Papers by Keyword: Refractory Concrete

Abstract: The prospect of further use of refractory concrete based on barium-containing alumina cement was justified, with the help of a simplex-lattice method of the experiment planning, the granulometric composition of concrete was selected and its physical, mechanical and technical properties were determined, which exceed the properties of the used analogues.

Abstract: Implementation of high temperature solar reservoirs is associated with problems related to the physical properties of materials, especially with temperature resistance of the material at temperature changes, with high heat capacity, with high thermal conductivity and with material fire resistance. In the case of silicate materials, more specific materials with favourable physical properties are available, which can be used for the construction of high temperature containers. The basic prerequisite for designing such container is the knowledge of the physical properties of the heat storage core and the thermal insulation ability of container cladding layers.The paper deals with the problem of identification of material properties of silicates in the wide temperature range up to 800 °C, using the standard measurement methodology, improved by additional temperature recording at a defined distance from the thermal source during the dynamic thermal development of the linear thermal source, well-known as the hot wire method.

Abstract: High-temperature behaviour of refractory composites needs proper experimental and theoretical analysis, coming from classical thermodynamics. The dependence of usual thermal characteristics, as the thermal conductivity and thermal capacity, on temperature, cannot be neglected in any computational simulation, thus the experimental identification of their effective values is required. Whereas valid technical standards related to the hot-wire measurement technique enables us only certain approximate evaluation of thermal diffusivity, the very similar experimental configuration, supplied by the more advanced physical, mathematical and computational analysis, offers a possibility of reliable simultaneous identification of more characteristics. The crucial application is to the selection of appropriate silicate materials for the design of high-temperature storage of solar energy where both high thermal conductivity and thermal capacity are required. The first results refer to certain magnesite-based products as the good choice.

Abstract: The paper presents the validation of physical properties of refractory concrete with heavy filling, using the measurements under high temperature, assumed for the construction of a thermal storage. The whole system, consisting of the storage core and of the insulation container, is characterized by non-stationary thermal transfer, supplied from solar radiation into the core. The validation of behaviour of the system (including its sleeping state and the dynamics of charging and discharging) is needed for the optimization of its size parameters.