手持式风送授粉机工作参数优化与试验

针对果树授粉作业普遍存在授粉量大、授粉作业不均匀等现象,采用Box-Benhnken的中心组合试验设计理论对风送式授粉作业工作参数作优化研究。以手持式风送授粉机为研究对象,以喷管直径、收缩管直径、电机电压等工作参数为影响因素,以花粉授粉量、喷管出口固相质量浓度、花粉覆盖率为目标函数,建立两者之间的多元数学回归模型,探索各因素之间的影响规律及最佳水平组合。利用Design-Expert 8.0.6软件的回归分析法和响应面分析法对模型进行优化分析,得到风送式授粉机最优工作参数。性能试验结果表明:喷粉量、固相质量浓度影响因素显著顺序依次为喷管直径、电机电压、收缩管直径;覆盖率影响因素显著顺序依次为电机电压、收缩管直径、喷管直径;最优参数组合为喷管直径为5 mm、收缩管直径为7.5 mm、电机电压为8.0 V,对应的花粉喷粉量、固相质量浓度、覆盖率分别为1.70 g/min、17.28 g/m3、77.71%,且各性能指标与理论优化值相对误差均小于6%。田间试验结果表明:猕猴桃花朵柱头的覆盖率为67.11%,与性能试验结果相比相对误差小于16%。研究结果可为进一步完善风送授粉机的结构设计和作业参数优化提供参考。

Parameter optimization and experiment of air-assisted pollination device

Abstract: The planting area of orchard and fruit production in China is at the top in the world, but there are the disadvantages of the late development of orchard pollination device and the relatively low level of mechanization, so poor pollination has become the main factor influencing the improvement of orchard yield and quality, and seriously hampered the development of Chinese fruit industry. Pollination is the key process in the fruit production, and sufficient and well-distributed pollination can be helpful to increase the outputs and improve the quality. Artificial pollination is widely used in fruit production in recent years, which is labor intensive and with low productivity and process restricted, and cannot adapt to large-scale production. Thus, in order to make full use of the pollen, the technique and machine used for the pollination are needed. Pollination technique, particularly air-assisted pollination technique, is an inevitable trend for fruit production. In order to further study the pollination technique, the pollination testbed was designed. The testbed consisted of a pollination device, direct current stabilized power supply, definite time relay and glassslid. The nozzle diameter, shrinkage pipe diameter and motor voltage were taken as the influencing factors. The dusting rate, solid mass concentration and pollen coverage were used as test indices in the experimental study. Orthogonal rotational quadratic combination test with three factors and three levels was made to evaluate the combined influence of the factors on the test index value, and then regression equations to describe the relationships between the factors and each assessment index were established by using the regression analysis and response surface analysis with the software Design-Expert 8.0.6. The optimum combination of input parameters was obtained and verified, and the experimental verification of the mathematical model was also conducted. The results showed that trial factors had great effects. The significant effects of nozzle diameter, motor voltage and shrinkage pipe diameter on reducing the dusting rate were in a decreasing order. The significant effects of nozzle diameter, motor voltage and shrinkage pipe diameter on reducing solid mass concentration were in a decreasing order. The significant effects of motor voltage, shrinkage pipe diameter and nozzle diameter on increasing pollen coverage were in a decreasing order. The best model of the integrated pollination parameters was as follows: when the nozzle diameter was 5 mm, the shrinkage pipe diameter was 7.5 mm and motor voltage was 8.0 V, dusting rate was 1.70 g/min, solid mass concentration was 17.28 g/m3, and pollen coverage was 77.71%. Through comparing the mathematical model and the experimental result, it turned out that the relative errors of all the property indices between the two were less than 6%, which meant that the model established was useful and could be used for predicting and optimizing. The field experiment was conducted in a kiwi grove where "Hongyang" kiwi trees were grown, and the results showed that pollen coverage was 67.11%. Compared with the field result, the laboratory experiment turned out that the error range was less than 16%. It can provide theoretical and experimental basis for further study of pollination mechanism and developing pollination machinery, and also greatly promote the progress of industrialization and large-scale manufacture.