1, the former language
The lack of motivation has become a drawing issue today. At the 1979 United Nations Conference on the Promotion of Science in Vienna, motivation was listed as one of the four major problems faced by humans: food, population, and the environment. At present, China’s economy is undergoing a period of rapid development, and the demand for power is also growing rapidly. The contradiction between urban and rural construction and power supply and demand is outstanding. In particular, the construction and housing industries in the field of construction are large power consumers. How to deal with power is not a problem. For now, saving power is the primary task of handling the current international power. The construction of energy conservation has become an important part of the national energy conservation strategy. The construction of energy conservation includes the construction of new energy-saving and existing energy-saving reconstruction. The real large-scale construction of energy-consuming buildings is due to the existing construction. Because the number of existing buildings is very large, and most of the existing buildings do not have any energy-saving measures, their thermal insulation functions are poor, and the power of the equipment system is low, resulting in the adoption of warm cooling energy. Spending is grim. Most of the new construction projects have reached the goal of energy conservation through the efforts of the state in recent years, and some regions have begun implementing energy conservation programs. Therefore, the construction of energy-saving reforms is the key to building energy-saving in China. If only considering the energy conservation of newly-built constructions in this respect and not considering the existing reconstruction of energy-saving projects, the actual effect of building energy-saving projects can only be limited to a small extent. Therefore, it is imperative to strengthen the research and development of existing energy-saving projects.
2. Existing construction status
It is relatively easy to build a new country to build a national energy conservation code. If the planning plan fails to meet the requirements, the relevant department will not approve it. The existing buildings, because of their different ages, and different structural systems, are different in terms of transformation, involve many elements, and are difficult to implement in energy conservation. Therefore, it is necessary to increase investment in all aspects. In addition, most of the existing facilities have poor insulation and thermal insulation functions, and the power of the equipment system is low, resulting in serious waste of heating and cooling energy. The main points of the existing energy-saving reconstruction are to improve the insulation and heat insulation function of the building envelope structure, reduce the power consumption required for constructing heating and cooling, and then make the construction energy consumption reach the national energy conservation norms. Therefore, for the existing energy-saving reconstruction, it is necessary to carry out a comprehensive energy-saving reform of the external protection structure and heating system of the building. Existing construction now has the following primary issues.
3, the principle of energy conservation of glass curtain wall
At the time of construction and construction, the use of glass curtain walls has now become an ongoing trend in the modern construction industry. People use glass curtain walls during the construction of construction mainly because of its energy-saving function. Glass is a clear source of information. It enables the transfer of heat, primarily through convection, radiation, and conduction. In addition to these three methods, the heat transfer time of the glass can also be achieved through the direct transmission of sunlight. In order to better evaluate the progress of the energy transfer of glass, people can determine the number of transmission joules per unit area, unit temperature difference, and unit time. The greater the number of joules, the more energy loss of the glass is proved, and the energy saving is particularly devious. In order to better test the energy saving effect of the glass curtain wall, it can also be studied through the concealment coefficient. Under the same conditions, the glass components and the bright glass are placed under the sunlight, so that the solar radiation energy passes through the ratio of the radiant energy. To determine the concealment coefficient, the smaller the concealment coefficient, the better the effect of clarification of energy conservation. When the sun shines through the glass to the room, part of it can pass directly, and the other part will be absorbed by the glass curtain wall and then converted into heat energy. This part of the heat energy will directly enter the room. This will add heat to the house, which will increase the temperature in the room.
