Design and principle of operation of the collector
Design:
The solar collector consists of vacuum tubes made of borosilicate glass. The vacuum between the pipes is an excellent insulator and prevents the loss of heat. In the process of triple magnetron metallization, an absorber (compound absorbing sun rays and transforming them into heat energy) is applied. The new special absorption layer ALN/AIN-SS/CU with the addition of copper is the next generation of absorption layers. The next layer, that is, the AL/N/AL layer, is characterized by higher efficiency (up to 12%) and excellent absorption properties of direct and diffused radiation. Additional layers of the absorber are designed to keep as much energy as possible inside the tubes and prevent heat loss through infrared radiation. The inside of the vacuum tube can heat up to 300ºC.
Inside the vacuum tubes is mounted the so-called "heat pipe." Aluminum radiators inside the vacuum tubes support the process of transfer of energy to the copper heat pipes. The lowering of pressure in the pipe, the sucking the air out, is done according to the principle of lowering the boiling point along with the pressure drop. The liquid/fluid inside the heat pipe exchanger boils already at 25ºC. Copper used in the production of the heat pipe is free of oxygen, which ensures the possibility of long and reliable operation.
The tank is made of SUS 304-stainless steel with thickness of 1,3 – 2,0 mm and is insulated with polyurethane foam with a thickness of at least 50mm. The whole set is factory tested at a pressure of 10 bar and can be connected directly to the water supply. Hot water flows from the tank pushed out by cold water (at the same pressure as in the water supply).
Principle of operation:
Under the influence of sunlight, the inside of the vacuum tubes heats up. The heat from the inside of the pipe is transferred to the "heat pipes" through the aluminum radiators. After a while, at 25 ºC the liquid in the "heat pipe" begins to evaporate. The vapor goes up to the exchanger head (condenser) where it releases heat through the collecting manifold and condenses. It flows down again into the "heat tube" to repeat the whole process. High efficiency of the collector results from the ability to absorb diffused radiation (for example, on cloudy days) and maximum reduction of heat loss. The collector works great also in winter. It obtains energy not only from direct sunlight but also from light reflected from snow.
The system does not require pumps, controllers, or equalizing tank for proper operation, which makes it very reliable. Water is only in the tank and flows out of it under pressure. The set can be placed on the ground and can supply water to the upper floors of the building.
In the event of a vacuum tube failure, the entire system will continue to operate, although the efficiency of the system will be lower. There are no fluids in the vacuum tubes, which means that the tube can be dismantled at any time without draining the system.
Advantages:
-The higher efficiency of the vacuum collector in comparison to a standard, flat collector.
- Simple design, low failure rate - service life of tubes over 15 years.
- Direct connection of the collector to the tank (no heat loss).
- Excellent insulation of the tank (daily loss of water temperature from 6 to 10 degrees C).
- No need to use pumps or controllers.
- Simple installation that does not require modification of the current system.
- Damage to the vacuum pipe from the "heat pipe" does not turn off the entire system, but only reduces the efficiency of the collector.
- Easy servicing and self installation possible.