A stable voltage system of closed cycle technology water supply for a multi-silt hydropower station

Abstract

The application relates to a kind of stable voltage systems of closed cycle technology water supply of high-sediment hydropower station, and belongs to the technical field of hydroelectric power generation, in order to solve the problem of insufficient stable voltage measures of closed cycle technology water supply of high-sediment hydropower station, the stable voltage system comprises a stable voltage water tank, a stable voltage pump and a pressure relief valve; the stable voltage water tank is communicated with one end of a pressure control pipeline through a booster pipeline and a pressure relief pipeline, the other end of the pressure control pipeline is communicated with a closed cycle system, a stable voltage pump, a flow regulating valve and a first check valve are arranged on the booster pipeline, a pressure relief valve is arranged on the pressure relief pipeline, a pressure transmitter, a low pressure switch and a high pressure switch are arranged on the pressure control pipeline; a first check valve and a stable voltage pump are arranged on the booster pipeline, water in the closed cycle system cannot flow from the booster pipeline to the stable voltage water tank, so the stable voltage water tank can be arranged at the same elevation of the technical water supply system equipment, which is convenient for centralized management of the equipment, and overflow phenomenon does not occur.

Description

Technical Field

[0001] This invention belongs to the field of hydropower technology, and in particular relates to a pressure stabilization system for closed-loop water supply technology in hydropower stations with high sediment content. Background Technology

[0002] For hydropower stations with a head of over 700 meters and high sediment content, the water supply pipelines and coolers are easily blocked by sediment due to the high sediment content of the rivers. Therefore, a combination of open and closed circulation systems is generally used for water supply. Since thermal expansion and contraction and local leakage may occur in the closed circulation system, pressure stabilization measures are required to ensure a constant inlet pressure for each cooler user.

[0003] The commonly used pressure stabilization measures for closed-loop systems are the installation of pressure stabilizing tanks or elevated water tanks. When using a pressure stabilizing tank, as the water pressure in the circulation loop increases, circulating water flows from the makeup water branch to the pressure stabilizing tank, compressing the tank's air bladder and causing the system pressure to rise slowly, preventing excessive pressure in the circulation loop. Conversely, when the pressure in the circulation loop decreases, the pressure stabilizing tank replenishes water to prevent a sharp drop in system pressure. Alternatively, an elevated water tank can be used for pressure stabilization. The elevated water tank automatically replenishes or fills the loop according to pressure changes in the circulation system, maintaining stable pressure in the closed-loop system.

[0004] Both of the above methods have certain drawbacks. When using a pressure stabilizing tank for pressure stabilization, the pressure stabilizing tank is a pressure vessel, and its design, manufacturing, and construction must meet the relevant specifications for pressure vessels. The equipment cost and manufacturing and construction difficulty are greater than those of an elevated water tank. Furthermore, the water pressure in the closed system will change with the changes in the pressure bladder of the pressure stabilizing tank. If the amount of water flowing into and out of the pressure stabilizing tank is too large, it will cause drastic changes in the water pressure of the closed circulation system, which is not conducive to the stability of the pressure at the user inlet of the closed circulation system. In addition, since the pressure stabilizing tank is a pressurized device, there are certain safety hazards during operation. When using an elevated water tank for pressure stabilization, in order to ensure the water pressure requirements of each cooler user inlet (statistics show that the inlet water pressure of the unit coolers is mostly between 0.4 and 0.8 MPa), the water tank will be located at a higher position than the cooler equipment itself. If the power station is an underground power station, it is difficult to find a suitable location for the elevated water tank. Furthermore, regardless of whether it is an above-ground power station or an underground power station, the location of the high-level water tank is far from the closed-loop system, which increases the difficulty of pipeline laying and is not conducive to centralized management of the equipment. Therefore, a new closed-loop system pressure stabilization method is needed to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a pressure stabilization system for closed-loop water supply in high-head, high-sediment hydropower stations. This addresses the shortcomings of traditional pressure stabilization measures, such as installing pressure stabilizing tanks or elevated water tanks, in closed-loop water supply systems for high-head, high-sediment hydropower stations. The technical solution adopted in this invention is as follows:

[0006] A pressure stabilizing system for closed-loop water supply in a hydropower station with high sediment content includes a pressure stabilizing tank, a pressure stabilizing pump, a pressure relief valve, and a pressure transmitter. The pressure stabilizing tank is connected to one end of a pressure control pipeline via a booster pipeline and a pressure relief pipeline, respectively. The other end of the pressure control pipeline is connected to the closed-loop system. The booster pipeline is equipped with a pressure stabilizing pump, a flow regulating valve, and a first check valve in sequence along the water flow direction. The pressure relief pipeline is equipped with a pressure relief valve. The pressure control pipeline is equipped with a pressure transmitter, a low-level pressure switch, and a high-level pressure switch. The clean water system is connected to the pressure stabilizing tank via a main water supply pipeline.

[0007] When the pressure in the closed-loop system drops to the set value of the pressure transmitter and the low-level pressure switch, the low-level pressure switch outputs a signal to control the pressure stabilizing pump to start, and the pressure stabilizing water tank replenishes water and pressurizes the closed-loop system through the booster pipeline; when the pressure in the closed-loop system rises to the set value of the high-level pressure switch, the pressure stabilizing pump shuts down.

[0008] When the pressure in the closed-loop system rises to the set pressure of the pressure relief valve, the closed-loop system drains water into the pressure stabilizing tank through the pressure relief pipeline to relieve pressure. The reseating pressure of the pressure relief valve is equal to the set value of the high-level pressure switch.

[0009] Furthermore, the main water supply pipe is equipped with a fourth check valve and an electric ball valve in sequence along the water flow direction, and the pressure stabilizing water tank is equipped with a first liquid level switch, a second liquid level switch, a third liquid level switch and a fourth liquid level switch in sequence from high to low.

[0010] When the water level in the pressure-stabilizing water tank drops to the position of the third liquid level switch, the electric ball valve opens, and the main water supply pipe replenishes water to the pressure-stabilizing water tank.

[0011] When the water level in the pressure-stabilizing water tank rises to the position of the second liquid level switch, the electric ball valve closes and water replenishment stops.

[0012] When the water level in the pressure-stabilizing water tank drops to the position of the fourth level switch, the fourth level switch issues a low water level alarm signal.

[0013] When the water level in the pressure-stabilizing water tank rises to the position of the first liquid level switch, the first liquid level switch issues a high water level alarm signal.

[0014] Furthermore, a ball valve is provided at the inlet end of the fourth check valve.

[0015] Furthermore, the open circulation system is connected to the inlet of the hydrocyclone through a backup water supply pipeline. The overflow port of the hydrocyclone is connected to the main water supply pipeline through a clear water branch pipe located between the fourth check valve and the electric ball valve. A second check valve is installed on the clear water branch pipe. The sedimentation port of the hydrocyclone is connected to the tailwater pipe through a sediment water branch pipe. A third check valve is installed on the sediment water branch pipe.

[0016] Furthermore, ball valves are installed on the backup water supply pipeline, the clean water branch pipeline, and the silt water branch pipeline.

[0017] Furthermore, the top of the pressure-stabilizing water tank is provided with an overflow port, which is connected to the water collection well of the hydropower station through an overflow pipe, and the overflow port is higher than the first liquid level switch.

[0018] Furthermore, the bottom of the pressure-stabilizing water tank is provided with a drain outlet, which is connected to the water collection well of the hydropower station through a drain pipe, and a fourth ball valve is provided on the drain pipe.

[0019] Furthermore, a ball valve is installed on the inlet pipe of the pressure stabilizing pump, and a ball valve is installed on the outlet pipe of the first check valve.

[0020] Furthermore, ball valves are installed on both ends of the pressure relief valve.

