Arrangement structure for realizing water diversion power generation at dam body opening of old dam and construction method

Abstract

The invention belongs to the technical field of water conservancy and hydropower engineering, and particularly relates to an arrangement structure for achieving water diversion power generation at an old dam body opening and a construction method. The structure comprises a water retaining dam body, a water diversion flow channel, a water diversion water inlet, a water diversion emergency gate, a water diversion pressure pipeline, outer wrapped concrete, a volute front transition section, a concrete volute and an ecological unit plant; the water diversion flow channel is located below the dead water level of an upper reservoir area and formed by transforming an opening of a water retaining dam body. The water diversion inlet is located in the rear side of the water retaining dam body and combined with the water retaining dam body. The water diversion emergency gate is located in a gate groove of the water diversion inlet. Outer wrapped concrete is arranged around the water diversion pressure pipeline; the volute front transition section is located between the tail end of the water diversion pressure pipeline and the unit concrete volute. The ecological unit plant is located on the rear side of the water retaining dam body. Water diversion power generation is achieved through the local opening of the dam body, the ecological flow discharge requirement is met, water diversion power generation is achieved, water energy resources of a river channel are fully utilized, and remarkable economic benefits are generated for the society.

Description

Technical Field

[0001] The invention belongs to the technical field of water conservancy and hydropower engineering, and specifically relates to an arrangement structure and a construction method for realizing water diversion and power generation at an opening of an old dam body. Background Art

[0002] At present, some hydropower stations built in the early stage have not set up special ecological flow discharge facilities, which in turn affects the downstream ecological base flow not meeting the standards. According to the current environmental protection requirements, it is necessary to renovate and expand the existing water conservancy projects with ecological needs and add ecological flow discharge facilities. In order to meet the requirements of releasing ecological flow and make the best use of the water resources of the river, the installation of water diversion power generation ecological units is preferred.

[0003] Conventional water diversion and power generation systems consist of water inlets, water diversion tunnels, and power plants. The water inlets are usually located inside the reservoir. Under the condition of ensuring the existing functions of the reservoir hub, the water level in the reservoir area is high and close to the normal water storage level. The water level in the reservoir cannot be lowered for a long time, which makes the design and construction of the water inlet difficult. The water diversion tunnel is arranged close to the edge of the reservoir, and water gushing may occur during the digging process, making the construction difficult. In addition, a cofferdam needs to be built inside the reservoir during the construction of the water inlet. The filling requirements of the cofferdam are high, the risk of flood control is high, and the project investment increases significantly.

[0004] Based on this, the inventor hopes to design a water diversion and power generation layout plan to solve the above problems without changing the existing functions of the reservoir hub. Summary of the invention

[0005] The purpose of the present invention is to overcome the above-mentioned problems existing in the traditional technology and to provide an arrangement structure and a construction method for realizing water diversion and power generation at the opening of the old dam body.

[0006] In order to achieve the above technical objectives and the above technical effects, the present invention is implemented through the following technical solutions:

[0007] The present invention provides a layout structure for realizing water diversion and power generation at the opening of an old dam body, comprising a water retaining dam body, a water diversion flow channel, a water diversion inlet, a water diversion emergency gate, a water diversion pressure pipe, external concrete, a front gradient section of a volute, a concrete volute and an ecological unit plant; the water diversion flow channel is located below the dead water level of the upper reservoir area, and the water diversion flow channel is transformed from the opening of the water retaining dam body serving as a hub; the water diversion inlet is located at the rear side of the water retaining dam body and is arranged in combination with the water retaining dam body; the water diversion emergency gate is located in the gate groove of the water diversion inlet; the water diversion pressure pipe is located between the water diversion inlet and the ecological unit plant, and external concrete is arranged around the pipe of the water diversion pressure pipe; the front gradient section of the volute is located between the end of the water diversion pressure pipe and the concrete volute of the unit, and the water flow flows smoothly into the concrete volute through the front gradient section of the volute; the ecological unit plant is located at the rear side of the water retaining dam body.

[0008] Furthermore, in the above-mentioned arrangement structure for realizing water diversion and power generation at the opening of the old dam body, the water diversion channel is the same length as the water retaining dam body, which is 6 to 10 meters long; the water diversion channel is a concrete lining structure.

