The Experiment And Numerical Study On Heat Transfer And Stable Performance Of Steel-water Gravity Heat-pipe

As is well-known, heat-pipe which has another name as "super heat conductor" has high heat transfer coefficient. It works as heat exchanger equipment that rely on phase change and density difference of its working medium to finish the cycle process. Compare with the solid metal material with the same size, it has ten thousand times higher heat transfer efficiency even if cooper or silver. Since it was invented by1944, the heat-pipe technique has been applied from high-tech field to ordinary situation step by step these years. No matter applied by equipments in everyday life such as temperature controls of passenger car and cooling of electronic products, or to be the heat exchanger in heavy industry such as petrochemical and metallury industry, heat-pipe is more and more popular day by day.With advantage of price and cost, steel-water is quite suitable choice for large-scale applications to be heat exchanger in manufactory industries. Because of most mid-temperature situation in industry is pretty high for steel-water heat-pipe as working temperature, to be applied in these situations, its stability is the same important as efficiency. Then, to ensure it works stable and safety when we pursue the high heat transfer efficiency, research about its stability characteristic is very essentially.To explore the working characteristic of heat-pipe in working temperature among120℃～180℃, present work has built a steady state numerical model to calculate the distributions of vapor’s axis speed, wall temperature and pressure of steel-water gravity heat-pipe when it transport500W heat flow on normal temperature air cooled at first. Then set up an experimental platform to measure the influence of various factor for a heat-pipe working in that situation, which size is1m×Φ27mm×Φ21mm. Have study the working characteristic of steel-water gravity heat-pipe when it transport300W-600W between angle lean is0°～45°with six difference filling rate. By measuring the temperature of vapor and outside wall, present work not only investigated how efficiency of heat-pipe changing with angle lean, filling rate and heat flux, but also investigated the influence of those factor for its stability. Finally, present work simulated the dynamic working process of gravity heat-pipe, seized the procedure of carrying vibration phenomenon happens by build unsteady numerical model. Discussed the region of critical heat flux for carrying vibration phenomenon occur.