CN114688016B

CN114688016B - Bidirectional sealing piston and hydraulic energy storage system with same

Info

Publication number: CN114688016B
Application number: CN202210374894.5A
Authority: CN
Inventors: 马哲; 李鹏; 杨静
Original assignee: China Three Gorges Corp
Current assignee: China Three Gorges Corp
Priority date: 2022-04-11
Filing date: 2022-04-11
Publication date: 2023-06-09
Anticipated expiration: 2042-04-11
Also published as: CN114688016A

Abstract

The invention relates to the technical field of energy storage equipment, in particular to a bidirectional sealing piston and a hydraulic energy storage system with the bidirectional sealing piston. The piston includes: the piston body is of a columnar structure, the side wall of the piston body is provided with at least one annular groove, and the annular groove is coaxial with the piston body; the main sealing ring is sleeved in the annular groove, and the outer side wall of the main sealing ring protrudes outwards from the piston body; the two auxiliary sealing rings are sleeved in the annular groove and symmetrically distributed on two axial sides of the main sealing ring, the auxiliary sealing rings are in contact with the main sealing ring, an annular gap is formed in the surface of the auxiliary sealing ring, which is far away from the main sealing ring in the axial direction, and the auxiliary sealing ring has a natural state when the piston stops moving and a pressed state when the piston moves and is radially deformed under pressure; the two gland rings are symmetrically distributed on two axial sides of the main sealing ring and are in contact with the auxiliary sealing ring. This structure can play dual seal, also makes sealing pressure dispersion on main sealing ring and vice sealing ring when improving sealed effect, has reduced the loss of main sealing ring.

Description

Bidirectional sealing piston and hydraulic energy storage system with same

Technical Field

The invention relates to the technical field of energy storage equipment, in particular to a bidirectional sealing piston and a hydraulic energy storage system with the bidirectional sealing piston.

Background

The piston is a part which slides reciprocally in the cylinder, and is generally provided with a sealing assembly on its outer side wall, through which the piston is kept sealed from the inner wall of the cylinder to isolate the two sides of the piston and thereby form a driving force.

The existing sealing assembly generally adopts simple structures such as a sealing ring and the like, and sealing is realized only by virtue of the preset interference pressing force between the sealing ring and the inner wall of the cylinder body, so that the stress of the sealing structure is concentrated, and along with the reciprocating motion of a piston, structural fatigue is easy to occur, and the tightness is influenced. In particular, in the fields of hydraulic energy storage and the like, when the piston volume is large, the defect is more obvious.

Disclosure of Invention

Therefore, the technical problem to be solved by the invention is to overcome the defects that the piston sealing assembly is easy to generate structural fatigue and influence the tightness in the prior art, thereby providing a bidirectional sealing piston and a hydraulic energy storage system with the bidirectional sealing piston.

The invention provides a bidirectional sealing piston, comprising:

the piston body is of a columnar structure, the side wall of the piston body is provided with at least one annular groove, and the annular groove is coaxial with the piston body;

the main sealing ring is sleeved in the annular groove, and the outer side wall of the main sealing ring protrudes outwards from the piston body;

the two auxiliary sealing rings are sleeved in the annular groove and symmetrically distributed on two axial sides of the main sealing ring, the auxiliary sealing rings are in contact with the main sealing ring, annular gaps are formed in the surfaces, far away from the main sealing ring, of the auxiliary sealing rings in the axial direction, and the auxiliary sealing rings are in a natural state when the piston stops moving and in a pressed state when the piston moves and is radially deformed under pressure;

the two gland rings are symmetrically distributed on two axial sides of the main sealing ring and are in contact with the auxiliary sealing ring;

the inner side wall of the main sealing ring is provided with a groove, a supporting body is accommodated in the groove, and the supporting body has a natural state when the piston stops moving and a pressed state when the piston moves and is radially deformed under pressure;

the outer side wall of the gland ring protrudes outwards from the piston body and is provided with a plurality of layers of bulges, and the gland ring is in a natural state when the piston stops moving and in a pressed state when the piston moves and is radially deformed under pressure.

