What are the performance standards for solar water heater engineering collectors?

May 20,2019
The solar water heater engineering collector shall have a factory inspection certificate and a performance test report issued by the national quality supervision and inspection agency. The performance indicators shall comply with the requirements of relevant national standards.
1, thermal performance

Steady-state, quasi-steady-state transient efficiency without reflectors of the all-glass vacuum tube solar water heater engineering collector's instantaneous efficiency intercept 7 . , "It should be no less than 0.6, the instantaneous efficiency intercept of the collector of the all-glass vacuum tube solar water heater with reflector 7 (), a should be no less than 0.50 •

The FR (TO) of the flat solar water heater engineering collector is not less than 0.68, wherein FR is a heat transfer factor, less than 1; r is the solar transmittance of the transparent cover; a is the solar absorption ratio of the heat absorber. The average heat loss coefficient of the all-glass vacuum tube solar water heater project collector should be no more than 2.5WAm2•K). The FR of the flat solar water heater engineering collector [nine is not more than 6.0WAm2^K).

2, optical performance

The solar transmittance of the cover layer of the cover solar radiation flat panel solar water heater project collector should be no less than 0.78. The glass tube material of the all-glass vacuum solar collector tube should be borosilicate glass 3.3, and the glass tube solar transmittance r > 0.89 (atmospheric quality 1.5, ie AM1.5).

The solar absorption ratio of the coating solar absorption is not lower than 0.92 than that of the flat solar water heater engineering collector coating. The all-glass vacuum solar collector selectively absorbing coating has a solar absorption ratio of 86 (AM 1.5). The hemispherical emission ratio of the coated hemisphere emission to the all-glass vacuum solar collector selective absorbing coating is eh < 90.09 (80 ° C ± 5 ° C).
3, mechanical properties

The pressure collector of the pressure-resistant solar water heater should have sufficient pressure bearing capacity, and its pressure resistance should meet the requirements of the system's most suitable working pressure; under normal circumstances, the working pressure range of the pressure-bearing system should be 0.3~l.OMPa. The solar water heater engineering collector shall pass the pressure test stipulated by the national standard, and shall provide the pressure resistance performance test report issued by the State Quality Supervision and Inspection Agency. The designer of the solar water heating engineering system should put forward the working pressure of the solar water heater engineering collector, and should select the solar collector that meets the requirements. The all-glass vacuum solar collector should be able to withstand a pressure of 0.6 MPa.

4, security

Strength and stiffness Solar water heater engineering collectors shall pass the strength and stiffness tests specified by the national standards. After the test, the solar collectors shall be free from damage and obvious deformation. The air-heating solar water heater project collector shall pass the air-drying test stipulated by the national standard. After the test, the solar water heater project collector shall be free from cracking, damage, deformation and other damage. The sun-heating solar water heater project collector should pass the boring test specified by the national standard. After the test, the solar water heater project collector should have no leakage and obvious deformation.

Anti-mechanical impact All-glass vacuum solar collector tube should be able to withstand a steel ball with a diameter of 30mm, free fall at a height of 450mm, and vertically impact the central part of the collector without damage. Flat-panel solar water heater engineering collectors shall be free from scratches, warpage, cracks, cracks, breaks or perforations after passing the tamper-proof (impact resistance) test specified by national standards.

The internal thermal shock solar water heater engineering collector shall pass the internal thermal shock test specified by the national standard. After the test, the solar water heater engineering collector shall be free of leakage, deformation, cracking or other damage.

The external thermal shock solar water heater engineering collector shall pass the external thermal shock test stipulated by the national standard. After the test, the solar water heater engineering collector shall have no obvious deformation and other damage. After the collector enters the water, the thermal performance shall not be generated. Seriously hindered.

Rainwater solar water heater project collectors should pass the rain test specified by national standards. After the test, the solar water heater project collectors should be free of water seepage and damage.
5, durability

The service life of solar water heater engineering collectors should be greater than 15 years. Coating adhesion Flat solar water heater engineering collector heat absorber and shell coating shall be tested without the peeling after testing according to the test method specified in GB/T1720, and reach the level 1 specified in the standard. The salt spray flat solar water heater project collector heat absorber and shell coating shall be tested without the cracks, blistering, peeling and rusting according to the test method specified in GB/T1771. The heat-resistant flat-type solar water heater engineering collector heat absorber coating is tested according to the standard GB/T1735 test method, and the absorption ratio should be more than 95% of the original value.

After the aging flat-panel solar water heater engineering collector heat absorber coating is tested according to the standard GB/T1865 test method, the retention ratio of the absorption ratio a should be above 95% of the original value; the shell coating should be achieved. Level 2 as specified in GB/T17622.