A power generation and supply system based on reconstruction of existing water conservancy projects and a construction method thereof

Abstract

A power generation and supply system based on reconstruction of existing water conservancy projects and a construction method thereof, the power generation and supply system comprising an existing reservoir, a concrete water retaining dam arranged on the existing reservoir, and an existing diversion tunnel arranged on the existing reservoir; further comprising a power generation system and a power supply system connected with each other; the existing diversion tunnel comprises a diversion tunnel front section, a diversion tunnel middle section and a diversion tunnel rear section in sequence along a water flow direction; the power generation system comprises an underground powerhouse, a power generation device arranged in the underground powerhouse, and the underground powerhouse is connected with the diversion tunnel front section through a first inclined shaft; the underground powerhouse is connected with the diversion tunnel rear section through a second inclined shaft. The power generation system provided by the application fully utilizes the existing reservoir as a storage system, and the existing diversion tunnel as a diversion system and a ventilation and safety tunnel, so that limited resources are fully utilized, and the investment cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of water conservancy and hydropower engineering technology, and in particular to a power generation and supply system based on the reconstruction of existing water conservancy projects and its construction method. Background Technology

[0002] In recent years, my country's water conservancy and hydropower projects have been constructed rapidly, solving the needs of farmland irrigation and residential water use. However, these traditional water conservancy projects can no longer compensate for my country's energy shortage. Figure 1 As shown, existing water conservancy engineering structures often include existing reservoirs 101, concrete dams 102 installed on existing reservoirs 101, and existing diversion tunnels installed on existing reservoirs 101. How to utilize existing reservoirs 101 and diversion tunnels in existing water conservancy engineering structures to solve peak electricity demand for residents or industries near the reservoir and make up for insufficient energy consumption is an urgent problem to be solved. Summary of the Invention

[0003] The main objective of this invention is to propose a power generation and supply system based on the reconstruction of existing water conservancy projects and its construction method, which utilizes existing reservoirs and diversion tunnels in the existing water conservancy project structure to solve the peak electricity demand of residents or industries near the reservoir and fill the energy shortage.

[0004] To achieve the above objectives, on the one hand, this invention proposes a power generation and supply system based on the reconstruction of an existing water conservancy project, including an existing reservoir, a concrete dam set on the existing reservoir, and an existing diversion tunnel set on the existing reservoir; it also includes a power generation system and a power supply system connected to each other; the existing diversion tunnel includes, in sequence along the water flow direction, a front section, a middle section, and a rear section; the power generation system includes an underground powerhouse, in which power generation equipment is installed, and the underground powerhouse is connected to the front section of the diversion tunnel through a first inclined shaft; the underground powerhouse is connected to the rear section of the diversion tunnel through a second inclined shaft.

[0005] Preferably, the power supply system includes a substation system, a distribution system, and an energy storage system; the substation system is connected to the power generation equipment in the power generation system to convert high-voltage electricity into safe voltage; the distribution system is connected to the substation system to distribute the electricity required by residents or industrial areas; and the energy storage system is connected to both the substation system and the distribution system to store excess electricity in both systems.

[0006] Preferably, a first control system and a second control system are provided between the distribution system and the energy storage system; the first control system is used to control the power of the distribution system and transfer excess power to the energy storage system for storage, and the second control system is used to control the energy storage system to supplement the power of the distribution system during peak power consumption.

[0007] Preferably, the energy storage system supplies power directly to residential or industrial areas through a second control system.

[0008] Preferably, the angle between the first inclined shaft and the horizontal direction is θ, and 55°≤θ≤60°, and the cross-sectional shape and size of the first inclined shaft are the same as those of the front section of the diversion tunnel.

[0009] Preferably, the angle between the second inclined shaft and the horizontal direction is β, and 55°≤β≤60°, and the cross-sectional shape and size of the second inclined shaft are the same as those of the rear section of the diversion tunnel.

[0010] Preferably, a tailrace tunnel is connected to the underground powerhouse, and the tailrace tunnel has a circular cross-section; an access tunnel is provided on the underground powerhouse.

[0011] Preferably, an exhaust and power transmission tunnel is connected to the underground plant, and an exhaust and power transmission shaft is connected to the exhaust and power transmission tunnel; power transmission lines are installed inside the exhaust and power transmission tunnel and the exhaust and power transmission shaft to connect the power generation equipment and the substation system, and the exhaust and power transmission tunnel and the exhaust and power transmission shaft form an exhaust structure.