Optionally, two ring grooves are set up on the side wall of the piston body, the two ring grooves are located on the end of the piston body respectively, and a main sealing ring, two auxiliary sealing rings and two gland rings are sleeved in each ring groove.

Optionally, the piston body includes:

a piston body;

the piston top is fixed at the first end of the piston main body through a first countersunk head screw, and a first buffer sheet is arranged between the piston top and the piston main body in a cushioning mode;

the piston bottom is fixed at the second end of the piston main body through a second countersunk head screw, and a second buffer sheet is arranged between the piston bottom and the piston main body in a cushioning mode.

Optionally, the end face of the piston top far away from the piston main body and the end face of the piston bottom far away from the piston main body are both fixed with protection pads.

Optionally, counter bores are formed in the top and the bottom of the piston, the head of the first countersunk head screw and the head of the second countersunk head screw are placed in the corresponding counter bores, sealing parts extending into the counter bores are protruded outwards from the positions of the protection pad corresponding to the first countersunk head screw or the second countersunk head screw, and the sealing parts are sleeved in the counter bores in an interference mode to seal the countersunk head screws.

Optionally, the piston bottom is heavier than the piston top.

The invention provides a hydraulic energy storage system, comprising:

an upstream water source;

the vertical shaft is internally provided with the bidirectional sealing piston, the piston body is coaxial with the vertical shaft, and the outer side wall of the main sealing ring is attached to the inner wall of the vertical shaft;

one end of the reversible water pump turbine is communicated with the upstream water source, and the other end of the reversible water pump turbine is communicated with the bottom of the vertical shaft;

the generator set is connected with the reversible water pump turbine and is suitable for being combined with the reversible water pump turbine to generate power in the energy release process;

the upstream water source is an external reservoir or a vertical shaft part positioned on the upper side of the piston.

Optionally, the shaft is equipped with a plurality of, and the bottom of every shaft all is connected with reversible pump hydraulic turbine through the valve.

The technical scheme of the invention has the following advantages:

1. the bidirectional sealing piston provided by the invention is provided with the main sealing ring, the auxiliary sealing ring and the gland ring, when the piston moves, the gland ring at the rear of the piston movement direction can squeeze the auxiliary sealing ring due to friction force between the main sealing ring and the cylinder body, and the auxiliary sealing ring is provided with the annular notch, so that the annular notch can expand and outwards extend to deform at two sides under the squeezing action of the gland ring until the auxiliary sealing ring is abutted on the inner wall of the cylinder body, thereby playing a sealing role. Therefore, the auxiliary sealing ring and the main sealing ring can perform double sealing, sealing pressure is dispersed on the main sealing ring and the auxiliary sealing ring while sealing effect is improved, and loss of the main sealing ring is reduced. In addition, the piston of this application is equipped with two sets of vice sealing rings and gland ring in the both sides of main sealing ring, and when the piston direction of motion was different, only the gland ring extrusion pair sealing ring that is in piston direction of motion rear can extrude vice sealing ring to play sealed effect, so can realize two-way seal, and shared the wearing and tearing that the piston reciprocating motion caused for two sets of seal structure, further reduced wearing and tearing, reduced the probability that structural fatigue took place, guaranteed sealing performance.

2. According to the bidirectional sealing piston provided by the invention, the inner side wall of the main sealing ring is provided with the groove, the supporting body is arranged in the groove, and when the piston moves, the supporting body is pressed and radially deformed, so that the main sealing ring is extruded towards the direction of the inner wall of the cylinder body, the pressure between the main sealing ring and the cylinder body is improved, and the sealing effect is improved.

3. According to the bidirectional sealing piston provided by the invention, the multilayer protrusions are arranged on the outer side wall of the gland ring, so that certain sealing performance can be provided by compression deformation, and when the piston is rocked to incline, the piston can firstly contact the inner wall of the cylinder body, so that the piston body is prevented from touching the cylinder body, and the piston body is protected.

