Flat heat pipe panels (HPPs) have attached substantial attention due to their advantages such as geometry adaptation, ability for localized heat dissipation and production of entirely flat isothermal surface. Flat HPPs can be applied as bathroom floor heaters, ceiling cooling elements, as a component of sales cabinets for chilled and frozen products and as cooling systems for electronic devices and space vehicles.

Pulsating HPPs are considered as an interesting alternative to the conventional cylindrical heat pipes. Recently flat HPPs are becoming very efficient as thermal control devices for water sorption coolers and air-conditioning systems owing to the low pressure inside the envelope, when porous sublimator heat exchangers are used instead of evaporators. HPPs for water sorption technologies are really exciting, since water is the most welcomed fluid for modern air-conditioning.

Pulsating HPPs are perspective semi-passive, high-power, high flux heat transport device. They are unique due to capability of generating driving pressures in excess of many mechanically pumped loops. Capillary forces do not limit the HPP and it is capable to transfer high heat loads over long distances and against significant resistance (i.e. gravity, small tube diameters etc.).

Low pressure working fluids like water, alcohol and some hydrocarbons (for instance, propane, butane) are suitable for pulsating HPPs.

HPP with a thin sorbent bed covering placed on the fin surface are convenient for the thermal control systems of refrigerators and heat pumps. Thermal resistance of the developed device is 0.05 K/W, evaporator heat transfer coefficient is 8500 W/m²/K, condenser heat transfer coefficient is 2500 W/m²/K.Pulsating HPPs with a thin sorbent bed covering placed on the fin surface may be used for the thermal control systems of refrigerators and heat pumps. A thin coating of the adsorbent on a heat exchange surface of HPP ensures high heat transfer rates. Application of coverings and water, methanol, or propane/butane as refrigerants has been recently proposed for using in sorption machines for cooling.

Published in
PULSATING HEAT PIPE PANELS
A.A. Antukh, M.I. Rabetsky, V.E. Romanenkov, L.L. Vasiliev
Heat Pipe Theory and Applications, Proceedings of the 13th International Heat Pipe Conference September 21-25, 2004 Shanghai, China