Carbon dioxide gas-liquid-solid three-phase composite energy storage system and collaborative control method

Abstract

The present application belongs to the field of compressed gas energy storage and thermal system, and particularly relates to a carbon dioxide gas-liquid-solid three-phase composite energy storage system and a collaborative control method. The system comprises compressed condensation, liquid storage, solid preparation and storage, energy release and power generation, and a collaborative control unit. The core of the method is that in the energy release stage, the stored solid carbon dioxide and liquid carbon dioxide are introduced into a multi-phase exchanger in a controlled proportion for heat and mass exchange, and the proportion is dynamically adjusted by the collaborative control unit to control the output power of the system. This effectively overcomes the problem of output power attenuation caused by the decrease of storage tank pressure in the energy release stage of traditional liquid carbon dioxide energy storage system, and improves the energy storage density and operation flexibility of the system.

Description

Technical Field

[0001] This invention belongs to the field of compressed gas energy storage and thermal systems, specifically relating to a carbon dioxide gas-liquid-solid three-phase composite energy storage system and a synergistic control method. Background Technology

[0002] As the global energy structure accelerates its transition to renewable energy, the large-scale grid connection of intermittent wind and solar power generation places higher demands on the flexible regulation capabilities of the power system. Compressed gas energy storage, as a large-scale, long-term energy storage technology, has attracted widespread attention due to its advantages such as flexible site selection and long lifespan. Among them, energy storage technology using carbon dioxide as the working medium shows good application potential due to its high critical temperature, easy liquefaction, and high density. Currently, carbon dioxide-based energy storage technologies mainly focus on its gaseous, liquid, and supercritical states.

[0003] Early carbon dioxide energy storage technologies primarily employed gaseous storage. During the storage phase, electricity was used to compress carbon dioxide gas to high pressure and store it in a storage device. During the release phase, the high-pressure gas absorbed heat through a regenerator and expanded to drive a generator. This technology is relatively simple in structure, but its energy density is limited by the gas storage pressure, typically requiring large storage containers or underground caverns, making it somewhat dependent on geographical conditions. Furthermore, the overall system efficiency and scale improvement face bottlenecks. To improve energy storage density, liquid carbon dioxide energy storage technology emerged. This technology significantly reduces tank volume by cooling and liquefying carbon dioxide for storage at atmospheric or low pressure. During release, the liquid carbon dioxide is pressurized by a pump and heated by a regenerator, transforming into a supercritical state or high-temperature, high-pressure gas to drive an expander. However, in actual operation, the pressure inside the liquid storage tank continuously decreases as the working fluid is released, directly leading to a reduction in the pressure and flow rate at the expander inlet, and consequently, a decrease in the unit's output power. This inherent power decay characteristic makes it difficult for the system to maintain stable power output over a long release phase, impacting the power support and regulation quality of the power grid. To address the power decay issue, some studies have shifted towards maintaining stable working fluid pressure during the energy release phase, such as using multi-stage tanks in series or complex pressure compensation loops. However, these methods often increase system complexity and investment costs. On the other hand, supercritical carbon dioxide energy storage systems operate efficiently near the critical point, but they are extremely sensitive to operating parameters, making control complex, and they also need to address the challenges of operating condition drift caused by changes in tank pressure.

[0004] Meanwhile, the properties of carbon dioxide near its triple point have also attracted researchers' attention. Solid carbon dioxide (dry ice), as a high-density energy storage medium, has a storage pressure close to atmospheric pressure and a volumetric energy storage density far higher than that of gaseous or even liquid states. Existing technologies have already explored the use of carbon dioxide's phase change properties for energy storage. For example, liquid carbon dioxide can be converted into dry ice to store cold energy during energy storage, or the sublimation of dry ice can be used to absorb heat and assist in cooling the working fluid during energy release. However, most of these applications treat solid carbon dioxide as a passive cold source or a fixed phase change material library. Its utilization is usually decoupled from the main cycle or used for static energy transfer, failing to deeply integrate it into the dynamic power generation process of the main working fluid flow. This fails to fundamentally solve the problem of power output stability in the main energy storage loop during continuous energy release.

