Comparative evaluation of the pump mode and turbine mode performance of a large vaned-voluted centrifugal pump

Abstract

Large vaned-voluted centrifugal pump is a general machine used for large-scale water diversion. As a vane-type hydraulic machinery, it also has the ability of reversible operation. With the introduction of policies to reduce carbon emissions, the proportion of unstable new energy use has increased. The existing large centrifugal pump unit can realize the function of reverse power transfer. For peak shaving and valley filling of power grid, it has high feasibility and economy. In this paper, a large vaned-voluted centrifugal pump is simulated numerically, it is external characteristics and flow state under positive and negative rotation are obtained, its performance is predicted by best efficiency point method, and it is found that pump reversal can run at the optimum efficiency point with higher flow rate and head. Error analysis is carried out for different formulas. The flow energy dissipation (FED) of different flow rates under positive and negative rotation is analyzed. It is found that the main energy loss locates on suction side of blade, inlet and outlet part of blade and tail part of guide blade head. By comparing the flow energy dissipation distribution under the same flow conditions with positive and reverse rotation, it is found that the high energy loss area of blade mainly exists in inlet and outlet part of blade in pump mode. The high energy loss area of the blades in turbine mode mainly exists in the inlet part of the blades. This study is of great significance to the operation of low-carbon power grid assisted by existing reservoirs and hydraulic machinery.

Selection and Performance Prediction of a Pump as a Turbine for Power Generation Applications

“…These correlation coefficients validate the practicality of the proposed correlations within the specified range of hydraulic data. 20) and (21). The deviation between the two techniques varies across different sites.…”

“…Considering the small deviations and the high accuracy of the proposed methodology, it can be concluded that the derived correlations provide a practical and reliable means of estimating the pump flow rate and head based on the available site hydraulic data. 20) and (21). The deviation between the two techniques varies across different sites.…”

“…The overall accuracy of the proposed methodology is within the range of ±3.3% for the pressure head and −0.2% to +1.5% for the flow rate. 20) and (21). The deviation between the two techniques varies across different sites.…”

“…Equation (20) represents the relationship between the site flow rate (QS) and the pump flow rate (QP), indicating that the pump flow rate is approximately 82.5% of the site flow rate. Equation (21) represents the relationship between the site head (HS) and the pump head (HP), indicating that the pump pressure head is approximately 60.5% of the site pressure head.…”

“…Several research works have extensively investigated the performance prediction of pumps operating as a turbine [21]. However, the challenge of pump selection, which is a significant aspect in this field, has not been widely addressed.…”