Method, system and device for calculating thermal economy index of steam turbine unit and storage medium

Abstract

The application discloses a steam turbine unit thermal economy index calculation method, system, equipment and a storage medium, and belongs to the technical field of steam turbine generator unit thermal system performance monitoring and energy efficiency evaluation. First, original operation thermal parameters of the steam turbine unit are acquired, including each shaft seal steam leakage fraction and specific enthalpy. According to the steam-water flow of the regenerative system, a heat balance equation of each regenerative device is established, considering the device efficiency, shaft seal steam leakage and the influence of the step-by-step gravity flow of the drain water. The steam extraction, drain water and condensing fraction of each stage are obtained by step-by-step solving. The work deficiency coefficient of the steam extraction and shaft seal steam leakage of each stage is calculated, and then the new steam consumption is obtained. The actual output power of the unit is calculated, and is closed-loop checked with the measured power generation power. When the error exceeds the preset range, the parameters are corrected and the calculation is repeated until the requirements are met. Finally, the thermal economy index of the unit is calculated based on the checked parameters.

Description

Technical Field

[0001] This invention belongs to the technical field of thermal system performance monitoring and energy efficiency assessment of steam turbine generator sets, specifically involving the calculation method, system, equipment and storage medium for the thermal economic indicators of steam turbine generator sets. Background Technology

[0002] The turbine regenerative system is an important component of thermal power units. By extracting steam from each stage of the turbine to heat the feedwater or condensate, the thermal cycle efficiency of the unit can be significantly improved. Accurately calculating thermal economic indicators such as the extraction steam share, condensate share, steam consumption rate, and heat consumption rate at each stage is of great significance for optimizing unit operation, load scheduling, and energy conservation and consumption reduction.

[0003] Currently, simplified empirical formulas or offline heat balance diagrams are often used for estimation in the field, which are difficult to adapt to dynamic changes such as varying operating conditions, coal types, and equipment aging. Existing methods have the following shortcomings: The calculation of steam extraction share is cumbersome and easily overlooks actual factors: In traditional heat balance calculations, the steam extraction share of each stage of heater is usually derived based on the design operating conditions, without fully considering the influence of actual operating parameters such as heater efficiency, shaft seal leakage, and feedwater pump enthalpy rise, resulting in large calculation deviations.

[0004] The coupling between the underwork coefficient and the steam consumption coefficient is complex: the impact of each stage of steam extraction on the work capacity (underwork coefficient) is coupled with the new steam consumption, which requires iterative solution and is difficult for on-site technicians to apply quickly.

[0005] Lack of a systematic closed-loop verification method for the entire regenerative heat chain: Existing methods are mostly limited to a single heater or local thermal balance, lacking a closed-loop verification method for the entire heat balance from the deaerator to the low-pressure heater and then to the condenser, which leads to the accumulation of calculation errors.

[0006] Difficulty in updating thermal economic indicators online: Due to the lack of analytical calculation models based on actual operating parameters (extraction steam pressure, temperature, feedwater temperature, etc.), key indicators such as unit heat rate and steam consumption rate are difficult to reflect equipment status changes in real time, affecting dispatch economy.

[0007] Therefore, there is an urgent need for a real-time calculation method for the thermal economy of steam turbine units that can be based on actual operating parameters, take into account the effects of heater efficiency and shaft seal leakage, and has closed-loop verification capability. Summary of the Invention

[0008] The purpose of this invention is to overcome the problems of complex calculation of extraction steam share, lack of closed-loop verification of the whole system, and difficulty in real-time updating of heat rate in the existing calculation of the thermal economy of steam turbine regenerative systems. The invention proposes a method, system, equipment and storage medium for calculating the thermal economy index of steam turbine units.

