Calculation method and system for setting feasibility of pumped storage power station unit and surge chamber

Abstract

The invention provides a calculation method and system for setting feasibility of a pumped storage power station unit and a surge chamber, and the calculation method comprises the steps: executing a first judgment, namely judging whether SY is greater than or equal to L-SW and L-SZ1 is smaller than or equal to 0, and judging whether SY is greater than or equal to L-SW and L-SZ1 is smaller than or equal to 0; if the first judgment result is yes, the surge chamber is not set, and the value range of xc is [L-SW, min (SY, L)]; and if the first judgment result is no, determining the type of the surge chamber, the arrangement position range of the surge chamber on the x axis and the value range of xc according to whether SY + Syt is greater than or equal to L-SW and whether Syt is greater than or equal to L-SZ1.

Description

Technical Field

[0001] The present invention belongs to the field of engineering design of pumped storage power stations, and more specifically, relates to a method for intelligent calculation of underground plant units and surge chambers in pumped storage power stations. Background Art

[0002] A pumped storage power station is a special form of power station, which consists of an upper reservoir, a lower reservoir, a water transmission system, a plant, etc. The water transmission system of a pumped storage power station usually has the characteristics of large height difference and long water transmission line. When the load of the power station unit changes, the automatic opening and closing of the guide vane of the pump turbine will cause water hammer in the waterway. Since the water hammer pressure is mainly caused by the inertia of the water body in the pressure waterway, the longer the waterway, the greater the water hammer pressure. For pumped storage power stations with long water transmission systems, the water hammer pressure is often reduced by arranging a surge chamber. The surge chamber is actually a cylindrical or well-type building with a free water surface. The setting of the surge chamber can cause the reflection of water hammer waves like a reservoir, prevent excessive water hammer pressure from propagating to the pressure water channel, reduce the water hammer value in the high-pressure pipeline (the tail water is the pressure pipeline), and improve the operating conditions and power supply quality of the unit when the load changes. There are four main types of surge chamber layouts for pumped storage power stations: no surge chamber is required, only a diversion surge chamber (100) is provided, only a tailwater surge chamber (200) is provided, and both a diversion surge chamber and a tailwater surge chamber are provided. The surge chambers are mostly impedance surge chamber structures.

[0003] Although the surge chamber has the above functions, the installation of a surge chamber will increase the project investment. Therefore, whether a surge chamber is needed in the water transmission system and what kind of surge chamber to install need to be comprehensively considered according to the layout of the power station's pressure waterway, topographic and geological conditions, unit operating parameters, etc. In addition, the underground powerhouse is also an important building in the water transmission and power generation system. According to the position of the underground powerhouse in the water transmission system, it can be divided into three types: head type, middle type and tail type. That is, on the water transmission line, the underground powerhouse can be arranged near the upper reservoir, in the middle between the upper reservoir and the lower reservoir, and near the lower reservoir. The type and location of the powerhouse are also closely related to the setting of the surge chamber. Choosing a suitable powerhouse location has a significant impact on the operation of the power station and the project cost.

[0004] At present, in the preliminary design stage of the water transmission and power generation system of the pumped storage power station, the location of the upper and lower reservoirs, the characteristic water level of the power station, the external boundary parameters such as the unit parameters, and the topographic and geological conditions are often combined. First, the location of the upper reservoir inlet / outlet and the lower reservoir inlet / outlet is selected, and a suitable plane water transmission line is planned between the upper reservoir inlet / outlet and the lower reservoir inlet / outlet, and the plant location is selected on the plane line, and the elevation type of the water transmission line is arranged. Then, the hydraulic conditions are used to calculate whether the water transmission system needs to be equipped with a surge chamber and what kind of surge chamber to be set. In the layout process, in order to achieve the purpose of meeting the hydraulic requirements of the water transmission system and having a relatively good engineering cost, it is usually necessary to manually adjust the plant location and elevation layout, and repeatedly calculate the layout type of the surge chamber to determine the final layout of the water transmission and power generation system. This method is cumbersome and inefficient. Summary of the invention

[0005] The problem to be solved by the present invention is that in the prior art, it is necessary to manually adjust and select the plant location and facade layout, and repeatedly calculate the layout type of the surge chamber to determine the final layout of the water transmission and power generation system, which makes the steps cumbersome and inefficient. A method for calculating the feasibility of setting up underground plant units and surge chambers in a pumped-storage power station is provided.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: a calculation method for the feasibility of setting up underground powerhouse units and surge chambers in a pumped storage power station;

[0007] A rectangular coordinate system (o, x, y) is constructed, wherein the coordinate origin of the coordinate system is o, and the y-axis direction is the height direction; the x-axis is defined so that a first straight line and a second straight line parallel to each other have a first intersection point and a second intersection point with the x-axis respectively; the spacing between the first intersection point and the second intersection point is L, where L is a preset value; the first straight line is a straight line passing through a set upper reservoir inlet / outlet (10A) position and parallel to the y-axis direction, and the second straight line is a straight line passing through a set lower reservoir inlet / outlet (20A) position and parallel to the y-axis direction;

[0008] The method comprises: performing a first judgment, wherein the first judgment is to judge whether SY≥L-SW and L-SZ1≤0 are simultaneously established;

[0009] If the first judgment result is yes, no surge chamber is set, and the value range of x_c is [L-SW, min(SY, L)];

[0010] If the first judgment result is no, then the type of the surge chamber, the arrangement position range of the surge chamber on the x-axis, and the value range of x_c are determined according to whether SY+Syt≥L-SW and Syt≥L-SZ1 are established;

[0011] in:

[0012] x_c is the distance between the powerhouse unit (30) and the first intersection in the x-axis direction; SY is the maximum distance between the upstream free liquid surface and the powerhouse unit (30) in the x-axis direction; SZ1 is the maximum distance between the upstream free liquid surface and the downstream free liquid surface in the x-axis direction when a tailwater surge chamber is not provided; SW is the maximum distance between the powerhouse unit (30) and the lower reservoir inlet / outlet (20A) in the x-axis direction when a tailwater surge chamber (200) is not provided; Syt is the upper limit value of the distance between the water diversion surge chamber (100) and the first intersection in the x-axis direction when a water diversion surge chamber (100) is provided.

[0013] By adopting the above technical solution, the distance between the position of the upper reservoir inlet / outlet (10A) and the position of the lower reservoir inlet / outlet (20A) in the x-axis direction is determined, and the values ​​of SY, SZ1, and SW are calculated, so as to determine whether a surge chamber is required, and the value range of the distance x_c between the plant unit (30) and the upper reservoir inlet / outlet (10A) in the x-axis direction when the surge chamber is not provided can be obtained. If a surge chamber is required, the type of surge chamber required to be provided, the arrangement position range of the surge chamber in the x-axis direction, and the value range of the distance x_c between the plant unit (30) and the upper reservoir inlet / outlet (10A) in the x-axis direction can be determined based on the calculated value of Syt, based on whether SY+Syt≥L-SW is established, and whether Syt≥L-SZ1 is established. By adopting the above scheme, it is possible to determine whether a surge chamber is needed and what type of surge chamber is needed through parameter calculation and size value comparison, and to determine the layout position range of the plant building, as well as the layout position range of the surge chamber when a surge chamber is needed, thereby quickly determining the setting type of the surge chamber, greatly improving the design work efficiency and judgment accuracy, and thus efficiently and accurately determining the layout plan.