[0009] Furthermore, in the above-mentioned arrangement structure for realizing water diversion and power generation at the opening of the old dam body, the water diversion channel is composed of a bell-mouth section and a standard section in the direction of water flow, a fixed trash rack is arranged at the front edge of the bell-mouth, the size of the bell-mouth opening meets the flow velocity requirement through the rack (V≤1m / s), and a water diversion inlet is arranged at the end of the standard section.

[0010] Furthermore, in the above-mentioned arrangement structure for realizing water diversion and power generation at the opening of the old dam body, a water-swelling waterstop strip is arranged between the water diversion channel and the concrete construction joint of the retaining dam body, a copper waterstop is arranged between the water diversion channel and the water diversion inlet structure joint, and the lining is subjected to joint grouting and the top arch range is subjected to backfill grouting.

[0011] Furthermore, in the above-mentioned arrangement structure for realizing water diversion and power generation at the opening of the old dam body, the water-stopping type of the water diversion emergency gate is a front water-stopping type that enables the water diversion inlet to withstand a smaller water pressure.

[0012] The present invention also provides a construction method for realizing water diversion and power generation at the opening of the old dam body, which is realized based on the above arrangement structure and includes the following steps:

[0013] S1. According to the design of the fully pressurized ecological discharge tunnel, determine the elevation A1 (m) of the bottom plate of the water diversion channel;

[0014] S2. Carry out foundation pit excavation, concrete pouring of ecological unit plant, installation of water diversion pressure pipeline and outsourcing concrete construction of pressure pipeline;

[0015] S3. After the outsourced concrete is poured to the elevation of the water inlet bottom plate, the water retaining dam body is partially excavated. A 2-3m concrete plug is reserved for the first-phase concrete excavation to ensure the safety of the dam during the flood season. After the flood season, the second-phase concrete excavation will be carried out on the concrete plug;

[0016] S4. After the first phase of concrete excavation is completed, the water inlet concrete pouring, the second phase of gate slot concrete pouring, and the emergency gate installation and commissioning are carried out behind the dam body to meet the reservoir water storage conditions;

[0017] S5. After the installation of the emergency gate at the water inlet is completed, the reservoir water level is lowered to below the bottom of the trash rack, and the remaining concrete plug of the dam body is excavated;

[0018] S6. After the dam is excavated and connected, the water diversion channel lining construction is carried out;

[0019] S7. Arrange water-expanding waterstop strips between the lining and the old concrete of the dam body, and arrange copper waterstop between the lining and the water inlet behind the dam to ensure good waterstop treatment;

[0020] S8. Carry out backfill grouting and joint grouting of lining and old concrete of dam body in the flow channel;

[0021] S9. A trash rack is fixedly installed on the upstream surface of the water diversion channel;

[0022] S10. After the trash rack is installed, the sluice gate is lowered to store water to the normal level, and Jinshao Power Station resumes power generation;

[0023] S11. Carry out installation work on the remaining civil engineering parts, units, and electromechanical equipment of the ecological unit.

[0024] Furthermore, in step S1, the specific method for determining the elevation A1 (m) of the water diversion channel bottom plate is:

[0025] 1) Under the conditions of the lowest operating water level H2 (m) and the maximum downstream ecological flow Q (m3 / s) in the reservoir area, the minimum submergence depth S (m) of the water inlet of the ecological flow discharge facility is determined by using the formula;

[0026] 2) According to the full pressurized flow design, determine the accident gate hole height d of the ecological flow discharge facility, the gate hole width b, and the average flow velocity (m / s) of the gate hole section;

[0027] 3) Determine the bottom plate elevation of the raw water channel A1=H2-Sd (m).

[0028] Furthermore, the coefficient C is taken as 0.55 when the water flow is symmetrical and positive, and is taken as 0.73 in other cases.

[0029] Furthermore, in step S2, since the power plant is located close to the dam, the following matters should be noted during the excavation of the power plant foundation pit:

[0030] 1) To ensure the integrity of the rock mass around the excavated foundation and the safety of adjacent buildings, hand-held pneumatic drills and shallow hole pre-splitting blasting technology are used for construction;

[0031] 2) During bedrock blasting, emphasis should be placed on strengthening the monitoring of the upstream curtain and dam body. The safe allowable blasting vibration speed of the curtain should not exceed 5.0 cm / s, and the safe allowable blasting vibration speed of the dam body concrete should not exceed 12.0 cm / s.

[0032] Furthermore, down-the-hole drills are used to excavate and remove the dam concrete. During construction, the monitoring of seepage around the dam and cracks in the dam body is strengthened. If necessary, grouting treatment is carried out on the cracks and damaged curtains.

