solar vacuum tube

Our solar vacuum tube: StructureAll-glass double-tube co-axial structureGlass materialHigh borosilicate 3.3 glassExternal pipe diameter and thicknessΦ=47±0.7mm &=1.6mm Φ=58±0.7mm &=1.6mmΦ=70±0.7mm &=2.0mmInternal pipe diameter and thicknessΦ=37±0.7mm &=1.6mm Φ=47±0.7mm &=1.6mmΦ=58±0.7mm &=1.6mmPipe length500mm 850mm 1200mm 1500mm 1600mm 1700mm 1800mm 1900mm 2000mm 2100mmAbsorptive coating propertyStructureAL/AL-ALN(H)/AL-ALN(L)/ALNSediment methodSingle target magnetron sputtering platingSpecific absorption0.90 0.93(AM1.5)Emission ratio0.05 0.075(80°C±5°C)Vacuum tightness5.0×10-3 PaIdle sunning property parameters220 260 m².°C /KWSolar irradiation for obtaining a preset water temperatureH≤4.7MJ m²(Φ58)H=4.1 4.4 MJ/ m²H≤3.7MJ/ m²(Φ47)H=3.1 3.4 MJ/ m²Average heat loss coefficient0.6 0.7W/(m².°C)Resistant Hail25mmLife aged15 years