Multi-stage expansion machine shafting configuration structure of high-power compressed air energy storage system and application of multi-stage expansion machine shafting configuration structure

Abstract

The invention discloses a multi-stage expansion machine shafting configuration structure of a high-power compressed air energy storage system and application. The multi-stage expansion machine shafting configuration structure is suitable for efficient energy release and dynamic power adjustment in the multi-stage expansion process under the sliding pressure operation condition. The structure comprises a high-pressure gas storage tank, a plurality of turbine expansion sections, a generator and at least one controllable clutch device, and dynamic connection or disconnection between the specific expansion sections and a main shaft system can be achieved according to gas storage pressure attenuation and system load changes. A heat exchanger is arranged in front of an air inlet path of each expansion section, and the system is matched with a plurality of control valves to adjust air flow on-off and path switching. By monitoring pressure and load parameters, the states of a target expansion section and a heat exchanger thereof are controlled, and idling section bypass, heat source closing and system heat efficiency optimization are achieved. The system has the advantages of flexible structure, quick response, efficient operation and the like, and is suitable for engineering integration application of a multi-working-condition adaptive high-power compressed air energy storage system.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of compressed air energy storage, and particularly relates to a multi-stage expander shaft configuration structure of a large-power compressed air energy storage system and application. The dynamic adjustment of the cascade configuration of the expansion section by a controllable clutch device reduces the air blowing effect, improves the efficiency of the expander and the response speed of the rotor, and is particularly suitable for efficient wide operating condition operation in the sliding pressure energy release process. BACKGROUND

[0002] The global energy structure is accelerating the transformation to renewable energy, and new energy such as wind and solar energy is developing rapidly. However, these energy sources are intermittent and volatile, and need to be balanced through energy storage technology. Energy storage systems can effectively improve the efficiency, safety and economy of power systems through functions such as "peak clipping and valley filling", frequency and pressure regulation, and become the core support of new power systems. Compressed air energy storage is one of the important technical directions in the field of long-time energy storage due to its large scale, long service life and environmental friendliness.

[0003] In a compressed air energy storage system, the expander converts high-pressure air energy into mechanical energy to drive the generator to generate electricity through multi-stage expansion. In the prior art, the multi-stage expander shaft usually adopts a single shaft hard connection structure, and all expansion stages (ultra-high pressure, high pressure, medium pressure, and low pressure) are fixedly connected with the generator rotor. This structure has the advantages of compact mechanical structure and mature manufacturing process, but in the sliding pressure operation process, as the gas storage pressure gradually decreases, the intake pressure of the front expansion stage (such as the ultra-high pressure stage) is reduced to the point where it cannot effectively output power, and the shaft still idles, resulting in significant idle loss, air blowing loss and temperature rise problems, reducing system efficiency. In addition, the low-pressure expansion stage also has idle loss under low-load conditions, and the single shaft hard connection shaft has large inertia, resulting in slow start speed and delayed control response. For example, Chinese patent CN107514294B discloses a combined compressed air energy storage system, which sets a clutch between the high and low pressure compressor units and the expander unit to realize separate or combined operation of the units under different operating conditions. However, this scheme mainly focuses on the overall regulation and control of the compression and expansion processes, and does not consider the dynamic optimization of the internal expansion stages of the expander shaft, making it difficult to finely solve the idle loss problem.

[0004] Furthermore, as the power level of the expander unit continues to increase, the multi-stage rigid connection structure can cause complex mechanical stress distribution and shaft torsional vibration problems during operation, increasing the design difficulty and operation and maintenance pressure of the equipment, and limiting the scale and modular development of the system. At the same time, the traditional expander shaft configuration method generally lacks flexibility and cannot be dynamically adjusted according to real-time gas source pressure, system load or operating state, making it difficult to meet the dual demands of high efficiency and energy saving and wide operating condition adaptability.

[0005] In summary, the rigid connection structure of the multi-stage expander in the existing compressed air energy storage system has obvious deficiencies in improving system efficiency, dynamic response capability and adapting to variable operating conditions. Therefore, how to realize flexible connection and efficient collaborative control between multiple expansion sections to reduce idling loss, improve energy conversion efficiency and enhance system operation adaptability is a technical problem to be solved. SUMMARY

[0006] (I) Invention purposes

[0007] Based on the above status quo, the present application aims to provide a high-power multi-stage expander shaft configuration structure and application. By introducing a controllable clutch device between multiple expansion sections, combined with real-time monitoring of system operating pressure and load parameters, dynamic connection and disconnection control of specific expansion sections and the main shaft system is realized, and the gas inlet and outlet paths and heat exchange system state of the corresponding expansion section are adjusted collaboratively, thereby effectively avoiding the air blowing loss and energy waste caused by the idling of the expansion section, and improving the response speed of the turbine expander rotor, meeting the efficient and wide operating condition requirements of the high-power grade expander unit during the sliding pressure process.