[0033] The beneficial effects of the present invention are:

[0034] 1. For the reconstruction and expansion of water conservancy projects with ecological flow requirements, the present invention uses a partial opening of the dam body to realize water diversion and power generation, which not only meets the ecological flow discharge requirements, but also realizes water diversion and power generation, fully utilizes the water energy resources of the river, and produces significant economic benefits to the society.

[0035] 2. The present invention adopts a water diversion scheme of partial opening of the dam body and a new water inlet behind the dam, which reduces the size of the opening of the dam body as much as possible and minimizes the adverse effects on the overall structural stability and safety of the dam body; the dam body is used to block water during construction, avoiding the risk of flooding during the construction period.

[0036] 3. The construction method adopted by the present invention can reduce the reservoir water level in a short time, so the water conservancy hub can make full use of water resources and guarantee the normal power generation of the old power station to the greatest extent.

[0037] 4. The present invention has been successfully applied in actual ecological unit projects, providing rich design experience for future old dam reconstruction and ecological flow unit program research.

[0038] Of course, any product implementing the present invention does not necessarily need to achieve all of the above advantages at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0040] Figure 1 It is a schematic diagram of the structural cross section of the present invention;

[0041] Figure 2 It is a schematic structural plane diagram of the present invention. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] like Figure 1-Figure 2As shown, this embodiment provides a layout structure for realizing water diversion and power generation at the opening of the old dam body, including a water retaining dam body 1, a water diversion channel 4, a water diversion inlet 8, a water diversion emergency gate 9, a water diversion pressure pipeline 10, an outer concrete package 11, a volute front gradient section 12, a concrete volute 13 and an ecological unit plant 14.

[0044] In this embodiment, the water diversion channel 4 is located below the dead water level of the upper reservoir area, and the water diversion channel 4 is transformed from the opening of the water retaining dam body 1 serving as a hub; the water diversion inlet 8 is located at the rear side of the water retaining dam body 1 and is arranged in combination with the water retaining dam body 1; the water diversion emergency gate 9 is located in the gate groove of the water diversion inlet 8; the water diversion pressure pipe 10 is located between the water diversion inlet 8 and the ecological unit plant 14, and the water diversion pressure pipe 10 is surrounded by an outer concrete 11; the front gradient section 12 of the volute is located between the end of the water diversion pressure pipe 10 and the concrete volute 13 of the unit, and the water flow flows smoothly into the concrete volute 13 through the front gradient section 12 of the volute; the ecological unit plant 14 is located at the rear side of the water retaining dam body 1.

[0045] In this embodiment, the water diversion channel 4 is the same length as the dam body 1, which is 8 meters long; the water diversion channel 4 is a concrete lining structure. The water diversion channel 4 is divided into a bell mouth section and a standard section in the direction of water flow, and a fixed trash rack 6 is arranged at the front of the bell mouth. The size of the bell mouth orifice meets the requirements of the flow velocity through the rack (V≤1m / s), and a water diversion inlet 8 is arranged at the end of the standard section.

[0046] In this embodiment, a water-swelling waterstop strip 6 is arranged between the concrete construction joint of the water diversion channel 4 and the dam body 1, a copper waterstop 5 is arranged between the structural joint of the water diversion channel 4 and the water diversion inlet 8, and the lining is grouted for joints and the top arch range is backfilled and grouted.

[0047] In this embodiment, the water stopping type of the water diversion emergency gate 9 is front water stopping, which can make the water diversion inlet withstand smaller water pressure.

[0048] This embodiment also provides a construction method for realizing water diversion and power generation at the opening of the old dam body, comprising the following steps:

[0049] S1. According to the design of the full-pressure ecological discharge tunnel, determine the bottom plate elevation A1 (m) of the water diversion channel 4; the specific method for determining the bottom plate elevation A1 (m) of the water diversion channel is:

[0050] 1) Under the conditions of the lowest operating water level H2 (m) and the maximum downstream ecological flow Q (m3 / s) in the reservoir area, the formula S = CVd is used. 1 / 2 Determine the minimum submergence depth S (m) of the water inlet of the ecological flow discharge facility; the coefficient C is taken as 0.55 when the water flow is symmetrical and positive, and 0.73 in other cases;

