质量和能量严格守恒的蒸发器动态仿真模型

An Intrinsically Mass and Energy Conservative Model for Transient Simulation of Evaporator

现有用于蒸发器动态仿真的移动边界模型都是基于质量和能量守恒方程展开获得,而展开过程中存在误差,从而导致了现有模型质量和能量不严格守恒,进而影响仿真精度。为了保证求解过程质量和能量的严格守恒,本文选取蒸发器内制冷剂总质量和总能量作为控制方程的状态参数,直接将质量和能量守恒方程作为控制方程求解,从而避免了方程展开的误差。为了在已知制冷剂总质量和总能量的情况下求解蒸发器内制冷剂分布情况和制冷剂状态,本文开发了制冷剂不同分布情况的计算公式和计算方法。仿真案例表明,新方法在仿真48 h蒸发器性能中,质量和能量严格守恒,计算稳定,仿真结果和实验结果吻合。

The existing moving-boundary models for evaporators are obtained by expanding the continuity and internal energy equations,and the error caused by the expansion results that the models are not intrinsically conservative on both mass and energy,resulting accuracy deterioration. To guarantee intrinsically conservative on both mass and energy in calculation,the mass and internal energy are selected as the state variables,and the continuity and internal energy equations are directly solved to avoid the expansion error. The equations and algorithms for refrigerant state and phase distribution in evaporator are developed when the mass and internal energy are given. The case study shows the new model is steady and intrinsically conservative on both mass and energy in the performance simulation of 48 hours,and the simulation results agree well with the experimental data.