The experimental apparatus is shown in Fig. 3. In order to
compare the efficiency of nanofluids with water in the same conditions,
two same solar collectors were adopted. As can be seen
from Fig. 3, the title angle of this flat-plate solar collector is 45, and
this experimental investigation was performed at Shunde Polytechnic,
Guangdong, China(latitude is 22400 N and longitude is
11310 E). The area of solar collector is 2 m2 and collector plates
made of 8 parallel strips (copper pipe, inside diameter 8 mm).