For calculating the thermal storage time for an annular tube with phase change material （PCM）, a novel method is proposed. The method is suitable for either low-temperature PCM or high-temperature PCM whose initial ...For calculating the thermal storage time for an annular tube with phase change material （PCM）, a novel method is proposed. The method is suitable for either low-temperature PCM or high-temperature PCM whose initial temperature is near the melting point. The deviation fit is smaller than 8% when the time is below 2x104 s. Comparison between the predictions and the reported experimental data of thermal storage time at same conditions is investigated and good agreements have been got. Based on this method, the performance of the thermal storage unit and the role of natural convection are also investigated. Results show a linear relation between the maximum amount of stored heat and thermal storage time, and their ratio increases with the height of the thermal storage unit. As the thickness of the cavity increases, natural convection plays an increasingly important role in promoting the melting behavior of paraffin. When the thickness of the cavity is small, natural convection restrains the melting behavior of paraffin.展开更多
In order to fundamentally solve the acidification problem of high sulfur-containing bauxite during storage, by simulating the environment of minerals storage in laboratory, the acidification mechanism and influencing ...In order to fundamentally solve the acidification problem of high sulfur-containing bauxite during storage, by simulating the environment of minerals storage in laboratory, the acidification mechanism and influencing factors of high sulfur-containing bauxite were studied and confirmed using the single variable method to control the atmosphere, water and other variables. The results show that the acidification is mostly caused by the oxidation of sulfur-containing bauxite, which is mainly the natural oxidation of Pyrite(Fe S2), then the alkaline minerals dissolute in the presence of water, leading to the acidification phenomenon, which is influenced by moisture and air flow. Finally, more acid-producing substances are formed, resulting in the acidification of high sulfur-containing bauxite. The acidification of high sulfur-containing bauxite results from the combined effect of the oxygen in the air and water, which can be significantly alleviated by controlling the diffusion of the oxygen in air.展开更多
基金Projects(51666006,51406071,51174105,51366005)supported by the National Natural Science Foundation of ChinaProject(2014CB460605)supported by the National Basic Research Program of China
文摘For calculating the thermal storage time for an annular tube with phase change material （PCM）, a novel method is proposed. The method is suitable for either low-temperature PCM or high-temperature PCM whose initial temperature is near the melting point. The deviation fit is smaller than 8% when the time is below 2x104 s. Comparison between the predictions and the reported experimental data of thermal storage time at same conditions is investigated and good agreements have been got. Based on this method, the performance of the thermal storage unit and the role of natural convection are also investigated. Results show a linear relation between the maximum amount of stored heat and thermal storage time, and their ratio increases with the height of the thermal storage unit. As the thickness of the cavity increases, natural convection plays an increasingly important role in promoting the melting behavior of paraffin. When the thickness of the cavity is small, natural convection restrains the melting behavior of paraffin.
基金Project(2013AA064102)supported by the National High Technology Research and Development Program of China
文摘In order to fundamentally solve the acidification problem of high sulfur-containing bauxite during storage, by simulating the environment of minerals storage in laboratory, the acidification mechanism and influencing factors of high sulfur-containing bauxite were studied and confirmed using the single variable method to control the atmosphere, water and other variables. The results show that the acidification is mostly caused by the oxidation of sulfur-containing bauxite, which is mainly the natural oxidation of Pyrite(Fe S2), then the alkaline minerals dissolute in the presence of water, leading to the acidification phenomenon, which is influenced by moisture and air flow. Finally, more acid-producing substances are formed, resulting in the acidification of high sulfur-containing bauxite. The acidification of high sulfur-containing bauxite results from the combined effect of the oxygen in the air and water, which can be significantly alleviated by controlling the diffusion of the oxygen in air.
