Today, with the growth of the population and the improvement of people's living standards, the energy consumption of buildings is also rising sharply, especially in low temperature areas. After years of research and practice, the application of solar energy in architecture has made gratifying progress.
There are three ways to apply solar technology in buildings.
1.Passive solar house
Passive solar houses are one of the most widely used types of solar buildings at home and abroad. The advantages are simple structure, low cost and convenient construction. In low-temperature areas, coal resources are scarce, but solar energy resources are abundant, and climatic conditions are superior, especially during the heating season, with less rainy days and dry weather, making passive solar houses widely used.
The core component of the passive solar house is the collector wall on the south side of the house, also known as the "Trombe" wall, which consists of a light-transmissive glass, a heat collecting plate and a heat collecting wall (brick wall). A tuyere is provided at an appropriate position on the upper and lower portions of the heat collecting wall.
The working principle is that the sunlight is irradiated onto the heat collecting plate through the glass, the heat collecting plate is heated, and a part of the heat is accumulated in the heat collecting wall. When the upper and lower air outlets are opened, the cold air of the room enters the cavity between the heat collecting plate and the wall through the lower air outlet, is heated in the cavity, and then returns to the room from the upper air outlet.
This recurring thermal cycle process increases the room temperature. When it is hot, you can adjust the indoor temperature by controlling the opening and closing of the tuyere gate so that the indoor temperature is not too high. The two sides, the back and the roof and the subfloor of the house are designed according to the insulation and energy saving requirements.
2. Active solar house
It is a solar heating system composed of a solar collector and a fan, a pump, a radiator, or a solar air conditioner and a heating system composed of an absorption chiller. Solar collectors are a key component of active solar systems. Depending on the needs, solar collectors can be used to make different systems, either to provide hot water for civil or public buildings, or to provide heating or air conditioning for these buildings. Therefore, the application of solar collectors is extremely important for building energy efficiency. Solar collectors can be divided into two types: flat plate collectors and vacuum tube collectors. At present, flat plate collectors and vacuum tube collectors have been widely used in solar water heating systems; vacuum tube collectors have begun to be used in solar heating and solar air conditioning systems for buildings.
2.1 Solar water heating system
Solar water heating systems generally include a solar collector group, a water storage tank, a circulation pump, a photosensitive probe, an electric control cabinet, and a pipeline. According to its operation mode, the solar water heating system can be divided into natural circulation type, forced circulation type and DC constant temperature discharge type.
2.2 Solar heating system
In low temperature buildings, heating is required in winter, and solar heating systems are a further development of solar water heating systems. In fact, solar heating systems can often be used in conjunction with solar water heating systems. In this case, on the one hand, it is necessary to appropriately increase the lighting area of the solar collector: on the other hand, since the heating is required in the cold season, an antifreeze or antifreeze vacuum tube collector is used.
2.3 Solar air conditioning system
Solar air conditioners are generally implemented by combining solar collectors with absorption or adsorption chillers.
3 Solar photovoltaic technology
Solar photovoltaic technology converts light energy directly into electrical energy through solar cells. Solar cells can be combined into high-power components that can be combined into solar power plants for different power applications. Solar photovoltaic systems typically include a battery pack, energy storage, inverter, and control sections. Applications in buildings can be divided into independent photovoltaic systems and grid-connected photovoltaic systems. The application of solar cells provides electricity for lighting such as buildings. If solar energy can fully meet the energy needs of buildings, it can be called "zero-energy houses."
The future development trend is the integration of building solar energy. It refers to the modern building with energy-saving and environmental protection features by combining solar energy technology and solar air-conditioning technology, combining solar energy materials with building materials.
Fully developing and utilizing solar energy and building solar energy buildings, especially solar-powered civil buildings, can replace and save conventional energy and achieve sustainable development, which is a feasible way to solve the energy consumption of low-temperature buildings.