The thermochemical sulfur-iodine cycle is a potential method for hydrogen production, and the hydrogen iodide (HI) decomposition is the key step to determine the efficiency of hydrogen production in the cycle. To further reduce the irreversibility of various transmission processes in the HI decomposition reaction, a one-dimensional plug flow model of HI decomposition tubular reactor is established, and performance optimization with entropy generate rate minimization (EGRM) in the decomposition reaction system as an optimization goal based on finite-time thermodynamics is carried out. The reference reactor is heated counter-currently by high-temperature helium gas, the optimal reactor and the modified reactor are designed based on the reference reactor design parameters. With the EGRM as the optimization goal, the optimal control method is used to solve the optimal configuration of the reactor under the condition that both the reactant inlet state and hydrogen production rate are fixed, and the optimal value of total EGR in the reactor is reduced by 13.3% compared with the reference value. The reference reactor is improved on the basis of the total EGR in the optimal reactor, two modified reactors with increased length are designed under the condition of changing the helium inlet state. The total EGR of the two modified reactors are the same as that of the optimal reactor, which are realized by decreasing the helium inlet temperature and helium inlet flow rate, respectively. The results show that the EGR of heat transfer accounts for a large proportion, and the decrease of total EGR is mainly caused by reducing heat transfer irreversibility. The local total EGR of the optimal reactor distribution is more uniform, which approximately confirms the principle of equipartition of entropy production. The EGR distributions of the modified reactors are similar to that of the reference reactor, but the reactor length increases significantly, bringing a relatively large pressure drop. The research results have certain guiding significance to the optimum design of HI decomposition reactors.

中文翻译：

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高温氦气加热碘化氢分解反应器熵产生率的最小化

热化学硫碘循环是一种潜在的制氢方法，而碘化氢（HI）的分解是确定循环中制氢效率的关键步骤。为进一步降低HI分解反应中各种传递过程的不可逆性，建立了HI分解管式反应器的一维活塞流模型，以分解反应系统的熵产率最小化（EGRM）为优化目标进行性能优化基于有限时间热力学进行。参考反应器采用高温氦气逆流加热，根据参考反应器设计参数设计优化反应器和改进型反应器。以 EGRM 为优化目标，采用最优控制方法求解反应器入口状态和产氢速率固定条件下反应器的优化配置，反应器总EGR最优值比参考值降低13.3% . 参考反应器在优化反应器总EGR的基础上进行改进，在改变氦气入口状态的条件下设计了两个增加长度的改进型反应器。两个改进后的反应器的总 EGR 与最佳反应器相同，分别是通过降低氦气入口温度和氦气入口流量来实现的。结果表明，传热的EGR占比较大，总EGR的降低主要是由于传热不可逆性降低所致。最优反应器分布的局部总EGR更均匀，大致证实了熵产均分原理。改造后的反应器的 EGR 分布与参考反应器相似，但反应器长度显着增加，带来了较大的压降。研究结果对HI分解反应器的优化设计具有一定的指导意义。