CN218376708U - Water diversion power generation system combining high-head mixed-flow type water turbine and impulse type water turbine - Google Patents

Abstract

The utility model provides a water diversion power generation system combined with a high head mixed flow type and an impact turbine. The water diversion power generation system is arranged between an upstream reservoir and a downstream river channel. The water diversion power generation system includes a water diversion tunnel and a pressure pipe connected in sequence And the water turbine unit, one end of the diversion tunnel communicates with the upstream reservoir, the other end communicates with the pressure pipe, the water turbine unit communicates with the downstream channel, the pressure pipes are arranged in parallel, and each pressure pipe communicates with a water turbine unit, The plurality of hydraulic turbine sets include at least one impulse hydraulic turbine set and one Francis hydraulic turbine set, and a valve is arranged between the pressure pipe and the hydraulic turbine set. The water diversion power generation system can save equipment costs, reduce construction difficulty, and improve system safety.

Description

A Water Diversion Power Generation System Combining High Head Francis Type and Pelton Turbine

technical field

The utility model relates to the field of water conservancy power generation, in particular to a water diversion power generation system combined with a high water head mixed flow type and an impact type water turbine.

Background technique

In the process of designing the water diversion power generation system of a hydropower station, it is necessary to consider the convenience of unit scheduling and operation and maintenance management. Usually, the same type of turbines should be installed in the powerhouse of a hydropower station. For hydropower stations with a water head higher than 300m, the optional turbine types include impulse turbines and Francis turbines. Among them, the impact turbine is suitable for high head and small flow hydropower stations, while for high head and large flow hydropower stations, Francis turbines are usually used. Francis turbines have the characteristics of compact structure, high efficiency, etc., and are subjected to high head pressure.

During the working process of the power grid, grid disassembly may occur. Grid disassembly means that the power system is disturbed, its stability is destroyed, and there is a loss of When the synchronization cannot be restored, it is necessary to cut off the electrical connection between them and decompose them into mutually independent and unconnected parts, so as to prevent the accident from expanding and causing serious consequences. When the power grid breaks down, the Pelton Turbine or Francis Turbine needs to perform load shedding. During the load shedding process of the unit accident, the Pelton Turbine can quickly switch the direction of the deflector and then slowly close the nozzle to effectively curb the increase in the speed of the unit. rate and control the pressure of the water distribution ring pipe at the same time; in the process of unit accident load shedding, in order to limit the pressure increase of the volute of the turbine, the guide vane usually closes for a long time, resulting in a high rate of increase in the speed of the unit, and the unit has flying The risk of escape, and the vibration is relatively large, which has an adverse effect on the structural stability of the plant.

In order to solve various problems caused by the selection of high-head Francis turbines, according to the traditional design method, it is usually used to increase the moment of inertia of the generating set, accelerate the closing speed of the guide vane and increase the area of the surge chamber to simultaneously control the speed increase rate of the unit and the volute. Increase the value of the pressure to meet the safety of the water diversion power generation system. However, increasing the moment of inertia of the unit and increasing the area of the surge chamber not only increases the manufacturing cost of the unit, but also increases the difficulty of construction.

Utility model content

The purpose of the utility model is to provide a water diversion power generation system combined with a high head mixed flow type and an impact turbine. The water diversion power generation system can save equipment costs, reduce construction difficulty, and improve system safety.

In order to achieve the above purpose, the utility model provides the following technical proposal: a water diversion power generation system combined with high head mixed flow type and impact turbine, the water diversion power generation system is set between the upstream reservoir and the downstream river channel, and it is characterized in that the The water diversion power generation system includes a water diversion tunnel, a pressure pipe, and a water turbine set connected in sequence. One end of the water diversion tunnel is connected to the upstream reservoir, and the other end is connected to the pressure pipe. The water turbine set is connected to the downstream river. The pressure pipes are arranged in parallel. Each pressure pipe communicates with a hydraulic turbine set, and the multiple hydraulic turbine sets include at least one impulse hydraulic turbine set and one Francis hydraulic turbine set, and a valve is arranged between the pressure pipe and the hydraulic turbine set.

Further, the water head of the impulse turbine set and the Francis turbine set is not lower than 300m.

Further, the impulse turbine unit is connected with the downstream channel through the tailrace, and the Francis turbine unit is communicated with the downstream channel through the draft tube.

Further, the valve is arranged at the end of the pressure pipe.

Further, a main valve is arranged between the diversion tunnel and the pressure pipe.

Further, a surge shaft is provided between the diversion tunnel and the main valve.

Further, there are four pressure pipes.

Further, there is one impulse turbine set, and three Francis turbine sets.

The beneficial effects of the utility model:

1. The utility model uses the impact type turbine unit and the mixed flow turbine unit in combination, so that when an accident occurs and the load is shed, the impact type turbine unit can be used to release the pressure, and the mixed flow turbine unit is directly closed, reducing the worm of the Francis turbine unit. The increase rate of shell pressure and speed prevents the risk of runaway of the Francis turbine unit, reduces the vibration of the Francis turbine unit, avoids adverse effects on the stability of the plant structure, and improves the safety of the water diversion power generation system.

2. The utility model combines the impact type water turbine unit and the mixed flow water turbine unit. The water turbine unit solves the problems of the speed increase rate and the pressure of the volute when the load is shed in an accident, and there is no need to increase the moment of inertia of the water turbine unit or increase the pressure regulation well, saving the equipment cost of the turbine unit, and at the same time, the excavated area of the surge well and the powerhouse can be greatly reduced, saving engineering investment and reducing construction difficulty.

3. The utility model can adapt to a wide water head range and a hydropower station with a relatively large flow through the combined use of the impact type water turbine set and the mixed flow water turbine set, and has high efficiency.