[0008] (II) Technical solutions

[0009] To achieve the purposes of the application and solve its technical problems, the application adopts the following technical solutions:

[0010] The first purpose of the present application is to provide a high-power compressed air energy storage system multi-stage expander shaft configuration structure for realizing selective participation of part of the expansion sections according to the storage pressure decay and system load change, thereby reducing idling loss and air blowing loss, improving shaft response speed and system energy efficiency, and adapting to the wide operating condition dynamic operation requirements of the high-power compressed air energy storage system during the sliding pressure process, comprising a high-pressure gas storage tank, multiple turbine expansion sections, and a generator, wherein:

[0011] The shaft configuration structure further comprises at least one controllable clutch device for dynamically connecting the target expansion section rotor and the main shaft system. The main shaft system is composed of part or all of the rotors in the super-high pressure, high pressure, medium-high pressure, medium pressure, and low pressure expansion sections connected in sequence by the high-pressure gas storage tank and the generator hard connection, and each turbine expansion section is provided with a corresponding pre-expansion section heat exchanger on the gas inlet pipeline for heating the high-pressure air entering each turbine expansion section.

[0012] The controllable clutch device is arranged between the main shaft system and the target expansion section, the target expansion section is one or more expansion sections that are prone to energy loss and efficiency reduction under the preset working condition due to deviation of intake parameters or load demand from the design point, by setting the pressure and / or load operation parameter threshold, and according to the real-time pressure and / or unit load parameter in the system operation, the controllable clutch device is dynamically triggered to adjust the connection or disconnection of the target expansion section and the main shaft system;

[0013] The shaft system configuration structure is also provided with a plurality of control valves for cooperating with the controllable clutch device and controlling the intake and exhaust of the target expansion section; the high-pressure gas in the high-pressure gas tank is sequentially expanded by all or part of the ultrahigh-pressure, high-pressure, medium-pressure and low-pressure expansion sections, and the high-pressure air passing through each expansion section is heated by the heat exchanger; and when the controllable clutch device is triggered to be connected or disconnected, the heat exchanger cooling system of the target expansion section is synchronously opened or closed.

[0014] The second application object of the present application is to provide a large-power compressed air energy storage system comprising the above-mentioned expansion machine shaft system configuration structure.

[0015] (Three) Technical effects

[0016] Compared with the prior art, the large-power multi-stage expansion machine unit shaft system configuration of the present application has the following beneficial and significant technical effects: (1) based on the shaft system adjustment characteristics of the controllable clutch device, the cascade combination of the expansion sections is dynamically adjusted according to the operating condition, the idle loss of part of the expansion sections is reduced, the slip pressure operation efficiency of the turbine expansion machine is improved, and the rotor response speed is improved, which meets the high-efficiency wide-condition operation demand of the large-power energy storage system; (2) the idle loss of one or more expansion sections is reduced, the problem of air blowing loss or excessively high air blowing temperature is avoided, and the overall efficiency and unit operation safety of the system are improved; (3) the start-up speed is improved by dynamically adjusting the shaft system inertia, so that the speed control response is faster and more accurate; (4) the present application supports modular expansion and has strong adaptability, and as the power of the expansion machine generator set is further increased, it can adapt to different power and air volume demands. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 The shaft system configuration structure schematic diagram for example 1 (single low-pressure expansion section configuration, and ultrahigh-pressure expansion section T0 can be disconnected);

[0018] Figure 2 The shaft system configuration structure schematic diagram for example 2 (single low-pressure expansion section T4 can be disconnected);

[0019] Figure 3 The shaft system configuration structure schematic diagram for example 3 (double low-pressure expansion section configuration, and ultrahigh-pressure expansion section T0 can be disconnected);

[0020] Figure 4 Figure 1 is a schematic diagram of the shaft train configuration of Example 1 (single low-pressure expansion section T4).

[0021] Legend: ST-high pressure gas storage tank; G-generator; GB-gear box; CP1-first controllable clutch device; CP2-second controllable clutch device; T0-ultra-high pressure expansion section; T1-high pressure expansion section; T2-medium-high pressure expansion section; T3-medium pressure expansion section; T4-single low pressure expansion section; T41-first low pressure expansion section; T42-second low pressure expansion section; HT0-ultra-high pressure expansion section pre-heat exchanger; HT1-high pressure expansion section pre-heat exchanger; HT2-medium-high pressure expansion section pre-heat exchanger; HT3-medium pressure expansion section pre-heat exchanger; HT4-low pressure expansion section pre-heat exchanger; HT41-first low pressure expansion section pre-heat exchanger; HT42-second low pressure expansion section pre-heat exchanger; V1-V4 first to fourth control valves. DETAILED DESCRIPTION

