A construction method of super-structure Carnot cell energy storage power generation system

Abstract

The application provides a construction method of a super-structure Carnot cell energy storage power generation system, comprising the following steps: S1, designing a top cycle energy storage system to obtain a super-structure Carnot cell energy storage system; S2, designing a bottom cycle power generation system to obtain a super-structure Carnot cell power generation system; S3, combining the super-structure Carnot cell energy storage system and the super-structure Carnot cell power generation system to obtain a super-structure Carnot cell energy storage power generation system; S4, determining boundary parameters of the top cycle energy storage system; S5, calculating performance parameters of the top cycle energy storage system; S6, determining boundary parameters of the bottom cycle power generation system; S7, determining optimization variables and value ranges of the bottom cycle power generation system; S8, calculating performance parameters of the bottom cycle power generation system; S9, exploring influences of key parameters on the super-structure Carnot cell energy storage power generation system; S10, multi-objective optimization of the system; and S11, ending. The construction and optimization of the system can obtain optimal combined system cycle operation parameters.

Description

Technical Field

[0001] This invention relates to the field of power storage and power cycle technology, and more particularly to a method for constructing a superstructured Carnot battery energy storage and power generation system. Background Technology

[0002] In my country's current energy structure, coal-fired power generation still accounts for a large proportion, resulting in a large amount of carbon emissions and energy loss. In order to make efficient use of energy, waste heat recovery technology is currently the most popular and effective technical means.

[0003] Recently, due to its high efficiency, stable operation, and compact size, the supercritical carbon dioxide Brayton cycle system has been widely regarded as a strong competitor to the traditional Rankine cycle system in the field of waste heat recovery. However, the mainstream research method for optimizing supercritical CO2 cycle systems in waste heat recovery is still the traditional enumeration method. This method often fails to fully consider the influence of the cycle configuration when optimizing the optimal design parameters of the supercritical CO2 cycle system.

[0004] Since the loop configuration and design parameters need to be optimized step by step, traditional enumeration methods are inadequate when faced with a large number of loop configurations and are prone to missing the optimal loop configuration. Although enumeration methods are intuitive, easy to understand, and can guarantee finding the exact optimal solution, their drawbacks include a large computational load and low problem-solving efficiency, especially when the enumeration space is large, sometimes even making it impossible to solve with existing computing tools. Therefore, in the optimization design of supercritical CO2 cyclic systems, exploring more efficient optimization methods while considering the interaction between loop configuration and design parameters is of great significance for improving system performance and optimization efficiency.

[0005] The superstructure method is a top-down approach that adds additional components such as coolers, compressors, regenerators, heat exchangers, and expander generators to a traditional supercritical CO2 power cycle system, integrating as many system configurations as possible into a single large system. Therefore, the superstructure method is employed to achieve synergistic optimization of the structural and design parameters of the supercritical CO2 power cycle system through superstructure. By constructing and optimizing a novel superstructure-based supercritical CO2 power cycle, the influence of boundary conditions and equipment parameters on the optimal cycle configuration can be clearly defined. This method not only improves design efficiency but also better adapts to complex system requirements, thereby enhancing overall performance and economy.

[0006] Similarly, the superstructure method can also be applied to the configuration of Carnot battery energy storage systems, integrating multiple energy storage system configurations into a large system to achieve energy storage for various operating conditions. Compared with traditional Carnot battery energy storage systems, this type of Carnot battery energy storage system is more practical and has a wider range of applications.

[0007] Carnot battery energy storage technology is a technology that uses thermal energy to store electrical energy. It has advantages such as being unrestricted by geographical conditions, high energy density, and ease of implementing multi-energy supply. Currently, Carnot battery energy storage technology has made great progress, and many specific Carnot battery systems have been successfully put into operation.

[0008] However, no one has designed or optimized the combined use of Carnot battery energy storage systems with supercritical CO2 power cycle systems. For example, Shi et al. (invention title: Carnot Battery Energy Storage System and Usage Method, application publication number CN115095402A) described in detail a Carnot battery energy storage system and its usage method that efficiently utilizes low-grade industrial waste heat. This Carnot battery energy storage system can be flexibly applied to various industrial scenarios. However, it did not combine it with a supercritical CO2 power cycle system. Zhang et al. (invention title: A Direct Cooling System for Marine Generators Based on Supercritical CO2 Power Cycle, application publication number CN118920766A) provided a direct cooling system for marine generators based on a supercritical carbon dioxide power cycle, which can improve the compactness and lightweighting of marine power waste heat power generation systems. However, there was no further discussion on how to optimize the configuration of the supercritical CO2 power cycle system, nor was the Carnot battery energy storage system integrated. Liu et al. (invention title: A dual-backpressure supercritical carbon dioxide polygeneration system and operation method, application publication number CN112554980A) proposed a dual-backpressure supercritical carbon dioxide polygeneration system and operation method. The system mainly includes a low-backpressure power generation circuit consisting of a turbine, a two-stage main compressor, a re-compressor, a multi-stage regenerator, a cooler, and a boiler; and a high-backpressure circuit where turbine exhaust gas is used for heating network supply after being released by the two-stage regenerator. In terms of CO2 compression, multi-stage compression with diversion was carried out, but there was no further discussion on cooling, heating, and regeneration.

[0009] Therefore, there is currently no effective method to combine multiple Carnot battery energy storage systems with multiple Carnot battery power generation systems, optimize their configurations, and apply them to the land and shipping industries.

[0010] The research direction for workers in this field is to propose an effective and feasible thermodynamic structural method to construct a superstructured Carnot battery energy storage and power generation system, thereby forming a completely new superstructured energy storage and power generation system. Summary of the Invention

[0011] To address the aforementioned technical problems, a method for constructing a superstructured Carnot battery energy storage and power generation system is provided.

[0012] The technical means employed in this invention are as follows:

[0013] A method for constructing a superstructured Carnot battery energy storage and power generation system includes the following steps:

[0014] S1. Design a top-cycle energy storage system to obtain a superstructured Carnot battery energy storage system;

[0015] S2. Design a bottom-circulation power generation system to obtain a superstructured Carnot battery power generation system;

[0016] S3. Combine the superstructured Carnot battery energy storage system obtained in step S1 with the superstructured Carnot battery power generation system obtained in step S2 to obtain a superstructured Carnot battery energy storage power generation system.

[0017] S4. Determine the boundary parameters of the top-circulation energy storage system according to step S1;

[0018] S5. Based on step S4, calculate the performance parameters of the top-cycle energy storage system;

[0019] S6. Determine the boundary parameters of the bottom circulation power generation system according to step S3;

[0020] S7. Determine the optimization variables and value range of the bottom circulation power generation system according to step S3;

[0021] S8. Based on steps S6 and S7, calculate the performance parameters of the bottom cycle power generation system;

[0022] S9. Investigate the impact of key parameters on the superstructured Carnot battery energy storage and power generation system;

[0023] S10. Perform multi-objective optimization of the system;

[0024] S11, End.

[0025] Furthermore, in step S1, a superstructure Carnot battery energy storage system is formed by constructing multiple energy storage configurations and combining them.

[0026] In step S2, designing the bottom-cycle power generation system to obtain the superstructure Carnot battery power generation system specifically includes the following steps:

[0027] S21. Design the cold end, construct various cold end configurations, and combine them to form the cold end structure of the superstructured Carnot battery power generation cycle;

[0028] S22. Design the hot end, construct various hot end configurations, including heating end configuration and regenerative end configuration, and combine them to form the hot end structure of the superstructure Carnot battery power generation cycle;

[0029] S23. Combine the cold end structure formed in step S21 with the hot end structure formed in step S22 to obtain a superstructured Carnot battery power generation system.

[0030] Furthermore, the energy storage configuration has 10 types, the cold end structure has 5 types, and the hot end structure has 12 types. The superstructured Carnot battery energy storage and power generation system, which combines the 10 energy storage configurations with the 5 cold end structures and 12 hot end structures, can achieve 600 Carnot battery energy storage and power generation cycles.

[0031] Furthermore, in step S1, 10 energy storage configurations are constructed by means of multiple reheating, multiple compression, and multiple heat exchange; the 10 energy storage configurations include 5 single heat exchange structures and 5 secondary heat exchange structures.

[0032] The five single-cycle heat exchange structures include: single-cycle regeneration single-compression single-cycle heat exchange configuration, single-cycle regeneration double-compression single-cycle heat exchange configuration, double-cycle regeneration single-compression single-cycle heat exchange configuration, double-cycle regeneration double-compression single-cycle heat exchange configuration, and double-cycle regeneration triple-compression single-cycle heat exchange configuration.

