Performance of a centrifugal pump running in inverse mode

Abstract

This paper presents the functional characterization of a centrifugal pump used as a turbine. It shows the characteristics of the machine involved at several rotational speeds, comparing the respective flows and heads. In this way, it is possible to observe the influence of the rotational speed on efficiency, as well as obtaining the characteristics at constant head and runaway speed. Also, the forces actuating on the impeller were studied. An uncertainty analysis was made to assess the accuracy of the results. The research results indicate that the turbine characteristics can be predicted to some extent from the pump characteristics, that water flows out of the runner free of swirl flow at the best efficiency point, and that radial stresses are lower than in pump mode

Pumps as turbines for efficient energy recovery in water supply networks

“…Different studies compare the investment costs of PAT's with conventional turbines. Fernandez et al [8] conclude that there is a significant reduction in the investment costs of micro-hydro plants when using pumps instead of turbines. Yang et al [27] summarise that pumps working as turbines (P ¼ 1 to 500 kW) allow payback periods of two years or less, which is considerably less than that of a conventional turbine.…”

Innovative mini-hydro device for the recharge of electric vehicles in urban areas

“…Pumps manufactures, indeed, usually do not provide information about efficiency of a pump used like a turbine. Various researchers indicated the single-stage centrifugal pumps as the optimal and most convenient choice for a PAT, operating, however, in a range from low-to-medium head [12][13][14][15]. However, most of tests and experiments were conducted on horizontal single-stage pumps, although different types of pumps are available like multi-stage, vertical pumps, etc.…”

Analysis on Characteristic of Pressure Fluctuation in Hydraulic Turbine with Guide Vane

“…In general pump-as-turbine is used to recover residual pressure energy of high pressure fluid, and has a high efficiency，so it is applied widely in petrochemical engineering、desalination plant and ferrous metallurgy [1][2][3][4][5][6], etc. But this kind of hydraulic turbine belongs to typical rotary machinery, the operating condition of which is very narrow，and vibration always appears.…”

“…Mechanical vibration is caused by the mechanical design and manufacturing，while electromagnetic vibration is caused by the vibration of motor, currently these two vibrations had been perfectly solved through active control technology [7][8]; Hydraulic vibration is mainly caused by pressure fluctuation in hydraulic turbine，and pressure fluctuation is one of the key factors of affecting the stability of turbine unit , so it is important to analyse the pressure fluctuation for the solution of hydraulic vibration. Several research studies have indicated that the efficiency can be improved and the radial force can be reduced by adding guide vane [9] , but the hydraulic vibration still exists, so the pressure fluctuation for hydraulic turbine with guide vane needs to be studied to further understand the vibration problem. The research for the pressure fluctuation of hydraulic turbine with guide vane is scarce, but the experiences of pressure fluctuation in centrifugal pumps and other hydraulic machineries can be used for reference.…”