Experimental Study On The Heat Transfer Performance Of An Annular Heat Pipe

There are still some main problems in energy utilization in China,such as low utilization efficiency,poor economic benefit and great pressure on ecological environme nt.For special industries such as pharmaceuticals and foodstuffs,high temperature sterilizat io n will waste a lot of heat and cooling water,and some products require sterile heat exchanger,must strictly avoid the products before sterilization contact with sterilized products and achieve no hygienic dead angle,in order to prevent cross-contamination,but it is diffic ult to find energy recovery devices that can meet these requirements.In order to meet the above requirements,a new type of heat pipe system(annular flow heat pipe)is designed based on the principle of gravity heat pipe.In this paper,an experimental device of annular flow heat pipe is developed,and a cold and hot water circulation system is established.The heat transfer performance of annular flow heat pipe at different filling and inclination angles is studied experimenta ll y when water and R134 a are used as two environmentally friendly refrigerants.The results show that: 1.When distilled water is used as working fluid of heat pipe,the heat transfer performance of annular flow heat pipe increases first and then decreases with the increase of fil ing quantity,and the optimal fil ing quantity of annular flow heat pipe is 30%.With the decrease of inclination angle,the heat transfer performance of annular flow heat pipe rises first and then decreases,and the optimal inclination angle of annular flow heat pipe is 5°~15°;2.R134 a is used as working fluid of heat pipe.With the increase of filli ng quantity,the heat transfer performance of annular flow heat pipe rises first and then decreases,and the optimum fil ing range of annular flow heat pipe is 55%~60%.With the decrease of inclination angle,the heat transfer performance of annular flow heat pipe rises first and then decreases,and the optimum inclination angle of annular flow heat pipe is 5° ~15°;3.The comparative experimental study of two different environmenta ll y friendly working substances shows that when distilled water is used as working fluid of annular heat pipe,its heat transfer performance is better.In this paper,an experimental study on heat transfer performance of annular flow heat pipe is carried out,which provides an effective way of energy recovery for food or medicine industries and data support for practical engineering applications...