[0033] The five secondary heat exchange structures include: single-cycle regeneration and single-cycle compression with secondary heat exchange, single-cycle regeneration and double-cycle compression with secondary heat exchange, double-cycle regeneration and single-cycle compression with secondary heat exchange, double-cycle regeneration and double-cycle compression with secondary heat exchange, and double-cycle regeneration and triple-cycle compression with secondary heat exchange.

[0034] Furthermore, in step S21, five cold-end structures are constructed by means of intermediate cooling to reduce compression power consumption; the five cold-end structures include: basic cooling configuration, split compression cooling configuration, pre-cooling cooling configuration, intermediate cooling configuration, and intermediate cooling split compression cooling configuration.

[0035] Furthermore, in step S22, 12 hot-end structures are constructed by means of CO2 diversion to improve heat exchange matching and multiple heating and reheating; the 12 hot-end structures include 4 single diversion structures and 8 double diversion structures;

[0036] The four single-split structures include: a configuration of secondary heating, single regeneration, and single expansion; a configuration of secondary heating, secondary regeneration, and single expansion; a configuration of secondary heating, single regeneration, and secondary expansion; and a configuration of secondary heating, secondary regeneration, and secondary expansion.

[0037] The eight dual-flow structures include: a secondary heating single-regeneration single-expansion configuration, a secondary heating double-regeneration double-expansion configuration, a tertiary heating double-regeneration single-expansion configuration, a tertiary heating double-regeneration double-expansion configuration, a secondary heating single-regeneration double-expansion configuration, a secondary heating double-regeneration triple-expansion configuration, a tertiary heating double-regeneration double-expansion configuration, and a tertiary heating double-regeneration triple-expansion configuration.

[0038] Further, in step S1, the superstructured Carnot battery energy storage system formed by the combination includes: an evaporator, a discrete splitter I, a preheater, a pre-compressor I, a continuous splitter I, a main reheater, a main compressor I, a split compressor I, a heat exchanger I, a heat storage tank I, a discrete splitter II, a heat exchanger II, a heat storage tank II, a condenser, and an expansion valve. The evaporator is connected to the discrete splitter I, the discrete splitter I is connected to the reheater, the preheater is connected to the pre-compressor I, the pre-compressor I is connected to the continuous splitter I, and the discrete splitter... Ⅰ is connected to continuous flow divider Ⅰ, continuous flow divider Ⅰ is connected to main regenerator, main regenerator is connected to main compressor Ⅰ, continuous flow divider Ⅰ is connected to flow divider compressor Ⅰ, main compressor Ⅰ is connected to heat exchanger Ⅰ, flow divider compressor Ⅰ is connected to heat exchanger Ⅰ, heat exchanger Ⅰ is connected to heat storage tank Ⅰ, heat exchanger Ⅰ is connected to discrete flow divider Ⅱ, discrete flow divider Ⅱ is connected to heat exchanger Ⅱ, heat exchanger Ⅱ is connected to heat storage tank Ⅱ, heat exchanger Ⅱ is connected to condenser, discrete flow divider Ⅱ is connected to condenser, condenser is connected to expansion valve, expansion valve is connected to evaporator.

[0039] Furthermore, the working fluid of the superstructured Carnot battery energy storage system is water. The working fluid is subjected to different cycles of reheating and compression through the discrete flow divider I, and becomes a high temperature and high pressure state. It is then passed to the heat exchanger for multiple heat exchanges, so that the heat storage tank can fully store the phase change heat of the working fluid. The heat storage tank is connected to the bottom circulating power generation system and acts as the heat source of the bottom circulating power generation system.

[0040] The cooling medium of the condenser in the superstructured Carnot battery energy storage system is circulating cooling water, and the heat storage medium in the heat storage tank is an inorganic salt-based high-temperature resistant heat storage material.

[0041] Further, in step S2, the superstructured Carnot battery power generation system formed by the combination includes: a discrete splitter III, a precooler, a pre-compressor II, a continuous splitter II, a main cooler, a main compressor II, a split compressor II, a continuous splitter III, a heat exchanger III, a discrete splitter IV, an expander generator I, a low-temperature regenerator, a continuous splitter IV, a heat exchanger IV, a discrete splitter V, an expander generator II, a high-temperature regenerator, a discrete splitter VI, an expander generator III, a heat exchanger V, and an expander generator IV. The discrete splitter III is connected to the precooler; the precooler is connected to the pre-compressor II; the pre-compressor II is connected to the continuous splitter II; the discrete splitter III is connected to the continuous splitter II; the continuous splitter II is connected to the main cooler; the main cooler is connected to the main compressor II; the main compressor II is connected to the continuous splitter III; the continuous splitter II is connected to the split compressor II; the split compressor II is connected to the heat exchanger III; and the continuous splitter III is connected to... Heat exchanger III is connected to discrete flow divider IV, discrete flow divider IV is connected to expander generator I, expander generator I is connected to low-temperature regenerator, continuous flow divider III is connected to low-temperature regenerator, low-temperature regenerator is connected to discrete flow divider III, low-temperature regenerator is connected to continuous flow divider IV, discrete flow divider IV is connected to continuous flow divider IV, continuous flow divider IV is connected to heat exchanger IV, heat exchanger IV is connected to discrete flow divider V, discrete flow divider V is connected to expander generator I. Machine II is connected; Expansion generator II is connected to the high-temperature regenerator; Continuous splitter IV is connected to the high-temperature regenerator; High-temperature regenerator is connected to the low-temperature regenerator; High-temperature regenerator is connected to discrete splitter VI; Discrete splitter V is connected to discrete splitter VI; Discrete splitter VI is connected to expansion generator III; Expansion generator III is connected to the low-temperature regenerator; Discrete splitter VI is connected to heat exchanger V; Heat exchanger V is connected to expansion generator IV; Expansion generator is connected to the high-temperature regenerator.

[0042] Furthermore, the working fluid of the superstructured Carnot battery power generation system is supercritical CO2. At the cold end, the working fluid is cooled and compressed multiple times through the discrete flow divider III, becoming a low-temperature and high-pressure state, and finally converges to the hot end for power circulation. At the hot end, the working fluid is heated, expanded to generate electricity, and regenerated multiple times through the discrete and continuous flow dividers III, IV, V, and VI.

[0043] The cooling medium of the cooler in the superstructured Carnot battery power generation system is circulating cooling water.

[0044] Compared with the prior art, the present invention has the following advantages:

[0045] 1. The construction method of the superstructure Carnot battery energy storage and power generation system provided by the present invention, the construction of the system and the optimization of the system can obtain the optimal joint system cyclic operation parameters.

[0046] 2. The construction method of the superstructured Carnot battery energy storage and power generation system provided by the present invention has a high degree of flexibility and practicality in the construction of the combined system. The top-cycle energy storage system can interact and depend on the bottom-cycle power generation system, providing ideas for the construction of combined systems under different conditions.

[0047] 3. The construction method of the superstructured Carnot battery energy storage and power generation system provided by the present invention benefits from the Carnot battery energy storage system at the top, and the supercritical CO2 power cycle system at the bottom has great flexibility in terms of time operation.

[0048] 4. The construction method of the superstructure Carnot battery energy storage power generation system provided by the present invention has higher performance and is more advanced compared with the traditional Carnot battery energy storage power generation system.

[0049] Based on the above reasons, this invention can be widely promoted in the fields of energy storage, waste heat recovery and utilization. Attached Figure Description

[0050] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0051] Figure 1 This is a flowchart of the construction method of the present invention.

[0052] Figure 2 The diagram shows 10 energy storage configurations and a superstructure Carnot battery energy storage system of the present invention, wherein (a) is a single-cycle regeneration, single-compression, single-heat exchange configuration; (b) is a single-cycle regeneration, double-compression, single-heat exchange configuration; (c) is a double-cycle regeneration, single-compression, single-heat exchange configuration; (d) is a double-cycle regeneration, double-compression, single-heat exchange configuration; (e) is a double-cycle regeneration, triple-compression, single-heat exchange configuration; (f) is a single-cycle regeneration, single-compression, double-heat exchange configuration; (g) is a single-cycle regeneration, double-compression, double-heat exchange configuration; (h) is a double-cycle regeneration, single-compression, double-heat exchange configuration; (i) is a double-cycle regeneration, double-compression, double-heat exchange configuration; (j) is a double-cycle regeneration, triple-compression, double-heat exchange configuration; and (k) is a schematic diagram of a superstructure Carnot battery energy storage system.

