| Passive energy-saving technologies,which are promoted to be adopted in buildings to reduce the energy consumption,is one of the hot spots in the research field of green and energy-saving building.Using materials with special properties as inner surface material to passively adjust the air temperature and relative humidity was considered as an effective energy-saving technology.Hygroscopic material and composite Phase Change and Humidity Control Material(PCHCM)are two typical examples.They both have specific mechanism of heat or mass transfer that can be used to buffer the variation of temperature and humidity and consequently reduce the building load so that more and more attention has been paid.The impact of the hygroscopic material and PCHCM on indoor temperature and humidty was called heat and moisture buffering phenomenonnd.In the research field,how to calculate the moisture buffering phenomenon with an easier and quicker method and how to simulate the heat,enthalpy and vapor flux through the PCHCM and predict the effect of the application of PCHCM in real building under different climates were two cutting-edge problems.Taking this as a starting point,this dissertation launched a study based on the relevant theoretical knowledge and research methods of the indoor heat and moisture buffering phenomenon.Firstly,an adaptive method to calculate moisture uptake/release was got based on the definition of moisture buffer value(MB V)and a theoretical derivation of moisture transfer.The method takes the MBV of hygroscopic material,which can be easily got by the Two-bottle method,and a correction factor of humidity cycles as parameters.The method is rapid and convenient compared to common numerical models.Comparison of the calculation examples demonstrated its accuracy with an error ratio less than 5%.The calculation of annual moisture uptake of the porous surface under the real outdoor climate condition shows practicality.Then,an improved way to simulate the moisture uptake/release using the MBV of surface material was built.The method used the effective humidity capacitance model,in which the EC value of given zone was got by MBV and open area of inner surfaces.A more accurate and effective rules was put forward,in comparison of relative humidity and latent load with HAMT model.Tests with different materials and various condition were completed.The results showed that the way had good adaptive ability in aspect of latent energy saving simulation.Then,a coupled model called coupled HAM-Enthalpy model that can calculate the heat and moisture distribution inside the PCHCM was proposed.The relations and equations of heat and moisture transfer model(HAMT)and enthalpy method was adopted.The model could get exact results on the suitable condition of the space and time discretion.Based on the analysis of the influence of porosity and undercooling degree on the properties,the advantages of PCHCM in function and space integration are verified.Finally,climates were classified into four different PCHCM suitablility levels according to the analysis of outdoor humidity ratio and temperature.The inner hygrothermal environment and energy consumption of case building under climates of Beijing,Paris,Atlanta,and Guangzhou was simulated.The results showed that using PCHCM can effectively adjust indoor temperature and relative humidty,and the thermal loads could consequently decresased about 15.81%/21.84%/27.10%/8.76%seperately。This dissertation takes the heat and moisture buffering phenomenon as the subject.The method of uptake/release calculation using MBV was updated.The research gap in the area of the effect of PCHCM in building under different climates was primarily filled.Conclusions and results in the paper are meaningful for the study on the buffering phenomenon,and they are also helpful to promote the application of passive energy-saving materials in green building.The whole thesis contains about 62 000 words,99pictures and charts... |
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