[0005] In summary, existing carbon dioxide energy storage technologies, whether based on gaseous, liquid, or supercritical states, often struggle to simultaneously address the energy release process, particularly the stability of output power during long-term energy release, while pursuing high energy density. For the utilization of solid carbon dioxide, current solutions primarily focus on its static cold energy storage or auxiliary cooling functions, failing to fully leverage its potential as a flexibly dispatchable and actively controllable "regulatory resource" for power output. Therefore, constructing a novel energy storage system that can effectively overcome the challenge of energy release power decay while maintaining high energy density, and achieving flexible and stable control of output power, has become a technical direction worthy of in-depth exploration in this field. Summary of the Invention

[0006] This application aims to overcome the shortcomings of existing liquid carbon dioxide energy storage systems, such as power attenuation and instability due to tank pressure drop during the energy release phase. Therefore, it provides a carbon dioxide gas-liquid-solid three-phase composite energy storage system and its collaborative control method that innovatively integrates gaseous, liquid and solid phases for synergistic energy storage using carbon dioxide as the working medium.

[0007] To achieve the above-mentioned objectives, the present invention is implemented through the following technical solution: In a first aspect, the present invention provides a carbon dioxide gas-liquid-solid three-phase composite energy storage system, characterized in that it comprises: The compression-condensation module is used to compress and condense gaseous carbon dioxide into liquid or supercritical carbon dioxide. A liquid storage module, connected to the compression and condensation module, is used to store the liquid or supercritical carbon dioxide; A solid-state preparation and storage module, connected to the compression and condensation module and / or the liquid storage module, is used to convert at least a portion of the liquid or supercritical carbon dioxide into solid carbon dioxide and store it. An energy release power generation module is connected to the liquid storage module and the solid preparation and storage module. The energy release power generation module includes a multiphase exchanger for exchanging heat and mass with the solid carbon dioxide from the solid preparation and storage module and the liquid carbon dioxide from the liquid storage module, and generating electricity using the working fluid after the heat and mass exchange. The collaborative control unit is communicatively connected to the solid-state preparation and storage module and the energy release and power generation module, and is used to collaboratively control the solid-state preparation and storage module and the energy release and power generation module to adjust the output power of the system.

[0008] In the field of carbon dioxide energy storage technology, existing systems based on liquid or supercritical working fluids generally face the problem of deteriorating expander inlet conditions and consequently decreasing output power during long-term energy release due to the irreversible drop in tank pressure. To address this issue, the system protected in this application offers a novel technical approach. Its innovation does not stem from simple optimization of individual components such as compressors, expanders, or heat exchangers, but rather from a re-understanding and systematic reconstruction of the value of the working fluid's phase state. Its core lies in transforming solid carbon dioxide from a static, secondary energy storage form into a dynamic, precisely deliverable "power regulation medium," and leveraging this function through a deeply synergistic architecture and methodology.

[0009] Compared to the traditional linear "compression-storage-expansion" process, this scheme constructs a composite platform that allows energy to be stored, converted, and released on demand between the gas, liquid, and solid phases. The introduction of the "solid-state preparation and storage module" is a key step, enabling the system to not only store energy in high-pressure liquids but also strategically convert a portion of liquid carbon dioxide into near-atmospheric-pressure dry ice, significantly increasing the volumetric energy density for long-term energy storage. However, the more innovative design lies in the integration of the "multiphase exchanger" within the "energy release and power generation module" and the global scheduling of the "cooperative control unit." The multiphase exchanger is the physical core for the active and controllable interaction between liquid and solid flows. It is not a traditional heater or cooler but an interface device specifically designed to facilitate efficient heat and mass exchange between the liquid and solid working fluids. It is through this interface that the dry ice stored in the solid-state preparation and storage module is activated from a "silent" energy storage state into an "active" power regulation mechanism.

[0010] In the basic energy release mode, the system is similar to traditional liquid energy storage, primarily utilizing the high-pressure working fluid in the liquid storage tank to perform work. When power needs to be increased or a pressure drop in the storage tank needs to be addressed, the co-control unit activates the enhanced energy release mode. The essence of this mode lies in the real-time, dynamic control of the "ratio." Based on real-time grid power demand commands and pressure feedback from the liquid storage tank, it uses a built-in algorithm model to precisely calculate the optimal ratio of liquid carbon dioxide flow rate to solid carbon dioxide injection rate required to maintain or achieve the target power output. Subsequently, it synchronously directs the high-pressure pump and the dry ice storage chamber's discharge mechanism to deliver a specific flow rate of high-pressure liquid carbon dioxide and calculated-rate dry ice particles together into the multiphase exchanger. Inside the exchanger, the dry ice and liquid carbon dioxide come into direct contact. The dry ice sublimates, absorbing a large amount of latent heat, producing a strong cooling effect on the surrounding liquid working fluid. This process produces key thermodynamic effects: the deeply cooled liquid carbon dioxide experiences a decrease in temperature, an increase in density, and a decrease in enthalpy per unit mass of working fluid. When this low-temperature, high-pressure, and high-density fluid enters the subsequent expander, it can perform more work under the same pressure drop. More importantly, even when the pressure in the liquid storage tank has decreased, active cooling of the working fluid can effectively improve the inlet operating conditions of the expander, thus maintaining rated power output at a lower inlet pressure. Throughout the process, the consumption rate of solid carbon dioxide is not a fixed value, but a variable closely coupled with the flow rate of the liquid working fluid, the storage tank pressure, and the target power. The control system, through closed-loop regulation, makes the introduction of dry ice act like a "power compensation valve," smoothly offsetting the power attenuation trend caused by the emptying of the storage tank.