[0053] Figure 3The diagram shows the cold end of the five cold end configurations and the superstructure Carnot battery energy storage system of the present invention, wherein (a) is the basic cooling configuration, (b) is the shunt compression cooling configuration, (c) is the pre-cooled shunt compression configuration (pre-cooling configuration), (d) is the intermediate cooling configuration, and (e) is the intermediate cooling shunt compression cooling configuration.

[0054] Figure 4 The diagram shows the hot-end configurations of the 12 hot-end configurations and the hot-end configuration of the superstructure Carnot battery energy storage system of the present invention, wherein (a) is a configuration of two heating and one regeneration and one expansion, (b) is a configuration of two heating and two regeneration and one expansion, (c) is a configuration of two heating and one regeneration and two expansion, (d) is a configuration of two heating and two regeneration and two expansion, (e) is a configuration of two heating and one regeneration and one expansion, (f) is a configuration of two heating and two regeneration and two expansion, (g) is a configuration of three heating and two regeneration and one expansion, (h) is a configuration of three heating and two regeneration and two expansion, (i) is a configuration of two heating and one regeneration and two expansion, (j) is a configuration of two heating and two regeneration and three expansion, (k) is a configuration of three heating and two regeneration and two expansion, and (l) is a configuration of three heating and two regeneration and three expansion.

[0055] Figure 5 This is a schematic diagram of a superstructured Carnot battery energy storage and power generation system according to Embodiment 2 of the present invention.

[0056] Figure 6 This is a schematic diagram of a superstructured Carnot battery energy storage and power generation system according to Embodiment 3 of the present invention.

[0057] In the diagram: 1. Evaporator; 2. Discrete splitter I; 3. Pre-regenerator; 4. Pre-compressor I; 5. Continuous splitter I; 6. Main regenerator; 7. Main compressor I; 8. Split compressor I; 9. Heat exchanger I; 10. Heat storage tank I; 11. Discrete splitter II; 12. Heat exchanger II; 13. Heat storage tank II; 14. Condenser; 15. Expansion valve; 16. Discrete splitter III; 17. Pre-cooler; 18. Pre-compressor II; 19. Continuous splitter II; 20. Main cooler; 21. Main compressor II; 22. Split compressor II; 23. Continuous splitter III; 24. Heat exchanger III; 25. Discrete splitter IV; 26. Expansion generator I; 27. Low-temperature regenerator; 28. Continuous splitter IV; 29. ​​Heat exchanger IV; 30. Discrete splitter V; 31. Expansion generator II; 32. High-temperature regenerator; 33. Discrete splitter VI; 34. Expansion generator III; 35. Heat exchanger V; 36. Expansion generator IV. Detailed Implementation

[0058] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0059] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0060] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0061] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0062] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms 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, and therefore should not be construed as a limitation on the scope of protection of this invention. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0063] For ease of description, spatial relative terms such as "above," "over," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation besides the orientation of the device as described in the figures. For example, if the device in the figures is inverted, a device described as "above" or "above" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0064] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0065] Example 1

[0066] This invention provides a method for constructing a superstructured Carnot battery energy storage and power generation system. Based on traditional Carnot battery energy storage and power generation systems, it lists various energy storage system configurations and various power generation system configurations, combining them to form a superstructured Carnot battery energy storage and power generation system. This system is superior to traditional Carnot battery energy storage and power generation systems, with improved system performance under various boundary conditions.

[0067] like Figure 1 As shown, the present invention provides a method for constructing a superstructured Carnot battery energy storage and power generation system, the specific steps of which include the following:

[0068] Step 1: Design a top-cycle energy storage system and list various energy storage configurations. During the reheating and compression of the working fluid, multiple reheating processes can effectively improve system performance and increase the stored heat capacity. The temperature rise during multiple compression processes is reduced, and multiple compressions also lead to increased system power consumption; therefore, compressions of four or more times are not considered. From this, we can design: 5 single-cycle heat exchange structures and 5 double-cycle heat exchange structures. The five single-cycle heat exchange structures are: single-cycle regeneration single-compression single-cycle heat exchange configuration, single-cycle regeneration double-compression single-cycle heat exchange configuration, double-cycle regeneration single-compression single-cycle heat exchange configuration, double-cycle regeneration double-compression single-cycle heat exchange configuration, and double-cycle regeneration triple-compression single-cycle heat exchange configuration; the five double-cycle heat exchange structures are: single-cycle regeneration single-compression double-cycle heat exchange configuration, single-cycle regeneration double-compression double-cycle heat exchange configuration, double-cycle regeneration single-compression double-cycle heat exchange configuration, double-cycle regeneration double-compression double-cycle heat exchange configuration, and double-cycle regeneration triple-compression double-cycle heat exchange configuration; all of these are combined to form the most complete superstructure Carnot battery energy storage system. The ten energy storage configurations and the superstructure Carnot battery energy storage system are as follows: Figure 2 As shown. It should be noted that the 10 energy storage configurations can be combined to obtain various superstructure Carnot battery energy storage systems, and all combinations can form the most complete superstructure Carnot battery energy storage system.

[0069] Step 2: Design the bottom-cycle power generation system, using supercritical CO2 as the working fluid. First, design the cold end: When cooling CO2, secondary cooling can effectively reduce compressor energy consumption because it further lowers the compressor inlet temperature. However, as CO2 density increases and compressibility decreases near its critical point, the temperature rise during compression decreases. Therefore, for the superstructure's cooling end, three or more secondary cooling designs will not be considered. By changing the CO2 split ratio and compression ratio, five cold end structures can be designed: basic cooling configuration, split-compression cooling configuration, pre-cooling cooling configuration, intermediate cooling configuration, and intermediate cooling split-compression cooling configuration. These are then combined to form the most complete superstructure Carnot battery power generation system's cold end structure. The five cold end configurations are as follows: Figure 3 As shown. It should be noted that the five cold-end configurations can be combined to obtain various cold-end structures, and all combinations can form the most complete cold-end structure of the superstructure Carnot battery power generation system.

[0070] Step 3: Hot-end Design: In the hot-end section of the superstructured Carnot battery power generation system, if only one heat exchanger (CH) is configured in the system during CO2 heat exchange, the heat stored in the storage tank cannot be fully utilized. Therefore, this invention proposes a solution: introducing three heat exchangers into the system. This design enables the system to achieve two different heat exchange modes: secondary heat exchange and tertiary heat exchange. Furthermore, the system includes a low-temperature regenerator and a high-temperature regenerator, allowing for single-stage and double-stage regeneration. By adjusting the split ratio at the outlet of each main heater, the hot end can be configured for single-stage, double-stage, and tertiary expansion. This flexible system design helps improve thermal efficiency and energy utilization. By changing the CO2 split ratio and compression ratio, four single-split structures and eight double-split structures can be designed. Four single-split structures are included: a secondary heating, single-regeneration, and single-expansion configuration; a secondary heating, secondary regeneration, and single-expansion configuration; a secondary heating, single-regeneration, and secondary-expansion configuration; and a secondary heating, secondary regeneration, and secondary-expansion configuration. Eight dual-split structures are included: a secondary heating, single-regeneration, and single-expansion configuration; a secondary heating, secondary regeneration, and secondary-expansion configuration; a tertiary heating, secondary regeneration, and single-expansion configuration; a tertiary heating, secondary regeneration, and secondary-expansion configuration; a secondary heating, secondary regeneration, and tertiary-expansion configuration; and a tertiary heating, secondary regeneration, and tertiary-expansion configuration. All of these are then combined to form the most complete superstructure Carnot battery power generation system's hot-end structure. Twelve hot-end configurations are listed below. Figure 4 As shown. It should be noted that the 12 hot-end configurations can be combined to obtain a variety of hot-end structures, and all combinations can form the most complete hot-end structure of the superstructure Carnot battery power generation system.

[0071] Step 4: Based on the cold end structure and hot end structure designed in Step 2 and Step 3, merge them all to obtain the superstructure Carnot battery power generation system.

[0072] Step 5: Based on steps 1 and 4, combining the superstructure Carnot battery energy storage system with the superstructure Carnot battery power generation system can realize 600 different configurations of Carnot battery energy storage and power generation systems, resulting in a single superstructure Carnot battery energy storage and power generation system. The superstructure Carnot battery energy storage and power generation system is as follows: Figure 5 As shown.

[0073] Step 6: Based on Step 1, determine the boundary parameters of the top-circulation superstructure Carnot battery energy storage system, including determining the ambient temperature, ambient pressure, heat source temperature, main heat exchanger temperature difference, compressor isentropic efficiency, heat storage tank temperature, storage time, etc.