[0051] 2) According to the full pressurized flow design, determine the accident gate hole height d of the ecological flow discharge facility, the gate hole width b, and the average flow velocity of the gate hole section

[0052] 3) Determine the bottom plate elevation of the raw water channel A1 = H2-Sd (m);

[0053] S2. Carry out foundation pit excavation of ecological unit plant 14, concrete pouring of ecological unit plant 14, installation of water diversion pressure pipe 10 and construction of pressure pipe outer package concrete 11. Since the power plant is located close to the water retaining dam, the following matters should be paid attention to during the foundation pit excavation of the plant:

[0054] 1) To ensure the integrity of the rock mass around the excavated foundation and the safety of adjacent buildings, hand-held pneumatic drills and shallow hole pre-splitting blasting technology are used for construction;

[0055] 2) During bedrock blasting, it is necessary to strengthen the monitoring of the upstream curtain and dam body. The curtain safety allowable blasting vibration speed should not exceed 5.0 cm / s, and the dam body concrete safety allowable blasting vibration speed should not exceed 12.0 cm / s;

[0056] S3, after the outsourced concrete 11 is poured to the bottom plate elevation of the water inlet 8, the water retaining dam body 1 is partially excavated, and a 2.5m concrete plug is reserved for the first-phase concrete excavation 2 to ensure the safety of the dam during the flood season. After the flood season, the second-phase concrete excavation 3 is carried out on the concrete plug;

[0057] S4. After the first-phase concrete excavation 2 is completed, the water inlet 8 is poured concrete behind the dam body 1, the gate slot second-phase concrete is poured, and the emergency gate 9 is installed and debugged to meet the reservoir water storage conditions;

[0058] S5. After the installation of the inlet emergency gate 9 is completed, the reservoir water level is lowered to below the bottom of the trash rack, and the remaining concrete plug of the dam body is excavated;

[0059] S6, after the water retaining dam body 1 is excavated and connected, the lining construction of the water diversion channel 4 is carried out;

[0060] S7. Arrange water-expandable waterstop strips 6 between the lining and the old concrete of the dam body, and arrange copper waterstops 5 between the lining and the water inlet behind the dam to ensure good waterstop treatment;

[0061] S8. Carry out backfill grouting and joint grouting of lining and old concrete of dam body in the flow channel;

[0062] S9, a trash rack 7 is fixedly installed on the upstream surface of the water diversion channel 4;

[0063] S10, after the trash rack 7 is installed, the gate is lowered to store water to a normal level, and the Jinshao Power Station resumes power generation;

[0064] S11. Carry out installation work on the remaining civil engineering parts, units, and electromechanical equipment of the ecological unit.

[0065] During excavation, down-the-hole drills are used to excavate and remove the dam concrete. During construction, the monitoring of seepage around the dam and cracks in the dam body is strengthened. If necessary, grouting treatment is carried out on the cracks and damaged curtains.

[0066] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A layout structure for realizing water diversion and power generation at the opening of the old dam body, It is characterized in that It includes a water retaining dam body, a water diversion channel, a water diversion inlet, a water diversion emergency gate, a water diversion pressure pipe, external concrete, a front gradient section of the volute, a concrete volute and an ecological unit plant; the water diversion channel is located below the dead water level of the upper reservoir area, and the water diversion channel is transformed from the opening of the water retaining dam body as a hub; the water diversion inlet is located at the rear side of the water retaining dam body and is arranged in combination with the water retaining dam body; the water diversion emergency gate is located in the gate groove of the water diversion inlet; the water diversion pressure pipe is located between the water diversion inlet and the ecological unit plant, and the water diversion pressure pipe is surrounded by external concrete; the front gradient section of the volute is located between the end of the water diversion pressure pipe and the concrete volute of the unit, and the water flows smoothly into the concrete volute through the front gradient section of the volute; the ecological unit plant is located at the rear side of the water retaining dam body.

2. The arrangement structure for realizing water diversion and power generation at the opening of the old dam according to claim 1, It is characterized in that The water diversion channel is as long as the dam body, which is 6 to 10 meters long; the water diversion channel is a concrete lining structure.

3. The arrangement structure for realizing water diversion and power generation at the opening of the old dam according to claim 1, It is characterized in that The water diversion channel is divided into a bell-mouth section and a standard section in the direction of water flow. A fixed trash rack is arranged at the front of the bell-mouth. The size of the bell-mouth opening meets the flow velocity requirement through the rack (V≤1m / s). A water diversion inlet is arranged at the end of the standard section.

