氨水吸收式制冷系统性能模拟分析

Simulation Analysis of Performance of Ammonia Absorption Refrigeration System

本文对氨水吸收式制冷系统中主要部件建立稳态集总参数模型进行数值模拟,从定性和定量角度分析氨气浓度对制冷系统性能的影响,并优化影响精馏塔性能的进料状态、发生温度和回流比等参数。研究结果表明,对精馏塔采用塔板效率修正非理想性的平衡级模型,会使设备放大效应明显改善;提馏段对系统性能影响较大,精馏段对精馏效果影响较大;随着发生温度的升高,系统的制冷量先增大,而当发生温度超过最大值时,系统性能下降;并且相似地,存在一个使得系统性能最佳的回流比;不同回流比条件下均有一个最佳发生温度存在,在每个发生温度条件下也能找到最适宜的回流比。

By establishing a steady-state lumped parameter model of the main components in this system, the impact of ammonia concentration to system performance was studied from the qualitative and quantitative terms, and the impact properties such as the material status of distillation column inlet, the generating temperature, reflux ratio and other parameters were optimized. Results show that, using tray efficiency to revise the non-ideal equilibrium stage model makes the device amplification effect obvious. The stripping section has a greater impact on system performance, and the rectifying section has a larger effect on the distillation process. At first, the cooling capacity of the system increases with the occurrence of temperature increases. When the temperature exceeds the maximum value, the system performance declines. Similarly, there is an optimum reflux ratio corresponding to the best performance of the system. Under different reflux ratio condition, there occurres different optimal generating temperature, and the most suitable reflux ratio can also be found in different generating temperature.