Enhanced heat transfer of drag reducing surfactant solutions with fluted tube-in-tube heat exchanger

Solutions containing drag reducing additives also show reduced heat transfe r which limits their use in hydronic cooling and heating systems where heat exchange is critical. For Reynolds numbers 10,000-50,000 and test fluid in let temperatures 50-70 degreesC, a fluted inner tube heat exchanger showed increased heat transfer coefficients for both cationic and zwitterionic/ani onic drag reducing surfactant solutions. The pressure drop penalty for heat transfer enhancement of the cationic surfactant solution flowing through t he fluted tube is high while for the zwitterionic/anionic solution, signifi cant heat transfer improvement was achieved with only a modest pressure dro p penalty. (C) 2001 Elsevier Science Ltd. All rights reserved.