[0011] Therefore, the beneficial effects of this technical solution are systemic. First, it effectively improves the problem of unstable output power in liquid carbon dioxide energy storage systems during the energy release cycle, enabling the system to respond to the grid's demand for stable power or flexible power adjustment. Second, by introducing solid-state storage, the system gains greater potential for long-term, large-scale energy storage while maintaining its high energy density advantage. Finally, through intelligent management of the gas, liquid, and solid three-phase working fluid storage and release strategies by the collaborative control unit, the system's operational flexibility and dispatchability are improved.

[0012] Preferably, the solid-state preparation and storage module includes: A dry ice preparation unit is used to receive the liquid or supercritical carbon dioxide and convert it into solid carbon dioxide. A dry ice storage chamber, connected to the dry ice preparation unit, is used to store the solid carbon dioxide.

[0013] Preferably, the dry ice preparation unit includes a rapid expansion valve and a compaction molding device. The rapid expansion valve is used to throttle and expand liquid or supercritical carbon dioxide to solidify it, and the compaction molding device is used to press the solidified carbon dioxide into shape.

[0014] Preferably, the multiphase exchanger is a liquid-solid direct contact heat exchanger, including a spray tower structure or a fluidized bed structure.

[0015] Preferably, the energy release power generation module further includes: A high-pressure pump, the inlet of which is connected to the liquid storage module, and the outlet of which is connected to the liquid working fluid inlet of the multiphase exchanger; An expander, the inlet of which is connected to the outlet of the multiphase exchanger, is used to convert the energy of the working fluid after heat and mass exchange into mechanical energy. A generator, connected to the expander, is used to convert mechanical energy into electrical energy.

[0016] Preferably, the coordinated control unit is configured to adjust the rate at which the solid carbon dioxide is delivered to the multiphase exchanger based on the power command of the power grid and / or the pressure of the liquid storage module.

[0017] Preferably, the collaborative control unit is configured to execute an enhanced energy release mode: when a pressure drop in the liquid storage module is detected and / or the power command of the power grid is higher than a threshold, the rate at which the solid carbon dioxide is delivered to the multiphase exchanger is increased.

[0018] Preferably, the system also includes a low-pressure gas storage tank connected to the inlet of the compression condensation module and the outlet of the energy release power generation module for storing gaseous carbon dioxide.

[0019] Secondly, the present invention also provides a synergistic control method for the aforementioned carbon dioxide gas-liquid-solid three-phase composite energy storage system, comprising: Energy storage stage: compressing and condensing gaseous carbon dioxide into liquid or supercritical carbon dioxide and storing it in a liquid storage module; and converting at least a portion of the liquid or supercritical carbon dioxide into solid carbon dioxide and storing it. Energy release stage: The liquid carbon dioxide stored in the liquid storage module and the solid carbon dioxide stored are introduced into the multiphase exchanger in a controlled ratio for heat and mass exchange, and the working fluid after heat and mass exchange is used to generate electricity. The output power of the system is adjusted by regulating the control ratio of the solid carbon dioxide to the liquid carbon dioxide.

[0020] Preferably, during the energy release phase, the heat and mass exchange is a direct contact heat exchange between liquid carbon dioxide and solid carbon dioxide.

[0021] Preferably, the control ratio is dynamically adjusted based on the real-time power command of the power grid and / or the storage pressure of liquid carbon dioxide in the liquid storage module.

[0022] Preferably, during the energy release phase, when a decrease in the storage pressure of the liquid carbon dioxide and / or an increase in the real-time power command of the power grid are detected, the proportion of solid carbon dioxide introduced is increased.