[0009] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a method for calculating the thermal economic indicators of a steam turbine unit, comprising the following steps: Obtain the original operating thermodynamic parameters of the steam turbine unit, including the leakage steam ratio and specific enthalpy of each shaft seal; Based on the original operating thermodynamic parameters, heat balance equations are established for each stage of the regenerative equipment according to the steam-water flow of the regenerative system, taking into account the effects of equipment efficiency, shaft seal leakage, and the gradual gravity flow of condensate. The heat balance equations at each level are solved step by step to obtain the extraction steam share, condensate share and condensate steam share at each level. Based on the extraction ratio of each stage and the original operating thermodynamic parameters, the work insufficiency coefficient of each stage of extraction and shaft seal leakage is calculated, and the new steam consumption is calculated based on the work insufficiency coefficient. Based on the new steam consumption, the extraction steam share at each stage, the condensate share, the condensate share, and the original operating thermodynamic parameters, the actual output power of the computer group; A closed-loop verification is performed between the actual output power of the unit and the measured power generation. If the error exceeds the preset range, the original operating thermodynamic parameters are corrected and the above steps are repeated until the error meets the requirements, and the verified calculation parameters are obtained. The thermal economy index of the computer group is based on the verified calculation parameters.

[0010] Furthermore, the regenerative equipment at each stage includes a high-pressure heater, a deaerator, and a low-pressure heater connected in sequence from high to low pressure.

[0011] Furthermore, the order of solving the heat balance equations at each level is as follows: starting from the regenerating equipment with the highest pressure, and solving sequentially along the steam-water flow path of the regenerating system towards the regenerating equipment with the lowest pressure.

[0012] Furthermore, the heat balance equation for each stage of the regenerator uses only the extraction steam ratio of that stage as the unknown quantity, while the condensate ratio of the regenerator with higher pressure in the previous stage is substituted into the heat balance equation of that stage as the known quantity.

[0013] Furthermore, the new fuel consumption is calculated based on the insufficient work coefficient, specifically as follows: The steam consumption under condensing conditions is calculated based on the original operating thermodynamic parameters. The new steam consumption is then calculated by combining the insufficient work coefficient, the extraction steam share of each stage, and the leakage steam share of each shaft seal.

[0014] Furthermore, the closed-loop verification is a comprehensive check of the thermal balance of the fully regenerative system, which corrects the original operating thermodynamic parameters through power comparison and iterative calculation.

[0015] Furthermore, thermal economic indicators include heat rate, steam rate, absolute internal efficiency, and absolute electrical efficiency.

[0016] Secondly, the present invention provides a system for calculating the thermal economic indicators of a steam turbine unit, comprising: The parameter acquisition module is used to acquire the original operating thermodynamic parameters of the steam turbine unit, including the leakage steam ratio and specific enthalpy of each shaft seal; The heat balance equation establishment module is used to establish heat balance equations for each stage of regenerative equipment based on the original operating thermodynamic parameters and in accordance with the steam-water flow of the regenerative system, taking into account the effects of equipment efficiency, shaft seal leakage, and the gradual gravity flow of condensate. The heat balance equation solving module is used to solve the heat balance equations at each level step by step to obtain the extraction steam share, condensate share and condensate share at each level. The new steam consumption calculation module is used to calculate the insufficient work coefficient of each stage of steam extraction and shaft seal leakage based on the proportion of each stage of steam extraction and the original operating thermodynamic parameters, and to calculate the new steam consumption based on the insufficient work coefficient. The actual output power calculation module is used to calculate the actual output power of the computer group based on the new steam consumption, the extraction steam share of each stage, the condensate share, the condensate share, and the original operating thermodynamic parameters. The parameter closed-loop verification module is used to perform closed-loop verification between the actual output power of the unit and the measured power generation. When the error exceeds the preset range, the original operating thermodynamic parameters are corrected and the above steps are repeated until the error meets the requirements, and the verified calculation parameters are obtained. The index calculation module is used to calculate the thermal economy index of the computer group based on the verified calculation parameters.

[0017] Thirdly, the present invention provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement a method for calculating the thermal economic indicators of a steam turbine unit.

[0018] Fourthly, the present invention provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements a method for calculating the thermal economic indicators of a steam turbine unit.

