A normalized evaluation method for cycle efficiency of compressed air energy storage system
Patent Information
- Application Number
- CN202611166767.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-08-03
- Publication Date
- 2026-10-27
AI Technical Summary
然而，该类系统也面临运行中储气装置内空气参数动态变化的问题，加之CAES商业化运行实践较少，运行人员经验不足，使系统性能的实时评估与运行优化面临较大挑战
[0021]本申请的有益效果在于：针对压缩空气储能系统循环效率实时评价难、系统效率损失量化不直观的问题，通过引入以盐穴压力、压缩机电机总电流累积值及剩余储能能力为特征变量，构建归一化循环效率评价方法，实现了系统循环过程中性能的实时评价和展示分析。本申请通过循环历史数据与实时运行数据的对比分析，能够直观反映系统当前运行效率的偏差情况与能量损耗，更好地为运行调度与能效优化提供可靠支撑。
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Figure CN122986224A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the fields of new energy and energy-saving technologies, and in particular to a normalized evaluation method for the cycle efficiency of a compressed air energy storage system. Background Technology
[0002] According to the International Energy Agency's forecast, global renewable energy installed capacity is expected to approach 11,000 GW by 2030, with China accounting for over 40%. While large-scale grid connection of renewable energy provides abundant low-carbon and clean electricity, the intermittency and volatility of its generation capacity also put significant pressure on grid peak shaving. Furthermore, renewable energy generation is highly dependent on power electronic devices—particularly evident in wind and solar power—leading to a decrease in the overall rotational inertia of the power system and reduced stability. Compressed air energy storage (CAES), as an energy storage technology with large-scale construction potential, is considered one of the feasible solutions to these problems. CAES has comprehensive advantages such as large capacity, low investment cost, short construction period, and long service life.
[0003] High-temperature adiabatic compressed air energy storage systems (CAES), as a typical form of non-combustion-based CAES, encompass two main stages of operation: compression energy storage and expansion energy release. During compression, electricity drives a compressor to compress and store air, simultaneously preserving the generated heat. In the expansion stage, the stored heat is fed back to the high-pressure air through a heat exchanger, driving a turbine to generate electricity; the entire process is clean and carbon-free. However, these systems also face the challenge of dynamic changes in air parameters within the storage device during operation. Furthermore, the limited commercial operation experience of CAES and the lack of operational expertise among personnel pose significant challenges to real-time performance evaluation and operational optimization.
[0004] Existing methods for monitoring the operation of compressed air energy storage systems primarily focus on displaying single-point parameters such as pressure, temperature, and power, making it difficult to intuitively reflect performance changes and sources of loss throughout the complete energy storage-release cycle. For operators, relying solely on instantaneous power or single-cycle efficiency is insufficient to promptly determine the differences between the current cycle and historical cycles, and it is also difficult to quantify the system's efficiency deviation across different salt cavern pressure ranges. Therefore, it is necessary to propose a method that unifies the energy storage and release processes under the same process coordinate system, and that can intuitively characterize the system's cycle efficiency through graphical closure and area difference. This would help operators quickly and intuitively analyze the system's current operating status, enabling targeted decision-making, further enhancing the level of intelligence in this field, and facilitating the marketization and large-scale application of new energy storage technologies. This will also accelerate the construction of new power systems. Summary of the Invention
[0005] This application provides a normalized evaluation method for the cycle efficiency of a compressed air energy storage system. The technical objective is to select salt cavern pressure as the independent variable in the system cycle process, and the cumulative total compressor current and remaining energy storage capacity as the system state dependent variables for the energy storage and release processes, respectively. A normalization method is used to close the two curves, and the difference between their integrals represents the loss in one cycle. Simultaneously, during the cycle, real-time evaluation of system performance is achieved by comparing the system with the curves of the previous cycle and the historical best cycle.
[0006] The above-mentioned technical objective of this application is achieved through the following technical solution:
[0007] A normalized evaluation method for the cycle efficiency of a compressed air energy storage system includes the following steps:
[0008] S1: Data acquisition and data preprocessing;
[0009] S2: Data normalization and drawing of the cycle performance analysis diagram of compressed air energy storage system;
[0010] S3: Chart display and system efficiency analysis methods.
[0011] Further, step S1 includes:
[0012] S11: Obtain current operating data from the real-time data communication interface of the distributed control system (DCS) and obtain historical operating data from the historical database.
[0013] The current operating data includes compressor motor current values, cavern pressure, and timestamps for each stage during the energy storage phase, and load dispatch instructions, cavern pressure, and timestamps for the future period during the energy release phase. Historical operating data includes the stored cumulative total compressor current, remaining energy storage capacity, and corresponding cavern pressure for the previous cycle and the best historical cycle.