Description of drawings

Fig. 1 is the structural representation of the utility model;

Reference signs: upstream reservoir 1, diversion tunnel 2, surge well 3, main valve 4, first pressure pipe 5, second pressure pipe 6, first valve 7, second valve 8, impact turbine unit 9, mixed flow Type water turbine unit 10, downstream channel 11.

Detailed ways

The utility model will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

As shown in the figure, a water diversion power generation system combining high-head Francis and impact turbines is arranged between an upstream reservoir 1 and a downstream river channel 11 .

The water diversion power generation system includes a diversion tunnel 2, a pressure pipe, and a water turbine unit connected in sequence.

The diversion tunnel 2 is provided with a set, one end of which communicates with the upstream reservoir 1, and the other end communicates with the pressure pipe. A main valve 4 is arranged between the diversion tunnel 2 and the pressure pipe. Between the diversion tunnel 2 and the main valve 4 A surge well 3 is arranged between them for adjusting the water pressure in the pressure pipe.

There are multiple pressure pipes arranged in parallel. In this embodiment, there are four pressure pipes, including a first pressure pipe 5 and a second pressure pipe 6. Each pressure pipe is connected to a water turbine unit. In this embodiment Wherein, the pressure pipe is a steel pipe.

The plurality of hydraulic turbines includes at least one impulse hydraulic turbine 9 and one Francis hydraulic turbine 10. In this embodiment, one impulse hydraulic turbine 9 is provided, and the Francis hydraulic turbine 10 is provided with three The impact turbine unit 9 communicates with the downstream channel 11 through a tailrace, and the Francis turbine unit 10 communicates with the downstream channel 11 through a draft tube. The water heads of the impact turbine unit 9 and the Francis turbine unit 10 are not lower than 300m. The impact type water turbine set 9 and the Francis water turbine set 10 are all arranged in the same factory building.

The first pressure pipe 5 communicates with the impulse turbine unit 9 , and the second pressure pipe 6 communicates with the mixed flow turbine unit 10 .

A valve is arranged between the pressure pipe and the water turbine, the ends of the first pressure pipe 5 and the second pressure pipe 6 are respectively provided with a first valve 7 and a second valve 8, and the first valve 7 and the second valve 8 are ball valves.

The usage method of the utility model: when the water diversion power generation system is in normal operation, the main valve 4, the first valve 7, and the second valve 8 are all opened, the impact water turbine unit 9 and the mixed flow water turbine unit 10 work normally, and the water flows from the upstream reservoir 1 It enters each pressure pipe through the diversion tunnel 2 , the surge shaft 3 and the main valve 4 , and then passes through the impact turbine unit 9 and the Francis turbine unit 10 to generate electricity, and finally enters the downstream river channel 11 . When load shedding occurs due to an accident in all units of the power station, the guide vanes of all Francis turbine units 10 adopt a one-stage closing rule and are directly closed, while the deflectors of the impact turbine unit 9 quickly switch directions. Nozzles are not closed, keep open, and play the role of pressure relief. The deflection device prevents the water flow from the nozzles from rushing towards the blades of the impact turbine unit 9, so that the blades of the impact turbine unit 9 stop rotating, thereby reducing the For the volute pressure of the Francis turbine unit 10, after the guide vanes of the Francis turbine unit 10 are completely closed, the nozzles of the impact turbine unit 9 are slowly closed.

The basic principles and main structural features of the present utility model have been shown and described above. The utility model is not limited by the above-mentioned examples. On the premise of not departing from the spirit and scope of the utility model, the utility model also has various changes and improvements, and these changes and improvements all fall into the scope of the utility model claimed. Inside. The scope of protection required by the utility model is defined by the appended claims and their equivalents.

Claims (8)

1. The utility model provides a diversion power generation system that high-water head mixed-flow and impulse turbine made up mutually, diversion power generation system sets up between upstream reservoir (1) and low reaches river course (11), a serial communication port, diversion power generation system is including diversion tunnel (2), pressure pipe and the hydraulic turbine group that communicates in proper order, diversion tunnel (2) one end and upper reaches reservoir (1) intercommunication, the other end and pressure pipe intercommunication, hydraulic turbine group and low reaches river course (11) intercommunication, the pressure pipe is parallelly connected to be set up many, and every pressure pipe and a hydraulic turbine group intercommunication are a plurality of include an impulse turbine group (9) and a hydraulic turbine group (10) in the hydraulic turbine group at least, be provided with the valve between pressure pipe and the hydraulic turbine group.

2. The combined high head francis and impulse turbine diversion power generation system of claim 1, wherein the head of the impulse turbine set (9) and the francis turbine set (10) is not lower than 300m.

3. A high head francis and francis turbine combined hydroelectric power generation system as claimed in claim 1, wherein the francis turbine (9) is connected to the downstream waterway (11) via a tailrace, and the francis turbine (10) is connected to the downstream waterway (11) via a tailrace.

4. A combined high head francis and impulse turbine diversion power generation system as claimed in claim 1, wherein the valve is located at the end of the penstock.

5. A high head francis and impulse turbine combined diversion power generation system as claimed in claim 1, wherein a main valve (4) is provided between the diversion tunnel (2) and the penstock.

6. A high head francis and impulse turbine combined water diversion power generation system according to claim 5, characterized in that a surge shaft (3) is arranged between the diversion tunnel (2) and the main valve (4).

7. A combined high head francis and impulse turbine hydroelectric power generation system as claimed in any of claims 1 to 6, in which four of said penstocks are provided.

8. The combined high head francis and impulse turbine diversion power generation system of claim 7, wherein there are one impulse turbine set (9) and three francis turbine sets (10).

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