Short tube gas replenishing device for draft tube of water turbine

Abstract

The invention relates to a short tube gas replenishing device for a draft tube of a water turbine, belonging to the field of gas replenishing of a water turbine generator set. The short tube gas replenishing device for the draft tube of the water turbine is characterized in that the short tube gas replenishing device is arranged in the draft tube, passes through the tube wall of the draft tube through four branch tubes and is communicated with the atmosphere through an annular tube to form a gas replenishing loop; four short tubes are uniformly distributed on the same horizontal plane of the draft tube; and each short tube is in an upward arched form, i.e. each short tube forms an angle of 30-45 degrees with the upward horizontal plane or is parallel with the horizontal plane, each short tube is sealed by a plug, a gas outlet hole is formed below each short tube, and each gas outlet hole is positioned in the third quadrant of the cross section of each short tube seen from the center of the draft tube. The short tube gas replenishing device operates stably, and the gas replenishing quantity meets the requirement of the set. The short tube gas replenishing device does not generate the pipeline falling phenomenon, thereby reducing the daily maintenance, lowering the maintenance cost, avoiding the condition that the set operates without the gas replenishing device, and improving the safety and the stability of operation of the set.

Description

technical field [0001] The device belongs to the field of gas replenishment for hydroelectric generator sets. Background technique [0002] There are two types of air supply devices for hydro-generator sets: natural air supply and forced air supply, and the air supply of the short draft tube is natural air supply; 1) For hydraulic turbines, most of the air supply is used to reduce pressure fluctuations . Air supply in the draft tube is used to reduce the vortex pressure pulsation in the draft tube when the Francis turbine operates at partial load, and at the same time increase the internal pressure of the draft tube to improve the cavitation degree of the unit, which is also the main purpose of this project and target. 2) Location: Inside the draft tube of the turbine. [0003] The current air supply method for the draft tube is: the cross air supply frame for the draft tube. [0004] There are mainly two possible reasons for the damage of the air supply rack: one is ins...

AI Technical Summary

Problems solved by technology

[0014] Problems existing in the original technology: The turbine was originally designed and installed with a draft pipe cross air supply rack device, but soon after it was put into operation, the air supply rack was washed away.

According to on-site measurement, in the absence of an air supply rack, the maximum air intake wind speed under various powers is less than 1m / s, and it is in a pulsating air intake state, so the actual air supply volume is very small, and the air supply effect is not ideal; 2) The problems to be solved by the new technology: A. Solve the problem that the original cross gas supply device often falls off; B. Solve the problem of insufficient gas supply in the draft pipe, increase the gas supply volume, and improve the gas supply effect; thereby reducing other pressure pulsations other than the pressure pulsation of the vortex belt ; Reduce the flow noise in the draft tube; increase the pressure in the draft tube to reduce the cavitation of the turbine; slightly increase the efficiency of the turbine in the vortex working area

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