Modeling a pneumohydraulic sprayer for irrigation and fertigation

Abstract

The aim of the research was to increase the efficiency of use and the ability to control liquid spraying when creating artificial rain in medium to reduce energy consumption, to increase the reliability of the device for irrigation of crops, which combines additional processing of plants with various technologies for growing them by creating the necessary conditions for the formation of a water-air stream due to substantiation of the structural and geometric design parameters of sprayer. The most common irrigation method called the sprinkling is analyzed. The need to increase the economic efficiency of spray nozzle designs to improve the quality of artificial rain is shown. A fundamentally new scheme of the spraying device for innovative irrigation technologies and a mathematical model for the theoretical and technological substantiation of its main parameters: the diameters of the nozzles of the water and air nozzles, the diameter and length of the mixing chamber, as well as the necessary water and air pressures, are developed. The rationale for the design decisions of the pneumohydraulic sprayer is given. The destruction of the continuity of the liquid in the atomizer is considered taking into account the parameter of its strength during the interaction of heterogeneous phases of water and air. In this case, the air supply for spraying the liquid can be carried out either by force or by ejection. The algorithm for calculating the parameters of the spraying device is executed and works in a spreadsheet (EXCEL or WPS) using the mathematical expressions justified for the main structural and technological parameters of the device. The initial data are the pressure of water р1 and air р2 at the inlet of the sprayer, the required water flow rate G1 and the ejection coefficient u. The calculations take into account the flow coefficients of water and air µ, the gas constant R and the air temperature Т. The calculation results are displayed in EXCEL tables. Based on the results of mathematical modeling of the operation of the pneumohydraulic sprayer there were obtained the graphical dependencies to optimize its technological parameters and design solutions for the development, manufacture of a pneumohydraulic sprayer prototype and its experimental testing to obtain droplets of artificial rain of various sizes during irrigation and fertigation of crops, which will contribute to a successful solution of discussed agroindustrial complex problems.