Working medium energy compensation device, carbon dioxide energy storage system and control method of carbon dioxide energy storage system

Abstract

The invention discloses a working medium energy compensation device, a carbon dioxide energy storage system and a control method thereof. The working medium energy compensation device comprises an air compression mechanism and a state parameter acquisition unit, the input end of the air compression mechanism is connected to an air storage unit, the output end of the air compression mechanism is connected to an input pipeline of a turbine, and the state parameter acquisition unit is connected to the input pipeline; the state parameter acquisition unit is configured to detect and obtain state parameters of carbon dioxide gas in an input pipeline and calculate and determine an input working medium energy value input to an inlet of a turbine; and the air compression mechanism is configured to compress the carbon dioxide gas in the gas storage unit and then input the compressed carbon dioxide gas into the input pipeline to supplement the working medium energy when the input working medium energy value does not reach the preset working medium energy value, so that the input working medium energy value reaches the preset working medium energy value. According to the scheme, it can be ensured that the running efficiency of the turbine can reach the efficiency design value, and the overall running efficiency and stability of the carbon dioxide energy storage system are improved.

Description

Technical Field

[0001] This invention relates to the field of carbon dioxide energy storage technology, and in particular to a working fluid energy compensation device, a carbon dioxide energy storage system and its control method. Background Technology

[0002] Utilizing clean energy sources such as solar and wind power to mitigate the consumption of non-renewable traditional energy sources like coal and oil has become an inevitable choice. Due to the intermittent, fluctuating, and off-peak generation characteristics of clean energy, energy storage technology has become one of the key technologies for clean energy development. Currently, energy storage technology based on carbon dioxide gas-liquid phase change cycle compresses and condenses gaseous carbon dioxide at room temperature and pressure into liquid carbon dioxide during off-peak electricity periods using surplus electricity or clean energy sources. The heat generated during compression is stored, and during peak electricity periods, this stored heat is used to heat the liquid carbon dioxide back to a gaseous state. The gaseous carbon dioxide then drives a turbine to generate electricity, and the gaseous carbon dioxide, after performing work, returns to the storage tank for reuse. This technology, with its advantages of simple structure, flexible layout, and high energy storage efficiency, has gradually attracted widespread attention.

[0003] In the energy release components of a carbon dioxide energy storage system, the gas delivery pipeline connecting the outlet of the energy release heat exchanger to the inlet of the turbine is relatively long. When the carbon dioxide gas heated by the energy release heat exchanger is delivered to the inlet of the turbine, its temperature and pressure are reduced to varying degrees, resulting in energy loss of the working medium. Often, the energy of the working medium input to the turbine inlet cannot reach the system set value, causing the turbine's operating efficiency to fail to reach the design value and affecting the stability of the system operation. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a working fluid energy compensation device, a carbon dioxide energy storage system, and a control method thereof, in order to solve the problem of how to compensate for the working fluid energy of carbon dioxide gas input to the turbine inlet, thereby improving the operational stability of the carbon dioxide energy storage system.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: The first aspect of this invention provides a working fluid energy compensation device for a carbon dioxide energy storage system. The carbon dioxide energy storage system includes a gas storage unit, an energy storage component, a liquid storage unit, and an energy release component connected in a closed loop. The working fluid energy compensation device includes a compressor and a state parameter acquisition unit. The energy release component includes a turbine. The input end of the compressor is connected to the gas storage unit, and the output end of the compressor is connected to the input pipeline of the turbine. The state parameter acquisition unit is connected to the input pipeline. The state parameter acquisition unit is configured to: detect and acquire the state parameters of carbon dioxide gas in the input pipeline, and calculate and determine the energy value of the input working fluid input to the inlet of the turbine based on the state parameters; The gas compression mechanism is configured such that when the input working fluid energy value fails to reach the preset working fluid energy value, the carbon dioxide gas in the gas storage unit is compressed and input into the input pipeline to supplement the working fluid energy, so that the input working fluid energy value reaches the preset working fluid energy value. The preset working fluid energy value is the input working fluid energy value set by the system to enable the turbine to achieve the efficiency design value.

