Solar Collector Part Heat Pipe Evacuated Tube

Solar Collector Part Heat Pipe Evacuated Tube

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.