Characteristics:
A perfect combination of the vacuum tube and the heat pipe.
1) Higher heat efficiency:advanced heat transferring style of the heat
pipe,excellent selective absorb coating and perfect combination with high
vacuum heat preservation
2)Wide applicable range:as the heat pipe has the less
heat feature,it can be started quickly even under cloudy day and collect heat
effectively.It can work normally even below -30 degree.As no water in the
tube,it can effectively prevent low heat efficiecy due to frost cracking or
scaling.
3) Each tube can work independently,and the whole system can still work even if
one tube is damaged.The service life of the heat pipe can be longer than 15
years.
4) The unique connection between the heat pipe and the vacuum tube can ensure
both sealing and easy to replace the damaged glass vacuum tube.
Structure and Principle of Heat Pipe:
The heat pipe is hollow with the space inside evacuated,
much the same as the solar tube. In this case insulation is not the goal, but
rather to alter the state of the liquid inside. Inside the heat pipe is a small
quantity of purified water and some special additives. At sea level water boils
at 100oC (212oF), but if you climb to the top of a mountain the boiling
temperature will be less that 100oC (212oF). This is due to the difference in
air pressure.
Based on this principle of water boiling at a lower temperature with decreased
air pressure, by evacuating the heat pipe, we can achieve the same result. The
heat pipes used in AP solar collectors have a boiling point of only 30oC
(86oF). So when the heat pipe is heated above 30oC (86oF) the water vaporizes.
This va pour rapidly rises to the top of the heat pipe transferring heat. As
the heat is lost at the condenser (top), the va pour condenses to form a liquid
(water) and returns to the bottom of the heat pipe to once again repeat the
process.
At room temperature the water forms a small ball, much like mercury does when
poured out on a flat surface at room temperature. When the heat pipe is shaken,
the ball of water can be heard rattling inside. Although it is just water, it
sounds like a piece of metal rattling inside.
This explanation makes heat pipes sound very simple. A hollow copper pipe with
a little bit of water inside, and the air sucked out! Correct, but in order to
achieve this result more than 20 manufacturing procedures are required and with
strict quality control.