Graded pressure reduction drainage structure of high-water-head power station water diversion system

Abstract

The utility model provides a high-water-head power station water diversion system grading pressure reduction drainage structure which comprises an upper adit construction adit, a middle adit construction adit, a lower adit construction adit and an upper reservoir hoist room, and drainage pipelines are sequentially communicated among the upper adit construction adit, the middle adit construction adit, the lower adit construction adit and a plant. A first throttling orifice plate is arranged on the drainage pipeline between the upper adit construction adit and the middle adit construction adit, and a second throttling orifice plate is arranged on the drainage pipeline between the middle adit construction adit and the lower adit construction adit; a first working ball valve, a second working ball valve and a third working ball valve are arranged on the drainage pipeline on one side of the upper adit construction adit, the middle adit construction adit and the lower adit construction adit respectively, and the pressure difference formed by drainage pressure reduction of each stage is small through segmented drainage in the upper adit construction adit, the middle adit construction adit and the underground main power house. And serious accidents such as large cavitation on a pressure reducing valve and a throttling hole caused by high pressure difference, even pipe explosion of a drainage system and the like are avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of luggage boxes, in particular to a graded pressure-reducing and drainage structure of a water diversion system of a high-head power station. Background Art

[0002] For hydropower stations with long, high-head diversion systems, draining the diversion tunnels after initial water filling tests or after years of operation is necessary to facilitate access for maintenance personnel. Long diversion power stations discharge large volumes and high pressures. If the diversion system were to be fully filled and discharged from the bottom, the high head could potentially impact downstream facilities. Currently, no valves exist that can achieve this pressure reduction over several hundred meters, making damage very likely.

[0003] Conventional drainage schemes for water diversion systems generally include the following: (1) Installing a disc valve at the low point of the volute to discharge the water in the water diversion system to the downstream tailwater pipe. (2) Discharging the water in the water diversion system to the downstream tailwater pipe through the technical water supply system pipeline. (3) Building a dedicated maintenance drainage tunnel for the water diversion system, discharging most of the water, and then discharging the remaining water to the downstream tailwater pipe through the drainage valve installed at the end of the pressure steel pipe. (4) Draining water through the machine. During the start-up or shutdown of the unit, it works in conjunction with the upstream fast working gate. When the turbine generator unit is idling, the water in the water diversion system is directly discharged to the downstream tailwater pipe through the guide vanes and impeller. The above methods are only applicable to power stations with short water diversion systems and low water heads. They have obvious defects for power stations with longer water diversion systems. For example, the use of disc valves in high-head power stations may cause severe vibration and cavitation, and even valve stem breakage. In addition, the drainage and pressure reducing system makes full use of the kinetic energy of water to drive the turbine to generate electricity, ensuring that water can be released at an appropriate speed and pressure. The design needs to consider the impact of the high-speed movement of water on the equipment, including the design and selection of equipment such as turbines, water pipes, and valves, to ensure that the system can operate safely and reliably under high head and large flow conditions. Utility Model Content

[0004] The purpose of this utility model is to overcome the deficiencies of the above-mentioned prior art and provide a graded pressure-reducing drainage structure for a high-head power station water diversion system, which can solve the problem that the large drainage volume of a high-head and long water diversion system may cause impact on downstream facilities.

[0005] To this end, the utility model adopts the following technical solutions:

[0006] A graded pressure-reducing drainage structure for a water diversion system of a high-head power station is arranged between an upstream upper reservoir opening and closing machine room and a downstream main powerhouse, and comprises an upper flat tunnel construction branch tunnel, a middle flat tunnel construction branch tunnel, and a lower flat tunnel construction branch tunnel. Drainage pipes are sequentially connected between the upper reservoir opening and closing machine room, the upper flat tunnel construction branch tunnel, the middle flat tunnel construction branch tunnel, the lower flat tunnel construction branch tunnel, and the powerhouse. A first throttling orifice plate is provided on the drainage pipe between the upper flat tunnel construction branch tunnel and the middle flat tunnel construction branch tunnel, a second throttling orifice plate is provided on the drainage pipe between the middle flat tunnel construction branch tunnel and the lower flat tunnel construction branch tunnel, and a first working ball valve, a second working ball valve, and a third working ball valve are respectively provided on the drainage pipes on one side of the upper flat tunnel construction branch tunnel, the middle flat tunnel construction branch tunnel, and the lower flat tunnel construction branch tunnel.

[0007] On the basis of adopting the above technical solutions, the present invention may also adopt the following further technical solutions, or use these further technical solutions in combination:

[0008] A first maintenance pipe is provided on the drainage pipe on one side of the upper flat tunnel construction branch tunnel, and a first maintenance butterfly valve is provided on the first maintenance pipe.

[0009] A second inspection pipe is provided on the drainage pipe on one side of the Zhongping tunnel construction branch tunnel, and a second inspection butterfly valve is provided on the second inspection pipe.

