Effects of Absorber Emissivity on Thermal Performance of a Solar Cavity Receiver

Table 1

Emissivity and absorptivity of the materials inside the receiver.

Materials	Emissivity	Absorptivity for sunlight	Absorptivity for infrared light
Firebrick; (cavity walls)	0.9	0.9	0.9
Stainless steel tube; (absorber tubes)	0.2,0.4,0.6,0.8	0.8	0.2,0.4,0.6,0.8