[0014] In the above technical solution, according to whether SY+Syt≥L-SW is established and whether Syt≥L-SZ1 is established, the specific method for determining the type of the surge chamber, the arrangement position range of the surge chamber on the x-axis, and the value range of x_c includes:

[0015] If SY+Syt≥L-SW and Syt≥L-SZ1 are satisfied, only the water diversion pressure regulating chamber (100) is provided, the value range of x_y is [L-SW-SY, Syt], and the value range of x_c is [L-SW, min(L, Syt+SY)];

[0016] If any of the conditions SY+Syt≥L-SW and Syt≥L-SZ1 is not met, then:

[0017] ① When the value range of x_c is (0, SY], only the tailwater surge chamber (200) is set, wherein the value range of x_w is [x_c+150 meters, x_c+250 meters], x_w≤SZ2, wherein SZ2 is the maximum distance between the upstream free liquid surface and the downstream free liquid surface in the x-axis direction when the tailwater surge chamber is set;

[0018] ② When the value range of x_c is (SY, SY+Syt], a diversion surge chamber (100) and a tailwater surge chamber (200) are set, wherein the value range of x_y is (max(0, x_c-SY), Syt], the value range of x_w is [x_c+150 meters, x_c+250 meters], and x_w-x_y≤SZ2;

[0019] Wherein: x_y is the distance between the water diversion surge chamber (100) in the x-axis direction and the first intersection point, and x_w is the distance between the tailwater surge chamber (200) in the x-axis direction and the first intersection point.

[0020] In a preferred embodiment, if any one of the conditions SY+Syt≥L-SW and Syt≥L-SZ1 is not satisfied, the value range of the tailwater surge chamber x_w is [x_c+200 meters, x_c+250 meters]. By adopting the above technical solution, according to the calculated value of Syt, according to whether SY+Syt≥L-SW is established, and whether Syt≥L-SZ1 is established, it can be determined which type of surge chamber needs to be arranged, and the coordinate range of the surge chamber on the x-axis and the coordinate range of the powerhouse on the x-axis can be determined accordingly.

[0021] In the above technical solution, SY, SW, SZ1, and SZ2 are obtained according to [L1], [L4], [L14], and [L15] respectively; wherein: [L1] is the value that makes T w ≤[T w ] The maximum permissible length of the established pressure pipe (1);

[0022] [L4] To make T ws ≤[T ws ] The maximum permissible length of the pressure tailrace (4) established;

[0023] [L14] is when no tailwater surge tank is provided, so that T w1 ≤[T w1 ]The maximum permissible length of the pipeline from the upstream free liquid surface to the downstream free liquid surface;

[0024] [L15] is the setting of tailwater surge tank so that T w1 ≤[T w1 ]The maximum permissible length of the pipeline from the upstream free liquid surface to the downstream free liquid surface;

[0025] T w is the water flow inertia time constant of the pressure pipe and the volute section of the unit, [T w ] is T w The maximum permissible value of

[0026] T ws is the inertia time constant of the water flow in the tailrace and tailrace pipe, [T ws ] is T ws The maximum permissible value of

[0027] T w1 is the inertial time constant of the water flow in the pipe between the upstream free liquid surface and the downstream free liquid surface, [T w1 ] is T w1 The maximum allowed value.

[0028] By adopting the above technical solutions, T w ≤[T w ]、T ws ≤[T ws ]、T w1 ≤[T w1 ] is required to calculate [L1], [L4], [L14], and then calculate SY, SW, SZ1, SZ2. In the present invention, when calculating the maximum spacing SW, SY, SZ1, SZ2, the length of the unit volute section 2 and the tailwater pipe 3 in the x-axis direction is not considered.

[0029] In the above technical solution:

[0030] SY≈[L1]-H1, H1 is the distance between the normal water level of the upper reservoir (10) and the installation elevation of the powerhouse unit (30) on the y-axis;

[0031] SW≈[L4]-H2, H2 is the distance between the normal water level of the lower reservoir (20) and the installation elevation of the powerhouse unit (30) on the y-axis;

[0032] SZ1≈[L14]-H1-H2;

[0033] SZ2≈[L15]-H1.

[0034] By adopting the above technical solution and using an estimation method, the values ​​of SY, SW, SZ1, and SZ2 can be calculated using [L1], [L4], [L14], and [L15] respectively.

[0035] In the above technical solution:

[0036]

[0037]

[0038]

[0039] Among them, L1, L2, L3, L4, L 4 / 5 They correspond to the length of the pressure pipe (1), the length of the unit volute section (2), the length of the tailwater pipe (3), the length of the pressure tailwater channel (4), and the length of the pipe from the end of the tailwater pipe (3) to the downstream free liquid surface, v1, v2, v3, v4, and v 4 / 5 They correspond to the average flow velocity in the pressure pipe (1), the average flow velocity in the unit volute section (2), the average flow velocity in the tailwater pipe (3), the average flow velocity in the pressure tailwater channel (4), and the average flow velocity in the pipeline between the end of the tailwater pipe (3) and the downstream free liquid surface; g is the gravitational acceleration; H p is the design water head, H s H is the turbine suction height; p , H s , v1, v4, v 4 / 5 , L2v2, L3v3 are all preset values;

[0040] When the tailwater surge tank (200) is not provided, L 4 / 5 =L4,v 4 / 5 = v4; when the tailwater surge chamber (200) is set, L 4 / 5 =L5,v 4 / 5 =v5; wherein L4 and L5 correspond to the length of the pressure tailwater channel (4) and the length of the tailwater extension pipeline (5), respectively; v4 and v5 correspond to the average flow velocity in the pressure tailwater channel (4) and the average flow velocity in the tailwater extension pipeline (5), respectively.

[0041] In the above technical solution: 2s≤[T w ]≤4s;[T ws ]=4s;[T w1 ] Calculate using the following formula:

[0042]

[0043] Among them, T a is the unit acceleration time constant.

[0044] By adopting the above technical solution, [T w ]、[T ws ]、[T w1 ] preset value.

[0045] In the above technical solution:

[0046] When the water diversion pressure regulating chamber (100) is not provided, the position of the water inlet / outlet (10A) of the upper reservoir is the upstream free liquid surface position; when the water diversion pressure regulating chamber (100) is provided, the position of the water diversion pressure regulating chamber (100) is the upstream free liquid surface position;

[0047] When the tailwater surge chamber (200) is not provided, the position of the lower reservoir inlet / outlet (20A) is the downstream free liquid surface position; when the tailwater surge chamber (200) is provided, the position of the tailwater surge chamber (200) is the downstream free liquid surface position.

[0048] In the above technical solution, the calculation method of Syt is: taking the x-axis coordinate of the point whose y-axis coordinate is y=HL+HU in the intersection line of the first virtual plane and the terrain line of the three-dimensional terrain model as Syt;

[0049] The first virtual plane is a plane formed by the x-axis and the y-axis; HL is the maximum surge setting value considering the margin, and HU is the normal water level of the upper reservoir (10).

[0050] By adopting the above technical solution, the present invention determines the top elevation of the water diversion surge chamber by considering the sum of the highest surge with a certain margin and the normal water level of the upper reservoir, that is, the top elevation of the water diversion surge chamber = the water level of the upper reservoir + the highest surge height. The maximum distance Syt that the water diversion surge chamber can be set from the water inlet / outlet of the upper reservoir can be determined by the intersection position of the top elevation of the water diversion surge chamber and the topographic line on the longitudinal section. Among them, the water diversion surge chamber can be regarded as a point on the x-axis.

