| Freshwater is a basic demand for human survival,and solar heating is an important way for desalination.However,The current solar heat method desalination can only be heat vaporization that receives low solar energy flux.In this study,an external reflector is added to the bottom of a device for collecting solar radiation with a large area of heat collecting plate,so that the temperature of the working medium can be continuously vaporized at the boiling point.Under the condition of irradiance variation,the calculation optimization and experimental study were carried out on the solar heatconcentrated vaporizing device enhanced by external reflector and the condition of component temperature,energy and freshwater yield.The main research work and conclusions are as follows,(1)The calculation model of solar radiation obtained by the system is established.Calculated the energy received by the device in different azimuth angles,mirror tilt angles,and seasons.The results show that in winter,the smaller the tilt angle of the mirror,the higher the energy received.When the mirror is tilted 15°,the solar heatconcentrated vaporizing device receives the highest energy at azimuth 0°.When the azimuth angle is 0°,the solar heat-concentrated vaporizing device receives the highest energy at mirror tilt 15°.The solar heat-concentrated vaporizing device receives the highest energy at mirror tilt 15° and azimuth angle 0°.(2)Based on the fixed tilt angle,azimuth angle and seasons,the optimal tilt angle and azimuth angle of the solar heat-concentrated vaporizing system for desalination with external reflectors enhancement in different seasons cannot be accurately obtained.In the whole year,different tilt angle,azimuth angle,reflection energy and total energy obtained by the device are calculated.The results show that reflection energy can be obtained that the best azimuth angles in spring and winter are-90 °,the best mirror tilt angles are 30-35 ° and 15 °,respectively.The best azimuth angles in summer and autumn are 0 °,the best mirror tilt angles is 45 ° and 30 °,respectively.The best azimuth angles in spring,summer,winter and autumn are 0 °,the best mirror tilt angles is 30-35°,45°,30° and 15°,respectively,which receives the highest energy for the solar heatconcentrated vaporizing device.(3)Experimental research on the energy,component temperature,and freshwater yield obtained with or without a reflector.The results show that the average temperature of the heat collecting plate is 126.81 in summer and 143.13 with reflector,increasing by 12.9%.The average temperature of the heat collecting plate is 128.51,and with reflector is 142.43,increasing by 10.8% in winter.After the addition of reflector,the temperature of the metal steam generator pipe can last for more than 5h,and the average temperature is 106.75 and 104.24,respectively.The solar heatconcentrated vaporizing device produces about 5.5-8.5kg of freshwater throughout the day,and about 10-13 kg of freshwater produces after the addition of reflector. |
