Convective Boiling and Condensation Heat Transfer with a Twisted-Tape Insert forR12, R22, R152a, R134a, R290, R32/R134a, R32/R152a, R290/R134a, R134a/R600a

摘要

This paper presents measured local-averaged heat-transfer coefficients for in-tube convective boiling and condensation of several possible alternative refrigerants with a twisted-tape insert. The heat transfer performance of five single component and two azeotropic refrigerants are examined: R12, R22, R152a, R134a, 290, R290/R134a, R134a/R600a. Also, the performance of two zeotropic