[0006] In one specific embodiment, the energy release assembly includes a first-stage turbine to an Nth-stage turbine connected in sequence, the output end of the compressor is interconnected with the input pipelines of each stage of the turbine, and the state parameter acquisition unit is interconnected with the input pipelines of each stage of the turbine. The state parameter acquisition unit is configured to: detect and acquire the state parameters of carbon dioxide gas in the input pipelines of each stage of the turbine, and calculate and determine the energy value of the input working fluid input to the inlet of each stage of the turbine based on the state parameters. The gas compression mechanism is configured such that when the energy value of the input working fluid input to the inlet of the nth stage turbine fails to reach the preset energy value of the working fluid of the nth stage turbine, the carbon dioxide gas in the gas storage unit is compressed and input to the input pipeline corresponding to the nth stage turbine to supplement the working fluid energy, so that the energy value of the input working fluid input to the inlet of the nth stage turbine reaches the preset energy value of the working fluid of the nth stage turbine; Where N is an integer greater than or equal to 2, and n = 1, 2, ..., N.

[0007] In one specific embodiment, the output end of the compressor is connected to an output main pipeline, the output main pipeline is connected to N output branches, and the output main pipeline is connected to the input pipeline corresponding to the nth stage turbine through the nth output branch.

[0008] In one specific scheme, each of the output branches is equipped with a control valve and a check valve.

[0009] In one specific embodiment, the working fluid energy compensation device further includes a control unit. The gas compression mechanism and the state parameter acquisition unit are electrically connected to the control unit. The state parameter acquisition unit feeds back the detected state parameters to the control unit. The control unit calculates and determines the input working fluid energy value at the turbine inlet based on the state parameters and judges whether the preset working fluid energy value has been reached. When the input working fluid energy value fails to reach the preset working fluid energy value, the control unit controls the gas compression mechanism to compress the carbon dioxide gas in the gas storage unit and input it into the input pipeline to supplement the working fluid energy.

[0010] In one specific embodiment, the state parameters include the pressure, temperature, and flow rate of carbon dioxide gas. The compressor controls the energy of the working medium supplied to the input pipeline by adjusting the pressure and / or temperature and / or flow rate of the output compressed carbon dioxide gas.

[0011] In one specific embodiment, the driving power for the air compressor comes from a photovoltaic power generation system or a wind power generation system.

[0012] A second aspect of the present invention is to provide a carbon dioxide energy storage system, comprising a gas storage unit, an energy storage component, a liquid storage unit, and an energy release component connected in a closed loop in sequence, wherein the carbon dioxide energy storage system further comprises the working fluid energy compensation device as described above.

[0013] A third aspect of the present invention is to provide a control method for a carbon dioxide energy storage system as described above, comprising: The state parameter acquisition unit monitors and acquires the state parameters of carbon dioxide gas in the input pipeline in real time, and calculates and determines the energy value of the input working fluid input to the inlet of the turbine based on the state parameters. When the input working fluid energy value fails to reach the preset working fluid energy value, the compressor is controlled to compress the carbon dioxide gas in the gas storage unit and input it into the input pipeline to supplement the working fluid energy, so that the input working fluid energy value reaches the preset working fluid energy value.

[0014] In one specific embodiment, the working fluid energy compensation device further includes a control unit, and the control method includes: The status parameter acquisition unit monitors and acquires the status parameters of the carbon dioxide gas in the input pipeline in real time and feeds them back to the control unit. The control unit calculates and determines the input working fluid energy value at the inlet of the turbine based on the state parameters and determines whether the preset working fluid energy value has been reached. When the input working fluid energy value fails to reach the preset working fluid energy value, the control unit calculates and determines the working fluid energy that needs to be supplemented and sends a control command to the compressor mechanism; The gas compression mechanism compresses the carbon dioxide gas in the gas storage unit and inputs it into the input pipeline according to the control command to supplement the working medium energy, so that the input working medium energy value reaches the preset working medium energy value.