[0012] On the other hand, the present invention also provides a construction method for the above-mentioned power generation and supply system based on the reconstruction of existing water conservancy projects, comprising the following steps:

[0013] Step S1: Based on the location of the existing reservoir and the structure of the front section, middle section and rear section of the existing diversion tunnel, determine the location of the underground powerhouse, the first inclined shaft and the second inclined shaft. The front section of the diversion tunnel and the first inclined shaft form a water diversion tunnel, and the rear section of the diversion tunnel and the second inclined shaft form a ventilation and safety tunnel.

[0014] Step S2: Using the front and rear sections of the diversion tunnel as slag discharge channels, excavate the first and second inclined shafts, and carry out shotcrete support and secondary lining construction.

[0015] Step S3: Carry out the tailrace tunnel and access tunnel construction respectively, and carry out shotcrete support and secondary lining construction.

[0016] Step S4: Excavate the ventilation and power transmission shaft and the ventilation and power transmission tunnel, construct the initial support and secondary lining, and reserve space for the transmission line;

[0017] Step S5: Excavate the underground powerhouse tunnel, carry out initial support and secondary lining, and implement seepage prevention measures.

[0018] Step S6: Install drainage pipes and generator sets on the underground plant and connect them to the external power supply system.

[0019] Preferably, the middle section of the existing diversion tunnel is kept unobstructed, which can be used as a maintenance channel or as a mechanical storage compartment.

[0020] Due to the adoption of the above technical solution, the beneficial effects of the present invention are as follows:

[0021] First, the power generation system provided by this invention makes full use of existing reservoirs as storage systems and existing diversion tunnels as water diversion systems and ventilation and safety tunnels, making full use of limited resources and reducing investment costs.

[0022] Second: The newly built water conveyance tunnel and safety ventilation tunnel are connected to the underground powerhouse through inclined shafts, which can effectively adapt to the terrain, ensure the potential energy difference between the underground powerhouse and the existing reservoir, facilitate ventilation, and also facilitate power generation in the underground powerhouse.

[0023] Third: The ventilation tunnel also serves as a passageway for ventilation and power transmission lines. This effectively follows the principle of "fewer tunnels, more integration," fully utilizes the advantages of the terrain and existing conditions, solves the problem of power transmission on the one hand, reduces the cost of power transmission on the other hand, and can improve the construction progress.

[0024] Fourth: The underground power plant generates electricity from the substation and converts it into power for nearby residents or industries. It is equipped with an energy storage system and a distribution system. The energy storage system stores excess electricity to solve peak electricity demand, while the distribution system solves the problem of electricity distribution. The energy storage system and the distribution system complement each other.

[0025] Fifth: This invention can convert existing water conservancy projects into power generation and supply structures, making full use of existing reservoirs as storage systems and existing diversion tunnels as water diversion systems and ventilation and safety tunnels. It makes full use of limited resources, and the newly built diversion tunnel and safety ventilation tunnel are connected to the underground powerhouse through inclined shafts, which can effectively adapt to the terrain, ensure the potential energy difference between the underground powerhouse and the existing reservoir, facilitate ventilation, and also facilitate power generation in the underground powerhouse. The exhaust tunnel also serves as an exhaust and transmission line channel. This effectively follows the principle of "fewer tunnels, more integration", giving full play to the advantages of the terrain and existing conditions. On the one hand, it solves the problem of power transmission, on the other hand, it reduces the cost of power transmission and can improve the construction progress. In addition, the power generation in the underground powerhouse is converted into power supply for nearby residents or industries by a substation. It is equipped with an energy storage system and a distribution system. The energy storage system stores excess electricity to solve peak power demand, and the distribution system solves the problem of power distribution. The energy storage system and the distribution system complement each other. The overall system layout and construction are relatively conventional, without involving high-difficulty construction. Existing technologies can be used to solve all problems, and construction can be carried out simultaneously between different chambers without causing construction collisions. The construction is relatively flexible and highly operable. It makes full use of existing resources, integrates energy, saves investment, and solves the peak electricity demand problem for residents or industrial areas. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the overall layout of the power generation and supply system based on the reconstruction of existing water conservancy projects provided by the present invention;

[0028] Figure 2 This is a schematic diagram showing the spatial relationship between the underground powerhouse and the existing diversion tunnel, the first inclined shaft, and the second inclined shaft in this invention;

[0029] Figure 3 This is a schematic diagram of the electricity consumption process in residential or industrial areas according to the present invention;

[0030] Figure 4 yes Figure 2 Detailed schematic diagram of interface A;

[0031] Figure 5 yes Figure 2 Detailed schematic diagram of interface B;

[0032] Figure 6 This invention provides a construction method and process for a power generation and supply system based on the reconstruction of existing water conservancy projects.

