Índices de desempenho para estações de bombeamento em lavouras de arroz irrigado

Abstract

The state of Rio Grande do Sul (RS) grown in crop 2013/2014, 1,120,112 ha of rice, making up 46.18% of the cultivated area in Brazil, accounting for 66.21% of national production. The Fronteira Oeste of RS cultivated an area of 333,695 ha and 85.7% of this water pumping stations are used, making the cost of irrigation represents 10.74% of the total cost of production of cereal, one of the most expressive. The efficiency of energy use in the process of irrigation of rice fields linked to this agronomic aspects (definition of cultivars and suitable choice of the area) and engineering (pump of choice with adequate affieciency, adjusted net power engine with the need, compatible coupling with installed capacity, pipe sizing, positioning the pump-motor assembly and use of special parts). The lack of parameters that can define the quality of the design of pumping stations creates uncertainty regarding the proper use of energy in the process. Performance indices are indicators that can be used to establish the quality of pumping stations, with regard to aspects sizing. This work aimed to propose performance indexes and ranks them in order to generate referrals, to be used for evaluation of water pumping stations in irrigated rice fields. We evaluated 160 pumping stations, located on the Western Border of RS, under normal working conditions. For each of them were determined appropriate piping, through total cost minimization analysis (fixed more operational) for a period of 10 years of operation, and checked the possible power savings from the same exchange. Similarly been proposed replacement of equipment (pumps and motors) seeking, among commercially available, those with higher operating efficiency for the working conditions of each season. Were proposed nine performance indices and applied situations initially found in the field and those optimized by the replacement of pipes, pumps and motors. The variability found allowed them to be categorized and then was proposed performance index rating as "excellent", "very good", "good", "bad" and "very bad".