[0015] The working fluid energy compensation device, carbon dioxide energy storage system, and control method provided in this invention, during the operation of the energy storage system, acquire the state parameters of carbon dioxide gas in the input pipeline in real time through a state parameter acquisition unit, and calculate and determine the input working fluid energy value at the turbine inlet. When the input working fluid energy value fails to reach the preset working fluid energy value, the carbon dioxide gas in the gas storage unit is compressed by a gas compression mechanism and then input into the input pipeline to replenish the working fluid energy in a timely manner, so that the input working fluid energy value can reach the preset working fluid energy value, ensuring that the turbine's operating efficiency can reach the efficiency design value, and improving the overall efficiency and stability of the carbon dioxide energy storage system. Attached Figure Description

[0016] Figure 1 This is a detailed connection structure diagram of the working fluid energy compensation device and the carbon dioxide energy storage system according to an embodiment of the present invention; Figure 2 This is a flowchart of the control method for a carbon dioxide energy storage system according to an embodiment of the present invention. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the present invention clearer, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Examples of these preferred embodiments are illustrated in the drawings. The embodiments of the present invention shown in and described with reference to the drawings are merely exemplary, and the present invention is not limited to these embodiments.

[0018] It should be noted that the same or similar reference numerals in the accompanying drawings of the embodiments of the present invention correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," and "right" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the accompanying drawings are only for illustrative purposes and should not be construed as limiting the present patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0019] It should also be noted that, in order to avoid obscuring the invention with unnecessary details, only the structures and / or processing steps closely related to the solution according to the invention are shown in the accompanying drawings, while other details that are not closely related to the invention are omitted.

[0020] See Figure 1 The present invention first provides a working fluid energy compensation device 50 and a carbon dioxide energy storage system 100 including the working fluid energy compensation device 50.

[0021] Specifically, the carbon dioxide energy storage system 100 mainly includes a gas storage unit 10, an energy storage component 20, a liquid storage unit 30, and an energy release component 40 connected in a closed loop. The gas storage unit 10 stores gaseous carbon dioxide at atmospheric pressure, and the liquid storage unit 30 stores liquid carbon dioxide. Gaseous carbon dioxide flowing from the gas storage unit 10 is converted into liquid carbon dioxide at a preset energy storage pressure by the energy storage component 20 and flows into the liquid storage unit 30, completing energy storage in this process. Liquid carbon dioxide output from the liquid storage unit 30 releases energy through the energy release component 40, converting back into gaseous carbon dioxide at atmospheric pressure, and flows into the gas storage unit 10, completing energy release and application in this process. Typically, during off-peak electricity demand periods or by utilizing wind and solar power curtailment, the energy storage component 20 compresses and liquefies gaseous carbon dioxide into liquid carbon dioxide, storing it in the liquid storage unit 30, converting energy into compressible energy and thermal energy for storage. During peak electricity demand periods, the energy release component 40 vaporizes and expands the liquid carbon dioxide, releasing the stored energy and converting it into electrical energy for use.

[0022] The specific composition and structure of the gas storage unit 10, the energy storage component 20, the liquid storage unit 30, and the energy release component 40 can be implemented with reference to existing technologies, such as the technical solutions disclosed in existing patent documents CN116221616A, CN117628836A, and CN116857027A.

[0023] As a specific example, in this embodiment, such as Figure 1 As shown, the energy storage component 20 mainly includes a low-pressure compressor 21, an interstage heat exchanger 22, a high-pressure compressor 23, a post-stage heat exchanger 24, and a condenser 25, which are connected sequentially between the gas storage unit 10 and the liquid storage unit 30. In the compression heat release energy storage circuit, gaseous carbon dioxide undergoes two stages of compression through the low-pressure compressor 21 and the high-pressure compressor 23, and is then liquefied by the condenser 25 to form liquid carbon dioxide, which is stored in the liquid storage unit 30.

