Advanced analysis method and system for S-CO2 double-turbine power generation system

Abstract

The invention belongs to but not limited to the technical field of # imgabs0 # analysis, and particularly relates to an advanced # imgabs1 # analysis method and system for an S-CO2 double-turbine power generation system, and the method comprises the steps: S1, constructing an S-CO2 double-turbine power cycle simulation model by using process simulation software Aspen HYSYS; s2, conventional # imgabs2 analysis is carried out on the S-CO2 double-turbine power generation system; S3, advanced # imgabs3 analysis is completed for the system, and the improvement space of the system and component performance is analyzed; s4, exploring the action relationship of irreversible loss in the system; and S5, proposing a priority sequence of component improvement. According to the method, an S-CO2 double-turbine power generation system is constructed, Aspen HYSYS software is used as a tool to simulate system operation, a REFPROP database is called to perform physical property calculation, advanced # imgabs4 # analysis is performed on the system, the improvement space of system performance is analyzed, the action relation of irreversible loss in the system is explored, the priority sequence of component improvement is discussed, and the system performance is improved. And discussing the comparison with the conventional # imgabs5 # analysis result.

Description

Technical Field

[0001] The present invention belongs to but is not limited to The technical field of analysis, in particular to a S-CO 2 Twin Turbine Power Generation System Advanced Analysis methods and systems. Background Art

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

[0003] As early as the 1960s, Feher first proposed the S-CO2 power cycle, but due to the insufficient level of key equipment manufacturing technology at the time, it was difficult to meet engineering needs and received little attention. It was not until the subsequent technological advances solved a series of problems such as the sealing of the cycle under high temperature and high pressure that the S-CO2 power cycle technology was once again valued, and the academic and engineering communities invested a lot of energy in it. To date, the S-CO2 power cycle technology has been widely studied in many thermal energy utilization fields such as nuclear energy, solar energy, and waste heat recovery.

[0004] In recent years, many researchers have The S-CO2 power cycle technology was comprehensively studied by the analytical method. Sharma et al. completed the energy analysis and The results showed that the overall efficiency of the integrated system increased by 10% and the net power increased by 25%. Abdelghafar et al. comprehensively compared the energy, economy, Economic performance, research shows three-cycle system The efficiency is the highest (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. The analysis results show that the S-CO2 heat exchange equipment has less This is because there is no phase change in the heat transfer process of S-CO2, and there is a good temperature match. At the same time, the study also found that the recompression structure of the S-CO2 power cycle can improve the thermal matching of the system, thereby reducing the system Jiang et al. integrated the S-CO2 power cycle and the ejector refrigeration cycle, and compared with the single S-CO2 cycle The efficiency can be increased by 2.65%, the main The losses are concentrated in the regenerator.

[0005] The analysis method has become a mature and widely used system performance analysis tool, which can calculate the loss, Efficiency, proposes improvement directions for the cycle process, but cannot quantify the improvement potential of the equipment. The emergence of analytical methods fills this gap, providing more detailed and in-depth Loss analysis can quantify the improvement potential of equipment and systems, and can simultaneously reveal the size, location and influencing factors of energy flow quality loss in the system. The analysis shows that the irreversible loss of a component is not only determined by its own limited thermodynamic properties, but also by the effects of other components. The losses are further decomposed according to certain relationships, and realistic factors such as insufficient technical level and economic constraints are taken into consideration, making the analysis results more valuable for practical engineering applications and conducive to the transformation of theoretical results into engineering practice. The initial analysis object of the analytical method was mainly the refrigeration cycle. Due to its outstanding advantages, it has gradually been developed into a tool for evaluating other energy conversion systems, such as the ORC system. The analytical method is applied to the S-CO2 power cycle system, so the S-CO2 power cycle is advanced. The analysis deserves extensive and in-depth study.

[0006] In view of the above analysis, the technical problems that need to be solved in the prior art are: The analytical method is applied to the S-CO2 power cycle system. Summary of the invention

[0007] In view of the problems existing in the prior art, the present invention provides a S-CO 2 Twin Turbine Power Generation System Advanced Analysis methods and systems.

[0008] The present invention is achieved by: a S-CO 2 Twin Turbine Power Generation System Advanced Analytical methods, including:

[0009] S1, using the process simulation software Aspen HYSYS to build a simulation model of the S-CO2 twin-turbine power cycle;

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

[0011] S3, complete advanced Analyze and analyze the room for improvement in system and component performance;

[0012] S4, explore the role of irreversible losses within the system;

[0013] S5, propose the priority order for component improvements.

[0014] Furthermore, in order to simplify the modeling calculation of the circulatory system, the following assumptions are introduced:

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

[0016] ②S-CO 2 There is no leakage of working fluid during the circulation process;

[0017] ③ Ignore the pressure loss and heat energy loss of the system pipeline;

[0018] ④ Not considering S-CO 2 Working fluid chemistry kinetic energy Potential Energy Consider only its physical

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

[0020]

[0021] S-CO 2 System net output power W net for:

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

[0023] Where, the power turbine output power W PT , core turbine output power W CT , compressor power consumption W comp Calculated by the following formulas:

[0024]

[0025] In the formula, Indicates S-CO 2 Mass flow rate of working fluid, kg / s; F sr is the turbine split ratio, defined as the S-CO flowing through the power turbine 2 Mass flow and circulation S-CO 2 The ratio of the total mass flow rate; h is Figure 1where is the specific enthalpy of the corresponding stream, 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 Q cool , Regenerator load Q recu Calculated by the following formulas:

[0027]

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

[0029] Further, based on advanced Analysis method, the irreversible loss in component k can be divided into the part that is not affected by other components and the part that is affected by other components, that is, the endogenous Losses and exogenous sources loss:

[0030]

[0031] In the formula, Represent the endogenous source of component k Loss rate, external Loss rate, kW.

