A research team led by Kim Tok Su, head of the Electric Power System Institute, and Mun Yong Guk, a section head at the same institute, has developed a flow meter which measures flow in real time in hydropower plants by using Winter Kennedy method.
Winter-Kennedy method utilizes a static pressure difference between the outside and the inside of a turbine spiral due to the centrifugal force acting on the curved streams of liquid in the spiral case.
The flow calculation formula in the flow meter using Winter Kennedy is Q=khn, where K is a constant coefficient and n is a power exponent which is theoretically equal to 0.5, but could be chosen between 0.48~0.51.
Generally, the values of the constant K can be determined experimentally by using flow Q measured by other standard flow meter. However, they have established a method of determining the coefficient K through FLUENT simulation.
They have introduced and examined the proposed flow meter in a generator. The result was n=0.497 9, K=0.057 and the maximum error compared with a standard flow meter was 0.616%.
As this simulation method is helpful to estimate power exponents and flow coefficients for any spiral cases, the flow meter can be used for all hydro power plants with a spiral case. It is simple in installation and it does not disturb fluid flow. Moreover, real-time measurement is possible with low cost but high accuracy.
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