All-glass features
A vacuum tube introduced
(1) vacuum structure: all-glass vacuum tube solar collector is the core component is the engine of the entire solar system, its performance determines the merits of the whole system was thermal performance and longevity.
Schematic diagram of the all-glass vacuum tube
All-glass vacuum tube one end of the opening, the inner tube and outer tube of the nozzle to melt sealing ring; the other side were closed into hemispherical head, inside the glass tube with a spring support bracket on the outside glass to buffer thermal expansion shrinkage caused by stress. Including glass and laminated between the outer glass tube into a high vacuum pumping. The end of the outer tube to protect the general bonding a metal cap to protect the vacuum after the closure of the exhaust nozzle. The appearance of glass topcoat selective absorbing coating. Spring bracket is equipped with a cool down agent, it is used in evapotranspiration after the vacuum tube to absorb the gas generated at run time, to keep the tube from the vacuum effect.
(2) Tube Material requirements: 3.3 borosilicate glass vacuum tube used (iron oxide content of below 5%; thermal stability; low coefficient of thermal expansion, as 3.3 × 10-6 / ?; thermal shock resistance, heat resistance temperature is greater than 200 ?; have high mechanical strength; good resistance to chemical corrosion; has good optical properties, transmittance ≥ 0.89).
(3) vacuum tube technology requirements:
? material is borosilicate glass, 3.3;
? air drying performance parameters y ≥ 175m2 ? / kW (when the solar irradiance G ≥ 800W / m2, the ambient temperature t at between 8 ~ 30 ?)
? nausea drying temperature increased to 35 ? required amount of solar radiation exposure ≤ 3.8MJ / m2 (when the solar irradiance G ≥ 800W / m2, the ambient temperature t at between 8 ? ~ 30 ?)
? average heat loss coefficient ≤ 0.9W / m2 · ?
? vacuum ≤ 5 × 10-2Pa;
? should be able to withstand the thermal shock of cold water below 25 ? and 90 ? above the impact of hot water alternately repeated 3 times without damage;
? pressure should be able to withstand the impact of the pressure of 0.6MPa;
? hail requirements should be not more than 25mm in the radial size of the hail damage is not under attack.
(4) vacuum tube specifications.
Second, the vacuum
Solar water heaters is the use of the greenhouse theory, the solar energy into heat energy, in order to achieve the purpose of heating the entire package of water, usually by the solar collectors, storage tanks, brackets, a combination of controllers and other accessories, if necessary, to increase aid heat source.
(1) how it works:
Solar hot water heater is a light converter, different from the traditional use of nature, such as drying, lighting. Vacuum tube solar water heater is the core of his elongated structure as a thermos bottle lamps, a vacuum between the inner and outer layers. On the surface, including glass coated with a special process using spectral selective absorbing coating, to maximize absorption of solar radiation. By sunlight, photon hits the coating, solar energy into heat energy, water absorbs heat from the outside coating, water temperature, density decreases, the upward movement of hot water, while the proportion of cold water down. Hot water is always located in the upper part of the tank. Also hot water heating solar water heater in case the temperature has little to do with the outside world, depending on the light. When you open a kitchen or bathroom faucet any time, the hot water heater will depend on the natural fall out, the greater the gap, the higher the water pressure.
(2) solar water heater structure
(3) solar hot water system plans
Third, all-glass vacuum tube solar collector
(1) all-glass vacuum tube solar collector operating principle
(2) all-glass vacuum tube collectors, the basic structure
Number of branch tubes are arranged according to certain rules of the union of vacuum tube arrays with the tube (or Header), tail bracket and reflectors and other components together to form a vacuum tube collectors.
All-glass vacuum tube collectors are generally associated box round and square, the use of stainless steel production, collector piping joints welded at both ends in the United box. Side or both sides of the joint box according to the design of the vacuum space hole, directly into the open end of tube joint box, tube and between the United box sealed by silicon rubber seals.
In order to improve the performance of vacuum tube collectors, some of the manufacturers of products in the back of the addition of vacuum tube array reflector, mostly flat diffuser, generally aluminum or painted flat white paint is made. Because the reflector long-term exposure to air, easy to accumulate dust and dirt, require frequent cleaning, or reflections will be affected, and the collector reflector increases drag and affect the stability of collector installed, so the sand relatively large areas should not be installed with a reflector plate collector.
All-glass vacuum tube solar collector structure diagram
According to the different vacuum tube installation, all-glass vacuum tube collectors can be divided into vertical alignment (north-south) and horizontally (east-west) two order forms, of which there are arranged horizontally level of single-row and two kinds of double standards the form.
(A) vertical arrangement of all-glass vacuum tube solar collector
(A) levels arranged in all-glass vacuum tube collector (double)
All-glass vacuum tube solar collector arrangement diagram
(3) application
As the vacuum tube collector has a simple structure, excellent performance, advanced production technology and reliable, especially for large-scale mass production characteristics, so since its inception, in just a few years it has been considerable development. However, due to pipe the water to go in the running if a damaged, the entire system will stop working; and a larger heat capacity of the vacuum tube, vacuum tube solar water should be heated to the output of hot water, and the evening, vacuum tube the hot water will not be fully utilized, resulting in a certain amount of heat loss. Vacuum tube collector can not be used in pressure systems, generally open only for centralized s. Products can not be used for the balcony wall.