As an important part of the photovoltaic power station, the photovoltaic support carries the main power generation of the photovoltaic power station. The choice of the bracket directly affects the operation safety, breakage rate and construction investment of the photovoltaic module. Choosing the appropriate photovoltaic bracket can not only reduce the project cost, but also reduce the maintenance cost in the later period.
Photovoltaic bracket type
1. According to material classification
According to the different materials used for the main stress-bearing rods of photovoltaic supports, they can be divided into aluminum alloy supports, steel supports and non-metallic supports.
2. Classification according to installation method
Introduction of Fixed Photovoltaic Mounts
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, it can be divided into: the best inclination fixed type, the inclined roof fixed type and the inclination adjustable fixed type.
1. The best inclination fixed type
First calculate the local optimal installation inclination angle, and then all arrays are fixedly installed with this inclination angle. Currently, it is widely used in flat roof power stations and ground power stations.
1) Flat roof - concrete foundation support
The flat roof concrete foundation support is the most commonly used installation form in the current flat roof power station. According to the form of the foundation, it can be divided into strip foundation and independent foundation; the connection between the support column and the foundation can be connected by anchor bolts or directly. The columns are embedded in the concrete foundation.
Advantages: good wind resistance, strong reliability, no damage to the roof waterproof structure.
Disadvantages: The concrete foundation needs to be made first and maintained to a sufficient strength before subsequent bracket installation can be carried out, 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 counterweight is made, saving construction time.
Disadvantages: The wind resistance of the concrete ballast support is relatively poor, and the maximum local wind force needs to be fully considered when designing the weight of the counterweight.
3) Ground power station - concrete foundation support
There are many kinds of concrete foundation supports for ground power stations. According to the different geological conditions of the project, the corresponding installation method can be selected. The following mainly introduces the most common types of cast-in-place reinforced concrete foundations, independent and strip concrete foundations, and precast concrete hollow column foundations. Concrete foundation installation form.
Cast-in-place reinforced concrete foundation
According to different foundation forms, cast-in-place reinforced concrete foundations can be divided into cast-in-place concrete piles and cast-in-place anchor rods.
Advantages: The excavation of the cast-in-place reinforced concrete foundation is small, the amount of concrete reinforcement is small, the cost is low, and the construction speed is fast.
Disadvantages: The construction of cast-in-place reinforced concrete foundation is easily limited by environmental factors such as seasons and weather, and the construction requirements are high. Once it is done, it cannot be adjusted.
Freestanding and strip concrete foundations
Advantages: The independent and strip concrete foundation adopts the reinforced expansion foundation, the construction method is simple, the geological adaptability is strong, and the foundation embedding depth can be relatively shallow.
Disadvantages: Large amount of independent and strip concrete foundation works, more labor required, large amount of earthwork excavation and backfilling, long construction period, and great damage to the environment.
Precast concrete hollow column foundation
Precast concrete hollow column foundations are widely used in power stations with poor geological conditions such as hydro-solar hybrid power stations and tidal flat power stations. At the same time, due to the advantage of the base height, it is also more used in mountain power stations and agricultural light complementary power stations.
4) Ground power station - metal pile support
Metal pile supports are also widely used in ground power stations, and can be mainly divided into screw pile foundation supports and impact pile foundation supports.
Screw pile foundation support
The screw pile bracket can be divided into a flanged spiral pile bracket and a non-Fara disk spiral pile bracket according to whether it has a flange plate; according to the shape of the cotyledons, it can be divided into a narrow-leaf continuous spiral pile bracket and a wide-leaf spaced spiral pile bracket.
Screw piles with flanges can be used for single-column installation or double-column installation, while screw piles without flanges are generally only used for double-column installations.
The pull-out resistance of the wide-leaf spaced screw pile support is better than that of the narrow-leaf continuous screw pile support, and the wide-leaf spaced screw pile support should be given priority in the windy area.
Impact pile foundation support
The impact pile foundation bracket, also known as the metal fiber pole foundation bracket, mainly uses a pile driver to directly drive C-section steel, H-section steel or other structural steel into the ground. This installation method is very simple, but the pull-out resistance is poor.
Advantages: For the metal pile foundation, the steel pile is driven into the soil by a pile driver, without the need to excavate the ground, which is more environmentally friendly; it is not limited by seasonal temperature, etc., and can be implemented in various climatic conditions including northern winter; construction is fast and convenient, The construction period is greatly shortened, and the migration and recovery can be facilitated; the foundation is easy to adjust the height during the piling process.
Disadvantages: It is difficult to drive piling in areas with hard soil; it is easy to damage the galvanized layer when piling in areas with more gravel; poor corrosion resistance in saline-alkali areas.
