A 300mw grade compressed air energy storage unit arranged coaxially in series

Abstract

A 300MW level compressed air energy storage unit arranged coaxially in series, which relates to the technical field of compressed air energy storage.The present application is to solve the technical problems of the existing 300MW level compressed air energy storage unit, which adopts independent arrangement of compression system and expansion system, has many rotating equipment, low system integration, complex system structure, many fault points and poor operation reliability, and to overcome the defects of high initial investment, high difficulty of full life cycle operation and maintenance and high operation and maintenance cost.The present application comprises an air turbine, a first clutch, a three-in-one motor, a second clutch and a compressor unit, the three-in-one motor is arranged in the middle, the air turbine is coaxially connected in series with one end output end of the three-in-one motor through the first clutch, and the compressor unit is coaxially connected in series with the other end output end of the three-in-one motor through the second clutch.The present application is used for compressed air energy storage.

Description

Technical Field

[0001] This invention relates to the field of compressed air energy storage technology, and specifically to a 300MW-class compressed air energy storage unit arranged in coaxial series. Background Technology

[0002] Compressed air energy storage is a mainstream physical energy storage technology suitable for large-capacity, long-duration energy storage conditions. It can effectively match the long-term, large-scale energy storage application needs of power systems, and its comprehensive technical adaptability and operational advantages are significant. This technology can complete air compression energy storage during periods of surplus power and release high-pressure air to drive power generation during peak power load periods, realizing the spatiotemporal transfer and reuse of electrical energy. Its energy storage efficiency is close to that of traditional pumped hydro storage, giving it outstanding technical advantages among existing new energy storage technologies. Compared to other energy storage technologies, compressed air energy storage boasts multi-dimensional technological and application advantages: First, it has strong site adaptability, requiring no special terrain and suitable for various construction scenarios with fewer deployment constraints; second, it has a short construction cycle, high engineering standardization, and superior implementation efficiency compared to pumped storage; third, it offers excellent operational safety and environmental adaptability, generating no pollutants or carbon emissions during operation, resulting in minimal disturbance to the surrounding environment; fourth, it has a complete supporting technology system, with mature domestically produced core equipment and a solid foundation for technological iteration and engineering implementation; and fifth, it has a long service life, with a unit lifespan exceeding 30 years and significantly better operational stability than conventional electrochemical energy storage. Furthermore, during operation, this unit can provide stable rotational inertia to the power system, effectively compensating for the technical shortcoming of insufficient rotational inertia in new energy grid-connected systems and ensuring grid voltage and frequency stability. In addition, compressed air energy storage units can take into account multiple functions such as system peak shaving, frequency regulation, phase regulation and backup start-up and shutdown. They can not only smooth out the power system's day and night and seasonal power fluctuations, but also quickly respond to short-term power disturbances in the power grid. They have outstanding adaptability to multiple scenarios and have good technical application and promotion value.

[0003] With the continuous iteration and maturation of compressed air energy storage technology, 300MW-class units have achieved large-scale engineering applications and are currently the mainstream engineering models in the field of large-capacity compressed air energy storage. The current common and mature design for this class of units adopts an architecture of dual-row parallel compression systems and a single-row expansion system. The compression power system and the expansion power generation system operate independently and separately, resulting in a distributed overall system architecture. In terms of equipment configuration, this model typically features 6-8 compressors and matching drive motors, along with one air turbine and one main generator, for a total of 14-18 rotating core devices. This traditional layout architecture has inherent technical defects and application shortcomings: On the one hand, the large number and dispersed arrangement of rotating equipment in the unit result in low system integration and unification. The complex structure of pipeline connections and electrical control links between equipment significantly increases the complexity of the system structure, leading to numerous equipment failure points and a high probability of linkage failure, directly affecting the overall operational reliability and stability of the unit. On the other hand, the dispersed arrangement of multiple devices not only increases the initial construction costs of equipment procurement, civil engineering, and pipeline laying, but also increases the difficulty of daily inspection, fault diagnosis, and equipment maintenance due to the complex system structure and large number of devices. This results in high operation and maintenance costs throughout the entire life cycle of the unit, hindering the low-cost, large-scale promotion and application of large-capacity compressed air energy storage technology. Summary of the Invention

[0004] This invention addresses the technical problems of existing 300MW-class compressed air energy storage units, which suffer from complex system structure, numerous fault points, and poor operational reliability due to the separate and independent arrangement of the compression and expansion systems, the large number of rotating devices, and the low system integration. Furthermore, to overcome the shortcomings of existing units, such as high initial investment, difficult operation and maintenance throughout the entire life cycle, and high operation and maintenance costs, this invention proposes a 300MW-class compressed air energy storage unit with a coaxial series arrangement.