[0022] The present application aims to provide a large-power multi-stage expansion machine shaft train configuration structure, by introducing controllable clutch devices between multiple expansion sections, for realizing selective participation of partial expansion sections according to gas storage pressure decay and system load changes, thereby reducing idling loss and air blowing loss, improving shaft train response speed and overall energy efficiency, and adapting to wide operating condition dynamic operation requirements of large-power compressed air energy storage systems in the sliding pressure process. In order to make the purpose, technical scheme and advantages of the present application clearer, the technical scheme of the embodiments of the present application will be described in more detail below in combination with the drawings in the embodiments of the present application.

[0023] Example 1: Expansion machine shaft train configuration structure

[0024] As shown in Figures 1 to 4 The large-power compressed air energy storage system multi-stage expansion machine shaft train configuration structure provided by the embodiments of the present application mainly includes a high-pressure gas storage tank ST, multiple turbine expansion sections T0-T4, multiple expansion section pre-heat exchangers HT0-HT4, multiple control valves V1-V4, a generator G, a gear box GB, and a controllable clutch device CP1. The controllable clutch device CP1 is used to dynamically connect the target expansion section rotor and the main shaft train, the main shaft train is composed of part or all of the rotors in the ultra-high pressure, high pressure, medium-high pressure, medium pressure, and low pressure expansion sections connected in sequence by the high-pressure gas storage tank ST and the generator G, and each turbine expansion section T0-T4 is provided with a corresponding expansion section pre-heat exchanger HT0-HT4 on the inlet pipeline, for heating the high-pressure air entering each turbine expansion section.

[0025] The controllable clutch device CP1 is arranged between the main shaft system and the target expansion section rotor. The target expansion section is one or more expansion sections that are prone to energy loss and efficiency reduction under the preset working conditions due to deviation of intake parameters or load demand from the design point. By setting pressure and / or load operation parameter thresholds and according to real-time pressure and / or unit load parameters in system operation, the controllable clutch device is triggered to adjust the connection or disconnection of the target expansion section and the main shaft system.

[0026] The shaft system configuration structure is also provided with a plurality of control valves V1-V4 for cooperating with the controllable clutch device CP1 and controlling the intake and exhaust of the target expansion section. The high-pressure gas in the high-pressure gas tank ST is sequentially expanded through all or part of the ultra-high-pressure, high-pressure, medium-pressure and low-pressure expansion sections. The high-pressure air passing through each expansion section is heated by the heat exchanger. When the controllable clutch device is triggered to connect or disconnect, the heat exchanger cooling system of the target expansion section is simultaneously opened or closed.

[0027] As a preferred embodiment, a gear box GB is selectively arranged between the main shaft system and the target expansion section rotor. The gear box GB is flexibly selected as a single-stage reduction, double-stage compound reduction or variable-ratio reduction transmission structure according to the matching relationship between the optimal design speed of the target expansion section and the speed range of the main shaft system and the clutch, so as to mechanically match the optimal design speed of the target expansion section with the actual speed range of the main shaft system in the connected state of the controllable clutch device CP1, to ensure that the target expansion section can stably operate in its high-efficiency working speed range when connected to the main shaft system, to avoid energy loss, mechanical impact or structural fatigue problems caused by speed mismatch, and to improve the safety and reliability of the shaft system linkage.

[0028] As a preferred embodiment, the shaft system configuration structure further includes an operating state control unit that cooperates with the controllable clutch device and the control valves to monitor the intake pressure of the target expansion section and / or the unit load operation parameter in real time. When the intake pressure of the target expansion section is stably higher than the set pressure threshold or the unit load is stably higher than the set load threshold, the controllable clutch device is in the connected state, the mechanical connection between the target expansion section rotor and the main shaft system is maintained, and all the expansion sections normally work. When the relevant operating state parameters continuously decrease and are stably lower than the set threshold, the disconnection action is performed to mechanically separate the target expansion section rotor from the main shaft system and stop the rotation, and the control valves are adjusted to make the high-pressure gas bypass the target expansion section and continue to work in the subsequent expansion section.

[0029] As a preferred embodiment, the action control strategy of the controllable clutch device CP1 includes hierarchical threshold control and hysteresis control logic. The connection threshold and the disconnection threshold are set, and the connection threshold is higher than the disconnection threshold to form a hysteresis characteristic. When the operating parameter is lower than the disconnection threshold, the disconnection action is triggered. When the operating parameter recovers and is stably higher than the connection threshold, the connection action is triggered, to avoid frequent switching of the clutch near the threshold.