[0019] Compared with the prior art, the present invention has the following beneficial technical effects: The proposed method for calculating the thermal economic indicators of steam turbine units, based on the step-by-step heat balance and power deficiency coefficient analysis of the regenerative system, effectively solves the problems of cumbersome calculation of extraction steam share, large errors, and difficulty in real-time application in existing technologies. A step-by-step heat balance equation is established based on the steam-water flow of the regenerative system, and the single-unknown-factor analytical solution is achieved using the step-by-step gravity flow characteristics of the condensate, eliminating the need for multi-parameter coupled iteration and significantly improving computational efficiency, thus meeting the needs of real-time on-site monitoring. Simultaneously, the method fully considers actual operating factors such as equipment efficiency and shaft seal leakage, avoiding deviations caused by traditional design condition derivations and improving calculation accuracy under varying operating conditions and equipment aging states. By introducing the power deficiency coefficient for analytical calculation of new steam consumption, the complex coupling relationship between extraction steam work capacity and new steam consumption is decoupled, simplifying the calculation process and facilitating rapid application by on-site technicians. Furthermore, a closed-loop power verification mechanism for the entire regenerative system is adopted, correcting calculation parameters through measured power, effectively eliminating the accumulation of errors in local heat balance calculations and ensuring the reliability of steam-water share and thermal economic indicators at each stage. This method can provide accurate data support for unit operation optimization, load scheduling and energy conservation and consumption reduction, and significantly improve the operating economy of thermal power units. Attached Figure Description

[0020] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely schematic to aid in understanding the invention and do not specifically limit the shapes and proportions of the components. In the drawings: Figure 1 This is a flowchart of the method for calculating the thermal economic index of steam turbine units according to the present invention.

[0021] Figure 2 This is a simplified structural diagram of the turbine unit thermal economy index calculation system of the present invention.

[0022] Figure 3 This is an electronic diagram of the method for calculating the thermal economic index of steam turbine units according to the present invention.

[0023] Figure 4 This is a flowchart illustrating the method for calculating the thermal economic indicators of a steam turbine unit in an embodiment of the present invention. Detailed Implementation

[0024] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0025] Example 1 See Figure 1 The calculation method for the thermal economic indicators of steam turbine units includes the following steps: Obtain the original operating thermodynamic parameters of the steam turbine unit, including the leakage steam ratio and specific enthalpy of each shaft seal; Based on the original operating thermodynamic parameters, heat balance equations are established for each stage of the regenerative equipment according to the steam-water flow of the regenerative system, taking into account the effects of equipment efficiency, shaft seal leakage, and the gradual gravity flow of condensate. The heat balance equations at each level are solved step by step to obtain the extraction steam share, condensate share and condensate steam share at each level. Based on the extraction ratio of each stage and the original operating thermodynamic parameters, the work insufficiency coefficient of each stage of extraction and shaft seal leakage is calculated, and the new steam consumption is calculated based on the work insufficiency coefficient. Based on the new steam consumption, the extraction steam share at each stage, the condensate share, the condensate share, and the original operating thermodynamic parameters, the actual output power of the computer group; A closed-loop verification is performed between the actual output power of the unit and the measured power generation. If the error exceeds the preset range, the original operating thermodynamic parameters are corrected and the above steps are repeated until the error meets the requirements, and the verified calculation parameters are obtained. The thermal economy index of the computer group is based on the verified calculation parameters.

