| 微纳米曝气滴灌系统中气泡传输特性及其影响因素分析 |
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| 引用本文： | 刘燕芳,王国萃,王传涛,张献娜,李虹辰,司炳成.微纳米曝气滴灌系统中气泡传输特性及其影响因素分析[J].农业工程学报,2023,39(17):88-96. |
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| 作者姓名： | 刘燕芳 王国萃 王传涛 张献娜 李虹辰 司炳成 |
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| 作者单位： | 鲁东大学资源与环境工程学院, 烟台 264025 |
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| 基金项目： | 国家自然科学基金项目（51909113）；国家重点研发计划项目（2022YFE0100300）；山东省重大科技创新工程（2020CXGC010808） |
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| 摘 要： | 微纳米曝气滴灌系统的水、气和溶解氧传输特性不明，限制了其在农业领域的应用。该研究旨在探索微纳米气泡在滴灌管内的传输特性，为微纳米曝气滴灌系统科学运行提供理论依据。设计0.06～0.22 MPa之间的5个滴灌系统工作压力，0.60、1.50、2.40 L/min 3个进气速率，并以不曝气为对照，通过测量滴灌管首部、中部、末端滴头的水、气出流量及水中溶解氧浓度，分析三者沿滴灌管的传输特性和均匀性，以及进气速率和工作压力对其的影响规律。结果表明：1）微纳米曝气时所有处理的滴头平均出水流量达到额定流量的98.5%及以上，出水均匀度达到96%及以上，且两指标在所有曝气和不曝气处理之间的差异均未达到显著性水平（P<0.05）。2）在适中的工作压力范围内（0.10～0.18 MPa），曝气滴灌系统平均出气流量和均匀度分别在0.13～0.23 L/h、85.50%～92.41%之间，两指标分别随进气速率的提高而提高和降低；而过高或过低的工作压力（0.22 、0.06 MPa）会导致个别滴头出气流量异常高，最终提高滴灌系统平均出气流量的同时却大大降低了出气均匀度。3）微纳米曝气滴灌系统的溶解氧浓度较不曝气有明显提高，且所有处理的溶解氧均匀度均达到95%以上；溶解氧浓度沿管道传输方向呈增大趋势，随进气速率的提高呈单峰变化；在1.5 L/min进气速率组合0.14 MPa工作压力时，滴灌系统溶解氧平均值达到最高14.45 mg/L。综合考虑水、气和溶解氧传输效果，微纳米曝气滴灌最佳运行参数为1.5 L/min进气速率组合0.14 MPa工作压力，根据出气均匀度大于85%和溶解氧均值大于12 mg/L确定适宜的工作压力范围为0.10～0.18 MPa，进气速率范围1.5～2.4 L/min。该研究可为微纳米曝气滴灌系统科学运行提供理论依据。
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| 关 键 词： | 水 气 溶解氧 微纳米气泡 曝气滴灌 均匀度 |
| 收稿时间： | 2023/4/20 0:00:00 |
| 修稿时间： | 2023/7/11 0:00:00 |
Bubble transport characteristics and their influencing factors in micro-nano aeration drip irrigation system |
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| LIU Yanfang,WANG Guocui,WANG Chuantao,ZHANG Xiann,LI Hongchen,SI Bingcheng.Bubble transport characteristics and their influencing factors in micro-nano aeration drip irrigation system[J].Transactions of the Chinese Society of Agricultural Engineering,2023,39(17):88-96. |
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| Authors: | LIU Yanfang WANG Guocui WANG Chuantao ZHANG Xiann LI Hongchen SI Bingcheng |
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| Affiliation: | College of Resources and Environment Engineering, Ludong University, Yantai 264025, China |
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| Abstract: | The transport characteristics of water, air, and oxygen are unclear in drip irrigation systems with micro-nano bubble water, limiting its application in the field of agriculture. This study improved the method of collecting and measuring water and air flowing from an emitter on a drip irrigation system with micro-nano bubble water. The flow rate of water and air was calculated for the emitter at the beginning, middle, and end of the drip tubing. In addition, the dissolved oxygen concentration of the same emitter samples was measured. Then the transport characteristics of water, air, and dissolved oxygen along the drip tubing were analyzed. The uniformity of water, air, and dissolved oxygen for the whole pipe system was calculated. The influence of air intake rate (set by micro nano bubble machine) and system operating pressure on the transport characteristics and uniformity of water, air, and dissolved oxygen was analyzed. The results showed that the micro-nano bubbles had no significant effects on the water flow rate and uniformity (P<0.05), with the average water flow rate and uniformity remaining not less than 1.97 L/h (rated flow of 2.0 L/h) and 96.02%, respectively. The influence of air intake rate and operation pressure on the average air flow rate reached a significant level (P<0.05), as well as the interaction between other factors and operation pressure, while the influence of emitter position on the average outflow flow rate did not reach a significant level (P<0.05).Within a moderate operating pressure range (0.10-0.18 MPa), the average airflow rate and uniformity ranged from 0.13-0.23 L/h and 85.50%-92.41%, respectively, increasing and decreasing with the air intake rate increasing. At high or low operating pressures (0.22, 0.06 MPa), individual emitters in the middle of the drip pipe had abnormally high air flow rates, greatly reducing the air flow uniformity while increasing the average air flow rate of the drip irrigation system. The dissolved oxygen concentration of the drip irrigation system with the micro-nano bubble water was greatly higher than that of tap water. Its mean value increased a little bit along the drip tubing. And there was a single-peak variation trend with the increase in the air intake rate. The drip emitter position, air intake rate, operation pressure, and the interaction between the latter two had significant effects on the mean value of dissolved oxygen concentration for the whole pipe system(P<0.05). When an air intake rate of 1.5 L/min was combined with an operation pressure of 0.14 MPa, the average dissolved oxygen of the drip irrigation system reached the highest of 14.45 mg/L. Taking into account the transport effects of water flow, airflow, and dissolved oxygen, the optimal operating parameters for a drip irrigation system with micro-nano bubble water were determined to be an air intake rate of 1.5 L/min and an operation pressure of 0.14 MPa. The suitable operation pressure range was 0.10-0.18 MPa and the air intake rate range was 1.5-2.4 L/min according to the airflow uniformity>85% and the average dissolved oxygen>12 mg/L. This study provides a theoretical basis for the scientific operation of drip irrigation systems with micro-nano bubble water. |
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| Keywords: | water air dissolved oxygen micro-nano bubbles aerated drip irrigation uniformity |
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