[0010] Compared with the prior art, the utility model has the following advantages and beneficial effects: the segmented drainage in the upper flat tunnel construction branch tunnel, the middle flat tunnel construction branch tunnel and the underground main powerhouse makes the pressure difference formed by the drainage pressure reduction at each level smaller, avoiding the high pressure difference from causing large cavitation on the pressure reducing valve and the throttle hole, and even causing serious accidents such as pipe burst in the drainage system, and at the same time avoiding the damage to downstream facilities caused by the discharge of all the filling and drainage of the water diversion system of the high head pumped storage power station from the bottom, thereby improving the stability and reliability of the valve; by arranging the first inspection pipeline, the first inspection butterfly valve, the second inspection pipeline, and the second inspection butterfly valve, problems arising from the upper flat tunnel construction branch tunnel, the middle flat tunnel construction branch tunnel and the lower flat tunnel construction branch tunnel can be solved in a targeted manner, narrowing the search scope, saving time and improving efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a system layout diagram of a hierarchical pressure-reducing and drainage structure for a high-head power station water diversion system according to the utility model. DETAILED DESCRIPTION

[0012] In order to enable those skilled in the art to better understand the technical solution of the present invention, the preferred implementation scheme of the present invention is described below in conjunction with specific embodiments. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar numbers throughout represent elements with the same or similar functions. However, it should be understood that the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. In order to better illustrate the present embodiment, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted, and the positional relationship described in the drawings is only used for illustrative purposes and cannot be understood as limiting the present invention.

[0013] The present invention will be further described below with reference to the accompanying drawings and embodiments, but they are not intended to limit the present invention.

[0014] The utility model provides a graded pressure-reducing drainage structure for a water diversion system of a high-head power station, which is arranged between an upper reservoir opening and closing machine room upstream and a main powerhouse downstream, and comprises an upper flat tunnel construction branch hole 6, a middle flat tunnel construction branch hole 7, and a lower flat tunnel construction branch hole 8. A drainage pipe 1 is sequentially connected between the upper reservoir opening and closing machine room, the upper flat tunnel construction branch hole 6, the middle flat tunnel construction branch hole 7, the lower flat tunnel construction branch hole 8, and the powerhouse. A first throttling orifice 5 is provided on the drainage pipe 1 between the upper flat tunnel construction branch hole 6 and the middle flat tunnel construction branch hole 7, a second throttling orifice 51 is provided on the drainage pipe 1 between the middle flat tunnel construction branch hole 7 and the lower flat tunnel construction branch hole 8, and a first working ball valve 2, a second working ball valve 21, and a third working ball valve 22 are respectively provided on the drainage pipes 1 on one side of the upper flat tunnel construction branch hole 6, the middle flat tunnel construction branch hole 7, and the lower flat tunnel construction branch hole 8.

[0015] The first throttling orifice plate 5 and the second throttling orifice plate 51 are arranged at different classification stages to converge water flow.

[0016] A first maintenance pipe 4 is provided on the drainage pipe 1 on one side of the upper flat tunnel construction branch tunnel 6 , and a first maintenance butterfly valve 3 is provided on the first maintenance pipe 4 .

[0017] A second inspection pipe 41 is provided on the drainage pipe 1 on one side of the Zhongping tunnel construction branch tunnel 7 , and a second inspection butterfly valve 31 is provided on the second inspection pipe 41 .

[0018] The first inspection pipe 4 and the second inspection pipe 41 serve as branches of the drainage pipe 1 , and a first inspection butterfly valve 3 and a second inspection butterfly valve 31 are respectively provided for the inspection of the corresponding branches.

[0019] In this embodiment, the upper flat tunnel construction branch hole 6 is located downstream of the upper reservoir inlet / outlet, passing through a drainage pipe 1 to a first service ball valve 2. A first inspection drainage pipe 4 is provided in the middle of the drainage pipe 1 for inspecting the problematic portion of the upper flat tunnel construction branch hole 6. A first inspection butterfly valve 3 is also provided on the first inspection drainage pipe 4. If the problem is only at the upper flat tunnel construction branch hole 6, simply opening the first inspection butterfly valve 3 of the upper flat tunnel construction branch hole 6 is sufficient.

[0020] The Zhongping tunnel construction branch tunnel 7 is located downstream of the Shangping tunnel construction branch tunnel 6. As it flows downward, it passes through the first throttling orifice 5 and is divided into two stages, 1 and 2. The hydraulic head gradually decreases, remaining constant for the first three stages before gradually decreasing. A second working ball valve 21, a second inspection pipe 41, and a second inspection butterfly valve 31 are installed. If the upper inclined shaft (vertical shaft) or Zhongping tunnel construction branch tunnel 7 needs to be drained for maintenance, only Zhongping tunnel construction branch tunnel 7 and above need to be drained.