[0021] Furthermore, the top of the pressure-stabilizing water tank is equipped with a pressure-balancing bend, which connects the inside of the pressure-stabilizing water tank to the outside atmosphere.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] 1. The connection between a conventional elevated water tank and the closed-loop technical water supply system follows the principle of communicating vessels. To maintain the required water pressure at the inlet of the main transformer cooler group, the elevated water tank is typically located at a higher position. This invention solves the problem of the pressure-stabilizing water tank having to be located at a higher position by installing a first one-way valve and a pressure-stabilizing pump between the pressure-stabilizing water tank and the closed-loop system. Due to the first one-way valve, water in the closed-loop system cannot flow from the booster pipe to the pressure-stabilizing water tank. Therefore, the pressure-stabilizing water tank can be located at the same elevation as the technical water supply system equipment, facilitating centralized equipment management and preventing overflow.

[0024] 2. Conventional high-level water tanks typically use clean water systems for makeup water. Since closed-loop systems are crucial for the stable operation of technical water supply systems, this invention introduces a water source from an open-loop system into the makeup water pipe of the pressure-stabilizing water tank. Furthermore, automatic switching of the water source is achieved through pressure adjustment to ensure the stability and reliability of the system. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the present invention;

[0026] Figure 2 This is a schematic diagram of the technical water supply system of a high-head, high-silt hydropower station;

[0027] Figure 3 This is the system diagram of the main transformer cooler group;

[0028] Figure 4 This is a system diagram of the air cooler assembly;

[0029] Figure 5 This is a system diagram of a plate heat exchanger assembly;

[0030] Figure 6 This is a system diagram of the circulating pump set;

[0031] Figure 7 This is a system diagram of the pressure filtration equipment and the tailwater pipe section.

[0032] In the diagram: 1-Pressure stabilizing water tank, 11-Pressure balancing bend, 12-Overflow pipe, 13-Drain pipe, 14-First level switch, 15-Second level switch, 16-Third level switch, 17-Fourth level switch, 2-Pressure relief pipeline, 21-Pressure relief valve, 3-Boosting pipeline, 31-Pressure stabilizing pump, 32-Flow regulating valve, 33-First check valve, 4-Pressure control pipeline, 41-Pressure transmitter, 42-Low-level pressure switch, 43-High-level pressure switch, 5-Hydrocyclone, 51-Clear water branch pipe, 52- Second check valve, 53-Sediment water branch pipe, 54-Third check valve, 55-Backup water supply pipe, 6-Main water supply pipe, 61-Fourth check valve, 62-Electric ball valve, 7-Closed circulation system, 71-First parallel branch, 72-Second parallel branch, 73-Third parallel branch, 74-Fourth parallel branch, 75-Fifth parallel branch, 76-Sixth parallel branch, 77-Thermometer group, 78-Circulation pump group, 8-Open circulation system, 81-Pressure filtration equipment, 82-Tailwater pipe, 9-Plate heat exchanger group. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the invention is described below with reference to specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0034] The connections mentioned in this invention are divided into fixed connections and detachable connections. Fixed connections, also known as non-detachable connections, include but are not limited to conventional fixed connection methods such as folded connections, riveted connections, adhesive connections, and welded connections. Detachable connections include but are not limited to conventional disassembly methods such as bolted connections, snap-fit ​​connections, pin connections, and hinged connections. When a specific connection method is not explicitly defined, it is assumed that at least one existing connection method can be found to achieve this function, and those skilled in the art can choose according to their needs. For example, a welded connection can be chosen for fixed connections, and a bolted connection can be chosen for detachable connections.

[0035] The present invention will be further described in detail below with reference to the accompanying drawings. The following embodiments are explanations of the present invention, but the present invention is not limited to the following embodiments.