[0023] As a preferred option, during non-grid peak shaving periods, the process of converting liquid or supercritical carbon dioxide into solid carbon dioxide can be operated independently to produce commercial dry ice.

[0024] Therefore, this application has the following beneficial effects: (1) By introducing solid carbon dioxide as an active power regulation unit and conducting controllable heat and mass exchange between it and liquid carbon dioxide in a multiphase exchanger during the energy release phase, the problem of output power attenuation caused by the drop in tank pressure in traditional liquid carbon dioxide energy storage system is effectively improved, which helps to achieve more stable power output. (2) Solid carbon dioxide has a storage pressure close to atmospheric pressure but a high volumetric energy density. Its introduction significantly increases the overall energy storage density of the system and enhances its ability to store energy over a long period of time and on a large scale. (3) By intelligently coordinating the storage and release of gas, liquid and solid working fluids through the collaborative control unit, the system can quickly and wide-range adjust the power generation, thereby significantly improving the operational flexibility in response to grid peak shaving, frequency regulation and other commands; (4) The solid-state preparation module can independently produce commercial dry ice during off-peak hours of the power grid, opening up a non-electricity value-added revenue channel for the system; (5) The heat exchange method of direct liquid-solid contact reduces the heat transfer temperature difference and irreversible loss, which has a positive impact on improving the overall circulation efficiency of the system. Attached Figure Description

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

[0026] Figure 2 This is a schematic diagram of a multiphase switch according to the present invention.

[0027] Figure 3 This is a logic flowchart of the present invention.

[0028] The components include: compressor 1, cooler 2, high-pressure liquid tank 3, dry ice preparation unit 4, dry ice storage chamber 5, high-pressure pump 6, multiphase exchanger 7, expander 8, generator 9, co-control unit 10, and spray head 71. Detailed Implementation

[0029] The present invention will be further described below with reference to specific embodiments. Those skilled in the art will be able to implement the present invention based on these descriptions. Furthermore, the embodiments of the present invention described below are generally only some, not all, of the embodiments of the present invention. Therefore, all other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0030] Combination Figure 1 The embodiments of the present invention are as follows: The present invention provides a carbon dioxide gas-liquid-solid three-phase composite energy storage system, one specific embodiment of which includes a compression condensation module, a liquid storage module, a solid preparation and storage module, an energy release and power generation module, and a collaborative control unit 10.

[0031] The compression-condensation module is used to compress and condense gaseous carbon dioxide into liquid or supercritical carbon dioxide. See also Figure 1 This module mainly consists of a compressor 1 and a cooler 2 connected in sequence. The inlet of compressor 1 is connected to a low-pressure gas storage tank or a system return gas pipeline to draw in low-pressure carbon dioxide gas. Cooler 2 cools the high-temperature, high-pressure carbon dioxide gas discharged from compressor 1, causing it to condense into a liquid or supercritical working fluid.

[0032] The liquid storage module is connected to the compression and condensation module and is used to store the condensed working fluid. Figure 1 As shown, the module includes at least one high-pressure storage tank, such as a high-pressure liquid tank 3. The inlet of the high-pressure liquid tank 3 is connected to the outlet of the cooler 2 via a pipe and valve V1, for receiving and storing liquid or supercritical carbon dioxide.

[0033] The solid-state preparation and storage module is connected to the compression and condensation module and / or the liquid-state storage module, and is used to convert at least a portion of liquid or supercritical carbon dioxide into solid carbon dioxide and store it. See also Figure 1 This module specifically includes a dry ice preparation unit 4 and a dry ice storage chamber 5. The inlet of the dry ice preparation unit 4 can be selectively connected via a pipe and valve V2 to the outlet of a liquid storage module, such as a high-pressure liquid tank 3, or the outlet of a cooler 2 in a compression condensation module. This unit includes a rapid expansion valve and a compaction molding device (not shown separately in the figure). When liquid carbon dioxide flows through the rapid expansion valve, it undergoes throttling and expansion, partially vaporizing and absorbing a large amount of heat, causing the remaining portion to rapidly solidify into carbon dioxide snow. Subsequently, the carbon dioxide snow is fed into the compaction molding device, where it is compressed into high-density dry ice blocks or granules under high pressure. The dry ice storage chamber 5 is an insulated container connected to the outlet of the dry ice preparation unit 4, used to store the prepared solid carbon dioxide dry ice in a low-temperature, low-pressure environment. Its bottom is equipped with a controllable discharge mechanism, such as a screw feeder.

