Investigation of the Pump, Dissipation and Inverse Turbine Operating Modes Using the CATHARE-3 One-Dimensional Rotodynamic Pump Model

Abstract

A predictive transient one-dimensional rotodynamic pump model is currently developed into the CATHARE-3 thermal-hydraulic system code at CEA Saclay, France. Flow is computed in each part of the pump (suction, impeller, diffuser, volute and discharge pipe) based on the definition of a mean stream line. Several cells are used to mesh each part of the rotodynamic pump, which makes this model different from usually called “1D models”. In this study, the model is tested on a medium specific speed centrifugal pump in every operating modes encountered in the first quadrant (positive flow rate and rotational speed). A flow rate evolution is performed at the nominal rotational speed and also at rotational speed equal to zero in order to produce complete first quadrant homologous curves. Relative discrepancy between computation and experiment is respectively less than 10% and 15% on the whole obtained homologous head and torque curves.

Simulation of a Radial Pump Fast Startup and Analysis of the Loop Response Using a Transient 1D Mean Stream Line Based Model

“…Several slip factor correlations have been implemented in the 1D pump model in order to make sensitivity studies and evaluate qualities and defaults of each (those of Stodola [32], Stanitz [33], Wiesner [34] and Qiu [35] as well as the one developed in the frame of this project). These correlations have been tested on four centrifugal pumps, two mixed flow pumps and one radial compressor (Matteo et al [8][9][10][11][12][13]). The correlations are described here after.…”

“…To make the developed pump model general, non-dimensional quantities, such as the specific speed and the rotational speed ratio, have been introduced into the coefficients of the loss models. A limit of the rotational speed ratio ω ω N has been introduced in relation with the work conducted on locked rotor situations (Matteo et al [12,13]).…”

“…The maximal relative error is reached at a very low flow rate close to 30%Q N . The strengths of the model are, first, to ensure such an order of error for very different geometries from radial to mixed flow machines (10 < N q < 120) and from little to very large components (20 cm < D impeller < 150 cm), and, second, to predict these presented performance curves with a very low computation cost (6 s on one core of a standard computer) (see Matteo et al [9][10][11][12][13]). Probabilistic studies can complete such a model by changing randomly parameters of the model and analysing the impact of uncertainties on the final results.…”

“…This traditional model is not predictive and cannot be used for Generation IV two-phase flow applications. For this reason, it was decided to implement a predictive transient, two-phase flow rotodynamic pump model in the CATHARE code and qualify results at component scale (pump) and system scale (reactor) with respect to available experimental data (Matteo et al [8][9][10][11][12][13]). The global strategy of the CATHARE-3 one-dimensional pump model development project and the first pump-scale verification and validation results were presented by Matteo et al [8,9].…”

Transient compressible simulation of a high-speed radial compressor using the CATHARE system code

“…To improve thermal-hydraulic safety and design studies, the thermal-hydraulic simulation section of the French Alternative Energies and Atomic Energy Commission (CEA) has worked on a predictive 1-D pump model in the CATHARE code (see Refs. Matteo et al, 2018Matteo et al, , 2019aMatteo, 2019). A 1-D streamline approach in order to model a turbomachine is rare in the literature, as it lies between the classical input/output 0-D methods and the 2-D through flow and 3-D CFD ones.…”