Avaliação do consumo energético no controle de vazão em sistema de bombeamento utilizando válvulas mecânicas e inversores de frequência : experiências laboratoriais e estudo de caso

Abstract

This paper presents a system analysis method of pumping with turbopumps to be applied in systems already installed which can be put into operation. It is a practical way to determine the manometric height, the yield of the piping system, of the pump and of the pumping system and the active energy consumption, per cubic meter of pumped fluid, at the point of the system operation. The yield determination of the system components at the operating point allows knowing where to act to achieve a better result in the reduction of energy consumption. The analysis is done by measuring the active power demanded by the pump engine and the flow provided by the system, at the operation point to be analyzed. Besides the described measurements, in order to analyze the system with this method, it is necessary to have the engine yield, the geometric height of the system, the specific weight of the pumped fluid and the pump’s characteristic curve, manometric height in relation to the flow. This pump’s curve should be for the same fluid that is being pumped in the system. In this study, it is shown how the manometric height of a pumping system through the use of tools which measures pressures is determined. This method of manometric height determination allows for the construction of the pump’s characteristic curve, which was cited, to the fluid that is being pumped. The methods of flow control, through a valve and a pump’s rotation, are also analyzed. In order to vary the pump’s rotation the frequency converter in the engine’s drive is used. Two three-phase frequency converters are tested, one with a three-phase supply and another with a single-phase supply. To check the impacts caused by the harmonics in the electric energy quality, the harmonic content generated with the use of the converters is measured and analyzed.