Reinforcement Of External HFO1234ze Condensation And Its Unsteady Characteristic Test

New refrigerant HFO1234ze(E)as a haloalkenes with low flammability,non-toxic,0 ODP and very low global warming potential,it has been widely concerned by scholars at home and abroad.In this experiment,we used HFO1234ze as the working quality,with a smooth tube and three reinforced tubes in the operating temperature of 25℃and 30℃under the experimental study of external condensation,the main conclusions are as follows:(1)In this experiment,Wilson thermal Resistance separation method is mainly used to calculate the enhanced magnification of three reinforced tubes,and the enhanced magnification of C4284-2D with the enhanced magnification of 2.43,C4684-2D to 2.32,C4282-3D is 2.44 by calculation.(2)In the two-dimensional strengthening tube,the relationship between the heat flux density and the external heat transfer coefficient is inversely proportional.The data obtained from the experiment show that when the heat flux density is less than 40kW/m~2,the external heat transfer coefficient of the tube is greatly affected by the condensation temperature.(3)ForHFO1234ze,underthesameworkingcondition,the three-dimensional reinforced pipe is larger than that of the two-dimensional reinforced tube 5-16%.(4)When the condensate temperature is 30℃and the heat flux density is40kW/m~2,the external heat transfer coefficient of the reinforced tube C4284-2D is 15.66kW/m~2,and the external heat transfer coefficient of the reinforced tube C4684-2D is 16.94kW/m2,The external heat transfer coefficient of the reinforced tube C4282-3D is 18.72kW/m~2,and the heat transfer effect of the three-dimensional tube is stronger than that of the two-dimensional reinforced tube.(5)For three reinforced Tubes C4284-2D,C4684-2D,C4282-3D at the same heat flux density,25℃working conditions,the external heat transfer coefficient of the tube is 10.2-14.1 times times that of the smooth tube,30℃The working condition,the external heat transfer coefficient of the tube is 12.3-15.9 times times the smooth tube.The enhanced surface can be seen to achieve a better heat transfer effect.(6)For the working conditions of HFO1234ze,30℃,the heat flux density is77-96kW/m~2,and the total heat transfer coefficient of three-dimensional reinforced tubes is 4.5 times times that of the smooth tube in the same time.The total heat transfer coefficient of two-dimensional reinforced tube is 2.7-4.5 times times that of smooth tube,the change of three-dimensional reinforced tube is larger than that of two-dimensional reinforced tube,the heat change effect is better and the efficiency is higher.