Test Background
In recent years, flat-plate solar collectors have experienced rapid recovery growth in China. Selective absorption coatings for flat-plate collectors have received increasing attention, and their optical properties, especially corrosion resistance, have also been highly valued. The salt spray test is used by manufacturers as a means to detect corrosion resistance. The salt spray resistance test of the solar collector absorber can determine the salt spray resistance of the solar collector absorber.
Zhongke Testing Reliability Experiment Center has the reliable performance of various solar collector absorbers and provides professional salt spray resistance test services for solar collector absorbers.
Scope of tests
is divided into: copper, aluminum alloy, copper-aluminum composite, stainless steel, galvanized steel, plastic, rubber, etc. according to material type.
According to the structural form, it is divided into: tube plate type, wing tube type, flat box type, and snake tube type.
According to the type of coating, it is divided into: non-selective absorption coating and selective absorption coating.
Test method
1. Cut three 50 mm × 50 mm samples from the heat absorber, test the solar absorption ratio and normal emission ratio respectively according to the requirements of GB/T 25968 and GB/T 25965, take the average value, and retain 2 decimal places.
2. The sample is subjected to a salt spray resistance test in accordance with the provisions of GB/T1771, and is taken out after 24 hours. The solar absorption ratio and normal emission ratio are tested again in accordance with the requirements of GB/T 25968 and GB/T 25965, and the average value is taken and retained to 2 decimal places.
3. The attenuation of the optical performance of the surface of the heat absorber is based on the coating after the test. The base material should be free of cracks, blisters, peeling and corrosion. There should be no more than 10 pitting corrosion and peelings with a diameter greater than 1 mm in a 50 mm × 50 mm area. The attenuation coefficient of the optical performance of the surface of the heat absorber is ≤0.1, and the adhesion reaches level 1 specified in GB/T 1720.
Test standard:
NB/T 34072-2018 Technical specifications for weather resistance of flat-plate solar collector absorbers
GB/T1720 Paint film adhesion determination method
GB/T1771 Paints and varnishes - Determination of neutral salt spray resistance
GB/T 1865 Paints and varnishes Artificial weathering and artificial radiation exposure Filtered xenon arc radiation
GB/T6682 Analytical laboratory water specifications and test methods
GB/T12936 Solar thermal utilization terminology
GB/T 25965 Test method for normal emission ratio of materials and hemispheric emission ratio of all-glass vacuum solar collector tubes
GB/T 25968 Spectrophotometer test method for measuring solar transmittance and solar absorption of materials
GB/T 26974-2011 Technical requirements for flat plate solar collector absorbers
