Maximum use in everyday life alternative energy sources is a key task on which constantly working engineering minds. And in this regard they have achieved significant results, regularly introducing the all new device that allows to organize a comfortable existence, provided a significant reduction in the consumption of traditional electricity. One such interesting development is the vacuum solar collector. Familiarization with the structure and principle of operation of the equipment will help to better know his dignity and determined purpose in life.
Design of solar collectors are very different. It can be flat or vacuum heaters, as well as the equipment as a coolant instead of water are involved the air. In detail, we will focus on the vacuum modifications, as this is the type of solar collector has high efficiency and many other undeniable advantages.
The purpose of the vacuum manifold, which is based on the conversion of solar radiation into heat energy, has a wide variable range. The greatest demand is observed, if necessary, heat water in large volumes. A step below the aim is to organize the heating of the room due to the installation of solar equipment in the form of vacuum manifold. His power to heat the water in the swimming pool or to provide a warm floor during the cold season. An important aspect of operating a solar collector is its environmental friendliness and safety.
The main difference between vacuum heaters from other constructions of solar collectors is the presence of a base panel fixed glass pipes. As the material is borosilicate glass, characterized by high strength and preserving the optical properties over a long period. For coating uses a special substance that provides the attraction of the sun. Inside of the larger tube is smaller in diameter product, the space between them is filled with vacuum.
At the bottom of the tube contains a special fluid which under the action of the sun’s energy is converted into steam and rises up, thereby ensuring uniform heating of the water in the vacuum manifold. The device of the equipment represented in the diagram below:
The design of the vacuum compartment provides a solar collector according to the thermos flask principle. Basic elements of equipment mainly include the following parts:
- heat accumulator, in his role often acts as the water tank;
- the contour for the heat exchanger;
- temperature sensors;
Let us examine the functions of each part in detail. The receiver is made of copper, insulated with polyurethane method. Additional protection is represented by a coating of anodized aluminum. Through the supply of thermal energy. The detection of a fault in the receiver, the replacement procedure is trouble-free, it does not require draining of the fluid from the heat exchanger.
At the end of the vacuum tubes of the solar collector and on the reverse side of the heating device installed temperature sensors. On the basis of their indicators is the circulation pump.
The working principle of solar heater is as follows:
- The role of the heat transfer medium antifreeze, which passing through the upper zone of equipment that absorbs thermal energy issued by a special ferrules copper alloy.
- As a result of application of the mechanism of the coil in the storage tank the vacuum solar collector is heating the fluid.
- Heat transfer in a closed cycle is maintained as long as the degree of the liquid is not be above the temperature of the water in the storage tank.
Factors determining the period of operation of such a system are temperature readings of the atmosphere and the duration of daylight.
Vacuum drives that use the energy of sunlight, there are direct and indirect heat flow. The first version of a vacuum manifold is characterized by the use of water as coolant, so it belongs to the seasonal equipment operating from solar energy. In the second case, possible year-round operation of the device.
Compliance with recommendations for the installation of the vacuum manifold – the key to high performance of solar heater. The right location provides heating of the fluid in the cold season 50-60% for the summer period, the figure is 100%.
For these purposes, are not suitable galvanized steel or plastic pipelines. Stainless steel or copper is the optimal material. So, what should pay attention:
- When mounting on the roof of the buildings, the angle of inclination of the vacuum manifold to the horizon equals the latitude of the area.
- Accommodation in open spaces with solar heater should be in close proximity to buildings which consume heat.
- Shading factors should be deleted.
- Maximum efficiency in the operation of solar collectors reached when the angle of incidence of the sun’s rays is 90on.
However, to achieve compliance with this condition is difficult because of the constant movement of the vacuum heater relative to the sun’s rays. The perfect solution – install cell manifold that supports the desired angle of inclination by rotation of the sun. But the cost of such equipment is prohibitive, so much more profitable to exploit more simple in technical terms, vacuum collectors.
When selecting the angle of inclination oriented to the main purpose of the solar heater, and you choose the direction to the southern side. The maximum deviation must not exceed 30on. In the Northern regions of the vacuum manifold is carried almost vertically. Such devices are effective in the winter season, as they use the light reflected from snow cover. Sometimes solar collectors fixed on the walls of the housing, receiving the following benefits:
- easy maintenance;
- less accumulation of dust, respectively, is facilitated by care;
- the risk of hail damage is minimized;
- low mount vacuum manifold relative to the tank with the heated liquid increases the rate of convection, the need for an active system, there is no.
- wall-mounted solar collector type vacuum reduces the heat loss of the room, reducing the need for additional energy for heating.
The smooth operation of solar vacuum equipment provide isolated devices. This allows you to operate the whole system at temperatures down to -40onC. In this case, the device with the storage tank have separately, connecting with the main part of the vacuum manifold with the help of sheet metal products.
Automated operation of the indirect devices of the vacuum manifold to provide the controllers, the pump provides continuous circulation of fluid in the system. Among the advantages of the solar collectors of the vacuum type are the following positions:
- high efficiency in cloudy weather or freezing temperatures;
- the mounting structure of vacuum equipment does not require special skills;
- stability of the solar heater to negative environmental influences;
- long service life.
The only aggravating point may become the high cost of the solar heater, but due to the long lifespan, the money invested will be repaid in the next period, providing further significant savings on energy costs.