An advanced analytical method and system for S-CO2 dual-turbine power generation systems

Abstract

This invention belongs to, but is not limited to, the field of analytical technology, and particularly relates to an advanced analysis method and system for an S-CO2 dual-turbine power generation system, comprising: S1, constructing an S-CO2 dual-turbine power cycle simulation model using the process simulation software Aspen HYSYS; S2, performing conventional analysis on the S-CO2 dual-turbine power generation system; S3, performing advanced analysis on the system, analyzing the potential for performance improvement of the system and its components; S4, exploring the effects of irreversible losses within the system; and S5, proposing a priority order for component improvements. This invention constructs an S-CO2 dual-turbine power generation system, uses Aspen HYSYS software as a tool to simulate system operation, calls the REFPROP database for property calculations, performs advanced analysis on the system, analyzes the potential for performance improvement, explores the effects of irreversible losses within the system, discusses the priority order for component improvements, and compares the results with those of conventional analysis.

Description

Technical Field

[0001] This invention belongs to, but is not limited to, the following categories: This research relates to the field of analysis technology, and in particular to an advanced S-CO2 dual-turbine power generation system. Analytical methods and systems. Background Technology

[0002] Supercritical carbon dioxide (S-CO2) Brayton cycle is an emerging clean power generation technology that combines advantages such as high operating efficiency, small equipment size, compact layout, and low maintenance difficulty. It has broad development prospects in the context of the current energy transition and also has great application potential in ships.

[0003] As early as the 1960s, Feher first proposed the S-CO2 power cycle, but due to insufficient manufacturing technology for key equipment at the time, it was difficult to meet engineering requirements and thus received little attention. It wasn't until subsequent technological advancements solved a series of problems, such as sealing the cycle under high temperature and pressure, that the S-CO2 power cycle technology regained importance. The academic and engineering communities invested considerable effort in it, and to date, S-CO2 power cycle technology has been extensively studied in many fields of thermal energy utilization, including nuclear energy, solar energy, and waste heat recovery.

[0004] In recent years, many researchers have used... Analytical methods were used to conduct a comprehensive study of S-CO2 power cycle technology. Sharma et al. completed energy analysis and... Analysis showed that the integrated system improved overall efficiency by 10% and net power by 25%. Abdelghafar et al. comprehensively compared the energy, performance, and efficiency of S-CO2 power cycles with different structures. economy, Economic performance, studies show that the three-cycle system The highest efficiency was achieved (27%), followed by the dual-cycle system (25%) and the single-cycle system (20%). Zhang et al. compared the thermodynamic and economic performance of ORC and S-CO2 power cycles, among which... Analysis results show that S-CO2 heat exchangers have fewer [unclear text - possibly related to heat exchange]. The heat loss is due to the absence of a phase change in the S-CO2 heat transfer process, resulting in good temperature matching. Furthermore, the study found that the recompression structure of the S-CO2 dynamic cycle can improve the system's thermal matching, thereby reducing the system's heat loss. The loss. Jiang et al. integrated the S-CO2 power cycle and the injection refrigeration cycle, compared with the single S-CO2 cycle. Efficiency can be improved by 2.65%, the main system The losses are concentrated in the regenerator.

[0005] Analysis methods have become mature and widely used tools for system performance analysis, capable of calculating device performance. loss, While it identifies areas for improvement in the cyclical process, it fails to quantify the potential for equipment improvement. (Advanced) The emergence of analytical methods has filled this gap, providing more detailed and in-depth analysis. Loss analysis quantifies the improvement potential of equipment and systems, simultaneously revealing the magnitude, location, and influencing factors of energy flow quality losses within the system. (Advanced) Analysis suggests that the irreversible losses of a component are not only determined by its own limited thermodynamic properties, but also by the effects of other components. Therefore, the losses of each component in the system can be considered... The losses are further decomposed according to certain relationships, and considerations of practical factors such as insufficient technical capabilities and economic constraints are incorporated, making the analysis results more valuable for practical engineering applications and facilitating the transformation of theoretical findings into engineering practice. (Advanced) Initially, analytical methods primarily analyzed refrigeration cycles. However, due to their significant advantages, they have gradually been developed as tools for evaluating other energy conversion systems, such as ORC systems. It is still rare to see advanced analytical methods applied to these systems. The analytical method was applied to the S-CO2 power cycle system, thus enabling advanced analysis of the S-CO2 power cycle. The analysis warrants extensive and in-depth research.

[0006] Based on the above analysis, the urgent technical problem that needs to be solved in the existing technology is: there are very few examples of advanced technologies in the current technology. The analytical method was applied to the S-CO2 power cycle system. Summary of the Invention

[0007] To address the problems existing in the prior art, this invention provides an advanced S-CO2 dual-turbine power generation system. Analytical methods and systems.

[0008] This invention is achieved as follows: an advanced S-CO2 dual-turbine power generation system. Analytical methods, including:

[0009] S1, using the process simulation software Aspen HYSYS to construct an S-CO2 dual-turbine power cycle simulation model;

[0010] S2, routine testing of the S-CO2 dual-turbine power generation system analyze

[0011] S3, for advanced system completion Analyze the potential for performance improvement in the system and its components;

[0012] S4, Investigate the relationship between irreversible losses within the system;

[0013] S5 proposes a priority order for component improvements.

[0014] Furthermore, to simplify the modeling and calculation of the cyclic system, the following assumptions are introduced:

[0015] ① The circulating system maintains steady-state operation;

[0016] ②The S-CO2 working fluid leaks during the circulation process;

[0017] ③ Ignore pressure and heat losses in the system piping;

[0018] ④ Ignoring the chemical composition of S-CO2 working fluid kinetic energy Potential energy Considering only its physics

[0019] According to the first law of thermodynamics, the heat transfer process in a circulating heat exchanger and the energy conversion process in a power plant satisfy the energy conservation equation:

[0020]

[0021] S-CO2 system net output power W net for:

[0022] W net =W PT +W CT -W comp (2)

[0023] In the formula, the output power W of the power turbine is... PT Core turbine output power (W) CT Compressor power consumption (W) comp Calculated using the following formulas respectively:

[0024]

[0025] In the formula, F represents the mass flow rate of the S-CO2 working fluid, in kg / s. sr The turbine split ratio is defined as the ratio of the S-CO2 mass flow rate through the power turbine to the total mass flow rate of the circulating S-CO2; h is... Figure 1 The specific enthalpy of the corresponding stream is expressed in kJ / kg; the subscripts PT, CT, and comp represent the power turbine, core turbine, and compressor in the system, respectively.

