PV mounting structure installation forms on ground and rooftop
PV mounting structure installation forms on ground and rooftop
With the increasing development of photovoltaics, how to choose suitable photovoltaic brackets according to local conditions is an important link to ensure the safe and efficient operation of the entire photovoltaic system. Starting from the installation form, the existing photovoltaic supports can be roughly divided into two categories: ground photovoltaic supports; roof photovoltaic supports. Next, Starwin Solar will start from different application scenarios and talk about how to choose a photovoltaic support suitable for the project site.
Photovoltaic bracket design and material selection and precautions during construction
1. The installation structure of the photovoltaic array bracket should be simple, strong and durable. The materials used to manufacture and install photovoltaic array brackets must be able to withstand various harsh environments on the project site to ensure 25 years of weathering, corrosion resistance and structural strength. Electroplated aluminum, electroplated steel and stainless steel are all ideal choices. At the same time, the welding production quality requirements of the bracket must meet the requirements of the national standard "Code for Acceptance of Construction Quality of Steel Structure Engineering" (GB50205-2001). The weight of the array bracket should be reduced as much as possible under the design requirements to facilitate transportation and installation.
2. During the construction of the photovoltaic array foundation and support, it is necessary to avoid damage to related buildings and auxiliary facilities as much as possible. If local damage is caused by construction needs, it should be repaired in time after the completion of the construction.
3. When installing photovoltaic arrays on the roof, the embedded parts of the base should be firmly welded or connected to the main structure of the roof. If welding or connection is not possible due to structural restrictions, measures should be taken to increase the attachment between the base and the roof. Focus on it and fix it with wire tensioning method or bracket extension fixing method. After the foundation is completed, the damaged roof or the involved parts should be waterproofed in accordance with the requirements of the national standard "Roofing Engineering Quality Acceptance Specification" (GB50207-2002) to prevent water seepage and rain leakage.
4. The frame and support of the photovoltaic cell module should be reliably connected to the grounding system.
Common ground installation fixed form
Basic form:
1. Hammer into the pile
Measure the distance at the installation site and directly use the pile driver to drive the column into the ground, which is convenient and quick. Before installation, geological and soil testing is required to determine the appropriate penetration depth.
The following types of profiles are suitable for hammer-in-ground piles, which can be selected according to actual conditions:
advantage:
Fast speed and strong adaptability;
High cost performance;
Not subject to seasonal temperature restrictions;
It is convenient to remove the piles and does not affect the reuse of the installation site.
2. Spiral pile
When the installation site is too hard or there are too many gravel, it is inconvenient to hammer the column directly into the ground, spiral piles can be used. Drive the screw-in steel pipe into the ground, and then fix the column on it.
advantage:
Strong adaptability, flexible and diverse combination;
Not subject to seasonal temperature restrictions;
It is convenient to remove the piles and does not affect the reuse of the installation site.
3. Precast cement foundation
If the installation site is not suitable for plug-in piles, you can choose to make a cement foundation. The brackets are placed on the cement foundation and fixed with bolts.
advantage:
Good strength and high precision;
Strong adaptability to the ground.
4. Direct cement pouring
Another form of cement foundation is to directly pour the bracket and cement together. This way. Compared with the above, the time for bolting is saved, but the positioning accuracy of the support column is higher when pouring.
advantage:
Good strength and high precision;
Strong adaptability to the ground.
Common ground support form
1. Plug-in ground fixing form
Plug-in floor fixing bracket
Features:
①The main body of the bracket is made of structural steel, the surface is hot-dip galvanized, and the service life is more than 20 years;
②The parts have good compatibility and easy installation;
③Convenient maintenance;
④ Strong adaptability to the ground.
2. Ground truss fixed form
Ground truss fixed bracket
Features:
①Use screw piles, easy to operate (other ground fixing methods can also be used);
② Adapt to many different types of geology;
③The beam adopts reinforced design aluminum guide rail;
④A slot for installing components is designed on the aluminum guide rail, which is simple and convenient to install and fix.
3. Ground single column fixed form
Ground single column fixed bracket
Features:
①The use of supporting aluminum guide rails specially designed for installing crystalline silicon modules makes it very convenient to install and fix solar modules and reduce installation time;
② Columns, beams and other load-bearing parts have been strengthened design to meet the requirements of large working loads;
③The wiring groove is integrated on the beam to make the construction more convenient.
4. Tracking bracket form
Single axis tracking
A tracking system that rotates around a one-dimensional axis so that the plane of the photovoltaic module is as vertically incident as possible by the sun.