[0024] As a specific example, in this embodiment, such as Figure 1As shown, the energy release assembly 40 mainly includes an evaporator 41, a superheater 42, a high-pressure turbine 43, a reheater 44, and a low-pressure turbine 45 connected sequentially between the liquid storage unit 30 and the gas storage unit 10. In the heat absorption and expansion energy release circuit, liquid carbon dioxide absorbs heat and vaporizes in the evaporator 41, then performs work (e.g., generates electricity) through the high-pressure turbine 43 and the low-pressure turbine 45, releasing energy and transforming into atmospheric pressure gaseous carbon dioxide stored in the gas storage unit 10.

[0025] In the energy release component 40 of the carbon dioxide energy storage system 100, energy is released from the energy release heat exchanger (e.g. Figure 1 The outlets of the superheater 42 and reheater 44 are connected to the turbine (e.g., Figure 1 The gas delivery pipelines at the inlets of the high-pressure turbine 43 and the low-pressure turbine 45 are relatively long. After being heated by the energy release heat exchanger, the carbon dioxide gas experiences varying degrees of temperature and pressure reduction upon reaching the turbine inlet, resulting in energy loss of the working fluid. This often leads to the input working fluid energy value at the turbine inlet failing to reach the system setpoint, causing the turbine's operating efficiency to fall short of the design value and affecting the system's operational stability. In particular, because the energy storage and energy release processes occur separately, the carbon dioxide energy storage system 100 operates intermittently. Its operation is mainly divided into three stages: energy storage, resting, and energy release. During the non-energy release stage, the relevant gas delivery pipelines in the energy release component 40 are in a resting state, resulting in a greater decrease in the temperature and pressure of the carbon dioxide gas in the pipelines and a greater loss of working fluid energy. Therefore, when starting up and entering the energy release phase, the energy of the working medium input from the gas pipeline to the turbine inlet is insufficient to meet the turbine's operating efficiency requirements, resulting in a longer turbine start-up time. This not only reduces the working efficiency of the carbon dioxide energy storage system but also leads to a slower response speed of the carbon dioxide energy storage system to the upper-level control center (such as the upper-level power grid dispatch center).

[0026] To address the aforementioned problems, this invention provides a working fluid energy compensation device 50, primarily used in a carbon dioxide energy storage system 100, i.e., see [reference needed]. Figure 1 The carbon dioxide energy storage system 100 provided in the above embodiment of the present invention also includes a working fluid energy compensation device 50.

[0027] Specifically, such as Figure 1As shown, the working fluid energy compensation device 50 mainly includes a compressor 51 and a state parameter acquisition unit 52. The input end of the compressor 51 is connected to the gas storage unit 10, and the output end of the compressor 51 is connected to the turbine's input pipeline. The state parameter acquisition unit 52 is connected to the input pipeline. The state parameter acquisition unit 52 is configured to detect and acquire the state parameters of the carbon dioxide gas in the input pipeline, and calculate and determine the input working fluid energy value input to the turbine's inlet based on the state parameters. The compressor 51 is configured to, when the input working fluid energy value fails to reach the preset working fluid energy value, compress the carbon dioxide gas in the gas storage unit 10 and input it into the input pipeline to supplement the working fluid energy, so that the input working fluid energy value reaches the preset working fluid energy value. The preset working fluid energy value is the input working fluid energy value set by the system to ensure that the turbine's operating efficiency reaches the efficiency design value.

