基于超声雾化的蔬菜栽培管道内雾滴沉降规律研究

为了研究风速、雾化量、温度差对蔬菜栽培管道内营养液雾气的沉降变化的影响,搭建了基于超声雾化的蔬菜栽培管道试验平台。采用单因素试验分析了风速、雾化量、温度差对管道内雾气沉降量的影响,利用二次回归正交旋转组合试验得到影响雾气沉降的因素主次顺序,并建立了营养液雾气沉降量的回归方程。随着栽培管道内雾化量的增加,沉降量总体呈上升趋势。当雾化量低于420 mL·h^-1时沉降量增加缓慢,当雾化量大于420 mL·h^-1时沉降量增加明显。随着风速逐渐增大,沉降量不断减少,风速为1.1 m·s^-1沉降量最大,风速大于1.5 m·s^-1后沉降量显著减少。沉降量随着温度差的正负水平近似对称变化,温度差绝对值增大,沉降量增加。回归模型的R²为0.734 7,模型的拟合程度较高。三个因素对蔬菜根系雾气沉降影响排序为雾化量>风速>温度差。模型求得沉降量最大值为0.063 g,最优组合雾化量为680.11 mL·h^-1,风速为1.34 m·s^-1,温度...

Study on settlement of nutrient solution in vegetable cultivation pipeline based on ultrasonic atomization

A pipeline cultivation test platform based on ultrasonic atomization was built to study the effect of wind speed, atomization amount and temperature difference on settlement of nutrient solution fog in the pipeline. The influence of wind speed, atomization amount and temperature difference on the fogging amount in the pipeline was analyzed by single factor experiment, the order of factors were obtained by quadratic regression orthogonal rotation combined test, and the regression equation of the settlement amount of nutrient solution was established. The results show that: as the amount of atomization increased, the amount of settlement generally increased. When the atomization amount was lower than 420 mL·h^-1, the settlement amount increased slowly, and when the atomization amount was more than 420 mL·h^-1, the settlement amount increased significantly. As the wind speed increased gradually, the settlement amount decreased continuously, the wind speed was 1.1 m·s^-1, the settlement amount was the largest. When the wind speed was more than 1.5 m·s^-1, the settlement amount decreased significantly. The settlement amount changed approximately symmetrically with the positive and negative levels of the temperature difference, the absolute value of the temperature difference increased, and the settlement amount increased. The R² of the regression model was 0.734 7, and the model fitted well. The effects of three factors on the settlement of vegetable roots were as follows: atomization amount>wind speed>temperature difference. The maximum settlement amount was 0.063 g, the optimum combined atomization amount was 680.11 m L·h^-1, the wind speed was 1.34 m·s^-1, and the temperature difference was 0.039 ℃ in the model. The model was verified when the atomization amount, wind speed and temperature difference were: 660 mL·h^-1, 1.5 m·s^-1, 0 ℃, 540 mL·h^-1, 1.3 m·s^-1, 0 ℃, 540 mL·h^-1, 1.7 m·s^-1, 0 ℃, the settlement amount was determined by regression model to be 0.062, 0.060, 0.056 g, and the measured values were 0.057, 0.056 and 0.051 g. The relative errors were 8.77%, 7.14% and 9.80%, respectively. The results provided a reference sequence for the rapid and effective adjustment of the root growth environment, provided a reference method for the study of other environmental factors of the root system, and provided a reference for studying the root environment in other shapes of the aeroponics device.