化学反应动力学和多学科优化设计等相关理论引入到二甲醚水蒸气重整制氢系统的研究中。建立内燃机排气与二甲醚水蒸气耦合重整过程的传热学、热力学模型，理论上确定系统低能耗，高产氢热效率下的优化操作参数区间；基于能量守恒与质量守恒基本原理，在理论优化参数区间内，建立非稳定条件下气固之间热质传输与反应动力学耦合模型，并搭建实验系统对模型进行验证与修正。基于所建立的传热学模型、热力学模型和热质传输模型，采用多目标多学科协同优化的研究方法对重整制氢微反应器进行优化设计研究，从而优化车载重整制氢系统性能，对解决能源危机与环境污染具有重要的意义。

氢气作为一种车用可替代能源成为近期研究的热点，车载重整制氢技术是解决汽车氢源问题的重要技术之一。二甲醚水蒸气重整制氢具有反应条件温和，氢选择性高等优势但存在系统能耗大，动态响应滞后和热质传输控制难等问题。本项目以内燃机排气作为二甲醚水蒸气重整反应热源，将传热学、热力学、流体力学、化学反应动力学和优化设计等相关理论引入到二甲醚水蒸气重整制氢系统的研究中。建立了内燃机排气与二甲醚水蒸气耦合重整过程的传热学、热力学模型，获得了温度、水醚比等参数对产氢效率的影响规律。理论上确定了系统低能耗，高产氢热效率下的优化操作参数区间；基于能量守恒与质量守恒基本原理，在理论优化参数区间内，获得了二甲醚重整制氢宏观动力学方程式并建立了气固之间热质传输与反应动力学耦合模型，搭建了实验系统对模型进行验证与修正。基于所建立的传热学模型、热力学模型和热质传输模型，采用多目标的研究方法对重整制氢微反应器进行了优化设计研究，基于拓扑优化理论优化了车载重整制氢系统性能。本项目的研究结果可为混合动力汽车与燃料电池汽车重整制氢系统的研究提供理论与数值基础，对解决能源危机与环境污染具有重要的意义。