4. According to the bidirectional sealing piston provided by the invention, the two annular grooves are formed in the side wall of the piston body, the main sealing ring, the two auxiliary sealing rings and the two gland rings are sleeved in each annular groove, double-layer sealing can be provided, and each group of sealing structures can realize bidirectional sealing, so that even if one group fails, the other group can realize sealing independently, and the reliability of the piston is improved.

5. The bidirectional sealing piston provided by the invention comprises a piston main body, a piston top and a piston bottom, and is more convenient to mount and dismount and low in operation and maintenance difficulty; and buffer sheets are respectively arranged between the top and bottom of the piston and the piston main body, so that the piston can play a role in axial buffer when being abutted to the top or bottom of the cylinder body, and the piston main body is prevented from being damaged.

6. According to the bidirectional sealing piston provided by the invention, the protection pads are arranged on the end surfaces of the top and the bottom of the piston, which are far away from the piston main body, so that further buffering can be provided, and the piston body is protected.

7. According to the bidirectional sealing piston provided by the invention, the counter bores are formed in the top and the bottom of the piston, the sealing gasket is provided with the sealing part corresponding to the counter bores, and the sealing part is in interference fit with the counter bores, so that the countersunk head screw can be sealed, water outside the piston is prevented from entering the counter bores, the countersunk head screw is prevented from rusting, and the service life of the countersunk head screw is ensured.

8. The weight of the bottom of the piston is larger than that of the top of the piston, so that the gravity center of the whole piston is lowered, and the piston is stable in movement.

9. The hydraulic energy storage system provided by the invention has any one of the advantages due to the bidirectional sealing piston. In addition, the hydraulic energy storage system adopts the vertical shaft as the cylinder body, and the system can be totally built underground except an upstream water source adopts a reservoir, so that the system can be planned and built under various terrain conditions including platform terrain, and has low influence on surrounding environment; the high density piston replaces the body of water to store gravitational potential energy that is much greater than the same volume of water, thus reducing the space required to construct the system.

10. The hydraulic energy storage system provided by the invention can flexibly select the number of the vertical shafts with different numbers according to the requirement of energy storage capacity, and the vertical shafts are mutually independent, so that the system is convenient to install and disassemble and easy to deploy.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments or the prior art will be briefly described, and it is obvious that the drawings in the description below are some embodiments of the present invention, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic view showing a partial structure of a piston in embodiment 1 of the present invention;

FIG. 2 is a schematic view showing the overall structure of a piston (excluding the structure in the annular groove) in embodiment 1 of the present invention;

FIG. 3 is a schematic diagram of a front view of a hydraulic energy storage system according to embodiment 2 of the present invention;

FIG. 4 is a schematic top view of a hydraulic energy storage system according to embodiment 2 of the present invention;

fig. 5 is a schematic diagram of a front view of a hydraulic energy storage system according to embodiment 3 of the present invention.

Reference numerals illustrate:

1. a piston body; 11. an annular groove; 12. a piston body; 13. a piston top; 14. the bottom of the piston; 15. a first countersunk head screw; 16. a second countersunk head screw; 17. a first buffer sheet; 18. a second buffer sheet; 19. a protective pad; 191. a sealing part; 2. a primary seal ring; 21. a groove; 22. a support body; 3. a secondary seal ring; 31. an annular gap; 4. a gland ring; 41. a protrusion; 5. a reservoir; 6. a shaft; 7. reversible pump turbine; 8. a generator set; 9. and (3) a valve.

Detailed Description

The following description of the embodiments of the present invention will be made apparent and fully in view of the accompanying drawings, in which some, but not all embodiments of the invention are shown. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present invention and simplifying the description, and do not indicate or imply that the apparatus or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

In addition, the technical features of the different embodiments of the present invention described below may be combined with each other as long as they do not collide with each other.

