Three target solar vacuum tube for solar water heater

Vauum Tube Structure

All-glass double deck co-axial structure

Glass material

High borosilicate 3.3 glass

Outer tube diameter and glass thickness

Φ=47±0.7mm & =1.6±0.15mm 
Φ=58±0.7mm & =1.6±0.15mm
Φ=70±0.7mm & =2.0±0.15mm

Inner tube diameter and glass thickness

Φ=37±0.7mm & =1.6±0.15mm
Φ=47±0.7mm & =1.6±0.15mm
Φ=58±0.7mm & =1.6±0.15mm

Vacuum Tube Length

800mm,1200mm,1500mm,1600mm,
1800mm,1900mm,2000mm,2100mm,etc

Absorption
coating
property

Coating material

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

Sediment method

Three target magnetron sputtering plation

Absorptivity

=0.92-0.96(AM1.5)

Emission ratio

=0.02-0.05(80°C±5°C)

Vacuum degree

p ≤ 5.0 × 10-3 (PA)

Stagnation temperature(temperature inside of empty evacuated tubes)

260-350°C

Average heat loss

ULT0.4-0.6W/(M2.°C)

Vacuum Tube Lifetime

15years

Hail resistance

30mm

Pressure-endure

1MPa