EFFECT OF TRIANGULAR RIBS ON THE FLOW AND HEAT TRANSFER CHARACTERISTICS OF HEAT EXCHANGER TUBE

To improve the heat exchange tube's comprehensive performance and achieve enhanced heat transfer with lower flow resistance. The flow and heat transfer characteristics of a newly enhanced tube with triangular ribs were studied by numerical simulation. The results show that the multi -vortex longitudinal swirl developed in the triangular rib enhanced tube can enhance the cold and hot fluid mixing, and make the temperature distribution in the tube more uniform. The field synergy of velocity and temperature gradient was improved and the heat transfer capacity was enhanced. In the triangular rib enhanced tube, reducing the dimensionless pitch ratio of triangular ribs (P * = 0.5, 0.75, 1, and 1.25) and appropriately increasing the area of triangular ribs (A = 8, 12, 16, and 20 mm 2 ) can improve the performance evaluation criteria (PEC). When Re = 8475, P * = 0.5, and A = 20 mm 2 , the maximum PEC = 1.324 is obtained.