[0033] Explanation of reference numerals: 1. Existing System; 101. Existing Reservoir; 102. Concrete Dam; 103. Front Section of Diversion Tunnel; 104. Middle Section of Diversion Tunnel; 105. Rear Section of Diversion Tunnel; 2. Power Generation System; 201. First Inclined Shaft; 202. Second Inclined Shaft; 203. Underground Powerhouse; 204. Tailrace Tunnel; 205. Access Tunnel; 206. Ventilation and Power Transmission Shaft; 207. Ventilation and Power Transmission Tunnel; 208. Pressure Steel Pipe; 209. Ventilation duct; 3. Power supply system; 301. Substation system; 302. Distribution system; 303. Energy storage system; 304. First control system; 305. Second control system; 4. First transmission line; 5. Second transmission line; 6. Third transmission line; 7. Fourth transmission line; 8. Fifth transmission line; 9. Sixth transmission line; 10. Residential or industrial area; 11. Branch ditch or gully; 12. Downstream area; 13. Ridgeline. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0035] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0036] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention. The accompanying drawings are for illustrative purposes only and do not represent defects or limitations. The dimensions of the drawings may be reduced or enlarged and do not represent actual dimensions, and the arrow "→" indicates direction and has no other practical meaning.

[0037] Combination Figures 1 to 5 As shown, a power generation and supply system based on the reconstruction of an existing water conservancy project includes an existing system 1, and interconnected power generation system 2 and power supply system 3. The existing system 1 includes an existing reservoir 101, a concrete dam 102 installed on the existing reservoir 101, and an existing diversion tunnel installed on the existing reservoir 101. The existing diversion tunnel, along the water flow direction, includes a front section 103, a middle section 104, and a rear section 105. The power generation system 2 includes an underground powerhouse 203, in which power generation equipment is installed. The underground powerhouse 203 is connected to the front section 103 of the diversion tunnel via a first inclined shaft 201; the underground powerhouse 203 is connected to the rear section 105 of the diversion tunnel via a second inclined shaft 202. The front section 103 of the diversion tunnel is part of the water diversion system, and the rear section 105 of the diversion tunnel is part of a ventilation and safety tunnel.

[0038] In this embodiment, the power supply system 3 includes a substation system 301, a distribution system 302, and an energy storage system 303. The substation system 301 is connected to the power generation equipment in the power generation system 2 to convert high-voltage electricity into safe voltage. The distribution system 302 is connected to the substation system 301 to distribute the electricity needed by residents or industrial areas 10, avoiding waste. The energy storage system 303 is connected to both the substation system 301 and the distribution system 302 to store excess electricity from both systems. A first control system 304 and a second control system 305 are provided between the distribution system 302 and the energy storage system 303. The first control system 304 controls the electricity in the distribution system 302 and transfers excess electricity to the energy storage system 303 for storage. The second control system 305 controls the energy storage system 303 to replenish the distribution system 302 during peak electricity consumption periods. The energy storage system 303 supplies power directly to the residential or industrial area 10 through the second control system 305. When the distribution system 302 fails to supply power to the residential or industrial area 10 in a timely manner, the energy storage system 303 supplies power directly to the residential or industrial area 10 through the second control system 305.

[0039] The substation system 301 is an electrical device that transforms the AC voltage across a transformer based on the principle of electromagnetic induction. It can significantly reduce energy loss on transmission lines during long-distance power transmission. Power generated by generators needs to be increased in voltage before long-distance transmission. At the load end of the transmission line, the high voltage on the line must be reduced in level before it can be used by power users.

[0040] The distribution system 302 can accept and distribute electrical energy, and is mainly composed of power distribution equipment, including busbars, high-voltage circuit breaker switches, reactor coils, transformers, power capacitors, surge arresters, high-voltage fuses, secondary equipment, and other necessary auxiliary equipment.

[0041] Energy storage system 303 uses lead-acid batteries for energy storage. Lead-acid batteries can be made into large-capacity storage systems, and have the characteristics of low unit energy cost and system cost, safety, reliability and good reusability.

