CASCADE REFRIGERATION SYSTEM FOR LOW TEMPERATURES USING NATURAL FLUIDS

Abstract

Cascade refrigeration systems work with two or more serial disposed cycles and can obtain internal temperatures below -60°C, which is necessary for several activities in medicine and scientific research. This paper presents a thermodynamic analysis of cascade system refrigeration using natural refrigerant fluids for ultra low temperatures. These fluids areenvironmentally friendly refrigerant and are an alternative to hydro chlorofluorocarbons (HCFCs) and to hydrofluorocarbons (HFCs). Energy and exergy analyses were performed using a thermodynamic model based on the law of conservation of massand also on the first and second laws of thermodynamics. A simulator was developed to assess the technical practicability of this system, considering it running as a real refrigeration cycle.