纳米TiO_(2)对NH_(3)-H_(2)O-LiBr工质降膜吸收性能的影响

Influence of Nano TiO_(2) on Falling Film Absorption of Ternary NH3-H2O-LiBr Working Fluid

为了探讨纳米TiO_(2)对三元NH_(3)-H_(2)O-LiBr工质降膜吸收的影响,本文利用数值分析建立了三元工作流体薄膜吸收的连续方程、能量方程和组分质量平衡方程,采用Matlab软件进行编程和计算纳米流体的降膜吸收性能,将其与实验数据进行对比验证,并进一步分析了纳米TiO_(2)质量分数、初始氨浓度、初始温度、冷却水进口温度、吸收压力和下降薄膜管长度对薄膜吸收性能的影响。研究表明:添加纳米TiO_(2)可以增强降膜吸收的传质速率,主要原因为液膜中氨的扩散系数增加。当纳米TiO_(2)质量分数从0%增加到0.1%、0.3%和0.5%时,扩散系数分别增加了3.44倍、6.42倍和11.76倍。此外,增加初始氨浓度、降低初始温度、提高冷却水进口温度或降低吸收压力都可以提高最终溶液的饱和度。

In order to investigate the impact of nano TiO_(2) on the falling film absorption of the ternary NH3-H_(2)O-LiBr working fluid,the numerical analysis to establish a set of continuous equations governing mass,energy,and component mass balance in the falling film absorption process of the ternary working fluid is employed in this paper.Programming and computational simulations of the absorption performance of the nano fluid are conducted using Matlab software.The results are compared and validated against experimental data.Furthermore,a comprehensive analysis is undertaken to examine the influence of nano TiO_(2) mass fraction,initial ammonia concentration,initial temperature,cooling water inlet temperature,absorption pressure,and falling film tube length on the absorption performance.The findings indicate that the addition of nano TiO_(2) enhances the mass transfer rate in falling film absorption,primarily attributed to the increased diffusion coefficient of ammonia within the liquid film.The diffusion coefficient exhibits a significant increase of 3.44 times,6.42 times,and 11.76 times as the nano TiO_(2) mass fraction increases from 0% to 0.1%,0.3%,and 0.5%,respectively.Moreover,elevating the initial ammonia concentration,reducing the initial temperature,increasing the cooling water inlet temperature,or decreasing the absorption pressure positively impacts the saturation level of the final solution.