[0026] Heater load Q heat Cooler load Qcool Regenerator load Q recu Calculated using the following formulas respectively:

[0027]

[0028] In the formula, the subscripts heat, cool, and recu represent the heater, cooler, and regenerator in the system, respectively.

[0029] Furthermore, based on advanced The analytical method suggests that the irreversible loss in component k can be divided into the portion unaffected by other components and the portion affected by other components, i.e., the intrinsic loss. Losses and external sources loss:

[0030]

[0031] In the formula, These represent the internal sources of component k. Loss rate, external Loss rate, kW.

[0032] Referring to the thermodynamic cycle method, six sets of first-order hybrid cycles were constructed for the six main components for calculation. Then, 15 secondary hybrid loops were constructed by grouping the six main components into pairs to analyze the interaction of irreversible losses between the components:

[0033]

[0034] In the formula, The external source that exists due to the irreversible action of component k on component r (component r and component k are two different components). Loss rate, kW; In a two-stage hybrid cycle consisting of component k and component r, the value of component k is... Loss rate, kW; For the exogenous component k Loss rate, kW.

[0035] The irreversible loss in component k can be further divided into the part that cannot be eliminated due to objective limitations, and the part that can be overcome by improving the component or selecting a more suitable component, i.e., the intrinsic loss. Losses and external sources loss:

[0036]

[0037] In the formula, and Each represents the inevitability of the components. Loss rate and avoidable Loss rate, kW.

[0038] Furthermore, inevitably loss rate It can be calculated using the following formula:

[0039]

[0040] In the formula, Let be the inevitability index of component k.

[0041] Furthermore, the components The loss can be divided into four parts, and their relationship can be expressed as follows:

[0042]

[0043] In the formula, The unavoidable internal sources of component k Loss rate, avoidable endogenous Loss rate, unavoidable external factors Loss rate, avoidance of external factors Loss rate, kW.

[0044] Another object of the present invention is to provide an advanced implementation of the aforementioned S-CO2 dual-turbine power generation system. Advanced analytical methods for S-CO2 dual-turbine power generation systems Analysis system, including:

[0045] The simulation model building module uses the process simulation software Aspen HYSYS to build a simulation model of the S-CO2 dual-turbine power cycle;

[0046] conventional The analysis module performs routine analysis on the S-CO2 dual-turbine power generation system. analyze;

[0047] advanced The analysis module performs advanced analysis on the system. Analyze the potential for performance improvement in the system and its components;

[0048] The module on the interaction of irreversible losses explores the interaction of irreversible losses within the system.

[0049] The priority order for proposing module improvements and component improvements is as follows.

[0050] Another object of the present invention is to provide a computer device, the computer device including a memory and a processor, the memory storing a computer program, which, when executed by the processor, causes the processor to perform the advanced functions of the S-CO2 dual-turbine power generation system described above. The steps of the analysis method.

[0051] Another object of the present invention is to provide a computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to perform advanced functions of the S-CO2 dual-turbine power generation system. The steps of the analysis method.

[0052] Another object of the present invention is to provide an information data processing terminal, which includes the advanced S-CO2 dual-turbine power generation system described above. Analysis system.

[0053] Based on the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solution to be protected by this invention are as follows:

[0054] First, this invention constructs an S-CO2 dual-turbine power generation system, uses Aspen HYSYS software as a tool to simulate system operation, calls the REFPROP database to perform physical property calculations, and performs advanced system analysis. The analysis examines the potential for performance improvement within the system, explores the impact of irreversible losses within the system, discusses the priority order of component improvements, and compares them with conventional approaches. Comparison of analysis results. The research conclusions are as follows:

[0055] 1) Conventional Analysis results show that the heater and regenerator in the system are The most severely damaged component was the heater. The power loss rate is 569.17 kW, and the regenerator... The loss rate is 556.67kW, and both account for a significant portion of the system's total power consumption. The system accounted for 38.3% and 37.5% of the losses, respectively. The efficiency is 43.17%.

[0056] 2) Maintaining the same net output power of 1023.81kW, the system operates under unavoidable conditions. Efficiency can reach 54.93% under ideal conditions. The efficiency can reach 65.50%, theoretically the system There is room for improvement in efficiency of approximately 22.3%, but under objective conditions, the actual room for improvement is approximately 11.8%.

[0057] 3) External sources of system components The loss rate is 434.713 kW, which is in the total system power. The loss rate of 29.3% reveals a significant link between the irreversibility of key components. Among these, the components with the strongest irreversibility are the power turbine, core turbine, and regenerator. Improving these components can not only reduce their own... Losses can also reduce the external factors generated by its effects. loss.

[0058] 4) Advanced Analysis suggests that improvements should be prioritized for the heater and regenerator, both of which can avoid internal factors. The highest loss rates were recorded at 159.072 kW and 117.223 kW, respectively. These were followed by the power turbine, compressor, and core turbine, with the cooler ranking last.

