Thermal performance of flat plate solar water collector using air bubble injection

The effect of injecting small bubble air into the water stream flowing in two spiral arrangement copper tube 15 m length, 0.012 diameter, and number coils were 11 has been investigated. inner surface solar collector was also painted with a matte black paint mixture nanomaterial (thermal dye 5% TiN). performance examined experimentally Babylon-Iraq, longitude (44.4 E) latitude (32.4 N) under best experimental conditions province during months beginning year. Venturi device used to enter inside tubes mix then flow together collector. experiment included work parts, first part only at four different levels (1,1.5,2,2.5) L/min. second addition injection bubbles, which done levels. Results show that decrease mass rate leads an increase outgoing temperature thus difference inlet outlet cases incoming systems. maximum closed system 36.1 °C for 1 L/min 0.3 L/min., respectively. opened 12.5 L/min, through led difference, while seems have no effect.