[0074] Step 7: Based on Step 6, calculate the performance parameters of the top-cycle Carnot battery energy storage system. This includes:

[0075] Heat pump energy efficiency ratio: COP = Q out ÷W comp ;

[0076] Total power consumption of the compressor: ∑W comp =W4 + W7 + W8;

[0077] Pre-compressor I power consumption:

[0078] Main compressor I power consumption:

[0079] Power consumption of split compressor I:

[0080] Thermal energy storage tanks:

[0081] In the formula, For the quality of circulating working fluid water; h 4,out The specific enthalpy value at the outlet of pre-compressor I; h 4,in The specific enthalpy value at the inlet of pre-compressor I; h 7,out Main compressor I outlet specific enthalpy value; h 7,in Main compressor I inlet specific enthalpy value; h 8,out The specific enthalpy value at the outlet of the split compressor I; h 8,in c is the inlet specific enthalpy of the split compressor I; p T is the specific heat capacity at constant pressure. in T is the inlet temperature of the thermal storage tank. out This refers to the outlet temperature of the thermal storage tank.

[0082] Step 8: Based on Step 4, determine the boundary parameters of the bottom-circulation superstructure Carnot battery power generation system, including: determining the ambient temperature; determining the ambient pressure; determining the CO2 temperature; determining the thermal storage tank temperature; determining the compressor isentropic efficiency; determining the expansion generator isentropic efficiency; determining the cooling water inlet temperature; and determining the cooling water outlet temperature.

[0083] Step 9: Based on Step 4, determine the optimization variables and their value ranges for the bottom-circulation supercritical CO2 power cycle system, including: CO2 mass flow rate; pre-compressor pressure ratio; maximum pressure; minimum pressure; expansion generator inlet temperature; cooler inlet temperature; continuous splitter split ratio; discrete splitter split ratio; main heat exchanger temperature difference; regenerator temperature difference; cooler temperature difference.

[0084] Step 10: Based on Steps 8 and 9, calculate the performance parameters of the bottom-circulation superstructured supercritical CO2 power cycle system. The energy models for each component are as follows:

[0085] Net power generation efficiency:

[0086] Total power consumption of the compressor: ∑W comp =W 18 +W 21 +W 22 ;

[0087] Pre-compressor II power consumption:

[0088] Main compressor II power consumption:

[0089] Power consumption of split compressor II:

[0090] Total expansion work: ∑W Tur =W 26 +W 31 +W 34 +W 36 ;

[0091] Expansion work of expander generator I:

[0092] Expansion work of expander generator II:

[0093] Expansion work of expander generator III:

[0094] Expansion work of expander generator IV:

[0095] System net output power: W net =∑W Tur -W comp ;

[0096] System thermal efficiency: η th =W net ÷Q out ;

[0097] Heat released by the heat storage tank:

[0098] Heat recovery rate: η re =Q tot ÷Q out ;

[0099] In the formula, h represents the mass of carbon dioxide in the circulating working fluid. 18,out The specific enthalpy value at the outlet of pre-compressor II; h 18,in The specific enthalpy value at the inlet of pre-compressor II; h 21,out Main compressor II outlet specific enthalpy value; h 21,in Main compressor II inlet specific enthalpy value; h 22,out The specific enthalpy value at the outlet of the split compressor II; h 22,inThe specific enthalpy value of the inlet II of the split compressor; h 26,in The specific enthalpy at the inlet of expander generator I; h 26,out The specific enthalpy of the outlet of the expander generator I; h 31,in The specific enthalpy at the inlet of the expander generator II; h 31,out The specific enthalpy of the expander generator II outlet; h 34,in The specific enthalpy at the inlet of the expander generator III; h 34,out The specific enthalpy of the expansion generator III outlet; h 36,in The specific enthalpy at the inlet of the expander generator IV; h 36,out The specific enthalpy of the expansion generator IV outlet; h 24,out The specific enthalpy at the outlet of heat exchanger III; h 24,in The specific enthalpy at the inlet of heat exchanger III; h 29,out The specific enthalpy at the outlet of heat exchanger IV; h 29,in The specific enthalpy at the inlet of heat exchanger IV; h 35,out h is the specific enthalpy at the outlet of heat exchanger V. 35,in This is the specific enthalpy value at the V inlet of the heat exchanger.

[0100] Step 11: Investigate the influence of key parameters on the optimal structure of the superstructured supercritical CO2 power cycle system:

[0101] (1) Temperature of the heat storage tank: Changes in the heat source temperature directly affect the number of heating and expansion cycles at the hot end. It was found that when the cold end is configured with an intermediate cooling split-flow compression structure and the hot end with a dual-split-flow structure, the higher the heat source temperature, the higher the system's net output power (W). net System thermal efficiency η th Net power generation efficiency η net Heat recovery rate η re All of these temperatures have risen significantly, therefore the higher the temperature of the thermal storage tank, the better.

[0102] (2) Cooling method: The choice between wet cooling and dry cooling directly affects the system structure, particularly the split-flow compression structure at the cold end, and thus the total compressor energy consumption ∑W. comp System net output power W net System thermal efficiency η th It has a significant impact. The net output power (W) of the system under humid and cold conditions. net Heat recovery rate η re Both are superior to dry cooling conditions, and the total compressor energy consumption ∑W comp Below dry and cold conditions.

[0103] (3) Equipment parameters: The pressure drop of the heat exchanger, and the isentropic efficiency of the compressor and expansion generator, also affect the configuration of the superstructured supercritical CO2 power cycle system. After determining the temperature of the heat storage tank (heat source temperature) and wet cooling, changing the percentage of pressure drop in the heat exchanger revealed that as the percentage of pressure drop increased, the system's net power output W... netSystem thermal efficiency η th When the pressure drop percentage exceeds 1%, the structure of the superstructured supercritical CO2 power cycle system will change.

[0104] Step 12: Multi-objective optimization of the system. Improving the thermal performance of the system will increase the complexity of the system, leading to an increase in economic costs. The economic efficiency and thermal performance are balanced by multi-objective optimization. This is achieved by optimizing the system structure as an optimization variable. (1) Top-circulation superstructure Carnot battery energy storage system, the process is as follows: 1. Determine the objective function. 2. Select decision variables. 3. Select the optimization algorithm. 4. Apply the decision method. (2) Bottom-circulation superstructure Carnot battery power generation system, the MIDACO algorithm is used for multi-objective optimization, the process steps are as follows: 1. Initialization stage 2. Variable generation. 3. Calculate the objective function value. 4. Iterative judgment.

[0105] Step 13: End.

[0106] Example 2

[0107] like Figure 5 The diagram shows a superstructured Carnot battery energy storage and power generation system obtained based on the construction method of the present invention, including a superstructured Carnot battery energy storage system and a superstructured Carnot battery power generation system.

[0108] The energy storage configuration includes at least an evaporator 1, a discrete distributor I2, a continuous distributor I5, a main regenerator 6, a main compressor I7, a heat exchanger I9, a heat storage tank I10, a discrete distributor II11, a condenser 14, and an expansion valve 15. The evaporator 1 is connected to the discrete distributor I2, the discrete distributor I2 is connected to the continuous distributor I5, the continuous distributor I5 is connected to the main regenerator 6, the main regenerator 6 is connected to the main compressor I7, the main compressor I7 is connected to the heat exchanger I9, the heat exchanger I9 is ​​connected to the heat storage tank I10, the heat exchanger I9 is ​​connected to the discrete distributor II11, the discrete distributor II11 is connected to the condenser 14, the condenser 14 is connected to the expansion valve 15, and the expansion valve 15 is connected to the evaporator 1.

[0109] The discrete splitter I2 can also be connected to the regenerator 3, and the discrete splitter I2 is connected to the continuous splitter I5 through the regenerator 3, and / or the discrete splitter I2 is directly connected to the continuous splitter I5. The regenerator 3 can also be connected to the pre-compressor I4, and the pre-compressor I4 is connected to the continuous splitter I5. The continuous splitter I5 can also be connected to the split compressor I8, and the split compressor I8 is connected to the heat exchanger I9. The discrete splitter II11 can also be connected to the heat exchanger II12, and the heat exchanger II12 is connected to the heat storage tank II13, and the heat exchanger II12 is connected to the condenser 14.