[0059] 5) Conventional Analysis revealed the cooler The loss rate was 168.054kW, ranking third, while the advanced Analysis indicates that the internal power source, which can be avoided, is only 11.925kW, and its importance for improvement has dropped to the bottom, thus increasing the priority of improvements to the power turbine, compressor, and core turbine. Attached Figure Description

[0060] Figure 1 This is a schematic diagram of the S-CO2 dual-turbine Brayton cycle system provided in an embodiment of the present invention;

[0061] Figure 2 This is a schematic diagram of the simulation interface of the S-CO2 dual-turbine power generation system provided in the embodiment of the present invention in Aspen HYSYS;

[0062] Figure 3 This is a key component of the dual-turbine S-CO2 power generation system provided in this embodiment of the invention. Schematic diagram of loss distribution;

[0063] Figure 4 The compressor provided in this embodiment of the invention is subject to irreversible action by its components. Schematic diagram of loss distribution;

[0064] Figure 5 The external source of irreversible action on the power turbine provided in the embodiments of the present invention is the component. Schematic diagram of loss distribution;

[0065] Figure 6 The core turbine provided in this embodiment of the invention is subject to irreversible action by its components. Schematic diagram of loss distribution;

[0066] Figure 7 The heater provided in this embodiment of the invention is subject to irreversible action by the component. Schematic diagram of loss distribution;

[0067] Figure 8 The external source of the irreversible action of the component on the cooler provided in the embodiments of the present invention is... Schematic diagram of loss distribution;

[0068] Figure 9 The external source of the irreversible action of the components in the regenerator provided in this embodiment of the invention is... Schematic diagram of loss distribution;

[0069] Figure 10 The main components of the system provided in the embodiments of the present invention can avoid Loss rate and classification of endogenous and exogenous sources Loss rate distribution diagram;

[0070] Figure 11 This is an advanced feature provided in the embodiments of the present invention. Analysis and routine A diagram illustrating the component improvement priorities under analysis;

[0071] Figure 12 The advanced S-CO2 dual-turbine power generation system provided in this embodiment of the invention Flowchart of the analysis method;

[0072] Figure 13 The advanced S-CO2 dual-turbine power generation system provided in this embodiment of the invention Analyze the system structure diagram. Detailed Implementation

[0073] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0074] 1. Model Establishment

[0075] 1.1 S-CO2 Dual-Turbine Power Generation System Model

[0076] The S-CO2 Brayton cycle boasts advantages such as high efficiency, compact layout, and versatility in various applications. This invention, targeting flue gas waste heat recovery applications, constructs an S-CO2 dual-turbine power generation system. Its structural feature is based on a simple regenerative S-CO2 Brayton cycle, but with a CO2 working fluid split at the heater outlet. The CO2 working fluid is distributed to two turbines according to a specific split ratio, expands to perform work, and then converges and is transported to the next device. The system flow is as follows: Figure 1 As shown.

[0077] The S-CO2 working fluid flows through the compressor (1-2) and is pressurized from near-critical point to far-critical point. Then, it passes through the regenerator (2-3) to receive waste heat from the turbine exhaust gas and is heated. It then flows through the heater (3-4) to recover waste heat from the high-temperature flue gas (7-8) and is further heated. At point 4, the S-CO2 working fluid is split into two streams, 4P and 4C, which are delivered to the power turbine (4P-5P) and the core turbine (4C-5C) respectively for expansion, work, and output of electrical energy. Then, the exhaust gas streams 5P and 5C merge into stream 5, which is initially cooled in the regenerator (5-6) and further cooled to near-critical point by cooling water (9-10) in the cooler (6-1), completing the cycle.

[0078] 1.2 Thermodynamic Analysis Model

[0079] 1.2.1 Cyclic Simulation and Verification

[0080] To simplify the modeling and calculation of cyclic systems, the following assumptions are introduced:

[0081] ① The circulating system maintains steady-state operation;

[0082] ②The S-CO2 working fluid leaks during the circulation process;

[0083] ③ Ignore pressure and heat losses in the system piping;

[0084] ④ Ignoring the chemical composition of S-CO2 working fluid kinetic energy Potential energy Considering only its physics

[0085] According to the first law of thermodynamics, the heat transfer process in a circulating heat exchanger and the energy conversion process in a power plant satisfy the energy conservation equation:

[0086]

[0087] S-CO2 system net output power W net for:

[0088] W net =W PT +W CT -W comp (2)

[0089] In the formula, the output power W of the power turbine is... PT Core turbine output power (W) CT Compressor power consumption (W) comp Calculated using the following formulas respectively:

[0090]

[0091] In the formula, F represents the mass flow rate of the S-CO2 working fluid, in kg / s. sr The turbine split ratio is defined as the ratio of the S-CO2 mass flow rate through the power turbine to the total mass flow rate of the circulating S-CO2; h is... Figure 1 The specific enthalpy of the corresponding stream is expressed in kJ / kg; the subscripts PT, CT, and comp represent the power turbine, core turbine, and compressor in the system, respectively.

[0092] Heater load Q heat Cooler load Q cool Regenerator load Q recu Calculated using the following formulas respectively:

[0093]

[0094]

[0095] In the formula, the subscripts heat, cool, and recu represent the heater, cooler, and regenerator in the system, respectively.

[0096] This invention uses Aspen HYSYS software to simulate the constructed S-CO2 dual-turbine power generation system, such as... Figure 2 As shown. Given the unique physical properties of CO2 working fluid in the supercritical state, selecting an appropriate method for calculating its properties is crucial. Therefore, the Refprop equation of state was chosen as the simulation method for calculating its properties, and its good accuracy has been verified.

[0097] The basic parameters of the cycle and the comparison of simulation results are shown in Table 1 and Table 2, respectively. The simulation results show that the maximum relative error is -1.62% of the core turbine output power, while the minimum relative error is 0.38% of the regenerator load. This indicates that the results calculated by the simulation model are in good agreement with the experimental results, and the error is within the acceptable range. The simulation model used in the study has good reliability.

[0098] Table 1 Basic parameters of the S-CO2 twin-turbine power generation system

[0099]

[0100] Table 2 Verification of Cyclic Simulation Calculation Results

[0101]

[0102] 1.2.2 Conventional Analysis Model

[0103] To distinguish the advanced Analysis, which will be commonly used here The analytical model is called conventional. Analysis model, this analysis model is mainly based on Equilibrium equations are used to quantify the irreversible losses of the entire system and its individual components, at each state point. The value can be calculated using the following formula:

[0104]

[0105] In the formula, the subscript i represents Figure 1 State points 1-10 are given, with subscript 0 indicating environmental conditions; s is the specific entropy of the fluid, kJ / (kg·K).

[0106] Based on the concept of "input-effective input-loss", the components in the system The equilibrium equation can be expressed as:

[0107]

[0108] In the formula, These represent the inputs of component k respectively. Valid input Loss, kW.