[0036] Examples, such as Figure 1-7 As shown:

[0037] The combined open and closed-loop water supply system comprises two subsystems: an open-loop system 8 and a closed-loop system 7. The open-loop system 8 provides a cooling source for the closed-loop system 7, and the two systems exchange heat through a plate heat exchanger assembly 9. The open-loop system 8 draws water from the tailrace pipe 82, processes it through a pressure filter 81, and then enters the plate heat exchanger assembly 9 to provide a cooling source for the closed-loop system 7. After heat exchange, the hot water is discharged back into the tailrace pipe 82. The closed-loop system 7 is powered by a circulating pump assembly 78 to offset the hydraulic losses throughout the system. After heat exchange through the plate heat exchanger assembly 9, the pump cools the main transformer cooler assembly, air cooler assembly, upper guide bearing, lower guide bearing, inlet valve hydraulic device, and governor hydraulic device.

[0038] The high-temperature flow path of the circulating pump group 78 and the plate heat exchanger group 9, along with the parallel pipeline group, are connected end-to-end to form a closed-loop system 7. The first parallel branch 71, the second parallel branch 72, the third parallel branch 73, the fourth parallel branch 74, the fifth parallel branch 75, and the sixth parallel branch 76 are connected in parallel to form a parallel pipeline group. Along the water flow direction, the first parallel branch 71 is equipped with a ball valve, a main transformer cooler, a flow meter, a flow control valve, and a check valve in sequence. Along the water flow direction, the second parallel branch 72 is equipped with a ball valve, a pressure gauge, a resistance thermometer, an upper guide bearing cooler, a flow meter, a resistance thermometer, a pressure gauge, a flow control valve, a ball valve, and a check valve in sequence. Along the water flow direction, the third parallel branch 73 is equipped with... The fourth parallel branch 74 is equipped with a ball valve, air cooler, flow meter, flow control valve, ball valve, and check valve in sequence along the water flow direction. The fifth parallel branch 75 is equipped with a ball valve, pressure gauge, resistance thermometer, solenoid directional valve, inlet valve oil pressure device cooler, pressure switch, resistance thermometer, pressure gauge, ball valve, and check valve in sequence along the water flow direction. The sixth parallel branch 76 is equipped with a ball valve, pressure gauge, resistance thermometer, solenoid directional valve, speed controller oil pressure device cooler, pressure switch, resistance thermometer, pressure gauge, ball valve, and check valve in sequence along the water flow direction.

[0039] The clean water outlet of the pressure filter 81 is connected to the low-temperature process inlet of the plate heat exchanger group 9. The low-temperature process outlet of the plate heat exchanger group 9 is connected to the tailwater pipe 82. The tailwater pipe 82 is connected to the inlet of the pressure filter. The drain outlet of the pressure filter 81 is connected to the tailwater pipe 82. The pressure filter 81, the tailwater pipe 82 and the low-temperature process of the plate heat exchanger group 9 constitute an open circulation system 8.

[0040] A pressure stabilization system for closed-loop water supply in a hydropower station with high sediment content includes a pressure stabilization tank 1, a pressure stabilization pump 31, a pressure relief valve 21, and a pressure transmitter 41. The pressure stabilization tank 1 is connected to one end of a pressure control pipeline 4 via a booster pipeline 3 and a pressure relief pipeline 2. The other end of the pressure control pipeline 4 is connected to the inlet of the circulation pump group 78 of the closed-loop system 7. Water in the booster pipeline 3 flows from the pressure stabilization tank 1 to the pressure control pipeline 4, and water in the pressure relief pipeline 2 flows from the pressure control pipeline 4 to the pressure stabilization tank 1. The booster pipeline 3 is equipped with a pressure stabilization pump 31, a flow regulating valve 32, and a first check valve 33 in sequence along the water flow direction. The pressure relief pipeline 2 is equipped with a pressure relief valve 21. The pressure control pipeline 4 is equipped with a pressure transmitter 41, a low-level pressure switch 42, and a high-level pressure switch 43. The clean water system is connected to the pressure stabilization tank 1 via a main water supply pipe 6.

