Review of Heat Transfer Augmentation within a Plate Heat Exchanger by Different Shapes of Ribs

Heat transfer augmentation techniques (passive, active or a combination of passive and active methods) are commonly used in areas such as process industries, heating and cooling in evaporators, thermal power plants, air-conditioning equipment, refrigerators, radiators for space vehicles, automobiles, etc. Passive techniques, where inserts are used in the flow passage to augment the heat transfer rate, are advantageous compared with active techniques, because the insert manufacturing process is simple and these techniques can be easily employed in an existing heat exchanger. In design of compact heat exchangers, passive techniques of heat transfer augmentation can play an important role if a proper passive insert configuration can be selected according to the heat exchanger working condition (both flow and heat transfer conditions). In the past decade, several studies on the passive techniques of heat transfer augmentation have been reported. Twisted tapes, wire coils, ribs, fins, dimples, etc., are the most commonly used passive heat transfer augmentation tools. In the present paper, emphasis is given to works dealing with different shapes of ribs, and there arrangement because, according to recent studies, these are known to be economic heat transfer augmentation tools. The present review is organized in four different sections: circular ribs with staggered at 90°; circular ribs with staggered at 45°, triangular ribs with staggered at 90° and triangular ribs with staggered at 45°.