[0042] The first control system 304 and the second control system 305 mainly include controllers, actuators, switches, etc., which are commonly used control systems in power systems. Their structures will not be described in detail here.

[0043] In this embodiment, the connection structure between the substation system 301, the distribution system 302, and the energy storage system 303 is as follows: Figure 1 , Figure 3As shown, the substation system 301 is connected to the power generation equipment of the underground powerhouse 203 via the first transmission line 4, and transmits electrical energy to the distribution system 302 via the third transmission line 6. It also transmits excess electrical energy to the energy storage system 303 via the second transmission line 5. The distribution system 302 distributes power to the residential or industrial area 10 via the fifth transmission line 8, and the energy storage system 303 supplies power to the residential or industrial area 10 during peak hours via the sixth transmission line 9. The distribution system 302 and the energy storage system 303 complement each other.

[0044] The substation system 301 provides a total electrical energy of U, the distribution system 302 distributes electrical energy of Q, and the energy storage system 303 stores electrical energy of M. Their relationship is as follows:

[0045] U = Q + M (1)

[0046] In equation (1): U is the total electrical energy provided by the substation system 301; Q is the electrical energy distributed by the distribution system 302; and M is the electrical energy stored by the energy storage system 303.

[0047] Substation system 301 provides the generation rate, loss rate, distribution rate, storage rate, and energy consumption rate for residential or industrial areas of total electrical energy:

[0048]

[0049] P2 = 1 - P1 (3)

[0050]

[0051]

[0052]

[0053] In equations (2) to (6): P1 is the energy availability rate; P2 is the energy loss rate; P3 is the energy allocation rate; P4 is the energy storage rate; P5 is the energy consumption rate of residential or industrial areas; R is the electricity consumption of residential or industrial areas.

[0054] Furthermore, when the power loss rate P2 = 0, the utilization rate of the total power provided by the substation system 301 is 100%.

[0055] When the electricity consumption of residents or industrial areas 10 is at its peak, the power allocated by the distribution system 302 is insufficient, and the power supply is supplemented by the energy storage system 303. At this time, Q≦R≦M+Q and P1 is close to P5. When the electricity consumption of residents or industrial areas 10 is at its low time, R<Q and P1<P5.

[0056] In this embodiment, the first inclined shaft 201 and the front section 103 of the diversion tunnel constitute a water diversion system. A pressure steel pipe 208 is installed inside the first inclined shaft 201 and the front section 103 of the diversion tunnel for water diversion. To ensure the water diversion effect of the first inclined shaft 201, the angle between the first inclined shaft 201 and the horizontal direction is θ, and 55°≤θ≤60°. When the angle is 55°≤θ≤60°, the tunnel is more stable and easier to construct. The cross-sectional shape and dimensions of the first inclined shaft 201 and the front section 103 of the diversion tunnel are the same. The second inclined shaft 202 and the rear section 105 of the diversion tunnel constitute a ventilation and safety tunnel. A ventilation duct 209 is installed inside the second inclined shaft 202 and the rear section 105 of the diversion tunnel for ventilation. To ensure the ventilation effect of the ventilation and safety tunnel, the angle between the second inclined shaft 202 and the horizontal direction is β, and 55°≤β≤60°. When the angle is 55°≤θ≤60°, the tunnel is more stable and easier to construct. The second inclined shaft 202 has the same cross-sectional shape and size as the rear section 105 of the diversion tunnel.

[0057] In this embodiment, a tailrace tunnel 204 is connected to the underground powerhouse 203. The tailrace tunnel 204 is a tunnel constructed to send the wastewater discharged from the hydropower station generator unit. The tailrace tunnel 204 has a circular cross-section, and its size can be determined according to the actual drainage volume. An access tunnel 205 is provided on the underground powerhouse 203 to facilitate the excavation of the underground powerhouse 203.

[0058] Specifically, the cross-sectional dimensions of tailrace tunnel 204 are calculated as follows:

[0059]

[0060] In the formula: Q is the discharge flow rate; μ is the flow coefficient; g is the gravitational deceleration constant; d is the tunnel diameter.

[0061] The discharge flow rate Q is mainly determined by combining the existing reservoir capacity 101 and the diversion capacity of the diversion tunnel 103.

