one layer solar vacuum tube

Structure

   All glass double tube co-axial structure

 Glass material

   High borosilicate 3.3 glass

 Outer tube diameter and thickness

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

 Inner tube diameter and thickness

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

     Tubes length

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

Absorptive coating property

 Material of coating

  CU/SS-ALN(H)/SS-ALN(L)/ALN

     Sediment methods

  3 target magnetron sputtering plating

 Absorptance

   As=0.92~0.96(AM1.5)

 Emission ratio

   ∑h=0.04~0.06(80°c±5°c)

  Vacuum

   P≤5.0*10-3(Pa)

Idle sunning property parameters

   Y=260~300m2.C/KW

Solar irradiation for obtaining a preset water temperature  

   H≤4.7MJ/m2(Φ58)

   H=3.7~4.2MJ/m2

   H≤3.7MJ/m2(Φ47)

   H=2.9~3.2MJ/m2

Average heat loss coefficient

    -U(LT)=0.4~0.6W/(m2.°c)