[0109] For the system as a whole, Equilibrium equations and Efficiency can be expressed by the following formulas:

[0110]

[0111] In the formula, the subscript tot is used to represent the entire system; Representative system Dissipation, kW; ε sys Represents the system as a whole efficiency.

[0112] Conventional construction of each component-level system The detailed analysis and calculation model can be found in Table 3.

[0113] Table 3. Individual components and the overall system Computational model

[0114]

[0115] 1.2.3 Advanced Analysis Model

[0116] Based on advanced The analytical method suggests that the irreversible loss in component k can be divided into the portion unaffected by other components and the portion affected by other components, i.e., the intrinsic loss. Losses and external sources loss:

[0117]

[0118] In the formula, These represent the internal sources of component k. Loss rate, external Loss rate, kW.

[0119] This invention, referencing the thermodynamic cycle method, constructs six sets of first-order hybrid cycles for each of the six main components, used for calculation. Then, 15 secondary hybrid loops were constructed by grouping the six main components into pairs to analyze the interaction of irreversible losses between the components:

[0120]

[0121] In the formula, The external source that exists due to the irreversible action of component k on component r (component r and component k are two different components). Loss rate, kW; In a two-stage hybrid cycle consisting of component k and component r, the value of component k is... Loss rate, kW; For the exogenous component k Loss rate, kW.

[0122] The irreversible loss in component k can be further divided into the part that cannot be eliminated due to objective limitations, and the part that can be overcome by improving the component or selecting a more suitable component, i.e., the intrinsic loss. Losses and external sources loss:

[0123]

[0124] In the formula, and Each represents the inevitability of the components. Loss rate and avoidable Loss rate, kW.

[0125] Inevitable loss rate It can be calculated using the following formula:

[0126]

[0127] In the formula, Let be the inevitability index of component k.

[0128] In summary, the components The loss can be further divided into four parts, and their relationship can be expressed as follows:

[0129]

[0130]

[0131] In the formula, The unavoidable internal sources of component k Loss rate, avoidable endogenous Loss rate, unavoidable external factors Loss rate, avoidance of external factors Loss rate, kW.

[0132] 2. Conventional analyze

[0133] conventional Analyzing the irreversible losses of key components in a system is a crucial step in assessing the system's potential for improvement. This is achieved through calculations of thermodynamic processes... Loss rate achievement, compressor, power turbine, core turbine, heater, condenser, regenerator Loss composition ratio, for example Figure 3 As shown, the heater and regenerator occupy the space of the system. The vast majority of the losses occurred in the coolers, while the losses to the power turbines, compressors, and core turbines accounted for a smaller proportion.

[0134] In a dual-turbine S-CO2 power generation system, the heater and the regenerator Losses are the primary source of system irreversibility. Under design operating conditions, the heater... loss rate The power output is 569.17 kW, and the regenerator is... loss rate The total power is 556.67 kW, and the two account for a significant portion of the system's total power. These accounted for 38.3% and 37.5% of the losses respectively, totaling 75.8%, which had a significant impact on the overall system performance. The magnitude of the heat loss has a decisive influence, which can be attributed to the high heat exchange temperature difference during the heat exchange process. Studies have found that the LMTD values ​​of the heater and regenerator in the S-CO2 system during heat exchange reach 68.79K and 61.43K respectively, both of which are at a high level.

[0135] cooler loss rate It is 168.05 kW, which is lower than that of the heater and regenerator. The loss value, in the total system Only 11.3% of the losses were due to the cooling water temperature being close to the critical temperature of the CO2 working fluid, resulting in a small heat exchange temperature difference in the cooler. Data shows that its LMTD value is only 17.14K, which is at a low level among the three heat exchange processes in the system. This is due to the cooler's... The loss is lower than that of heaters and regenerators. The main reasons for the loss.

[0136] Power equipment in a dual-turbine S-CO2 power generation system The total losses accounted for only 12.9%, compressor loss rate The power turbine has a power output of 69.28 kW. loss rate The core turbine has a power output of 76.84 kW. loss rate The total power output is 44.84 kW, and the three components account for a significant portion of the system's total power. The losses accounted for 4.7%, 5.2%, and 3.0% respectively, all at extremely low levels, reflecting the good performance of the system's power equipment, with isentropic efficiencies reaching approximately 80%. If classified according to system output and power-consuming equipment, the turbine... The total loss rate is 121.68kW, accounting for 8.2% of the system. This is higher than the compressor's share, but still lower than the cooler's share.

[0137] In summary, by quantifying and comparing the irreversible losses of the main components of the system, it can be seen that the system's... Losses are concentrated in the heaters and regenerators, followed by the coolers, while losses occur in the compressors, power turbines, and core turbines. The losses are minimal for the system. This also means that when planning improvements to system components, heaters and regenerators should be the top priority, as improvements to these components can bring the greatest benefits to the system. The next priority is coolers, followed by power turbines, compressors, and core turbines.

[0138] 3 Advanced analyze

[0139] 3.1 System Performance Analysis

[0140] In advanced In the analysis, operating conditions are categorized into three types: the first is the actual conditions of the main components under real-world operating conditions; the second is the ideal conditions of the components after ignoring all process losses; and the third is the unavoidable conditions under which existing technology allows the components to achieve optimal performance. Both ideal and unavoidable conditions are based on actual conditions. Table 4 lists the key parameters of the main components under actual, ideal, and unavoidable conditions. Pinch temperature difference and pressure drop are used to represent parameters affecting the losses of the heater, cooler, and regenerator, while isentropic efficiency is used to represent parameters affecting the losses of the turbine and compressor.

[0141] Table 4 Key parameters of major components under actual, ideal, and unavoidable conditions.

[0142]

[0143] When all components of the system operate under actual conditions, the thermodynamic parameters corresponding to each key state point in the actual cycle can be obtained. These mainly include the fluid's mass flow rate, temperature, pressure, specific enthalpy, specific entropy, and... The specific values ​​for the rates are listed in Table 4.

