直燃机吸收器部件仿真与可视化计算

Component Simulation and Visualization Computing of Absorber in Fire-Directed Absorption Chiller

为研究水平管束式吸收器二元溶液两相流动传热传质规律及部件仿真与可视化方法,将水平管束式吸收器降膜吸收过程分为3个区域,即沿管壁的降膜吸收区、管底部的液滴形成区以及管与管之间的液滴降落区,应用Matlab ODE45求解器仿真求解,并将仿真结果可视化,得到了水平管上溶液温度、浓度、质量流量以及冷却水温度的变化规律,分析了不同溶液质量流量、蒸发温度对吸收器和蒸发器性能的影响.结果表明:每根水平管上的溶液温度都会有一个先降后增的过程,以第1根水平管为例,溶液质量流量为0.024 kg/ms,蒸发温度为12 ℃,润湿率WR=0.8时,经过降膜区后温度从56 ℃下降到47.5 ℃,经过液滴形成区以后,温度又从47.5 ℃升至51.5 ℃.不同蒸发温度工况下的制冷量仿真结果表明,实际运行条件下润湿率维持在WR=0.6～0.8之间.

To study the characteristics of dual-solution two-phase flow heat and mass transfer and methods of component simulation and visualization, the Absorption process of falling film on the horizontal tube bundles were divided into three parts, namely falling film Absorption process along the tube wall, droplet formation process at the bottom of the tube and droplet falling process between the horizontal tubes. Matlab ODE45 solver was applied to solve the simulation model and the simulation results were visualized.The variation trends of solution temperature, concentration, mass flow rate and cooling water temperature on the horizontal tube were (gotten.) The effects of different solution mass flow rate and evaporating temperature on Absorber and evaporator performance were analyzed. Solution temperature goes through a process of rising first and then decreasing on each horizontal tube. The first tube being taken as example, solution temperature decreases from 56 ℃ to (47.5 ℃) after the falling film zone and then rise to (51.5 ℃) after the droplet formation zone when solution mass flow rate is 0.024 kg/ms, evaporating temperature is 12 ℃ and wetting ratio is 0.8. Refrigeration capacity simulation results at different evaporating temperature show the wetting ratio varies between 0.6 and 0.8 on the real running conditions.