[0051] In the above technical solution, the coordinate of the first intersection on the x-axis is x=0, and the coordinate of the second intersection on the x-axis is x=L. When the coordinate of the first intersection on the x-axis is x=0, x_c, x_y, and x_w correspond to the coordinates of the powerhouse unit (30), the water diversion surge chamber (100), and the tailwater surge chamber (200) on the x-axis, respectively.

[0052] Based on the same inventive concept, the present invention also provides a system for calculating the location of underground plant units in a pumped-storage power station, characterized in that it includes a processor configured to execute the steps of the above-mentioned method for calculating the feasibility of setting up underground plant units and surge chambers in a pumped-storage power station.

[0053] The benefits of the present invention are as follows: in the preliminary design stage of the water transmission and power generation system of the pumped storage power station, by drawing up the plane line between the inlet / outlet of the upper reservoir and the inlet / outlet of the lower reservoir, combined with the water energy planning and electromechanical parameters, the location of the water transmission system plant and whether a surge chamber needs to be set up, and what kind of surge chamber needs to be set up are intelligently judged from the hydraulic perspective, and the design personnel are assisted to quickly determine the plant development method and the surge chamber setting type, which greatly improves the design work efficiency and judgment accuracy. After the plane line is determined, the plant location and surge chamber layout type in the water transmission system layout are automatically judged, helping the designers to efficiently and accurately determine the layout plan. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0055] Figure 1 A schematic diagram of a method for calculating the design position of a pumped storage power station building and a surge chamber according to the present invention;

[0056] FIG2(a) is a side cross-sectional view of the water delivery line arrangement between the upper reservoir and the lower reservoir when only the water diversion surge chamber is provided;

[0057] FIG2( b ) is a side cross-sectional view of the water delivery line arrangement between the upper reservoir and the lower reservoir when only the tailwater surge chamber is provided;

[0058] FIG2(c) is a side cross-sectional view of the arrangement of the water delivery line between the upper reservoir and the lower reservoir when a water diversion surge chamber and a tailwater surge chamber are provided;

[0059] FIG2( d ) is a side cross-sectional view of the water delivery line arrangement between the upper reservoir and the lower reservoir when no surge chamber is provided;

[0060] Figure 3 It is a partial top view schematic diagram of the volute section and tailwater pipe of the unit;

[0061] Figure 4 It is a schematic diagram for distinguishing the positions of the plant and the surge chamber in the rectangular coordinate system oxy in a specific embodiment of the present invention.

[0062] In the above drawings: 1—pressure pipe; 2—unit volute section; 3—tailwater pipe; 4—pressure tailwater channel; 5—tailwater extension pipe; 6—pressure water diversion channel; 10—upper reservoir; 20—lower reservoir; 10A—upper reservoir inlet / outlet; 20A—lower reservoir inlet / outlet; 100—water diversion surge chamber; 200—tailwater surge chamber. DETAILED DESCRIPTION

[0063] The following will be combined with the drawings of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0064] The present invention proposes a method for intelligent calculation of the setting of underground powerhouse and surge chamber in pumped-storage power station. The method mainly estimates the vertical line length of the water delivery system through the horizontal distance and height difference between the upper reservoir inlet / outlet 10A and the lower reservoir inlet / outlet 20A, combined with water energy planning and electromechanical parameters, and then automatically determines the layout type of the surge chamber and the corresponding plant layout range in the water delivery system through the hydraulic discrimination conditions of the water diversion surge chamber 100 and the tailwater surge chamber 200 of the pumped-storage power station. In this application, the plant layout position is the unit layout position. The present invention uses an algorithm to automatically determine the setting of the water diversion surge chamber and the tailwater surge chamber of the water delivery line, and according to the surge chamber layout, the layout range of the underground powerhouse unit is determined.

[0065] The preliminary judgment conditions for setting up diversion and tailwater surge chambers proposed in the "Design Specifications for Surge Chambers in Hydropower Stations" (NB / T 35021-2014) (hereinafter referred to as the Specifications) can be used as the basis for judging the setting of surge chambers in pumped-storage power stations.

[0066] According to the specification, based on the preliminary judgment of the waterway characteristics, the conditions for setting the water diversion surge chamber 100 are judged according to the following formula:

[0067]

[0068] Where, T w Refers to the water flow inertia time constant of the pressure pipe and the unit volute section, unit s; L1, L2 correspond to the length of the pressure pipe 1, the length of the unit volute section 2, v1, v2 correspond to the average flow velocity in the pressure pipe 1, the average flow velocity in the unit volute section 2, g is the acceleration of gravity, unit m / s 2 ;H p is the design water head of the power station, in m; [T w ] is T w The allowable value is generally 2s-4s.

[0069] When the water diversion pressure regulating chamber 100 is not set, the pressure pipeline 1 is the pipeline between the upper reservoir inlet / outlet 10A and the unit volute section 2; when the water diversion pressure regulating chamber 100 is set, the pressure pipeline 1 is the pipeline between the water diversion pressure regulating chamber 100 and the unit volute section 2.

[0070] Without setting the tailwater surge chamber 200, and on the premise that no liquid column separation occurs in the tailwater pipe, the pumped storage power station can be preliminarily identified by the following formula:

[0071]

[0072] Where, T ws is the inertia time constant of the water flow in the tail race and the tail race, in seconds; L3 and L4 correspond to the length of the tail race 3 and the length of the tail race 4, respectively; v3 and v4 correspond to the average flow velocity in the tail race 3 and the average flow velocity in the tail race 4, respectively; g is the acceleration due to gravity, H s is the turbine suction height, in m. ws Meet T ws When ≤4s, the tailwater surge chamber 200 may not be provided.

[0073] When the tailwater pressure regulating chamber 200 is not provided, the pressure tailwater channel 4 is a pipeline between the outlet of the tailwater pipe section 3 of the unit and the inlet / outlet 20A of the lower reservoir.

[0074]

[0075] T w1 is the inertia time constant of water flow in the pipe between the upstream free liquid surface and the downstream free liquid surface (i.e., the inertia time constant of water flow in the pressure water channel between the upstream and downstream free water surfaces), unit s; L1, L2, L3, L4, L5 correspond to the length of pressure pipe 1, the length of unit volute section 2, the length of tailwater pipe 3, the length of pressure tailwater channel 4, and the length of tailwater extension pipe 5, respectively; v1, v2, v3, v4, v5 correspond to the average flow velocity in pressure pipe 1, the average flow velocity in unit volute section 2, the average flow velocity in tailwater pipe 3, the average flow velocity in pressure tailwater channel 4, and the average flow velocity in tailwater extension pipe 5, respectively.

[0076] As shown in FIG. 2( a ) and FIG. 2( d ), when the tailwater surge chamber 200 is not provided, L 4 / 5 =L4,v 4 / 5 =v4. As shown in FIG2(b) and FIG2(c), when the tailwater surge chamber 200 is provided, L 4 / 5 =L5,v 4 / 5 =v5.

[0077] The closer the powerhouse is to the upper reservoir, the longer the auxiliary cavern connected to the powerhouse is, the longer the construction period is, and the greater the project investment is. Therefore, in pumped storage power stations, considering factors such as powerhouse traffic, ventilation, outgoing line length, and construction period, the tail-type or middle-type layout scheme is often given priority, that is, the underground powerhouse is given priority to be arranged in the middle part between the upper reservoir and the lower reservoir, or close to the lower reservoir.

