58mm solar evacuated tube in solar collector

Three-target  magnetron sputtering

solar vacuum tube

Tube glass

Material

High borosilicate 3.3 glass      &=1.6mm

Thermal expansion coefficient

≤3.3×*0*6K

Transmittance

≥0.*0

Outer tube diameter & thickness

Ø=*7±0.7mm  &=1.6mm

Ø=*8±0.7mm  &=1.6mm

Inner tube diameter & thickness

Ø=*7±0.7mm  &=1.6mm

Ø=*7±0.7mm  &=1.6mm

Tube length

***0/***0/***0mm

***0/***0/***0/***0/***0mm

Vacuum degree

P≤2.0**0*3Pa

Selective absorber 

Material

SS-ALNx/Cu

Absorption ratio

α=0.93~0.*5(AM1.5)

Emission ratio

ε=0.04~0.06 (*0°C±5°C)

Maximum stagnation temperature

Y=**0m2°C/KW

Solar irradiation for stagnation

H=2.9~3.2MJ/m2

H=3.7~4.2MJ/m2

Average heat loss coefficient

ULT=0.4~0.6W/(m2°C)

Mechanical shock resistance

Withstand the  vertical impact of  a steel ball with *0mm  in diameter free falling 

 from the height of **0mm