[0041] To prevent pump malfunction, when the pressure in the closed-loop system 7 drops to the set value of 0.48 MPa of the pressure transmitter 41 and the low-level pressure switch 42, the low-level pressure switch 42 outputs a signal to control the pressure stabilizing pump 31 to start. The pressure stabilizing water tank 1 replenishes water and pressurizes the closed-loop system 7 through the booster pipeline 3, and the flow regulating valve 32 is used to adjust the water replenishment time. When the pressure in the closed-loop system 7 rises to the set value of 0.5 MPa of the high-level pressure switch 43, the pressure stabilizing pump 31 shuts down, and the water in the booster pipeline 3 stops flowing.

[0042] When the pressure in the closed-loop system 7 rises to the set pressure of the pressure relief valve 21 (0.53 MPa), the closed-loop system 7 drains water and releases pressure to the pressure stabilizing water tank 1 through the pressure relief pipeline 2. The reseating pressure of the pressure relief valve 21 is equal to the set value of the high-level pressure switch 43.

[0043] The connection between a conventional elevated water tank and the closed-loop technical water supply system follows the principle of communicating vessels. To maintain the required water pressure at the inlet of the main transformer cooler group, the elevated water tank is typically located at a higher position. This invention solves the problem of the pressure-stabilizing water tank 1 having to be positioned at a higher level by installing a first one-way valve 33 and a pressure-stabilizing pump 31 between the pressure-stabilizing water tank 1 and the closed-loop system 7. Due to the installation of the first one-way valve 33, water in the closed-loop system 7 cannot flow from the booster pipe 3 to the pressure-stabilizing water tank 1. Therefore, the pressure-stabilizing water tank 1 can be located at the same elevation as the technical water supply system equipment, facilitating centralized equipment management and preventing overflow. The head selection of the pressure stabilizing pump 31 needs to consider the elevation of the main transformer cooler group, the inlet pressure of the cooler, the head of the circulating pump group 78, the friction distance from the inlet of the main transformer cooler group to the pressure stabilizing water tank 1, and local head losses. The rated flow rate of the pressure stabilizing pump 31 can be determined based on the pipe diameter of the water supply pipe and the economic flow velocity (1~3m / s). The water supply pipe mentioned here refers to the booster pipe 3 and the pressure control pipe 4. The pressure control pipe 4 is equipped with a pressure transmitter 41, a low-level pressure switch 42, and a high-level pressure switch 43. The start and stop of the pressure stabilizing pump 31 are controlled by the set values ​​of the low-level pressure switch 42 and the high-level pressure switch 43. The start and stop of the pressure stabilizing pump 31 are only for the condition of pressure drop in the closed-loop system 7. If the pressure of the closed-loop system 7 rises and reaches the set pressure of the pressure relief valve 21, the closed-loop system 7 drains water to the pressure stabilizing water tank 1 through the pressure relief pipe 2 to relieve pressure and prevent the pressure of the closed-loop system 7 from rising excessively.

[0044] The main water supply pipe 6 is equipped with a fourth check valve 61 and an electric ball valve 62 in sequence along the water flow direction. The pressure stabilizing water tank 1 is equipped with a first liquid level switch 14, a second liquid level switch 15, a third liquid level switch 16 and a fourth liquid level switch 17 in sequence from high to low.

[0045] When the water level in the pressure-stabilizing water tank 1 drops to the position of the third liquid level switch 16, the electric ball valve 62 opens, and the main water supply pipe 6 supplies water to the pressure-stabilizing water tank 1.

[0046] When the water level in the pressure-stabilizing water tank 1 rises to the position of the second liquid level switch 15, the electric ball valve 62 is shut off, and water replenishment stops.

[0047] When the water level in the pressure-stabilizing water tank 1 drops to the position of the fourth liquid level switch 17, the fourth liquid level switch 17 issues a low water level alarm signal.

[0048] When the water level in the pressure-stabilizing water tank 1 rises to the position of the first liquid level switch 14, the first liquid level switch 14 issues a high water level alarm signal.

[0049] The inlet end of the fourth check valve 61 is equipped with a ball valve.

