Closed cycle power generation system based on tail water potential energy multistage conversion

Abstract

The embodiment of the utility model provides a closed cycle power generation system based on tail water potential energy multistage conversion, and relates to the technical field of hydroelectric power generation. The closed circulation power generation system based on tail water potential energy multi-stage conversion comprises an energy storage water tank, a lower water tank, a first flow guide pipe, a water turbine, a second flow guide pipe, a third flow guide pipe, a fourth flow guide pipe and a water-turbine generator set. Tail water stored in the lower water tank can flow into the first flow guide cavity through the first flow guide pipe and flow back to the lower water tank through the second flow guide pipe so as to drive the first impeller to rotate to drive the second impeller to rotate, and the second impeller rotates to pressurize and pump water in the lower water tank to the high-pressure water storage tank. And the water flows to the water-turbine generator set from the water outlet of the high-pressure water storage tank so as to drive the water-turbine generator set to move

Description

Technical Field

[0001] This utility model relates to the field of hydropower technology, and more specifically, to a closed-loop power generation system based on the multi-stage conversion of tailwater potential energy. Background Technology

[0002] Tailwater of a hydroelectric power station refers to the water discharged after the turbines have performed work during the hydroelectric power generation process.

[0003] In existing technologies, since the kinetic and potential energy of the tailwater is relatively small and insufficient to drive the turbine generator unit, it is generally discharged directly into the river. The energy of the tailwater will have an impact on the downstream river channel, such as scouring and siltation, and will also waste the energy in the tailwater.

[0004] Therefore, how to achieve stable energy recovery from tailwater has become a pressing technical problem to be solved in this field. Utility Model Content

[0005] The purpose of this invention is to provide a closed-loop power generation system based on the multi-stage conversion of tailwater potential energy, which can utilize the tailwater potential energy to treat the tailwater and generate electricity, thereby realizing energy reuse.

[0006] The embodiments of this utility model can be implemented as follows:

[0007] This utility model provides a closed-loop power generation system based on multi-stage conversion of tailwater potential energy, comprising:

[0008] Energy storage tanks are used to store tailwater from hydroelectric power generation.

[0009] The drainage pools are spaced apart at the bottom of the energy storage pool;

[0010] The first guide pipe, one end of which is connected to the bottom of the energy storage tank;

[0011] A water turbine includes a volute, a first impeller, and a second impeller. The volute has a first guide cavity and a second guide cavity. The first guide cavity is provided with a first inlet and a first outlet. The second guide cavity is provided with a second inlet and a second outlet. The first impeller is disposed in the first guide cavity, and the second impeller is disposed in the second guide cavity. The first impeller and the second impeller are coaxially connected.

[0012] The other end of the first guide pipe is connected to the first inlet of the water turbine, and the first outlet is connected to the second guide pipe, which is connected to the lower water tank.

[0013] The third guide pipe extends into the drain pool at one end and is connected to the second inlet at the other end;

[0014] The fourth guide pipe is connected at one end to the second outlet and at the other end to the inlet of the high-pressure water storage tank;

[0015] A hydro-turbine generator set, wherein the inlet of the hydro-turbine generator set is connected to the outlet of the high-pressure water storage tank;

[0016] The tailwater stored in the sink can flow into the first guide cavity through the first guide pipe, and then flow back to the sink through the second guide pipe to drive the first impeller to rotate and drive the second impeller to rotate. The rotation of the second impeller can pressurize the water in the sink and pump it to the high-pressure water storage tank, and then flow from the outlet of the high-pressure water storage tank to the water turbine generator set to drive the water turbine generator set to move and generate electricity.

[0017] In an optional embodiment, the first inlet and the first outlet are arranged radially opposite each other along the first impeller;

[0018] The second inlet is located axially on the second impeller, and the second outlet is located radially on the second impeller;

[0019] The third guide pipe extends from the end away from the second inlet to a position near the bottom of the sink.

[0020] In an optional embodiment, a pumping mechanism is provided in the sink, and the pumping mechanism corresponds to the outlet of the second guide pipe.

[0021] The pumping mechanism is also equipped with a fifth guide pipe that is connected to the high-pressure water storage tank;

[0022] The water flowing down the second guide pipe can drive the pumping mechanism to operate, so as to pressurize the water in the lower pool through the fifth guide pipe and pump it to the high-pressure water storage tank.

[0023] In an optional embodiment, the pumping mechanism includes a support structure, a balance bar, a water receiving tank, a main cylinder, a piston, a first check valve, and a second check valve.

