Simultaneous efficiency improvement of pump and turbine modes for a counter-rotating type pump-turbine

Abstract

This article presents a multi-objective optimization to improve the hydrodynamic performance of a counter-rotating type pump-turbine operated in pump and turbine modes. The hub and tip blade angles of impellers/runners with four blades, which were extracted through a sensitivity test, were optimized using a hybrid multi-objective genetic algorithm with a surrogate model based on Latin hypercube sampling. Three-dimensional steady incompressible Reynolds-averaged Navier-Stokes equations with the shear stress transport turbulence model were discretized via finite volume approximations and solved on a hexahedral grid to analyze the flow in the pump-turbine domain. For the major hydrodynamic performance parameters, the pump and turbine efficiencies were selected as the objective functions. Global Pareto-optimal solutions were searched using the response surface approximation surrogate model with the non-dominated sorting genetic algorithm, which is a multi-objective genetic algorithm. The trade-off between the two objective functions was determined and described with regard to the Pareto-optimal solutions. As a result, the pump and turbine efficiencies for the arbitrarily selected optimum designs in the Pareto-optimal solutions were increased as compared with the reference design.

Effect of space diffuser on flow characteristics of a centrifugal pump by computational fluid dynamic analysis

“…The boundary conditions, solver governing equations, and post processing of the results were performed using ANSYS CFX and CFD-Post, respectively [3]. The inlet total pressure and the outlet mass flow rate were set as the inlet/outlet boundary conditions.…”

“…The pressure loading (p + -p -: the pressure difference across the blade) is calculated through the following equation for incompressible flows. As shown in Eq (13), the blade pressure loading is directly proportional to distribution of @(rV θ )/@m. And, the local Euler head is defined as the product of the local peripheral speed and the circumferential component of absolute velocity divided by the gravity acceleration (given in Eq (14)) [3], which has the same distribution with the expression of rV θ . Thus, the distribution of the local Euler head along the meridional direction could be adopted to describe the blade loading.…”

“…Most of these works focus on the core component of the pump, e.g. the impeller [3][4]. Influences of various structural parameters of the impeller on flow characteristics of the pump are studied, including the blade angle, the wrap angle, the impeller diameter, the inlet/outlet width, the blade fillet, and so on.…”

Comprehensive Review of Pump as Turbine

“…Multi-objective optimization to improve the hydrodynamic performance of a counter-rotating type pump-turbine operated in pump and turbine modes was illustrated [43]. The inlet and outlet blade angles of impellers/runners with four blades, which were extracted through a sensitivity test, were optimized using a hybrid multi-objective genetic algorithm with a surrogate model based on Latin hypercube sampling.…”

Feasibility Analysis of Existing Compressor Design for Different Refrigerants

“…Consequently, this model was used for subsequent simulations. The use of k- SST model gives reasonably accurate results for CFD analysis of fluid machinery [14][15][16][17][18]. An intercooler exits between the first and the second stage.…”