Experimental Study On The Vaporization And Release Of Greenhouse Pesticides At Close Range

Pest control is an important task in field work.At present,China's pesticide application technology is relatively backward,and the utilization rate of pesticides is low.The traditional spraying machine in China is a knapsack manual sprayer,which is still used in some areas.At present,some researches on plant protection of tall crops have been carried out in the field of agricultural aviation.However,there are still few studies on the small-scale application technology of solar greenhouse.The traditional method is not only inefficient,but also easy to cause poisoning and other phenomena in the closed environment.Therefore,it is necessary to study the application mechanism of solar greenhouse.This research is based on the physical phenomenon of phase behavior change,change the velocity of fluid and the pressure,make solution at room temperature phase change,from liquid to gas,through the arrangement of gas pipeline system in greenhouse,inside to the greenhouse,spraying pesticides on crops,and because the gas can be suspended in the environment relatively long time,make better plant protection effect.First of all,the system is divided into three parts: the vaporization device,the pharmaceutical liquid control system and the gas transmission device,among which the vaporization device is the core component,including the infusion tube,the air inlet,the air flow pipeline,the gas-liquid cavitation pipeline and the vaporization nozzle.The air inlet is based on the basic principle of Bernoulli equation,which controls the temperature constant,changes the size of the aperture to change the airflow velocity,so as to form negative pressure.The gas-liquid cavitation pipeline is equipped with the conditions of liquid cavitation through the negative pressure here,and there are small bubbles in the liquid flow,so that the liquid in the device is constantly vaporized,and then ejected from the nozzle,forming the phenomenon of vaporization.According to the theoretical derivation,the relevant parameters of the vaporizer are obtained.CFD software was used to perform flow field analysis and a Realizable k-modal was selected.Through the generality of the k-model,the related equations,namely the transport equation,the continuity equation,the momentum equation,the energy equation and the governing equation,were derived.A new pesticide evaporation device model was designed by using relevant parameters of the device,and Fluent was used for analysis.The installation position,liquid velocity,liquid level difference and temperature of the vaporizer are controlled by the comparison method and the control variable method,and the suitable vaporization parameters are selected.Through a series of experiments,the conditions for better vaporization effect are analyzed and verified.