[0144] Table 4 Thermodynamic parameters of the system under actual operating conditions

[0145]

[0146] Based on the actual cycle, and with reference to the setting of ideal and unavoidable conditions, ideal and unavoidable cycles were constructed, and the specific parameters of each state point are given in Table 5 and Table 6, respectively.

[0147] Table 5 Thermodynamic parameters of the system under ideal operating conditions

[0148]

[0149] Based on the aforementioned settings, the net output power of both the ideal cycle and the unavoidable cycle is equal to the net output power of the actual cycle, thus ensuring system consistency in scale. Comparing the system's operating data under the three conditions, with the same net benefit, the actual cycle requires a larger flue gas flow rate and cooling water flow rate to ensure system profitability, while the ideal cycle and the unavoidable cycle require lower flow rates. Furthermore, the ideal cycle requires a smaller flow rate than the unavoidable cycle, indicating that the closer the system is to the ideal state, the higher its operating efficiency and the less input is required for a given output. (System under ideal conditions) The efficiency reached 65.50%, which sets an upper limit for improving system performance, compared to 43.17% under actual conditions. Regarding efficiency, the system has approximately 22% room for improvement. Under unavoidable conditions, the system's efficiency... The efficiency can reach 54.93%, which represents the maximum efficiency the system can achieve through technical means; it is the upper limit of system performance improvement based on real-world conditions. Furthermore, by comparing systems under ideal and unavoidable conditions... Efficiency, it can be seen that there is a rate of 10.57%. Efficiency was hampered by technological barriers and could not be improved, compared to 43.17% under actual conditions. Efficiency, System Efficiency can be improved by nearly 12% through technological means.

[0150] Table 6. Thermodynamic parameters of the system under unavoidable conditions.

[0151]

[0152] 3.2 Endogenous and Exogenous Loss Analysis

[0153] Use advanced The analysis method will exist in the system The loss was divided into intrinsic and extrinsic components, and the results are shown in Table 7. Among them, the intrinsic... Loss refers to the loss caused by the inherent performance defect of a component, or external loss. Loss refers to the loss incurred by a component due to performance defects in other components and other factors. It describes the loss of a component. The source of the loss.

[0154] In the S-CO2 dual-turbine power generation system, the regenerator's internal source loss rate It is 469.387kW, which is higher than the internal power of the other components. Loss rate, and its external source loss rate With a power output of only 87.283 kW, this reveals that its performance is not easily affected by factors of other components, and is mainly determined by the intrinsic factors of these components. For the heater, its total... loss rate Slightly higher than the total height of the regenerator loss rate But its internal source loss rate But lower than The power consumption is 395.654 kW, indicating that the irreversibility of the heater is more significantly affected by other inefficient components. Numerically, the external power source of the heater is... loss rate It is also the highest among system components, at 173.514 kW. (Internal power source of the cooler) loss rate With only 54.650kW, its external power source loss rate However, it reaches 113.404kW, which is the highest among all components. The fact that the external source of the loss is higher than the internal source reflects that the cooler is the component most severely affected by external factors, and its interaction with these factors warrants further analysis.

[0155] Table 7 Internal and External Sources of the System's Main Components loss rate

[0156]

[0157] Due to the system's power equipment The loss rate is low, and the internal components of the compressor, power turbine, and core turbine are relatively low. Loss rate and external The loss rate was also relatively low, especially for the compressor. Loss of endogenous components Slightly higher than the exogenous portion And two turbines Loss of endogenous components All were several times higher than the exogenous portion Indicates turbine The loss is mainly determined by its own performance deficiencies, while the compressor is also subject to other constraints in addition to its own factors.

[0158] At the system level, external The sum of loss rates The total power output is 434.713 kW, which is part of the system's total power output. loss rate This accounts for 29.3%, indicating a significant connection between the irreversibility of key components and external factors affecting the heater. loss rate In the system It accounted for 11.7% of the losses, the highest among all components; therefore, in order to reduce the larger losses in the heater... To mitigate losses, it is not only necessary to improve the heater itself, but also to reduce the impact of other components on the irreversible losses of the heater.

[0159] 3.3 Inevitable and Avoidable Loss Analysis

[0160] Inevitable Losses are those that cannot be reduced due to objective factors such as technology and economics, and are therefore avoidable. Losses are those that can be reduced through appropriate technical means, representing the degree of improvement that a component can undergo. Table 8 lists the unavoidable losses in the S-CO2 dual-turbine power generation system. loss rate and avoidable loss rate The numerical value.

[0161] Table 8. Unavoidable and Avoidable Key Components of the System loss rate

[0162]

[0163] In the system After classifying losses according to unavoidable conditions, the unavoidable losses of the regenerator... loss rate Up to 417.649kW, in total unavoidable The loss rate accounts for 45.9%, representing a significantly large share. Although the heat capacity difference between the high-pressure and low-pressure sides of the regenerator naturally decreases during the transition from actual to unavoidable conditions, the reduction is small. Therefore, for the regenerator... The reduction in losses appears to be quite limited. This means that even after improvements, the regenerator still suffers from significant losses. The loss cannot be eliminated, but it can be avoided. loss rate With only 139.021kW, it accounts for only a small percentage of its total loss rate The figure of 25% indicates that improving the regenerator is less effective in reducing irreversible losses, and more consideration should be given to changing the structure or design parameters of the cycle.

[0164] Similar to the case of regenerators, heaters and coolers The potential for reducing losses is also relatively limited, mainly due to the inevitability of both. loss rate 338.709 kW 105.709kW are all higher than their respective avoidable values. The loss suggests room for improvement of approximately 40%.

[0165] Conversely, the power equipment in the S-CO2 dual-turbine power generation system A significant portion of the losses can be reduced or avoided. loss rate Each occupies their respective The loss rates of 78.0%, 69.0%, and 79.1% indicate that improvements to these power equipment are less constrained by technology, and reducing irreversible losses is highly feasible. From actual to irreversible cycles, the isentropic efficiency of the turbine increases to 95.00%, and the entropy increase in the CO2 working fluid expansion process decreases by 63.8% and 73.8% respectively. This effectively increases the enthalpy difference between the inlet and outlet, allowing the improved turbine to provide greater output power to the system. Similarly, the power consumption required by the compressor will also be lower. Nevertheless, due to the avoidable... The loss rates of each power unit are several times lower than those of the heater and regenerator, so their priority for improvement is still debatable.