[0028] Based on the working fluid energy compensation device 50 described above, during the energy release phase of the energy storage system, the state parameter acquisition unit 52 detects and acquires the state parameters of the carbon dioxide gas in the input pipeline in real time, and calculates and determines the input working fluid energy value to the turbine inlet. When the input working fluid energy value fails to reach the preset working fluid energy value, the compression mechanism 51 compresses the carbon dioxide gas in the gas storage unit 10 and inputs it into the input pipeline to replenish the working fluid energy in a timely manner, so that the input working fluid energy value can reach the preset working fluid energy value, ensuring that the turbine's operating efficiency can reach the efficiency design value, and improving the overall efficiency and stability of the carbon dioxide energy storage system. In particular, when the energy storage system starts from the non-energy release phase and enters the energy release phase, the compression mechanism 51 can compress the carbon dioxide gas in the gas storage unit 10 and replenish the working fluid energy, including thermal energy and pressure energy, in a timely manner, greatly shortening the turbine start-up time. This not only improves the working efficiency of the carbon dioxide energy storage system, but also improves the response speed of the carbon dioxide energy storage system to the upper-level control center (such as the upper-level power grid dispatch center).

[0029] As described above, in this embodiment, the energy release assembly 40 includes a superheater 42, a high-pressure turbine 43, a reheater 44, and a low-pressure turbine 45 connected in sequence. The high-pressure turbine 43 is connected to the superheater 42 via a first input pipe 46, and the low-pressure turbine 45 is connected to the reheater 44 via a second input pipe 47. Therefore, in this embodiment, as... Figure 1As shown, the output end of the compressor 51 is interconnected with the first input line 46 corresponding to the high-pressure turbine 43 and the second input line 47 corresponding to the low-pressure turbine 45. The state parameter acquisition unit 52 is also interconnected with the first input line 46 and the second input line 47. The state parameter acquisition unit 52 is configured to: detect and acquire the state parameters of carbon dioxide gas in the first input line 46 and the second input line 47, and calculate and determine the input working fluid energy values ​​input to the inlet of the high-pressure turbine 43 and the inlet of the low-pressure turbine 45 based on the state parameters. The compressor 51 is configured as follows: (1) When the input working fluid energy value input to the inlet of the high-pressure turbine 43 fails to reach the preset working fluid energy value of the high-pressure turbine 43, the carbon dioxide gas in the gas storage unit 10 is compressed and input to the first input pipeline 46 to supplement the working fluid energy, so that the input working fluid energy value input to the high-pressure turbine 43 reaches the preset working fluid energy value of the high-pressure turbine 43. (2) When the input working fluid energy value input to the inlet of the low-pressure turbine 45 fails to reach the preset working fluid energy value of the low-pressure turbine 45, the carbon dioxide gas in the gas storage unit 10 is compressed and input to the second input pipeline 47 to supplement the working fluid energy, so that the input working fluid energy value input to the low-pressure turbine 45 reaches the preset working fluid energy value of the low-pressure turbine 45. (3) When the input working fluid energy values ​​input to the inlet of the high-pressure turbine 43 and the inlet of the low-pressure turbine 45 fail to reach the preset working fluid energy values ​​of the corresponding turbines, the carbon dioxide gas in the gas storage unit 10 is compressed and input to the input pipeline of the corresponding turbine to supplement the working fluid energy, so that the input working fluid energy values ​​input to the high-pressure turbine 43 and the low-pressure turbine 45 can reach the preset working fluid energy values.

[0030] It should be noted that in some other embodiments, the energy release component 40 may include a greater number of turbines connected in sequence. This can be understood as follows: the energy release component 40 includes a first-stage turbine to an Nth-stage turbine connected in sequence. In this case, the output end of the compressor 51 is interconnected with the input pipelines of each stage of the turbine, and the state parameter acquisition unit 52 is interconnected with the input pipelines of each stage of the turbine. Accordingly, the state parameter acquisition unit 52 is configured to: detect and acquire the state parameters of carbon dioxide gas in the input pipelines of each stage of the turbine, and calculate and determine the input working fluid energy value input to the inlet of each stage of the turbine based on the state parameters; the gas compression mechanism 51 is configured to: when the input working fluid energy value input to the inlet of the nth stage turbine fails to reach the preset working fluid energy value of the nth stage turbine, compress the carbon dioxide gas in the gas storage unit 10 and input it to the input pipeline corresponding to the nth stage turbine to supplement the working fluid energy, so that the input working fluid energy value input to the nth stage turbine reaches the preset working fluid energy value of the nth stage turbine; where N is an integer greater than or equal to 2, and n = 1, 2, ..., N.