[0078] The setting of a surge chamber also involves the issue of project investment. The setting of a surge chamber may increase the investment by tens of millions. According to the method of the present invention, it is possible to analyze whether there is a suitable unit location when arranging the water supply system, so that the entire system can be equipped with no surge chamber or only with a diversion or tailwater surge chamber, thereby minimizing the number of surge chambers and reducing investment.

[0079] like Figure 1 As shown, the present invention proposes a method for intelligent calculation of the layout of underground powerhouses and surge chambers in a pumped storage power station, comprising the following steps:

[0080] Step 1: Based on the topographic and geological conditions, the location of the upper and lower reservoirs / dam sites, the external boundaries such as hydraulic and electromechanical parameters, and combined with user experience, the locations of the upper reservoir inlet / outlet 10A and the lower reservoir inlet / outlet 20A are manually selected, and a plan route for the water transfer system is planned.

[0081] Step 2: Based on the three-dimensional terrain model, cut the longitudinal topographic line along the plane line of the water delivery system, and establish a rectangular coordinate system on the longitudinal section view. The horizontal coordinate x-axis is the plane line distance between the upper reservoir inlet / outlet 10A and the lower reservoir inlet / outlet 20A, and the vertical coordinate y-axis is the elevation. The horizontal coordinate x=0 at the position of the upper reservoir inlet / outlet 10A, the proposed plane line length between the upper reservoir inlet / outlet 10A and the lower reservoir inlet / outlet 20A is L, then the horizontal coordinate x=L at the position of the lower reservoir inlet / outlet 20A. The position coordinates x of the powerhouse and surge tank should be between (0, L).

[0082] Step 3: Determine the permissible value of the water flow time inertia constant. Assuming that there is no surge chamber control, the permissible values ​​of the three water flow inertia time constants are [T w ]、[T w1 ]、[T ws ], according to the specification, [T w ] Generally, it takes 2s to 4s. Where T a It is the unit acceleration time constant (preset value), unit is s. [T ws ]4s is acceptable.

[0083] According to the specification, [T ws ] mainly reflects that the tailwater system allowable length does not need to be set up with a tailwater surge tank 200. When the actual calculated value T ws >[T ws ], it indicates that the tailwater system waterway is too long and it is necessary to consider setting up a tailwater surge chamber 200.

[0084] [T w] mainly reflects the allowable length of the waterway of the water diversion system from the upstream free liquid surface to the powerhouse. When no surge chamber is set, the upstream free liquid surface is the position of the upper reservoir. When a water diversion surge chamber 100 is set, the upstream free liquid surface is the position of the water diversion surge chamber 100. The actual calculated value T when no water diversion surge chamber 100 is set w >[T w ], it is necessary to consider setting up a water diversion and pressure regulating chamber 100 to move the upstream free liquid surface back closer to the powerhouse.

[0085] [T w1 ] mainly reflects the allowable length of the pressure channel of the water delivery system from the upstream free liquid surface to the downstream free liquid surface. The upstream free liquid surface is as described above. Similarly, when the tailwater surge chamber 200 is not set, the downstream free liquid surface is the lower reservoir. When the tailwater surge chamber 200 is set, the tailwater surge chamber 200 is used as the new downstream free liquid surface. When the surge chamber is not set, the actual calculated value T w1 >[T w1 ], it is necessary to consider setting up a diversion pressure regulating chamber 100 and / or a tailwater pressure regulating chamber 200, that is, it may be necessary to set up one of the pressure regulating chambers, or it may be necessary to set up both a diversion pressure regulating chamber and a tailwater pressure regulating chamber.

[0086] Step 4: In the rectangular coordinate system of the longitudinal section, the position coordinate of the upstream free liquid surface on the x-axis is xs, the position coordinate of the downstream free liquid surface on the x-axis is xx, and the coordinate of the plant layout position on the x-axis is x_c.

[0087] Since the water supply system of a pumped-storage power station usually has the characteristics of large height difference and long water supply line, the water supply system of a large pumped-storage power station project has a height difference of about several hundred meters and a horizontal distance of about one or two kilometers. In the early design of the scheme, the vertical height difference + horizontal distance is used to preliminarily estimate the length of the pressure waterway. Although it is different from the actual layout, the accuracy is still acceptable and can assist in determining the general direction of the scheme, that is, determining whether a surge chamber is needed and whether a water diversion or tailwater surge chamber is needed. After the general direction of the scheme is determined, the designers can also carry out detailed layout, and make local adjustments to the plant location, surge chamber layout location, and pipeline layout.

[0088] (4.1) According to [T ws] Calculate the maximum horizontal distance SW between the plant and the inlet / outlet 20A of the lower reservoir without the tailwater surge chamber 200. In the early stage of scheme design, the length of the pressure tailwater channel can be approximately estimated according to the sum of the horizontal length and vertical height of the pipeline from the plant to the inlet / outlet 20A of the lower reservoir. The difference between the normal water storage level of the lower reservoir and the installation elevation of the plant unit is taken as the vertical height. The flow rate of the pressure tailwater channel can be preliminarily determined as an economic flow rate of 4-5m / s according to engineering experience. The normal water storage level of the lower reservoir, the installation elevation of the unit, the suction height of the turbine, the length and flow rate of the tailwater pipe (i.e., L value, V value) are all hydropower planning and electromechanical parameters, which are upstream professional parameters when arranging the water transmission and power generation system of the power station, and can be regarded as known quantities. Therefore, the maximum horizontal distance SW between the plant building and the lower reservoir inlet / outlet 20A when the tailwater surge chamber 200 is not required can be calculated. In the vertical coordinate system, the extreme position coordinate x of the plant building without the tailwater surge chamber 200 is x=(L-SW)=Lw, so the range of the plant building position coordinate x without the tailwater surge chamber 200 should be [Lw, L).

[0089] (4.2) Similarly, according to [T w ]The maximum horizontal distance SY between the upstream free liquid surface and the powerhouse can be calculated, where the volute length and flow rate (i.e., LV value) and the design head are water energy planning and electromechanical parameters, which can be regarded as known quantities. The length of the pressure pipeline is approximately estimated according to the sum of the horizontal length and vertical height of the pipeline. The difference between the normal water level of the upper reservoir and the installation elevation of the powerhouse unit is taken as the vertical height. The flow rate of the pressure pipeline can be preliminarily set as an economic flow rate of 4-5m / s according to engineering experience. Under the condition that other variables are determined, the maximum horizontal distance SY between the upstream free liquid surface and the powerhouse can be calculated. Then the allowable interval of the horizontal distance from the upstream free liquid surface to the powerhouse should be [Ly1, Ly2] = [xs, xs + SY]. [T w ] The control interval is actually a fixed length interval range of SY, the left end value of the interval is the upstream free surface position, and the right end value satisfies [T w ] The farthest layout position of the unit required by the control, when the plant layout position is within this range, can meet T w ≤[T w ], the upstream free liquid surface position can be moved on the x-axis. In the present invention, the vertical height difference + horizontal distance is used to preliminarily estimate the length of the pressure tail raceway. Although there is a difference from the actual layout, the accuracy is still acceptable.