[0032] Referring to the thermodynamic cycle method, six groups of primary mixed cycles were constructed for the six main components to calculate Then, 15 secondary mixing cycles were constructed with the six main components in groups of two to analyze the relationship between the irreversible losses of the components:

[0033]

[0034] In the formula, The external source exists when component k is irreversibly affected by component r (component r and component k are two different components). Loss rate, kW; is the secondary mixing cycle consisting of component k and component r. Loss rate, kW; is exogenous to component k Loss rate, kW.

[0035] The irreversible loss in component k can also be divided into the part that cannot be eliminated due to objective conditions and the part that can be overcome by improving the component or choosing a more suitable component, that is, the endogenous Losses and exogenous sources loss:

[0036]

[0037] In the formula, and Represents the inevitable Loss rate and avoidable Loss rate, kW.

[0038] Further, it is inevitable Loss Rate It can be calculated by the following formula:

[0039]

[0040] In the formula, is the unavoidability index of component k.

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

[0042]

[0043] In the formula, are the unavoidable endogenous Loss rate, avoidable endogenous Loss rate, unavoidable external sources Loss rate, avoidable external sources Loss rate, kW.

[0044] Another object of the present invention is to provide a method for realizing the S-CO 2 Twin Turbine Power Generation System Advanced S-CO of analytical method 2 Twin Turbine Power Generation System Advanced Analytical systems, including:

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

[0046] conventional Analysis module, routine testing of S-CO2 twin-turbine power generation system analyze;

[0047] advanced Analysis module, completes advanced Analyze and analyze the room for improvement in system and component performance;

[0048] Irreversible loss action relationship module, to explore the action relationship of irreversible losses within the system;

[0049] The modules are proposed in order of priority and the priority order of component improvements is proposed.

[0050] Another object of the present invention is to provide a computer device, the computer device comprising a memory and a processor, the memory storing a computer program, and when the computer program is executed by the processor, the processor executes the S-CO 2 Twin Turbine Power Generation System Advanced Steps of the analytical 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, enables the processor to execute the S-CO 2 Twin Turbine Power Generation System Advanced Steps of the analytical method.

[0052] Another object of the present invention is to provide an information data processing terminal, the information data processing terminal includes the S-CO 2 Twin Turbine Power Generation System Advanced Analytical system.

[0053] In combination with the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solutions to be protected by the present invention are as follows:

[0054] First, the present invention constructs a S-CO2 dual-turbine power generation system, uses Aspen HYSYS software as a tool to simulate the system operation, calls the REFPROP database for physical property calculation, and performs advanced system Analyze the room for improvement of system performance, explore the role of irreversible losses within the system, discuss the priority of component improvements, and discuss the differences with conventional Comparison of analysis results. The research conclusions are as follows:

[0055] 1) General The analysis results show that the heater and regenerator in the system are The most damaged component, the heater The loss rate is 569.17kW, the regenerator The loss rate is 556.67kW, and the two are in the total system The losses accounted for 38.3% and 37.5% of the system 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 about 22.3% room for improvement in efficiency, but under objective conditions the actual room for improvement is about 11.8%.

[0057] 3) External sources of system components The loss rate is 434.713kW, which is the total power consumption of the system. The loss accounts for 29.3%, which reveals that there is an important connection between the irreversibility of key components. Among them, the components with stronger irreversibility are power turbines, core turbines and regenerators. Improving these components can not only reduce their own loss, and can also reduce the external loss.

[0058] 4) Advanced The analysis indicates that the priority should be to improve the heater and the regenerator, both of which can avoid endogenous The loss rate is the highest, 159.072kW and 117.223kW respectively, followed by the power turbine, compressor, core turbine, and the cooler is at the bottom.

[0059] 5) General Analysis shows that the cooler The loss rate is 168.054kW, ranking third, while the advanced The analysis shows that the endogenous part that can be avoided is only 11.925kW, and its improvement importance drops directly to the bottom, resulting in an increase in the improvement priority of the power turbine, compressor, and core turbine. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 The S-CO provided in the embodiment of the present invention 2 Schematic diagram of the twin-turbine Brayton cycle system flow chart;

[0061] Figure 2 The S-CO provided in the embodiment of the present invention 2 Schematic diagram of the simulation interface of the twin-turbine power generation system in Aspen HYSYS;

[0062] Figure 3 The twin-turbo S-CO provided by the embodiment of the present invention 2 The main components of the power generation system Schematic diagram of loss distribution;

[0063] Figure 4 The compressor provided by the embodiment of the present invention is subjected to the external source of the irreversible effect of the components Schematic diagram of loss distribution;

