Abstract

The processes of heating and melting of materials in a concentrated high-density solar flux at the Large Solar Furnace are studied. The possibilities of calculating the rate of heating and cooling of molten materials are shown using the example of pyroxene rocks exposed to concentrated solar radiation. The influence of the main technological factors (the heating rate of the substance to the melting point and above, as well as the cooling rate) on the quality of the melt is studied. The equation of heating due to the absorption of solar radiation is constructed taking into account convective heat transfer and heat loss due to thermal radiation. The melt cooling process is described by the Newton–Richmann law taking into account thermal conductivity, convection, and radiation. Three different types of cooling of the melt at different rates were implemented. It is shown that by choosing the melt cooling method, various cooling rates can be achieved: 10², 10³, and 10⁴ K/s. The dependences of the grain size of the material on the cooling rate were obtained. The dependences of the microstructure of the material obtained from the cooled melt on the cooling rate of the melt were analyzed. It is shown that, within the context of the model, taking into account assumptions and initial conditions, it is possible to describe the processes of heating and cooling of pyroxene rocks under the influence of concentrated solar radiation of high density. It was revealed that the melt cooling rate, which has a strong influence on the dispersion of the obtained material, is determined by the method of melt cooling. To obtain a hardened material with nanosized particles, it is necessary to cool the melt at a rate above 10⁶ deg/s.

中文翻译：

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太阳能炉中材料加热和冷却过程的建模

摘要

研究了大型太阳炉在高密度聚光太阳能通量中材料的加热和熔化过程。以暴露在集中太阳辐射下的辉石岩石为例，显示了计算熔融材料的加热和冷却速率的可能性。研究了主要工艺因素（物质到熔点及以上的加热速率以及冷却速率）对熔体质量的影响。考虑到对流传热和热辐射造成的热损失，构造了由于吸收太阳辐射而产生的加热方程。牛顿-里希曼定律描述了熔体冷却过程，其中考虑了热导率，对流和辐射。实施了三种不同类型的熔体以不同的速率冷却。结果表明，通过选择熔融冷却方法，可以实现各种冷却速率：10²，10 ³，和10 ⁴ K /秒。获得了材料的晶粒尺寸对冷却速率的依赖性。分析了从冷却的熔体获得的材料的微观结构对熔体的冷却速率的依赖性。结果表明，在模型的上下文中，考虑到假设和初始条件，可以描述在高密度集中太阳辐射的影响下辉石岩石的加热和冷却过程。揭示了通过熔体冷却的方法来确定对所得材料的分散性有很大影响的熔体冷却速率。为了获得具有纳米尺寸颗粒的硬化材料，必须以高于10 ⁶的速率冷却熔体 度/秒