[0024] The second guide pipe has multiple sets arranged in pairs, and an intermittent valve is provided at the outlet end of the second guide pipe;

[0025] The support structure is installed in the sink and is positioned at the center of the distance between the two second guide pipes in each group.

[0026] The middle part of the balance bar is rotatably connected to the support structure;

[0027] The balance bar is provided with a water receiving trough at the outlet position of each of the two second guide pipes in each group;

[0028] The main cylinder is provided on both sides of the support structure at intervals. The main cylinder has a piston mounting cavity and a water inlet and a water outlet communicating with the piston mounting cavity.

[0029] The pistons are movably mounted in the piston mounting cavities of both main cylinders, and the two pistons are respectively hinged to the balance bar on both sides of the support structure via connecting rods;

[0030] The first one-way valve is disposed at the water inlet and can be opened in one direction when water is drawn from the water inlet toward the piston mounting cavity; the second one-way valve is disposed at the water outlet and can be opened in one direction when water is discharged from the piston mounting cavity toward the water outlet.

[0031] The fifth guide pipe is connected to the drain outlet;

[0032] The intermittent valve allows the outlets of the two second guide pipes in each group to open alternately, so that the balance bar swings and drives the piston to reciprocate, thereby forcing the water in the lower pool into the fifth guide pipe.

[0033] In an optional embodiment, the first guide pipe is equipped with a valve switch, and when the valve switch is in the open state, water from the energy storage tank can flow into the first guide cavity through the first guide pipe;

[0034] When the valve switch is in the closed state, the valve switch can block the downward flow of water in the first guide pipe.

[0035] In an optional embodiment, the closed-loop power generation system based on the multi-stage conversion of tailwater potential energy further includes an energy storage flow path connected to the energy storage tank and the downstream tank, the energy storage flow path being able to pump water from the downstream tank to the energy storage tank.

[0036] In an optional embodiment, the energy storage flow path includes a pressure pipe, an electric water pump, a second water turbine, a mechanical flow pump, a sixth guide pipe, and a seventh guide pipe;

[0037] The pressure pipe is installed inside the drain tank;

[0038] The water pump is connected to the pressure pipe;

[0039] The second water turbine includes a liquid guide pipe and an axial flow water wheel, the axial flow water wheel being rotatably mounted inside the liquid guide pipe, and the liquid guide pipe being connected to a pressure pipe;

[0040] One end of the sixth guide pipe is connected to the energy storage tank, the outlet of the mechanical flow pump is connected to the other end of the sixth guide pipe, one end of the seventh guide pipe extends into the lower water tank, and the other end is connected to the inlet of the mechanical flow pump.

[0041] The axial flow impeller is connected to the mechanical flow pump via a transmission.

[0042] The operation of the electric water pump causes a pressure change in the pressure pipe, which in turn causes water to flow along the liquid guide pipe, driving the axial flow water wheel to rotate and drive the mechanical flow pump to pump water from the lower pool into the energy storage pool through the seventh guide pipe and the sixth guide pipe.

[0043] In an optional embodiment, one end of the seventh guide pipe extending into the drain tank is connected to the pressure pipe;

[0044] The operation of the electric water pump can pump water from the pressure pipe into the lower water tank to reduce the pressure in the pressure pipe. The negative pressure in the pressure pipe can drive the axial flow water wheel to rotate and drive the mechanical flow pump when water from the lower water tank flows into the pressure pipe through the liquid guide pipe. The operation of the mechanical flow pump can pump water from the pressure pipe into the energy storage tank through the seventh guide pipe and the sixth guide pipe.

[0045] In an optional embodiment, a check valve is provided at the bottom end of the seventh guide pipe, which allows water to flow unidirectionally into the seventh guide pipe.

[0046] A switch valve is provided on the side of the liquid inlet tube used for water intake.

[0047] In an optional embodiment, the high-pressure water storage tank and the water turbine generator set are disposed on top of the energy storage pool, and the outlet of the water turbine generator set is connected to the energy storage pool.

[0048] The beneficial effects of the closed-loop power generation system based on multi-stage conversion of tailwater potential energy provided by this embodiment of the invention include:

[0049] This application utilizes an energy storage pool to store the tailwater from hydropower generation. A lower water tank is installed at the bottom of the energy storage pool, along with a first diversion pipe, a turbine, a second diversion pipe, a third diversion pipe, and a high-pressure water storage tank. The tailwater's gravitational potential energy is used to pressurize it, increasing its kinetic energy and enabling it to drive a turbine generator unit to generate electricity, thus achieving further utilization of the tailwater after power generation at the hydropower station. Attached Figure Description

[0050] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0051] Figure 1 This is a longitudinal sectional view of the closed-loop power generation system for multi-stage conversion of tailwater potential energy provided in this embodiment.