Example 1

The specific embodiment of the bi-directional sealed piston shown in fig. 1-2 includes:

the piston body 1 is of a columnar structure, the side wall of the piston body is provided with at least one annular groove 11, and the annular groove 11 is coaxial with the piston body 1;

the main sealing ring 2 is sleeved in the annular groove 11, and the outer side wall of the main sealing ring 2 protrudes outwards from the piston body 1;

the two auxiliary sealing rings 3 are sleeved in the annular groove 11 and symmetrically distributed on two axial sides of the main sealing ring 2, the auxiliary sealing rings 3 are in contact with the main sealing ring 2, annular gaps 31 are formed in the surfaces, far away from the main sealing ring 2, of the auxiliary sealing rings 3 in the axial direction, and the auxiliary sealing rings 3 are in a natural state when the piston stops moving and in a pressed state when the piston is pressed and radially deformed;

the two gland rings 4 are symmetrically distributed on two sides of the axial direction of the main seal ring 2 and are in contact with the auxiliary seal ring 3.

When the piston moves, the gland ring 4 positioned at the rear of the movement direction of the piston can squeeze the auxiliary sealing ring 3 due to the friction force between the main sealing ring 2 and the cylinder body, and the auxiliary sealing ring 3 is provided with the annular gap 31, so that the annular gap 31 swells and extends outwards and deforms at two sides until abutting against the inner wall of the cylinder body under the squeezing action of the gland ring 4, thereby playing a role in sealing. So, vice sealing ring 3 and main sealing ring 2 can play double seal, also make sealing pressure disperse on main sealing ring 2 and vice sealing ring 3 when improving sealed effect, have reduced the loss of main sealing ring 2. In addition, the piston of this application is equipped with two sets of vice sealing rings 3 and gland ring 4 in the both sides of main sealing ring 2, and when the piston direction of motion was different, only the gland ring 4 extrusion pair sealing ring 3 that is in piston direction of motion rear can extrude vice sealing ring 3 to play sealed effect, so can realize two-way seal, and shared the wearing and tearing that the piston reciprocating motion caused and given two sets of seal structure, further reduced wearing and tearing, reduce the probability that structural fatigue takes place, guarantee sealing performance.

In the above embodiment, the shape of the piston body 1 is not limited, and may be cylindrical or prismatic, and preferably cylindrical in the drawing is adopted, so that the abrasion of the piston due to the structural edges and corners is prevented from being increased and the sealing performance is poor.

In particular, the shape of the annular groove 11 is dependent on the shape of the piston body 1. If the piston body 1 adopts a cylindrical shape, the annular groove 11 is annular; if the piston body 1 adopts a prismatic shape, the annular groove 11 is rectangular annular.

In the above embodiment, the material of the piston body 1 is not limited, and is preferably made of high-density and low-cost materials such as rock or industrial waste, so that the potential energy storage capacity of the piston in unit volume can be improved, and the piston is more beneficial to be applied to the hydraulic energy storage system.

It should be understood that the main seal ring 2 mainly performs a sealing function, so that a sealing material having deformability, such as rubber, silicone, etc., which is commonly used in the art, may be used.

It is easy to understand that the amount of the outer side wall of the main sealing ring 2 protruding out of the piston body 1 should be moderate, and too large would easily cause the main sealing ring 2 to deform due to the gravity of the piston body 1, and too small would easily cause the outer side wall of the piston body 1 to rub against the outer side wall of the cylinder body, increasing the resistance, and causing the abrasion of the piston body 1.

It will be readily appreciated that the secondary seal ring 3 has a natural state and a compressed state and is desirably made of a deformable material such as rubber.

In the above embodiment, the shape of the annular gap 31 is not limited, and may be a semi-elliptical groove in fig. 1, so as to avoid the fracture caused by stress concentration, or may be a V-shape or other common shape.

Specifically, the part of the gland ring 4 facing the annular gap 31 may be provided with a smooth tip structure, and when the gland ring 4 presses the auxiliary sealing ring 3, the smooth tip structure can directly extend into the annular gap 31, so as to guide the annular gap 31 to expand outwards towards two sides, and reduce unnecessary deformation in other directions.

In the above embodiment, the gland ring 4 may be a rigid structure which is not easily deformed, or may be a deformable structure such as rubber or silicone. The main function is to transmit pressure to the secondary seal ring 3 to deform it, thereby achieving sealing.

