A solar collector is a device that is designed to collect and convert thermal solar energy, it is carried by visible light and infrared radiation. The principle of operation of such a device differs markedly from the principles of operation of solar panels. The solar collector does not produce electrical energy, it only heats the heat carriers. In fact, this device can be called a simple source of thermal energy. At the moment, there are two main types of such a device as a solar collector: vacuum and flat. The main characteristic of any such device is the absorption coefficient. For collectors, it is 95-98 percent, which is a lot.
Vacuum solar collector can collect solar radiation in virtually any weather. Its work and efficiency (efficiency) do not depend on the external temperature. The main advantage of such a device is the possibility of its full performance even at low temperatures. This is very important for Nordic countries and regions. Also, a vacuum solar collector can be seasonal and out-of-season in design and the way the water is heated.
In the seasonal system, the storage tank and vacuum glass tubes are mounted under one frame. The tubes enter directly into the storage tank thanks to the sealing rubber ring. The water in the vacuum tubes is heated. Due to its natural circulation, hot layers begin to rise into the tank. Such a solar collector is connected to the water supply through shut-off valves, which maintain the water level in the storage tank. Hot water from the storage tank can be used for any household needs. The advantage of such a system is its convenience and reliability, so it is quite easy to make and operate a home-made solar collector of this type at home. However, such devices can be used in temperate climates, somewhere from mid-spring to early autumn, before the onset of night frosts.
All-weather or separating collectors are a little more difficult due to their versatility. The principle of their operation resembles the operation of central heating installations. Such a closed system, unlike the seasonal one, works only under the pressure of the water supply. In such a solar collector, special vacuum tubes are used that can operate at very low temperatures (up to -40 ° C) and under water pressure.
The collector itself and the storage tank are located separately and are interconnected by a pipeline. The collector is usually mounted on the roof of the building, and the tank isthe drive is inside. Such a system is sometimes called a split system. The operation of the entire system of such a device as a vacuum all-weather solar collector is automated by special controllers. The coolant is forced to circulate in the system. For this, specialized circulation pumps are used.
