Rick Smith

Development of Vipertex EHT Solar Surfaces for Enhanced Energy Transfer Applications

Solar energy production is an important source of green energy that utilizes various thermal designs. Development and modeling of enhanced photovoltaic–thermal solar surfaces is the subject of this study. Design criteria include maximization of the overall energy transfer; minimization of material; and a minimization of any friction increases that might occur in the flowing fluid; and all of these are required while at the same time a structurally superior surface is necessary. Most current designs involve the transfer of energy across a flat and unenhanced solar surface. Current surfaces utilize old technology, making them prime candidates for redesign and improved process performance. Previously developed Vipertex EHT series solar surfaces were tested and found to provide an enhanced energy exchange surface, increased heat exchange surface area, lighter structure, and structural rigidity that exceeds current surfaces using the same amount of material. Vipertex solar surfaces that meet those requirements are produced through material surface modifications and result in additional heat transfer surface area, increased energy absorption, increased fluid turbulence, generation of secondary fluid flow patterns, and produces a disruption of the thermal boundary layer. These enhanced surfaces provide important changes to solar surface design that allow the advancement of thermal solar devices.

Modeling Fluid Flow of Vipertex Enhanced Heat Transfer Tubes

Abstract Conservation of energy plays an important role in the design of today’s process systems. A wide variety of industrial processes involve the transfer of heat energy and many of those processes employ old technology. These processes would be candidates for a redesign that would achieve improved process performance. Utilization of an enhanced heat transfer surface is an effective method to be utilized in order to develop high performance thermal systems. Enhanced heat transfer surfaces can be produced through material surface modifications that result in: an increase in fluid turbulence, generation of secondary fluid flow patterns, disruption of the thermal boundary layer and additional heat transfer surface area. Modeling single phase fluid flow near an enhanced heat transfer surface is the subject of this study. Criteria include the maximization of the overall heat transfer coefficient; minimization of pumping power; and minimization of the rate of surface fouling. Through the use of computational fluid dynamic (CFD) methods, Vipertex™ was able to develop an optimized, three dimensional, enhanced heat transfer surface. This study details the development of an enhanced surface and its effects on the overall heat transfer, fouling and pumping requirements. The Vipertex 2EHT enhanced heat transfer surface was optimized, then manufactured into tubes and evaluated experimentally to validate its design. Original designs of Vipertex enhanced heat transfer surfaces showed average heat transfer performance gains of approximately 30 percent. Optimized Vipertex EHT enhanced surfaces, are able to increase heat transfer for some flow conditions by more than 200%. Designs that incorporate the Vipertex EHT enhanced surfaces are able to increase heat transfer, minimize total costs and conserve energy. These enhanced surfaces provide an important method to advance the design of heat exchange devices.