It will be readily appreciated that the overall length of the primary seal ring 2, the secondary seal ring 3 and the gland ring 4 in the axial direction should be substantially the same as the axial length of the annular groove 11 so that the secondary seal ring 3 is more likely to deform when compression occurs. Of course, substantially uniform, i.e. equal to or slightly less than the axial length of the annular groove 11.

As an improved embodiment of the main seal ring 2, a groove 21 is formed in the inner side wall of the main seal ring 2, a support body 22 is accommodated in the groove 21, and the support body 22 has a natural state when the piston stops moving and a pressed state when the piston is pressed and radially deformed. When the piston moves, the support body 22 is radially deformed under pressure, so that the main sealing ring 2 is extruded towards the inner wall of the cylinder, the pressure between the main sealing ring 2 and the cylinder is increased, and the sealing effect is improved.

The number and cross-sectional shape of the supporting bodies 22 are not limited, and may be one or two or even more, and the cross-sectional shape may be rectangular or circular, preferably circular in fig. 1, and the number is set to 2, so that bidirectional sealing of the piston is facilitated.

Specifically, the outer side wall of the main sealing ring 2 may be provided with a protrusion at a position corresponding to the support body 22, so as to better match with the deformation of the support body 22 to complete sealing.

As an alternative to the primary sealing ring 2, the primary sealing ring 2 may also be of solid construction, which is intended to serve a primary sealing function, provided that a certain friction force is initially provided, so that the secondary sealing ring 3 can be compressively deformed.

As an improved embodiment of the gland ring 4, the outer side wall of the gland ring 4 protrudes outside the piston body 1 and is provided with a plurality of layers of projections 41, and the gland ring 4 has a natural state when the piston stops moving and a pressed state when the piston is pressed and radially deformed when moving. The gland ring 4 is pressed and deformed and can provide certain tightness, and when the piston shakes to incline, the gland ring can firstly contact the inner wall of the cylinder body, so that the piston body 1 is prevented from touching the cylinder body, and the function of protecting the piston body 1 is achieved. Specifically, the gland ring 4 may be made of a variable material such as rubber.

As an alternative embodiment of the gland ring 4, it may also be made of hard material, which can act as a pressure transmitting function.

As a preferred embodiment of the bidirectional sealing piston, two annular grooves 11 are formed in the side wall of the piston body 1, the two annular grooves 11 are respectively located at the end part of the piston body 1, and each annular groove 11 is internally sleeved with a main sealing ring 2, two auxiliary sealing rings 3 and two gland rings 4. The preferred structure can provide double-layer sealing, each group of sealing structures can realize bidirectional sealing, and even if one group fails, the other group can independently realize sealing, so that the reliability of the piston is improved.

It should be understood that the preferred embodiment of the piston described above is a two-way seal, and that in other embodiments the annular groove 11 may be provided with three or more annular grooves.

As an improved embodiment of the piston body 1, it comprises:

a piston main body 12;

a piston top 13 fixed to a first end of the piston body 12 by a first countersunk screw 15, and a first buffer sheet 17 is interposed between the piston top 13 and the piston body 12;

a piston bottom 14 fixed to the second end of the piston body 12 by a second countersunk screw 16, and a second buffer sheet 18 is interposed between the piston bottom 14 and the piston body 12.

According to the improved embodiment, the piston body 1 is more convenient to mount and dismount by the split structure, and the operation and maintenance difficulty is low; and buffer sheets are respectively arranged between the piston top 13 and the piston bottom 14 and between the piston main body 12, so that the piston can play a role in axial buffer when being abutted to the top or the bottom of the cylinder body, and the piston body 1 is prevented from being damaged.

Specifically, the first countersunk head screw 15 and the second countersunk head screw 16 can be set to be in a polish rod+screw rod structure, the polish rod part is close to the head part of the countersunk head screw, the top 13 or the bottom 14 of the piston is provided with a polish hole, the main body 12 of the piston is provided with a screw hole, the polish rod part of the countersunk head screw is inserted in the polish hole, and the screw rod part of the countersunk head screw is inserted in the screw hole, so that when the top 13 or the bottom 14 of the piston receives impact force, the polish rod part can be slid to fully utilize the buffering function of the buffer sheet.

