Zhang Xuelai

Supercooling and cold energy storage characteristics of nano-media in ball-packed porous structures

The presented experiments aimed to study the supercooling and cold-energy storage characteristics of nanofluids and water-based nano-media in ball-packed porous structures (BPS). Titanium dioxide nanoparticles (TiO2 NPs) measuring 20nm and 80nm were used as additives and sodium dodecyl benzene sulphonate (SDBS) was used as anionic surfactant. The experiments used different concentrations of nanofluid, distilled with BPS of different spherical diameter and different concentrations of nano-media, and were conducted 20 times. Experimental results of supercooling were analysed by statistical methods. Results show that the average and peak supercooling degrees of nanofluids and nano-media in BPS are lower than those of distilled water. For the distilled water in BPS, the supercooling degree decreases on the whole with the decrease of the ball diameter. With the same spherical diameter (8mm) of BPS, the supercooling degree of TiO2 NPs measuring 20nm is lower than the supercooling degree of distilled water in BPS. Step-cooling experiments of different concentrations of nanofluids and nano-media in BPS were also conducted. Results showed that phase transition time is reduced because of the presence of TiO2 NPs. The BPS substrate and the NPs enhance the heat transfer. Distilled water with a porous solid base and nanoparticles means the amount of cold-energy storage increases and the supercooling degree and the total time are greatly reduced. The phase transition time of distilled water is about 3.5 times that of nano-media in BPS.

Research on Development of Solar Energy and Ecology Building

Our country’s solar energy resources are extremely rich. This paper mainly introduces the research on development of solar energy and ecological building. Based on the literature analysis at home and abroad, this paper has studied the development and the application process of the solar energy in construction domain. Through studying the reference from the predecessor researches in foundation and the architecture example, this paper proposes a new plan for the union of solar energy and ecological building. The union of solar energy and ecological building will provide a wide market for the use of solar energy.