[0064] Figure 5 The power turbine provided by the embodiment of the present invention is subjected to the external source of the irreversible effect of the components Schematic diagram of loss distribution;

[0065] Figure 6 The core turbine provided by the embodiment of the present invention is subjected to the external source of the irreversible effect of the components. Schematic diagram of loss distribution;

[0066] Figure 7 The heater provided by the embodiment of the present invention is subjected to the external source of the irreversible effect of the component Schematic diagram of loss distribution;

[0067] Figure 8 The cooler provided by the embodiment of the present invention is subjected to the external source of the irreversible effect of the components. Schematic diagram of loss distribution;

[0068] Fig. 9 The heat regenerator provided by the embodiment of the present invention is subjected to the external source of the irreversible effect of the components. Schematic diagram of loss distribution;

[0069] Fig.10 The main components of the system provided by the embodiment of the present invention can avoid Loss rate and division of endogenous and exogenous sources Schematic diagram of loss rate distribution;

[0070] Fig.11 It is an advanced embodiment of the present invention. Analytical and general Schematic diagram of component improvement priorities under analysis;

[0071] Fig.12 The S-CO provided in the embodiment of the present invention 2 Twin Turbine Power Generation System Advanced Flow chart of analytical method;

[0072] Fig.13 The S-CO provided in the embodiment of the present invention 2 Twin Turbine Power Generation System Advanced Analysis system structure diagram. DETAILED DESCRIPTION

[0073] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0074] 1 Model establishment

[0075] 1.1S-CO 2 Twin turbine power generation system model

[0076] S-CO 2 The Brayton cycle has the advantages of high efficiency, compact layout, and multiple application scenarios. The present invention constructs an S-CO 2 The twin-turbine power generation system is characterized by a simple heat recovery S-CO 2 Based on the Brayton cycle, the CO at the heater outlet 2 The working fluid is split and the CO 2 The working fluid is distributed to two turbines, expanded and worked, and then converged and transported to the next device. The system process is as follows: Figure 1 shown.

[0077] S-CO 2 The working fluid flows through the compressor (1-2) and is pressurized from the near-critical point to the far-critical point, then passes through the regenerator (2-3) to receive the waste heat of the exhaust gas from the turbine and is heated, and flows through the heater (3-4) to recover the waste heat of the high-temperature flue gas (7-8) and further heat it. 2 The working fluid is split into two streams 4P and 4C at point 4, and respectively transported to the power turbine (4P-5P) and the core turbine (4C-5C) 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 then further cooled to near the 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 Cycle Simulation and Verification

[0080] In order to simplify the modeling calculation of the circulatory system, the following assumptions are introduced:

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

[0082] ②S-CO 2 There is no leakage of working fluid during the circulation process;

[0083] ③ Ignore the pressure loss and heat energy loss of the system pipeline;

[0084] ④ Not considering S-CO 2 Working fluid chemistry kinetic energy Potential Energy Consider only its physical

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

[0086]

[0087] S-CO 2 System net output power W net for:

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

[0089] Where, the power turbine output power W PT , core turbine output power W CT , compressor power consumption W comp Calculated by the following formulas:

[0090]

[0091] In the formula, Indicates S-CO 2 Mass flow rate of working fluid, kg / s; F sr is the turbine split ratio, defined as the S-CO flowing through the power turbine 2 Mass flow and circulation S-CO 2 The ratio of the total mass flow rate; h is Figure 1 where is the specific enthalpy of the corresponding stream, 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 by the following formulas:

[0093]

[0094]

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

[0096] The present invention uses Aspen HYSYS software to construct S-CO 2 The twin-turbine power generation system is simulated, such as Figure 2 As shown. 2 The physical properties of the working fluid in the supercritical state are quite special, so it is particularly important to choose an appropriate method to calculate the physical properties. Therefore, the Refprop state equation is selected as the simulation physical property calculation method, which has been verified to provide good accuracy.

[0097] The comparison of basic cycle parameters and 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, indicating that the results calculated by the simulation model are consistent with the test results, the error is within the acceptable range, and the reliability of the simulation model used in the study is good.

[0098] Table 1 S-CO 2 Basic parameters of twin turbine power generation system

[0099]

[0100] Table 2 Cycle simulation calculation results verification

[0101]

[0102] 1.2.2 General Analytical Model

[0103] To distinguish high Analysis, here we will use the commonly used Conventional Analytical model, this analytical model is mainly based on Balance equations are used to quantify the irreversible losses of the system as a whole and each component of the system, and each state point The value can be calculated by the following formula:

[0104]

[0105] In the formula, the subscript i represents Figure 1 The state points 1-10 in , the subscript 0 represents the 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, Represents the input of component k Valid input Loss, kW.

[0109] For the system as a whole, Balanced equations and The efficiency can be expressed by the following formula:

[0110]

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

[0112] Conventional construction of each component level system The analysis and calculation model is shown in Table 3.

[0113] Table 3 Components and overall system Computational model

[0114]

[0115] 1.2.3 Advanced Analytical Model

[0116] Based on advanced Analysis method, the irreversible loss in component k can be divided into the part that is not affected by other components and the part that is affected by other components, that is, the endogenous Losses and exogenous sources loss:

[0117]

[0118] In the formula, Represent the endogenous source of component k Loss rate, external Loss rate, kW.

