纳米强化氨水发生过程机理分析

Mechanism analysis on performance enhancement of ammonia- water falling film generation by nanofluid

提出一种可以直接测试有、无纳米氨水溶液氨气发生量的氨水纳米降膜发生实验装置,通过有、无纳米的氨水溶液对比实验,发现添加合适纳米颗粒能够增加氨气发生率。结合氨水纳米溶液降膜发生过程试验结果,以及前人关于纳米颗粒强化传热传质方面的研究,分别从纳米粒子的微运动、界面效应、Marangoni效应、纳米流体物性等方面进行强化发生机理分析,证明纳米流体的粒子微运动和纳米流体的物性是纳米流体强化氨水降膜发生的两大主要因素。

This paper presented a falling film generating test bench for testing ammonia vapor generation rate with/without nanoparticles, in which ammonia - water was used as working fluid. The comparative experiments were conducted to study the in- fluence of nanoparticles on generation amount of ammonia vapor. Experimental results show that the test bench can measure the generation amount of ammonia vapor directly, and the generation rate of ammonia vapor can be improved by adding the proper type and mass fraction of nanoparticles in ammonia - water. Considering the experimental results and the previous studies on en- hancement of heat and mass transfer by adding nanoparticles, strengthening mechanism was analyzed from the micro - motion of nanoparticles, interface effect, Marangoni effect and the properties of nanofluids, etc. Analysis results prove that the micro - mo- tion and properties of nanofluids are the two main positive factors when strengthen the process of ammonia falling film.