[0166] At the system level, it is always unavoidable loss rate With 910.505 kW, accounting for 61.3% of the market share, this result illustrates that in conventional... It is necessary to consider the limitations of real-world technology in the context of analysis; advanced Analysis can improve the reliability of component improvement plans.

[0167] 3.4 Correlation Analysis of Irreversible Losses of Key Components

[0168] Given the strong interrelationships between components during the operation of the S-CO2 dual-turbine power generation system, it is necessary to further discuss the interaction of irreversible losses among these components, and to consider the external factors affecting the components. The loss rate was divided according to the component that performed the action.

[0169] compressor external source The distribution of losses is as follows Figure 4 As shown, the compressor's exogenous loss rate This accounts for 59.9%, indicating that the compressor is significantly affected by the combined effects of the internal connections of other components. Secondly, the turbine plays a significant role in the compressor's operation, accounting for 26.6% in total, with the power turbine being the most prominent component. 17.1%, core turbine It accounts for 9.5%. In comparison, the irreversible losses of each heat exchanger have a greater impact on the compressor. The impact of the loss is relatively weak, affecting the heater, regenerator, and cooler. They accounted for only 6.4%, 5.1%, and 2.1% respectively. This indicates that reducing external sources... Improving compressor performance mainly relies on modifying the system structure or enhancing turbine performance.

[0170] like Figure 5 As shown, the external source of the power turbine The losses were also significantly affected by the exogenous factors. This accounts for 42.0%. Similar to compressors, power turbines... The damage was primarily caused by the power equipment, with the core turbine playing the most significant role. It accounted for 29.2%, followed by the compressor's functional parts. It accounts for 16.4%. Among heat exchange equipment, only the heater plays a relatively prominent role. It accounts for 11.8%, while the function of coolers and regenerators is... With a share of only 0.2% and 0.4%, these figures can be ignored.

[0171] from Figure 6 It can be seen that the core turbine is external. The loss distribution is largely consistent with that of the power turbine, but the power turbine has a greater impact on the core turbine. It accounted for 40.0%, exceeding the exogenous. loss rate In other words, improving both turbines in a dual-turbine system will benefit both of them from external sources. Reduction of losses.

[0172] heater external source The distribution of losses is as follows Figure 7 As shown, the heater is an external source The portion of the loss affected by the regenerator This accounts for 36.3%, indicating that the regenerator is the component most affected. Improving the regenerator is key to reducing external factors affecting the heater. Effective ways to mitigate losses. Secondly, the turbine also has a strong impact on the heater. The total share was 32.9%. In addition, The 20.3% proportion also indicates that the heater is externally sourced. The loss will be influenced to some extent by exogenous factors. In comparison, It accounts for only 1.3%, which shows that the cooler has a negligible impact on the heater.

[0173] like Figure 8 As shown, unlike the heater, the cooler is externally sourced. The loss is more significantly influenced by exogenous factors. This accounts for 56.4%, indicating a reduction in external sources of cooling. Losses need to be addressed by improving the cycle structure or optimizing the cycle's operating parameters. Secondly, the regenerator has the greatest impact on the cooler at the component level. Accounting for 26.9%, improving the regenerator can also reduce the cooler's capacity to some extent. Loss. The remaining components have a relatively weak effect on the cooler, and the external forces acting upon them are... The loss rate is between 2.7% and 6.4%. Considering that the aforementioned components are also less affected by the cooler, it can be concluded that the interaction between the cooler and the compressor, power turbine, core turbine, and heater is weak.

[0174] external source of regenerator The distribution of losses is as follows Figure 9 As shown, the part where the power turbine works. It accounts for as much as 39.1%, having the strongest effect on the regenerator, while also contributing to the core turbine's function. This also accounted for 21.7%, with the total effect of the turbine on the external source of the regenerator. Losses accounted for 60.8% of the total, indicating that improvements to the turbine are particularly beneficial to the regenerator. Reduction of losses. Unlike the greater impact of the regenerator on the heater and condenser, the heater and condenser have a greater impact on the regenerator. The effect of the loss is extremely limited. They account for only 0.9% and 4.2% respectively. Furthermore, the exogenous component contributes to the regenerator... The loss also plays a role to some extent. The percentage was 27.7%, but its value was negative, meaning that simply improving the circulation structure did not help the external source of the regenerator. In addition to reducing losses, improvements to other components should be considered.

[0175] In summary, when improving the power turbine, core turbine, and regenerator, it is possible not only to reduce the cost of the improved components themselves... The losses are also expected to be reduced simultaneously, along with the significant external impact on other components. Loss. Exogenous components contribute to the external forces affecting each part. The losses all have a considerable impact, so improvements to the loop design need to be considered.

[0176] 3.5 Component Improvement Priority Analysis

[0177] To propose more reliable component improvement schemes to reduce irreversible losses in the system and thus improve system performance, advanced [technology / methods] are used. The analytical model further distinguishes between the unavoidable and the avoidable in the system. The loss rate was further decomposed into internal and external sources, resulting in unavoidable internal sources, unavoidable external sources, avoidable internal sources, and avoidable external sources. The loss rate results are listed in Table 9.

[0178] Table 9: Unavoidable internal sources, unavoidable external sources, avoidable internal sources, and avoidable external sources of the system. loss rate

[0179]

[0180] Because an unavoidable part is the system The loss is inherent in the problem and cannot be eliminated by improving components or other technical means; therefore, this part... Losses are usually not the focus. Component improvements should begin with feasibility, focusing on the avoidability of losses in key components. Loss rate and the segmented avoidable intrinsic and avoidable extrinsic sources The distribution of loss rates is as follows Figure 10 As shown.

