Symbiotic relationship between curtain wall of the

The symbiotic relationship between building curtain wall and glass industry

China's building curtain wall started in 1978. After nearly 30 years of development, by the beginning of the 21st century, China has developed into a domestic raw material enterprise in the world, which needs to improve the following aspects: leading the country in curtain wall production and use. In the first 10 years of the 21st century (2001-2010), China's building curtain walls continued to develop rapidly. The development of building curtain wall in China is inseparable from the development of building glass in China. Building curtain wall and building glass develop synchronously, and they support and depend on each other

1。 The artistic effect of architectural curtain wall depends on the development of new architectural glass. The 1980s was the initial stage of building curtain walls, and there were not many varieties of building glass. It was fashionable to use colored glass (tea glass, blue glass, green glass). Later, people had higher and higher requirements for the appearance of buildings. Especially with the rise of hidden frame glass curtain walls, coated glass made the hidden frame glass curtain walls dazzling, and the hidden frame glass curtain walls were favored by architects and people and developed rapidly

2。 Building glass has developed from building components to structural components. The development of tempered glass, laminated glass and tempered laminated glass has brought the development of building curtain walls into a new era. Because these glasses have high mechanical properties, they can be used as materials for structural components. At this time, glass can be used not only as a light transmission panel supported on four sides, but also as a light transmission panel for point supporting glass curtain walls, that is, holes are opened at the four corners of the glass, and the glass is fixed on the steel claws with connectors to become a point supported glass curtain wall, Pressing plates can also be set on the glass joints or four corners to fix the glass panel on the steel cable to form a single-layer cable (single-layer vertical cable) glass curtain wall. Glass is the material of the beam. Glass beam glued full glass curtain wall and point supported glass beam full glass curtain wall have become the darling of the public building lobby, making the glass beam glass curtain wall and point supported glass curtain wall extraordinary development. In 2006, the glass beam (including point supported) glass curtain wall reached 2.2 million square meters, and there was also a 5-6 meter cantilever full glass canopy. All glass stairs are made of glass, including stair landing beams, platform plates, stair Inclined Beams and step plates. The stair platform beam and the floor beam on which the stairs are installed are suspended with steel cables, the inclined beam of the stairs is fixed on the floor beam and the platform beam with connectors (connecting and descending cost parts), the platform plate is fixed on the platform beam with connectors (connecting parts), and the step plate is also fixed on the inclined beam of the stairs with connectors (connecting parts), so as to form a fully transparent stair system. The all glass floor is that the floor beams and floors are all made of glass materials. The glass floor beam is supported on the main structure, and the glass floor is fixed on the glass floor beam with connectors (connectors). CCTV, which won the top ten best buildings in the world in 2007, used nearly 1000 square meters of glass floor. Standing on the glass floor of CCTV sightseeing floor, looking down at the panoramic view of Beijing, there is a feeling similar to looking at the earth from "Shenzhou V" and "Shenzhou VI"

3。 The development of insulating glass and Low-E insulating glass has brought the energy conservation of buildings with glass curtain walls to a new stage. The release of gb50189 and other energy-saving design codes puts forward strict requirements for building energy conservation. Building curtain walls, supported by the development of hollow glass, Low-E hollow glass (and vacuum glass), not only have not stopped the pace of development, but also stride forward on a new platform

4。 With the development of glass hot bending technology, all kinds of special-shaped buildings in China are covered with the coat of building curtain wall. For example, the horn shape of Beijing Planetarium can be realized

5。 Building curtain walls are constantly affected and polluted by the external environment in the process of use. In the past, they were cleaned by window cleaners and spiders. The emergence of self-cleaning glass has opened up a new way out

with the continuous development of China's construction industry, new requirements are put forward for building curtain walls and building glass. This is a new task for technicians in China's building curtain walls and building glass industry. We should dare and be good at accepting this challenge and develop better and more building glass:

first, develop glass with diverse artistic forms and colorful colors to meet the needs of various architectural decoration. With the development of economy and the improvement of technology, people's living standards have also improved. People have more and more diversified requirements for the functions, colors and tones of buildings. For example, only transparent and colorless glass curtain walls can not meet the requirements. Transparent glass curtain walls are only suitable for displaying their internal images, such as large department stores

however, it is not suitable to show its internal structure and activities on some occasions. The unidirectional transparency of coated glass makes it impossible to see the interior from the outside, but the exterior can be seen clearly from the interior. The hidden frame glass curtain wall integrates the specific texture and brilliance, as well as the transmission, reflection and refraction of light. When the light shines on the large-area hidden frame curtain wall, because the glass has the similar property with light, it can create the strange effect of light art. Coated glass has the characteristics of a mirror on the face of light, and as transparent as ordinary glass on the back light. This magical characteristic creates a variety of possibilities for visual appreciation

second, develop high-strength glass varieties and promote the development of all glass structure. Although glass can be used as a structural member in buildings, its strength is still low compared with other metal materials. In this way, the structural section is much larger than metal materials, and the material consumption is large, the section is large, and the occupied space is large, which affects the building space. This requires the development of glass with higher strength and better stability as structural members, so that the glass structure is lighter, the occupied building space is reduced, and the building is more beautiful, The utilization of architectural space is more economical and reasonable

