solar vacuum tube(CHCH)

solar vacuum tube: we can supply different size of vacuum tubes.


All glass vacuum tubes are the key component of solar collectors. The evacuated tube is similar to a conventional Dewar flask and consists of two borosilicate glass tubes, a glass with high chemical and thermal shock resistance. The outer side of the inner tube is coated with a sputtered solar selective surface. This coated inner tube is closed at one end and sealed at the other end to the outer tube. The annular space between the outer tube and inner tube is evacuated to virtually eliminate heat loss by conduction and convection.


Sijiwang successfully developed the innovative Advanced Solar Selective Coatings in commercial scale, which achieve the highest thermal efficiency and good thermal stability. Solar selective coatings absorb most solar radiation while simultaneously suppressing the thermal emittance loss from coating surfaces. They vary mainly in their optical property and thermal stability.


Excellent results have been obtained by using DC magnetron sputtering technology. A solar absorptance of 0.94 - 0.96 with an emittance of 0.04 - 0.06 at 100 has been achieved.

Features:
High solar-thermal conversion and low heat loss
Stable advanced coating up to 380
Long time warranty to 15 years
High level vacuum ensure operation under cold weather
Vacuum Tube technology:
Models
47×150
58×180
Weight
1.35±0.12kg
2.29±0.18kg
Structure
All-glass-coaxial double-layer tubes
All-glass-coaxial double-layer tubes
Outer tube diameter
47±0.7mm
58±0.7mm
Inner tube diameter
37±0.7mm
47±0.7mm
Outer Tube thickness
1.6±0.15mm
1.8±0.15mm
Inner tube thickness
1.6±0.15mm
1.8±0.15mm
Tubes length
1542±4mm
1812±4mm
Material of coating
Al N/Al N-SS/Cu
Al N/Al N-SS/Cu
Absorptance
0.94~0.96
0.94~0.96
Emittance
0.04~0.06
0.04~0.06
Vacuum
P≤5×10-3pa
P≤5×10-3pa
Transmittance of Outer Tube
0.91
0.91
Stagnation temperature (height)
270~300
270~300
Heat-loss coefficient
≤0.6w/ m2*)
≤0.6w/ m2*)
Bearing hailstone ability
hailstone diameter25mm
hailstone diameter25mm
Pressure-endure ability
1MPa
1MPa