| Social and economic development have made energy crisis a tough problem,especially under the contradiction between the increasing demanding and shortage ofsaving. Among various energy saving technology, heat storage is environmental friendlyand with high efficiency of energy use. Specifically, latent heat thermal storage hasbecome a hot topic due to its high storage density and low temperature range during heatstorage process. Currently, phase change material (PCM) and heat reservoir structure aretwo main research areas within the heat storage technology.In this paper, using paraffin wax as PCM, the theory of latent heat thermal storagewas firstly studied and the physical and mathematic model were built based on the thoery.Secondly, by numerical simulation, temperature distribution during the heat storage andrelease process in the multitube model was analyzed. Simulation results showed thatcompared with concentric tube, multitube model not only shortens the time needed by heatstorage and release, but also uniforms the temperature distribution. Finally, experimentaltable of telescopic phase change heat reservior was built. By controlling the flow ofthermal fluid, tests with different thermal fluid were done about the heat storage andrelease. Temperature date from different thermocouples within the heat reservoir werecollected and analyzed in order to see the influence of thermal fluid on the performance ofthe heat reservoir. After comparing simulation results with experimental statistics, it isfound that the temperature field changes almost the same on both radial direction and axialdirection. However, as there is certain simplification during modeling (also there is heatloss during experiments), it is reasonable that errors are found between simulation resultsand experimental statistics.By numerical simulation and experimental study on telescoping heat reservoir, thispaper provides valuable information for the design and optimization of phase change heatreservoirs in the future. |
PDF Full Text Request