Avaliação da eficiência de sistemas de bombeamento em lavouras de arroz irrigado na fronteira oeste do Rio Grande do Sul

Abstract

Given the national and mainly regional context, flood-irrigated rice has an expressive share in the gross domestic product, but given the current scenarios it has been suffering a slowdown in cultivation, having as the pivot of the situation the high production costs, where the system of pumping has a direct participation, being through the high cost of implantation of the system, consumption of water and electric energy. The following work has as principles to evaluate the efficiency of pumping systems in an irrigated rice producing property, located in the city of Alegrete-RS. The activities were divided into two stages, in order to characterize the irrigation system, surveying the system data: flow; geometric heights, length of suction and discharge piping; diameter of pipes, characterization of special parts, centrifugal pump and electric motor. The second stage is defined as: verifying the efficiency of the existing pumping systems installed on the property; present its real efficiency; propose a resizing, showing a new scenario in which, it becomes more efficient, with a higher yield and at the same time meeting the water demands of the irrigated rice crop. The work can show the situation found in the field where, in the first pumping station, it was possible to achieve savings of 46.7% in energy consumption after resizing. In the second system evaluated, it was possible to adapt its operation in order to meet the required flow, for this the best scenario was the use of a 640 mm diameter pipe that provided the best hydraulic parameters combined with lower energy consumption.