Heat Transfer of Nanofluid in a Double Pipe Heat Exchanger

Table 1

Physical properties of the nanoparticles.

Types of nanoparticles	Nanosized particles	Special surface	Percent purity	Appearance	The apparent density
-Al2O3	20 nm	>160 m^2/g	+99	White powder	0.9 g/m^3
Certificate of analysis (content of elements)
Co	M	N	Cl	V	Ca	Al2O3
≤2 ppm	≤3 ppm	≤70 ppm	≤315 ppm	≤7 ppm	25 ppm	99%