[0062] The access tunnel (No. 205) serves multiple functions, including site access construction, factory area construction, ventilation, and subsequent maintenance. It adopts a horseshoe-shaped tunnel design, with recommended dimensions of 2.5m wide x 3m high.

[0063] In this embodiment, an exhaust and power transmission tunnel 207 is connected to the underground powerhouse 203, and an exhaust and power transmission shaft 206 is connected to the exhaust and power transmission tunnel 207. Power transmission lines are installed inside the exhaust and power transmission tunnel 207 and the exhaust and power transmission shaft 206 to connect the power generation equipment and the substation 301. The exhaust and power transmission tunnel 207 and the exhaust and power transmission shaft 206 form an exhaust structure, and their dimensions are designed according to the actual exhaust volume.

[0064] On the other hand, this embodiment also provides a construction method for the above-mentioned power generation and supply system based on the reconstruction of existing water conservancy projects, including the following steps:

[0065] Step S1: Based on the location of the existing reservoir 101 and the structure of the existing diversion tunnel front section 103, diversion tunnel middle section 104 and diversion tunnel rear section 105, determine the locations of the underground powerhouse 203, the first inclined shaft 201 and the second inclined shaft 202. The diversion tunnel front section 103 and the first inclined shaft 201 form a water diversion tunnel, and the diversion tunnel rear section 105 and the second inclined shaft 202 form a ventilation and safety tunnel.

[0066] Step S2: Using the front section 103 and the rear section 105 of the diversion tunnel as slag discharge channels, excavate the first inclined shaft 201 and the second inclined shaft 202, and carry out shotcrete support and secondary lining construction.

[0067] Step S3: Carry out the construction of tailrace tunnel 204 and access tunnel 205 respectively, and carry out shotcrete support and secondary lining construction.

[0068] Step S4: Excavate ventilation and power transmission shaft 206 and ventilation and power transmission tunnel 207, construct initial support and secondary lining, and reserve space for transmission lines;

[0069] Step S5: Excavate the underground powerhouse tunnel 203, and carry out initial support and secondary lining, and take anti-seepage measures.

[0070] Step S6: Install drainage pipes and generator sets on the underground plant 203 and connect them to the external power supply system 3.

[0071] When constructing the first inclined shaft 201, the second inclined shaft 202, the tailrace tunnel 204, the access tunnel 205, the ventilation and power transmission shaft 206, and the ventilation and power transmission tunnel 207, the principles of minimal disturbance, early support, frequent measurement, and tight sealing should be followed to ensure the safety of tunnel construction and subsequent operation.

[0072] When constructing the underground powerhouse 203, a scientific analysis should be conducted from the perspectives of technology, safety, and economic benefits, following the concept of "dynamic design" and adhering to the principle of "appropriate support".

[0073] When constructing the water diversion tunnel and the ventilation and safety tunnel, it is necessary to ensure the safety of the connection between the first inclined shaft 201 and the front section 103 of the diversion tunnel, and the second inclined shaft 202 and the rear section 105 of the diversion tunnel, so as to ensure safe construction.

[0074] After the project is completed, the middle section 104 of the existing diversion tunnel will remain unobstructed, meaning that the middle section 104 of the diversion tunnel will not need to be sealed off and can be used as a maintenance passage or a mechanical storage bin.

[0075] The principle of this invention is as follows: the first inclined shaft 201 and the front section 103 of the diversion tunnel serve as a water diversion tunnel, and the second inclined shaft 202 and the rear section 105 of the diversion tunnel serve as a ventilation and safety tunnel; the power supply system 3 includes a substation system 301, a distribution system 302, an energy storage system 303, a first control system 304, and a second control system 305. The substation system 301 converts the high-voltage electricity generated by the power generation system 2 into a safe voltage. The distribution system 302 centrally distributes the electricity required by the residents or industrial area 10 to avoid waste. The energy storage system 303 stores the excess electricity of the substation system 301 and the distribution system 302. The first control system 304 controls the electricity of the distribution system and transmits the excess electricity to the energy storage system 303 for storage. The second control system 305 supplements the distribution system 302 with electricity during peak electricity consumption. In addition, if the distribution system 302 fails to supply electricity to the residents or industrial area in a timely manner, the energy storage system 303 directly supplies electricity to the residents or industrial area through the second control system 305.