[0110] The combined superstructure Carnot battery energy storage system includes: evaporator 1, discrete splitter I2, preheater 3, pre-compressor I4, continuous splitter I5, main regenerator 6, main compressor I7, split compressor I8, heat exchanger I9, heat storage tank I10, discrete splitter II11, heat exchanger II12, heat storage tank II13, condenser 14, and expansion valve 15. Evaporator 1 is connected to discrete splitter I2, discrete splitter I2 is connected to regenerator 3, preheater 3 is connected to pre-compressor I4, pre-compressor I4 is connected to continuous splitter I5, and discrete splitter I2 is connected to continuous splitter I5. The continuous flow divider I5 is connected to the main regenerator 6, the main regenerator 6 is connected to the main compressor I7, the continuous flow divider I5 is connected to the flow divider compressor I8, the main compressor I7 is connected to the heat exchanger I9, the flow divider compressor I8 is connected to the heat exchanger I9, the heat exchanger I9 is ​​connected to the heat storage tank I10, the heat exchanger I9 is ​​connected to the discrete flow divider II11, the discrete flow divider II11 is connected to the heat exchanger II12, the heat exchanger II12 is connected to the heat storage tank II13, the heat exchanger II12 is connected to the condenser 14, the discrete flow divider II11 is connected to the condenser 14, the condenser 14 is connected to the expansion valve 15, and the expansion valve 15 is connected to the evaporator 1.

[0111] The cold-end configuration includes at least a discrete splitter III 16, a continuous splitter II 19, a main cooler 20, and a main compressor II 21. Discrete splitter III 16 is connected to continuous splitter II 19, continuous splitter II 19 is connected to main cooler 20, and main cooler 20 is connected to main compressor II 21. Discrete splitter III 16 can also be connected to continuous splitter II 19 via precooler 17. Precooler 17 can also be connected to continuous splitter II 19 via pre-compressor II 18. Continuous splitter II 19 can also be connected to splitter compressor II 22.

[0112] The hot-end configuration includes at least a continuous flow divider III 23, a heat exchanger III 24, a discrete flow divider IV 25, a low-temperature regenerator 27, and a continuous flow divider IV 28. The main compressor II 21 is connected to the continuous flow divider III 23, the flow divider compressor II 22 is connected to the heat exchanger III 24, the continuous flow divider III 23 is connected to the heat exchanger III 24, the heat exchanger III 24 is connected to the discrete flow divider IV 25, the continuous flow divider III 23 is connected to the low-temperature regenerator 27, the discrete flow divider IV 25 is connected to the continuous flow divider IV 28, and the low-temperature regenerator 27 is connected to the continuous flow divider IV 28.

[0113] The combined superstructure Carnot battery power generation system includes: discrete splitter III 16, precooler 17, pre-compressor II 18, continuous splitter II 19, main cooler 20, main compressor II 21, split compressor II 22, continuous splitter III 23, heat exchanger III 24, discrete splitter IV 25, expander generator I 26, low-temperature regenerator 27, continuous splitter IV 28, heat exchanger IV 29, discrete splitter V 30, expander generator II 31, high-temperature regenerator 32, discrete splitter VI 33, expander generator III 34, heat exchanger V 35, and expander... Motor IV 36, discrete splitter III 16 is connected to precooler 17; precooler 17 is connected to pre-compressor II 18, pre-compressor II 18 is connected to continuous splitter II 19, discrete splitter III 16 is connected to continuous splitter II 19, continuous splitter II 19 is connected to main cooler 20, main cooler 20 is connected to main compressor II 21, main compressor II 21 is connected to continuous splitter III 23, continuous splitter II 19 is connected to split compressor II 22, split compressor II 22 is connected to heat exchanger III 24, continuous splitter III 23 is connected to heat exchanger III 24. Heat exchanger III24 is connected to discrete flow divider IV25, discrete flow divider IV25 is connected to expander generator I26, expander generator I26 is connected to low-temperature regenerator 27, continuous flow divider III23 is connected to low-temperature regenerator 27, low-temperature regenerator 27 is connected to discrete flow divider III16, low-temperature regenerator 27 is connected to continuous flow divider IV28, discrete flow divider IV25 is connected to continuous flow divider IV28, continuous flow divider IV28 is connected to heat exchanger IV29, heat exchanger IV29 is connected to discrete flow divider V30, discrete flow divider V30 is connected to expander generator II31. The expansion generator II 31 is connected to the high-temperature regenerator 32, the continuous flow divider IV 28 is connected to the high-temperature regenerator 32, the high-temperature regenerator 32 is connected to the low-temperature regenerator 27, the high-temperature regenerator 32 is connected to the discrete flow divider VI 33, the discrete flow divider V 30 is connected to the discrete flow divider VI 33, the discrete flow divider VI 33 is connected to the expansion generator III 34, the expansion generator III 34 is connected to the low-temperature regenerator 27, the discrete flow divider VI 33 is connected to the heat exchanger V 35, the heat exchanger V 35 is connected to the expansion generator IV 36, and the expansion generator 35 is connected to the high-temperature regenerator 32.

[0114] The working fluid of the superstructured Carnot battery energy storage system is water. The working fluid is subjected to different cycles of reheating and compression through the discrete flow divider I2, and becomes a high temperature and high pressure state. It is then passed to the heat exchanger for multiple heat exchanges, so that the heat storage tank can fully store the phase change heat of the working fluid. The heat storage tank is connected to the bottom circulation power generation system and acts as the heat source of the bottom circulation power generation system.

[0115] The working fluid in the superstructured Carnot battery power generation system is supercritical CO2. At the cold end, the working fluid is cooled and compressed multiple times through the discrete flow divider Ⅲ16, becoming a low-temperature and high-pressure state, and finally converges to the hot end for power circulation. At the hot end, the working fluid is heated, expanded to generate electricity, and regenerated multiple times through the discrete and continuous flow dividers Ⅲ23, Ⅳ25, Ⅳ28, Ⅴ30, and Ⅵ33.

[0116] The cooling medium for the condenser of the superstructure Carnot battery energy storage system and the cooler of the superstructure Carnot battery power generation system is circulating cooling water, while the heat storage medium in the heat storage tank is an inorganic salt-based high-temperature resistant heat storage material.

[0117] Example 3

[0118] The present invention provides a method for constructing a superstructured Carnot battery energy storage and power generation system, which is applied to industrial waste heat applications. The method specifically includes the following steps:

[0119] Step 1: Design a top-cycle energy storage system and list various energy storage configurations. During the reheating and compression of the working fluid, multiple reheating cycles can effectively improve system performance and increase the stored heat capacity. The temperature rise during multiple compressions is reduced, and multiple compressions also increase system power consumption; therefore, compressions of four or more cycles are not considered. From this, we can design: 5 single-cycle heat exchange structures and 5 double-cycle heat exchange structures. The 5 single-cycle heat exchange structures are: single-cycle reheating single-compression single-cycle heat exchange configuration, single-cycle reheating double-compression single-cycle heat exchange configuration, double-cycle reheating single-compression single-cycle heat exchange configuration, double-cycle reheating double-compression single-cycle heat exchange configuration, and double-cycle reheating triple-compression double-cycle heat exchange configuration. The 5 double-cycle heat exchange structures are: single-cycle reheating single-compression double-cycle heat exchange configuration, single-cycle reheating double-compression double-cycle heat exchange configuration, double-cycle reheating single-compression double-cycle heat exchange configuration, double-cycle reheating double-compression double-cycle heat exchange configuration, and double-cycle reheating triple-compression double-cycle heat exchange configuration. All components are then combined to form a superstructure Carnot battery energy storage system. Because industrial waste heat is characterized by high and stable heat source temperatures, the superstructure Carnot battery energy storage system employs a secondary regeneration, tertiary compression, and secondary heat exchange configuration to fully utilize and store the heat from industrial waste heat.

[0120] Step 2: Design the bottom-cycle power generation system, using supercritical CO2 as the working fluid. First, design the cold end: When cooling CO2, secondary cooling can effectively reduce compressor energy consumption because it further lowers the compressor inlet temperature. However, as CO2 density increases and compressibility decreases near its critical point, the temperature rise during compression decreases. Therefore, for the superstructure's cooling end, three or more secondary cooling designs will not be considered. By changing the CO2 split ratio and compression ratio, five cold end structures can be designed: basic cooling configuration, split-compression cooling configuration, pre-cooling cooling configuration, intermediate cooling configuration, and intermediate cooling split-compression cooling configuration. These are then combined to form the cold end structure of the superstructure Carnot battery power generation system. Due to the high heat output and stable heat source characteristics of industrial waste heat, the intermediate cooling split-compression cooling configuration is chosen for the cold end of the superstructure Carnot battery power generation system. This improves the cold end's performance parameters and reduces power consumption.

