CN211474319U - A stationary vane device for improving the efficiency of a large flow Francis turbine - Google Patents

Abstract

The utility model discloses a stationary vane device for improving the efficiency of a large-flow Francis turbine, belonging to the field of hydraulic turbine design of a hydroelectric unit. Below the components and above the impeller of the high-head Francis turbine, a water-leakage prevention ring is arranged inside the runner chamber, and a tail water drain pipe is connected below the high-head Francis turbine. The water inlet guide vane of the water turbine is connected with the water turbine governor, and the water turbine governor is used to control the opening of the water inlet guide vane of the water turbine. The utility model makes the water turbine more efficient, improves the water utilization rate, increases the power generation, and improves the economic benefit level of the hydropower station.

Description

A stationary vane device for improving the efficiency of a large flow Francis turbine

technical field

The utility model relates to a stationary vane device for improving the efficiency of a large-flow Francis turbine, belonging to the field of turbine design of a hydroelectric unit.

Background technique

Hydropower is clean energy, renewable, non-polluting, and low in operating costs. Under the circumstance that the earth's traditional energy sources are increasingly tense, countries in the world generally give priority to the development of hydropower and make great use of hydropower resources.

A water turbine is a power machine that converts the energy of water flow into rotating mechanical energy, and it belongs to turbomachinery in fluid machinery. In the hydropower station, the water in the upstream reservoir is led to the turbine through the water diversion pipe, which drives the runner of the turbine to rotate, and drives the generator to generate electricity. The finished water is discharged downstream through the tailpipe. The higher the water head and the greater the flow, the greater the output power of the turbine.

According to the working principle, hydraulic turbines can be divided into two categories: impact turbines and impact turbines. The runner of the impact turbine rotates under the impact of the water flow, and the pressure of the water flow remains unchanged during the working process, which is mainly the conversion of kinetic energy; the runner of the impact turbine rotates under the reaction force of the water flow in the water, and the pressure of the water flow during the working process is Both energy and kinetic energy are changed, but mainly the conversion of pressure energy.

Francis turbine is the most widely used type of turbine in the world. The applicable water head range of Francis turbine is 5 to 700 meters, but the most used is 40 to 300 meters.

Because the axial thrust borne by the lower axial thrust bearing of the turbine cannot be infinite, and due to the limitation of the metal material of the current thrust bearing and the limitation of the sealing conditions of the lower axial thrust bearing of the turbine, the overall power of the designed turbine is currently limited ( The power required by the turbine is large, the water head must be large, the flow through the water must be large, and the thrust bearing of the turbine will bear the thrust.) The thrust bearing of the turbine has become the bottleneck of the design of the turbine.

The equipment of the hydroelectric unit is huge, the structure is complex, and the capacity of the reservoir is limited. When the water turbine generates electricity, when the water flows from the volute to the impeller of the runner chamber, a vortex is formed due to irregular motion, which increases the energy loss, and the water flows from the volute to the runner. In the process of the impeller in the wheel chamber, a part of the impeller directly flows to the tail water drainage pipe from the gap between the impeller and the runner chamber, resulting in a huge waste of energy. Therefore, there is an urgent need for a large-flow Francis turbine. Improve water energy utilization and reduce energy waste.

Utility model content

The purpose of the present utility model is to overcome the above-mentioned deficiencies in the prior art, and to provide a stationary vane device for improving the efficiency of a large-flow Francis turbine.

The technical scheme adopted by the present utility model to solve the above problems is: a stationary vane device for improving the efficiency of a large-flow Francis turbine, including a high-head Francis-turbine, characterized in that an impeller of the high-head Francis-turbine is provided above the impeller. The stationary blade part is provided with a water leakage prevention ring inside the runner chamber below the stationary blade part and above the impeller of the high-head Francis turbine. The water turbine inlet guide vanes are arranged above the water turbine and the stationary blade parts, and the water turbine water inlet guide vanes are connected with the water turbine governor, and the water turbine governor is used to control the opening of the water turbine water inlet guide vanes.

Further, the water turbine governor controls the opening of the water inlet guide vanes of the water turbine through the relay, so as to realize the adjustment of the rotational speed and the load.

Further, the communication cable of the water inlet guide vane of the water turbine is designed with two types of wiring redundancy: soft wiring and hard wiring, which makes the control more reliable.

Compared with the prior art, the utility model has the following advantages and effects: when the hydroelectric unit is running, the high-flow Francis turbine's high-efficiency stationary vane device reduces the eddy current loss between the turbine volute and the impeller, and reduces the amount of water in the water. In the process of flowing from the volute to the impeller of the runner chamber, the loss directly flows from the gap between the impeller and the runner chamber to the draft water drainage pipe, which makes the turbine more efficient, improves the water utilization rate, increases the power generation, and improves the hydropower station. level of economic benefits.

