Solar Vacuum Tubes

Three-high all-glass vacuum heat collection tube property and specification:
Structure: All-glass double-tube co-axial structure
Glass material: High borosilicate 3.3 glass
External pipe diameter and thickness: Φ =47± 0.7mm &=1.6mm; Φ =58± 0.7mm &=1.6mm; Φ =70± 0.7mm &=2.0mm
Internal pipe diameter and thickness: Φ =37± 0.7mm &=1.6mm; Φ =47± 0.7mm &=1.6mm; Φ =58± 0.7mm &=2.0mm
Pipe length: 800mm; 1200mm; 1500mm; 1600mm; 1800mm; 1900mm; 2000mm; 2100mm
Absorptive coating property: Structure: Cu/SS-ALN(H)/SS-ALN(L)/ALN

Deposition Method: 3 high magnetron sputtering plating
Absorption than: As=0.93~0.96(AM1.5)
Emission ratio: 0.04~0.06(80± 5)
Vacuum tightness: P≤ 50x10-3 (Pa)
Idle sunning property parameters: Y=260~300m2. /KW
Solar irradiation for obtaining a preset water temperature:
H≤ 4.7MJ/m2 (Φ 58) H=3.7~4.2 MJ/m2
H≤ 3.7MJ/m2 (Φ 47) H=2.9~3.2 MJ/m2
Average heat loss coefficient: ULT=0.4~0.6W/(m2. )