[0090] (4.3) Based on the treatment of the length of the pressure pipe and the pressure tail raceway in (4.1) and (4.2), the length of the pressure pipe and the pressure tail raceway can be calculated according to [T w1] Calculate the maximum horizontal distance SZ1 allowed between the upstream and downstream free liquid surfaces when no tailwater surge tank is set. Then the allowable horizontal distance range between the upstream free liquid surface and the downstream free liquid surface is [Lz1, Lz2] = [xx-SZ1, xx]. [T w1 The control interval is actually a fixed length SZ1 interval. Since the powerhouse location is usually preferred to be tail-end layout (i.e., the powerhouse is located close to the lower reservoir), no tailwater surge chamber 200 is provided. Therefore, the right end value of the interval, i.e., the downstream free liquid surface, can be used as the starting point, and the left end value of the interval can be used to meet T w1 ≤[T w1 ]The farthest upstream free liquid surface layout position required by the control.

[0091] Step 5: Since pumped storage power stations usually require the top of the surge chamber to be higher than the highest surge water level, this type of layout requires that the water diversion channel has suitable terrain conditions that are sufficiently higher than the normal water level of the upper reservoir. When this terrain condition is not met, it is not appropriate to use a water diversion impedance surge chamber. According to engineering experience, the highest surge for setting up a water diversion surge chamber 100 is usually between 20m and 35m. According to the specification, the elevation of the top of the surge chamber can be determined in the early stage by considering a certain margin of the highest surge + the normal water level of the upper reservoir. According to the longitudinal profile terrain line obtained by cutting the plane line, the maximum distance Syt from the inlet / outlet 10A of the upper reservoir where the water diversion surge chamber 100 can be set can be determined by the intersection of the top elevation of the water diversion surge chamber 100 and the terrain line on the longitudinal section.

[0092] Step 6: Determine the setting of the surge chamber and the powerhouse. The basic process of determining the setting of the surge chamber is: give priority to the tail-end powerhouse layout, do not set up the tailwater surge chamber 200, determine whether there are conditions to not set up the diversion surge chamber 100, if it cannot meet the requirements, determine whether only the diversion surge chamber 100 or the tailwater surge chamber 200 can be set up, and finally determine whether it is necessary to set up upstream and downstream double surge chambers (that is, set up both the diversion surge chamber and the tailwater surge chamber).

[0093] First, consider the case where there is no surge chamber. In this case, the upstream free liquid surface is the upper reservoir position, and the downstream free liquid surface is the lower reservoir position, that is, xs = 0, xx = L. Then [T w ]Control interval range [Ly1, Ly2] = [xs, xs + SY] = [0, SY], [T w1 ]’s control interval range is [Lz1, Lz2] = [xx-SZ1, xx] = [L-SZ1, L].

[0094] (6.1) When Ly2≥Lw, Lz1≤xs, it means that the water supply system does not require a surge chamber, and the recommended plant layout range is [Lw, min(Ly2, L)].

[0095] (6.2) When Ly2<Lw, Lz1≤xs, it means that the distance between the upstream and downstream free liquid surfaces meets the requirements (T w1 ≤[T w1 ]), while the distance from the upstream free liquid surface to the unit is too large (T w >[T w ]). Priority should be given to setting up a water diversion pressure regulating chamber 100 to move the upstream free liquid surface backward and shorten the length of the pressure pipeline, thereby reducing T w Since the closer the water diversion and pressure regulating chamber 100 is to the lower reservoir, the better its regulating performance is, after the farthest position selection of the water diversion and pressure regulating chamber 100 has been completed in the early stage, the water diversion and pressure regulating chamber 100 can be directly considered to be arranged at the extreme position, at which time [T w ]The farthest location of the factory building required by control is at Syt+SY.

[0096] If Syt+SY≥Lw, it means that the requirement can be met by only setting up the water diversion pressure regulating chamber 100. At this time, the upstream free liquid surface position xs=Syt, [T w ]The control interval [xs, xs+SY] = [Syt, Syt+SY], and the recommended plant layout range is [Lw, min(L, Syt+SY)].

[0097] If Syt+SY<Lw, it means that only the water diversion surge tank 100 cannot meet [T w ] requirements. In this case, the plant needs to be moved forward. Two layout types are recommended:

[0098] When the plant layout interval range is (0, SY], only the tailwater surge chamber 200 may be set without the diversion surge chamber 100, and the appropriate locations of the tailwater surge chamber and the plant are selected according to the construction conditions; the value range of x_w is [x_c+150 meters, x_c+250 meters], preferably the value range of x_w is [x_c+200 meters, x_c+250 meters], and x_w≤SZ2 must be satisfied, where SZ2 is the maximum distance from the upstream free liquid surface to the downstream free liquid surface in the x-axis direction when the tailwater surge chamber is set.

[0099] When the plant layout interval range is (SY, Syt+SY], it is necessary to set up upstream and downstream double surge chambers (that is, set up a diversion surge chamber and a tailwater surge chamber at the same time). At this time, the position of the diversion surge chamber 100 can be considered to be arranged at the extreme position, and the tailwater surge chamber 200 can select the appropriate positions of the diversion surge chamber, the tailwater surge chamber and the plant according to the plant location and structural requirements. The value range of x_y is [max(0, x_c-SY), Syt], and the value range of x_w is [x_c+150 meters, x_c+250 meters]; preferably, the value range of x_w is [x_c+200 meters, x_c+250 meters], and x_w-x_y≤SZ2 must be satisfied.

[0100] (6.3) When Ly2 ≥ Lw, Lz1 > xs, it means that the distance from the upstream free liquid surface to the unit meets the requirements (T w ≤[T w ]), the distance between the upstream and downstream free liquid surfaces is too large (T w1 >[T w1 ]). Priority should be given to setting up a water diversion pressure regulating chamber 100 to move the upstream free liquid surface backward and shorten the length of the pressure pipeline, thereby reducing T w1 Consider that the water diversion surge chamber 100 is arranged at the extreme position Syt.

[0101] If Lz1≤Syt, it means that the requirement can be met by only setting up the water diversion and pressure regulating chamber 100. At this time, the upstream free liquid surface position xs=Syt, and the recommended plant layout range is [Lw, min(L, Syt+SY)].

[0102] If Lz1>Syt, it means that only the water diversion surge tank 100 cannot meet [T w1 ] requirements, it is necessary to set up upstream and downstream double surge chambers. At this time, the water diversion surge chamber 100 can be considered to be arranged at the extreme position. The tailwater surge chamber 200 can be set according to the location of the powerhouse, and a suitable location can be selected in combination with geological conditions and structural requirements. At the same time, the powerhouse layout should not be between (min(Syt+SY, L), L].

[0103] (6.4) When Ly2<Lw, Lz1>xs, it means that the distance from the upstream free liquid surface to the unit and the distance between the upstream and downstream free liquid surfaces are both too large (T w1 >[T w1 ], T w >[T w ]). It is preferred to set up a water diversion pressure regulating chamber 100. It is considered that the water diversion pressure regulating chamber 100 is arranged at the extreme position Syt.

[0104] If Syt+SY≥Lw, and Lz1≤Syt, only the water diversion and surge tank 100 may be provided, and the recommended plant layout range is [Lw, min(L, Syt+SY)].

