The solar collector is such 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 carries out heating of the coolants. 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.
A vacuum solar collector can collect solar radiation in virtually any weather. Its work and efficiency (coefficient of performance) are independent of external temperature. The main advantage of such a device is the possibility of its full functionality even at low temperatures. This is very important for northern countries and regions. Also, the vacuum solar collector can be seasonal and non-seasonal according to the design and the way in which the water is heated.
In the seasonal system, the storage tank and vacuum glass tubes are mounted under one frame. The tubes directly enter the storage tank thanks to the rubber sealing 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 domestic needs. The advantage of such a system is its convenience and reliability, so it is quite simple to make and operate a home-made solar collector of this type at home. However, you can use such devices in a temperate climate, somewhere from the middle of spring to the beginning of autumn, until night frost.
All-season or dividing collectors are a bit more complicated due to their versatility. The principle of their operation resembles the operation of central heating systems. Such a closed system, unlike the seasonal one, works only under the pressure of the water supply. Such a solar collector uses special vacuum tubes that can operate at very low temperatures (up to –40 ° C) and under pressure from the water supply.
The collector 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 storage tank 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 circulates in the system forcibly. For this, specialized circulation pumps are used .