Flat single axis tracking system
Oblique single axis tracking system
Structural features:
1. Self-balancing structure reduces mechanical wear and extends the life of the motor;
2. Driven by a slewing bearing reducer, no gap;
3. Simple structure, easy to install and maintain;
4. The fragile and consumable parts are made into standard products, and the motor is easy to maintain and replace.
Features of the control part:
1. Adjacent systems have no shadow occlusion during the whole tracking process;
2. The tracking system has a self-return function at night;
3. Use time control method according to the sun's trajectory;
4. It has the protection function of strong wind and heavy snow to improve the safety performance of the power station;
5. With network monitoring function, realize centralized control, suitable for large power stations.
Dual axis tracking
According to the control mode, the dual-axis tracking system can be divided into time control type and light control type.
According to the geographical location and local time, the incident angle of sunlight is calculated in real time, and the photovoltaic module is adjusted to the specified angle through the control system, which is also called astronomical control mode or clock control mode.
The incident angle of the sunlight is measured by the sensing device, thereby controlling the rotation of the photovoltaic module and tracking the incident angle of the sunlight, which is also called the light sensing control method.
Mechanical part:
1. Non-eccentric structure: The center of gravity of the grid coincides with the axis of the mechanical structure, maintaining the balance of positive and negative torque, reducing motor power consumption, and prolonging the service life of the machine and motor;
2. Weightlifting structure: reduce the vibration of the grid under the running state and improve the wind resistance;
3. Two sets of slewing bearings: good torque resistance and stable system.
Control section:
1. Automatic time-controlled tracking based on the astronomical algorithm of the sun's trajectory, with high tracking accuracy, and not affected by external environments such as weather;
2. Standard industrial plug, with anti-error insertion and reverse insertion function, easy to install;
3. All external interfaces adopt photoelectric isolation measures, with strong anti-interference ability and stable operation;
4. The industrial communication interface can easily form a monitoring network and realize the function of centralized control.
Common roof bracket forms
1. Flat roof mounting structures
The flat roof installation system is suitable for outdoor or flat roof load situations.
Basic
Basic flat roof fixing bracket
Features:
1. Suitable for crystalline silicon components and some thin film components of any specification;
2. Embedded anchor bolts on the installation surface, or similar cement foundation;
3. Design the installation angle according to actual needs.
Ballasted roof top solar mounting
Ballast flat roof fixing bracket
Features:
1. No damage to the original waterproof layer, no need for waterproofing;
2. Suitable for crystalline silicon components and some thin film components of any specification;
3. An adjustable load frame is installed on the bottom frame, and cement blocks, stones, etc. are placed on it;
4. Design the installation angle according to actual needs.
Deflector type
Deflector type flat roof fixing bracket
Features:
1. Suitable for flat roofs with small loads;
2. The component installation slope is 10-15°;
3. The deflector material uses stainless steel or aluminum-magnesium-zinc plate;
4. No damage to the original roof, no need to worry about water leakage.
Color steel tile roof installation system
Color steel plate roofs are usually installed in non-penetrating ways such as buckles, concealed buckles, and overlocking. In special cases, they can be installed through penetration.
First understand what is a color steel roof: thin steel plate formed by cold pressing or cold rolling. The steel plate adopts organic coating thin steel plate (or color steel plate), galvanized thin steel plate, anti-corrosion thin steel plate (including asbestos asphalt layer) or other thin steel plates.
Color steel profiled tile
Angular
Common color steel tile fixing seat assembly
Installation Precautions
1. First, repair the roof with wooden or bamboo construction plank roads to avoid direct stepping on the roof slab during the secondary transportation of materials, which will cause the roof slab to deform, and the sealant will come off and leak water;
2. Clear the position of the original structure roof purlin, and mark the specific position with the elastic ink line; the connection between the bracket and the color steel plate must be at the roof purlin position;
3. When walking on the roof, the construction personnel must wear insulated soft-soled shoes and walk through the troughs. The sundries on the roof panel must be removed every day to prevent rust and scratches on the roof panel;
4. There must be no omissions in all locations where sealing paste needs to be laid. After installing the outer roof panel, remove all the debris and iron filings on the roof. If the roof panel coating is found to be scratched, it must be repaired with a color board special repair paint. If the rivets and self-tapping screws are empty, they should be filled with rivets and sealing paste at any time, and the rubber gaskets should not be damaged.