[0105] If the above two conditions cannot be met at the same time, it means that it is necessary to set up dual upstream and downstream pressure regulating chambers (that is, to set up a water diversion pressure regulating chamber and a tailwater pressure regulating chamber at the same time). At this time, it can be considered to arrange the water diversion pressure regulating chamber 100 at the extreme position, and the tailwater pressure regulating chamber 200 can be located at a suitable position according to the location of the plant and the structural requirements.

[0106] As shown in Figure 2(a), Figure 3 As shown, when only the water diversion surge chamber 100 is provided, the upstream free liquid surface position is the position of the water diversion surge chamber 100, and the downstream free liquid surface is the inlet / outlet 20A of the lower reservoir. A pressure water diversion channel 6 is provided between the inlet / outlet 10A of the upper reservoir and the water diversion surge chamber 100, and a pressure pipe 1 is provided between the water diversion surge chamber 100 and the unit volute section 2, and the pressure pipe 1 is connected to the unit volute section 2, and the outlet of the unit tailwater pipe section 3 is connected to the inlet / outlet 20A of the lower reservoir through the pressure tailwater channel 4.

[0107] As shown in Figure 2(b), Figure 3 As shown, when only the tailwater surge chamber 200 is provided, the upstream free liquid surface is the upper reservoir inlet / outlet 10A, and the downstream free liquid surface position is the position of the tailwater surge chamber 200. Between the upper reservoir inlet / outlet 10A and the unit volute section 2 is a pressure pipe 1, the pressure pipe 1 is connected to the unit volute section 2, the connecting pipe between the outlet of the unit tailwater pipe section 3 and the tailwater surge chamber 200 is a tailwater extension pipe 5, and a pressure tailwater channel 4 is provided between the tailwater surge chamber 200 and the lower reservoir inlet / outlet 20A. In the present invention, the water diversion surge chamber and the tailwater surge chamber are both regarded as a point on the x-axis.

[0108] As shown in Figure 2(c), Figure 3 As shown, when the water diversion surge chamber 100 and the tailwater surge chamber 200 are provided, the upstream free liquid surface position is the position of the water diversion surge chamber 100, and the downstream free liquid surface position is the position of the tailwater surge chamber 200. A pressure diversion channel 6 is provided between the upper reservoir inlet / outlet 10A and the water diversion surge chamber 100, a pressure pipe 1 is provided between the water diversion surge chamber 100 and the unit volute section 2, the pressure pipe 1 is connected to the unit volute section 2, the outlet of the unit tailwater pipe section is connected to the tailwater surge chamber 200 through the connecting pipe as the tailwater extension pipe 5, and a pressure tailwater channel 4 is provided between the tailwater surge chamber 200 and the lower reservoir inlet / outlet 20A.

[0109] As shown in Figure 2(d), Figure 3As shown, when the surge chamber is not provided, the upstream free liquid surface is the upper reservoir inlet / outlet 10A, and the downstream free liquid surface is the lower reservoir inlet / outlet 20A. The pressure pipe 1 is between the upper reservoir inlet / outlet 10A and the unit volute section 2, and the unit tailwater pipe section 3 is connected to the lower reservoir inlet / outlet 20A through the pressure tailwater channel 4.

[0110] In the present invention, SY, SW, SZ1, and SZ2 are obtained according to [L1], [L4], [L14], and [L15], respectively; wherein:

[0111] [L1] is to make T w ≤[T w ] The maximum permissible length of the established pressure pipe (1);

[0112] [L4] To make T ws ≤[T ws ] The maximum permissible length of the pressure tailrace (4) established;

[0113] [L14] is when no tailwater surge tank is provided, so that T w1 ≤[T w1 ]The maximum permissible length of the pipeline from the upstream free liquid surface to the downstream free liquid surface;

[0114] [L15] is the setting of tailwater surge tank so that T w1 ≤[T w1 ]The maximum permissible length of the pipeline from the upstream free liquid surface to the downstream free liquid surface;

[0115] T w is the water flow inertia time constant of the pressure pipe (1) and the volute section (2) of the unit, [T w ] is T w The maximum permissible value of

[0116] T w1 is the inertial time constant of the water flow in the pipe between the upstream free liquid surface and the downstream free liquid surface, [T w1 ] is T w1 The maximum allowable value of T ws is the water flow inertia time constant of the tail race (4) and the tail race (3), [T ws ] is T ws The maximum allowed value.

[0117] SY≈[L1]-H1, H1 is the distance between the normal water level of the upper reservoir (10) and the installation elevation of the powerhouse unit (30) on the y-axis;

[0118] SW≈[L4]-H2, H2 is the distance between the normal water level of the lower reservoir (20) and the installation elevation of the powerhouse unit (30) on the y-axis;

[0119] SZ1≈[L14]-H1-H2;

[0120] SZ2≈[L15]-H1.

[0121]

[0122]

[0123]

[0124] Among them, L1, L2, L3, L4, L 4 / 5 They correspond to the length of the pressure pipe (1), the length of the unit volute section (2), the length of the tailwater pipe (3), the length of the pressure tailwater channel (4), and the length of the pipe from the end of the tailwater pipe (3) to the downstream free liquid surface, v1, v2, v3, v4, and v 4 / 5 They correspond to the average flow velocity in the pressure pipe (1), the average flow velocity in the unit volute section (2), the average flow velocity in the tailwater pipe (3), the average flow velocity in the pressure tailwater channel (4), and the average flow velocity in the pipeline between the end of the tailwater pipe (3) and the downstream free liquid surface; g is the gravitational acceleration; H p is the design water head, H s H is the turbine suction height; p , H s , v1, v4, v 4 / 5 , L2v2, L3v3 are all preset values;

[0125] When the tailwater surge tank (200) is not provided, L 4 / 5 =L4,v 4 / 5 =v4;

[0126] When the tailwater surge chamber (200) is provided, L 4 / 5 =L5,v 4 / 5 =v5;

[0127] Wherein, L4 and L5 correspond to the length of the pressure tailwater channel (4) and the length of the tailwater extension pipe (5), respectively; v4 and v5 correspond to the average flow velocity in the pressure tailwater channel (4) and the average flow velocity in the tailwater extension pipe (5), respectively.

[0128] When calculating [L14], Let T w1 =[T w1 ], the calculated L1+L4 is the value of [L14].

[0129] When calculating [L15], Let T w1 =[T w1 ], the calculated L1+L5 is the value of [L15].

[0130] In order to make the purpose, technical solutions and advantages of the present invention clearer, a pumped storage power station is taken as an example to illustrate the intelligent calculation method for setting up the plant and the surge chamber proposed in the present invention.

[0131] The relevant hydropower planning and electromechanical parameters of the power station are shown in Table 1.

[0132] Table 1: Hydropower planning and electromechanical parameters of a pumped storage power station

[0133] parameter Numeric parameter Numeric Normal water level of upper reservoir 628m Turbine suction height -75m Normal water level of the lower reservoir 150.5m The product value of the volute segment LV <![CDATA[300m 2 / s]]> Design head 470m Product value of tailwater section LV <![CDATA[240m 2 / s]]> Unit installation elevation 50m Unit acceleration time constant 8.456s

[0134] The steps for implementing the intelligent calculation of the plant and surge chamber settings proposed in the present invention are as follows:

[0135] Step 1: Based on the external boundaries such as topographic and geological conditions, the locations of the upper and lower reservoirs / dam sites, hydraulic energy and electromechanical parameters, the locations of the upper reservoir inlet / outlet 10A and the lower reservoir inlet / outlet 20A are manually selected, and a plane layout route is planned.