[0030] Preferably, the shaft system configuration also includes a heat exchanger control unit that works in conjunction with the controllable clutch device CP1. When the controllable clutch device CP1 triggers a disengagement action to separate the target expansion section rotor from the main shaft system, the heat exchanger before the expansion section corresponding to the target expansion section is simultaneously shut down to stop the heating treatment of the target expansion section. When the controllable clutch device CP1 triggers a connection action to re-establish the mechanical connection, the heat exchanger before the expansion section corresponding to the target expansion section is simultaneously turned on to resume the heating treatment of the high-pressure air entering the target expansion section, thereby realizing coordinated control of energy management and expansion section operating status.

[0031] The core of this invention is: based on the pressure and load changes during operation, a controllable clutch device is used to dynamically connect one or more specific expansion sections with the main shaft system. Combined with valve control of the airflow path, flexible connection or disconnection of some expansion sections is achieved, avoiding airflow loss of one or more expansion sections and improving the rotor response speed of the expander.

[0032] Example 2: Single low-pressure expansion section configuration with detachable ultra-high pressure expansion section T0

[0033] Based on the expander shaft configuration structure described in Embodiment 1 above, this embodiment further provides a typical configuration method with the ultra-high pressure expansion section T0 as the target expansion section, which is suitable for the system to achieve automatic disconnection of the front-end expansion section and energy efficiency optimization control when the operating pressure of the high pressure section drops below the critical threshold.

[0034] like Figure 1 As shown, in this embodiment 2, the target expansion section is set as the ultra-high pressure expansion section T0 connected to the high pressure gas storage tank ST. The rotor of the ultra-high pressure expansion section T0 is connected to the rotor of the high pressure expansion section T1 through the gearbox GB and the controllable clutch device CP1. The gearbox GB can be flexibly selected according to whether the optimal design speed of the T0 section is consistent with the working range of the main shaft and the clutch speed. The connection and disengagement of the controllable clutch device CP1 is triggered by the intake pressure of the ultra-high pressure expansion section and controlled by the pressure threshold. The generator G is located on one side of the rotor of the low pressure expansion section T4 and is rigidly connected to the rotors of the main expansion sections T1-T4.

[0035] At least three control valves are installed in the connecting pipeline. The first control valve V1 is located before the heat exchanger T0 in the ultra-high pressure expansion section, the second control valve V2 is located at the outlet of the exhaust section of the ultra-high pressure expansion section T0, and the third control valve V3 is located before the intersection of the inlet section of the high pressure expansion section T1 and the outlet section of the ultra-high pressure expansion section T0.

[0036] In the initial state of the system, the pressure of the high-pressure gas storage tank ST is higher than the set pressure threshold P1. The controllable clutch device CP1 is connected, the first and second control valves V1 and V2 are opened, the third control valve V3 is closed, all heat exchangers before the expansion section are put into operation, and the entire section is cascaded. After the high-pressure gas passes through the ultra-high pressure expansion section T0, it passes through the subsequent expansion sections T1-T4 in sequence to do work.

[0037] During system operation, the inlet pressure of the ultra-high pressure expansion section T0 is monitored in real time. If it remains below the set threshold P1, it is determined that the expansion section has lost its effective expansion capacity. The control system will then execute the following disengagement strategy: close the first and second control valves V1 and V2 and trigger the clutch CP1 disengagement signal to stop the rotor of the ultra-high pressure expansion section T0 from rotating. Close the heat exchanger HT0 before its airflow inlet to avoid ineffective heating loss. At the same time, open the third control valve V3 to allow the high-pressure gas in the gas storage tank to bypass the target expansion section and enter the high-pressure expansion section T1 through the bypass to continue expanding and doing work. This effectively avoids the blower loss and system energy efficiency reduction caused by the idling of the ultra-high pressure expansion section T0.

[0038] Example 3: Single low-pressure expansion section T4 can be detached

[0039] Based on the expander shaft system configuration structure described in Embodiment 1 above, this embodiment further provides a shaft system configuration method with the low-pressure expansion section T4 as the target expansion section. This method is suitable for application scenarios where the final expansion section is disconnected first when the system is in a low-load operating state in order to reduce idling losses and optimize energy utilization efficiency.

[0040] like Figure 2 As shown, in this embodiment 3, the target expansion section is the low-pressure expansion section T4. The rotor of the low-pressure expansion section T4 is connected to the rotor of the medium-pressure expansion section T3 through the gearbox GB and the controllable clutch device CP1. The gearbox GB can be flexibly selected according to whether the optimal design speed of the low-pressure expansion section T4 is consistent with the working range of the main shaft and clutch speed. The connection and disengagement of the controllable clutch device CP1 is controlled by the pressure threshold and is used to disengage the rotor of section T4 under low load conditions to avoid inefficient idling operation. Its connection and disengagement action is triggered by the unit load. The generator G is located on the side of the ultra-high pressure rotor T0 and is rigidly connected to the rotor of the main expansion section T0-T3.