[0034] The energy release and power generation module is connected to the liquid storage module and the solid-state preparation and storage module for power generation. For example... Figure 1 As shown, this module mainly includes a high-pressure pump 6, a multiphase exchanger 7, an expander 8, and a generator 9. The inlet of the high-pressure pump 6 is connected to the outlet of the high-pressure liquid tank 3 via pipes and valves, used to pressurize the liquid carbon dioxide. The multiphase exchanger 7 is one of the core devices in this embodiment, and it has at least two independent channels: a liquid carbon dioxide flow channel, the inlet of which is connected to the outlet of the high-pressure pump 6; and a dry ice contact chamber, connected to the discharge mechanism of the dry ice storage chamber 5. The multiphase exchanger 7 is used to enable direct contact heat and mass exchange between solid carbon dioxide from the solid preparation and storage module and liquid carbon dioxide from the liquid storage module within its interior. In a preferred embodiment, as shown... Figure 2 As shown, the multiphase exchanger 7 can adopt a spray tower structure, with spray heads 71 ​​at the top for uniformly spraying high-pressure liquid carbon dioxide downwards; dry ice particles are fed in from the side and fall inside the tower, fully contacting, exchanging heat with, and sublimating the falling droplets. The inlet of the expander 8 is connected to the gas-liquid mixing outlet of the multiphase exchanger 7, and its shaft is connected to the generator 9, using the expansion of the working fluid to drive the generator 9 to generate electricity. The outlet of the expander 8 is connected to the low-pressure gas storage tank or the inlet of the compressor 1 to complete the cycle.

[0035] The collaborative control unit 10 serves as the intelligent control center of the system. Its electrical connections with the power grid dispatching system, as well as various sensors, valves V1, V2…, compressor 1, high-pressure pump 6, the discharge mechanism of the dry ice storage chamber 5, expander 8, and other actuators within the system are shown as dashed lines in the diagram. It receives power commands from the power grid and system status signals such as the pressure of the high-pressure liquid tank 3 and the outlet temperature of the multiphase exchanger 7, and outputs control commands to collaboratively control the solid-state preparation and storage module and the energy release and power generation module, thereby dynamically adjusting the system's output power.

[0036] The system's operating method, namely a cooperative control method, includes the following modes: Energy storage phase: During periods of low grid load, the coordinating control unit 10 starts the compressor 1 to compress carbon dioxide gas, which is then condensed by the cooler 2 and mostly stored in the high-pressure liquid tank 3. Simultaneously, based on energy storage requirements, the control unit can decide to open valve V2 to introduce a portion of the liquid carbon dioxide into the dry ice preparation unit 4, producing dry ice and storing it in the dry ice storage chamber 5.

[0037] Basic power release mode: When the grid needs basic power, the coordinating control unit 10 controls the start of the high-pressure pump 6 to extract liquid carbon dioxide from the high-pressure liquid tank 3. After being pressurized, it flows into the multiphase exchanger 7. At this time, dry ice may not be put in or only a small amount may be put in. It mainly relies on external heat sources such as regenerators (not shown in the figure) to heat the water and then enter the expander 8 to generate electricity.

[0038] Enhanced / Stabilized Energy Release Mode: When the power demand of the power grid increases, or when the sensor detects a drop in pressure inside the high-pressure liquid tank 3, resulting in insufficient inlet pressure at the expander 8, the co-control unit 10 activates this core mode. For example... Figure 3 As shown in the logic flowchart, the control unit synchronously performs the following operations: a) controlling the high-pressure pump 6 to maintain or regulate the flow rate of liquid carbon dioxide; b) controlling the discharge mechanism of the dry ice storage tank 5 to deliver dry ice to the dry ice contact chamber of the multiphase exchanger 7 at a calculated rate. Inside the multiphase exchanger 7, the dry ice comes into direct contact with the high-pressure liquid carbon dioxide, and the dry ice sublimates, absorbing a large amount of latent heat, resulting in a dramatic cooling effect on the liquid carbon dioxide. The deeply cooled liquid carbon dioxide has a lower temperature and increased density, and then enters the expander 8. This process compensates for the negative impact caused by the drop in tank pressure, enabling the maintenance of rated power at lower inlet pressures, and even increasing the single-cycle work capacity. The cooperating control unit 10, based on parameters such as real-time grid power commands, high-pressure tank 3 pressure, and multiphase exchanger 7 outlet temperature, dynamically and precisely adjusts the dry ice input rate through a closed-loop control algorithm, thereby achieving smooth, rapid, and wide-range adjustment of the system output power.

