自适应滴灌灌水器的水力性能试验

Hydraulic performance experiment of an adaptive drip irrigation emitter

为检验自适应滴灌灌水器的流量自动调节效果,根据自适应滴灌灌水器的工作原理,利用负压吸气泵模拟土壤负压,进行了AD-1型自适应滴灌灌水器在流量补偿、流量自适应2种工作模式的流量均匀性、供水压力-流量关系、模拟土壤负压-流量关系等水力性能试验与研究,并分析了其适宜的工作压力。结果表明:AD-1型自适应滴灌灌水器增添的滴水状态控制结构,不仅保留了常规滴灌灌水器的流量补偿特点,还增添了感知土壤水分含量、智能化控制灌溉和流量自动调节的多重使用功效。在流量补偿模式下,灌水器在额定供水压力100kPa时的平均流量为14.71L/h,且流量均匀度高,流量偏差系数为9.79%;在流量自适应模式下,灌水器的流量均匀度基本不变,在供水压力30kPa和土壤负压最小值20kPa的共同作用时即可开始正常工作,并确定出最小、最大的适宜供水压力分别为30、50kPa。在适宜供水压力30～50kPa范围内,灌水器能根据土壤实际水分状况在0～11.22L/h之间实时、自动调节滴水流量,改变了常规灌水器被动出水的工作方式,真正实现作物、土壤的按需主动连续取水,明显地提高了节水灌溉设备的精准灌溉水平,既保证了作物正常生长的适宜土壤水分,又促进了灌溉系统应用模式向智能化、自动化方向的进一步发展。

An adaptive drip irrigation emitter is a new type of emitter which uses the multi-use function of flow compensation and the flow adaptive. In order to examine the effect of self-adjustment automatically on an adaptive drip irrigation emitter, we studied the hydraulic performance of the type of AD-1 adaptive drip irrigation emitter under two different operating modes of the flow compensation and the flow adaptive according to the working mechanism of the adaptive drip irrigation emitter by using the negative pressure suction pump to simulate the soil suction. The tests examined the flow rate uniformity, the relation between the supply water pressure and drip flow, and the relation between simulated soil negative pressure and drip flow on the adaptive drip irrigation emitter which the simulated soil negative pressure was formed by suction pump. At the same time, we had analyzed the suitable supply water pressure. The results showed that： the adding of drip state control structure not only retained the general flow compensation characteristic of drip irrigation emitter, but also added in advantages including multi-use functions of soil moisture monitoring, intelligent controlling irrigation and automatic adjustment of drip flow. At the mode of flow compensation, the flow rate of emitter was 14.71 L/h, the coefficient of uniformity was higher, the coefficient of flow deviation was 9.79% when the supply water pressure was rated 100 kPa. At the mode of flow adaptive, the emitter can begin working normally when the two pressures were acting together, and when the supply water pressure was only 30 kPa and the minimum soil suction of 20 kPa. The coefficient of flow uniformity also stayed steady. Then we determined the minimum and the maximum suitable water supply pressure was 30 and 50 kPa respectively. Moreover, it can adjust the drip flow rate automatically and in a timely manner at the range of 0-11.22 L/h according to the actual soil moisture status at the range of suitable water supply pressure 30-50 kPa. Unlike conventional irrigation emitters, the adaptive drip irrigation emitter can better change the working mode of dripping water passively and the technology of the irrigation system was improved to the level of accurate and precision irrigation, and achieved the aim of fetching water initiatively according to the needs of the crop and soil. Therefore, all of above characteristics are not only ensuring the supply of the suitable soil moisture during the normal growth of a crop, but also promoting the further development of an irrigation system application mode in the direction of more intelligence and more automation.