Solar water heater Solar vacuum tube

Solar vacuum tubefeatures3- target tubes consist of 3 metals : Aluminum, stainless steel and copper, also AL-SS-CO;it loses heat very little because emissivity of copper ion is lower than aluminum ion by 20%, so the tubes can still work well on -40°C, what’s more, stainless steel ion in the tube can resist high temperature and empty basking, so it also can work well on temperature 400°C. Absorption of 3-target tubes is higher than common tubes by 12%, but it’s emissivity is 30%-40% lower than common one. All glass solar vacuum tubetechnical data StructureAll-glass concentric dual tube geometer Glass materialBorosilicate glass Outer tube diameter and thicknessΦ=47±0.8mm =1500mm±20mm Φ=58±0.8mm =1800mm±20mm Inter tube diameter and thicknessΦ=37±0.8mm =1500mm±20mm Φ=47±0.8mm =1800mm±20mm Absorbing coating propertiesMethod to depositionGraded A1-N/A1 solar selective absorbing coating Absorptance>0.92Emittance<0.08 (80°C)Vacuump ≤ 5 × 10-3paStagnation parameter>230M2.°C/KWSloar rediance exposure for obtaining a preset water temperature <2.8MJ/M2Average heat loss coefficient<0.8W(M2C)Lifetime15 years