Preparation And Properties Of MDF Cement-based Solar Absorption Material

Owing to the fossil fuel's non-renewability and serious environmental pollution after burning, so the development and utilization of renewable clean energy is of great significance. Solar energy is a kind of high efficient, clean and renewable energy that never fails, has a broad application prospect, but at the same time solar energy is decentralized, indirect and random that make it difficult to be utilized in a wider and broader range. Most of the human's buildings are cement concrete structures and spread all over the world, if we can use concrete to absorb and store solar energy that will make the application range of solar energy greatly expanded, and we will truly achieve the integration of solar energy utilization and buildings, but the solar absorption property and thermal property of the traditional cement concrete are both poor. In the preceding work of our project group, we selected graphite, carbon black, iron oxide black as the additive phases of heat absorption and conduction to do lots of inquiry experiments. The results show that although the additive of phases of heat absorption and conduction increases the solar absorption property and thermal property of cement-based composite material, at the same time it greatly reduces the material's mechanical property.In this study, graphite, carbon black, iron oxide black is single doped cement, this experiments were carried out under the conditions of the water requirement of normal consistency, the first test of these three materials on the mechanical properties of cement and absolutely dry bulk density changes, followed by the observation these three kinds material which added to cement the thermal performance. Finally, test the optical absorption coefficient of cement; utilize SEM analysis of the structure of graphite, carbon black, and black iron oxide on the morphology of cement hydration. Studies of these three substances improve the thermal performance of the cement, but the mechanical properties reduced at the same time.For example,16wt% of the single-doped graphite, the cement,s 28 d compressive strength was reduced 44.28% than the blank sample reduction The thermal conductivity raise from 0.9325W/(m·K) to 2.3292W/(m·K) thermal diffusion coefficient of 5.1261×10-7m-2·s-1 to 15.2139×10-7m-2·s-1, the heat capacity reduced from 173.52MJ/(m3·K) to 153.10MJ/(m3·K). The carbon black improved the light absorption coefficient mostly advantageous, by the iron oxide black, graphite minimum are followed But these three substances added can significantly increase the optical absorption coefficient of the material. By SEM analysis, the three materials was added to the cement, the cement stone structure will lose, and introducing the hollow crack.On the basis of single-doped experiments, choose the mass fraction the complex doped(orthogonal) experiments, testing the mechanical properties of the material, and absolutely dry bulk density and thermal performance, range analysis, the study of various substances on the performance of the material parameters and the impact of the law, identify the optimal ratio. complex doped(orthogonal) experiments Using SEM analysis of the morphology of cement hydration.Select no wind, sunny day, and the sunlight endothermic properties of single blending complex doped experiments. Recording the bottom of the plate and the plate surface of the sample changes over time and the highest temperature, while recording the ambient temperature. By contrast analysis of the maximum temperature, the graphite, carbon black, and iron oxide black single blending Admixed on cement endothermic temperature. The study shows that the thermal conductivity of a significant impact on the actual endothermic, orthogonal test sample No. 9, doped with 24wt% of graphite, carbon black is mixed with 16wt% iron and oxide black mixed 20wt%, the endothermic highest average temperature than the blank samples increased 8.23 ?The results of the actual solar endothermic experiment show that the actual endothermic effect of the cement admixed better than single-doped, graphite, carbon black, iron oxide black play their own material advantage, improved significantly with the collector effect. Therefore, in the mortar experiment, only select multiplexing(orthogonal)doped experiment. Standard fluidity was measured before the experiment and in the experiments under standard fluidity. The mechanical properties of the test materials must dry bulk density and thermal performance, through the quadrature analysis, studies of graphite, carbon black, and black iron oxide material performance parameters. The subsequent mortar the actual endothermic experiments sunlight, studies have shown that the maximum temperature than the the mortar blank sample temperature is 10.82?.