Further, a protection pad 19 is fixed to both the end face of the piston top 13 away from the piston main body 12 and the end face of the piston bottom 14 away from the piston main body 12. This structure can provide further cushioning, protecting the piston body 1.

The specific material of the protection pad 19 is not limited, and may be rubber pad, silicone pad, or other deformable material.

Furthermore, the top 13 and the bottom 14 of the piston are both provided with counter bores, the head of the first countersunk head screw 15 and the head of the second countersunk head screw 16 are disposed in the counter bores, the protection pad 19 is protruded with a sealing portion 191 extending into the counter bores at the position corresponding to the first countersunk head screw 15 or the second countersunk head screw 16, and the sealing portion 191 is sleeved in the counter bores in an interference manner to seal the countersunk head screws. The structure can seal the countersunk head screw, prevent water outside the piston from entering the counter bore, lead the countersunk head screw to rust, and ensure the service life of the countersunk head screw.

Further, the piston bottom 14 has a greater weight than the piston top 13. This allows the centre of gravity of the whole piston to be lowered, which is beneficial to remain stable in motion.

Specifically, the piston bottom 14 may be made of a material having a high metal density.

Example 2

For a better understanding of the hydraulic energy storage system of this embodiment, three conventional hydraulic energy storage systems are first described:

first, underground pumped storage. The scheme is to transfer the power station to the ground and excavate the reservoir 5 in the ground. In this case, the site does not necessarily require a certain drop in the topography at the time of site selection, and the pumping and storing station can be constructed even on a flat topography. In addition, the construction under the ground can effectively reduce the influence on the surface ecology. However, the low density disadvantage of water still used as an energy storage medium is not solved. Therefore, it is still necessary to excavate the large-volume and large-drop upper and lower reservoirs 5 under the ground, and the engineering construction cost is high. So the underground pumped storage power station in the world is almost built on abandoned mine pits so as to control the construction cost. These pits, after being retrofitted, require further verification of the impact of heavy metal and other contaminants on the surrounding environment due to the need to diffuse into the water.

Second, seawater pumps and stores energy. The technology takes the ocean as the lower reservoir 5 of the pumping and storing station, so that the position of the lower reservoir 5 does not need to be considered when the site is selected. In addition, the seawater pumping and storing station is very suitable for being built on coastal areas and islands where fresh water is lacking, so that the application scene of the pumping and storing station is enlarged. However, the seawater pumped storage has the problems of seawater leakage, metal equipment corrosion, marine organism adhesion and the like which are different from the conventional pumped storage. Worldwide, only japan builds and runs through a sea water pumping and storing station in a towline, and the operation is stopped because of the problems of difficult operation and maintenance, etc. Currently, no running seawater pumped storage power station exists worldwide. In addition, sea water pumping and storage are mainly aimed at offshore areas such as coastal areas and island areas, and are not suitable for inland areas.

Third, high density fluid is pumped. According to the technical scheme, high-density fluid is used for replacing water and is used as a working medium of the pumping and storage power station, so that the volume of a unit reservoir 5 and the energy storage energy density of the unit upper and lower reservoirs 5 are improved, the whole power station is more compact in structure, and the requirements on the volume and the drop of the reservoirs 5 are particularly reduced. The high density pumping and storage technology needs to develop high density fluid, and has the problem of high cost. In addition, because special fluid is adopted, the influence on the environment, the influence on a unit and other factors are required to be fully considered, so that the technology is only in the experimental development stage at present, and no demonstration project exists in the global scope.

Based on the three hydraulic energy storage systems, the technical scheme of the embodiment is described in detail below.

An embodiment of a hydraulic energy storage system as shown in fig. 3, comprising:

a reservoir 5;

a vertical shaft 6, in which a bidirectional sealing piston is arranged, wherein the piston body 1 is coaxial with the vertical shaft 6, and the outer side wall of the main sealing ring 2 is attached to the inner wall of the vertical shaft 6;

one end of the reversible water pump turbine 7 is communicated with the reservoir 5, and the other end is communicated with the bottom of the vertical shaft 6;

and the generator set 8 is connected with the reversible water pump turbine 7 and is suitable for generating power by combining the reversible water pump turbine 7 in the energy release process.

