The Preparation Of Composite Phase Change Material And Application In Building Palisade Structure

With the growing of the global energy crisis, it urges people to explore the new technology or new method actively to use the energy effectively and save the energy. In the architecture field, the realization of storage and utilization of the latent heat energy during the phase change process of the phase change materials can reduce energy consumption. That is one of the important measures for energy conservation in buildings .This research mainly includes: the research of phase change material used in exterior wall insulation and interior wall heat preservation, the packing technology research of loading type composite phase change material, the preparation of paraffin wax microcapsule, the preparation and application of composite phase change materials'saving energy mortar.The main conclusions are as follows:1. This experiment has been used the 46 # paraffin, butyl stearate, tetradecyl alcohol, cetyl alcohol and capric acid as phase change materials to process the mix experiment with the improved method of cooling curve. Through the DSC test , the results showed that 75%(mass fraction) paraffin and 25%(mass fraction) buty stearate can form the compound materials with phase change temperature at 43℃,and 95% (mass fraction) buty stearate plus 5%(mass fraction) cetyl alcohol can form the compound materials which phase change temperature is 23℃.2. A kind of packaged composite phase change material was prepared using expanded perlite, paraffin, urea formaldehyde hybrids by using vacuum-impregnation process. This kind of packing composite phase change material was made of paraffin as a dispersed phase change material and expanded perlite as a supporting material, moreover, urea-formaldehyde resins as membrane materials to be applied to the porous surface of expanded perlite(EP). The weight method test showed that leakage rate of package composite phase change materials significantly reduced.The leakage rates of the load composite phase change materials which were not encapsulated were above 25%, but the leakage rates of the load composite phase change materials which were encapsulated were obviously lower which were all under 15%.The results of Differential Scanning Calorimetry (DSC) test showed that package composite phase change materials had stable thermal effect. When the ratio of paraffin/expansion perlite was 2:1, the enthalpy of paraffin/expansion perlite load composite phase change materials reduced by 68.97 kJ/kg, and the enthalpy of the composite phase change materials which were encapsulated by urea-formaldehyde resin membrane materials only reduced by 10.91 kJ/kg .The SEM images of Packaged composite phase change materials showed that expansion perlite had been packaged by the film, and the thermogravimetric analysis tests (TGA) indicated that the decomposition temperature of Urea-formaldehyde resin curing film was 170℃~ 350℃, and the work environment temperature of package composite phase change materials was 100℃below.Therefore, packaged composite phase change materials have good thermal stability in the work environment temperature.3. A paraffin microcapsule was prepared by the situ polymerization method using melting paraffin as core material and urea-formaldehyde resins as shell material respectively. These results mainly showed that Mass ratio of core and shell was 1:1, the reaction temperature was 50℃, stirring speed was 700 r/min, and 15% NaCl was 10ml. Finally paraffin microcapsule package rate was 40.74%.4. 43℃, 23℃package composite phase change materials were applied to energy-saving mortar with other building materials together.Taking the building materials to conduct performance test.We can find that the basic performances of these building materials all reached the standards. In addition to the perpermance of heat insulation and preserving heat all increased. The tests made the different types of phase change energy saving mortar belong to 43℃rase from 20℃up to 45℃, including blank perlite, SY-1.0, SY-1.5, SY-2.0 and FSY-2.0,and the time they used respectively was 215 min, 358 min, 433 min, 491 min and 516 min, the heat insulation effects of saving energy mortar which were added of phase change materials were remarkable. Made SY-2.0 and FSY-2.0 experienced cold and heat cycle for 100 times, then made SY-2.0, FSY-2.0 rase from 20℃up to 45℃, and the time they used respectively was 385min and 490min, therefore, the persistenced heat insulation of FSY-2.0 was superior than 2.0 SY's. The tests made the different types of phase change energy saving mortar belong to 23℃droped from 45℃to 20℃, including blank perlite, YC-1.0, YC-1.5, YC-2.0 and FYC-2.0, and the time they used respectively was 45min, 54min, 70min, 100min and 105min, the heat preservation effects of saving energy mortar which were added of phase change materials were remarkable. Made YC-2.0 and FYC-2.0 experienced cold and heat cycle for 100 times, then made YC-2.0 and FYC-2.0 droped from 45℃to 20℃, and the time they used respectively was 68min and 100min, therefore, the persistenced heat preservation of FYC-2.0 was superior than YC-2.0's.