ENERGY MATHEMATICAL MODEL OF A SPRAYER

Abstract

The research was carried out in order to develop an energy mathematical model of a plant protection unit with a trailed sprayer, which makes it possible to optimize the parameters and operating modes, taking into account their influence on the size and loss of crop yield. For comparison with the tendencies of changes in the parameters of sprayers established in practice, computational experiments were performed using the developed mathematical model. The object of study is an analogue of MTZ-82 tractor, the main parameters of which (mass, engine power, kinematic length, etc.) can be changed, an analogue of a trailed sprayer with variable parameters (width, operating speed, tank volume, drawbar length, location of the center of mass, profile width and support wheel diameter, etc.). The optimization criterion was composite and included the sum of direct and indirect energy costs during the operation of the unit, taking into account the energy of the crop lost due to deviations from the optimal parameters and operating modes of the sprayer. Incorrect choice of unit parameters leads to yield losses, resulting from its decrease due to a violation of the deadline for performing a technological operation to protect crops from weeds, trampling down part of the crops by the unit's movers during processing, especially if there is no possibility of turning outside the field, due to soil compaction in the zone of growth and development of plant root systems. Computational experiments carried out using the developed energy mathematical model showed that an increase in sprayer coverage from 16 to 32 m at an aggregate speed of 12 km/h leads to a decrease in total energy costs from 3250 MJ/ha to 1692 MJ/ha, an increase in the unit speed from 7 to 12 km/h, with a working width of 32 m reduces the total energy costs from 1971 to 1692 MJ/ha. Reducing the width of the sprayer wheel tire profile from 0.6 to 0.2 m is accompanied by a decrease in total energy costs from 2793 MJ/ha to 1692 MJ/ha.