[0119] The present invention refers to the thermodynamic cycle method and constructs 6 groups of primary mixed cycles for the 6 main components to calculate Then, 15 secondary mixing cycles were constructed with the six main components in groups of two to analyze the relationship between the irreversible losses of the components:

[0120]

[0121] In the formula, The external source exists when component k is irreversibly affected by component r (component r and component k are two different components). Loss rate, kW; is the secondary mixing cycle consisting of component k and component r. Loss rate, kW; is exogenous to component k Loss rate, kW.

[0122] The irreversible loss in component k can also be divided into the part that cannot be eliminated due to objective conditions and the part that can be overcome by improving the component or choosing a more suitable component, that is, the endogenous Losses and exogenous sources loss:

[0123]

[0124] In the formula, and Represents the inevitable Loss rate and avoidable Loss rate, kW.

[0125] Inevitable Loss Rate It can be calculated by the following formula:

[0126]

[0127] In the formula, is the unavoidability 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:

[0129]

[0130]

[0131] In the formula, are the unavoidable endogenous Loss rate, avoidable endogenous Loss rate, unavoidable external sources Loss rate, avoidable external sources Loss rate, kW.

[0132] 2 General analyze

[0133] conventional Analysis is used to quantify the irreversible losses of the main components in the system, which is an important part of measuring the room for improvement of the system. Loss rate realization, compressor, power turbine, core turbine, heater, condenser, regenerator Loss composition ratio Figure 3 As shown, the heater and regenerator occupy the system The majority of the losses are in the cooler, followed by the power turbine, compressor, and core turbine, while smaller proportions are in the power turbine, compressor, and core turbine.

[0134] In the twin-turbo S-CO 2 Heaters and regenerators in power generation systems Loss is the main source of system irreversibility. Under the design operating conditions, the heater Loss Rate 569.17kW, regenerator Loss Rate is 556.67kW, and the total power of the two systems The losses accounted for 38.3% and 37.5% respectively, and a total of 75.8%, which had a significant impact on the system's total The loss has a decisive influence on the size, which can be attributed to the high heat transfer temperature difference in the heat transfer process. The study found that S-CO 2 The LMTD values ​​of the system's heater and regenerator during heat exchange reached 68.79K and 61.43K respectively, both at a relatively high level.

[0135] Cooler Loss Rate The value is 168.05kW, which is lower than that of the heater and the regenerator. Loss value, in the system total The loss accounts for only 11.3%, which is a relatively low proportion. This is due to the fact that the temperature of the cooling water is closer to that of CO 2 The critical temperature of the working fluid, the heat exchange temperature difference of the cooler is small, and the data shows that its LMTD value is only 17.14K, which is at a low level in the three heat exchange processes of the system. Lower losses than heaters and regenerators The main cause of loss.

[0136] Twin Turbo S-CO 2 Power equipment in power generation system The losses accounted for only 12.9% of the total, and the compressor Loss Rate 69.28kW, power turbine Loss Rate 76.84kW, core turbine Loss Rate The total power of the three is 44.84kW. The losses accounted for 4.7%, 5.2% and 3.0% respectively, which are all at extremely low levels, reflecting the good performance of the system power equipment, which can be shown in the isentropic efficiency of about 80%. The total loss rate is 121.68kW, accounting for 8.2% of the system, which is higher than the compressor but still lower than the cooler.

[0137] In summary, by quantifying and comparing the irreversible losses of the main components of the system, it can be seen that The losses are concentrated in the heater and regenerator, followed by the cooler, while the losses in the compressor, power turbine, core turbine, The loss is minimal for the system. This also means that when planning to improve the system components, the heater and regenerator should be considered as the highest priority components, and their improvement can bring greater benefits to the system, followed by the cooler, and finally the power turbine, compressor, and core turbine.

[0138] 3Advanced analyze

[0139] 3.1 System Performance Analysis

[0140] In Advanced In the analysis, operating conditions are divided into three types. The first is the actual conditions of the main components when the system is running under realistic conditions. The second is the ideal conditions of the system components after ignoring all process losses. The third is the unavoidable conditions that can make the components achieve the best performance by using existing technologies. Among them, the ideal conditions and unavoidable conditions are set based on actual conditions. Table 4 lists the key parameters of the main components under actual conditions, ideal conditions, and unavoidable conditions. The pinch point temperature difference and pressure drop are used to represent the parameters that affect the losses of the three heat exchangers, heater, cooler, and regenerator, and the isentropic efficiency is used to represent the parameters that affect the losses of the turbine and compressor.