[0181] It can be seen that the heater has the greatest potential for avoidance in the system. The components with the highest loss rate accounted for 40.1%, which could be avoided. The internal component of the loss rate accounted for 69.0%, while the external component accounted for 31.0%. Although there was a significant external component, the loss was largely due to the heater itself. The loss rate is numerically higher than that of other components, which avoids internal factors. loss rate The heater is significantly the highest among all components, indicating that, considering both feasibility and benefits, it should be considered a priority component for improvement.

[0182] For the regenerator, the aforementioned total loss rate Only slightly lower than the heater But after the advanced Analysis results show that it can avoid some Significantly lower than the heater In the system, it can always be avoided Only 24.2% of the losses were due to internal factors, so despite the 84.3% endogenous component, its... Still lower than the heater This means advanced Analysis indicates that improvements to the regenerator should be prioritized over those to the heater.

[0183] In terms of power equipment, the power turbine, core turbine, and compressor are avoidable. loss rate Each accounts for a portion of the total avoidable The loss rates were 9.2%, 6.2%, and 9.4%, with the compressor accounting for a slightly higher proportion than the power turbine and core turbine. However, due to the external components of both turbines... Within its own avoidability These accounted for only 23.2% and 27.0% of the losses respectively, lower than those of compressors. It accounts for 44.2%, therefore, according to the avoidable endogenous Losses sorted from largest to smallest are as follows: Improvements to the power turbine should take precedence over those to the compressor and core turbine.

[0184] advanced Analysis shows that the cooler can avoid internal sources. loss rate It has the lowest percentage in the system because of its The avoidable portion of the loss is largely influenced by factors not related to the components themselves. The proportion is as high as 80.9%, endogenous part Only 19.1% remains, which means that improving the system's cooler is crucial for reducing its... The impact of the loss is relatively small, and considering the aforementioned irreversibility of the cooler, the external factors affecting other components are relatively minor. The impact of the losses is also relatively small, so it can be concluded that the benefits of the cooler improvement are poor, and its priority should be ranked last among the components.

[0185] In summary, after considering the feasibility and benefits of component improvements, the components that should be prioritized for improvement in the S-CO2 dual-turbine power generation system are the heater and the regenerator, followed by the power turbine, compressor, and core turbine, with the cooler having the lowest priority.

[0186] 3.6 Conventional Analysis and Advanced Comparative discussion of analysis results

[0187] After advanced Analysis reveals that the results are consistent with conventional methods. The analysis results differ, mainly in the ranking of the priorities for component improvements. Figure 11 The comparison between the two analysis results is shown, with the upper red area representing advanced analysis. The analysis results show that the lower gray area represents the conventional... The results of the analysis have identified the priorities for improvement.

[0188] advanced Analysis and routine The analyses all prioritized heaters and regenerators as the components for improvement, but the degree of improvement varied somewhat. loss Percentage and avoidable endogenous loss The proportions are respectively used as regular Analysis and advanced Analyzing parameters that quantify the importance of component improvements allows for observation of advanced... The analysis showed that the importance of improving the heater slightly increased (38.3% → 41.3%), while the importance of improving the regenerator decreased (37.5% → 30.5%), mainly due to the regenerator... The losses are largely unavoidable and constrained by current technological limitations. Power turbines and core turbines are in advanced... The importance of both components increased by two times in the analysis, with power turbines rising from fourth priority to third (5.2% → 10.6%), and core turbines rising from sixth priority to fifth (3.0% → 6.7%). This is attributed to the fact that... A significant portion of the losses are avoidable due to internal factors, indicating substantial room for improvement and feasibility in component enhancement. The importance of compressor improvement has risen from fifth to fourth place (4.7% → 7.8%), but its improvement is not as significant as that of turbines, limited by their inherent limitations. A significant portion of the losses originated from external factors. The component with the most significant change in importance was the cooler, which plummeted from third priority to last (11.3% → 3.1%). This was partly due to its… The unavoidable portion of the losses is small, partly because its internal components account for less than 20%, making it the component most affected by factors other than its own. Reducing its losses should start with improving the regenerator or optimizing the cycle design.

[0189] In summary, advanced Analysis in routine Based on the analysis, some adjustments were made, taking into account the feasibility of component improvements and the causes of losses. This provides more reference information for further system improvements, makes the results more reliable, and helps engineers deepen their understanding of irreversible system losses.

[0190] like Figure 12 As shown, the advanced S-CO2 dual-turbine power generation system provided in this embodiment of the invention... The analytical method is characterized by comprising:

[0191] S1, using the process simulation software Aspen HYSYS to construct an S-CO2 dual-turbine power cycle simulation model;

[0192] S2, routine testing of the S-CO2 dual-turbine power generation system analyze

[0193] S3, for advanced system completion Analyze the potential for performance improvement in the system and its components;

[0194] S4, Investigate the relationship between irreversible losses within the system;

[0195] S5 proposes a priority order for component improvements.

[0196] like Figure 13 As shown, the advanced S-CO2 dual-turbine power generation system provided in this embodiment of the invention... The analysis system is characterized by comprising:

[0197] The simulation model building module uses the process simulation software Aspen HYSYS to build a simulation model of the S-CO2 dual-turbine power cycle;

[0198] conventional The analysis module performs routine analysis on the S-CO2 dual-turbine power generation system. analyze;

[0199] advanced The analysis module performs advanced analysis on the system. Analyze the potential for performance improvement in the system and its components;

[0200] The module on the interaction of irreversible losses explores the interaction of irreversible losses within the system.

[0201] The priority order for proposing module improvements and component improvements is as follows.

[0202] An application embodiment of the present invention provides a computer device, which includes a memory and a processor. The memory stores a computer program, and when the computer program is executed by the processor, the processor causes the processor to perform advanced functions of an S-CO2 dual-turbine power generation system. The steps of the analysis method.

[0203] An application embodiment of the present invention provides a computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to perform advanced functions of an S-CO2 dual-turbine power generation system. The steps of the analysis method.

[0204] An application embodiment of the present invention provides an information data processing terminal, which includes an advanced analysis system for S-CO2 dual-turbine power generation systems.