[0014] S12: Perform data preprocessing on the current operating data. For the energy storage phase, data preprocessing includes summing the currents of each compressor segment to obtain the total current value, and then integrating the total current value over time to obtain the cumulative total current value. For the energy release phase, data preprocessing includes calculating the remaining energy storage capacity of the system using load dispatch commands and pre-stored system pressure-flow mapping characteristic curves.
[0015] Further, step S2 includes:
[0016] S21: The cumulative total compressor current and remaining energy storage capacity from the previous cycle and the historical best cycle are respectively subjected to minimum-maximum normalization. The cumulative total compressor current and remaining energy storage capacity at the highest salt cavern pressure are taken as the maximum values, and the cumulative total compressor current and remaining energy storage capacity at the highest salt cavern pressure are taken as the minimum values. After determining the minimum and maximum values using the previous cycle and the historical best cycle, the current actual operating data is also normalized. This achieves the goal of closing the energy storage / release process operating curve, visually displaying the cycle's operating status.
[0017] S22: Using salt cavern pressure as the horizontal axis and the normalized cumulative total compressor current and remaining energy storage capacity as the vertical axis, the compressed air energy storage system cycle performance analysis chart is drawn using three different colors for the previous cycle, the historical best cycle, and the current operating data.
[0018] Further, step S3 includes:
[0019] S31: The compressed air energy storage system cycle performance analysis diagram is sent to the shift supervisor's station via the real-time communication interface to help operators monitor the operating status.
[0020] S32: Based on the deviation between the current cycle curve and the previous cycle curve and the historical best cycle curve, calculate the cycle loss characterization quantity and the normalized cycle efficiency index, and analyze the reasons for the system efficiency deviation.
[0021] The beneficial effects of this application are as follows: Addressing the difficulties in real-time evaluation of the cycle efficiency of compressed air energy storage systems and the lack of intuitive quantification of system efficiency losses, this application introduces a normalized cycle efficiency evaluation method using salt cavern pressure, the cumulative total current of the compressor motor, and remaining energy storage capacity as characteristic variables. This enables real-time evaluation and visualization of system performance during the cycle. Furthermore, by comparing historical cycle data with real-time operating data, this application can intuitively reflect the deviation in the system's current operating efficiency and energy loss, providing better and more reliable support for operation scheduling and energy efficiency optimization. Attached Figure Description
[0022] Figure 1 This is a flowchart of the method described in this application; Detailed Implementation
[0023] The technical solution of this application will now be described in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the scope of the invention.
[0024] like Figure 1 As shown, this invention provides a normalized evaluation method for the cycle efficiency of a compressed air energy storage system, comprising the following steps:
[0025] S1: Data acquisition and data preprocessing;
[0026] Further, step S1 includes:
[0027] S11: Obtain current operating data from the DCS's real-time communication interface and historical operating data from the historical database.
[0028] The current operating data in the energy storage phase includes the current values of the compressor motors in each stage. , , Salt cavern pressure And sampling time, including load dispatch instructions for a future period during the energy release phase. Salt cavern pressure And sampling time. Historical operating data includes the stored cumulative total compressor current, remaining energy storage capacity, and salt cavern pressure at the corresponding moment for the previous cycle and the historical best cycle.
[0029] S12: Perform data preprocessing on the current operating data. For the energy storage stage, data preprocessing includes summing the currents of each compressor stage to obtain the total current value. :
[0030]
[0031] Then, the total current value is obtained by integrating the total current value over time:
[0032]
[0033] in, This represents the cumulative total current of the compressor during the energy storage phase. This marks the start of the energy storage phase. The cumulative total current of the compressor reflects the cumulative trend of electrical energy input during the energy storage phase.
[0034] For the energy release phase, data preprocessing includes calculating the system's remaining energy storage capacity using load dispatch commands and pre-stored system pressure-flow mapping characteristic curves. Specifically, the salt cavern pressure is pre-established. With available airflow Mapping relationship between them:
[0035]
[0036] in, This relates to the system's pressure-flow mapping characteristics. Based on the available generating capacity or dispatchable capacity after the current moment, calculate the remaining energy release capacity:
[0037]
[0038] in, For a moment The remaining energy release capacity, During the energy release phase, the power that can be output is... This marks the end of the energy release phase. From this, we obtain the energy release phase state curve corresponding to the salt cavern pressure.