[0031] In this embodiment, the state parameters include the pressure, temperature, and flow rate of carbon dioxide gas. The compressor 51 controls the energy of the working medium supplied to the input pipeline by adjusting the pressure and / or temperature and / or flow rate of the output compressed carbon dioxide gas. The state parameter acquisition unit 52 includes a parameter processing module and pressure sensors, temperature sensors, and flow meters (not shown in the figures) connected to the input pipelines of each turbine stage. The pressure sensors, temperature sensors, and flow meters detect and acquire the pressure, temperature, and flow rate parameters of carbon dioxide gas in each input pipeline in real time, and transmit them to the parameter processing module for data acquisition and processing.

[0032] As described in the above embodiment, the working fluid energy compensation device 50 can detect and acquire the input working fluid energy value of each turbine inlet in real time. When the input working fluid energy value of any turbine inlet fails to reach the preset working fluid energy value, the device can selectively supplement the working fluid energy in the input pipeline of that turbine inlet, thereby improving the accuracy of working fluid energy supplementation and further improving the efficiency of system operation.

[0033] In the specific design, the output end of the compressor 51 is connected to a main output line 60, which in turn connects to N output branches. The main output line 60 is connected to the input line corresponding to the nth stage turbine via the nth output branch. Furthermore, each output branch is equipped with a control valve 71 and a check valve 72. Figure 1As shown, in this embodiment, the main output line 60 is connected to the first input line 46 corresponding to the high-pressure turbine 43 via a first output branch 61, and the main output line 60 is connected to the second input line 47 corresponding to the low-pressure turbine 45 via a second output branch 62. A control valve 71 and a check valve 72 are respectively installed on the first output branch 61 and the second output branch 62. By controlling the control valve 71 on the corresponding output branch, compressed carbon dioxide gas can be selectively supplied to the corresponding input line and its flow rate can be controlled.

[0034] Furthermore, in this embodiment, as Figure 1 As shown, the input end of the air compressor 51 is connected to the air storage unit 10 through the connecting pipe 63, and a control valve 71 is also provided on the connecting pipe 63.

[0035] In this embodiment, as Figure 1 As shown, the working fluid energy compensation device 50 also includes a control unit 53. The gas compression mechanism 51 and the state parameter acquisition unit 52 are electrically connected to the control unit 53. The state parameter acquisition unit 52 feeds back the detected state parameters to the control unit 53. The control unit 53 calculates and determines the input working fluid energy value at the turbine inlet based on the state parameters and judges whether the preset working fluid energy value has been reached. When the input working fluid energy value fails to reach the preset working fluid energy value, the control unit 53 controls the gas compression mechanism 51 to compress the carbon dioxide gas in the gas storage unit 10 and input it into the input pipeline to supplement the working fluid energy.

[0036] As a preferred embodiment, the driving power for the air compressor 51 mainly comes from a photovoltaic power generation system or a wind power generation system, particularly utilizing wind and solar power curtailment. Of course, this power can also come from the power grid or other inexpensive power sources.

[0037] Based on the working fluid energy compensation device 50 and its corresponding carbon dioxide energy storage system 100 provided in the above embodiments, this embodiment of the invention also provides a control method for the carbon dioxide energy storage system 100. (See also...) Figure 2 The control method includes the following steps: S101, the state parameter acquisition unit 52 monitors and acquires the state parameters of carbon dioxide gas in the input pipeline in real time, and calculates and determines the energy value of the input working fluid input to the inlet of the turbine based on the state parameters.