[0052] Figure 2 for Figure 1 A partially enlarged schematic diagram of the pumping mechanism;

[0053] Figure 3 This is another longitudinal cross-sectional schematic diagram of the closed-loop power generation system for multi-stage conversion of tailwater potential energy provided in this embodiment.

[0054] Icons: 100 - Closed-loop power generation system for multi-stage conversion of tailrace potential energy; 101 - Energy storage tank; 102 - Lower tank; 103 - First guide pipe; 104 - Second guide pipe; 105 - Third guide pipe; 106 - Fourth guide pipe; 107 - High-pressure water storage tank; 108 - Hydro-generator unit; 109 - Fifth guide pipe; 130 - Hydro turbine; 131 - Volute casing; 132 - First impeller; 133 - Second impeller; 134 - First guide cavity; 135 - Second guide cavity; 136 - First inlet; 137 - First outlet; 138 - Second inlet; 139 - Second outlet; 150 - Pump Water mechanism; 151-Support structure; 152-Balance bar; 153-Water receiving tank; 154-Main cylinder body; 155-Piston; 156-First check valve; 157-Second check valve; 158-Intermittent valve; 159-Piston mounting cavity; 160-Inlet; 161-Outlet; 170-Valve switch; 180-Energy storage flow path; 181-Pressure pipe; 182-Electric water pump; 183-Second water turbine; 184-Mechanical flow pump; 185-Sixth guide pipe; 186-Seventh guide pipe; 187-Liquid guide pipe; 188-Axial flow turbine; 189-Check valve; 190-Switch valve. Detailed Implementation

[0055] In existing technologies, since the tailwater is insufficient to drive the hydro-turbine generator unit, it is generally discharged directly into the river. The energy in the tailwater can cause scouring and siltation in the downstream river channel, and is also a waste of energy. Therefore, how to achieve stable recovery of tailwater energy has become an urgent technical problem to be solved in this field.

[0056] To address the aforementioned problems, this invention provides a closed-loop power generation system based on multi-stage conversion of tailwater potential energy. This system utilizes the potential energy of the tailwater to pressurize it, increasing its kinetic energy to drive a turbine generator unit for power generation, thereby improving the aforementioned issues.

[0057] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0058] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0059] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0060] In the description of this utility model, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the utility model product is usually placed during use, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0061] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0062] It should be noted that, where there is no conflict, the features in the embodiments of this utility model can be combined with each other.

[0063] The following detailed description of the overall structure, working principle, and technical effects of the closed-loop power generation system based on multi-stage conversion of tailwater potential energy provided by this utility model, through embodiments and in conjunction with the accompanying drawings, is a practical example.

[0064] Please refer to Figure 1 This embodiment provides a closed-loop power generation system 100 based on the multi-stage conversion of tailwater potential energy, which can utilize the potential energy of tailwater to treat tailwater, thereby facilitating the operation of a hydroelectric generator set to generate electricity.

[0065] Please refer to Figure 1In this embodiment, the closed-loop power generation system 100 based on the multi-stage conversion of tailwater potential energy includes an energy storage tank 101, a lower water tank 102, a first guide pipe 103, a turbine 130, a second guide pipe 104, a third guide pipe 105, a fourth guide pipe 106, and a turbine generator set 108. The energy storage tank 101 is used to store the tailwater for hydropower generation. The lower water tank 102 is spaced apart at the bottom of the energy storage tank 101. One end of each of the first guide pipes 103 is connected to the bottom of the energy storage tank 101. The turbine 130 includes a volute 131, a first impeller 132, and a second impeller 133. The volute 131 has a first guide cavity 134 and a second guide cavity 135. The first guide cavity 134 is provided with a first inlet 136 and a first outlet 137. The second guide cavity 135 is provided with a second inlet 138 and a second outlet 139. The first impeller 132 is disposed in the first guide cavity 134, and the second impeller 133 is disposed in the second guide cavity 135, and the first impeller 132 and the second impeller 133 are coaxially connected. The other end of the first guide pipe 103 is connected to the first inlet 136 of the turbine 130, and the first outlet 137 is connected to the second guide pipe 104, which connects to the lower water tank 102. One end of the third guide pipe 105 extends into the lower water tank 102, and the other end is connected to the second inlet 138. One end of the fourth guide pipe 106 is connected to the second outlet 139, and the other end is connected to the inlet of the high-pressure water storage tank 107. The inlet of the water turbine generator set 108 is connected to the outlet of the high-pressure water storage tank 107. The tailwater stored in the lower pool 102 can flow into the first guide cavity 134 through the first guide pipe 103, and then flow back to the lower pool 102 through the second guide pipe 104 to drive the first impeller 132 to rotate and drive the second impeller 133 to rotate. The rotation of the second impeller 133 can pressurize the water in the lower pool 102 and pump it to the high-pressure water storage tank 107, and then flow from the outlet of the high-pressure water storage tank 107 to the water turbine generator set 108 to drive the water turbine generator set 108 to generate electricity.

