Central pipe provided with grid mesh and serving as draft pipe of vortex suppression device

Abstract

The invention discloses a mixed flow water turbine central pipe provided with a grid mesh and serving as a draft pipe of a vortex suppression device. The central pipe comprises a right cone cylinder;a cylindrical central pipe is coaxially arranged in the right cone cylinder; six flat plates perpendicularly arranged are connected into the central pipe and are divided into two groups; each group comprises three flat plates; the three flat plates in each group are arranged at intervals in parallel; the three flat plates of the first group are perpendicularly connected with the three flat platesof the second group; the middle flat plate of three flat plates in each group is arranged in the diameter direction of the central pipe; the other two flat plates of three flat plates in each group are positioned on the two sides of the middle flat plate in the same group; the two ends of the six flat plates are fixedly connected with the inner wall of the central pipe; the six flat plates dividethe cavity of the central pipe into a grid mesh structure; and when water flows out of the outlet of a runner and flows into the central pipe, a vortex strip is damaged, the velocity circulation is reduced, and water flow rotation at the center causes negative pressure reduction, so that the strength of the velocity circulation is lowered to weaken pressure pulsation.

Description

technical field [0001] The invention relates to a mixed-flow water turbine in a fluid machine, in particular to a draft pipe part of the mixed-flow water turbine, in particular to a straight-cone draft pipe equipped with a vortex suppression device. Background technique [0002] A water turbine is a power machine that can convert the potential energy of water flow into mechanical energy. It uses water flow as a power to drive other machines to work, and belongs to the turbine machinery in fluid machinery. A water turbine will be provided with a draft tube at the outlet of its runner to collect the water flowing out of the runner and send it to the downstream river channel and recycle the remaining energy of the water flow at the outlet of the runner. When the turbine operates away from the design condition, the velocity at the runner outlet may produce a circumferential component, causing the central pressure inside the draft tube to be low and the surrounding pressure to be...

AI Technical Summary

Problems solved by technology

However, due to the fact that the splitter is close to the inner wall of the draft tube and its unique structure and layout form, the cross-sectional area of ​​the flow is small, the local fluid velocity in the mainstream area becomes low, and backflow is easy to occur

In addition, the design of the built-in shunt plate makes it difficult to disassemble and replace when the shunt plate and the shunt tube are damaged.

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