GLASS HEAT PIPE EVACUATED TUBE

Sistem Tubular

What is Glass Heat Pipe Evacuated Tube?

Glass heat pipe evacuated tube also consists of a two layers of glass with a vacuum in between the layers like conventional solar vacuum tubes. On the other hand, its difference from conventional vacuum tubes is that the open end of the tube is closed using a special geometry like a dome shape to increase resistant to axial loads in pressurized reservoir systems.

This enclosed area, which is inside the inner tube, is vacuumed and a heat transfer fluid is injected into it.

Advantages

No Calcification Problem

Contrary to conventional vacuum tubes, there is no water circulation inside the tube, so calcification problem due to water is prevented.

No Rrisk of Breakage

Due to no water circulation, there is no risk of freezing or breaking the tube in winter.

How It Works?

The special selective coating on the outer surface of the inner tube changes solar radiation into the heat radiation and then the absorbed solar radiation is transferred to a heat transfer fluid within the tube.
This liquid quickly heats up, changes its form to gas and rises to the top. It reaches the dome shaped condenser in the usage water reservoir.

Since the outer surface of the condenser is in contact with the relatively cold usage water in the reservoir, the heat transfer fluid in the form of gas condenses on the inner surface of the condenser.
The condensing chemical returns back in droplets to the sun-exposed base of the tube.
As long as the system is heated by the sun, the circulation continues.

Features

Length	1930 mm
Outer Tube Diameter	47 mm
Inner Tube Diameter	37 mm
Thermal Expansion	3.3x10-6 °C
Material	Borosilicate Glass 3.3
Surface Coating Material	AL-CU-SS Selective
Light Absorbsion Rate	%96
Emission Rate	4-5 %
Vacuum	P<0.004 Pa
Empty Tube Temperature	>200 °C
Heat Loss Coefficient	<0.8 W/m2 .K
Reflection Ratio	%7 (100 °C )