Investigation On The Influence Of Operating Parameters And Nano-particle On The Bubble Pump Flow Pattern Of Lithium Bromide Solution

With the rapid development of the domestic economy in recent years,the demand for energy is increasing and the reserve is decreasing.Therefore,how to improve the utilization of energy has been a hot topic.For the bubble pump lithium bromide absorption refrigeration,not only can make full use of low-grade energy as a heat source,but also replace the mechanical pump to reduce high-grade energy consumption.Through reading extensively the paper,it has been found that the solution flow control and related mechanisms of conventional solution pumps replaced by bubble pumps are far from adequate.Therefore the experimental investigation is started form the bubble pump flow type,trying to provide experimental basis for the flow control of the bubble pump solution.In this paper,mainly from the operating parameters,explore the influence of lithium bromide concentration,heating power and anno-additives on the bubble flow pattern and other aspects.A two-stage bubble pump absorption refrigeration experiment bench is set up,and experiments investigated the influence of lithium bromide concentration,heating power and anno-additives on the flow pattern in the lifting pipe.Through the high-speed camera recording and analyzing the change of flow pattern in the lifting pipe under different operating parameters,the characteristics of each flow pattern and the lift of the bubble pump were obtained.Experimental results indicated that:The bubbly flow,slug flow,plug flow,churn flow and annular flow successively occur.The lift amount of solution of slug flow,plug flow and annular flow increases with increasing lithium bromide concentration.The lift amount of solution increases with increasing the amount of nano-CuO in the solution and when the amount of nano-additives is greater than a certain amount,the amount of solution is no longer increased.The collection of temperature and pressure during the experiment were coupled with each flow pattern to get the appearance,duration and conditions for each flow pattern.Experimental results indicated that:The appearance time of each flow pattern increases with increasing concentration of lithium bromide solution and decreases with increasing the amount of nano-Cuo and the heating power.In addition to bubbly flow,the remaining flow duration decreases with increasing concentration of lithium bromide solution,and bubbly flow duration increases with increasing concentration of lithium bromide solution.Flow duration decreases with increasing the heating power and the amount of nano-CuO.