[0041] At least three control valves are installed in the connecting pipeline. The first control valve V1 is located before the heat exchanger HT0 in the ultra-high pressure expansion section. The second control valve V2 is located on the exhaust pipeline of the T3D in the medium pressure expansion section and is connected to the atmosphere. The third control valve V3 is located before the heat exchanger HT4 in the low pressure expansion section.

[0042] Real-time monitoring of the unit load, when the unit load is lower than the set load threshold, the control system performs the following disengagement operation: the low-pressure expansion section T4 is disengaged by the controllable clutch device CP1, the second control valve V2 is opened, the third control valve V3 is closed to cut off the gas flow supply to the low-pressure expansion section T4, the low-pressure expansion section front heat exchanger HT4 is closed, and the exhaust gas of the medium-pressure expansion section T3 is directly discharged to the atmosphere to avoid the idling loss of the low-pressure expansion section T4 under low load conditions; when the unit load is higher than the set load threshold, the controllable clutch device CP1 is connected, the second control valve V2 is closed, the third control valve V3 is opened, the low-pressure expansion section front heat exchanger HT4 is put into work, and the exhaust gas of the medium-pressure expansion section T3 is introduced into the low-pressure expansion section T4 to continue to work, restoring the normal working path.

[0043] Example 4: Double low-pressure expansion section configuration and super-high-pressure expansion section T0 disengagement

[0044] Based on the shaft configuration structure of the expander described in the foregoing embodiment 1, this embodiment is further applicable to large-scale compressed air energy storage systems with higher power levels, and proposes an extension structure that configures two low-pressure expansion sections T41 and T42 while maintaining the super-high-pressure expansion section T0 as the target disengagement section, aiming to improve the load adaptability and energy conversion efficiency of the system during sliding pressure operation.

[0045] As shown in Figure 3 In this embodiment 3, the power of the expander unit is further increased to two low-pressure expansion sections T41 and T42, and the target expansion section is still set as the super-high-pressure expansion section T0 connected to the high-pressure gas tank ST. The super-high-pressure expansion section T0 rotor is connected to the high-pressure expansion section T1 rotor through the gear box GB and the controllable clutch device CP1. The gear box GB can be flexibly selected according to whether the optimal design speed of the T0 section is consistent with the working range of the main shaft and the clutch speed. The connection and disengagement of the controllable clutch device CP1 is controlled by a pressure threshold. The generator G is adjusted to be located on the side of the low-pressure expansion section T42 rotor and is hard connected to the main expansion section T1-T42.

[0046] At least three control valves are provided in the connecting pipeline. The first control valve V1 is located before the super-high-pressure expansion section front heat exchanger T0, the second control valve V2 is located at the outlet of the super-high-pressure expansion section T0 exhaust section, and the third control valve V3 is located before the intersection of the high-pressure expansion section T1 inlet section and the super-high-pressure expansion section T0 outlet pipeline.

[0047] In the initial state of the system, the pressure of the gas tank ST is higher than the set pressure threshold P1, the T0 section has effective expansion conditions, the controllable clutch device CP1 is connected, the first and second control valves V1 and V2 are opened, the third control valve V3 is closed, all the pre-expansion heat exchangers are put into operation, and the full-section cascade operation is performed. The high-pressure gas passes through the ultra-high-pressure expansion section T0 and then sequentially passes through the high, medium-high, and medium-pressure expansion sections T1-T3, and then enters the first and second low-pressure expansion sections T41 and T42 in parallel to do work.

[0048] In the running process, the inlet pressure of the ultra-high-pressure expansion section T0 is monitored in real time. If it continuously drops below the set pressure threshold P1, the following disengagement control strategy is executed: the first and second control valves V1 and V2 are closed, and the controllable clutch device CP1 disengagement signal is triggered to stop the rotation of the ultra-high-pressure expansion section T0 rotor, avoid the loss of blowing, and close the pre-expansion heat exchanger HT0 of the ultra-high-pressure expansion section, while opening the third control valve V3 to make the medium-high-pressure gas in the gas tank bypass the target expansion section and enter the high-pressure expansion section T1 for continuous expansion and work, and the remaining sections are kept in cascade expansion operation to ensure uninterrupted power output.

[0049] Embodiment 5: Dual low-pressure expansion sections T41 and T42 can be disengaged

[0050] Based on the shaft configuration structure of the expander described in Embodiment 1, this embodiment further proposes a shaft configuration method in which both the dual low-pressure expansion sections T41 and T42 can be independently disengaged, aiming at the actual demand for multi-stage dynamic adjustment of the final-stage expansion section in a super-power-level compressed air energy storage system. This scheme can realize on-demand hierarchical access control of the low-pressure section, significantly enhancing the adaptability and energy utilization flexibility of the system during load changes.