[0039] S2: Data normalization and drawing of the cycle performance analysis diagram of compressed air energy storage system;
[0040] Further, step S2 includes:
[0041] S21: The cumulative total compressor current and remaining energy storage capacity from the previous cycle and the historical best cycle are respectively subjected to minimum-maximum normalization. The cumulative total compressor current and remaining energy storage capacity at the highest salt cavern pressure are taken as the maximum values, and the cumulative total compressor current and remaining energy storage capacity at the highest salt cavern pressure are taken as the minimum values. After determining the minimum and maximum values using the previous cycle and the historical best cycle, the current actual operating data is also normalized. This achieves the goal of closing the energy storage / release process operating curve, visually displaying the cycle's operating status.
[0042] For the cumulative total current of the compressor during the energy storage phase, the normalized value is as follows:
[0043]
[0044] in, This is the normalized curve for the energy storage stage. The pressure of the salt cavern is The corresponding cumulative total compressor current at that time. and These are the minimum and maximum cumulative total current values of the compressor within the same cycle or reference cycle pressure range, respectively.
[0045] The remaining energy release capacity during the energy release phase is normalized as follows:
[0046]
[0047] in, This is the normalized curve for the energy release phase. The pressure of the salt cavern is The corresponding remaining energy release capacity at that time and These represent the minimum and maximum residual energy release capacity within the same cycle or reference cycle pressure range, respectively.
[0048] After the above normalization process, the energy storage stage curve and the energy release stage curve are at the lower limit of the salt cavern pressure. and upper limit of salt cavern pressure They have consistent endpoints, thus forming a closed loop. Using salt cavern pressure as the x-axis, and... and Using the vertical axis, plot the cyclic performance analysis diagram of the compressed air energy storage system; simultaneously, plot the corresponding curves of the current cycle, the previous cycle, and the historical best cycle on the same graph to visually demonstrate the changes in system performance.
[0049] S22: Using salt cavern pressure as the horizontal axis and the normalized cumulative total compressor current and remaining energy storage capacity as the vertical axis, the compressed air energy storage system cycle performance analysis chart is drawn using three different colors for the previous cycle, the historical best cycle, and the current operating data.
[0050] S3: Methods for chart visualization and system efficiency analysis;
[0051] Further, step S3 includes:
[0052] S31: The compressed air energy storage system cycle performance analysis diagram is sent to the shift supervisor's station via the real-time communication interface to help operators monitor the operating status.
[0053] S32: Based on the deviation between the current cycle curve and the previous cycle curve and the historical best cycle curve, calculate the cycle loss characterization quantity and the normalized cycle efficiency index, and analyze the reasons for the system efficiency deviation.
[0054] Furthermore, to quantify the extent of loss in the current cycle, the area difference between the normalized curves of the energy storage phase and the energy release phase is calculated:
[0055]
[0056] in, This is a measure of cyclic loss. The larger the value, the more significant the deviation between the energy storage and energy release processes, and the greater the system cycle loss. The smaller the value, the closer the current loop performance is to the ideal closed state or the historical best state.
[0057] A normalized cycle efficiency index can also be constructed based on the cycle loss characterization:
[0058]
[0059] in, This is a normalized cycle efficiency index. This serves as a preset reference area or the area benchmark corresponding to the historical best cycle. This indicator allows curve deviations to be transformed into efficiency evaluation results that are easy for operators to understand and compare.
[0060] When the current cycle curve deviates significantly from the historical best cycle curve, the system can further determine the possible causes by considering the salt cavern pressure range where the deviation occurs. For example, if the energy storage stage curve shifts significantly upward in the high-pressure range, it may indicate increased energy consumption during compression or decreased compressor efficiency; if the energy release stage curve shifts significantly downward in the medium-low pressure range, it may indicate decreased energy release capacity, reduced expansion power generation efficiency, or a shift in pressure-flow characteristics.
[0061] In practice, deviation thresholds can be set according to operational management needs. Exceeding the preset threshold, or When the efficiency falls below a preset threshold, an efficiency deviation warning message is output to remind operators to conduct equipment status checks, adjust operating parameters, or optimize scheduling strategies.
[0062] The above description is merely a preferred embodiment of the present invention; other effective embodiments are also possible. Any effective improvements proposed by those skilled in the art based on the present invention should also be considered within the scope of protection of the present invention.
Claims
1. A normalized evaluation method for the cycle efficiency of a compressed air energy storage system, characterized in that, Includes the following steps: S1: Data acquisition and data preprocessing; S2: Data normalization and drawing of the cycle performance analysis diagram of compressed air energy storage system; S3: Chart display and system efficiency analysis methods.