The hydraulic energy storage system adopts the vertical shaft 6 as the cylinder body, and the system can be totally built underground except the reservoir 5, so that the system can be planned and built under various terrain conditions including platform terrains, and has lower influence on surrounding environment; the high density piston replaces the body of water to store gravitational potential energy that is much greater than the same volume of water, thus reducing the space required to construct the system.

Specifically, the reservoir 5 may be a natural lake, an existing reservoir 5, or a large-volume container.

In particular, the shaft 6 may be constructed of concrete or steel, or the like.

It is easy to understand that the reversible pump turbine 7 can be used as a water pump for pumping water; the water turbine can be used as a water turbine to convert mechanical energy of water into mechanical energy of other solids, thereby achieving the purposes of power generation and the like. The generator set 8, i.e. the structure for generating electricity by using the solid mechanical energy converted from the mechanical energy of water, may be a synchronous set or a variable speed set.

Specifically, the reversible pump turbine 7 is communicated with the upstream water reservoir 5 and the shaft 6 through a pressure steel pipe, and the pressure steel pipe is made of a material such as A3, 16Mn, or a normalized 15MnV, 15MnTi, etc. of a hot-rolled open-hearth steel or low alloy steel subjected to calm smelting.

The working process of the hydraulic energy storage system of the embodiment is as follows:

when the load of the power grid is low and energy storage of the system is needed, the reversible water pump turbine 7 operates under the working condition of the water pump, water is pumped down from the upstream water reservoir 5 to the bottom of the vertical shaft 6, so that a piston in the vertical shaft 6 rises, and electric energy on the power grid is converted into gravitational potential energy of the piston; when the load of the power grid is high, the piston at the top of the vertical shaft 6 is released, so that the piston can press the water pressure in the vertical shaft 6, and the water flows into the reversible water pump turbine 7 along the pressure steel pipe, so that the generator set 8 is pushed to rotate for power generation.

As shown in fig. 3 and 4, as a preferable number of shafts 6, a plurality of shafts 6 are provided, and the bottom of each shaft 6 is connected to the reversible pump turbine 7 through a valve 9. A plurality of, i.e., at least three. Through the setting of a plurality of shafts 6, can select 6 numbers of shaft of different quantity in a flexible way according to the demand of energy storage capacity, each shaft 6 mutually independent, the installation is convenient with dismantling, and the system is deployed easily.

Of course, the above is only a preferred number of shafts 6, and in other embodiments, only one or two shafts 6 may be provided.

Example 3

Referring to fig. 5, the present embodiment differs from embodiment 2 only in that the upstream water source is a shaft 6 portion located at the upper side of the piston.

When the system stores energy and pumps water, upper water is pumped to the lower part of the piston to lift the piston, and when the system generates electricity, lower water is pressed down and finally flows into the upper part of the piston. The scheme can realize the circulating water, can normally run only by supplementing a small amount of water with osmotic loss, does not need additional water supply of the reservoir 5, reduces the dependence on the reservoir 5, lakes and the like, and has lower limit. In addition, since water is contained in the upper piston shaft 6, it is preferable to form two annular grooves 11 in the piston body 1 to improve the sealing strength. It should be noted that each set of sealing ring sets (i.e. the combination of the structure formed by the primary sealing ring 2, the two secondary sealing rings 3 and the two gland rings 4) provides a bi-directional sealing capability, and even if one set fails, the other set can work independently, so that the two sets of sealing ring sets provide a more reliable sealing capability, while from the point of view of smooth operation of the piston, the two sets of sealing rings can avoid the problem of tilting when the piston is operated as compared with the one set.

It is apparent that the above examples are given by way of illustration only and are not limiting of the embodiments. Other variations or modifications of the above teachings will be apparent to those of ordinary skill in the art. It is not necessary here nor is it exhaustive of all embodiments. While still being apparent from variations or modifications that may be made by those skilled in the art are within the scope of the invention.