[0121] Step 3: Hot-end Design: In the hot-end section of the superstructured Carnot battery power generation system, if only one heat exchanger (CH) is configured in the system during CO2 heat exchange, the heat stored in the storage tank cannot be fully utilized. Therefore, this invention proposes a solution: introducing three heat exchangers into the system. This design enables the system to achieve two different heat exchange modes: secondary heat exchange and tertiary heat exchange. Furthermore, the system includes a low-temperature regenerator and a high-temperature regenerator, allowing for single-stage and double-stage regeneration. By adjusting the split ratio at the outlet of each main heater, the hot end can be configured for single-stage, double-stage, and tertiary expansion. This flexible system design helps improve thermal efficiency and energy utilization. By changing the CO2 split ratio and compression ratio, four single-split structures and eight double-split structures can be designed. Four single-split structures are included: a secondary heating, single-regeneration, and single-expansion configuration; a secondary heating, secondary regeneration, and single-expansion configuration; a secondary heating, single-regeneration, and secondary-expansion configuration; and a secondary heating, secondary regeneration, and secondary-expansion configuration. Eight dual-split structures are included: a secondary heating, single-regeneration, and single-expansion configuration; a secondary heating, secondary regeneration, and secondary-expansion configuration; a tertiary heating, secondary regeneration, and single-expansion configuration; a tertiary heating, secondary regeneration, and secondary-expansion configuration; a secondary heating, secondary regeneration, and tertiary-expansion configuration; and a tertiary heating, secondary regeneration, and tertiary-expansion configuration. All these are then combined to form the hot-end structure of the superstructure Carnot battery power generation system. Due to the high heat capacity and stable heat source characteristics of industrial waste heat, the hot-end of the superstructure Carnot battery power generation system selects a tertiary heating, secondary regeneration, and tertiary-expansion configuration. This allows for full utilization of the heat in the storage tank, resulting in higher system efficiency.

[0122] Step 4: Based on the cold end structure and hot end structure designed in Step 2 and Step 3, combine them to obtain the superstructure Carnot battery power generation system.

[0123] Step 5: Based on steps 1 and 4, combine the superstructure Carnot battery energy storage system with the superstructure Carnot battery power generation system to obtain a superstructure Carnot battery energy storage and power generation system. The superstructure Carnot battery energy storage and power generation system is as follows: Figure 2 As shown.

[0124] Step 6: Based on Step 1, determine the boundary parameters of the top-cycle superstructure Carnot battery energy storage system, including:

[0125] The ambient temperature is set at 55℃, the ambient pressure at 101.325 kPa, the industrial waste heat temperature at 200-600℃, the heat exchanger temperature difference at 5℃, the compressor isentropic efficiency at 85%, the heat storage tank temperature at 700℃, and the storage time at 10 hours, etc.

[0126] Step 7: Based on Step 6, calculate the performance parameters of the top-cycle Carnot battery energy storage system. This includes:

[0127] Heat pump energy efficiency ratio: COP = Q out ÷W comp ;

[0128] Total power consumption of compressor ∑W comp =W4 + W7 + W8;

[0129] Pre-compressor I power consumption:

[0130] Main compressor I power consumption:

[0131] Power consumption of split compressor I:

[0132] Thermal energy storage tanks:

[0133] In the formula, For the quality of circulating working fluid water; h 4,out The specific enthalpy value at the outlet of pre-compressor I; h 4,in The specific enthalpy value at the inlet of pre-compressor I; h 7,out Main compressor I outlet specific enthalpy value; h 7,in Main compressor I inlet specific enthalpy value; h 8,out The specific enthalpy value at the outlet of the split compressor I; h 8,in c is the inlet specific enthalpy of the split compressor I; p T is the specific heat capacity at constant pressure. in T is the inlet temperature of the thermal storage tank. out This refers to the outlet temperature of the thermal storage tank.

[0134] Step 8: Based on Step 4, determine the boundary parameters of the bottom-circulation superstructure Carnot battery power generation system, including:

[0135] Ambient temperature: 25℃; Ambient pressure: 101.325KPa; CO2 temperature: 25℃; Thermal storage tank temperature: 700℃; Compressor isentropic efficiency: 85%; Expander generator isentropic efficiency: 85%; Cooling water inlet temperature: 25℃; Cooling water outlet temperature: 40℃.

[0136] Step 9: Based on Step 4, determine the optimization variables and their value ranges for the bottom-circulation supercritical CO2 power cycle system, including:

[0137] CO2 mass flow rate: 100-1000 kg / s; Pre-compressor pressure ratio: [1, 3.33]; Maximum pressure: 20-25 MPa; Minimum pressure: 7.63-10 MPa; Expander inlet temperature: 100-680℃; Cooler inlet temperature: 32-75℃; Continuous splitter split ratio: [0, 1]; Discrete splitter split ratio: (0, 1); Main heat exchanger temperature difference: ≥20℃; Regenerator temperature difference: ≥5℃; Cooler temperature difference: ≥5℃.

[0138] Step 10: Based on Steps 8 and 9, calculate the performance parameters of the bottom-circulation superstructured supercritical CO2 power cycle system. The energy models for each component are as follows:

[0139] Net power generation efficiency:

[0140] Total power consumption of the compressor: ∑W comp =W 18 +W 21 +W 22 ;

[0141] Pre-compressor II power consumption:

[0142] Main compressor II power consumption:

[0143] Power consumption of split compressor II:

[0144] Total expansion work: ∑W Tur =W 26 +W 31 +W 36 ;

[0145] Expansion work of expander generator I:

[0146] Expansion work of expander generator II:

[0147] Expansion work of expander generator IV:

[0148] System net output power: W net =∑W Tur -W comp ;

[0149] System thermal efficiency: η th =W net ÷Q out ;

[0150] Heat released by the heat storage tank:

[0151] Heat recovery rate: η re =Q tot ÷Q out ;

[0152] In the formula, h represents the mass of carbon dioxide in the circulating working fluid. 18,out The specific enthalpy value at the outlet of pre-compressor II; h 18,in The specific enthalpy value at the inlet of pre-compressor II; h 21,out Main compressor II outlet specific enthalpy value; h 21,in Main compressor II inlet specific enthalpy value; h 22,out The specific enthalpy value at the outlet of the split compressor II; h 22,in The specific enthalpy value at the inlet of the split compressor II; h 26,in The specific enthalpy at the inlet of expander generator I; h 26,out The specific enthalpy of the outlet of the expander generator I; h 31,in The specific enthalpy at the inlet of the expander generator II; h 31,out The specific enthalpy of the expander generator II outlet; h 36,in The specific enthalpy at the inlet of the expander generator IV; h 36,out The specific enthalpy of the expansion generator IV outlet; h 24,out The specific enthalpy at the outlet of heat exchanger III; h 24,out The specific enthalpy at the inlet of heat exchanger III; h 29,out The specific enthalpy at the outlet of heat exchanger IV; h 29,in The specific enthalpy at the inlet of heat exchanger IV; h 35,out h is the specific enthalpy at the outlet of heat exchanger V. 35,in This is the specific enthalpy value at the V inlet of the heat exchanger.

[0153] Step 11: Investigate the influence of key parameters on the optimal structure of the superstructured supercritical CO2 power cycle system:

[0154] (1) Temperature of the heat storage tank: Changes in the heat source temperature directly affect the number of heating and expansion cycles at the hot end. It was found that when the cold end is configured with an intermediate cooling split-flow compression structure and the hot end with a dual-split-flow structure, the higher the heat source temperature, the higher the system's net output power (W). net System thermal efficiency η th Net power generation efficiency η net Heat recovery rate η re All these factors indicate a significant increase, therefore, the higher the temperature of the thermal storage tank, the better. Here, the temperature of the thermal storage tank is set to 700℃.

[0155] (2) Cooling method: The choice between wet cooling and dry cooling directly affects the system structure, particularly the split-flow compression structure at the cold end, and thus the total compressor energy consumption ∑W. comp System net output power W net System thermal efficiency η th It has a significant impact. The net output power (W) of the system under humid and cold conditions. net Heat recovery rate η re Both are superior to dry cooling conditions, and the total compressor energy consumption ∑W comp Below the dry cooling condition. Here, the cooling condition will be wet cooling.

[0156] (3) Equipment parameters: The pressure drop of the heat exchanger, and the isentropic efficiency of the compressor and expansion generator, also affect the configuration of the superstructured supercritical CO2 power cycle system. After determining the temperature of the heat storage tank (heat source temperature) and wet cooling, changing the percentage of pressure drop in the heat exchanger revealed that as the percentage of pressure drop increased, the system's net power output W... net System thermal efficiency η th When the pressure drop percentage exceeds 1%, the structure of the superstructured supercritical CO2 power cycle system will change.

[0157] Step 12: Multi-objective optimization of the system.

[0158] In step 12 of this invention, the existing non-dominated sorting multi-objective genetic algorithm NSGA-II based on the Pareto principle can be used, combined with the sorting decision method TOPSIS that approximates the ideal solution, to effectively solve the system parameter optimization problem and achieve synergistic improvement of thermodynamic and economic performance.