2. The normalized evaluation method for the cycle efficiency of a compressed air energy storage system according to claim 1, characterized in that, Step S1 includes: S11: Obtain current operating data from the real-time communication interface of the distributed control system (DCS) and obtain historical operating data from the historical database; The current operating data includes the compressor motor current value, salt cavern pressure and sampling time in the energy storage stage, and the load dispatch command, salt cavern pressure and sampling time in the energy release stage; the historical operating data includes the total compressor current accumulation value, remaining energy storage capacity and corresponding salt cavern pressure of the previous cycle and the historical best cycle that have been stored. S12: Perform data preprocessing on the current operating data; for the energy storage stage, data preprocessing includes summing the currents of each compressor segment to obtain the total current value. : in, , and These are the motor current values for each section of the compressor; Then, the total current value is obtained by integrating the total current value over time: in, This represents the cumulative total current of the compressor during the energy storage phase. This marks the start of the energy storage phase; the cumulative total current of the compressor reflects the cumulative trend of electrical energy input during the energy storage phase. For the energy release phase, data preprocessing includes calculating the system's remaining energy storage capacity using load dispatch commands and pre-stored system pressure-flow mapping characteristic curves; specifically, the salt cavern pressure is pre-established. With available airflow Mapping relationship between them: in, For the system pressure-flow mapping characteristics, Salt cavern pressure, This is a load dispatch command; based on the generating capacity or dispatchable capacity after the current moment, calculate the remaining energy release capacity: in, For a moment The remaining energy release capacity, During the energy release phase, the power that can be output is... This marks the end of the energy release phase; thus, the state curve of the energy release phase corresponding to the salt cavern pressure is obtained.
3. The normalized evaluation method for the cycle efficiency of a compressed air energy storage system according to claim 1, characterized in that, Step S2 includes: S21: The cumulative total compressor current and remaining energy storage capacity of the previous cycle and the historical best cycle are respectively subjected to minimum-maximum normalization. The cumulative total compressor current and remaining energy storage capacity at the highest salt cavern pressure are taken as the maximum value, and the cumulative total compressor current and remaining energy storage capacity at the highest salt cavern pressure are taken as the minimum value. After determining the minimum and maximum values using the previous cycle and the historical best cycle, the current actual operating data are also normalized. This achieves the purpose of closing the operating curve of the energy storage / release process and intuitively showing the operating status of the cycle. For the cumulative total current of the compressor during the energy storage phase, the normalized value is as follows: in, This is the normalized curve for the energy storage stage. The pressure of the salt cavern is The corresponding cumulative total compressor current at that time. and These are the minimum and maximum cumulative values of the compressor's total current within the same cycle or reference cycle pressure range, respectively. The remaining energy release capacity during the energy release phase is normalized as follows: in, This is the normalized curve for the energy release phase. The pressure of the salt cavern is The corresponding remaining energy release capacity at that time and These represent the minimum and maximum residual energy release capacity within the same cycle or reference cycle pressure range, respectively. After the above normalization process, the energy storage stage curve and the energy release stage curve are at the lower limit of the salt cavern pressure. and upper limit of salt cavern pressure The points have consistent endpoints, thus forming a closed loop; with salt cavern pressure as the x-axis, and... and Using the vertical axis, plot the cyclic performance analysis diagram of the compressed air energy storage system; simultaneously plot the corresponding curves of the current cycle, the previous cycle, and the historical best cycle on the same graph to visually demonstrate the changes in system performance. S22: Using salt cavern pressure as the horizontal axis and the normalized cumulative total compressor current and remaining energy storage capacity as the vertical axis, the compressed air energy storage system cycle performance analysis chart is drawn using three different colors for the previous cycle, the historical best cycle, and the current operating data.
4. The normalized evaluation method for the cycle efficiency of a compressed air energy storage system according to claim 3, characterized in that, Step S3 includes: S31: Send the compressed air energy storage system cycle performance analysis diagram to the shift supervisor's station via the real-time communication interface to help operators monitor the operating status; S32: Based on the deviation between the current cycle curve and the previous cycle curve and the historical best cycle curve, calculate the cycle loss characterization quantity and the normalized cycle efficiency index, and analyze the reasons for the system efficiency deviation.
5. The normalized evaluation method for the cycle efficiency of a compressed air energy storage system according to claim 4, characterized in that, To quantify the extent of loss in the current cycle, the area difference between the normalized curves for the energy storage phase and the energy release phase is calculated: in, This is a cyclic loss characterization measure; The larger the value, the more significant the deviation between the energy storage and energy release processes, and the greater the system cycle loss. The smaller the value, the closer the current loop performance is to the ideal closed state or the historical best state; A normalized cycle efficiency index was also constructed based on the cycle loss characterization: in, This is a normalized cycle efficiency index. This serves as a preset reference area or the area benchmark corresponding to the historical best cycle; through this indicator, curve deviation is transformed into an efficiency evaluation result that is easy for operators to understand and compare.