[0066] In this embodiment, a water storage tank 101 is set up to store the tailwater of hydropower generation. A lower water tank 102 is set up at the bottom of the water storage tank 101. A first guide pipe 103, a water turbine 130, a second guide pipe 104, a third guide pipe 105 and a high-pressure water storage tank 107 are set up to pressurize the tailwater by utilizing the gravitational potential energy of the tailwater, thereby increasing the kinetic energy of the tailwater and driving the hydro-generator unit 108 to generate electricity, so as to realize the further utilization of the tailwater after the hydropower station generates electricity.

[0067] Please refer to Figure 1 In this embodiment, the energy storage tank 101 and the lower water tank 102 are generally formed by reinforced concrete casting. A certain height difference is formed between the two, which is within 22 meters. The tailwater after the hydroelectric power station generates electricity can be diverted to the energy storage tank 101 through pipelines, diversion channels, etc.

[0068] Generally, multiple flow paths are arranged between the energy storage tank 101 and the lower water tank 102, forming a flow path through the first guide pipe 103, the second guide pipe 104, the third guide pipe 105, the fourth guide pipe 106, and the turbine 130. These flow paths can utilize the potential energy of the water to increase the water pressure, thereby converting potential energy into kinetic energy and improving power generation efficiency. Typically, the first guide pipe 103 and the second guide pipe 104 have larger diameters, while the third guide pipe 105 and the fourth guide pipe 106 have relatively smaller diameters, thus facilitating better water pressurization.

[0069] The high-pressure water storage tank 107 mainly collects water that has been pressurized by multiple sets of pipes, including the first guide pipe 103, the second guide pipe 104, the third guide pipe 105, the fourth guide pipe 106, and the turbine 130, to facilitate the supply of high-pressure water to a turbine generator set 108. The high-pressure water storage tank 107 also serves as a buffer and regulator.

[0070] For example, the first guide pipe 103 and the second guide pipe 104 inject water from the top energy storage tank 101 into the lower water tank 102 at a rate of 1000 cubic meters per minute to drive the first impeller 132 of the turbine 130 to rotate. The potential energy of the water flowing downwards from the top energy storage tank 101 drives the first impeller 132 of the turbine 130 to rotate, converting the potential energy of the water into mechanical energy. At the same time, the second impeller 133 of the turbine 130, which is coaxially connected to the first impeller 132, can pressurize the water in the lower water tank 102 through the third guide pipe 105 and the fourth guide pipe 106 and pump it to the high-pressure water storage tank 107 at a rate of 300 cubic meters per minute to increase the kinetic energy of the water, so as to ensure that the turbine generator connected to the high-pressure water tank can generate electricity stably.

[0071] Please refer to Figure 1 In this embodiment, the high-pressure water storage tank 107 and the water turbine generator set 108 are located on the top of the energy storage pool 101, and the outlet of the water turbine generator set 108 is connected to the energy storage pool 101.

[0072] The high-pressure water storage tank 107 and the water turbine generator set 108 are set on the top of the energy storage pool 101, and the outlet of the water turbine generator set 108 is connected to the energy storage pool 101. The water after power generation flows back to the energy storage pool 101 to form a cycle. The gravitational potential energy of water can be used to generate electricity continuously, and it saves space. It forms a three-layer cycle in space.

[0073] Of course, in other embodiments of this application, the high-pressure water storage tank 107 and the water turbine generator set 108 may be located at the same height as the lower water tank 102 or at a lower height relative to the lower water tank 102. The specific arrangement can be determined according to the terrain.

[0074] Please refer to Figure 1In this embodiment, the first inlet 136 and the first outlet 137 are arranged radially opposite each other along the first impeller 132. The second inlet 138 is located axially on the second impeller 133, and the second outlet 139 is located radially on the second impeller 133. The end of the third guide pipe 105 away from the second inlet 138 extends to a position near the bottom of the lower water tank 102, which facilitates energy conversion by the turbine 130.

