Effects of Heat Transfer Characteristics of R32 and R1234yf with Al₂O₃ Nanoparticle through U-Bend Tube Evaporator

Table 4

Properties of R32, R134a, and R1234yf [44–46] at and , 0.2928, and 0.3158 MPa, respectively.

Properties	R134a		R32		R1234yf
	Liquid	Vapor	Liquid	Vapor	Liquid	Vapor
Density (kg/m^3)	1294.8	14.428	1055	21.98	1176.3	17.64
Specific heat, Cp (J/kg·K)	1341	897.23	1745	1251	1289.3	926.18
Thermal conductivity (W/m·K)	0.0920	0.0115	0.1248	0.01284	0.0714	0.0116
Viscosity (kg/m·s)	0.000266	0.0000107	0.000124	0.00001228	0.000204	0.0000103
Molecular weight (kg/kmol)	102.03	102.03	52	52	114.04	114
Surface tension (N/m)	0.0114	0.0114	0.007	0.007	0.0094	0.0094