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基于多孔芯内局部热力学平衡的假设 ,考虑了 Brinkm an和 Forchheim er对 Darcy定律的修正模型 ,针对简化的物理模型中所包含的气液相区域 ,建立了二维分层饱和多孔介质模型 ,以甲醇为工质对 CPL 蒸发器毛细多孔芯内的传热传质过程进行非稳态数值模拟。在不同的热负荷条件下预测气液分层界面的形状和位置、系统由初态达到稳态过程的持续时间 ,讨论压力和温度的分布。由两层饱和模型所得到的计算结果可知 :CPL 系统在启动时 ,为避免高热流时液体脱离多孔区而发生干涸 ,宜采用小负荷启动 ;采用预热器 ,改善蒸气的出口条件 ;增加蒸发器入口处的工质的过冷度 ,有利于增加 CPL 系统启动过程和变工况时的稳定性。文中分析结论为 CPL 系统的优化设计提供参考
Based on the assumptions of the local thermodynamic equilibrium in the porous core, the modified Darcy’s law was considered by Brinkmann and Forchheim er, and a two-dimensional layered saturated porous media model was established for the gas-liquid region contained in the simplified physical model Methanol as working fluid on CPL evaporator capillary porous core heat and mass transfer process unsteady numerical simulation. The shape and position of gas-liquid interface are predicted under different heat load conditions. The duration of the steady state process from initial state to steady state is discussed. The distribution of pressure and temperature is discussed. The results obtained from the two-layer saturated model show that the CPL system should start with a small load in order to prevent the liquid from drying out of the porous zone during high heat flow. The preheater should be used to improve the outlet conditions of the steam. Undercooling of the working fluid at the inlet of the device is beneficial to increase the stability of the CPL system during starting and changing working conditions. The conclusion in this paper provides a reference for the optimal design of CPL system