[0075] Please refer to Figure 1 and Figure 2 In this embodiment, a pumping mechanism 150 is provided inside the sink 102, and the pumping mechanism 150 corresponds to the outlet of the second guide pipe 104. The pumping mechanism 150 is also provided with a fifth guide pipe 109 that communicates with the high-pressure water storage tank 107. The water flowing down the second guide pipe 104 can drive the pumping mechanism 150 to operate, so that the water in the sink 102 is pressurized through the fifth guide pipe 109 and pumped to the high-pressure water storage tank 107.

[0076] This embodiment is equipped with a pumping mechanism 150, which can further utilize the energy of the water flowing down the second guide pipe 104 to pressurize the water and pump it to the high-pressure water storage tank 107.

[0077] Specifically, the pumping mechanism 150 includes a support structure 151, a balance bar 152, a water receiving trough 153, a main cylinder 154, a piston 155, a first one-way valve 156, and a second one-way valve 157. Multiple pairs of second guide pipes 104 are arranged, and an intermittent valve 158 is provided at the outlet end of each second guide pipe 104. The support structure 151 is located in the lower water tank 102 and is positioned at the center of the distance between the two second guide pipes 104 in each group. The middle part of the balance bar 152 is rotatably connected to the support structure 151. A water receiving trough 153 is provided at the outlet position of each pair of second guide pipes 104 in each group on the balance bar 152. Main cylinders 154 are spaced apart on both sides of the support structure 151. Each main cylinder 154 has a piston mounting cavity 159 and a suction port 160 and a discharge port 161 communicating with the piston mounting cavity 159. Pistons 155 are movably mounted in the piston mounting chambers 159 of both main cylinders 154. The two pistons 155 are hinged to the balance bar 152 on both sides of the support structure 151 via connecting rods. A first one-way valve 156 is located at the suction port 160 and opens unilaterally when water is drawn from the suction port 160 into the piston mounting chamber 159. A second one-way valve 157 is located at the discharge port 161 and opens unilaterally when water is discharged from the piston mounting chamber 159 into the discharge port 161. A fifth guide pipe 109 is connected to the discharge port 161. An intermittent valve 158 allows the outlets of the two second guide pipes 104 in each group to open alternately, causing the balance bar 152 to swing and drive the pistons 155 to reciprocate, thus forcing water from the lower pool 102 into the fifth guide pipe 109.

[0078] The outlet of the second guide pipe 104 is alternately opened by the intermittent valve 158, using the intermittent impact force of the water flow to drive the balance rod 152 to swing. This method can effectively utilize the energy of the water flow, transforming what might have been a continuous but energy-dispersed water flow into an intermittent flow with greater impact force, thereby better driving the balance rod 152 and the subsequent piston 155. The balance rod 152 is rotatably connected to the support structure 151, and its two ends are hinged to the piston 155 via connecting rods, forming a lever-like structure. Utilizing the lever principle, the torque generated at one end of the balance rod 152 by a smaller water flow impact force can be converted into a larger force acting on the piston 155, achieving force amplification and improving energy conversion efficiency. This allows the piston 155 to move with a smaller water flow energy, forcing water from the lower pool 102 into the fifth guide pipe 109. The first one-way valve 156 and the second one-way valve 157 ensure unidirectional water flow. The first one-way valve 156 allows water to flow only from the lower water tank 102 into the piston mounting chamber 159, and the second one-way valve 157 allows water to flow only from the piston mounting chamber 159 to the fifth guide pipe 109, thus avoiding backflow of water, ensuring the normal operation of the pumping mechanism 150, improving the stability and reliability of the system, and further recovering the potential energy of the water flowing downward through the second guide pipe 104.

[0079] It should be noted that the intermittent valve 158 can be an electric valve, a gravity valve, or even be linked to the balance bar 152 via a linkage mechanism. When one end of the balance bar 152 is raised, the linkage mechanism gradually opens the gap valve on that side. At the same time, the other end of the balance bar 152 gradually descends, causing the linkage mechanism to gradually close the gap valve on that side, thereby realizing the intermittent opening and closing of the intermittent valve 158, and achieving one side open and the other side closed.

[0080] Please refer to Figure 1 and Figure 2 In this embodiment, the first guide pipe 103 is equipped with a valve switch 170. When the valve switch 170 is in the open state, water from the energy storage tank 101 can flow into the first guide cavity 134 through the first guide pipe 103. When the valve switch 170 is in the closed state, the valve switch 170 can block the downward flow of water from the first guide pipe 103.

[0081] This implementation includes a valve switch 170, which can be used for equipment maintenance, facilitating maintenance.