Description of drawings

FIG. 1 is a schematic structural diagram of an embodiment of the present invention.

In the figure: high-head Francis turbine 1, stationary vane part 2, water leakage prevention ring inside the runner chamber 3, tail water drain pipe 4, turbine inlet guide vane 5, and turbine governor 6.

Detailed ways

The present utility model will be further described in detail below with reference to the accompanying drawings and the embodiments. The following embodiments are the explanations of the present utility model and the present utility model is not limited to the following embodiments.

Referring to FIG. 1, the stationary vane device for improving the efficiency of a large-flow Francis turbine in this embodiment includes a high-head Francis turbine 1. A stationary vane part 2 is provided above the impeller of the high-head Francis turbine 1. The stationary vane part 2 Below and above the impeller of the high-head Francis turbine 1 is provided with a water-leakage prevention ring 3 inside the runner chamber, and a tail water drain pipe 4 is connected below the high-head Francis turbine 1. Between the high-head Francis turbine 1 and the stationary vane 2 is provided with a water turbine inlet guide vane 5, which is connected to a water turbine governor 6, and the water turbine governor 6 is used to control the opening of the water turbine inlet guide vane 5.

In this embodiment, the water turbine governor 6 controls the opening of the water inlet guide vanes 5 of the water turbine through the relay, so as to realize the adjustment of the rotational speed and the load.

In this embodiment, the communication cable of the water inlet guide vane 5 of the turbine is designed with two redundant wirings of soft wiring and hard wiring, which makes the control more reliable.

The design method of the stationary vane device to improve the efficiency of the large flow Francis turbine is as follows:

1) Install the stationary blade part 2 above the impeller of the high-head Francis turbine 1 to reduce the eddy current loss between the turbine volute and the impeller;

2) Install a water-leakage prevention ring 3 inside the runner chamber above the impeller of the high-head Francis turbine 1 and below the stationary vane part 2 to reduce the direct flow of water from the volute to the impeller in the runner chamber by the impeller and the runner. The gap between the chambers flows to the loss of the tail water drain 4;

3) The high-head Francis turbine 1 is put into operation, and the turbine governor 6 is opened synchronously to control the turbine inlet guide vanes 5;

4) The water outlet of the lower tail water drain pipe 4 is normal;

5) High head Francis turbine with 1 liter speed;

6) High-head Francis turbine 1 is connected to the grid;

7) High head Francis turbine with 1 liter load to rated.

When the hydroelectric unit is running, the high-flow Francis turbine's high-efficiency stationary vane device reduces the eddy current loss between the turbine volute and the impeller, and reduces the direct flow of water from the volute to the impeller in the runner chamber by the impeller and the impeller. The gap between the runner chambers flows to the loss of the tail water drainage pipe 4, which makes the turbine more efficient, improves the water utilization rate, increases the power generation, and improves the economic benefit level of the hydropower station.

Because P=f(H,Q)

In the formula: P-turbine power;

H - turbine inlet head;

Q - Turbine inlet water flow.

The higher the water head and the greater the flow, the greater the output power of the turbine. The utility model increases the water flow Q at the impeller of the water turbine, and simultaneously reduces the eddy current loss between the volute and the impeller, thereby improving the efficiency of the water turbine.

When the utility model is used in the existing hydropower station, the water head H at the inlet of the turbine is fixed, the water flow Q at the inlet of the turbine increases, so the power P of the turbine is increased, so the electricity is increased, the water energy is saved, and benefits are created for the hydropower station.

Contents not described in detail in this specification belong to the prior art known to those skilled in the art.

Although the present utility model has been disclosed above with examples, it is not intended to limit the protection scope of the present utility model. Any skilled person familiar with the technology can make changes and modifications without departing from the concept and scope of the present utility model. , should belong to the protection scope of the present utility model.

Claims (2)

1. A stationary vane device for improving efficiency of a large-flow Francis turbine, comprising a high-head Francis turbine (1), characterized in that a stationary vane component (2) is provided above the impeller of the high-head Francis turbine (1). ), a water-leakage prevention ring (3) inside the runner chamber is arranged below the stationary vane component (2) and above the impeller of the high-head Francis turbine (1), and the lower part of the high-head Francis turbine (1) is connected with a The tail water drainage pipe (4) is provided with a water turbine inlet guide vane (5) above the high-head Francis turbine (1) and the stationary blade part (2), and the water turbine inlet guide vane (5) is connected with the water turbine regulator The speed regulator (6) is connected, and the water turbine speed regulator (6) is used to control the opening of the water inlet guide vane (5) of the water turbine. 2. The stationary vane device for improving the efficiency of a large-flow Francis turbine according to claim 1, wherein the turbine governor (6) controls the opening of the turbine inlet guide vane (5) through a relay, Realize speed and load regulation.

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