Can heat pipes be used for cooling?
Today, heat pipes are used in a variety of cooling applications from space to medical devices and power electronics cooling to aircraft and more!
What is a heat pipe how does a heat pipe work?
A heat pipe is a two-phase heat transfer device with a very high effective thermal conductivity. It is a vacuum-tight device consisting of an envelope, a working fluid, and a wick structure. As shown in the video below, the heat input vaporizes the liquid working fluid inside the wick in the evaporator section.
Why heat pipes are used in heat exchanger?
Inside a heat pipe, boiling and condensing heat transfer mechanisms transfer heat. For these mechanisms, heat transfer can proceed at extremely high rates as compared to conduction and/or convection. Wall grooves or wicks are used inside the heat pipes to improve wall wetting and heat transfer.
Where are heat pipes used?
Heat Pipes for Dehumidification and Heat Recovery In their simplest form, a heat pipe is a sealed tube containing a phase-change fluid. The heat pipes for HVAC applications are usually made of copper tubes, aluminum fins.. Different working fluids are used to suit various temperature ranges.
How effective are heat pipes?
Due to the very high heat transfer coefficients for boiling and condensation, heat pipes are highly effective thermal conductors. The effective thermal conductivity varies with heat pipe length, and can approach 100 kW/(m⋅K) for long heat pipes, in comparison with approximately 0.4 kW/(m⋅K) for copper.
Do heat pipes have liquid?
The most common heat pipe working fluid is water for an operating temperature range from 1°C to 325°C. Low temperature heat pipes use fluids such as ammonia and nitrogen. High temperature heat pipes utilize cesium, potassium, NaK and sodium (873–1,473°K).
What is heat pipe dry out?
When the quantity of heat pipes is not enough to bring the heat away, the liquid in the wick to the boil and evaporate, which causes there is no liquid to absorb the heat and the heat pipes goes into a dry-out condition.
Are heat pipes expensive?
Are heat pipes expensive? Compared with traditional (and less effective) heat transfer methods such as aluminum extrusions and cast heat sinks, heat pipes can have a higher initial cost. That is why heat pipes are not recommended for applications where cooling can be performed by simple conductive heat sinks.
Does more heat pipes mean better cooling?
As a general rule, more heatpipes means better cooling. Additional vapor chambers may aid in heat diffusion for some units, but are not as common as traditional heatpipes. Fan positioning and number of fans. More fans means better cooling, but potentially more noise.
How are heat pipes used to cool power electronics?
By incorporating heat pipes onto the surface of an air cooled heat sink, high concentration of heat from power electronics can be spread out over a larger area are very quickly. This cooling technology is ideal for SiC and Power Amplifier applications. Heat Pipe Assembly
What kind of heat transfer device is a heat pipe?
Heat pipe. A heat pipe is a heat-transfer device that combines the principles of both thermal conductivity and phase transition to effectively transfer heat between two solid interfaces.
What kind of metal is used in heat pipes?
Aavid has constructed heat pipes from aluminum, copper, titanium, monel, stainless steel, inconel and tungsten. The most common for electronics cooling applications is copper.
Which is the best application for heat pipes?
Currently,one of the highest volume applications for heat pipes is cooling the Pentiumprocessors in notebook computers. Due to the limited space and power availablein notebook computers, heat pipes are ideally suited for cooling the high powerchips.