[0038] S102. When the input working fluid energy value fails to reach the preset working fluid energy value, the compressor 51 is controlled to compress the carbon dioxide gas in the gas storage unit 10 and input it into the input pipeline to supplement the working fluid energy, so that the input working fluid energy value reaches the preset working fluid energy value.

[0039] As mentioned above, in this embodiment, as a preferred solution, the working fluid energy compensation device 50 further includes a control unit 53, and the control method specifically includes the following steps: S201, the status parameter acquisition unit 52 monitors and acquires the status parameters of carbon dioxide gas in the input pipeline in real time and feeds them back to the control unit 53.

[0040] S202, the control unit 53 calculates and determines the input working fluid energy value at the inlet of the turbine based on the state parameters and determines whether the preset working fluid energy value has been reached.

[0041] S203. When the input working fluid energy value fails to reach the preset working fluid energy value, the control unit 53 calculates and determines the working fluid energy that needs to be supplemented and sends a control command to the compressor 51.

[0042] S204. The gas compression mechanism 51 compresses the carbon dioxide gas in the gas storage unit 10 and inputs it into the input pipeline according to the control command to supplement the working medium energy, so that the input working medium energy value reaches the preset working medium energy value.

[0043] It should be noted that the preset working fluid energy value needs to be set according to the actual needs of the energy storage system. Different preset working fluid energy values ​​can be set for different operating stages. For example, corresponding to the start-up stage and stable operation stage of the energy release component 40, the corresponding preset working fluid energy values ​​can be set for control.

[0044] In summary, the working fluid energy compensation device, carbon dioxide energy storage system, and control method provided in the above embodiments of the present invention, during the operation of the energy storage system, obtain the state parameters of carbon dioxide gas in the input pipeline in real time through the state parameter acquisition unit, and calculate and determine the input working fluid energy value input to the turbine inlet; when the input working fluid energy value fails to reach the preset working fluid energy value, the carbon dioxide gas in the gas storage unit is compressed by the gas compression mechanism and input into the input pipeline to replenish the working fluid energy in a timely manner, so that the input working fluid energy value can reach the preset working fluid energy value, ensuring that the turbine's operating efficiency can reach the efficiency design value, and improving the overall efficiency and stability of the carbon dioxide energy storage system.

[0045] The above description is only a specific embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A working fluid energy compensation device, applied to a carbon dioxide energy storage system, wherein the carbon dioxide energy storage system comprises a gas storage unit, an energy storage component, a liquid storage unit and an energy release component connected in a closed loop in sequence, characterized in that: The working fluid energy compensation device includes a gas compression mechanism and a state parameter acquisition unit, the energy release component includes a turbine, the input end of the gas compression mechanism is connected to the gas storage unit, the output end of the gas compression mechanism is connected to the input pipeline of the turbine, and the state parameter acquisition unit is connected to the input pipeline; wherein, The state parameter acquisition unit is configured to: detect and obtain the state parameter of the carbon dioxide gas in the input pipeline, and calculate and determine the input working fluid energy value input to the inlet of the turbine based on the state parameter; The gas compression mechanism is configured to: when the input working fluid energy value fails to reach the preset working fluid energy value, compress the carbon dioxide gas in the gas storage unit and input it into the input pipeline to supplement the working fluid energy, so that the input working fluid energy value reaches the preset working fluid energy value; The preset working fluid energy value is the input working fluid energy value set by the system so that the operating efficiency of the turbine can reach the efficiency design value.

