摘要
在吸收式制冷技术中，通常在溴化锂水溶液中加入表面活性介质以加强水蒸汽的吸收效果。活性介质的强化吸收主要是由吸收中的马拉哥尼效应引起的。通过在溴化锂溶液中添加一种典型的表面活性介质：2-乙基-己醇[CH3(CH2)3CH(C2H5)CH2OH]，并选择两种不同长度的降膜平板(0.3 m和0.6 m)，以实验手段研究在一定工况下，不同活性介质添加浓度、不同降膜流动雷诺数以及两种不同长度垂直降膜平板的传热传质特性。实验结果表明，随着降膜雷诺数Re的增大，降膜吸收的强化效果减弱；当活性介质的添加浓度在5 ppm^300 ppm之间时，吸收强化达到了1.2倍~1.9倍；活性介质对吸收过程的强化效果在较短的降膜长度范围内尤为显著。
In the absorption refrigeration process, surface activating agents are generally added in the aqueous solutions of lithium bromide in order to enhance the absorp tion of water vapor. Such an enhancement by surface activating agents results mainly from the Marangoli effect during absorption. In this paper, experiments on the enhancement of plate falling-film absorption o f aqueous solutions of lithium bromide using the typical surface activating agent, 2-ethyl-1-hexanol [CH3(CH2)3CH(C2H5)CH2OH], were carried out. In particular, the enhanced absorption, heat and mass transfer were investigated through measuremen ts using two falling-film plates of different lengths (0.3 m and 0.6 m) at different volu me fractions of activating agent and falling liquid-film Reynolds numbers. It was concluded from the experiments that the enhancement of falling-film absorption decreases with the i ncrease of falling liquid-film Reynolds number. The enhancement of absorption increases by a factor of 1.2~1.9 with a volume fraction of activating agent between 5 ppm^300 ppm. The enhancement of absorption using the activating agent is particularly notable in the range of relatively short falling-film.
出处
《能源研究与信息》
2001年第2期74-83,共10页
Energy Research and Information
基金
上海市重点学科项目
关键词
表面活性介质
降膜
吸收强化
溴化锂
水溶液
surface activating agent
falling film
enhancement of absorption
aq ueous solutions of lithium bromide
2-ethyl-1-hexanol
