The flow pattern on the shell side of a helically baffled heat exchanger is near plug flow conditions

which almost eliminates backmixing and dead space on the shell side.The heat transfer coefficient of the helically baffled heat exchanger is much higher than that of conventional segmental baffle heat exchanger at the same pressure drop.In this paper

experiments were conducted for cooling water flowing in the tube side on the helically baffled heat exchanger with lubricating oil as the working medium flowing on the shell side.The tested tubes included one petal-shaped finned tube and one smooth tube selected for performance comparison.The heat transfer coefficients were obtained by using the Wilson plot method and pressure drop on the shell side was directly measured for the two heat exchangers.The relative error of heat transfer coefficient on the shell side was within ±3％.The results showed that the Nusselt numbers and pressure drops on the shell side of the helically baffled heat exchanger with petal-shaped finned tube were 2—2.7 and 1.3—1.4 times larger than those of the helically baffled heat exchanger with smooth tube at constant Reynolds number

respectively.The petal-shaped finned tube could significantly improve the shell side heat transfer performance for the helically baffled heat exchanger.