Research On Preparation And Modification Of Bio-PCM In Building

In order to satisfy the fundamental needs of the indoor comfort level in buildings, the power consumption from air-conditioning is becoming more and more enormous. However, the partial fatty acid esters of biomass phase change material(Bio-PCM) from illegal cooking oil has the following advantages:environmental protection, the suitable phase change temperature, the higher latent heat, and applied in building envelopes by a modified technique. So, to some extent, Bio-PCM can be studied to regulate indoor temperature and reduce power consumption. Based on the actual engineering application oriented, this paper can pave the way for the next stage by the previous experimental study and numerical simulation. The main research work includes the following aspects:In the preparation and performance testing of Bio-PCM in building, choose the target product between 22 ℃ and 27 ℃. Firstly, by transesterification and hydrogenation reaction, get the Bio-PCM. Then, use the T-History method to measure the phase change temperature and latent heat from Bio-PCM. Finally,choose out of the type and proportion of Bio-PCM that can satisfy the indoor comfort.In the modified performance analysis of Bio-PCM in building, use the expanded graphite to adsorb the Bio-PCM, improve thermal conductivity and prevent Bio-PCM from leaking when applied to the wall. By T-History method,compare the phase change temperature and latent heat of the Bio-PCM and the composite Bio-PCM. Then, in order to illustrate the thermal conductivity and work efficiency of Bio- PCM that has been improved, use numerical simulation to analyze the cross-sectional temperature changes and thermal conductivity to the impact of working efficiency after compositing with expanded graphite.In the feasibility analysis of the composite Bio-PCM applied in building, the hybrid method and the filling method can be adopted. Based on the experimental research and numerical simulation of Bio-PCM building block by hybrid method,which indicated that the performance of Bio-PCM was affected by cement mortar and this method wasn’t suitable for building envelope. Based on the numerical simulation of Bio-PCM building block by filling method, which indicated that the effect of different filling position on the heat transfer performance is smalland the method to fill in the surface of the building block is feasible. Then, by analyzing the influence factors of Bio-PCM building block, it can be explained that the phase change performance can be improved by changing the Bio-PCM thickness, ambient temperature, air convection factor and so on.In the energy simulation of composite Bio-PCM applied in building. Firstly,compare the performance of Bio-PCM and thermal insulation material, clarify the difference between them. Then, based on Enery Plus simulation of energy consumption of room in different conditions, which indicates that the Bio-PCM can not completely exert the phase change property in Shenzhen and need to change the influence factors to further improve the feasibility of the application of the project.