[0039] In addition, during off-peak periods, the system can operate the dry ice preparation unit 4 independently to produce commercial dry ice using off-peak electricity, thereby generating added value.

[0040] The above embodiments have detailed the principles and implementation methods of the present invention. For those skilled in the art, any improvements and modifications made to certain implementation details without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A carbon dioxide gas-liquid-solid three-phase composite energy storage system, characterized in that, include: The compression and condensation module is used to compress and condense gaseous carbon dioxide into liquid or supercritical carbon dioxide. A liquid storage module, connected to the compression and condensation module, is used to store the liquid or supercritical carbon dioxide; A solid-state preparation and storage module, connected to the compression and condensation module and / or the liquid storage module, is used to convert at least a portion of the liquid or supercritical carbon dioxide into solid carbon dioxide and store it. An energy release power generation module is connected to the liquid storage module and the solid preparation and storage module. The energy release power generation module includes a multiphase exchanger for exchanging heat and mass with the solid carbon dioxide from the solid preparation and storage module and the liquid carbon dioxide from the liquid storage module, and generating electricity using the working fluid after the heat and mass exchange. The collaborative control unit is communicatively connected to the solid-state preparation and storage module and the energy release and power generation module, and is used to collaboratively control the solid-state preparation and storage module and the energy release and power generation module to adjust the output power of the system.

2. The system according to claim 1, characterized in that, The solid-state preparation and storage module includes: A dry ice preparation unit is used to receive the liquid or supercritical carbon dioxide and convert it into solid carbon dioxide. A dry ice storage chamber, connected to the dry ice preparation unit, is used to store the solid carbon dioxide.

3. The system according to claim 2, characterized in that, The dry ice preparation unit includes a rapid expansion valve and a compaction molding device. The rapid expansion valve is used to throttle and expand liquid or supercritical carbon dioxide to solidify it, and the compaction molding device is used to press the solidified carbon dioxide into shape.

4. The system according to claim 1, characterized in that, The multiphase exchanger is a liquid-solid direct contact heat exchanger, including a spray tower structure or a fluidized bed structure.

5. The system according to claim 1, characterized in that, The energy release power generation module also includes: A high-pressure pump, the inlet of which is connected to the liquid storage module, and the outlet of which is connected to the liquid working fluid inlet of the multiphase exchanger; An expander, the inlet of which is connected to the outlet of the multiphase exchanger, is used to convert the energy of the working fluid after heat and mass exchange into mechanical energy; A generator, connected to the expander, is used to convert mechanical energy into electrical energy.

6. The system according to claim 1, characterized in that, The coordinated control unit is configured to adjust the rate at which the solid carbon dioxide is delivered to the multiphase exchanger based on the power command from the power grid and / or the pressure of the liquid storage module.

7. The system according to claim 6, characterized in that, The co-control unit is configured to execute an enhanced energy release mode: when a pressure drop in the liquid storage module is detected and / or the power command of the power grid is higher than a threshold, the rate at which the solid carbon dioxide is delivered to the multiphase exchanger is increased.

8. The system according to claim 1, characterized in that, It also includes a low-pressure gas storage tank connected to the inlet of the compression condensation module and the outlet of the energy release power generation module for storing gaseous carbon dioxide.

9. A collaborative control method for a carbon dioxide gas-liquid-solid three-phase composite energy storage system as described in any one of claims 1-8, characterized in that, include: Energy storage stage: Gaseous carbon dioxide is compressed and condensed into liquid or supercritical carbon dioxide and stored in a liquid storage module; In addition, at least a portion of the liquid or supercritical carbon dioxide is converted into solid carbon dioxide and stored; Energy release stage: The liquid carbon dioxide stored in the liquid storage module and the solid carbon dioxide stored are introduced into the multiphase exchanger in a controlled ratio for heat and mass exchange, and the working fluid after heat and mass exchange is used to generate electricity. The output power of the system is adjusted by regulating the control ratio of the solid carbon dioxide to the liquid carbon dioxide.

10. The method according to claim 9, characterized in that, During the energy release phase, the heat and mass exchange is a direct contact heat exchange between liquid carbon dioxide and solid carbon dioxide. The control ratio is dynamically adjusted based on the real-time power command from the power grid and / or the storage pressure of the liquid carbon dioxide in the liquid storage module; and, During the energy release phase, when a decrease in the storage pressure of the liquid carbon dioxide and / or an increase in the real-time power command of the power grid are detected, the proportion of solid carbon dioxide introduced is increased.

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