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

[0142]

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

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

[0145]

[0146] Based on the actual cycle, referring to the setting of ideal conditions and unavoidable conditions, the ideal cycle and the unavoidable cycle are 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 conditions

[0148]

[0149] Based on the above settings, the net output power of the ideal cycle and the unavoidable cycle is equal to the net output power of the actual cycle, so as to ensure the consistency of the system in scale. Comparing the operating data of the system under the three conditions, under the condition of the same net profit, the actual cycle requires a larger flue gas flow and cooling water flow to ensure the profit of the system, while the ideal cycle and the unavoidable cycle require lower flow rates, and the flow rate required for the ideal cycle is less than that required for the unavoidable cycle. This means that the closer the system is to the ideal state, the higher the operating efficiency, and the less investment is required under certain output conditions. The system under ideal conditions The efficiency reached 65.50%, which set an upper limit for the improvement of system performance, compared with 43.17% under actual conditions. efficiency, the system still has about 22% room for efficiency improvement. Under unavoidable conditions, the system The efficiency can reach 54.93%, which represents the maximum efficiency that the system can achieve through technical means, and is the upper limit of the system performance that can be improved by combining the actual conditions. Furthermore, by comparing the system under ideal conditions and unavoidable conditions Efficiency, we know that there is 10.57% The efficiency is restricted by technical barriers and cannot be improved, compared with 43.17% under actual conditions. Efficiency, system The room for improving efficiency through technical means is close to 12%.

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

[0151]

[0152] 3.2 Endogenous and exogenous Loss Analysis

[0153] Use advanced The analytical method will exist in the system The loss is divided into endogenous and exogenous parts, and the results are shown in Table 7. Loss refers to the loss caused by the performance defects of a component itself. Loss is the loss caused by the performance defects of other parts and other factors. Source of loss.

[0154] In S-CO 2 In a twin-turbine power generation system, the internal source of the regenerator Loss Rate The power output is 469.387kW, which is higher than the internal power output of other components. loss rate, and its exogenous Loss Rate It is only 87.283kW, which shows that its performance is not easily affected by other components and is mainly determined by the internal factors of this component. Loss Rate Slightly higher than the total heat exchanger Loss Rate But its endogenous Loss Rate But lower than 395.654kW, which shows that the irreversibility of the heater is more affected by the other inefficient components. Loss Rate It is also the highest among the system components, at 173.514kW. Loss Rate Only 54.650kW, its external source Loss Rate It reaches 113.404kW, which is all the components The only part of the loss that is higher than the internal source part is the exogenous part, which reflects that the cooler is the component most seriously affected by the external factors of the component itself, and its interaction relationship deserves further analysis.

[0155] Table 7 Internal and external sources of main components of the system Loss Rate

[0156]

[0157] Due to the power equipment of the system Low loss rate, internal source of compressor, power turbine and core turbine Loss rate and exogenous The loss rate is also low, among which the compressor Endogenous part of the loss Slightly higher than the exogenous part The two turbines Endogenous part of the loss Both are several times higher than the exogenous part Indicates turbine The loss is mainly determined by its own performance deficiencies, and the compressor is also subject to strong constraints from other factors in addition to its own factors.

[0158] At the system level, external The sum of the loss rates The total power of the system is 434.713kW. Loss Rate This indicates that there is a non-negligible relationship between the irreversibility of key components. Loss Rate In the system total The loss accounts for 11.7%, the highest among all components. Therefore, in order to reduce the larger To reduce the loss, it is necessary not only to improve the heater itself, but also to reduce the impact of other components on the irreversible loss of the heater.

[0159] 3.3 Inevitable and avoidable Loss Analysis

[0160] Inevitable Losses are the part that cannot be reduced due to objective factors such as technology and economy. The loss is the part that can be reduced by appropriate technical means, which represents the degree of improvement of the component. Table 8 lists the S-CO 2 The inevitability of a twin-turbo power generation system Loss Rate and avoidable Loss Rate The numerical size of .

[0161] Table 8 Unavoidable and avoidable problems of main components of the system Loss Rate

[0162]

[0163] The system After the losses are divided according to the unavoidable conditions, the unavoidable Loss Rate Up to 417.649kW, in total inevitable The proportion of the loss rate is as high as 45.9%, which is an absolute large share. Although the heat capacity difference between the high-pressure side and the low-pressure side of the regenerator naturally decreases during the transition from actual conditions to unavoidable conditions, the reduction is small. The effect of reducing the loss is very limited. This means that even after the regenerator is improved, there are still a lot of Losses cannot be eliminated, they can be avoided Loss Rate Only 139.021kW, accounting for only 139.021kW of the total Loss Rate This reveals that the effect of reducing the irreversible loss by improving the regenerator is poor, and more consideration should be given to changing the structure or design parameters of the cycle.

[0164] Similar to the regenerator case, the heater and cooler The room for reducing losses is also relatively limited, which is mainly reflected in the inevitable Loss Rate 338.709 kW, 105.709kW are higher than their respective avoidable The loss and the improvement space are about 40%.

[0165] In contrast, S-CO 2 Power equipment in twin turbine power generation system A large part of the losses can be reduced and avoided Loss Rate Each The loss rate was 78.0%, 69.0% and 79.1%, which shows that the improvement of these power equipment is less restricted by technology and the feasibility of reducing its irreversible loss is higher. From the actual cycle to the irreversible cycle, the turbine isentropic efficiency is increased to 95.00%, CO 2 The entropy increase of the working fluid expansion process was reduced by 63.8% and 73.8% respectively, which can effectively increase the enthalpy difference between the inlet and outlet, so that the improved turbine can provide a larger output power for the system, and the power consumption of the compressor will also be smaller. The loss rate of each power device is several times lower than that of the heater and regenerator, so its improvement priority is still under discussion.

