Evaporation characteristics of multiple droplets of isobutane alkylated effluent during refrigeration
Isobutane alkylation catalyzed by composite ionic liquid is a new technology for the production of high quality and clean gasoline blending components.Maintaining the appropriate temperature during the alkylation reaction is crucial,and effluent cooling emerges as a pivotal measure in this regard.Currently,heat exchangers are used to cool the effluent,but there are shortcomings such as large heat exchange area requirements,high equipment cost and limited cooling effect.The presence of excess isobutane makes it possible to cool the effluent with flash spray.In order to develop a new refrigeration process for alkylated effluents,the evaporation characteristics of isobutane droplets under reduced pressure were studied.Since isobutane is a gas at room temperature and pressure,it is difficult to exist as a liquid.Therefore,a special experimental device was set up to study the evaporation process of isobutane droplets in this work.Single isobutane droplet or multiple droplets were suspended at the top of thermocouples to measure the temperature variation of each droplet,while a high-speed camera recorded the evaporation process.The effects of final pressure,ambient temperature,and droplet spacing on droplet evaporation characteristics were analyzed.The results showed that isobutane droplets underwent intense evaporation and stable evaporation phases,and the evaporation behavior of multi-droplet was similar to that of single droplet.During the stable evaporation phase,all droplets followed the classical d2 law,and the evaporation rate of the edge and center droplets was below the single droplet.With the increase of the final pressure and the decrease of the ambient temperature,the difference between the evaporation rate of the center droplet and the single droplet gradually increased.The temperature field and vapor concentration field during droplet evaporation had a limited range of variation.When the distance between the two droplets increased to 5.48d0,the evaporation rate of the droplet gradually approached that of the single droplet.
NETL
NSTL
万方数据
