Theoretical And Experimental Research On Liquid Metal High Temperature Heat Pipe

Based on the new trend of the R&D of heat pipe in the world and the current condition of our country, the theoretical and experimental research of liquid metal high temperature heat pipe (HTHP) was carried out in this dissertation. The sodium-potassium alloy (NaK) HTHP was invented (China patent 96117175.8) by present author and co-workers. The results and conclusions of theoretical and experimental research on this new kind of HTHP will offer necessary reference to the design, production and application of liquid metal HTHP in industry, especially in the energy engineering.At the first, the properties of various of liquid metal working fluids were studied in detail. No matter which were the common working fluids, or the promising ones were discussed and analyzed. Then the new idea of using NaK as the working fluid of HTHP was consequentially suggested by present author and co-workers. As a result, one gap in the field of heat pipe is filled.With the review of the classic theory of HTHP, the theory system about liquid metal HTHP from frozen state to steady state was summarized, including transient two-dimensional rarefied vapor (free-molecular) self-diffusion model, concept of transition temperature range from free-molecular to continuum vapor flow, flat-front model for analytical solution, transient two-dimensional compressible laminar vapor flow model and steady two-dimensional incompressible laminar vapor flow model. Then the theory of gravity HTHP was analyzed firstly by present author. Moreover, the mechanism of phase change heat transfer of liquid metal for NaK alloy was discussed, as well as the limitations of heat transfer of liquid metal HTHP with NaK alloy were analyzed.Secondly, potassium and sodium-potassium alloy liquid metal HTHPs were experimentally examined to check or clarify their characteristic of start-up, isotherm, steady operation and heat transfer capacity. Some test results were compared with the numerical calculations. In addition, the experimental conclusions may provided reliable reference to the design of application.The equipment, technology and technique about large scale industrial production...