[0005] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows:

[0006] A 300MW-class compressed air energy storage unit with coaxial series arrangement includes an air turbine, a first clutch, a three-in-one motor, a second clutch, and a compressor unit. The three-in-one motor is located in the middle. The air turbine is coaxially connected in series with one end of the three-in-one motor through the first clutch. The compressor unit is coaxially connected in series with the other end of the three-in-one motor through the second clutch.

[0007] Furthermore, the compressor unit includes a first-stage compressor, a second-stage compressor, and a third-stage compressor connected coaxially in series from first to last.

[0008] Furthermore, the compressed air energy storage unit can switch between three operating modes—energy storage, power generation, and phase regulation—by disengaging and engaging the first and second clutches.

[0009] Furthermore, during energy storage operation, the first clutch disengages and the second clutch engages, and the three-in-one motor drives the first-stage compressor, the second-stage compressor, and the third-stage compressor to compress air for energy storage.

[0010] Furthermore, during power generation, the first clutch engages, the second clutch disengages, and the three-in-one motor acts as a generator, with the air turbine driving the three-in-one motor to generate electricity.

[0011] Furthermore, during phase-shifting operation, both the first and second clutches disengage, and the three-in-one motor operates independently as the phase shifter.

[0012] Furthermore, both the first clutch and the second clutch are gear-type controllable clutches, and the first clutch and the second clutch are arranged opposite to each other. The output ends of the first clutch and the second clutch are connected to the output end of the three-in-one motor through flanges.

[0013] Furthermore, it also includes a sliding pin system, which allows the compressed air energy storage unit to expand smoothly under different operating conditions.

[0014] Furthermore, the sliding pin system includes a rotor expansion system and a stator expansion system.

[0015] Furthermore, the rotor expansion system includes the axial expansion of the air turbine rotor, the three-in-one motor rotor, and the compressor unit rotor, and the stator expansion system includes the axial expansion of the three-in-one motor stator.

[0016] The beneficial effects of this invention compared to the prior art are:

[0017] This application presents an innovative invention: a single-row coaxial arrangement scheme for 300MW-class compressed air energy storage equipment. This scheme will significantly reduce the complexity of 300MW-class compressed air energy storage systems, lower initial investment and subsequent operation and maintenance costs for energy storage power plants, and enable flexible switching between multiple operating conditions, including energy storage, power generation, and phase regulation. It will have a revolutionary impact on the future compressed air energy storage equipment market, driving the energy revolution and the construction of new power systems. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of a 300MW-class compressed air energy storage unit arranged in coaxial series according to the present invention.

[0019] Figure 2 This is a schematic diagram of the sliding pin system of a 300MW-class compressed air energy storage unit arranged in coaxial series according to the present invention;

[0020] Figure 3 This is a schematic diagram of the sliding pin system of the air turbine in this invention;

[0021] Figure 4This is a schematic diagram of the sliding pin system of the three-in-one motor in this invention;

[0022] Figure 5 This is a schematic diagram of the sliding pin system of the first-stage compressor and the second-stage compressor in this invention;

[0023] Figure 6 This is a schematic diagram of the sliding pin system of the three-stage compressor in this invention.