2. The working fluid energy compensation device according to claim 1, characterized in that: The energy release assembly includes a first-stage turbine to an N-stage turbine connected in sequence, the output end of the air compression mechanism is interconnected with the input pipelines of the turbines at each stage, and the state parameter acquisition unit is interconnected with the input pipelines of the turbines at each stage; The state parameter acquisition unit is configured to: detect and obtain the state parameters of the carbon dioxide gas in the input pipeline of each stage of the turbine, and calculate and determine the energy value of the input working fluid input to the inlet of each stage of the turbine based on the state parameters; The gas compression mechanism is configured to: when the input working fluid energy value input to the inlet of the n-th stage turbine fails to reach the preset working fluid energy value of the n-th stage turbine, the carbon dioxide gas in the gas storage unit is compressed and input to the input pipeline corresponding to the n-th stage turbine to supplement the working fluid energy, so that the input working fluid energy value input to the inlet of the n-th stage turbine reaches the preset working fluid energy value of the n-th stage turbine; Here, N is an integer greater than or equal to 2, n=1, 2, …, N.

3. The working fluid energy compensation device according to claim 2, characterized in that: The output end of the air compression mechanism is connected to an output main pipeline, the output main pipeline is connected to N output branches, and the output main pipeline is connected to the input pipeline corresponding to the n-th stage turbine through the n-th output branch.

4. The working fluid energy compensation device according to claim 3, characterized in that: Each of the output branches is respectively provided with a control valve and a check valve.

5. The working fluid energy compensation device according to any one of claims 1 to 4, characterized in that: The working fluid energy compensation device also includes a control unit, the air compression mechanism and the state parameter acquisition unit are respectively connected to the control unit with electrical signals, the state parameter acquisition unit feeds back the detected state parameters to the control unit, and the control unit calculates and determines the input working fluid energy value input to the inlet of the turbine based on the state parameters and determines whether it reaches the preset working fluid energy value; when the input working fluid energy value fails to reach the preset working fluid energy value, the control unit controls the air compression mechanism to compress the carbon dioxide gas in the gas storage unit and input it into the input pipeline to supplement the working fluid energy.

6. The working fluid energy compensation device according to claim 5, characterized in that: The state parameters include the pressure, temperature and flow rate of the carbon dioxide gas. The gas compression mechanism controls the energy of the working fluid added to the input pipeline by adjusting the pressure and / or temperature and / or flow rate of the output compressed carbon dioxide gas.

7. The working fluid energy compensation device according to claim 1, characterized in that: The driving electric energy of the air compression mechanism comes from a photovoltaic power generation system or a wind power generation system.

8. A carbon dioxide energy storage system, comprising a gas storage unit, an energy storage component, a liquid storage unit and an energy release component connected in a closed loop, characterized in that: The carbon dioxide energy storage system also includes a working fluid energy compensation device as described in any one of claims 1-7.

9. A control method for a carbon dioxide energy storage system as claimed in claim 8, characterized in that: include: The state parameter acquisition unit monitors and acquires the state parameters of the carbon dioxide gas in the input pipeline in real time, and calculates and determines the energy value of the input working fluid input to the inlet of the turbine based on the state parameters; When the input working fluid energy value fails to reach the preset working fluid energy value, the gas compression mechanism is controlled to compress the carbon dioxide gas in the gas storage unit and input it into the input pipeline to supplement the working fluid energy, so that the input working fluid energy value reaches the preset working fluid energy value.

10. The control method according to claim 9, characterized in that: The working fluid energy compensation device further includes a control unit, and the control method includes: The state parameter acquisition unit monitors and obtains the state parameters of the carbon dioxide gas in the input pipeline in real time and feeds back the state parameters to the control unit; The control unit calculates and determines the input working fluid energy value input to the inlet of the turbine based on the state parameter and determines whether it reaches the preset working fluid energy value; When the input working fluid energy value fails to reach the preset working fluid energy value, the control unit calculates and determines the working fluid energy that needs to be supplemented and issues a control instruction to the air compression mechanism; According to the control instruction, the gas compression mechanism compresses the carbon dioxide gas in the gas storage unit and inputs it into the input pipeline to supplement the working fluid energy, so that the input working fluid energy value reaches the preset working fluid energy value.

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