Claims

1. A bi-directional sealed piston comprising:

the piston comprises a piston body (1) which is of a columnar structure, and the side wall of the piston body is provided with at least one annular groove (11), wherein the annular groove (11) is coaxial with the piston body (1);

the main sealing ring (2) is sleeved in the annular groove (11), and the outer side wall of the main sealing ring (2) protrudes outwards from the piston body (1);

the two auxiliary sealing rings (3) are sleeved in the annular groove (11) and symmetrically distributed on two axial sides of the main sealing ring (2), the auxiliary sealing rings (3) are in contact with the main sealing ring (2), annular gaps (31) are formed in the surfaces, far away from the main sealing ring (2) in the axial direction, of the auxiliary sealing rings (3), and the auxiliary sealing rings (3) are in a natural state when the piston stops moving and in a pressed state when the piston moves and are radially deformed under pressure;

the two gland rings (4) are symmetrically distributed on two axial sides of the main sealing ring (2) and are in contact with the auxiliary sealing ring (3);

the inner side wall of the main sealing ring (2) is provided with a groove (21), a supporting body (22) is arranged in the groove (21), and the supporting body (22) has a natural state when the piston stops moving and a pressed state when the piston moves and is radially deformed under pressure;

the outer side wall of the gland ring (4) protrudes outwards from the piston body (1) and is provided with a plurality of layers of bulges (41), and the gland ring (4) has a natural state when the piston stops moving and a pressed state when the piston moves and is radially deformed under pressure.

2. The bidirectional sealing piston according to claim 1, wherein two annular grooves (11) are formed in the side wall of the piston body (1), the two annular grooves (11) are respectively located at the end part of the piston body (1), and a main sealing ring (2), two auxiliary sealing rings (3) and two gland rings (4) are sleeved in each annular groove (11).

3. The bi-directional sealed piston according to claim 1 or 2, wherein the piston body (1) comprises:

a piston body (12);

the piston top (13) is fixed at the first end of the piston main body (12) through a first countersunk head screw (15), and a first buffer sheet (17) is arranged between the piston top (13) and the piston main body (12);

the piston bottom (14) is fixed at the second end of the piston main body (12) through a second countersunk head screw (16), and a second buffer sheet (18) is arranged between the piston bottom (14) and the piston main body (12).

4. A bi-directional sealed piston according to claim 3, characterized in that the end face of the piston top (13) remote from the piston body (12) and the end face of the piston bottom (14) remote from the piston body (12) are both fixed with a protection pad (19).

5. The bidirectional sealing piston according to claim 4, wherein the piston top (13) and the piston bottom (14) are provided with counter bores, the head of the first countersunk head screw (15) and the head of the second countersunk head screw (16) are arranged in the corresponding counter bores, the part of the protection pad (19) corresponding to the first countersunk head screw (15) or the second countersunk head screw (16) is externally protruded with a sealing part (191) extending into the counter bores, and the sealing part (191) is in interference fit with the counter bores to seal the countersunk head screws.

6. A bi-directional sealed piston according to claim 3, characterized in that the piston bottom (14) has a greater weight than the piston top (13).

7. A hydraulic energy storage system, comprising:

an upstream water source;

a shaft (6) in which a bi-directional sealing piston according to any one of claims 1-6 is provided, the piston body (1) being coaxial with the shaft (6) and the outer side wall of the main sealing ring (2) being in abutment with the inner wall of the shaft (6);

one end of the reversible water pump turbine (7) is communicated with the upstream water source, and the other end of the reversible water pump turbine is communicated with the bottom of the vertical shaft (6);

the generator set (8) is connected with the reversible water pump turbine (7) and is suitable for combining the reversible water pump turbine (7) to generate power in the energy release process;

the upstream water source is an external reservoir (5) or a vertical shaft (6) part positioned on the upper side of the piston.

8. The hydraulic energy storage system according to claim 7, characterized in that the shaft (6) is provided with

And the bottom of each vertical shaft (6) is connected with the reversible water pump turbine (7) through a valve (9).