[0136] Step 2: According to the proposed plane route of the water delivery system, the longitudinal profile topographic line is cut and a rectangular coordinate system is established. The length of the proposed plane route between the upper reservoir inlet / outlet 10A and the lower reservoir inlet / outlet 20A is 1917.2m. The horizontal coordinate x=0 at the position of the upper reservoir inlet / outlet 10A and the horizontal coordinate x=1917.2 at the position of the lower reservoir inlet / outlet 20A.

[0137] Step 3: Determine the permissible value of the water flow time inertia constant. According to the specification and formula, the permissible values ​​of the water flow inertia time constant are [T w ]=2s, [T w1 ]=2.53s, [T ws ]=4s.

[0138] Step 4: In the vertical coordinate system of the water supply line, the position coordinate of the upstream free liquid surface is xs, the position coordinate of the downstream free liquid surface is xx, and the position coordinate of the plant layout is x_c.

[0139] (4.1) According to [T ws ] Calculate the maximum horizontal distance SW between the powerhouse and the lower reservoir inlet / outlet 20A when no tailwater surge chamber 200 is allowed. When calculating, the vertical height difference of the pipeline between the powerhouse and the lower reservoir inlet / outlet 20A is approximately calculated as the normal water level of the lower reservoir - the unit installation elevation = 150.5m-50m = 100.5m. The pressure tailwater flow rate is based on engineering experience and takes the economic flow rate of 5m / s. The turbine suction height and the volute section LV value are known. According to the calculation formula Let T ws =[T ws], the length of the pressure tailwater channel is calculated to be 540.6m, so when the tailwater surge chamber 200 is not provided, the maximum horizontal distance SW between the powerhouse and the lower reservoir inlet / outlet 20A is 540.6m-100.5m=440.1m. Then in the vertical coordinate system, the powerhouse limit position coordinate x without the tailwater surge chamber 200 is x=(L-SW)=1477.1m, and the range of the powerhouse position coordinate x without the tailwater surge chamber 200 should be [1477.1, 1917.2).

[0140] (4.2) Similarly, according to [T w ] The maximum allowable horizontal distance SY between the upstream free liquid surface and the powerhouse can be calculated. When calculating, the vertical height difference of the pressure pipe between the upper reservoir inlet / outlet 10A and the powerhouse is approximately calculated as the normal water level of the upper reservoir - the unit installation elevation = 628m-50m = 578m. The flow rate of the pressure pipe is based on engineering experience and takes the economic flow rate of 5m / s. The design head and the volute section LV value are known. According to the above T w Calculation formula, let T w =[T w ], the calculated length of the pressure pipeline is 1784.3m, then the maximum allowable horizontal distance between the upstream free liquid surface and the power building is SY=1784.28m-578m=1206.3m, and the allowable range of the horizontal distance from the upstream free liquid surface to the power building should be [Ly1, Ly2]=[xs, xs+1206.3].

[0141] (4.3) Based on the treatment of the length of the pressure pipe and the pressure tail raceway in (4.1) and (4.2), the length of the pressure pipe and the pressure tail raceway can be calculated according to [T w1 ] Calculate the maximum horizontal distance between the upstream and downstream free liquid surfaces SZ1 = 1546.5m. The horizontal distance between the upstream free liquid surface and the downstream free liquid surface is allowed to be [Lz1, Lz2] = [xx-1546.5, xx].

[0142] Step 5: Based on engineering experience, consider setting the top platform elevation of the water diversion surge chamber 100 = normal water level of the upper reservoir + 30m = 658m. Figure 4 According to the longitudinal section topographic line obtained by cutting the plane line, the maximum distance Syt=855.9m from the upper reservoir inlet / outlet 10A that the water diversion and pressure regulating chamber 100 can be set is determined by the intersection of the top elevation of the water diversion and pressure regulating chamber 100 and the topographic line on the longitudinal section. Figure 4 shown.

[0143] Step 6: Perform surge chamber setting and plant identification. The basic process for determining the surge chamber setting is: give priority to the tail-end plant layout, do not set up the tailwater surge chamber 200, determine whether there are conditions to not set up the diversion surge chamber 100, if it cannot meet the requirements, determine whether only the diversion surge chamber 100 or the tailwater surge chamber 200 can be set up, and finally determine whether it is necessary to set up upstream and downstream dual surge chambers.

[0144] First, consider the case where there is no surge chamber. In this case, the upstream free liquid surface is the upper reservoir position, and the downstream free liquid surface is the lower reservoir position, that is, xs = 0, xx = L. Then [T w ]Control interval range [Ly1, Ly2] = [0, 1206.3], [T w1 ]'s control interval range [Lz1, Lz2] = [370.7, 1917.2], such as Figure 4 shown.

[0145] like Figure 4 As shown in FIG. 1 , the range of the plant location coordinate x that is allowed not to have the tailwater surge chamber 200 is [1477.1, 1917.2). Since (Ly2=1206.3)<(Lw=1477.1), (Lz1=370.7)>(xs=0), it means that the distance between the upstream and downstream free liquid surfaces is too large (T w1 >[T w1 ]), while the distance from the upstream free liquid surface to the unit is too large (T w >[T w ]). It is preferred to set up the diversion surge chamber 100 to move the upstream free liquid surface backward. The farthest distance that the diversion surge chamber 100 can be set from the upper reservoir inlet / outlet 10A is Syt=855.9m. Since Syt+SY=1206.3+855.9=2062.2, which is greater than 1477.1, and (Lz1=370.7)<(Syt=855.9), it means that the requirement can be met by only setting up the diversion surge chamber 100. The diversion surge chamber 100 is set at x=855.9, at which time the upstream free liquid surface position xs=855.9, [T w ]The control interval [xs, xs+SY] = [855.9, 2062.2], the recommended plant layout range is [Lw, min(L, Syt+SY)] = [1477.1, 1917.2].

[0146] It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0147] The embodiments of the present invention are described in detail above, but the contents are only preferred embodiments of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of this patent. After reading the present invention, modifications of various equivalent forms of the present invention by those skilled in the art all fall within the scope defined by the claims attached to this application. In the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

Claims

1. A method for calculating the feasibility of setting up underground powerhouse units and surge chambers in a pumped storage power station, characterized in that: A rectangular coordinate system (o, x, y) is constructed, wherein the coordinate origin of the coordinate system is o, and the y-axis direction is the height direction; the x-axis is defined so that a first straight line and a second straight line parallel to each other have a first intersection point and a second intersection point with the x-axis respectively; the spacing between the first intersection point and the second intersection point is L, where L is a preset value; the first straight line is a straight line passing through a set upper reservoir inlet / outlet (10A) position and parallel to the y-axis direction, and the second straight line is a straight line passing through a set lower reservoir inlet / outlet (20A) position and parallel to the y-axis direction; The method comprises: performing a first judgment, wherein the first judgment is to judge whether SY≥L-SW and L-SZ1≤0 are simultaneously established; If the first judgment result is yes, no surge chamber is set, and the value range of x_c is [L-SW, min(SY, L)]; If the first judgment result is no, then the type of the surge chamber, the arrangement position range of the surge chamber on the x-axis, and the value range of x_c are determined according to whether SY+Syt≥L-SW and Syt≥L-SZ1 are established; in: x_c is the distance between the powerhouse unit (30) and the first intersection in the x-axis direction; SY is the maximum distance between the upstream free liquid surface and the powerhouse unit (30) in the x-axis direction; SZ1 is the maximum distance between the upstream free liquid surface and the downstream free liquid surface in the x-axis direction when a tailwater surge chamber is not provided; SW is the maximum distance between the powerhouse unit (30) and the lower reservoir inlet / outlet (20A) in the x-axis direction when a tailwater surge chamber (200) is not provided; Syt is the upper limit value of the distance between the water diversion surge chamber (100) and the first intersection in the x-axis direction when a water diversion surge chamber (100) is provided.