4. Problems and Causes of Building a Glass Curtain Wall
4.1 The glass curtain wall has a certain modernity and sense of the times, and the shape and color of the glass curtain wall can be changed at will, so that the architects like to use the glass curtain wall to add the beauty of the building. However, the power of the glass curtain wall in the construction of the project has also been plagued with certain degree of trouble for our country. China is a power-consuming country, and the rapid consumption of power has prevented the country's economic construction from proceeding. Now, in the cities of our country, the power consumed by construction accounts for a quarter of the overall power consumption, and the cost of public construction power accounts for most of the construction total power consumption. China's glass curtain wall is generally built in public construction, and the glass curtain wall can not be a good use of light resources. In the summer, the amount of heat captured by the glass curtain wall due to high solar radiation also increases. At the time of winter, due to the relatively low outdoor temperature, the speed of heat dissipation from the glass curtain wall is accelerated, thus forcing air conditioning in winter and summer. The increase in the number of applications has caused a lot of energy consumption in our country.
4.2 Now that glass curtain walls in the city are everywhere, although the image of the city has been beautified to a certain extent, certain light pollution has also occurred. The glass curtain wall itself has a reflection effect on the light, which affects the safe travel of the vehicle on the road. The second is that when the glass curtain wall reflects light for a long time, people will have a certain influence on the vision when they look at the white light reflected by the reflection. Together they will also cause people's certain diseases and affect people's mood. In some wealthy metropolises, local city managers constantly receive public complaints about light pollution.
4.3 After a prolonged period of rain and wind, as well as prolonged exposure to sunlight, the glass curtain wall continued to degrade the safety and quality of the glass curtain wall. As a result, in some areas such as Shanghai, there have been a number of incidents in which curtain wall glass bursts and falls. The beauty of the glass curtain wall has not attracted the public's sense of affection. On the contrary, it is to avoid the glass curtain wall. Glass walls, such as time bombs, will be blasted on the head of the public at any time. Even if the planned service life of the glass curtain wall does not exceed 25 years, the energy consumption and safety hazards of the glass curtain wall will be in an embarrassing situation.
4.4 The problems with glass curtain walls are almost always due to data problems. The primary data for the construction of glass curtain walls is glass materials. As the primary external protection part, the function of glass directly influences the quality of glass curtain walls. After our country has drawn up new energy-saving norms, some glass curtain wall skills have not reached the new energy-saving norms.
4.5 In the process of creating a glass curtain wall, it is very important to seal the glass as a sealing material, and the length of the weatherproof application of the sealing material will have a certain influence on the length of the application of the glass curtain wall. When investigators investigated the glass walls of some cities, it was found that some of the sealing materials for the jointed glass have now presented a series of problems, such as cracking and damage to the steel. The presentation of these phenomena has had a certain impact on the construction of the indoor environment, and has also caused a lot of power consumption.
5, according to the existing energy-saving renovation methods to build glass curtain wall
5.1 When building a glass curtain wall, it is possible to construct a double-layered curtain wall. The establishment of a double-layered curtain wall is based primarily on the use of the “chimney effect” phenomenon in Xiadi. The double-breathing curtain wall enables natural ventilation, which has a beneficial effect on the temperature of the room; together, the glass is built. In the curtain wall, a semi-bright shutter can be installed. In the summer when the sunlight is strong, the roller blind can be put down. The roller blind has a certain shelter and reflection effect, and can effectively eliminate most of the sunlight, so that it can be built down. The temperature in the room reduces the number of times the air conditioner is used due to cooling, which promotes the intention of saving power in our country. During the winter season, the outer curtain wall vents of the double-layer respiratory curtain wall can be closed. As a result, the interior of the curtain wall gradually increases in temperature after exposure to sunlight for a long period of time. Since the vents are closed, the heat is hard to be consumed. To a certain extent, the temperature difference between the indoor and outdoor is reduced. Together, the indoor temperature is no longer transmitted to the outdoor, which has a certain effect of insulation. The use of double-glazed curtain walls provides a good sound insulation effect. The sound insulation effect of the double-glazed curtain wall is very strong. In the air sandwich between the glass, the sound insulation function of the glass curtain wall is surely prevented and improved. In some cities, the noise pollution is very serious. Because the construction of these cities can not be very good for window ventilation, and in this environment, the choice of double glass curtain wall is a best choice.
