| Summary: | 碩士 === 國立臺灣大學 === 土木工程學研究所 === 101 === In the condition of greenhouse effect and outdoor temperature raised, the heat which enters into the indoor increases. The air conditioning energy consumption will increase, causing the energy shortage. In the study, the phase change materials have the latent heat, which can absorb large amounts of heat. The research is about investigating the characteristics of the phase change wallboard in Taipei weather conditions and the behavior of the indoor ambient temperature performance.
There are three parts of experimental and simulation analysis. The first part is the heat conduction properties of the phase change concrete, including the thermal diffusivity, heat capacity and the unit weight in the formula for calculating thermal conductivity. When the amount of phase change materials increased, the concrete is lighter. When the amount of phase change materials increased, the heat capacity is higher. There is a peak on the standard phase transition temperature. Due to the phase change materials resist heat (cold) source from advancing, which concrete adds the phase change materials, the thermal diffusivity will decrease. The final, thermal conductivity in the non-phase change temperature section is lower, when the amount of phase change materials increased. In the phase change temperature section, the thermal conductivity coefficient curves overlap. Addition of 10%, 20% and 30% thermal conductivity peaks are 1.73 W/m∙K, 1.61 W/m∙K and 1.67 W/m∙K, which are lower than the thermal conductivity (2.0 W/m∙K) of the concrete without adding the phase change materials.
The second part is hot box tests. Our group uses the hot box instrument in NTU civil engineering materials laboratory, sets Taipei 2012 summer temperatures, winter temperatures and design cycle temperature as schedule of testing. In summer test, when the amount of phase change materials increased, the indoor high temperature is lower and high-temperature peak time of occurrence delays. In winter test, found that addition of the phase change materials causes the rising of low temperature. The cycle test of 20℃~40℃, 12 hours a cycle, adding phase change materials, the temperature can be controlled in a small temperature range. The the temperature differences of addition of 0%, 10%, 20%, 30% are 9.6℃, 7.4℃, 5.7℃, 5.1℃, but the delay time are shorter than the summer test results.
The third part is ABAQUS simulation analysis for the cycle test. Comparing the results for the phase transition temperature of the material added control behavior, software simulations have accurate results. Temperature peak delay phenomenon in the software simulation can also be seen.
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