2. The method for calculating the feasibility of setting up underground powerhouse units and surge chambers of a pumped storage power station according to claim 1 is characterized by: According to whether SY+Syt≥L-SW and Syt≥L-SZ1 are established, the specific method for determining the type of the surge chamber, the arrangement position range of the surge chamber on the x-axis, and the value range of x_c includes: If SY+Syt≥L-SW and Syt≥L-SZ1 are satisfied, only the water diversion pressure regulating chamber (100) is provided, the value range of x_y is [L-SW-SY, Syt], and the value range of x_c is [L-SW, min(L, Syt+SY)]; If any of the conditions SY+Syt≥L-SW and Syt≥L-SZ1 is not satisfied, then: ① When the value range of x_c is (0, SY], only the tailwater surge chamber (200) is set, wherein the value range of x_w is [x_c+150 meters, x_c+250 meters], x_w≤SZ2, wherein SZ2 is the maximum distance between the upstream free liquid surface and the downstream free liquid surface in the x-axis direction when the tailwater surge chamber is set; ② When the value range of x_c is (SY, SY+Syt], a diversion surge chamber (100) and a tailwater surge chamber (200) are set, wherein the value range of x_y is (max(0, x_c-SY), Syt], the value range of x_w is [x_c+150 meters, x_c+250 meters], and x_w-x_y≤SZ2; Wherein: x_y is the distance between the diversion surge chamber (100) in the x-axis direction and the first intersection point, and x_w is the distance between the tailwater surge chamber (200) in the x-axis direction and the first intersection point; Preferably, if any one of the conditions SY+Syt≥L-SW and Syt≥L-SZ1 is not satisfied, the value range of x_w is [x_c+200 meters, x_c+250 meters].

3. The method for calculating the feasibility of setting up underground powerhouse units and surge chambers of a pumped storage power station according to claim 2, characterized in that: SY, SW, SZ1, SZ2 are obtained according to [L1], [L4], [L14], [L15] respectively; among which: [L1] is to make T w ≤[T w ] The maximum permissible length of the established pressure pipe (1); [L4] To make T ws ≤[T ws ] The maximum permissible length of the pressure tailrace (4) established; [L14] is when no tailwater surge tank is provided, so that T w1 ≤[T w1 ]The maximum permissible length of the pipeline from the upstream free liquid surface to the downstream free liquid surface; [L15] is the setting of tailwater surge tank so that T w1 ≤[T w1 ]The maximum permissible length of the pipeline from the upstream free liquid surface to the downstream free liquid surface; T w is the water flow inertia time constant of the pressure pipe (1) and the volute section (2) of the unit, [T w ] is T w The maximum permissible value of T w1 is the inertial time constant of the water flow in the pipe between the upstream free liquid surface and the downstream free liquid surface, [T w1 ] is T w1 The maximum allowable value of T ws is the water flow inertia time constant of the tail race (4) and the tail race (3), [T ws ] is T ws The maximum allowed value.

4. The method for calculating the feasibility of setting up underground powerhouse units and surge chambers of a pumped storage power station according to claim 3 is characterized by: SY≈[L1]-H1, H1 is the distance between the normal water level of the upper reservoir (10) and the installation elevation of the powerhouse unit (30) on the y-axis; SW≈[L4]-H2, H2 is the distance between the normal water level of the lower reservoir (20) and the installation elevation of the powerhouse unit (30) on the y-axis; SZ1≈[L14]-H1-H2; SZ2≈[L15]-H1.

5. The method for calculating the feasibility of setting up underground powerhouse units and surge chambers of a pumped storage power station according to claim 3 is characterized by: Among them, L1, L2, L3, L4, L 4 / 5 They correspond to the length of the pressure pipe (1), the length of the unit volute section (2), the length of the tailwater pipe (3), the length of the pressure tailwater channel (4), and the length of the pipe from the end of the tailwater pipe (3) to the downstream free liquid surface, v1, v2, v3, v4, and v 4 / 5 They correspond to the average flow velocity in the pressure pipe (1), the average flow velocity in the unit volute section (2), the average flow velocity in the tailwater pipe (3), the average flow velocity in the pressure tailwater channel (4), and the average flow velocity in the pipeline between the end of the tailwater pipe (3) and the downstream free liquid surface; g is the gravitational acceleration; H p is the design water head, H s H is the turbine suction height; p , H s , v1, v4, v 4 / 5 , L2v2, L3v3 are all preset values; When the tailwater surge tank (200) is not provided, L 4 / 5 =L4,v 4 / 5 = v4; when the tailwater surge chamber (200) is set, L 4 / 5 =L5,v 4 / 5 =v5; wherein L4 and L5 correspond to the length of the pressure tailwater channel (4) and the length of the tailwater extension pipeline (5), respectively; v4 and v5 correspond to the average flow velocity in the pressure tailwater channel (4) and the average flow velocity in the tailwater extension pipeline (5), respectively.

6. The method for calculating the feasibility of setting up underground powerhouse units and surge chambers of a pumped storage power station according to claim 3, characterized in that: 2s≤[T w ]≤4s;[T ws ]=4s; [T w1 ] Calculate using the following formula: Among them, T a is the unit acceleration time constant.

7. The method for calculating the feasibility of setting up underground powerhouse units and surge chambers in a pumped storage power station according to any one of claims 1 to 6, characterized in that: When the water diversion pressure regulating chamber (100) is not provided, the position of the water inlet / outlet (10A) of the upper reservoir is the upstream free liquid surface position; when the water diversion pressure regulating chamber (100) is provided, the position of the water diversion pressure regulating chamber (100) is the upstream free liquid surface position; When the tailwater surge chamber (200) is not provided, the position of the lower reservoir inlet / outlet (20A) is the downstream free liquid surface position; when the tailwater surge chamber (200) is provided, the position of the tailwater surge chamber (200) is the downstream free liquid surface position.

8. The method for calculating the feasibility of setting up underground powerhouse units and surge chambers in a pumped storage power station according to any one of claims 1 to 6, characterized in that: The calculation method of Syt is: the x-axis coordinate of the point whose y-axis coordinate is y=HL+HU in the intersection line of the first virtual plane and the terrain line of the three-dimensional terrain model is taken as Syt; The first virtual plane is a plane formed by the x-axis and the y-axis; HL is the maximum surge setting value, and HU is the normal water level of the upper reservoir (10).

9. The method for calculating the feasibility of setting up underground powerhouse units and surge chambers in a pumped storage power station according to any one of claims 1 to 6, characterized in that: The coordinate of the first intersection point on the x-axis is x=0, and the coordinate of the second intersection point on the x-axis is x=L.

10. A system for calculating the location of underground powerhouse units and surge chambers in a pumped storage power station, characterized in that: It comprises a processor, which is configured to execute the steps of the method for calculating the feasibility of setting up underground powerhouse units and surge chambers in a pumped-storage power station according to any one of claims 1-9.

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