5.2 In the glass curtain wall, the lighting of the sun is also the most important issue in the demand handling. Therefore, the glass curtain wall must be subject to certain shade protection skills. In some areas that are hot in summer and cold in winter, they are now widely used to build shading skills. Shading skill is a very important energy-saving skill. It can reflect or absorb solar heat in time. It has a certain control effect on the temperature of the room. It can improve indoor comfort to a certain extent and also reduce the cost of air conditioning. The motivation. In the glass curtain wall, the first application of the shading skill is to use the horizontal shading skill. Over the course of a year, the height and orientation of the Sun are continuously changing and circulating. This requires planners to plan according to actual conditions. At the maximum height of the sun, the horizontal sunshade can effectively block the sunlight that is projected; together, during the winter season, sunlight can be introduced into the room at the maximum limit. The second option is vertical shading. The vertical shading is suitable for the construction of the northeast and northwest directions, which can block the oblique fiber; the third is the integrated shading, which has a very good concealment effect on the sun in all directions of construction; The baffle-type sunshade is used in the east-west direction and is a very sunny area. However, it will have a certain influence on people's vision and indoor ventilation. The final result is the blind room shade, which can be based on people's needs. Various angles of conditioning, shade and lighting ventilation have a certain promotion effect.
6, material aspects
Choose heat-reflecting Low-E glass, hollow glass and so on. These glasses have been produced in the country for a long time. They are only expensive, so they have been used less frequently in glass curtain wall projects. For example, the use of insulating glass made of heat-reflecting glass and bright glass is better than a brick-walled brick wall. The use of aluminum-plastic composite materials, insulation profiles do curtain wall beams and columns. In the selection of heat-insulating aluminium profiles, PUR data should be used for heat insulation data if it is selected for production by a pleating technique. Other existing curtain wall glass films can also be used to reduce energy consumption. The thermal insulation film on the market can save energy by more than 15%.
7, structural aspects
The use of shading facilities such as louvers, grilles, sunshades, etc., can maximize the limit to reduce the direct sunlight, prevent indoor overheating, and then reach a better thermal insulation effect. The sunshade shutters have horizontal shutters and vertical shutters, with manual control, electric and adjustable shutter systems. According to the construction style and requirements, different types of shading systems can be used.
The ventilation curtain wall composed of two glass curtain walls is also called a double curtain wall, a breather curtain wall, and a hot aisle curtain wall. A ventilation and ventilation layer is formed between the two walls of the table. Due to the circulation or circulation effect of the air in the ventilation layer, the temperature of the inner wall closes to the indoor temperature and the temperature difference is reduced. It saves power when compared with the traditional curtain wall heating. 42%-52%, saving power 38%-60% when cooling.
The intelligent curtain wall is an extension of the ventilated curtain wall. It is based on the intelligent construction and moderately controls the construction of matching skills (warm, hot, light, and electricity). It is useful for conditioning indoor air, temperature, and light through the computer. 30% of traditional curtain walls.
The basic unit of the photovoltaic curtain wall is a photovoltaic panel. The photovoltaic panel is a battery array composed of several photovoltaic cells in series and in parallel. The battery array is placed in two layers of glass (the upper layer is a bright glass, and the base layer color is beautiful). The resin is thermoset, and the junction box and wires on the back side of the photovoltaic panel allow solar energy to be converted into electricity for use by people. Under normal circumstances, this type of curtain wall columns and beams use insulated aluminum profiles.
At the present stage in our country, the priority is to use energy-saving skills that are commensurate with the level of economic development. We must not unilaterally pursue the principle of low energy consumption regardless of economic costs. Together, we attach importance to the research and development of renewable natural energy technologies such as solar energy, wind energy, and geothermal energy, and reduce the use of renewable energy. We will gradually expand the use of large cities and economically developed regions throughout the country and complete our country's established guidelines for energy conservation.