Re: Heat Pipe Tube 구조와 원리

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Brief Introduction:

Start fast,Transfer heat with negligible loss,High efficiency in thermal transfer,High freeze resistance,Long service life.Heat pipe is one of the core technologies of Hitek,which is produced by self-developed automatic filling machines,with vacuum grade up to 2 × 10-2Pa inside,it will output energy when the temperature of medium liquid inside heat pipe reaches20℃.

Technical data：

Type	Ф14×1680	Ф14×1710	Ф24×1800
Segment condensation temperature (℃) (Hot water temperature70℃）	≥ 62
Start-up (25℃) (s)	≤ 60	≤ 60	≤ 60
Average temperature performance (℃)	≤ 3.5	≤ 3.5	≤ 4
Heat transfer (W)	≥ 120

Heat pipes might seem like a new concept, but you are probably using them everyday and don’t even know it. Laptop computers often using small heat pipes to conduct heat away from the CPU, and air-conditioning system commonly use heat pipes for heat conduction.

The principle behind heat pipe’s operation is actually very simple.

Structure and Principle

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 Hitek Solar collectors have a boiling point of only 25oC (77oF). So when the heat pipe is heated above 25oC (77oF) the water vaporizes. This vapor rapidly rises to the top of the heat pipe transferring heat. As the heat is lost at the condenser (top), the vapor 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.

Even though the heat pipe is a vacuum and the boiling point has been reduced to only 25-oC (77oF), the freezing point is still the same as water at sea level, 0oC (32oF). Because the heat pipe is located within the evacuated glass tube, brief overnight temperatures as low as -25oC (-13oF) will not cause the heat pipe to freeze. Plain water heat pipes will be damaged by repeated freezing. The water used in Hitek heat pipes still freezes in cold conditions, but it freezes in a controlled way that does not cause swelling of the copper pipe.