Method for calculating parabolic wake flow model of wind power unit by influence of considering turbulence intensity

Abstract

The invention belongs to the technical field of microcosmic location selection of a wind power plant, and particularly relates to a method for calculating a parabolic wake flow model of a wind power unit by considering influence of turbulence intensity. The method comprises the following steps of S1, assuming that the radius of a wake flow region is linearly increased and the radius of a wake flow region close to the back part of a wind wheel is the same as that of the wind wheel, and calculating the radius r of a wake flow region in the position of a back axial distance x of the wind wheel; S2, assuming that a wind velocity in the position of the back axial distance x of the wind wheel is uniformly distributed in a radial direction, and obtaining a uniform wind velocity v* according to mass conservation; S3, according to the mass conservation and the uniform wind velocity v*, obtaining a wind velocity v of any point on a horizontal plane of the height of a hub; S4, considering an influence of the turbulence intensity of the wake flow region on a wake flow recovery coefficient k, and by referring to an empirical formula for calculating additional turbulence intensity of blade rotation, obtaining a calculation formula of the wake flow recovery coefficient k; and S5, substituting the wake flow recovery coefficient k into the calculation formula of the window velocity v, thereby obtaining an empirical wake flow model of wind velocity distribution of the wake flow region of the wind power unit.

Description

technical field [0001] The invention belongs to the technical field of micro-site selection of wind farms, and in particular relates to a calculation method for a parabolic wind turbine wake model considering the influence of turbulence intensity. Background technique [0002] The problem of energy shortage and environmental pollution is becoming more and more serious, and wind energy, as a renewable clean energy, is being used more and more. As onshore and offshore wind farms are gradually built and put into operation, many problems follow. Among them, the problem that the power generation of downstream wind turbines is affected by the wake effect of upstream wind turbines is extremely prominent. The wake effect of wind turbines mainly leads to the reduction of wind speed in the wake area, resulting in the loss of power generation of wind turbines in the wake area. Both the micro-site selection of wind farms and the power prediction of wind farms need to consider the influ...

AI Technical Summary

Problems solved by technology

The empirical wake models used by commercial software mainly include Jensen, Larsen, and Ainslie models, etc. Among them, the Jensen model has the simplest structure, and the assumption that the wind speed in the wake area is uniformly distributed along the radial direction is quite different from the actual situation, and the environmental turbulence intensity is not considered. The impact on wake recovery underestimates the recovery of wind speed in the wake area; the Larsen model assumes that the wind speed is Gaussian in the radial direction, but overestimates the recovery of wind speed, especially in the near wake area; the Ainslie model uses vortex The swirl viscosity theory solves the N-S equation to obtain the wind speed distribution in the wake area, which has high calculation accuracy but long calculation time

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