Flow regulation through a butterfly valve in a cross-flow hydraulic turbine

Abstract

This paper presents the results of research on the flow regulation in a cross flow turbine. Based on the development carried out in this laboratory, a small hydro generator, we worked on some of the most important aspects of the turbine: the flow regulation. The work program was developed in order to quantify experimentally and numerically the influence on the efficiency of the turbine, by using a butterfly valve in the primary regulation of the inflow. The machine used is a cross-flow turbine with a diameter of 200 mm that was coupled upstream with a 6 inches diameter Waffer type butterfly valve. Another goal was to study how these results can be used in the design of electronic control equipment that works under the referral system loads. The work routine consisted in making the regulation of the flow enter the turbine by operating the valve. From this its reveals the various resulting parameters, and once process the data, were compared with results of an unregulated turbine and a conventional controller. As a result we can mention the same behavior of this valve as primary regulator, acceptable and, given the range of powers that are working, we can infer that the same if it is docked at a point in the circuit to allow a good adaptation of streamlines the entry of the nozzle, has practically no influence on the overall performance of the turbine. Therefore we can say that for a "primary control" of the flow, it is achievable to use these standards and elements of features available on the market.