[0076] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A construction method for a power generation and supply system based on the reconstruction of an existing water conservancy project, characterized in that, The power generation and supply system includes an existing reservoir (101), a concrete dam (102) installed on the existing reservoir (101), and an existing diversion tunnel installed on the existing reservoir (101); it also includes a power generation system (2) and a power supply system (3) connected to each other; the existing diversion tunnel includes, in sequence along the water flow direction, a front section (103), a middle section (104), and a rear section (105); the power generation system (2) includes power generation equipment installed in an underground powerhouse (203), and the underground powerhouse (203) is connected to the first inclined plane. The well (201) is connected to the front section (103) of the diversion tunnel; the underground powerhouse (203) is connected to the rear section (105) of the diversion tunnel through the second inclined well (202); the first inclined well (201) has an angle of θ with the horizontal direction, and 55°≤θ≤60°, and the first inclined well (201) has the same cross-sectional shape and size as the front section (103) of the diversion tunnel; the second inclined well (202) has an angle of β with the horizontal direction, and 55°≤β≤60°, and the second inclined well (202) has the same cross-sectional shape and size as the rear section (105) of the diversion tunnel; The construction method includes the following steps: Step S1: Based on the location of the existing reservoir (101) and the structure of the existing diversion tunnel's front section (103), middle section (104), and rear section (105), determine the locations of the underground powerhouse (203), the first inclined shaft (201), and the second inclined shaft (202). The front section (103) and the first inclined shaft (201) together form a water diversion tunnel, while the rear section (105) and the second inclined shaft (202) together form a ventilation and safety tunnel. Step S2: Using the front section (103) and rear section (105) of the diversion tunnel as slag discharge channels, excavate the first inclined shaft (201) and the second inclined shaft (202), and carry out shotcrete support and secondary lining construction; Step S3: Carry out the tailrace tunnel (204) and access tunnel (205) construction respectively, and carry out shotcrete support and secondary lining construction; Step S4: Excavate the ventilation and power transmission shaft (206) and the ventilation and power transmission tunnel (207), construct the initial support and secondary lining, and reserve space for the transmission line; Step S5: Excavate the underground powerhouse (203) tunnel, carry out initial support and secondary lining, and take anti-seepage measures; Step S6: Install drainage pipes and generator sets on the underground plant (203) and connect them to the external power supply system (3).

2. The construction method for a power generation and supply system based on the reconstruction of an existing water conservancy project as described in claim 1, characterized in that: The power supply system (3) includes a substation system (301), a distribution system (302), and an energy storage system (303); the substation system (301) is connected to the power generation equipment in the power generation system (2) for converting high-voltage electricity into safe voltage; the distribution system (302) is connected to the substation system (301) for distributing the electricity required by residents or industrial areas (10); the energy storage system (303) is connected to the substation system (301) and the distribution system (302) respectively for storing the excess electricity of the substation system (301) and the distribution system (302).

3. The construction method for a power generation and supply system based on the reconstruction of an existing water conservancy project as described in claim 2, characterized in that: A first control system (304) and a second control system (305) are provided between the distribution system (302) and the energy storage system (303); the first control system (304) is used to control the power of the distribution system (302) and transfer excess power to the energy storage system (303) for storage, and the second control system (305) is used to control the energy storage system (303) to supplement the power of the distribution system (302) during peak power consumption.

4. The construction method for a power generation and supply system based on the reconstruction of an existing water conservancy project as described in claim 3, characterized in that: The energy storage system (303) supplies power directly to the residential or industrial area (10) through the second control system (305).

5. The construction method for a power generation and supply system based on the reconstruction of an existing water conservancy project as described in claim 1, characterized in that: A tailrace tunnel (204) is connected to the underground powerhouse (203), and the tailrace tunnel (204) has a circular cross-section; an access tunnel (205) is provided on the underground powerhouse (203).

6. The construction method for a power generation and supply system based on the reconstruction of an existing water conservancy project as described in claim 2, characterized in that: An exhaust and power transmission tunnel (207) is connected to the underground plant (203), and an exhaust and power transmission shaft (206) is connected to the exhaust and power transmission tunnel (207). Power transmission lines are installed inside the exhaust and power transmission tunnel (207) and the exhaust and power transmission shaft (206) to connect the power generation equipment and the substation (301). The exhaust and power transmission tunnel (207) and the exhaust and power transmission shaft (206) form an exhaust structure.

7. The construction method for a power generation and supply system based on the reconstruction of an existing water conservancy project as described in claim 1, characterized in that, The middle section (104) of the existing diversion tunnel is kept unobstructed.

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