Thermal behavior of water-copper and water-stainless steel heat pipes operating in cycles

Heat pipes are a closed tube or chamber of different shapes whose inner surfaces are lined with a porous capillary wick, containing a saturated working fluid. It is a technology not restricted to aerospace applications, which is frequently used as thermal control devices of satellites and space vehicles. Some other sectors are finding interest on applying heat pipes to promote the thermal control of electronic equipment and heat exchangers performance augmentation. The use of heat pipes in such equipment allows the development of more compact and efficient heat exchangers compared to traditional designs, which increases the interest on applying them for industrial purposes. Heat pipes operating at mid-level temperatures have found several applications on both aerospace and industry segments. This work has the objective to present experimental results of heat pipes operation designed and manufactured in stainless steel and copper, using water as working fluid, operating on cycles at temperatures up to 200°C focusing on industrial applications. Test results showed reliable operation during the cycles, with fast start-ups and transients, achieving thermal conductances of up to 21.9 W/°C. Even though water-copper heat pipes present a better thermal performance when compared to the water-stainless steel heat pipes, there is a wide application not only for industry but also for aerospace.