| The development of society and economy has been restricted by shortage of water resource significantly.Desalt seawater is an efficient method to alleviate the phenomenon.As a renewable energy with many advantages,i.e.environment-friendly,sustainable and long-term used,the solar has been utilized to deal with energy shortage and environmental pollution more frequently.Therefore,the combination of solar energy technology and fresh water produced by desalination technology is widely used in the water-saving area.Based on the photovoltaic and thermal technology,this paper designs a set of desalination system to output both fresh water and electricity simultaneously.The specific work of theoretical analysis and experimental research is as follows:1)The first part of paper introduces the process of system in detail,especially for the basic structure and working principle of C-PV/T seawater desalination system.The design scheme and parameters of each subsystem is finished to ensure the stable operation of the system.Comparing the simulation results of the system under different concentration ratio,the ratio of compound parabolic concentrator is selected to be 4.For improving the water temperature,a proper seawater desalination device is designed,and the PV/T modules are connected in series.There are 17 points to collect data in the all system.The industrial personal computer is in charge of recording data and controlling the system.2)The energy transfer model of the low concentrating solar desalination system consists of two parts: concentrating photovoltaic thermal system and desalination system.Further,the theoretical model of each subsystem has been established by heat transfer theory,and the influence factors of module efficiency and water production have been study also.The results show that the electrical efficiency decreases linearly with the rising of module temperature.The thermal efficiency is influenced by the radiation intensity,inlet refrigerant temperature and wind speeds,and the radiation intensity is the main factor to affect the system thermal efficiency.With the increase of inlet refrigerant temperature and the temperature difference between the seawater and cover,the water production also increases.It's greatly obvious that the water producing capacity is much stronger in the high temperature section.3)The last part is to conduct experiments of solar desalination,record and deal with the experimental data.The performance curve is built by commercial software(Origin 8.0),and the influence factors of system performance is analyzed according to which.Based on the experimental results,we can conclude that the cooling heat exchange channel is the main factor to the PV/T performance.And,the glass heat flow can greatly enhance the heat output and is more applicable to be the heating front end of seawater desalination system.Moreover,the water production of distillation is mainly controlled by the temperature difference and seawater temperature.It is inferred that the temperature difference is the main driving force for seawater evaporation from experimental data.The production is also influenced by the cover slope and cover thickness.When the cover angle is set as45°,the working medium can absorb more energy from the C-PV/T module with a low inlet flow.And it can produce 13.33 L freshwater,which is 2L more than that as 35°.When the flow is 100L/h,the heat transfer channel have a great cooling effect,and the power generation is twice as much as it in the flow rate of 80L/h consequently.General y,the device of C-PV/T solar desalination system has the advantage of Simple structure,great performance,and can output both fresh water and electricity simultaneously.Therefore,it can supply theoretical basis and technical support to the new solar desalination system. |
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