As an important part of photovoltaic power stations, solar photovoltaic supports carry the main body of photovoltaic power stations. The choice of the support will directly affect the operating safety, damage rate and construction investment of the entire photovoltaic module. Therefore, choosing the appropriate photovoltaic support can not only reduce the project cost but also reduce the subsequent maintenance costs.
Photovoltaic bracket type
1.Classify according to materials
According to the different materials used in photovoltaic brackets, they can be divided into aluminum alloy brackets, steel brackets, and non-metallic brackets. Among them, non-metallic brackets are used less often, while aluminum alloy brackets and steel brackets have their own characteristics.
2.Classify according to the installation method
Second, the introduction of the fixed photovoltaic bracket
The photovoltaic array does not rotate with the change of the incident angle of the sun and receives solar radiation in a fixed manner. According to the setting of the inclination angle, it can be divided into optimal inclination fixed type, inclined roof fixed type and adjustable inclination fixed type.
1.Best inclination fixed type
First, calculate the best local installation inclination angle, and then all arrays are fixedly installed using this inclination angle. It is currently widely used in flat roof power stations and ground power stations.
1) Flat roof-concrete foundation support
Flat roof concrete foundation support is currently the most commonly used installation form in flat roof power stations. According to the form of the foundation, it can be divided into strip foundations and independent foundations. The connection method of the support pillars and foundations can be connected by foundation bolts or directly support the foundation. The columns are embedded in a concrete foundation.
Advantages: good wind resistance, strong reliability, does not damage the roof waterproof structure.
Disadvantages: The concrete foundation needs to be made first and cured to a sufficient strength before subsequent bracket installation can be performed, and the construction period is long.
2) Flat roof-concrete ballast support
Advantages: The construction method of the concrete ballast support is simple, and the support can be installed at the same time when the weight block is produced, saving construction time.
Disadvantages: The wind resistance of the concrete ballast support is relatively poor. When designing the weight of the counterweight, the local maximum wind force needs to be fully considered.
3) Ground power station-concrete foundation support
There are various concrete foundation supports for ground power stations. According to the geological situation of the project, the corresponding installation methods can be selected. The following introduces the most common types of cast-in-situ reinforced concrete foundations, independent and strip concrete foundations, and precast concrete hollow column foundations. Concrete foundation installation form.
Cast-in-situ reinforced concrete foundation
According to different foundation forms, cast-in-situ reinforced concrete foundations can be divided into cast-in-situ concrete piles and pouring anchors.
Advantages: less earthwork excavation for cast-in-place reinforced concrete foundation, less concrete reinforcement, lower cost, and faster construction speed.
Disadvantages: The construction of cast-in-situ reinforced concrete foundations is susceptible to environmental factors such as seasons and weather, and the construction requirements are high. Once completed, it cannot be adjusted.
Freestanding and strip concrete foundation
Advantages: The independent and strip concrete foundation adopts the reinforced extended foundation, the construction method is simple, the geological adaptability is strong, and the foundation embedment depth can be relatively shallow.
Disadvantages: Independent and strip concrete foundations have a large amount of engineering, require more labor, large amounts of earthwork excavation and backfilling, long construction cycles, and great environmental damage.
Precast concrete hollow column foundation
The precast concrete hollow column foundation is widely used in power stations with poor geological conditions, such as water-light complementary power stations and beach-flat power stations. At the same time, due to its high foundation, it is also used in mountain power stations and agricultural-optical hybrid power stations.
4) Ground power station-metal pile support
Metal pile supports are also widely used in ground power stations. They can be divided into spiral pile foundation supports and impact pile foundation supports.
Spiral pile foundation support
Spiral pile brackets can be divided into flanged spiral pile brackets and flangeless spiral pile brackets with or without flanges; according to the shape of the cotyledons, they can be divided into narrow-leaf continuous spiral pile brackets and wide-leaf spaced spiral pile brackets.
Spiral piles with flanges can be used for single-post or double-post installations. Spiral piles without flanges are generally only used for double-post installations.
The wide-leaf spaced spiral pile support has better pull-out resistance than the narrow-leaf continuous spiral pile support. In the area of large wind, the wide-leaf spaced spiral pile support should be given priority.
Impact pile foundation support
Impact pile foundation bracket, also called metal fiber pole foundation bracket, is mainly driven by C pile steel, H beam or other structural steel into the ground with a pile driver. This installation method is very simple, but the resistance to pull is poor.
Advantages: For metal pile foundations, a pile driver is used to drive the steel piles into the soil, which does not require excavation of the ground and is more environmentally friendly. It is not restricted by seasonal temperature and can be implemented in various climate conditions including northern winter; The construction period is greatly shortened, which can facilitate migration and recovery; the foundation is easy to adjust the height during the piling process.
Disadvantages: pile driving is difficult in hard soil areas; pile driving in areas with more gravel is more likely to damage the galvanized layer; poor corrosion resistance in saline-alkali areas.
2, inclined roof fixed
Considering that the load-carrying capacity of inclined roofs is generally poor, most of the components on inclined roofs are installed directly in tiles, and the azimuth and inclination of components are generally the same as the roof. According to the different slope roofs, it can be divided into a tiled roof installation system and a light steel roof installation system.
1) Tile roof installation system
The tile roof installation system is mainly composed of hooks, guide rails, pressure blocks, and bolts.
2) Light steel roof installation system
Light steel roofs, also called color steel tile roofs, are mainly used in industrial plants and warehouses. According to the different types of color steel tiles, they can be divided into angled light steel roofs, upright seam steel roofs and ladder light steel roofs.
Angle-type light steel roofs and upright seam-type light steel roofs mainly use clamps as connectors to fix rails on the roof. Ladder light steel roofs require self-tapping bolts to fix the connectors on the roof.
Regardless of the type of roof, you must measure the "angle relaxation", "upright edge", and "trapezoid" dimensions in the field when selecting the connector to ensure that the connector matches the roof. You must also do this when installing the ladder-type light steel roof bracket. Take good waterproof measures to avoid water leakage at the bolt hole.
3.Adjustable fixed inclination
Adjustable fixed inclination means that at the turning point of the incident angle of the sun, periodically adjust the inclination of the fixed bracket to increase the direct sunlight absorption, and increase the power generation under the slight increase in cost.