[0159] (1) The top-circulation superstructure Carnot battery energy storage system optimizes each different type of energy storage system. Here, we will use an industrial waste heat Carnot battery energy storage system as an example, and the steps are as follows:

[0160] 1. Selection of objective function:

[0161] Thermodynamic objective function: Select the overall system energy round-trip efficiency η p2pBecause of its thermodynamic cycle mode and energy storage conversion efficiency, it has attracted attention. High round-trip efficiency means that more charging energy is converted into discharging energy, that is: minF1=-η p2p Improve the efficiency of energy storage systems.

[0162] The economic objective function needs to encompass investment, operation and maintenance costs, and lifespan to determine the average cost per unit of stored energy (LCOS). That is: minF2 = LCOS.

[0163] 2. Determining decision variables:

[0164] Taking into account the changes in system performance evaluation indicators, the heat source temperature, energy storage temperature, ambient temperature, heat exchanger pinch point temperature difference, and evaporative superheat were selected as decision variables, with the following value ranges: heat source temperature: 500-700℃; ambient temperature: 20-30℃; heat exchanger pinch point temperature: 0-10℃; evaporative superheat: 4-8℃.

[0165] 3. Optimization algorithm selection:

[0166] The non-dominated sorting multi-objective genetic algorithm NSGA-II based on the Pareto principle is adopted. Since genetic algorithms follow the principle of natural selection and survival of the fittest, they are an effective metaheuristic method for solving complex optimization problems. NSGA-II improves upon the shortcomings of NSGA and features fast operation and good convergence. Its parameters are set as follows: population size 100, number of generations 150, crossover probability 0.8, mutation probability 0.1, and optimal front-end individual coefficient 0.62.

[0167] 4. Application of Decision-Making Methods: The TOPSIS (Topological Solution Approximation Method) is used to determine the optimal solution. The solutions on the Pareto front are normalized using Euclidean normalization.

[0168]

[0169] In the formula, f ij For the normalized solution; F ij This is the i-th solution for the j-th objective.

[0170] To avoid the impact of differences in the order of magnitude of different parameters.

[0171] Based on system characteristics, the round-trip energy efficiency is assigned a weight of 0.2 and the levelized energy storage cost is assigned a weight of 0.8. Let the ideal solution E be... + ={Max(f i1 ),Max(f i2 Non-ideal solution E - ={Min(f i1 ),Min(f i2 )}.

[0172] Calculate the Euclidean distance between each solution on the Pareto front and the ideal and non-ideal solutions:

[0173]

[0174] In the formula, D i + D is the Euclidean distance between each solution on the Pareto front and the ideal solution; i - E represents the Euclidean distance between each solution and the non-ideal solution on the Pareto front; + For the ideal solution; E - The solution is non-ideal; f ij The solution is normalized.

[0175] The optimal solution is the one that is closest to the ideal solution and furthest from the non-ideal solution.

[0176]

[0177] In the formula, R i The optimal solution is D. i + D is the Euclidean distance between each solution on the Pareto front and the ideal solution; i - Let be the Euclidean distance between each solution and the non-ideal solution on the Pareto front.

[0178] (2) For bottom-circulation superstructure Carnot battery power generation systems, improving the system's thermodynamic performance would increase its complexity, leading to higher economic costs. Therefore, a multi-objective optimization method is used to balance economic efficiency and thermodynamic performance. This objective is achieved by optimizing the system structure as an optimization variable.

[0179] This invention employs the MIDACO algorithm for multi-objective optimization, and the process steps are as follows:

[0180] 1. Initialization phase: Initialize the pheromone constant, pheromone factor, pheromone evaporation factor, heuristic function factor and time t required for ant colony algorithm calculation.

[0181] 2. MIDACO randomly generates A ants using a pseudo-random number generator, which is A sets of optimization variables.

[0182] 3. Matlab software transfers randomly generated Group A optimization variables to an Aspen Hysys spreadsheet via an ActiveX control. Thermodynamic calculations are then performed within Aspen Hysys to obtain the objective function values ​​corresponding to the optimization variables.

[0183] 4. The obtained objective function value is fed back to Matlab by Aspen Hysys, where the minimum objective function for the current number of calculations is determined.

[0184] 5. Determine if the computation has reached the termination condition. Here, the maximum number of computations and the maximum computation time are chosen as the termination conditions. If the termination condition is reached, output the minimum objective function and the corresponding optimization variable; if the termination condition is not reached, update the pheromone concentration and continue the iteration.

[0185] Step 13: End.

[0186] like Figure 6 The figure shown is a superstructured Carnot battery energy storage and power generation system obtained in Example 3, including an evaporator 1, a preheater 3, a pre-compressor I 4, a main regenerator 6, a main compressor I 7, a split compressor I 8, a heat exchanger I 9, a heat storage tank I 10, a heat exchanger II 12, a heat storage tank II 13, a condenser 14, an expansion valve 15, a precooler 17, a pre-compressor II 18, a main cooler 20, a main compressor II 21, a split compressor II 22, a heat exchanger III 24, an expansion generator I 26, a low-temperature regenerator 27, a heat exchanger IV 29, an expansion generator II 31, a high-temperature regenerator 32, and a heat exchanger V 35. The expansion generator Ⅳ36 is connected to the evaporator 1 and the regenerator 3. The pre-regenerator 3 is connected to the pre-compressor Ⅰ4. The pre-compressor Ⅰ4 is connected to the main regenerator 6. The main regenerator 6 is connected to the main compressor Ⅰ7. The main regenerator 6 is connected to the split compressor Ⅰ8. The main compressor Ⅰ7 is connected to the heat exchanger Ⅰ9. The split compressor Ⅰ8 is connected to the heat exchanger Ⅰ9. The heat exchanger Ⅰ9 is connected to the heat storage tank Ⅰ10. The heat exchanger Ⅰ9 is connected to the heat exchanger Ⅱ12. The heat exchanger Ⅱ12 is connected to the heat storage tank Ⅱ13. The heat exchanger Ⅱ12 is connected to the condenser 14. The condenser 14 is connected to the expansion valve 15. The expansion valve 15 is connected to the evaporator 1. Precooler 17 is connected to pre-compressor II 18, pre-compressor II 18 is connected to main cooler 20, main cooler 20 is connected to main compressor II 21, main compressor II 21 is connected to heat exchanger III 24, split compressor II 22 is connected to heat exchanger III 24, heat exchanger III 24 is connected to expansion generator I 26, expansion generator I 26 is connected to low-temperature regenerator 27, main compressor II 21 is connected to low-temperature regenerator 27, low-temperature regenerator 27 is connected to precooler 17, low-temperature regenerator 27 is connected to heat exchanger IV 29, heat exchanger IV 29 is connected to expansion generator II 31, expansion generator II 31 is connected to high-temperature regenerator 32, low-temperature regenerator 27 is connected to high-temperature regenerator 32, high-temperature regenerator 32 is connected to heat exchanger V 35, heat exchanger V 35 is connected to expansion generator IV 36, expansion generator 35 is connected to high-temperature regenerator 32.

[0187] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for constructing a superstructure Carnot cell energy storage power generation system, characterized in that, The method comprises the following steps: S1, designing a top cycle energy storage system to obtain a superstructure Carnot battery energy storage system; S2, designing a bottom cycle power generation system to obtain a superstructure Carnot battery power generation system; S3, combining the superstructure Carnot battery energy storage system obtained in step S1 with the superstructure Carnot battery power generation system obtained in step S2 to obtain a superstructure Carnot battery energy storage and power generation system; S4, determining the boundary parameters of the top cycle energy storage system according to step S1; S5, calculating the performance parameters of the top cycle energy storage system based on step S4; S6, determining the boundary parameters of the bottom cycle power generation system according to step S3; S7, determining the optimization variables and value range of the bottom cycle power generation system according to step S3; S8, calculating the performance parameters of the bottom cycle power generation system based on step S6 and step S7; S9, exploring the influence of key parameters on the superstructure Carnot battery energy storage and power generation system; S10, performing multi-objective optimization of the system; S11, ending; In the step S1, a plurality of energy storage configurations are constructed to form the superstructure Carnot battery energy storage system. In the step S2, the bottom cycle power generation system is designed to obtain the superstructure Carnot battery power generation system, which specifically comprises the following steps: S21, designing a cold end, constructing a plurality of cold end configurations, and combining to form a cold end structure of the superstructure Carnot battery power generation cycle; S22, designing a hot end, constructing a plurality of hot end configurations, including heating end configurations and heat recovery end configurations, and combining to form a hot end structure of the superstructure Carnot battery power generation cycle; S23, combining the cold end structure formed in step S21 with the hot end structure formed in step S22 to obtain the superstructure Carnot battery power generation system.