[0082] Please refer to Figure 3 In this embodiment, the closed-loop power generation system 100 based on the multi-stage conversion of tailwater potential energy also includes an energy storage flow path 180 connected to the energy storage pool 101 and the downstream pool 102. The energy storage flow path 180 can pump water from the downstream pool 102 to the energy storage pool 101.

[0083] In this embodiment, an energy storage flow path 180 is set up. During the off-peak period of electricity consumption, water can be pumped from the lower water tank 102 to the energy storage tank 101 through the energy storage flow path 180 to replenish the energy storage tank 101, so that more water can be used to generate electricity during the peak period of electricity consumption.

[0084] In this embodiment, the energy storage flow path 180 includes a pressure pipe 181, an electric water pump 182, a second water turbine 183, a mechanical flow pump 184, a sixth guide pipe 185, and a seventh guide pipe 186. The pressure pipe 181 is located within the lower water tank 102. The water pump is connected to the pressure pipe 181. The second water turbine 183 includes a liquid guide pipe 187 and an axial flow water wheel 188. The axial flow water wheel 188 is rotatably mounted within the liquid guide pipe 187, which is connected to the pressure pipe 181. One end of the sixth guide pipe 185 is connected to the energy storage tank 101, and the outlet of the mechanical flow pump 184 is connected to the other end of the sixth guide pipe 185. One end of the seventh guide pipe 186 extends into the lower water tank 102, and the other end is connected to the inlet of the mechanical flow pump 184. The axial flow water wheel 188 is drive-connected to the mechanical flow pump 184. The operation of the electric water pump 182 can change the pressure of the pressure pipe 181, so that water flows along the liquid guide pipe 187 and drives the axial flow water wheel 188 to rotate, thereby driving the mechanical flow pump 184 to pump water in the lower water tank 102 into the energy storage water tank 101 through the seventh guide pipe 186 and the sixth guide pipe 185.

[0085] In this embodiment, an electric water pump 182 changes the pressure within the pressure pipe 181, driving water flow through the guide pipe 187 to rotate the axial flow turbine 188, which in turn drives the mechanical flow pump 184 via mechanical transmission. This process converts electrical energy into the mechanical energy of the turbine 130, and then the mechanical flow pump 184 pumps the water from the lower water tank 102 to the energy storage tank 101, forming a conversion chain of "electrical energy → mechanical energy → potential energy". Simultaneously, it allows for micro-circulation of the residual water in the pressure pipe 181 and the water in the lower water tank 102. Compared to directly using a water pump to pump water from the lower water tank 102 to the energy storage tank 101, this reduces the load requirement of the electric water pump 182, extending its service life. Furthermore, one electric water pump 182 can be used to drive more sets of seventh guide pipes 186 and sixth guide pipes 185 to pump water upwards.

[0086] Please refer to Figure 3In this embodiment, one end of the seventh guide pipe 186 extending into the lower water tank 102 is connected to the pressure pipe 181. The operation of the electric water pump 182 can pump water from the pressure pipe 181 into the lower water tank 102 to reduce the pressure in the pressure pipe 181. The negative pressure in the pressure pipe 181 can drive the axial flow water wheel 188 to rotate when water from the lower water tank 102 flows into the pressure pipe 181 through the liquid guide pipe 187, thereby driving the mechanical flow pump 184 to operate. The operation of the mechanical flow pump 184 can pump water from the pressure pipe 181 into the energy storage tank 101 through the seventh guide pipe 186 and the sixth guide pipe 185.

[0087] The electric water pump 182 creates negative pressure, using atmospheric pressure and water flow potential energy to drive the turbine 130, which in turn uses a mechanical pump to complete the pumping, forming a cycle of "negative pressure diversion → mechanical energy conversion → pumping and energy storage". Compared to traditional water pumps that need to overcome the "static head" of water level difference and pipeline resistance when directly pumping water, this design uses negative pressure diversion to allow water in the sink 102 to "passively flow" into the pressure pipe 181 under atmospheric pressure, which can partially offset the energy consumption of static head. Secondly, both the electric water pump 182 pumping water into the sink 102 and the sink 102 discharging water outwards will give the water in the sink 102 a certain flow velocity, which can directly capture kinetic energy through the liquid guide pipe 187, reducing the energy consumption of the electric water pump 182.

[0088] Please refer to Figure 3 In this embodiment, a check valve 189 is provided at the bottom end of the seventh guide pipe 186, which allows water to flow unidirectionally into the seventh guide pipe 186.

[0089] In this embodiment, a check valve 189 is provided at the bottom of the fifth guide pipe 109 to prevent water from flowing back under the action of gravity, thereby improving the efficiency of upward water pumping.

