Tracking photovoltaic bracket
The tracking type photovoltaic bracket moves the photovoltaic array with the change of the incident angle of the sun through the electromechanical or hydraulic device so that the sunlight can be as direct as possible to the panel of the module, and the photovoltaic array's power generation capacity is improved. According to the number of tracking axes, it can be divided into a single-axis tracking system and a dual-axis tracking system.
1.The flat single-axis tracking system
The photovoltaic square array can track the sun along a horizontal axis in the east-west direction to obtain a large amount of power generation, which is widely used in low-latitude areas. According to the presence or absence of an inclination angle in the north-south direction, it can be divided into standard flat uniaxial tracking type and flat uniaxial tracking type with inclination.
2.The oblique single-axis tracking system
The tracking axis is set to a certain tilt angle to the south while rotating in the east-west direction, and the solar azimuth angle is tracked around the tilt axis to obtain greater power generation, which is suitable for applications in higher latitudes.
3.Dual-axis tracking system
Two-axis rotation (vertical axis, horizontal axis) is used to track the solar rays in real-time to ensure that the solar rays are perpendicular to the module board surface at each moment, so as to obtain the maximum power generation, suitable for use in various latitudes.
4. Comparison of several bracket operation modes
Comparison of photovoltaic bracket steel and aluminum and material strength
The bracket is generally made of Q235B steel and aluminum alloy extruded profile 6063 T6. In terms of strength, 6063 T6 aluminum alloy is about 68% -69% of Q235 B steel. Therefore, steel is generally superior to aluminum alloy in strong wind areas and large spans. Profile.
Deflection
The deflection of the structure is related to the shape and size of the profile and the elastic modulus (a parameter inherent to the material) and is not directly related to the strength of the material.
Under the same conditions, the deformation of aluminum alloy profiles is 2.9 times that of steel, and the weight is 35% of steel. In terms of cost, aluminum materials are 3 times that of steel. Therefore, generally in the strong wind area, the span is relatively large, the cost and other conditions of steel are better than aluminum alloy profiles.
Anti-corrosion
At present, the main anti-corrosion methods of the steel are 55-80μm galvanized steel and 5-10μm anodized aluminum alloy.
The aluminum alloy is in the passivation area under the atmospheric environment, and a dense oxide film is formed on the surface, which prevents the surface of the active aluminum substrate from contacting the surrounding atmosphere, so it has very good corrosion resistance, and the corrosion rate increases with time. While decreasing.
Under normal conditions (C1-C4 environment), the thickness of galvanized 80μm can be guaranteed for more than 20 years, but the corrosion rate will be accelerated in high-humidity industrial areas or high-salinity seashores and even temperate seawater. Above and require regular maintenance every year.
Aluminum is far superior to steel in terms of corrosion protection.
Comparison of other aspects
(1) Appearance:
There are many types of surface treatment methods for aluminum alloy profiles, such as anodizing, chemical polishing, fluorocarbon spraying, electrophoretic painting, etc. Beautiful appearance and can adapt to various strong corrosive environments.
Steel is generally hot-dip galvanized, surface sprayed, and painted. The appearance is worse than aluminum alloy profiles. It is also inferior to aluminum profiles in terms of corrosion prevention.
(2) Cross-section diversity
The general processing methods of aluminum alloy profiles include extrusion, casting, bending and stamping. Extrusion production is currently the mainstream production method. By opening the extrusion die, it can achieve the production of any arbitrary cross-section profile, and the production speed is relatively fast.
Steel is generally rolled, cast, bent, stamped, etc. Rolling is currently the mainstream method of producing cold-formed steel. The cross-section needs to be adjusted by the roller wheelset, but after the machine is shaped, it can only produce similar products, and the size can be adjusted, and the cross-sectional shape cannot be changed, such as C-shaped steel, Z-shaped steel, and other sections. The rolling production method is relatively fixed and the production speed is relatively fast.
Recycling of materials
The maintenance cost of steel structures increases by 3% each year, while the aluminum structure supports require almost no maintenance and maintenance, and aluminum materials still have a 65% recovery rate after 30 years. Aluminum prices are expected to increase by 3% each year. After 30 years, it is basically a pile of scrap iron with no recycling value.
Comprehensive performance comparison
(1) Aluminum alloy profiles are light in weight, beautiful in appearance, and excellent in anti-corrosion performance. They are generally used in home roof power stations that require load-bearing and strong corrosive environments.
(2) The steel has high strength and small deflection when subjected to load. It is generally used in ordinary power stations or parts with relatively large forces.
(3) Cost: Generally, the basic wind pressure is 0.6kN / m2 and the span is less than 2m. The cost of aluminum alloy bracket is 1.3-1.5 times that of the steel structure bracket. In the small-span system, (such as the color steel roof), the cost difference between the aluminum alloy bracket and the steel structure bracket is relatively small, and the aluminum alloy is much lighter than the steel bracket in terms of weight, so it is very suitable for home roof power stations.