Formation of internal temperature pinches in condensers and evaporations for hydrocarbon refrigerant mixtures

摘要

Zeotropic mixtures are increasingly used as substitutes for CFCs and HCFCs in heat pump systems. THere is also a world wide interest in the use of hydrocarbon fluids as working fluids in refrigeration and heat pump systems. WHile zetropic mixtures can be used effectively to reduce the entropy generation in the condenser and evaporator, pinching of temperature profiles can occur due to the non linear variation of the phase enthalpy of the working fluids during phase change. In this paper we discuss the method for the design of condensers and evaporators for zeotropic mixtures.