低压灌溉系统中文丘里施肥器吸肥性能试验分析

水肥一体化灌溉施肥技术是现代农业的一个重要标志,在一些发达国家已经作为一种标准作业方式进行运用。低压滴灌施肥技术作为一种能量优化的水肥一体化灌溉施肥技术,不仅具备常压滴灌施肥技术的优点,还可以降低灌溉施肥系统的成本,是未来滴灌发展的重要发展方向。为此,在基于CFD数值模拟方法得出满足低压灌溉系统的文丘里施肥器结构参数的基础上,以优化后的结构参数试制出一款文丘里施肥器样品,并在进口压力为0~0.1MPa的范围内进行试验。结果表明:进口流量比、吸肥流量和肥液浓度都是随着进口压力的增加而增大,且当进口压力为0.05MPa时,进口流量比达到最大,为11.17%;当进口压力为0.07MPa时,吸肥流量达到最大,为0.245m^3/h;当进口压力为0.0 5 MPa时,肥液浓度达到最大,为1 0.0 4%。该肥液浓度条件能满足实际灌溉要求,在获得同等或更高的吸肥性能时具有更低的工作进口压力,更适用于低压滴灌系统,为低压灌溉的研究提供了参考。

Experiment and Analysis of Venturi Injector Fertilizer Performance in Low Pressure Irrigation System

The integration of irrigation and fertilization technology is an important symbol of modern agriculture. It has become a standard method of operation in developed countries. Low pressure drip irrigation is a kind of water and fertilizer integrated irrigation technology with optimized energy utilization. Not only has all the advantages of ordinary pressure drip irrigation technology, but also can reduce the construction cost and operating cost of irrigation system. It is an important direction of the development of drip irrigation technology in the future. Based on CFD numerical method, the structure parameters of Venturi injector were optimized. And the Venturi injector sample was produced by these structure parameters. The Venturi injector sample was tested with inlet pressure from 0 to 0.1MPa. The data gotten from the experiment were analysed and the results showed that: with the increase of inlet pressure, the rate of fertilizer absorption , the ratio of inlet flow and the fertilizer concentration increased. When the inlet pressure was 0.05MPa, the inlet flow ratio reached the maximum, which is 11.17%. When the inlet pressure was 0.07MPa, the maximum fertilizer absorption rate was 0.245 m 3 /h. When the inlet pressure was 0.05 MPa, the fertilizer concentration reached the maximum, which was 10.04%. The fertilizer concentration condition could meet the requirement of actual irrigation. The Venturi injector needed much lower water inlet pressure to obtain the higher fertilizer absorption performance and it was more suitable for low pressure irrigation system. It also provided some references for the study of low pressure irrigation.