[0090] In this embodiment, a switch valve 190 is provided on the side of the liquid inlet pipe 187. The switch valve 190 is normally open during normal use, but can be closed during maintenance for ease of maintenance.

[0091] In this embodiment, the pressure pipe 181 is a pre-formed pressure pipe 181 corridor integrally cast with the drain tank 102 through concrete pouring, and its two ends are closed.

[0092] Furthermore, another check valve 189 is also installed at the top of the seventh guide pipe 186 to prevent backflow.

[0093] In summary, this embodiment uses an energy storage tank 101 to store the tailwater of hydropower generation, and a lower water tank 102 is set at the bottom of the energy storage tank 101. A first guide pipe 103, a water turbine 130, a second guide pipe 104, a third guide pipe 105, and a high-pressure water storage tank 107 are set up to pressurize the tailwater using the gravitational potential energy, thereby increasing the kinetic energy of the tailwater and driving the hydro-generator unit 108 to generate electricity, so as to realize the further utilization of the tailwater after the hydropower station generates electricity.

[0094] The above description is only a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model.

Claims

1. A closed cycle power generation system based on multi-stage conversion of tailwater potential energy, characterized by, include: Energy storage tank (101) is used to store tailwater from hydroelectric power generation; The lower water tank (102) is spaced apart at the bottom of the energy storage tank (101); The first guide pipe (103) has one end connected to the bottom of the energy storage tank (101); A water turbine (130) includes a volute (131), a first impeller (132), and a second impeller (133). The volute (131) has a first guide cavity (134) and a second guide cavity (135). The first guide cavity (134) is provided with a first inlet (136) and a first outlet (137). The second guide cavity (135) is provided with a second inlet (138) and a second outlet (139). The first impeller (132) is disposed in the first guide cavity (134), and the second impeller (133) is disposed in the second guide cavity (135). The first impeller (132) and the second impeller (133) are coaxially connected. The other end of the first guide pipe (103) is connected to the first inlet (136) of the water turbine (130), and the first outlet (137) is connected to the second guide pipe (104), which is connected to the lower water tank (102). The third guide pipe (105) extends one end into the drain pool (102) and the other end is connected to the second inlet (138); The fourth guide pipe (106) is connected at one end to the second outlet (139) and at the other end to the inlet of the high-pressure water storage tank (107); A water turbine generator set (108) is provided, wherein the inlet of the water turbine generator set (108) is connected to the outlet of the high-pressure water storage tank (107); The tailwater stored in the sink (102) can flow into the first guide cavity (134) through the first guide pipe (103), and then flow back to the sink (102) through the second guide pipe (104) to drive the first impeller (132) to rotate and drive the second impeller (133) to rotate. The rotation of the second impeller (133) can pressurize the water in the sink (102) and pump it to the high-pressure water storage tank (107), and then flow from the outlet of the high-pressure water storage tank (107) to the water turbine generator set (108) to drive the water turbine generator set (108) to move and generate electricity.

2. The closed-loop power generation system based on multi-stage conversion of tailwater potential energy according to claim 1, characterized in that, The first inlet (136) and the first outlet (137) are arranged radially opposite each other along the first impeller (132); The second inlet (138) is located axially on the second impeller (133), and the second outlet (139) is located radially on the second impeller (133); The third guide pipe (105) extends from the end away from the second inlet (138) to the bottom of the drain pool (102).

3. The closed-loop power generation system based on multi-stage conversion of tailwater potential energy according to claim 1, characterized in that, The lower water tank (102) is equipped with a water pumping mechanism (150), which corresponds to the outlet of the second guide pipe (104); The pumping mechanism (150) is also provided with a fifth guide pipe (109) that is connected to the high-pressure water storage tank (107); The water flowing down the second guide pipe (104) can drive the pumping mechanism (150) to operate, so as to pump the water in the lower pool (102) to the high-pressure water storage tank (107) after being pressurized by the fifth guide pipe (109).

