Contributions to the determination of the equation for the quivalent head characteristic of a hydraulic generator battery

Abstract

Pumping stations that serve the pressurized and/or free level hydrotechnical systems are equipped, mainly, with several pumping sets, the turbopump (TP) – electric motor. TP have the role of hydraulic generators and present, in general, a parallel connection within the core of basic technological lines (LTB) of the pumping station. In the composition of a LTB there are suction and discharge lines of the TP, and the discharge pipeline (for example, a discharge collector). In order to satisfy in optimal conditions the variable flow requirements and pressure of the hydrotechnic system, a LTB can be equipped with TP of the same type or different types, and some TPs can be adjustable ( with the positions of the stator blades and/or rotor blades that are variable, with the position given by the the angles s and/or r) or adjustable (at the variable turation n). The energetic active TP assembly on a LTB, together with the communication of suction and discharge, assemble a battery of hydraulic generators (BGH); the notion of BGH permits us the equalization, from a functional point of view of the respective assembly with an unique TP. The equivalent charge characteristic of the BGH (CSEBGH) relays the dependence between the pumping load relative to the discharge collector section, HBGH and the total flow rate delivered to the discharge pipeline, QBGH. CSEBGH is useful in the analysis of the cooperation of BGH with the pipeline network of the served hydrotechnic system – the absolutely necessary analysis in the automation of the pumping stations through the SCADA system. In specialty literaturem the analytic expression for CSEBGH was determined only through its explicit form, usual for CS of a TP, HBGH=fH(QBGH), a form which is fossible only for some particular cases of BGH compoistion. In the current paper, for CSEBGH it is proposed a new analytic expression, trough the form forma QBGH=fQ(HBGH), which, by being available for every scenario of the composition of BGH, it presents the generality advantage. Also, for both forms of analytical expression exposed abovem there are presented representative numerical examples