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Evaluation of heat transfer performance of a laboratory-scale polymer rotary air preheater

Regenerative heat exchangers, which increase the temperature of newly supplied air using the waste heat of exhaust gas, are installed in large thermal systems, such as thermal power plants and industrial boilers, to improve their thermal efficiency. These devices are also known as air preheaters, and the rotary regenerative type has been widely used. The heat transfer performance of a rotary regenerator is enhanced as the heat capacity, which is the product of the density and specific heat, increases rather than the thermal conductivity of heat exchanging plates (HEPs). Studies to replace the existing metal materials with polymers, which are resistant to corrosion and inexpensive, have garnered attention. In this study, the heat transfer performance of HEPs fabricated using polytetrafluoroethylene, Mono Cast nylon, stainless steel, and aluminum is experimentally compared using a laboratory-scale experimental setup. It is confirmed that the polymer materials have similar or larger effectiveness compared to metals within the experimental error.