[0050] In the open circulation system 8, the pipeline located on the low-temperature process inlet side of the plate heat exchanger group 9 is connected to the inlet of the hydrocyclone 5 through the spare water supply pipeline 55. The overflow port of the hydrocyclone 5 is connected to the section of the main water supply pipe 6 located between the fourth check valve 61 and the electric ball valve 62 through the clear water branch pipe 51. The clear water branch pipe 51 is equipped with a second check valve 52. The sedimentation port of the hydrocyclone 5 is connected to the tailwater pipe 82 through the sediment water branch pipe 53. The sediment water branch pipe 53 is equipped with a third check valve 54.

[0051] Ball valves are installed on the backup water supply pipe 55, the clean water branch pipe 51, and the muddy water branch pipe 53.

[0052] The conventional high-level water tank replenishment water source is generally from the clean water system. Since the closed-loop circulation system 7 is crucial for the stable operation of the technical water supply system, this invention also draws a water source from the open circulation system 8 to the replenishment pipe of the pressure stabilizing water tank 1, and realizes automatic switching of the water source through pressure setting to ensure the stability and reliability of the system. The replenishment pipe mentioned here is the pipeline composed of the backup replenishment pipe 55 and the clean water branch pipe 51. The pressure filtration device 81 is insufficient to filter the muddy water in the tailwater pipe 82 into clean water. The hydrocyclone 5 filters the replenishment water delivered by the open circulation system 8 through the backup replenishment pipe 55. The clean water enters the main replenishment pipe 6 through the clean water branch pipe 51, and the muddy water filtered by the hydrocyclone 5 returns to the tailwater pipe 82.

[0053] The pressure-stabilizing water tank 1 is provided with an overflow port at the top. The overflow port is connected to the water collection well of the hydropower station through an overflow pipe 12. The overflow port is higher than the first liquid level switch 14.

[0054] The bottom of the pressure stabilizing water tank 1 is provided with a drain outlet, which is connected to the water collection well of the hydropower station through a drain pipe 13. A fourth ball valve is provided on the drain pipe 13.

[0055] A ball valve is installed on the inlet pipe of the pressure stabilizing pump 31, and a ball valve is installed on the outlet pipe of the first check valve 33.

[0056] Ball valves are installed on both ends of the pressure relief valve 21.

[0057] The pressure stabilizing water tank 1 is equipped with a pressure balancing bend 11 at the top, which connects the inside of the pressure stabilizing water tank 1 to the outside atmosphere.

[0058] The above embodiments are merely illustrative examples of this patent and do not limit its scope of protection. Those skilled in the art can make partial changes to them, as long as they do not exceed the spirit and essence of this patent, they are all within the scope of protection of this patent.