[0024] In the diagram: 101 - Air turbine; 11 - First clutch; 102 - Three-in-one motor; 15 - Second clutch; 103 - First stage compressor; 104 - Second stage compressor; 105 - Third stage compressor;

[0025] 1-1# Bearing housing; 2-1# Centering beam; 3- Turbine high and medium pressure cylinder; 4- Turbine high and medium pressure rotor; 5-2# Centering beam; 6-1# Thrust bearing; 7-2# Bearing housing; 8- Turbine low pressure cylinder; 9- Turbine low pressure rotor; 10-3# Bearing housing; 11- Clutch 1; 12-2# Thrust bearing; 13- Three-in-one motor stator; 14- Three-in-one motor rotor; 15- Clutch 2; 16-4# Bearing housing; 17- Self-lubricating 18-Positioning key; 19-First stage compressor cylinder; 20-First stage compressor rotor; 21-Thrust bearing #3; 22-Rigid coupling; 23-Bearing housing #5; 24-Centering beam #3; 25-Second stage compressor cylinder; 26-Second stage compressor rotor; 27-Centering beam #4; 28-Bearing housing #6; 29-Flexible coupling; 30-Thrust bearing #4; 31-Third stage compressor cylinder; 32-Third stage compressor rotor. Detailed Implementation

[0026] To make the technical problems solved, the technical solutions, and the beneficial effects of the present invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention.

[0027] Specific implementation method one: Combining Figures 1 to 6 This embodiment describes a 300MW-class compressed air energy storage unit arranged coaxially in series, comprising an air turbine 101, a first clutch 11, a three-in-one motor 102, a second clutch 15, and a compressor unit. The three-in-one motor 102 is located in the middle. The air turbine 101 is coaxially connected in series with one output end of the three-in-one motor 102 through the first clutch 11. The compressor unit is coaxially connected in series with the other output end of the three-in-one motor 102 through the second clutch 15.

[0028] Specific Implementation Method Two: Combining Figures 1 to 6This embodiment describes a compressor unit comprising a first-stage compressor 103, a second-stage compressor 104, and a third-stage compressor 105 connected in series coaxially from first to last.

[0029] The undisclosed technical features in this embodiment are the same as those in Specific Embodiment 1.

[0030] Specific implementation method three: Combining Figures 1 to 6 This embodiment describes a compressed air energy storage unit that can switch between three operating modes—energy storage, power generation, and phase regulation—by disengaging and engaging the first clutch 11 and the second clutch 15.

[0031] The undisclosed technical features in this embodiment are the same as those in Specific Embodiment Two.

[0032] Specific implementation method four: Combination Figures 1 to 6 In this embodiment, during the energy storage operation, the first clutch 11 is disengaged, the second clutch 15 is engaged, and the three-in-one motor 102 drives the first-stage compressor 103, the second-stage compressor 104, and the third-stage compressor 105 to compress air for energy storage.

[0033] The undisclosed technical features in this embodiment are the same as those in Specific Embodiment Three.

[0034] Specific Implementation Method Five: Combining Figures 1 to 6 In this embodiment, during the power generation operation, the first clutch 11 is engaged, the second clutch 15 is disengaged, the three-in-one motor 102 acts as a generator, and the air turbine 101 drives the three-in-one motor 102 to generate electricity.

[0035] The undisclosed technical features in this embodiment are the same as those in Specific Embodiment Three.

[0036] Specific Implementation Method Six: Combination Figures 1 to 6 In this embodiment, during the phase-shifting operation, both the first clutch 11 and the second clutch 15 are disengaged, and the three-in-one motor 102 operates independently as a phase shifter.

[0037] The undisclosed technical features in this embodiment are the same as those in Specific Embodiment Three.

[0038] Specific implementation method seven: Combination Figures 1 to 6 In this embodiment, both the first clutch 11 and the second clutch 15 are gear-type controllable clutches. The first clutch 11 and the second clutch 15 are arranged opposite to each other. The output ends of the first clutch 11 and the second clutch 15 are connected to the output end of the three-in-one motor 102 through flanges.

[0039] The undisclosed technical features in this embodiment are the same as those in specific embodiments four, five, or six.

[0040] Both the first clutch 11 and the second clutch 15 are gear-type controllable clutches, which can absorb a maximum axial expansion of 50mm, effectively ensuring the safety of the unit's shaft system. The first clutch 11 and the second clutch 15 are arranged opposite each other, and their output ends are installed on the flanges at both ends of the three-in-one motor 102 to reduce the cantilever weight of the rotor of the three-in-one motor 102 when the clutches are disengaged, thereby improving the rigidity of the shaft system.

