ENERGY CONSUMPTION AND EFFICIENCY Of WATER PUMPING STATIONS TO IRRIGATE RICE CROP FIELDS

Este trabalho teve como objetivo avaliar o consumo de energia e a eficiência das estações de bombeamento de lavouras de arroz irrigado, na localidade de Arroio Grande, município de Santa Maria, RS. Das 95 estações de bombeamento visitadas, 21 foram avaliadas quanto ao rendimento e consumo de energia. Os resultados evidenciaram que 67% das bombas operavam com rendimentos abaixo de 75%. Houve uma grande amplitude na relação CV ha-1 entre as fontes de potência, variando de 0,93CV ha-1 (conjuntos motobombas elétricos) a 6,30CV ha-1 (acionados por tratores a diesel). Constatou-se que as potências nominais instaladas estavam de 200% a 4250% acima das necessárias e que há desperdício de energia na irrigação de lavouras de arroz. Verificou-se, também que, adequando-se as estações de bombeamento, é possível economizar 29% da energia elétrica com a redução das perdas de carga e 41%, com a redução das perdas de carga e a substituição das atuais motobombas por outras com rendimentos mínimos de 75%.The objective of this work was to evaluate the energy consumption and the efficiency of the water pumping stations to irrigate rice crop fields at Arroio Grande, Santa Maria county, RS, Brazil,. 95 water pumping stations were visited, but only 21 were avaluated considering yield. Results showed that 67% of the water pumping stations were under 75% of it is operational efficiency. The ratio CV ha-1 showed great amplitude between the different power sources. For electrical power stations the ratio was 0.93CV ha-1 and for water pumping systems moved by tractors the ratio was 6,30CV ha-1. It was noticed that all power stations operated between 200% and 4250% over what would be normally necessary to irrigate the rice cultivated area. It was also observed that, under safe conditions electric energy could be saved up to 29% by re-evaluating head losses and, 41% if included a substitution of the current equipments pumping systems, for others minimum efficiency of 75%