China best quality Three-target solar vacuum tube for solar water heater

Structure

Entire glass double barrel coaxial structures

Material          

Glass tube material: borosilicate glass 3.3

Outside diameter    

Φ47±0.7mm  &=1.6mm Φ58±0.7mm  &=1.6mm

Internal diameter    

Φ37±0.7mm  &=1.6mm Φ47±0.7mm  &=1.6mm

Specification length     

47-1500mm/1600mm/1800mm

58-1500mm/1600mm/1800mm/2000mm/2100mm

Selective absorber coating material   

Cu SS-ALN(H)/SS-ALN(L)/ALN

Solar absorption efficiency     0.90~0.95(AM1.5)

Launch ratio     0..04~0.06(80^oC±5^oC)

vacuum degree      

  P≤3.0×10¯³(Pa)

Maximum stagnation temperature   

260~300^oC

Average heat loss coefficient       

U_LT =0.4~0.6w/(m².^oC)

Resistance performance        

Φ≤ 25mm