Desenvolvimento, avaliação técnica e econômica de uma roda d’água flutuante para bombeamento de água.

Abstract

Access to water for irrigation and agricultural activities in remote rural areas often depends on alternative energy solutions, especially in locations without connection to the electric power grid. This study presents the development and experimental investigation of a water pumping system driven by a floating water wheel, designed to operate exclusively through the hydrokinetic energy of a natural watercourse. The system was constructed, installed, and tested along a stretch of the Tormenta River, in the municipality of Catanduvas, in the state of Paraná, Brazil, where measurements of pumped flow rate, manometric head, torque, rotational speed, and current velocity were performed. Based on the experimental data, hydraulic power, mechanical power, and pumping power were determined, as well as the hydraulic, mechanical, and overall efficiencies of the system. The prototype operated continuously, despite the intermittent behavior characteristic of the Wirtz pump, and achieved a maximum hydraulic efficiency of 72%. The maximum mechanical and overall efficiencies were 7.94% and 5.71%, respectively. The pumped flow rates proved to be compatible with the water demands of small family farms. The economic analysis indicated the system’s feasibility, with an implementation cost of R$ 2,500.00. Compared with the avoided cost of conventional water supply, the system presented a discounted payback period shorter than the estimated service life of the equipment and a levelized energy cost of R$ 1.00 per m³ of pumped water. The results demonstrate that floating water wheels constitute a sustainable, low-cost, and technically feasible solution for isolated rural communities.