4. The arrangement structure for realizing water diversion and power generation at the opening of the old dam according to claim 1, It is characterized in that A water-swelling waterstop strip is arranged between the water diversion channel and the concrete construction joint of the dam body, a copper waterstop is arranged between the water diversion channel and the water diversion inlet structure joint, and the lining is subjected to joint grouting and the top arch range is subjected to backfill grouting.

5. The arrangement structure for realizing water diversion and power generation at the opening of the old dam according to claim 1, It is characterized in that The water stop type of the water diversion emergency gate is a front water stop that enables the water diversion inlet to withstand a smaller water pressure.

6. A construction method for realizing water diversion and power generation at the opening of an old dam body, based on the arrangement structure according to any one of claims 1 to 5, It is characterized in that The steps include: S1. According to the design of the fully pressurized ecological discharge tunnel, determine the elevation A1 (m) of the bottom plate of the water diversion channel; S2. Carry out foundation pit excavation, concrete pouring of ecological unit plant, installation of water diversion pressure pipeline and outsourcing concrete construction of pressure pipeline; S3. After the outsourced concrete is poured to the elevation of the water inlet bottom plate, the water retaining dam body is partially excavated. A 2-3m concrete plug is reserved for the first-phase concrete excavation to ensure the safety of the dam during the flood season. After the flood season, the second-phase concrete excavation will be carried out on the concrete plug; S4. After the first phase of concrete excavation is completed, the water inlet concrete pouring, the second phase of gate slot concrete pouring, and the emergency gate installation and commissioning are carried out behind the dam body to meet the reservoir water storage conditions; S5. After the installation of the emergency gate at the water inlet is completed, the reservoir water level is lowered to below the bottom of the trash rack, and the remaining concrete plug of the dam body is excavated; S6. After the dam is excavated and connected, the water diversion channel lining construction is carried out; S7. Arrange water-expanding waterstop strips between the lining and the old concrete of the dam body, and arrange copper waterstop between the lining and the water inlet behind the dam to ensure good waterstop treatment; S8. Carry out backfill grouting and joint grouting of lining and old concrete of dam body in the flow channel; S9. A trash rack is fixedly installed on the upstream surface of the water diversion channel; S10. After the trash rack is installed, the sluice gate is lowered to store water to the normal level, and Jinshao Power Station resumes power generation; S11. Carry out installation work on the remaining civil engineering parts, units, and electromechanical equipment of the ecological unit.

7. The construction method for realizing water diversion and power generation at the opening of the old dam body according to claim 6, It is characterized in that In step S1, the specific method for determining the elevation A1 (m) of the water diversion channel bottom plate is: 1) Under the conditions of the lowest operating water level H2 (m) and the maximum downstream ecological flow Q (m3 / s) in the reservoir area, the formula S = CVd is used. 1 / 2 Determine the minimum submergence depth S (m) of the water inlet of the ecological flow discharge facility; 2) According to the full pressurized flow design, determine the accident gate hole height d of the ecological flow discharge facility, the gate hole width b, and the average flow velocity of the gate hole section 3) Determine the bottom plate elevation of the raw water channel A1=H2-Sd (m).

8. The construction method for realizing water diversion and power generation at the opening of the old dam body according to claim 7, It is characterized in that The coefficient C is 0.55 when the water flow is symmetrical and positive, and 0.73 in other cases.

9. The construction method for realizing water diversion and power generation at the opening of the old dam body according to claim 6, It is characterized in that In step S2, since the power plant is located close to the dam, the following matters should be noted during the excavation of the power plant foundation pit: 1) To ensure the integrity of the rock mass around the excavated foundation and the safety of adjacent buildings, hand-held pneumatic drills and shallow hole pre-splitting blasting technology are used for construction; 2) During bedrock blasting, emphasis should be placed on strengthening the monitoring of the upstream curtain and dam body. The safe allowable blasting vibration speed of the curtain should not exceed 5.0 cm / s, and the safe allowable blasting vibration speed of the dam body concrete should not exceed 12.0 cm / s.

10. The construction method for realizing water diversion and power generation at the opening of the old dam body according to claim 6, It is characterized in that Use down-the-hole drills to excavate and remove the dam concrete. During construction, strengthen the monitoring of seepage around the dam and cracks in the dam body. If necessary, grouting treatment is carried out on the cracks and damaged curtains.

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