[0026] See Figure 4 Specifically, the calculation method for the thermal economic indicators of steam turbine units includes the following steps: 1. Original data and calculation parameters 1.1. Given the enthalpy of the new vapor kJ / kg; extraction enthalpy at each stage kJ / kg; exhaust enthalpy , kJ / kg; enthalpy rise of reheat steam kJ / kg; Known kJ / kg; kJ / kg; kJ / kg; 2.2. The outlet enthalpy of each heater is known. kJ / kg; related hydrophobic enthalpy 'and kJ / kg; 2. Calculate the regenerative extraction coefficient and condensation coefficient. 2.1 High-pressure heater No. 1 (H1): Specific enthalpy at the outlet of the first heater, kJ / kg; The specific enthalpy at the outlet of the second heater, kJ / kg; For heater efficiency; Specific enthalpy of the first-stage extraction steam (kJ / kg); Specific enthalpy at the outlet of the first deaerator, kJ / kg; Determine the extraction volume from the heat balance equation of H1 : (1) (2) Hydrophobicity of H1 : (3) 2.2 High-pressure heater No. 2 (H2): Specific enthalpy at the outlet of the third heater, kJ / kg; Specific enthalpy of the second-stage extraction steam, kJ / kg; First heater hydrophobicity coefficient; Specific enthalpy at the outlet of the second deaerator, kJ / kg; First shaft seal leakage rate; Enthalpy of steam leakage from the first shaft seal, kJ / kg; Determine the extraction ratio from the heat balance equation of H2 : (4) (5) Hydrophobicity of H2 : (6) For the second shaft seal leakage rate; reheat steam coefficient : (7) 2.3, High-pressure heater No. 3 (H3): The average specific volume of the water supply is expressed in m³ / kg. The outlet pressure of the water pump; The inlet pressure of the water pump is in MPa; For the efficiency of the feedwater pump, the enthalpy rise of the feedwater pump is... kJ / kg: (8) Specific enthalpy of third-stage extraction steam, kJ / kg; The specific enthalpy at the outlet of the third deaerator, kJ / kg; Specific enthalpy at the outlet of the fourth heater, kJ / kg; Determine the extraction ratio from the heat balance equation of H3 : (9) (10) Hydrophobicity of H3 : (11) 2.4 Deaerator HD Steam for heating the deaerator; Steam for steam-driven feedwater pumps; fourth stage steam extraction : (12) Deaerator inlet water coefficient : (13) Because the inlet and outlet flow rates of the deaerator are different, Since the heater efficiency is an unknown, to avoid having two unknowns in the final heat balance equation, we can initially disregard it. Write the heat balance equation for the deaerator. ,Right now: (14) Among them, the enthalpy of water intake kJ / kg; (15) Specific enthalpy of the fourth-stage extraction steam, kJ / kg; deaerator heating steam. : (16) Deaerator outlet main condensate fraction : (17) HD air extraction share : (18) 2.5, No. 5 low-pressure heater (H5): Specific enthalpy of the fifth-stage extraction steam, kJ / kg; The specific enthalpy at the outlet of the sixth heater, kJ / kg; (19) Determining the extraction volume using the heat balance formula of H5 : (20) H5 water transfer coefficient : (twenty one) 2.6, No. 6 low-pressure heater (H6): Specific enthalpy of the sixth-stage extraction steam, kJ / kg; Specific enthalpy at the outlet of the fifth deaerator, kJ / kg; Specific enthalpy at the outlet of the sixth deaerator, kJ / kg; The specific enthalpy at the outlet of the seventh heater is given in kJ / kg; the extraction fraction is determined using the heat balance equation of H6. : (twenty two) (twenty three) H6 water transfer coefficient : (twenty four) 2.7, No. 7 low-pressure heater (H7): Specific enthalpy of the seventh-stage extraction steam, kJ / kg; Specific enthalpy at the outlet of the seventh deaerator, kJ / kg; The specific enthalpy at the outlet of the eighth heater, kJ / kg; calculate the extraction ratio using the heat balance method for H7. : (25) (26) H7 hydrophobicity : (27) 2.8 and 8 low-pressure heaters (H8): Specific enthalpy of the eighth stage extraction steam, kJ / kg; Second shaft seal leakage rate; Third shaft seal leakage rate; Enthalpy of steam leakage from the second shaft seal, kJ / kg; Third shaft seal leakage vapor specific enthalpy, kJ / kg; Condensed steam share; (28) (29) (30) H8's thermal balance method for determining the air extraction ratio : (31) Condensed steam share: (32) (33) 3. Steam volume Calculation verification and power verification (34) 3.1 Calculation , Specific enthalpy rise of reheat steam, kJ / kg; specific internal work of condensed steam. kJ / kg: (35) Let be the power generation capacity of the steam turbine, expressed in kW; Mechanical efficiency Generator efficiency; steam turbine steam consumption : (36) Insufficient work coefficient of first-stage steam extraction : (37) Insufficient work coefficient of the second stage extraction steam : (38) Insufficient work coefficient of third-stage steam extraction : (39) Fourth stage extraction power deficiency coefficient : (40) Fifth stage extraction power deficiency coefficient : (41) The coefficient of insufficient work done by the sixth stage extraction steam : (42) The coefficient of insufficient work done by the seventh stage extraction steam : (43) The coefficient of insufficient work done by the eighth stage extraction steam : (44) Insufficient work coefficient of steam extraction at the first shaft seal : (45) Insufficient work coefficient of second shaft seal extraction steam : (46) Insufficient work coefficient of third shaft seal extraction steam : (47) Insufficient extraction of steam power increases steam consumption coefficient : (48) Steam turbine new steam consumption : (49) 1kg of new car fuel is more powerful kJ / kg: (50) Power of steam turbine generator kW: (51) Calculation error: (52) 4. Calculation of thermal economic indicators The heat brought back by the feedwater; the specific heat consumption of 1 kg of fresh steam. kJ / kg: (53) Steam turbine absolute internal efficiency : (54) Absolute electrical efficiency of steam turbine generator set : (55) Steam turbine generator set heat rate kJ / (kW·h): (56) Steam turbine generator set steam consumption rate kg / (kW·h): (57) 5. Calculation of absolute values ​​of each soda / water flow rate The hydrophobic fraction coefficient before entering the mixing point; the total water fraction coefficient after mixing. : (58) Hydrophobic specific enthalpy, kJ / kg; total specific enthalpy of the mixed water flow kJ / kg: (59) (60) Calculation Example: This invention takes a 600MW thermal power unit as an example, and the specific parameters are shown in Table 1 below: Table 1 Overall Parameters of the Unit

