Abstract: Since the heat resistance produced by fouling of heat exchangers is great and the energy consumption is high, the fouling of heat exchangers has brought about billions of dollars of economic losses of China industries. In order to realize the foul removing/preventing on line and enhance heat transfer, the miniature hydraulic turbine in the heat exchanger tube is invented. Such hydraulic turbine works of itself while the fluid in the tube flow. As the rotor continuously scrub the heat exchanger tube, it is hard to form the new foul and easy to remove the original foul. Furthermore, the hydraulic turbine enables the sticky boundary layer to be disturbed, and enhance heat transfer. The industrial tests prove that using this miniature hydraulic turbine in the heat exchanger tube has a good effect on foul removing/preventing. Utilizing this technology has great significance in saving energy. The working principles, the rotational speed properties, the flow resistance properties and the industrial tests for foul removing/preventing on line of the miniature hydraulic turbine in the heat exchanger tube are introduced.

Key words: Energy saving, Foul removing/preventing on line, Heat exchanger tube, Heat transfer enhancing, Hydraulic turbine, Coefficients, Estimation, Linear fit, Size effect, Cutting force