Third, develop more energy-saving glass products to promote the progress of building energy conservation in China

requirements for curtain wall energy conservation: maximize the use of natural energy for heating in winter, obtain more heat and reduce heat loss; In summer, heat gain is minimized and natural energy is used to cool down, so as to achieve the purpose of energy conservation

due to the vast territory of our country and the great climate difference between the south, North and East and West, the influence of transparent curtain wall on building energy consumption mainly has two aspects: on the one hand, the thermal performance of transparent curtain wall affects the indoor and outdoor temperature difference heat transfer of heating in winter and air conditioning in summer; In addition, it is the heat gain inside the building caused by the influence of solar radiation on the transparent materials (such as glass) of the curtain wall. In winter, the solar radiation entering the room through the transparent curtain wall is conducive to building energy conservation. Therefore, reducing the heat transfer coefficient of the transparent curtain wall and suppressing the temperature difference heat transfer is one of the main ways to reduce the heat loss of the transparent curtain wall; In summer, the solar radiation entering the room through the transparent curtain wall becomes the cooling load of the air conditioner. Therefore, reducing the solar radiation entering the room and reducing the temperature difference and heat transfer of the transparent curtain wall are the ways to reduce the energy consumption of the air conditioner. Due to the complex changes of solar radiation in different latitudes and directions, the daily radiation intensity and peak time are different. Therefore, the energy-saving design of heat channel curtain wall in different latitudes should also be different. In the severe middle cold area, the heat loss of indoor and outdoor temperature difference heat transfer during the heating period is dominant. Therefore, the requirements for the heat transfer coefficient of curtain walls are higher than those in the south. In hot summer and warm winter and hot summer and cold winter areas, the load caused by solar radiation during air conditioning may become the main contradiction. Therefore, the requirements for the shading coefficient of the glass (or other transparent materials) of the curtain wall are higher than those in northern areas

on the other hand, in order to make the building adapt to different climatic conditions around the country and meet the energy-saving requirements, the reasonable thermal performance parameters of the building envelope should be determined according to the building climate zoning where the building is located. The winter cold protection and insulation of buildings are mainly considered in the cold and freezing regions in the north. The heat transfer coefficient of building envelope has a great impact on the heating energy consumption of buildings. Therefore, the limit value of heat transfer coefficient of enclosure structure is required to be higher in severe cold and severe cold areas. Hot summer and cold winter areas should not only meet the thermal insulation in winter, but also consider the thermal insulation in summer. Unlike northern heating buildings, one-way heat transfer process is mainly considered. In hot summer and warm winter areas, Ma Kai, vice premier of the State Council, who mainly considers buildings, organized a symposium on Accelerating Railway Construction around the country. In summer, heat insulation, solar radiation has a great impact on building energy consumption. The heat of solar radiation entering the room through the curtain wall is the main cause of indoor overheating in summer. At the same time, we should also consider the two-way transmission of building heat and humidity process under natural ventilation conditions. We cannot simply reduce the heat transfer coefficient of walls, roofs and windows and increase the thickness of thermal insulation materials to achieve the purpose of saving energy consumption. Therefore, the limit requirements of heat transfer coefficient of enclosure structure are also different. Glass varieties that meet different energy-saving requirements should be developed

fourth, in order to meet the needs of photoelectric curtain wall (laminated surface), it is necessary to develop glass with high rigidity, because the silicon wafer is fragile, and the requirements for glass deflection are very strict. Solar photovoltaic curtain wall is a device that converts solar energy into electric energy. In the current situation of tight energy supply, it provides an unprecedented opportunity for the development of solar photovoltaic curtain wall. However, the photovoltaic panel used for manufacturing the solar photovoltaic curtain wall is formed by clamping a thin silicon wafer between two pieces of glass, so glass is the main clamping material for manufacturing the solar photovoltaic curtain wall panel. Because the silicon wafer is extremely fragile, it will break if it is bent slightly larger, so it is required that the glass holding the silicon wafer has better stiffness than ordinary glass

therefore, it is necessary to produce glass with greater stiffness than ordinary glass to meet the needs of the development of photoelectric curtain walls. At the same time, the transmittance of solar radiation also affects the effect of solar photovoltaic power generation. Therefore, the glass used for photoelectric curtain wall panels is required to have a high transmittance and strong self purification ability. Once the glass surface is polluted, it will affect the solar radiation received by silicon wafers, and make the photoelectric panels on the roof easier to accumulate dust, It affects the solar radiation received by the silicon wafer, so the glass used to make photoelectric curtain wall panels requires high rigidity, high light transmittance and good self purification ability