| Shortage of fresh water resources is a major problem that human has been faced, especially in some remote mountains and islands where lack of electricity. Solar desalination technology is an effective method to solve the supply of fresh water resources in islands, remote and power shortage regions.Solar still is suitable for the brackish water desalination of island and remote areas due to its advantages of simple structure, conveniently acquirement of raw water and economize of the conventional energy. However the popularization and application of solar still in the engineering practice of brackish water desalination is limited because of its lower operating temperature, lower water rate, lower Solar energy utilization efficiency and High equipment investment. Therefore, on the basis of the existing solar distillation technology research, changing the experimental factors is of great significance to enhance the water production and thermal efficiency. In this paper the inclined wick solar still with PCM was designed. And then the effect of inclination angle, feed flow rate and PCM on the water production was numerical and experimental researched.Experiments have been carried out to analyze the influence factors of distiller water production rate on inclined wick solar still with PCM under different experimental conditions. Experimental research was under the similar weather conditions, with the feed water flow rate for the range is from 10 to 40 L/h, incline angle are 30 ° and 45 °, respectively. The results show that the feed flow velocity and incline angle are the main factors to influence the water production rate. Water production rate decreased with the increase of the feed flow velocity. So trying to reduce the feed water flow rate would get more production within the scope of the permit, but to be sure there is enough water to evaporate in cavity body. When the incline angle is closer to the local latitude, the better of the absorption of solar radiation, which is helpful to improve the efficiency of evaporation. According to seasonal climate characteristic, different melting point of phase change materials could be chosen. Water production rate of the inclined wick solar still with PCM would be slightly lower than no PCM during the day, but at night through the phase change material release large amounts of heat energy to provide driving force for water evaporation under the condition of low temperature. The total water production could be increased nearly double in the night with heat storage material. The water production can be increased from 88% to 104% in the night. The highest total water production could reach 5.16 L/m2.The three-dimensional two-phase model of the inclined solar still was established. Present work aimed at modeling of solar still by using CFD to investigate the effect of different factors on the yield, and compared with the experimental data to analysis. With different basin temperature, velocity and incline angle of solar distiller, Evaporation condensation process in solar still were simulated. The simulation results show that the temperature difference between water film and cover increases with the basin temperature increased, thus it could increase the cooling rate. Water production decreased with the increase of flow velocity. the greater the flow velocity, the more heat loss, the lower water production. The water production with 45 ° inclination is more than when the 30 °inclination. According to the actual experiment condition data, the water production rate was simulated to calculate one day yield. Simulation results have been compared with the available experimental data. It is observed that fresh water production data between simulation and experiment are in good agreement. The maximum error is within 15% which verify the reliability of the simulation. |
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