Influence of illumination intensity on performance of photovoltaic pumping irrigation system
TAN Minggao1,2,YUN Tianping1*,WU Xianfang3,LIU Houlin1,2,MA Haochen4
1. National Research Center of Pumps, Jiangsu University, Zhenjiang, Jiangsu 212013, China; 2. Zhenjiang Fluid Engineering Equipment Technology Research Institute, Jiangsu University, Zhenjiang, Jiangsu 212013, China; 3. School of Energy and Power Enginee-ring, Jiangsu University, Zhenjiang, Jiangsu 212013, China; 4. School of Mechanical Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, China
Abstract:In order to study the effect of the illumination intensity change on no photovoltaic battery working cha-racteristic of the irrigation system, a battery-less photovoltaic irrigation system test was set up, including rotary sprinklers, photovoltaic pumps, inverters, photovoltaic panels and other components. The various operating data of the system at different illumination intensities were obtained. The results show that the fluctuation of sprinkler operating pressure, sprinkler range and sprinkler rotation period are affected by the illumination intensity variation at higher illumination intensity, but at lower illumination intensity, but at lower illconination intensity, the range and pressure of the sprinkler increase with the light intensity increa-sing. Besides, the variation trend of the range is consistent with that of working pressure, but the variation trend of the rotation period is contrary to that of working pressure. The sprinkler pressure is coordinated with the pump outlet pressure and photovoltaic panel output power. The system operation parameters reach the threshold value when the illumination intensity is around 1 000 W/m2. The sprinkler maximum range and working pressure are 9.8 m and 0.44 MPa. The pump maximum flow and outlet pressure are 1.68 m3/h and 0.45 MPa. Before the threshold reaches, the pump and sprinkler have a larger operation parameters range, which are mainly affected by illumination intensity. When the light intensity is larger than the threshold the influence factors are dominated by the illumination intensity and temperature. The operation parameters change smaller at this time. The illumination intensity is a gain factor and the temperature is a depreciation factor. At lower illumination intensity, the combined average sprinkler irrigation intensity increases with the illumination intensity increasing. At higher light intensity, the combined average sprinkler irrigation intensity fluctuates with the light intensity, which is consistent with the variation trend of photovoltaic module output power. As the illumination intensity increases, the uniformity coefficients of sprinkler irrigation and distribution monotonically approach to the highest value, and the highest value of the uniformity coefficient of sprinkler irrigation reaches 0.88.