What is photovoltaic glass
Crystalline silicon solar cells have poor mechanical strength and are prone to rupture. The moisture and corrosive gases in the air will gradually oxidize and corrode the electrodes, making them unable to withstand the harsh conditions of outdoor work. Therefore, solar cells are usually encapsulated by photovoltaic glass via EVA and back panel.The photovoltaic glass in the photovoltaic module to protect the battery from water gas erosion, block oxygen to prevent oxidation, high and low temperature resistance, good insulation and aging resistance.Photovoltaic glass is a kind of silicate glass with low iron content, also known as ultra-white embossed glass.
The photovoltaic glass used in crystalline silicon cells is different from float glass. The upper surface of the photovoltaic glass is suede, so that the light directly to the surface of the module is not easy to produce mirror reflection. The lower surface is embossed surface, which can enhance the adhesion force with EVA film.
The main raw materials of photovoltaic glass include quartz sand, soda ash, limestone, dolomite, sodium nitrate, mirabilite, sodium pyroantimonate, aluminum hydroxide and so on.Quartz sand mainly plays the role of network forming body, the dosage usually occupies the majority of glass components, soda ash is mainly used to provide sodium oxide, mainly to reduce the melting temperature of glass;The main function of limestone is to adjust the viscosity of the glass to the appropriate value, so that the glass molding time to meet the molding requirements, the role of mirabilite is mainly as a clarifying agent, used to remove bubbles in the glass, to provide glass transmittance.
Photovoltaic glass raw material consumption ratio
01 preparation process of photovoltaic glass photovoltaic glass is usually prepared by the calendering method, in which the production process can be divided into two stages: raw sheet production and deep processing;The raw material production mainly includes batching, melting, rolling, annealing and cutting.Around 1100 ℃ in the rolling process, the molten glass, a calender rollers rolling and cooling, to a certain speed reaches a certain thickness, a certain width, a certain pattern, through the glass of a rate of 91.5%, and then after annealing lehr, make the glass has a relatively stable stress curve, to have a certain strength, not easy broken, is conducive to cutting, processing glass.It should be pointed out that photovoltaic embossed glass and float glass production lines are different, if the demand for photovoltaic glass is not enough to directly switch from the float glass production line.
Deep processing process is usually the original glass coating and toughening, coating is to improve the transmittance of photovoltaic glass, toughening is to increase the mechanical properties of glass, after toughening the bending strength of glass is ordinary glass 3~5 times, impact strength is ordinary glass 5~10 times, improve the strength and also improve the security.
Photovoltaic glass process flow
The performance of photovoltaic glass requires that photovoltaic glass must have good light transmittance. Generally speaking, the light transmittance of uncoated steel (wavelength range from 380nm to 1100nm) is usually above 91%, while that of coated glass after deep processing can reach 93.5%.In addition, photovoltaic glass needs to meet certain weather resistance and mechanical properties. According to GB T 30984.1-2015 solar glass — part 1 ultra-white embossed glass, the minimum performance of photovoltaic glass for photovoltaic modules should meet the following requirements.
China’s photovoltaic glass industry
Photovoltaic glass industry barriers is higher, the concentration is higher, the production need long-term accumulation of experience and one-stop production process, and need a larger initial investment, the capacity of 900 tons/day photovoltaic glass kiln need initial investment RMB 9, 550 tons of stove investment takes about 3-400 million yuan, and large kiln had lower manufacturing cost compared with ordinary kiln (low energy consumption to 20%). As a result, photovoltaic glass industry has obvious scale effect, and the large amount of molten core technology mainly in the hands of leading enterprises,Smes are relatively lack of technical strength and economic strength to build 1000 tons of daily melting capacity kilns.
Post time: Dec-13-2019