Water turbine draft tube with vortex restraining function

Abstract

The invention relates to a draft tube with the vortex restraining function, and belongs to the technical field of water turbines. The draft tube comprises a draft tube inlet, an upper conical section, a middle conical section, a lower conical section, an elbow tube section, a draft tube outlet and at least one vortex restraining device, wherein the vortex restraining devices are arranged on the inner wall face of the middle conical section, preferably, the number of the vortex restraining devices ranges from two to six, and the upper conical section, the middle conical section and the lower conical section are coaxial. All the vortex restraining devices are of a half-splitting structure and are evenly distributed in the circumferential direction, and the shape, along the axis vertical section, of the half-splitting structure is trapezoidal. The vortex restraining devices are not prone to being damaged by actions of water flow and small in occupied space, does not affect hydraulic performance of a water turbine under other working conditions while restraining vortex actions under the partial load working condition of the water turbine, and can obviously restrain movement of the water flow in the circumferential direction and relieve hydraulic pressure pulses of the water turbine, so that operation stability of the water turbine is improved, the safe operation range of the water turbine is widened, and the working condition adjusting capacity is improved.

Description

technical field [0001] The invention relates to a hydraulic turbine draft tube, in particular to a hydraulic turbine draft tube with a vortex suppression function, which is suitable for improving the internal flow of the draft tube when the hydraulic turbine of a hydropower station operates in a deviation from the design working condition. Background technique [0002] The vortex of the draft tube of the turbine is a special form of vortex, especially in the partial load condition (referring to the condition in which the operating flow of the turbine is less than the design flow), it will cause severe water pressure fluctuations, which seriously affects the safe operation of the hydropower unit. In order to alleviate the pressure pulsation caused by the vortex flow in the draft tube of the hydraulic turbine, a series of measures have been taken in engineering; these measures mainly include the following three aspects: 1) by changing the design of the runner of the hydraulic t...

AI Technical Summary

Problems solved by technology

[0002] The vortex of the draft pipe of the turbine is a special vortex form, especially in the partial load condition (referring to the condition in which the operating flow of the turbine is less than the design flow), it will cause severe water pressure fluctuations, which seriously affects the safe operation of the hydropower unit.

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