Claims

1. A pressure stabilization system for closed-loop water supply in a hydropower station with high sediment content, characterized in that: The system comprises a pressure stabilizing tank (1), a pressure stabilizing pump (31), a pressure relief valve (21) and a pressure transmitter (41); the pressure stabilizing tank (1) is communicated with one end of a pressure control pipeline (4) through a pressurizing pipeline (3) and a pressure relief pipeline (2), the other end of the pressure control pipeline (4) is communicated with a closed circulation system (7), the pressurizing pipeline (3) is sequentially provided with the pressure stabilizing pump (31), a flow regulating valve (32) and a first check valve (33) along the water flow direction, the pressure relief pipeline (2) is provided with the pressure relief valve (21), the pressure control pipeline (4) is provided with the pressure transmitter (41), a low pressure switch (42) and a high pressure switch (43), and a clean water system is communicated with the pressure stabilizing tank (1) through a main water supplement pipeline (6); When the pressure of the closed circulation system (7) drops to the set value of the pressure transmitter (41) and the low pressure switch (42), the low pressure switch (42) outputs a signal to control the pressure stabilizing pump (31) to start, and the pressure stabilizing tank (1) supplements water to the closed circulation system (7) through the pressurizing pipeline (3) to pressurize; When the pressure of the closed circulation system (7) rises to the set value of the high pressure switch (43), the pressure stabilizing pump (31) is stopped; When the pressure of the closed circulation system (7) rises to the set pressure of the pressure relief valve (21), the closed circulation system (7) discharges water to the pressure stabilizing tank (1) through the pressure relief pipeline (2) to relieve pressure, and the reset pressure of the pressure relief valve (21) is equal to the set value of the high pressure switch (43); 2. The stable voltage system of a closed cycle technology water supply of a multi-sediment hydropower station according to claim 1, characterized in that: An open circulation system (8) is communicated with an inlet of a hydrocyclone (5) through a standby water supplement pipeline (55), an overflow outlet of the hydrocyclone (5) is communicated with a pipe section of the main water supplement pipeline (6) between a fourth check valve (61) and an electric ball valve (62) through a clean water branch pipeline (51), the clean water branch pipeline (51) is provided with a second check valve (52), a desilting inlet of the hydrocyclone (5) is communicated with a tailrace pipe (82) through a silt water branch pipeline (53), and the silt water branch pipeline (53) is provided with a third check valve (54). The main water supplement pipeline (6) is sequentially provided with the fourth check valve (61) and the electric ball valve (62) along the water flow direction, and the pressure stabilizing tank (1) is sequentially provided with a first liquid level switch (14), a second liquid level switch (15), a third liquid level switch (16) and a fourth liquid level switch (17) from high to low; When the water level in the pressure stabilizing tank (1) drops to the position of the third liquid level switch (16), the electric ball valve (62) is opened, and the main water supplement pipeline (6) supplements water to the pressure stabilizing tank (1); When the water level in the pressure stabilizing tank (1) rises to the position of the second liquid level switch (15), the electric ball valve (62) is stopped, and the water supplement is stopped; When the water level in the pressure stabilizing tank (1) drops to the position of the fourth liquid level switch (17), the fourth liquid level switch (17) sends a low water level alarm signal; 3. The stable voltage system of a closed cycle technology water supply of a multi-sediment hydropower station according to claim 2, characterized in that: When the water level in the pressure stabilizing tank (1) rises to the position of the first liquid level switch (14), the first liquid level switch (14) sends a high water level alarm signal. The inlet end of the fourth check valve (61) is provided with a ball valve.

4. The stable voltage system of a closed cycle technology water supply of a multi-sediment hydropower station according to claim 1, characterized in that: Ball valves are arranged on the standby water supplement pipeline (55), the clean water branch pipeline (51) and the silt water branch pipeline (53) respectively.

5. The stable voltage system of a closed cycle technology water supply of a multi-sediment hydropower station according to claim 1, characterized in that: An overflow port is arranged on the top of the pressure stabilizing tank (1), the overflow port is communicated with the water collecting well of the hydropower station through an overflow pipe (12), and the overflow port is higher than the fourth liquid level switch (17).

6. The stable voltage system of a closed cycle technology water supply of a multi-sediment hydropower station according to claim 1, characterized in that: A drain port is arranged on the bottom of the pressure stabilizing tank (1), the drain port is communicated with the water collecting well of the hydropower station through a drain pipe (13), and the fourth ball valve is arranged on the drain pipe (13).

7. The stable voltage system of a closed cycle technology water supply of a multi-sediment hydropower station according to claim 1, characterized in that: Ball valves are arranged on the inlet pipeline of the pressure stabilizing pump (31) and the outlet pipeline of the first one-way valve (33).

8. The stable voltage system of a closed cycle technology water supply of a multi-sediment hydropower station according to claim 1, characterized in that: Ball valves are arranged on the pipelines at both ends of the pressure relief valve (21).

9. The stable voltage system of a closed cycle technology water supply of a multi-sediment hydropower station according to any one of claims 1-8, characterized in that: A pressure balance elbow (11) is arranged on the top of the pressure stabilizing tank (1), and the pressure balance elbow (11) communicates the inside of the pressure stabilizing tank (1) with the outside atmosphere.

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