[0051] As shown in FIG. 1, Figure 4 In this embodiment, the power of the expander set is further increased to require two low-pressure expansion sections T41 and T42, and the first low-pressure expansion section T41 and the second low-pressure expansion section T42 are set as the target expansion sections, and the first controllable clutch device CP1 and the second controllable clutch device CP2 are provided. The rotors of the first and second low-pressure expansion sections T41 and T42 are connected through the second controllable clutch device CP2, the rotor of the first low-pressure expansion section T41 and the rotor of the medium-pressure expansion section T3 are connected through the gear box GB and the controllable clutch device CP1, the gear box GB can be flexibly selected according to whether the optimal design speed of the low-pressure section T41 and T42 is consistent with the working range of the main shaft and the clutch speed, and the connection and disengagement of the clutch are controlled by the pressure threshold; the generator G is located on the side of the ultra-high-pressure expansion section T0 rotor and is hard-connected with the main expansion sections T0-T3.

[0052] At least four control valves are arranged in the connecting pipeline, the first control valve V1 is arranged in front of the pre-cooler T0 of the super-high pressure expansion section, the second control valve V2 is arranged on the exhaust pipeline of the middle pressure expansion section T3 and connected with the atmosphere, the third control valve V3 is arranged in front of the pre-cooler HT41 of the first low pressure expansion section, and the fourth control valve V4 is arranged in front of the pre-cooler HT42 of the second low pressure expansion section, and the two controllable clutch devices and the four control valves are cooperatively controlled to realize the staged input and output of the two low pressure expansion sections.

[0053] The unit load is monitored in real time, when the unit load is lower than the set load threshold P2, the low pressure expansion section T41 rotor is disconnected and stopped by the two controllable clutch controls CP1 and CP2, the second control valve V2 is opened, the third control valve V3 is closed to cut off the gas flow supply to the two low pressure expansion sections T41 and T42, the middle pressure expansion section T3 exhausts directly to the atmosphere, at this time, the pre-cooler HT0-HT3 works, and the pre-coolers HT41 and HT42 stop working.

[0054] With the load rising to be higher than the set load threshold P2 stably, the second control valve V2 is closed, the third control valve V3 is opened, the pre-cooler HT41 is put into work, the first low pressure expansion section T41 is connected through the first controllable clutch device CP1, and the gas flow enters the first low pressure expansion section T41 to work after passing through the middle pressure expansion section T3; with the load continuing to rise and being higher than the second set load threshold P2 stably, the fourth control valve V4 is opened, the pre-cooler HT42 is put into work, the second low pressure expansion section T42 is connected through the second controllable clutch device CP2, and the gas flow enters the two low pressure expansion sections T41 and T42 to work after passing through the middle pressure expansion section T3.

[0055] Through the above embodiment, the purpose of the present application is completely and effectively realized. Those skilled in the art can understand that the present application includes but is not limited to the content described in the above specific embodiments and the accompanying drawings. Although the present application has been described with respect to the presently preferred and most practical embodiments, it will be understood that the present application is not limited to the disclosed embodiments, and any modification not deviating from the functional and structural principles of the present application will be included in the scope of the claims.

Claims

1. A multi-stage expander shaft system configuration structure for a high-power compressed air energy storage system, comprising a high-pressure air storage tank, multiple turbine expansion sections, and a generator, characterized in that: The shaft system configuration structure is also provided with at least one controllable clutch device for dynamically connecting the target expansion section rotor and the main shaft system. The main shaft system is composed of a high-pressure gas storage tank connected in sequence to some or all of the rotors in the ultra-high pressure, high pressure, medium-high pressure, medium pressure and low pressure expansion sections and the generator in a rigid connection. Each turbine expansion section has a corresponding expansion section front heat exchanger on its air inlet pipeline. The controllable clutch device is located between the main shaft system and the target expansion section rotor. The target expansion section is one or more expansion sections that, under preset operating conditions, experience reduced operating efficiency and are prone to energy loss due to deviations in intake parameters or load requirements from the design point. By setting pressure and / or load operating parameter thresholds, and based on the real-time pressure and / or unit load parameters during system operation, the controllable clutch device is dynamically triggered to adjust the connection or disengagement between the target expansion section and the main shaft system. The shaft system configuration structure is also equipped with several control valves to cooperate with the controllable clutch device and control the intake and exhaust of the target expansion section; the high-pressure gas in the high-pressure storage tank sequentially passes through all or part of the ultra-high pressure, high pressure, medium pressure, and low pressure expansion sections to do work, and the high-pressure air passing through each expansion section is heated by the heat exchanger in front of the expansion section; and when the controllable clutch device is triggered to connect or disengage, the heat exchanger in front of the target expansion section opens or closes synchronously.

