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In order to maintain sustainable agriculture, the flow in irrigation systems needs to be managed remotely and finely to achieve efficient use of water resources. This research develops a flow measuring device that integrates measurement and control to achieve precise flow regulation under remote control. The device chooses the angular regulating valve as the actuation component to control the flow. By the experimental study of the valve body working characteristics, this paper (1) establishes the relationships among the pressure in front of the valve, the valve body opening and the pipeline flow; (2) establishes the relationship between the valve opening degree and the number of driving pulses of the stepper motor, and (3) designs the opening decision and flow measurement software. The experiment shows that the flow coefficient of the valve body is 84.61, and there is no leakage loss when closed. It also shows that the regulation curve matches the law of fast-opening features. The established relationship and the correlation coefficient between the performance parameters and the measured value are both greater than 0.99, indicating a decent performance of fitness. In a test where the pipeline pressures were 0.10, 0.20, and 0.30 MPa, the average duration of flow regulation was 62.48 s, with a maximum overshoot of 5%, and a maximum steady-state error of 6%. The experiment also showed that the higher the pressure is, the better the regulation effect is. The flow measurement error under varied pressure is below 3%. With its simple structure, fast flow regulation time, and high accuracy, this device meets the requirements of flow management in irrigation systems. It can be used in a variety of flow rate remote monitoring and control scenarios. [ABSTRACT FROM AUTHOR]

Ball valves are widely used as flow control devices wherein a hollow, perforated ball pivots to control the liquid flowing through it. Due to a simple structure and only a quarter-turn of the stem required for either a fully open or fully closed state, ball valves are known for being durable with excellent shut-off properties, albeit without offering precise flow control. V-port ball valves are used as an alternative to allow for linear and even equal percentage flow characteristics, but a robust construction is required for higher velocity working fluids in the small end opening of the V-shape; otherwise, the valve could sustain damage. In the present study, a cylinder-in-ball valve is proposed through a structural conceptual design, wherein the opening begins at the center of the flow path. The flow characteristics and flow rates according to the opening rate were quantitatively evaluated via computational fluid dynamic analysis. The results showed that the flow coefficient, CV, with a range of 1.05~109.87, increased exponentially over the opening rates of 20~100%. A numerical analysis for the multi-phase flow was performed to calculate the vapor volume fraction to confirm the effects of cavitation. In addition, an experiment was conducted on the CV values to verify the validity of applying the proposed cylinder-in-ball valve as a flow control valve. Good agreement for the CV values was obtained between the experimental and numerical results. [ABSTRACT FROM AUTHOR]

Ball valves are widely used as flow control devices wherein a hollow, perforated ball pivots to control the liquid flowing through it. Due to a simple structure and only a quarter-turn of the stem required for either a fully open or fully closed state, ball valves are known for being durable with excellent shut-off properties, albeit without offering precise flow control. V-port ball valves are used as an alternative to allow for linear and even equal percentage flow characteristics, but a robust construction is required for higher velocity working fluids in the small end opening of the V-shape; otherwise, the valve could sustain damage. In the present study, a cylinder-in-ball valve is proposed through a structural conceptual design, wherein the opening begins at the center of the flow path. The flow characteristics and flow rates according to the opening rate were quantitatively evaluated via computational fluid dynamic analysis. The results showed that the flow coefficient, CV, with a range of 1.05~109.87, increased exponentially over the opening rates of 20~100%. A numerical analysis for the multi-phase flow was performed to calculate the vapor volume fraction to confirm the effects of cavitation. In addition, an experiment was conducted on the CV values to verify the validity of applying the proposed cylinder-in-ball valve as a flow control valve. Good agreement for the CV values was obtained between the experimental and numerical results.