[0166] At the system level, it is inevitable Loss Rate 910.505kW, accounting for 61.3% of the share. This result shows that in the conventional It is necessary to consider the limitations of real technology based on the analysis. Analysis can improve the reliability of component improvement plans.

[0167] 3.4 Correlation analysis of irreversible losses of key components

[0168] Considering S-CO 2 There is a strong correlation between the components in the operation of the twin-turbine power generation system. It is necessary to further discuss the interaction between the irreversible losses of the components and The loss rate is divided according to the affected components.

[0169] Compressor external source The distribution of losses is as follows Figure 4 As shown, the compressor's external Loss Rate It accounts for 59.9%, which shows that the compressor is greatly affected by the internal connection of other components. Secondly, the turbine has a greater effect on the compressor among the components, accounting for a total of 26.6%, of which the power turbine 17.1%, core turbines In contrast, the irreversible losses of various heat exchange equipment have a great impact on the compressor. The loss effect is relatively weak, the heater, regenerator and cooler have some effect They only accounted for 6.4%, 5.1%, and 2.1% respectively. This shows that by reducing the external The loss-prone way to improve the compressor mainly relies on improving the system structure or improving the turbine performance.

[0170] like Figure 5 As shown, the power turbine is external The losses were also greatly affected by the exogenous part. The proportion reached 42.0%. Similar to compressors, power turbines The losses are mainly caused by the power equipment, among which the core turbine plays the most significant role. Accounting for 29.2%, followed by the compressor function part Accounting for 16.4%. Among the heat exchange equipment, only the heater plays a prominent role. Accounting for 11.8%, while the role of coolers and regenerators is partly It accounts for only 0.2% and 0.4% and can be ignored.

[0171] from Figure 6 It can be seen that the core turbine external source The loss distribution is roughly the same as that of the power turbine, but the power turbine has a greater effect on the core turbine. Accounting for 40.0%, exceeding exogenous Loss Rate That is, improving both turbines in a twin-turbo system will benefit both external sources. Reduction of losses.

[0172] Heater external source The distribution of losses is as follows Figure 7 As shown, the heater is external The part of the loss affected by the regenerator It accounts for 36.3%, indicating that the regenerator is the component with the greatest impact on it. Improving the regenerator is the key to reducing the external source of the heater. Secondly, the turbine also has a strong influence on the heater. The total share is 32.9%. In addition, The proportion of 20.3% also shows that the heater is external The loss will be affected to some extent by the exogenous part. It only accounts for 1.3%, which shows that the cooler has little effect on the heater.

[0173] like Figure 8 As shown, unlike the heater, the cooler is external The loss is more affected by the exogenous part. Accounting for 56.4%, indicating that the external source of cooling is reduced The loss needs to be reduced by improving the structure of the cycle or optimizing the operating parameters of the cycle. Secondly, the regenerator has the greatest impact on the cooler at the component level. Accounting for 26.9%, improving the heat exchanger can also reduce the cooling The other components have a weak effect on the cooler, and the external sources they act on The loss ratio is between 2.7% and 6.4%. Combined with the fact that the aforementioned components are 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] Regenerator external source The distribution of losses is as follows Fig. 9 As shown, the part where the power turbine acts The proportion is as high as 39.1%, and the effect on the recuperator is the strongest. At the same time, the core turbine part It also accounts for 21.7%, the total turbine effect in the heat exchanger external source The losses accounted for 60.8% in total, indicating that improvements to the turbine would be particularly beneficial to the recuperator. Unlike the larger effect 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. and account for only 0.9% and 4.2% respectively. Losses also play a role to a certain extent. The proportion is 27.7%, but its value is negative, which means that only improving the circulation structure does not help the external source of the regenerator. In addition to reducing losses, we should also consider improving other components.

[0175] In summary, when improving the power turbine, core turbine and regenerator, not only can the improved components themselves be reduced, losses, and is expected to simultaneously reduce the large external sources it generates for other components. Loss. The exogenous part is external to each component. The losses have a considerable impact, so improvements to the cycle design also need to be considered.

[0176] 3.5 Component Improvement Priority Analysis

[0177] In order to propose a more reliable component improvement plan to reduce the irreversible loss in the system and thus improve the system's operating performance, advanced The analytical model further separates the inevitable and avoidable The loss rate was further decomposed into inevitable internal sources, inevitable 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] Since the inevitable part is the system The loss is inherent and cannot be eliminated by technical means such as improving components. Losses are usually not the focus of attention. Improvements to components should start with feasibility. Loss rate and avoidable internal and external sources after classification The loss rate distribution is as follows Fig.10 shown.

[0181] It can be seen that the heater is the largest avoidable The loss rate of parts accounts for 40.1%, which can be avoided The internal source accounts for 69.0% of the loss rate, and the external source accounts for 31.0%. Although there are more external sources, the heater itself The loss rate is numerically higher than other components, which can avoid endogenous Loss Rate It is obviously the highest among all components, which indicates that the heater should be considered as a priority component for improvement in view of feasibility and benefits.