4. The closed-loop power generation system based on multi-stage conversion of tailwater potential energy according to claim 3, characterized in that, The pumping mechanism (150) includes a support structure (151), a balance bar (152), a water receiving tank (153), a main cylinder (154), a piston (155), a first check valve (156), and a second check valve (157). The second guide pipe (104) has multiple sets arranged in pairs, and the outlet end of the second guide pipe (104) is provided with an intermittent valve (158); The support structure (151) is disposed in the sink (102) and is disposed at the center of the distance between the two second guide pipes (104) in each group; The middle part of the balance bar (152) is rotatably connected to the support structure (151); The balance bar (152) is provided with a water receiving trough (153) at the outlet position of each of the two second guide pipes (104) in each group; The main cylinder (154) is provided on both sides of the support structure (151) at intervals. The main cylinder (154) has a piston mounting cavity (159) and a water inlet (160) and a water outlet (161) communicating with the piston mounting cavity (159). The pistons (155) are movably installed in the piston mounting cavities (159) of the two main cylinder bodies (154), and the two pistons (155) are respectively hinged to the balance bar (152) on both sides of the support structure (151) via connecting rods; The first one-way valve (156) is disposed at the water inlet (160) and can be opened in one direction when the water inlet (160) draws water into the piston mounting cavity (159); the second one-way valve (157) is disposed at the drain outlet (161) and can be opened in one direction when the piston mounting cavity (159) drains water into the drain outlet (161). The fifth guide pipe (109) is connected to the drain outlet (161); The intermittent valve (158) allows the outlets of the two second guide pipes (104) in each group to open alternately, so that the balance bar (152) swings and drives the piston (155) to reciprocate, thereby forcing the water in the lower pool (102) into the fifth guide pipe (109).

5. The closed-loop power generation system based on multi-stage conversion of tailwater potential energy according to claim 1, characterized in that, The first guide pipe (103) is equipped with a valve switch (170). When the valve switch (170) is in the open state, the water in the energy storage tank (101) can flow into the first guide cavity (134) through the first guide pipe (103). When the valve switch (170) is in the closed state, the valve switch (170) can block the downward flow of water in the first guide pipe (103).

6. The closed-loop power generation system based on multi-stage conversion of tailwater potential energy according to claim 1, characterized in that, The closed-loop power generation system based on the multi-stage conversion of tailwater potential energy also includes an energy storage flow path (180) connected to the energy storage tank (101) and the lower water tank (102), which can pump water from the lower water tank (102) to the energy storage tank (101).

7. The closed-loop power generation system based on multi-stage conversion of tailwater potential energy according to claim 6, characterized in that, The energy storage flow path (180) includes a pressure pipe (181), an electric water pump (182), a second water turbine (183), a mechanical flow pump (184), a sixth guide pipe (185), and a seventh guide pipe (186); The pressure pipe (181) is installed inside the drain tank (102); The water pump is connected to the pressure pipe (181); The second water turbine (183) includes a liquid guide pipe (187) and an axial flow water wheel (188), the axial flow water wheel (188) being rotatably installed inside the liquid guide pipe (187), the liquid guide pipe (187) being connected to a pressure pipe (181); One end of the sixth guide pipe (185) is connected to the energy storage tank (101), the outlet of the mechanical flow pump (184) is connected to the other end of the sixth guide pipe (185), one end of the seventh guide pipe (186) extends into the lower water tank (102), and the other end is connected to the inlet of the mechanical flow pump (184). The axial flow water impeller (188) is connected to the mechanical flow pump (184) in a transmission connection; The operation of the electric water pump (182) can change the pressure of the pressure pipe (181), so that water flows along the liquid guide pipe (187) and drives the axial flow water wheel (188) to rotate, thereby driving the mechanical flow pump (184) to pump water in the lower water tank (102) into the energy storage tank (101) through the seventh guide pipe (186) and the sixth guide pipe (185).

8. The closed-loop power generation system based on multi-stage conversion of tailwater potential energy according to claim 7, characterized in that, The seventh guide pipe (186) extends into the sink (102) and is connected to the pressure pipe (181) at one end; The operation of the electric water pump (182) can pump water in the pressure pipe (181) into the lower water tank (102) to reduce the pressure in the pressure pipe (181). The negative pressure in the pressure pipe (181) can drive the axial flow water wheel (188) to rotate and drive the mechanical flow pump (184) to operate. The operation of the mechanical flow pump (184) can pump water in the pressure pipe (181) into the energy storage tank (101) through the seventh guide pipe (186) and the sixth guide pipe (185).

9. The closed-loop power generation system based on multi-stage conversion of tailwater potential energy according to claim 7 or 8, characterized in that, A check valve (189) is provided at the bottom end of the seventh guide pipe (186), and the check valve (189) allows water to flow unidirectionally into the seventh guide pipe (186). The liquid guide tube (187) is equipped with a switch valve (190) on the side for water inlet.

10. The closed-loop power generation system based on multi-stage conversion of tailwater potential energy according to any one of claims 1-8, characterized in that, The high-pressure water storage tank (107) and the water turbine generator set (108) are located on the top of the energy storage pool (101), and the outlet of the water turbine generator set (108) is connected to the energy storage pool (101).

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