Polaris solar PV net news: in recent years, photovoltaic industry has developed rapidly in China, but recently under siege from developed countries in Europe and America, has been struggling, but to turn to the domestic market. Only the introduction of new ideas, new designs, new materials for domestic users with a safe, economical, reliable and versatile steel framework can provide comprehensive promotion and development of photovoltaic power generation in the country providing more space.
Introduction: with the rapid development of green economy, Mono/polycrystalline silicon photovoltaic and thin film BIPV technology matures. Compared with other structures of steel structures, functionality, design, construction, and has a huge cost advantage. Therefore, development and production of new types of steel mounting system replacing the existing angle steel frame system is of great significance.
1, solar steel for steel support types
Since the photovoltaic characteristics of simple structure, small size, mostly light in use steel structural steel and ordinary steel with small section steel.
Light structural steel: light steel structure mainly refers to the small bar, angle iron and steel. Among them, the angles when used as a supporting Member, can better leverage the strength of steel, and benefit the whole bracket installation, but when used as flexural and compressive members, produces relatively large deformation. At present, the angle relative to the solar bracket GB, optional type is not much, so more small angle models are needed to adapt to the fast-growing solar market at present. Thin-wall section steel Purlin members, generally made of thick-walled 1.5-5mm of thin steel plate, cold-formed or cold-rolled back into a variety of different types and sizes of sectional steel products. Compared with the hot-rolled steel sections, in the case of the same cross-sectional area, thin-walled beam radius of gyration can increase becomes prohibitive, section moment of inertia and resistance to torque can be increased by 0.5-3 times, thus more rational use of the strength of the material, but most of the steel processing in factories, requiring high precision screw holes drilled and PV panels after the match. After factory rhinestone buckle can be hot-dipped galvanized rust-proof; delivery to site installation, due to the small steel section, tools to operate, construction more difficult. Most of the panels are currently unable to connect directly and thin-walled beam installation, requires other auxiliary structure (such as blocks, and so on).
Ordinary steel steel:
Smelting of common structural steel used is easy, low-cost carbon steel or low-alloy steel, section has many types of PV commonly used include I-, h-, l-, and various design requirements of the special section. Processing methods are also varied, with welded steel is a selection of different thickness steel plates, welded steel processing at the factory according to design requirements, this molded PV projects in different parts of the calculation, in different parts of different thickness steel plate than hot forming products have become more reasonable, more suitable for installation on site, you can also save steel.
2, performance requirements of solar mounting system for steel steel steel should have the following properties:
1) tensile strength and yield point. High yield point steel beams can be reduced, reduce structural weight, save steel and reduce overall project costs. High tensile strength can increase the overall safety of structures, improve the reliability of structures.
2), plasticity, toughness and fatigue resistance. Better plastic structures have a large deformation before failure can be, thereby enabling people to discover and take remedial measures. Better plastic can also adjust the local peak stress, solar panel installation in itself regularly in order to adjust the angle, using forced installation, and incur redistribution of plastic can make, stress concentration of certain parts of the structures and components of more uniform stress, improve the overall bearing capacity of the structure. Good toughness can enable structure under external impact loads when destroyed absorb more energy, particularly wind large desert plant and roof plant and wind-induced effects are obvious, the toughness of the steel can reduce the degree of risk. Better fatigue resistance can also lead to structure has a strong wind against alternating repeated load capacity.
3) processing performance. Good machining properties including cold workability, hot workability and weldability. Photovoltaic steel structure the steel used not only structures and components to be easily processed into a variety of forms, and require these structures and components are not caused by the processing strength, ductility, toughness and resistance to adverse effects of excessive fatigue.
4) life. Because solar PV system design service life of 20 years or more, and good corrosion resistance is an important indicator to measure support system. If the bracket short life, is bound to affect the stability of the whole structure, leading to economic benefits of extending the payback period decreases the overall project.
5), subject to the above conditions, photovoltaic steels for steel structures should also be easy to purchase, production, and prices cheap.
3, the new solar steel supporting frame for technical analysis
Current conditions of use angle mounting is more and more, the main reason is the uneven quality of steel, installation requires a lot of drilling, drill steel and prone to rust, so you need to use a new type of stent to replace those angle brackets in order to slow down corrosion, prolonging service life of purpose.
New solar bracket body structure: 1) special cold-formed section steel support structure. Shaped-cold-formed steel framing is a mass production manufacturing, can be assembled quickly and completely dry operation assembling light steel structure system, has less amount of steel, construction saves time, labor, and other characteristics. The major manufacturers such as xilide, Khammah. Special-shaped cold-formed thin-walled steel structure system of steel supporting frame is factory made of cold-formed thin-walled steel sections bolted structural skeleton formed at the construction site, then install the battery on board to form a PV array as a whole. 2) factory prefabricated monolithic steel support system. Prefabrication Purlin of steel structure frame at the construction site just assembled on site fixing bracket module, then install the panels that form the whole photovoltaic arrays, fast construction, suitable for large-scale power stations. This steel bracket installation requires very high, generally uses the best quality steel, surface treatment is excellent, and the need for early and PV module manufacturers fully communicate to achieve the perfect Assembly tie.
3) beam-column frame-wall mounting system. Suitable beam-column frame-steel supporting frame for PV curtain wall system. The structure of light weight, reliable structure, because of its small lateral stiffness, when height or high-storey high and sets lateral support needed to form a braced-frame structure. Top PV curtain wall design, commonly used with in-situ concrete mixed structure of embedded parts of steel structures, and enhance the overall structure of the lateral capacity, reducing the amount of steel, thereby minimizing total cost.
4, new type of cold-formed thin-wall mounting components installed:
1) steel members connected by new type of cold-formed thin-wall mounting system connect prefabricated piece of steel plastic composite was assembled by, these steel plastic composite connectors type variety, can be adapted to different installation conditions, correctly choosing the mixed member connection and is an important part of overall structure.
2) bracket with the underlying connection is new type of cold-formed thin-wall mounting a lesser weight and put more holes. Generally dominated by independent Foundation and, if necessary, subject to reinforced concrete coupling beams. For the poor geological conditions at places, strip or cross bases could be used, as far as possible without using the raft. All the upper column use articulated form, and embedded parts, part-you can choose to insert a column, and embedded bolts or outer waterproofing of concrete. This simple two column forms are processed, convenience and even better performance.
3) bracket Purlin connections installation node connections takes three forms: rigid, hinged and semi-rigid jointed, the three connection methods are available for ready matching nodes of modular production methods. Hinged construction, manufacture and installation of the most convenient, but windy area you need to set horizontal bracing or raking wall subjected to horizontal loads and provides extra stiffness, do not set the support beam and column connection nodes should do the test. Semi-rigid connections than just the connection construction is simple, well articulated performance, by their force to be controlled, needs experience to actually use, and is mostly not used. Both ends of the connection typically hinged bolts first, then a field weld.
5, concluding remarks
Relatively, new cold bent thin-walled steel type bracket structure system can makes project duration substantially reduced, meet has solar PV building of needs, especially its superior of anti-corrosion sex, and can recycling sex, reflected has steel of integrated cost advantage; new cold bent thin-walled type structure solar bracket system of directly economic main from structure construction duration shortened and maintenance costs reduced of advantage, and with using years number of extended, benefits increased more obviously. I believe that developing new type of cold-formed thin-walled steel structure system is an inevitable trend.
Original title: solar mounting system you choose? How to use it?