[0182] For the regenerator, the above total Loss Rate Only slightly lower than the heater But the senior The analysis results show that it can avoid some Significantly lower than the heater In the system can always avoid The losses only account for 24.2%, so although there is 84.3% of the endogenous part, Still lower than the heater This means that senior The analysis indicated that the regenerator should also be given a lower priority than the heater for improvement.

[0183] In terms of power equipment, the power turbine, core turbine, and compressor can be avoided. Loss Rate Total avoidable The loss rate is 9.2%, 6.2%, and 9.4%, and the compressor ratio is slightly higher than that of the power turbine and the core turbine, but due to the external part of the two turbines In its own avoidable The losses accounted for only 23.2% and 27.0% respectively, which is lower than that of compressors. 44.2% of the total The losses are sorted from large to small, as follows: Improvements to the power turbine take priority over the compressor and core turbine.

[0184] advanced Analysis shows avoidable internal sources of cooling Loss Rate The lowest proportion in the system is due to its The avoidable part of the loss is greatly affected by factors other than the components themselves. The proportion is as high as 80.9%, and the endogenous part Only 19.1% is left, which means that improving the cooler of this system is essential to reduce its The effect of loss is small, combined with the aforementioned irreversibility of the cooler, the external The effect of losses is also small, so it can be concluded that the benefits of cooler improvements are poor and its priority should be ranked last among the components.

[0185] In summary, after considering the feasibility and benefits of component improvements, S-CO 2 The components that should be improved first in the twin-turbine power generation system are the heater and recuperator, followed by the power turbine, compressor, and core turbine, and the cooler has the lowest priority.

[0186] 3.6 General Analytical and Advanced Comparative discussion of analysis results

[0187] After advanced After analysis, it can be found that the results are consistent with the conventional The analysis results vary, mainly in the order of priority for component improvement. Fig.11 The comparison of the two analysis results is shown, where the red area in the upper half represents the high-level The gray area in the lower half represents the results of the analysis. As a result of the analysis, improvement priorities have been identified.

[0188] advanced Analytical and general The analysis has identified heaters and regenerators as the highest priority components for improvement, but the degree of improvement has changed to some extent. loss Proportion and avoidable endogenous loss The proportions are respectively Analytical and Advanced Analyze the parameters that quantify the importance of component improvements, and observe the After analysis, the importance of heater improvement increased slightly (38.3% → 41.3%), while the importance of regenerator improvement decreased (37.5% → 30.5%). This is mainly due to the fact that the regenerator The inevitable loss is too much, which is limited by the actual technology. The importance of both increased by two times in the analysis, with power turbines rising from fourth to third priority (5.2% → 10.6%) and core turbines rising from sixth to fifth priority (3.0% → 6.7%), thanks to the The avoidable internal source part accounts for a high proportion of the loss, and the space and feasibility of the component itself are relatively high. The importance of compressor improvement has also increased from fifth to fourth (4.7%→7.8%), but its improvement is not as high as that of turbine, which is limited by its The component with the largest change in improvement importance is the cooler, which dropped from the third priority to the last (11.3% → 3.1%). The avoidable part of the loss is relatively small. On the other hand, the endogenous part is less than 20%, which is the component in the system most affected by factors other than the component itself. To reduce its loss, we should improve the regenerator or optimize 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, providing more reference information for further improving the system, making the results more reliable, and helping engineers deepen their understanding of the irreversible losses of the system.

[0190] like Fig.12 As shown, the S-CO provided in the embodiment of the present invention 2 Twin Turbine Power Generation System Advanced The analysis method is characterized by comprising:

[0191] S1, using the process simulation software Aspen HYSYS to build a simulation model of the S-CO2 twin-turbine power cycle;

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

[0193] S3, complete advanced Analyze and analyze the room for improvement in system and component performance;

[0194] S4, explore the role of irreversible losses within the system;

[0195] S5, propose the priority order for component improvements.

[0196] like Fig.13 As shown, the S-CO provided in the embodiment of the present invention 2 Twin Turbine Power Generation System Advanced 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 twin-turbine power cycle;

[0198] conventional Analysis module, routine testing of S-CO2 twin-turbine power generation system analyze;

[0199] advanced Analysis module, completes advanced Analyze and analyze the room for improvement in system and component performance;

[0200] Irreversible loss action relationship module, to explore the action relationship of irreversible losses within the system;

[0201] The modules are proposed in order of priority and the priority order of component improvements is proposed.

[0202] An application embodiment of the present invention provides a computer device, the computer device includes a memory and a processor, the memory stores a computer program, and when the computer program is executed by the processor, the processor executes S-CO 2 Twin Turbine Power Generation System Advanced Steps of the analytical method.

[0203] The application embodiment of the present invention provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the processor executes S-CO 2 Twin Turbine Power Generation System Advanced Steps of the analytical method.

[0204] The application embodiment of the present invention provides an information data processing terminal, the information data processing terminal includes an S-CO 2 Twin Turbine Power Generation System Advanced Analytical system.