2. The multi-stage expander shaft system configuration structure of the high-power compressed air energy storage system according to claim 1, characterized in that, A gearbox is provided between the main shaft system and the target expansion section rotor. The gearbox is selected from single-stage reduction, double-stage compound reduction or variable ratio reduction transmission structure according to the matching relationship between the optimal design speed of the target expansion section and the working speed range of the main shaft system and the clutch. It is used to match the optimal design speed of the target expansion section with the actual speed range of the main shaft system when the controllable clutch device is connected, so as to ensure that the target expansion section can operate stably within its efficient working speed range.

3. The multi-stage expander shaft system configuration structure of the high-power compressed air energy storage system according to claim 1, characterized in that, The shaft system configuration also includes an operating status control unit that works in conjunction with the controllable clutch device and various control valves. This unit monitors the intake pressure of the target expansion section and / or the unit load operating parameters in real time. When the intake pressure of the target expansion section is consistently higher than the set pressure threshold or the unit load is consistently higher than the set load threshold, the controllable clutch device is in the connected state, maintaining the mechanical connection between the target expansion section rotor and the main shaft system, and each expansion section performs work normally. When the relevant operating status parameters continue to decrease and are consistently lower than the set threshold, a disengagement action is performed, causing the target expansion section rotor to mechanically separate from the main shaft system and stop rotating. At the same time, the control valves are adjusted to allow high-pressure gas to bypass the target expansion section and enter the subsequent expansion sections to continue performing work.

4. The multi-stage expander shaft system configuration structure of the high-power compressed air energy storage system according to claim 3, characterized in that, The controllable clutch device's motion control strategy includes graded threshold control and hysteresis control logic. By setting a connection threshold and a disengagement threshold, with the connection threshold being higher than the disengagement threshold to form a hysteresis characteristic, a disengagement action is triggered when the operating parameters are lower than the disengagement threshold, and a connection action is triggered when the operating parameters recover and stabilize above the connection threshold, thus avoiding frequent clutch switching near the threshold.

5. The multi-stage expander shaft system configuration structure of the high-power compressed air energy storage system according to claim 3 or 4, characterized in that, The shaft system configuration also includes a heat exchanger control unit that works in conjunction with the controllable clutch device. When the controllable clutch device triggers a disengagement action to separate the target expansion section rotor from the main shaft system, the heat exchanger before the expansion section corresponding to the target expansion section is simultaneously shut down to stop the heating treatment of the target expansion section. When the controllable clutch device triggers a connection action to re-establish the mechanical connection, the heat exchanger before the expansion section corresponding to the target expansion section is simultaneously turned on to resume the heating treatment of the high-pressure air entering the target expansion section, thereby achieving coordinated control of energy management and expansion section operating status.

6. The multi-stage expander shaft system configuration structure of the high-power compressed air energy storage system according to claim 1, characterized in that, The target expansion section is an ultra-high pressure expansion section connected to the high-pressure gas storage tank. A controllable clutch device is installed between the ultra-high pressure expansion section rotor and the high-pressure expansion section rotor. The generator is located on one side of the low-pressure expansion section rotor and is rigidly connected to the main expansion section rotor. The plurality of control valves include a first control valve, a second control valve, and a third control valve. The first control valve is installed before the heat exchanger in front of the ultra-high pressure expansion section, the second control valve is installed at the outlet of the ultra-high pressure expansion section exhaust section, and the third control valve is installed before the main gas flow pipeline intersects with the outlet pipeline of the ultra-high pressure expansion section. When the pressure in the high-pressure storage tank is higher than the first set pressure threshold in the initial state, the controllable clutch device is engaged, the first and second control valves are opened, the third control valve is closed, all heat exchangers before the expansion section are put into operation, and the entire expansion section is cascaded. When the intake pressure of the ultra-high pressure expansion section is continuously lower than the set pressure threshold, the first and second control valves are closed and the controllable clutch device is triggered to disengage. The rotor of the ultra-high pressure expansion section stops rotating and the heat exchanger in front of the expansion section is closed. At the same time, the third control valve is opened so that the high-pressure gas in the gas storage tank bypasses the target expansion section and enters the high-pressure expansion section through the bypass to continue to expand and do work.