[0041] Specific implementation method eight: Combination Figures 1 to 6 This embodiment also includes a sliding pin system, which allows the compressed air energy storage unit to expand smoothly under different operating conditions.

[0042] The undisclosed technical features in this embodiment are the same as those in Specific Embodiment 1.

[0043] Because the single-row coaxial arrangement of 300MW-class compressed air energy storage equipment has a long shaft system, a sliding pin system is designed for this scheme to ensure smooth expansion of the unit under different operating conditions and safe and stable shaft system.

[0044] Specific Implementation Method Nine: Combining Figures 1 to 6 This embodiment describes a sliding pin system that includes a rotor expansion system and a stator expansion system.

[0045] The undisclosed technical features in this embodiment are the same as those in specific embodiment eight.

[0046] Specific Implementation Method Ten: Combining Figures 1 to 6 This embodiment describes the rotor expansion system, which includes the axial expansion of the air turbine rotor 101, the three-in-one motor rotor 102, and the compressor unit rotor. The stator expansion system includes the axial expansion of the three-in-one motor stator 102.

[0047] The undisclosed technical features in this embodiment are the same as those in specific embodiment nine.

[0048] In the rotor expansion system:

[0049] The rotor expands outwards from the four thrust bearings as dead points. The turbine's #1 thrust bearing 6 is housed within the #2 bearing housing 7. During rotor expansion, it expands towards both the turbine's high-pressure cylinder 3 and the three-in-one motor 102. Positioning the #1 thrust bearing 6 in the middle prevents excessive expansion on one side, thus avoiding dynamic and static friction. Since both ends of the three-in-one motor 102 are connected to equipment, a #2 thrust bearing 12 is used for positioning to prevent the rotor from oscillating back and forth. The three-in-one motor rotor 14 expands towards both the turbine and compressor sides from the #2 thrust bearing as the dead point. Expansion between the turbine rotor and the three-in-one motor rotor 14 is absorbed by the first clutch 11, while expansion between the compressor rotor 20 and the three-in-one motor rotor 14 is absorbed by the second clutch 15. The thrust bearing 21 of the first-stage compressor 103 is located on the intake side, while the second-stage compressor 104 does not have a thrust bearing. The rotors 20 and 26 of the first-stage compressor are connected as a whole by a rigid coupling 22. When the rotors expand, with the thrust bearing 21 of the first-stage compressor 103 as the dead point, they expand towards the three-in-one motor 102 and the third-stage compressor 105 respectively. The thrust bearing 30 of the third-stage compressor 105 is located at the outlet end. The rotor 32 of the third-stage compressor expands towards the second-stage compressor 104 and the intake side with the thrust bearing 30 as the dead point. The expansion between the rotors 26 and 32 of the second-stage compressor is absorbed by the flexible coupling 29. The position of the thrust bearing 30 is close to the flexible coupling 29, which can effectively reduce the amount of expansion towards the coupling side, making the structural design more reasonable. If a rigid coupling is used, the axial expansion of the three-stage compressor 105 will be very large due to the excessive length of the shaft system. The dynamic and static clearances of the compressor need to be set very large, which will further increase the shaft length, increasing the design difficulty of the compressor and the instability of the shaft system.

[0050] In a stator expansion system:

[0051] In the air turbine 102, bearing housing 7 (2#), low-pressure cylinder 8, and bearing housing 10 (3#) are all fixed to the base frame with independent dead points. The high-pressure cylinder 3 is connected to bearing housing 1 (1#) and bearing housing 7 (2#) as a whole through centering beam 2 (3#) and centering beam 5 (2#). Bearing housing 1 (1#) is connected to the base frame by a longitudinal positioning key. The bearing housing can slide on the base frame. When the unit expands, the high-pressure cylinder 3 pushes bearing housing 1 (1#) to slide axially on the base frame. The low-pressure cylinder 8 expands from the center to both sides.

[0052] In the three-in-one motor 102, the stator 13 of the three-in-one motor is fixed to the foundation, and when it expands, it expands from the center to both sides.

