Operation Theory of Wind Pumps (2)

Abstract

Following on a preceding paper of the same title [1], and the establishment of the dependence of the wind-pump performance on the wind-pump's Froude number, υ/√ gh, an analytical analysis of the wind-pump's design parameters is further developed in this work. The result was the formulation of the system criteria that continuously match the load with the varying wind speed and water head. This led to a design procedure that entails variation of the pump stroke, the rotational speed-ratio or the turbine's pitch angle to sustain a continuous peak performance. The stroke and speed-ratio variations are such that any of them is continuously proportional to the square of the wind-pump's Froude number. The pitch-angle variation technique requires an inverse relation between the design torque-coefficient and the square of Froude number. The suggested power maximization techniques lead to the continuous operation of the turbine at its maximum power-coefficient point, as long as the operational Froude number is above its stop limit. The arrangements have the implicit advantage of minimizing the start and stop wind speeds of the wind pump.

Optimization of large-scale wind-powered centrifugal pumps

“…This is the central contribution of this study. It trails from previous reported results on the continuous matching of conventional piston pumps and wind turbines (Siddig, 2010a, 2010b). The main outcome of those studies is the establishment of the dimensionless parameter, v /√( gh ), as the single independent parameter that determines the wind pump’s behaviour.…”