HEAT TRANSFER CHARACTERISTICS AND EXERGY STUDY OF R744/R1270 IN A SMOOTH HORIZONTAL TUBE

The use of carbon dioxide as alternative refrigerant in refrigeration plants and heat pumps has been focused recently. The experimental investigation of 50/50 blend of R744/R1270 flow in a tube of 1.44m length with an inner diameter of 4 mm is carried out. This paper reports the results of heat transfer coefficient, inner wall temperature, Nusselt number and exergy analysis for inlet temperature between -4 o C and 8 o C.