[0053] In the first-stage compressor 103, the first-stage compressor cylinder 19 is fixed to the foundation with a dead point, and the #4 bearing housing 16 is fixed to the base frame with an independent dead point. The #4 bearing housing 16 and the first-stage compressor cylinder 19 are positioned by a key. Self-lubricating metal gaskets are added to the support surfaces of the cylinder claw and the #4 bearing housing 16. When the unit expands, the first-stage compressor cylinder 19 expands to both sides with the dead point as the center. The cylinder claw slides on the #4 bearing housing 16. The key ensures that the centers of the #4 bearing housing 16 and the first-stage compressor cylinder 19 are aligned.

[0054] In the two-stage compressor 104, bearing housing 23 (#5) is fixed to the foundation at a dead point, while bearing housing 28 (#6) is a sliding housing. The two-stage compressor cylinder 25 is connected to bearing housings 23 (#5) and 28 (#6) by centering beams 24 (#3) and 27 (#4), forming a single unit. During unit expansion, the two-stage compressor cylinder 25 pushes bearing housing 28 to slide axially on the base frame. Bearing housing 28 and the base frame are also positioned using a longitudinal key.

[0055] In the three-stage compressor 105, the bearing housing and cylinder of the three-stage compressor are integrated. The cylinder 31 of the three-stage compressor is set with a dead point biased towards the outlet side. When the unit expands, it expands to both sides with the dead point as the center.

[0056] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A 300MW-class compressed air energy storage unit arranged coaxially in series, characterized in that: It includes an air turbine (101), a first clutch (11), a three-in-one motor (102), a second clutch (15), and a compressor unit. The three-in-one motor (102) is located in the middle. The air turbine (101) is coaxially connected in series with one end of the output terminal of the three-in-one motor (102) through the first clutch (11). The compressor unit is coaxially connected in series with the other end of the output terminal of the three-in-one motor (102) through the second clutch (15).

2. A 300MW-class compressed air energy storage unit arranged in coaxial series according to claim 1, characterized in that: The compressor unit includes a first-stage compressor (103), a second-stage compressor (104), and a third-stage compressor (105) connected in series coaxially from first to last.

3. A 300MW-class compressed air energy storage unit arranged in coaxial series according to claim 2, characterized in that: The compressed air energy storage unit can switch between three operating conditions: energy storage, power generation, and phase regulation by disengaging and engaging the first clutch (11) and the second clutch (15).

4. A 300MW-class compressed air energy storage unit arranged in coaxial series according to claim 3, characterized in that: During energy storage operation, the first clutch (11) disengages and the second clutch (15) engages. The three-in-one motor (102) drives the first-stage compressor (103), the second-stage compressor (104), and the third-stage compressor (105) to compress air for energy storage.

5. A 300MW-class compressed air energy storage unit arranged in coaxial series according to claim 3, characterized in that: When the generator is in operation, the first clutch (11) is engaged and the second clutch (15) is disengaged. The three-in-one motor (102) acts as a generator, and the air turbine (101) drives the three-in-one motor (102) to generate electricity.

6. A 300MW-class compressed air energy storage unit arranged in coaxial series according to claim 3, characterized in that: During phase adjustment, the first clutch (11) and the second clutch (15) are both disengaged, and the three-in-one motor (102) works independently as a phase adjuster.

7. A 300MW-class compressed air energy storage unit arranged in coaxial series according to claim 4, 5 or 6, characterized in that: The first clutch (11) and the second clutch (15) are both gear-type controllable clutches. The first clutch (11) and the second clutch (15) are arranged opposite to each other. The output ends of the first clutch (11) and the second clutch (15) are connected to the output end of the three-in-one motor (102) through flanges.

8. A 300MW-class compressed air energy storage unit arranged in coaxial series according to claim 1, characterized in that: It also includes a sliding pin system, which allows the compressed air energy storage unit to expand smoothly under different operating conditions.

9. A 300MW-class compressed air energy storage unit arranged in coaxial series according to claim 8, characterized in that: The sliding pin system includes a rotor expansion system and a stator expansion system.

10. A 300MW-class compressed air energy storage unit arranged in coaxial series according to claim 9, characterized in that: The rotor expansion system includes the axial expansion of the air turbine (101) rotor, the three-in-one motor (102) rotor and the compressor unit rotor, and the stator expansion system includes the axial expansion of the three-in-one motor (102) stator.

Images