Experimental Study On V-trough Photovoltaic-phtocatalytic Water Purification System

In order to improve the utilization of solar energy and improve the photocatalytic efficiency, low concentrating photovoltaic and photocatalytic is combined to design a V-trough photovoltaic and photocatalytic water treatment system, which is a integrated self-sufficent system with photocatalytic wastewater treatment and photovoltaic power generation at the same time in low concentration condition. The UV light in the solar spectrum is used for the photocatalytic degradation of wastewater; visible and near infrared light reach the surface of solar module through wastewater for power generation; and far infrared light is absorbed by the recycling wastewater which makes the solar module work at lower temperature. V-type concentrator combines the advantages of low concentrator and non-concetrator, which can use the direct and scattered sun light with low cost and simple manufacturing technology and has high light utilization efficiency. Comparing with the non-concentration, low concentration can increase photovoltaic generation power and photocatalytic efficiency.First of all, a solar simulator and a small SOLWAT system is built to comparatively analyze its optical performance and the performance of photocatalytic and photovoltaic power generation in diffenrent conditions. Secondly, V-trough SOLWAT system is constructed, and the optical structure is analyzed in theory, and the concentration ratio is calculated, and the real concentration ratio is measured, and the effects of the overall system spectral transmittance for the system electrical performance is analyzed. Finally, a non-concentrating SOLWAT system is constructed to analyze the performance of photocatalytic and photovoltaic power generation in contrast with the V-trough SOLWAT system.The results of the study show that: 1. Under the simulative light source, with the increase of the concentration of catalyst, the photocatalytic reaction rate gradually increases, but the concentration of the catalyst increase to certain extent, the increase of reaction rate is not obvious. With the increase of light intensity, the reaction rate gradually increase; 2. The theoretical concentration ratio of V-type concentrator is 2.64 and the real concentration ratio is 2.34; 3. With the increase of the initial pollutant concentration the full decolorization time of V-trough SOLWAT system the non condensing system is respectively reduced by 33.3%, 42.9% and 54.5% compared to the non-concentrating SOLWAT system. With the increase of the concentration of catalyst, the full decolorization time of V-trough SOLWAT system is respectively reduced by 47.4%, 62.5% and 33.3% compared to the non-concentrating system; 4. Both non-concetrating and V-trough photocatalytic degradation reactions are accorded with the first-order kinetics. With the increase of the concentration of catalyst, reaction kinetics constants of non-concetrating system increase gradually, while the reaction kinetic constant of the V-trough system increases first and then decreases; 5. The maximum output power and short-circuit current of V-trough system are greater than those of the reference system, and are about 2 times of non-concentrating system. Higher output power can not only meet the need of the operating system, but also excessive electricity can be stored.