[0021] The lower flat tunnel construction branch tunnel 8 is located on the downstream side of the middle flat tunnel construction branch tunnel 7. It goes downward and is divided into two levels 1 and 2 through the second throttling orifice 51. The water head decreases and the regulated pressure also decreases. It passes through the third working ball valve 22 and finally flows into the main powerhouse.

[0022] Drainage is carried out in eight stages:

[0023] ① Drainage from the vent holes of the upper reservoir gate well and the upstream surge well;

[0024] ② Drainage of the gradient section, Xiaoping section, and upstream surge well behind the upper reservoir gate well;

[0025] ③ Drainage from the upper inclined well and upstream surge well;

[0026] ④ Drainage of upper level tunnel and upstream surge well;

[0027] ⑤ Drainage of medium inclined well;

[0028] ⑥ Drainage of the middle level tunnel;

[0029] ⑦ Drainage of inclined well;

[0030] ⑧ Drainage from the lower level tunnel, water diversion branch pipe, and water diversion branch pipe.

[0031] In this embodiment, the upper flat tunnel, the middle flat tunnel and the drainage pipe inlet are located in the tunnel and buried in the plug. An inspection butterfly valve (the first inspection butterfly valve 3 and the second inspection butterfly valve 31) is set about 50 cm outside the plug, and a working ball valve (the first working ball valve 2, the second working ball valve 21, and the third working ball valve 22) is set about 150 cm towards the construction branch tunnel of the inspection butterfly valve. The diameter of the first throttling orifice 5 and the second throttling orifice 51 is 30% of the drainage pipe.

[0032] According to the description and drawings of the present invention, those skilled in the art can easily manufacture or use the hierarchical pressure reducing and drainage structure of the high head power station water diversion system of the present invention, and can produce the positive effects described in the present invention.

[0033] It should be noted that the terms "including" and "having" in the specification and claims of the present invention and the above-mentioned drawings, as well as any variations thereof, are intended to cover non-exclusive inclusions. The terms "installed", "set", "provided with", "connected", "connected", and "socketed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be an internal connection between two mechanisms, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0034] In the description of this utility model, it should be understood that terms such as "one end," "the other end," "outer side," "inner side," "horizontal," "end," "length," "outer end," "left," and "right" indicate positions or locations based on the positions or locations shown in the accompanying drawings. These terms are used solely to facilitate the description of this utility model and to simplify the description. They do not indicate or imply that the mechanisms or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this utility model. The terms "first" and "second" are used solely for brevity of description and do not indicate or imply relative importance.

[0035] Furthermore, in practicing the claims of the present invention, those skilled in the art may understand and effect variations to the disclosed embodiments by studying the drawings, the disclosure, and the appended claims. Furthermore, in the claims and the specification, words such as "comprising" and "including" do not exclude other elements or steps, and non-plural nouns do not exclude their plural forms.

[0036] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of implementation of the present invention. All equivalent changes and modifications made based on the present invention are covered by the scope of the claims of the present invention and will not be listed one by one here.

Claims

1. A hierarchical pressure reduction and drainage structure for a high-head power station water diversion system, arranged between the upstream upper reservoir opening and closing machine room and the downstream main powerhouse, characterized in that: The utility model comprises an upper flat tunnel construction branch hole (6), a middle flat tunnel construction branch hole (7), and a lower flat tunnel construction branch hole (8); a drainage pipe (1) is sequentially connected between the upper storage opening and closing machine room, the upper flat tunnel construction branch hole (6), the middle flat tunnel construction branch hole (7), the lower flat tunnel construction branch hole (8), and the factory building; a first throttling orifice plate (5) is provided on the drainage pipe (1) between the upper flat tunnel construction branch hole (6) and the middle flat tunnel construction branch hole (7); a second throttling orifice plate (51) is provided on the drainage pipe (1) between the middle flat tunnel construction branch hole (7) and the lower flat tunnel construction branch hole (8); a first working ball valve (2), a second working ball valve (21), and a third working ball valve (22) are respectively provided on the drainage pipes (1) on one side of the upper flat tunnel construction branch hole (6), the middle flat tunnel construction branch hole (7), and the lower flat tunnel construction branch hole (8).

2. A hierarchical pressure reduction and drainage structure for a high head power station water diversion system according to claim 1, characterized in that: A first inspection pipe (4) is provided on the drainage pipe (1) on one side of the upper horizontal tunnel construction branch tunnel (6), and a first inspection butterfly valve (3) is provided on the first inspection pipe (4).

3. A hierarchical pressure reduction and drainage structure for a high head power station water diversion system according to claim 1 or 2, characterized in that: A second inspection pipe (41) is provided on the drainage pipe (1) on one side of the central flat tunnel construction branch tunnel (7), and a second inspection butterfly valve (31) is provided on the second inspection pipe (41).

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