Abstract
Demands to increase performance of modern heat exchange systems are constantly being made; requiring the removal of larger rates of energy, using process units that occupy a smaller unit footprint. Heat transfer enhancement plays an important role in improving energy efficiency and developing high performance thermal systems. Heat transfer processes that involve boiling are typically efficient modes of heat transfer; however the desire to increase efficiencies of those processes have prompted the development of enhanced heat transfer surfaces for boiling processes. A wide variety of industrial processes involve the transfer of heat energy during phase change and many of those processes employ old technology. These processes would be ideal candidates for a redesign that could achieve improved process performance.
Utilization of enhanced heat transfer tubes is an effective method used in the development of high performance thermal systems. Vipertex™ enhanced surfaces, have been designed and produced through material surface modifications, which result in flow optimized heat transfer tubes that increase heat transfer. Considerations in the development of the optimized, three dimensional, enhanced heat transfer Vipertube design include the maximization of heat transfer; minimization of operating costs; and minimization of the rate of surface fouling. This study details the 1EHT bundle boiling results over a wide range of conditions. Results for the 1EHT bundle show combined overall bundle increases of shellside and tubeside heat transfer up to 97 % when compared to the heat transfer enhancement of a smooth tube bundle using typical fluids (n-Pentane, p-Xylene and water); for midpoint shellside Reynolds number values in the range of 2,800 to 20,400; with effective mean temperature difference (EMTD) valuesbetween 15.4 °F (-9.2 °C) and 118.3 °F (47.9°C). Enhanced heat transfer tube bundles that are capableof producing efficiency increases in excess of 90 % are important options to be considered in the design of high efficiency processes. These enhanced tube bundles recover more energy and provide an opportunity to advance the design of many heat transfer products.