7. The multi-stage expander shaft system configuration structure of the high-power compressed air energy storage system according to claim 1, characterized in that, The target expansion section is a low-pressure expansion section. A controllable clutch device is installed between the rotor of the low-pressure expansion section and the rotor of the medium-pressure expansion section. The generator is located on one side of the rotor of the ultra-high-pressure expansion section and is rigidly connected to the main expansion section. Several control valves include a first control valve, a second control valve, and a third control valve. The first control valve is installed before the heat exchanger of the ultra-high-pressure expansion section, the second control valve is installed on the exhaust pipe of the medium-pressure expansion section and connected to the atmosphere, and the third control valve is installed before the heat exchanger of the low-pressure expansion section. When the unit load is detected to be lower than the set load threshold, the controllable clutch disengages to stop the rotor of the low-pressure expansion section from rotating. The second control valve opens to allow the exhaust gas from the medium-pressure expansion section to be directly discharged into the atmosphere. The third control valve closes to cut off the airflow supply to the low-pressure expansion section and shuts down the heat exchanger in front of the expansion section to avoid idling losses in the low-pressure expansion section under low load conditions.

8. The multi-stage expander shaft system configuration structure of the high-power compressed air energy storage system according to claim 1, characterized in that, The plurality of turbine expansion sections include a first low-pressure expansion section and a second low-pressure expansion section arranged in parallel. The target expansion section is an ultra-high-pressure expansion section connected to a high-pressure gas storage tank. A controllable clutch device is disposed between the ultra-high-pressure expansion section rotor and the high-pressure expansion section rotor. The generator is adjusted to be located on one side of the low-pressure expansion section rotor and rigidly connected to the main expansion section rotor. A first control valve is disposed before the heat exchanger in front of the ultra-high-pressure expansion section. A second control valve is disposed at the outlet of the ultra-high-pressure expansion section exhaust section. A third control valve is disposed before the main gas flow pipeline intersects with the outlet pipeline of the ultra-high-pressure expansion section. When the pressure in the high-pressure gas storage tank is higher than the first set pressure threshold in the initial state, the controllable clutch device is connected, the first and second control valves are opened, the third control valve is closed, all heat exchangers before the expansion section are put into operation, and the high-pressure gas passes through the ultra-high pressure expansion section and then passes through the high pressure, medium-high pressure, and medium pressure expansion sections in sequence before entering the parallel first and second low-pressure expansion sections to do work. When the intake pressure of the ultra-high pressure expansion section is continuously lower than the set pressure threshold, the first and second control valves are closed and the controllable clutch device is triggered to disengage. The rotor of the ultra-high pressure expansion section stops rotating and the heat exchanger in front of the expansion section is closed. At the same time, the third control valve is opened so that the high-pressure gas in the gas storage tank bypasses the target expansion section and enters the high-pressure expansion section to continue to expand and do work.

9. The multi-stage expander shaft system configuration structure of the high-power compressed air energy storage system according to claim 1, characterized in that, The multiple turbine expansion sections include a first low-pressure expansion section and a second low-pressure expansion section arranged in parallel, with two low-pressure expansion sections designated as target expansion sections. A first controllable clutch device and a second controllable clutch device are provided. The first controllable clutch device is located between the rotors of the intermediate-pressure expansion section and the first low-pressure expansion section, and the second controllable clutch device is located between the rotors of the two low-pressure expansion sections. The generator is located on one side of the ultra-high-pressure expansion section rotor and is rigidly connected to the main expansion section. A first control valve is located before the heat exchanger of the ultra-high-pressure expansion section, a second control valve is located on the exhaust pipe of the intermediate-pressure expansion section and connected to the atmosphere, a third control valve is located before the heat exchanger of the first low-pressure expansion section, and a fourth control valve is located before the heat exchanger of the second low-pressure expansion section. The staged engagement and disengagement of the two low-pressure expansion sections are achieved through the coordinated control of the two controllable clutch devices and the four control valves. When the unit load is detected to be lower than the set load threshold, both controllable clutches disengage to stop the rotors of the two low-pressure expansion sections from rotating. The second control valve opens to allow the exhaust gas from the medium-pressure expansion section to be discharged into the atmosphere. The third control valve closes to cut off the airflow supply to the two low-pressure expansion sections and shuts down the heat exchangers in front of the expansion sections to avoid idling losses in the two low-pressure expansion sections under low load conditions. When the unit load rises to a stable level above the set load threshold, the second control valve closes, the third control valve opens, and the first controllable clutch device triggers a connection action to restore the first low-pressure expansion section to work, and at the same time restores the operation of the heat exchanger before its expansion section. When the unit load continues to rise and stabilizes at a higher second set load threshold, the fourth control valve is opened, the second controllable clutch device is connected to restore the operation of the second low-pressure expansion section, and the heat exchanger before the expansion section is restored to operation. After passing through the medium-pressure expansion section, the airflow enters the two low-pressure expansion sections to do work.

10. A high-power compressed air energy storage system, characterized in that, The expander shaft system configuration structure includes any one of claims 1 to 9.

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