An Experimental Study to Improve Heat Transfer Rate in a Double Pipe Heat Exchanger Using Helical Tape

In this experimental study, a double pipe heat exchanger made of stainless -steel with inner and outer diameters are (11.43 and 16.83 cm) respectively, for two cases plain tube and helical tape with a central rod inserted inside the inner pipe with (1.5 m) length and pitch of (11 cm). the working fluids are air as hot fluid pass through the inner pipe. Heavy fuel oil is a cold fluid flowing through the outer pipe. The results showed that the helical tape inside the inner pipe was better than the smooth tube in the rate of heat transfer as well as the heat transfer coefficient, the overall heat transfer coefficient and effectiveness.