Effect Of Gold Sol On Solar Thermal Conversion Efficiency

Solar energy is a clean and renewable energy, and it has important significance for the progress and development of society. Solar steam power generation has a series of advantages, such as economy, high heat absorption, cleaning and so on. Therefore, solar power generation is an important and feasible method of thermoelectric conversion. With the further research on the technology of solar thermal conversion, the efficiency of solar energy conversion into steam energy has become the obstacle of the new generation of high efficiency technology. Recently, some studies have showed that the addition of composite nanoparticles in water can significantly increase the efficiency of light and heat transfer. Sunlight on the dispersion of composite nanoparticles in water, the water around the particles can be quickly generated vapor and the overall water temperature is not required to reach the boiling state. In order to study the effect of aurosol on the thermal conversion efficiency, the aurosol was prepared to contrast to the nano-sized noble metal composite particles.In this paper, aurosol was prepared by the method of aqueous phase, and the average size of the prepared nanoparticles tested by zeta potential was 50 nm. At the same time, the aurosol was characterized by UV visible light, and its UV is absorption spectrum was obtained. The absorption peak of 532 nm was matched with the absorption peak of 50 nm nanoparticles in the literature. Irradiated by sunlight, it was found that it could not convert the water around the nanoparticle to steam and the reason was analyzed. The size of nanoparticles becomes larger so that the ability of visible light absorption is reduced.The temperature history of the aqueous solution with different proportion of aurosol was also compared, and we observe the aqueous solution which join aerosol its temperature rise more quickly and achieve higher temperature than that of no aurosol, and with the increase of the proportion of aerosol the rising speed and the final temperature of greater. After a lot of experiments the average thermal conversion efficiency was obtained, and the effect of different proportion of aurosol on the efficiency of light and heat transfer was quantitatively compared.The absorption ability of nanoparticles with different diameters to different wavelengths was simulated. It was found that with the increase of the size of the gold nanoparticles from 10 nm to 100 nm, the absorption peak in the visible range move to the long wave, however, when the size of the nanoparticles was larger than 100 nm, the absorption peak hopping to the ultraviolet spectral range. This is a good explanation for the decrease of solar absorption capacity after agglomeration.