太阳能喷灌系统供给能源与水力性能关系

为了解决太阳能喷灌系统应用中无法对喷头水力性能进行有效预测的问题,以光照强度为影响因素,太阳能喷灌系统泵出口流量、泵出口压力、喷洒射程、水量分布及系统灌溉均匀性系数为评价指标,通过在夏季典型天气25~36℃下的系统水力性能试验,寻找不同光照强度下系统喷洒水力性能的变化规律,获得系统最佳工作状态下所需光照强度.试验结果表明:随着光照强度的增大,系统流量及泵出口压力均增大,泵的流量和压力随光照强度的变化规律基本符合指数分布规律.当光照强度大于900.0 W/m²时,系统流量、泵出口压力、射程及水量分布基本保持不变.获得了平均光照强度与均匀性系数函数关系,当光照强度大于900.0 W/m²时,系统喷灌均匀系数大于88%.当光照强度为200.0~600.0 W/m²时,系统喷灌均匀系数为76%~82%.太阳能喷灌系统在光照强度大于200.0 W/m²时可正常工作.该研究为改善太阳能喷灌系统水力性能,促进太阳能喷灌系统在实际工程中的推广应用提供了参考.

Relationship between solar energy and sprinkler hydraulic performance of solar sprinkler irrigation system

Facing the shortage of energy and the limitation of water resources, the development of agricultural irrigation has been constrained, especially in some remote areas where the maximum electricity cannot be fully guaranteed. The solar sprinkler irrigation system can save energy and water. It can greatly improve the efficiency of farmland irrigation, reduce labor costs, and solve the problem of irrigation power in the areas where electricity power is in shortage. However, the hydraulic performance of solar sprinkler irrigation system, which are put into use currently, is poor, limiting the development of solar sprinkler irrigation system. In order to solve the problem that the hydraulic performance can not be effectively predicted in the application of solar sprinkler irrigation system, summer experiments on the hydraulic performance of the solar sprinkler irrigation system under typical weather were carried out, taking the solar energy intensity as the influencing factor, and taking the pump outlet flow rate, pump outlet pressure, sprinkler wet radius, water distribution and irrigation uniformity coefficient of the system as the evaluation index, to find which is the better data of the solar energy intensity. The change rule of spraying hydraulic performance under solar energy intensity was obtained, and the solar energy intensity data needed under the optimum working condition of the system was obtained. The experimental results show that system flow rate and pump outlet pressure increase with the increase of solar energy intensity, and the variation of pump flow rate and pressure with solar energy intensity basically conforms to the exponential distribution law. When the solar energy intensity is more than 800.0 W/m², the system flow rate is about 1.82 m³/h, and remain unchanged, pump outlet pressure at the same time is stable at 0.43-0.44 MPa. The sprinkler wet radius generally showed a slight upward trend which between is 8.9 m and 9.7 m with the increase of solar energy intensity. When the solar energy intensity is more than 900.0 W/m², the sprinkler wet radius fluctuates to a certain extent and keeps at about 9.2 m. When the solar energy intensity is more than 200.0 W/m², the wet radius tends to be stable. The curve shape of water distribution tends to flatten gradually from triangle with the increase of solar energy intensity. When the average solar energy intensity is about 225.7 W/m², the curve shape of water distribution tends to be trapezoidal. When the solar energy intensity is more than 900.0 W/m², the curve shape of water distribution remained basically unchanged. The function relationship between average solar energy intensity and uniformity coefficient was obtained. When the solar energy intensity is more than 900.0 W/m², the uniformity coefficient CU of sprinkler irrigation system is more than 88%. When the solar energy intensity is between 200.0 W/m² and 600.0 W/m², the uniformity coefficient of sprinkler irrigation is between 76% and 82%. The solar sprinkler irrigation system can work normally when the solar energy intensity is above 200.0 W/m². This study can provide references for realizing the combination of solar energy and agricultural machinery, improving hydraulic perfor-mance of solar sprinkler irrigation system, promoting the popularization and application of solar sprinkler irrigation system in practical projects and solving the problem of irrigation power shortage in the areas with less electricity energy.