Flow Measurement Using Bypass Flow Meters for Smart Farming Applications

Abstract

Background and Objectives: Accurate flow measurement is essential in order to improve water efficiency and productivity in any irrigation system. Precision irrigation is a technique that optimizes water usage by utilizing technology to deliver the right amount of water according to crop requirement. In smart farming, this approach relies on precise water monitoring and control. However, traditional flow meters often pose significant challenges due to their high installation costs, particularly for large-diameter pipes. Bypass flow meter (BPF meter) offers a cost-effective alternative resolution for flow measurement. BPF meter measures flow in large-diameter pipes by diverting a portion of the flow through a smaller bypass pipe mounted with a flow meter. Although the BPF technique has been around for some time, its application and performance in flow measurement are still underexplored. Therefore, this study sought to fill the gap by presenting the concept, performance, and practical implementation of BPF meter as a cost-effective and accessible alternative for water flow measurement in smart farming applications.

Methodology: Experiments were conducted using BPF meters with different main pipe to bypass pipe diameter ratios (D/d = 2:1, 2.5:1, 3:1, and 4:1). To ensure consistency across experimental settings, the lengths of all pipes were fixed to focus on the examination of the effect of the diameter ratio on BPF meter performance. The bypass flow rate (Q_BP) and the total flow rate (Q) were quantified under regulated experimental settings. Each pipe diameter configuration was tested at different flow rates, with each flow rate subjected to a minimum of three tests to verify dependability and to reduce experimental errors. The relationship between Q_BP and Q was then analyzed and is expressed by the equation Q=KQ_BP, where K is the loss coefficient, which is dependent on pipe configuration. Statistical parameters, including the coefficient of determination (R²), root mean square error (RMSE), and mean percentage error (MPE) were employed to evaluate the accuracy and reliability of the model for each configuration.

Main Results: The main findings reveal that the total flow rate (Q) is directly proportional to the bypass flow rate (Q_BP), and this relationship is influenced by the pipe diameter ratio (D/d). The findings indicate a robust linear relationship between Q and Q_BP (R² > 0.99), with minor errors across all configurations. Larger D/d ratios demonstrate higher K values, indicating increased sensitivity to bypass flow measurement. The consistency of the K values across pipe configurations supports the robustness of the proposed calibrated model and illustrates the adaptability of the BPF meter for varying pipe diameters. While the BPF meter maintains accuracy across all pipe configurations, larger pipe diameters are correlated with minor increase in the measurement variability. Therefore, the selection of a suitable pipe diameter ratio (D/d) is essential for maintaining the accuracy of BPF meter. By considering these design aspects, BPF meter could be accurately calibrated to meet the different demands.

Conclusions: The study validated the suitability of BPF meters for accurate water flow measurement in smart farming applications. The variation of the K coefficient across different D/d ratios illustrates the flexibility in adapting the BPF meter for different applications. The results also show that the choice of pipe diameter (D/d ratio) significantly affects the accuracy and applicability of BPF meter. Smaller D/d ratios are more suitable for systems with lower flow rates, while larger ratios are more suitable for higher flow rate systems. Nevertheless, the calibration equation ensures that BPF meter can be effectively used in various irrigation applications.

Practical Application: This study provides a practical framework for the implementation of BPF meter as a viable and cost-efficient alternative to conventional flow measurement devices. BPF meter can be practically applied to enhance water management in smart farming or any irrigation applications. Farmers would be able to monitor and regulate water usage in real-time through the use of BPF meter. Integrating BPF meter with IoT systems would allow precision irrigation to be implemented, optimizing water allocation to crops according to plant water requirements, hence improving productivity, conserving water resources, and providing significant benefits to agricultural systems with limited resources.