[0205] It should be noted that embodiments of the present invention can be implemented in hardware, software, or a combination of both. The hardware portion can be implemented using dedicated logic; the software portion can be stored in memory and executed by a suitable instruction execution system, such as a microprocessor or dedicated-design hardware. Those skilled in the art will understand that the above-described devices and methods can be implemented using computer-executable instructions and / or included in processor control code, for example, such code provided on a carrier medium such as a disk, CD, or DVD-ROM, a programmable memory such as read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. The devices and modules of the present invention can be implemented by hardware circuitry such as very large-scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, or programmable hardware devices such as field-programmable gate arrays, programmable logic devices, etc., or by software executed by various types of processors, or by a combination of the above-described hardware circuitry and software, such as firmware.

[0206] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions, and improvements made by those skilled in the art within the scope of the technology disclosed in the present invention, and within the spirit and principles of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An S-CO2 dual turbine power generation system high level An analysis method characterized by, Comprising: S1, using process simulation software Aspen HYSYS to build a simulation model of S-CO2 double turbine power cycle; S2, to carry out routine analysis on the S-CO2 double turbine power generation system analysis; S3, complete advanced Analysis, analyze system and component performance for improvement opportunities; S4, exploring the role of internal irreversible loss of the system; S5, proposing the priority order of component improvement; Conventional Analysis is based on Balance equations, for quantifying the irreversibility losses of the system as a whole and of each of its components, each state point The values can be calculated by the following formula: In the formula, subscript i represents state points 1-10, and subscript 0 represents environmental conditions; s is the specific entropy of the fluid, kJ / (kg·K); Based on the concept of "input-output-loss", the system components are The balance equation can be expressed as: wherein respectively represent the input rate of component k input rate, output rate, loss rate, kW; For the system as a whole, the balance equation and The efficiencies can be expressed by the following equations, respectively: where the subscript tot is used to indicate the system as a whole; representing the system dissipation, kW; ε sys representing the system as a whole efficiency; Based on the advanced The analysis method, the irreversible losses in component k can be divided into a part that is not affected by the remaining components, and a part that is affected by the remaining components, i.e. endogenous losses and exogenous losses: wherein represents the endogenous loss rate of component k represents the exogenous loss rate of component k represents the exogenous loss rate of component k, kW; Referring to the thermodynamic cycle method, six groups of first-order mixed cycles were constructed for the six main components, respectively, for the calculation The six main components were then constructed in two groups to form 15 groups of second-order mixed cycles for analyzing the effect of the irreversible loss between components: wherein is the exogenous to component k due to the irreversible action of component r loss rate, kW, component r and component k are two different components; is the exogenous to component k due to the irreversible action of component r loss rate, kW; is the exogenous to component k due to the irreversible action of component r loss rate, kW; The irreversible losses in component k can also be divided into a part that is limited by objective conditions and cannot be eliminated, and a part that can be overcome by improving the component or by selecting a more suitable component, i.e. endogenous losses and exogenous losses: wherein and represent the unavoidable and avoidable loss rates, kW.

2. The S-CO2 dual turbo power system of claim 1 wherein An analysis method characterized by In order to simplify the modeling and calculation of the S-CO2 double turbine power generation system, the following assumptions are introduced: ①The S-CO2 double turbine power generation system remains in steady-state operation; ②There is no leakage of S-CO2 working medium in the cycle process; ③The pressure loss and heat loss of the system pipeline are ignored; (4) Without considering the chemical Kinetic energy Potential energy Only considering its physical 3. The S-CO2 dual turbo power system of claim 1 wherein An analysis method characterized by According to the first law of thermodynamics, the heat transfer process in the cycle heat exchanger and the energy conversion process of the power equipment satisfy the energy conservation equation: S-CO2 system net output power W net is: W net = W PT + W CT - W comp (2) wherein the power turbine output power W PT , the core turbine output power W CT , the compressor consumption power W comp are calculated by the following equations, respectively: wherein F represents the mass flow rate of S-CO2, kg / s; F sr is the split ratio of the turbine, defined as the ratio of the mass flow rate of S-CO2 through the power turbine to the total mass flow rate of S-CO2 in the cycle; h is the specific enthalpy of the corresponding stream, kJ / kg; subscripts PT, CT, comp represent the power turbine, the core turbine, the compressor in the system, respectively; Heater duty Q heat Cooler duty Q cool Reboiler duty Q recu respectively calculated by the following equations: In the formula, heat, cool, and recu represent the heater, cooler, and regenerator in the system, respectively.

4. The S-CO2 dual turbo power system of claim 1 wherein An analysis method characterized by inevitable loss rate may be calculated by the following equation: wherein is the unavoidable index of the component k.

5. The S-CO2 double turbo power generation system high level of claim 1 An analysis method characterized by, of the component The losses can be divided into four parts, the relationship of which can be expressed as: wherein respectively the unavoidable endogenous loss rate of component k the avoidable endogenous loss rate, kW the unavoidable exogenous loss rate, kW the avoidable exogenous loss rate, kW the unavoidable exogenous loss rate, kW 6. An advanced implementation of the S-CO2 dual-turbine power generation system as described in any one of claims 1 to 5 Advanced analytical methods for S-CO2 dual-turbine power generation systems Analysis system, characterized in that, Comprising: a simulation model construction module, using process simulation software Aspen HYSYS to build a simulation model of S-CO2 double turbine power cycle; Conventional analysis module, to conduct a conventional analysis of the S-CO2 dual turbine power generation system analysis; Advanced an analysis module to complete an advanced analysis of the system analysis, analyzing the system and component performance for opportunities for improvement; an irreversible loss role relationship module, analyzing the role of internal irreversible loss of the system; a priority order proposal module, proposing the priority order of component improvement.

7. A computer device comprising a memory and a processor, the memory storing a computer program, the computer program, when executed by the processor, causing the processor to perform the steps of the method of any one of claims 1-5. the steps of the method of analysis.

8. A computer readable storage medium storing a computer program, which, when executed by a processor, causes the processor to perform the steps of the method of any one of claims 1 to 5. the steps of the method of analysis.

9. An information data processing terminal, the information data processing terminal comprising the S-CO2 dual turbo-generator system advanced analysis system of claim 6.

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