[0205] It should be noted that the embodiments of the present invention can be implemented by hardware, software, or a combination of software and hardware. The hardware part can be implemented using dedicated logic; the software part can be stored in a memory and executed by an appropriate instruction execution system, such as a microprocessor or dedicated design hardware. It can be understood by a person of ordinary skill in the art that the above-mentioned devices and methods can be implemented using computer executable instructions and / or contained in a processor control code, such as a carrier medium such as a disk, CD or DVD-ROM, a programmable memory such as a read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. Such code is provided on the carrier medium. The device and its modules of the present invention can be implemented by hardware circuits such as very large-scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, etc., or programmable hardware devices such as field programmable gate arrays, programmable logic devices, etc., can also be implemented by software executed by various types of processors, and can also be implemented by a combination of the above-mentioned hardware circuits and software, such as firmware.

[0206] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered by the protection scope of the present invention.

Claims

1. A S-CO2 dual turbine power generation system with advanced The analytical method is characterized in that include: S1, using the process simulation software Aspen HYSYS to build a simulation model of the S-CO2 twin-turbine power cycle; S2, routine testing of the S-CO2 twin-turbine power generation system analyze; S3, complete advanced Analyze and analyze the room for improvement in system and component performance; S4, explore the role of irreversible losses within the system; S5, propose the priority order for component improvements.

2. The S-CO2 twin-turbine power generation system according to claim 1 The analytical method is characterized in that In order to simplify the modeling calculation of the circulatory system, the following assumptions are introduced: ①The circulatory system maintains steady-state operation; ②S-CO2 working fluid has no leakage during the circulation process; ③ Ignore the pressure loss and heat energy loss of the system pipeline; ④ The chemical properties of S-CO2 are not considered. kinetic energy Potential Energy Consider only its physical 3. The S-CO2 dual turbine power generation system according to claim 1 The analytical method is characterized in that According to the first law of thermodynamics, the heat transfer process in the circulating heat exchanger and the energy conversion process of the power equipment satisfy the energy conservation equation: S-CO2 system net output power W net for: IN net =In PT +W CT -IN comp (2) Where, the power turbine output power W PT , core turbine output power W CT , compressor power consumption W comp Calculated by the following formulas: In the formula, Indicates the mass flow rate of S-CO2 working fluid, kg / s; F sr is the turbine split ratio, defined as the ratio of the S-CO2 mass flow rate flowing through the power turbine to the total circulating S-CO2 mass flow rate; h is the specific enthalpy of the corresponding stream in Figure 1, kJ / kg; the subscripts PT, CT, and comp represent the power turbine, core turbine, and compressor in the system, respectively; Heater load Q heat , Cooler load Q cool , Regenerator load Q recu Calculated by the following formulas: Wherein, the subscripts heat, cool, and recu represent the heater, cooler, and regenerator in the system, respectively.

4. The S-CO2 twin-turbine power generation system according to claim 1 The analytical method is characterized in that Based on advanced Analysis method, the irreversible loss in component k can be divided into the part that is not affected by other components and the part that is affected by other components, that is, the endogenous Losses and exogenous sources loss: In the formula, Represent the endogenous source of component k Loss rate, external Loss rate, kW; Referring to the thermodynamic cycle method, six groups of primary mixed cycles were constructed for the six main components to calculate Then, 15 secondary mixing cycles were constructed with the six main components in groups of two to analyze the relationship between the irreversible losses of the components: In the formula, The external source exists when component k is irreversibly affected by component r (component r and component k are two different components). Loss rate, kW; is the value of component k in the two-stage mixing cycle consisting of component k and component r. Loss rate, kW; is exogenous to component k Loss rate, kW; The irreversible loss in component k can also be divided into the part that cannot be eliminated due to objective conditions and the part that can be overcome by improving the component or choosing a more suitable component, that is, the endogenous Losses and exogenous sources loss: In the formula, and Represents the inevitable Loss rate and avoidable Loss rate, kW.

5. The S-CO2 dual turbine power generation system according to claim 1 The analytical method is characterized in that Inevitable Loss Rate It can be calculated by the following formula: In the formula, is the unavoidability index of component k.

6. The S-CO2 dual turbine power generation system according to claim 1 The analytical method is characterized in that Components The loss can be divided into four parts, and their relationship can be expressed as: In the formula, are the unavoidable endogenous Loss rate, avoidable endogenous Loss rate, unavoidable external sources Loss rate, avoidable external sources Loss rate, kW.

7. A method for realizing the S-CO2 dual-turbine power generation system according to any one of claims 1 to 7 Analytical Methods for S-CO2 Twin Turbine Power Generation System Advanced An analysis system, characterized in that include: The simulation model building module uses the process simulation software Aspen HYSYS to build a simulation model of the S-CO2 twin-turbine power cycle; conventional Analysis module, routine testing of S-CO2 twin-turbine power generation system analyze; advanced Analysis module, completes advanced Analyze and analyze the room for improvement in system and component performance; Irreversible loss action relationship module, which analyzes the action relationship of irreversible losses within the system; The modules are proposed in order of priority and the priority order of component improvements is proposed.

8. A computer device, comprising a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the advanced S-CO2 twin-turbine power generation system according to any one of claims 1 to 7. Steps of the analytical method.

9. A computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to execute the advanced S-CO2 dual-turbine power generation system according to any one of claims 1 to 7. Steps of the analytical method.

10. An information data processing terminal, comprising the S-CO2 dual turbine power generation system advanced Analytical system.

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