2. The method of constructing a superstructured Carnot cell energy storage generating system of claim 1, wherein, The energy storage configuration has 10 kinds, the cold end structure has 5 kinds, and the hot end structure has 12 kinds. The superstructure Carnot battery energy storage and power generation system formed by combining the 10 kinds of energy storage configurations, 5 kinds of cold end structures and 12 kinds of hot end structures realizes 600 kinds of Carnot battery energy storage and power generation cycles.

3. The method of constructing a superstructured Carnot cell energy storage generating system of claim 2, wherein, In the step S1, 10 kinds of energy storage configurations are constructed by means of multiple heat recovery, multiple compression and multiple heat exchange; the 10 kinds of energy storage configurations include 5 kinds of single heat exchange structures and 5 kinds of double heat exchange structures. The 5 kinds of single heat exchange structures include: single heat recovery, single compression and single heat exchange configuration, single heat recovery, double compression and single heat exchange configuration, double heat recovery, single compression and single heat exchange configuration, double heat recovery, double compression and single heat exchange configuration, double heat recovery, triple compression and single heat exchange configuration. The 5 kinds of double heat exchange structures include: single heat recovery, single compression and double heat exchange configuration, single heat recovery, double compression and double heat exchange configuration, double heat recovery, single compression and double heat exchange configuration, double heat recovery, double compression and double heat exchange configuration, double heat recovery, triple compression and double heat exchange configuration.

4. The method of constructing a superstructured Carnot cell energy storage generating system of claim 2, wherein, In the step S21, 5 kinds of structure cold end structures are constructed by means of intermediate cooling to reduce compression power consumption; the 5 kinds of structure cold end structures include: basic cooling configuration, split compression cooling configuration, pre-cooling cooling configuration, intermediate cooling configuration and intermediate cooling split compression cooling configuration.

5. The method of constructing a superstructured Carnot cell energy storage generating system of claim 4, wherein, In the step S22, the step S21 is performed for each of the plurality of heat exchangers. CO 2The 12 kinds of hot end structures are constructed by means of substream improvement, heat exchange matching, multiple heating and multiple heat recovery. The 12 kinds of hot end structures include 4 kinds of single substream structures and 8 kinds of double substream structures. The four single-flow structures include: a secondary heating single-heat recovery single-expansion configuration, a secondary heating double-heat recovery single-expansion configuration, a secondary heating single-heat recovery double-expansion configuration, and a secondary heating double-heat recovery double-expansion configuration. The eight double-flow structures include: a secondary heating single-heat recovery single-expansion configuration, a secondary heating double-heat recovery double-expansion configuration, a tertiary heating double-heat recovery single-expansion configuration, a tertiary heating double-heat recovery double-expansion configuration, a secondary heating single-heat recovery double-expansion configuration, a secondary heating double-heat recovery triple-expansion configuration, a tertiary heating double-heat recovery double-expansion configuration, and a tertiary heating double-heat recovery triple-expansion configuration.

6. The method of constructing a superstructured Carnot cell energy storage generating system of claim 3, wherein, In the step S1, the super-structure Carnot battery energy storage system formed by combination includes an evaporator (1), a discrete flow divider I (2), a pre-heat recovery device (3), a pre-compressor I (4), a continuous flow divider I (5), a main heat recovery device (6), a main compressor I (7), a flow divider compressor I (8), a heat exchanger I (9), a heat storage tank I (10), a discrete flow divider II (11), a heat exchanger II (12), a heat storage tank II (13), a condenser (14), and an expansion valve (15). The evaporator (1) is connected with the discrete flow divider I (2), the discrete flow divider I (2) is connected with the pre-heat recovery device (3), the pre-heat recovery device (3) is connected with the pre-compressor I (4), the pre-compressor I (4) is connected with the continuous flow divider I (5), the discrete flow divider I (2) is connected with the continuous flow divider I (5), the continuous flow divider I (5) is connected with the main heat recovery device (6), the main heat recovery device (6) is connected with the main compressor I (7), the continuous flow divider I (5) is connected with the flow divider compressor I (8), the main compressor I (7) is connected with the heat exchanger I (9), the flow divider compressor I (8) is connected with the heat exchanger I (9), the heat exchanger I (9) is connected with the heat storage tank I (10), the heat exchanger I (9) is connected with the discrete flow divider II (11), the discrete flow divider II (11) is connected with the heat exchanger II (12), the heat exchanger II (12) is connected with the heat storage tank II (13), the heat exchanger II (12) is connected with the condenser (14), the discrete flow divider II (11) is connected with the condenser (14), the condenser (14) is connected with the expansion valve (15), and the expansion valve (15) is connected with the evaporator (1).

7. The method of constructing a superstructured Carnot cell energy storage generating system of claim 6, wherein, The circulating working medium of the super-structure Carnot battery energy storage system is water. The working medium is subjected to different numbers of heat recoveries and compressions by the discrete action of the discrete flow divider I (2), becomes in a high-temperature and high-pressure state, is subjected to multiple heat exchanges in the heat exchanger, and makes the heat storage tank fully store the phase-change heat of the working medium. The heat storage tank is connected with the bottom circulating power generation system and serves as a heat source of the bottom circulating power generation system. The cooling medium of the condenser of the super-structure Carnot battery energy storage system is circulating cooling water, and the heat storage medium in the heat storage tank is an inorganic salt high-temperature resistant heat storage material.

8. The method of constructing a superstructured Carnot cell energy storage generating system of claim 5, wherein, The step S2, the superstructure formula Carnot battery generating system formed by combination includes: discrete shunt III (16), pre-cooler (17), pre-compressor II (18), continuous shunt II (19), main cooler (20), main compressor II (21), shunt compressor II (22), continuous shunt III (23), heat exchanger III (24), discrete shunt IV (25), expansion generator I (26), low temperature regenerator (27), continuous shunt IV (28), heat exchanger IV (29), discrete shunt V (30), expansion generator II (31), high temperature regenerator (32), discrete shunt VI (33), expansion generator III (34), heat exchanger V (35) and expansion generator IV (36), discrete shunt III (16) is connected with pre-cooler (17);Pre-cooler (17) is connected with pre-compressor II (18), pre-compressor II (18) is connected with continuous shunt II (19), discrete shunt III (16) is connected with continuous shunt II (19), continuous shunt II (19) is connected with main cooler (20), main cooler (20) is connected with main compressor II (21), main compressor II (21) is connected with continuous shunt III (23), continuous shunt II (19) is connected with shunt compressor II (22), shunt compressor II (22) is connected with heat exchanger III (24), continuous shunt III (23) is connected with heat exchanger III (24), heat exchanger III (24) is connected with discrete shunt IV (25), discrete shunt IV (25) is connected with expansion generator I (26), expansion generator I (26) is connected with low temperature regenerator (27), continuous shunt III (23) is connected with low temperature regenerator (27), low temperature regenerator (27) is connected with discrete shunt III (16), low temperature regenerator (27) is connected with continuous shunt IV (28), discrete shunt IV (25) is connected with continuous shunt IV (28), continuous shunt IV (28) is connected with heat exchanger IV (29), heat exchanger IV (29) is connected with discrete shunt V (30), discrete shunt V (30) is connected with expansion generator II (31), expansion generator II (31) is connected with high temperature regenerator (32), continuous shunt IV (28) is connected with high temperature regenerator (32), high temperature regenerator (32) is connected with low temperature regenerator (27), high temperature regenerator (32) is connected with discrete shunt VI (33), discrete shunt V (30) is connected with discrete shunt VI (33), discrete shunt VI (33) is connected with expansion generator III (34), expansion generator III (34) is connected with low temperature regenerator (27), discrete shunt VI (33) is connected with heat exchanger V (35), heat exchanger V (35) is connected with expansion generator IV (36), expansion generator (35) is connected with high temperature regenerator (32).

9. The method of constructing a superstructured Carnot cell energy storage generating system of claim 8, wherein, The circulating working medium of the superstructure Carnot battery power generation system is supercritical CO 2. At the cold end, the working medium realizes different times of cooling and compression through the discrete action of the discrete flow divider III (16), becomes a low-temperature high-pressure state, and finally converges to the hot end to perform a power cycle; at the hot end, the working medium realizes different times of heating, expansion power generation and heat recovery through the discrete and continuous flow action of the continuous flow divider III (23), the discrete flow divider IV (25), the continuous flow divider IV (28), the discrete flow divider V (30) and the discrete flow divider VI (33). The cooling medium of the cooler of the superstructure formula Carnot battery generating system is circulating cooling water.

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