[0027] Request the air extraction ratio :

[0028] Hydrophobicity of H1 :

[0029] Request the air extraction ratio :

[0030] Hydrophobicity of H2 :

[0031] Reheat steam coefficient :

[0032] Enthalpy rise of water pump kJ / kg:

[0033] Request the air extraction ratio :

[0034] Hydrophobicity of H3 :

[0035] Deaerator heating steam :

[0036] Deaerator outlet main condensate fraction :

[0037] HD air extraction share :

[0038] Request the air extraction ratio : Water transport coefficient at ℃H5 :

[0039] Request the air extraction ratio :

[0040] H6 water transfer coefficient : =

[0041] Request the air extraction ratio :

[0042] H7 hydrophobicity :

[0043] Request the air extraction ratio :

[0044] Condensed steam share:

[0045]

[0046] Condensation of internal energy kJ / kg:

[0047] Steam turbine steam consumption :

[0048] Insufficient work coefficient of first-stage steam extraction :

[0049] Insufficient work coefficient of the second stage extraction steam :

[0050] Insufficient work coefficient of third-stage steam extraction :

[0051] Fourth stage extraction power deficiency coefficient :

[0052] Fifth stage extraction power deficiency coefficient :

[0053] The coefficient of insufficient work done by the sixth stage extraction steam : =

[0054] The coefficient of insufficient work done by the seventh stage extraction steam :

[0055] The coefficient of insufficient work done by the eighth stage extraction steam :

[0056] Insufficient work coefficient of steam extraction at the first shaft seal :

[0057] Insufficient work coefficient of second shaft seal extraction steam :

[0058] Insufficient work coefficient of third shaft seal extraction steam :

[0059] Insufficient extraction of steam power increases steam consumption coefficient :

[0060] Steam turbine new steam consumption :

[0061] 1kg of new car fuel is more powerful kJ / kg:

[0062] Power of steam turbine generator MW:

[0063] Calculation error:

[0064] Specific heat consumption of 1kg of new car kJ / kg:

[0065] Steam turbine absolute internal efficiency :

[0066] Absolute electrical efficiency of steam turbine generator set :

[0067] Steam turbine generator set heat rate kJ / (kW·h):

[0068] Steam turbine generator set steam consumption rate kg / (kW·h):

[0069] Steam Turbine Regenerative System Calculation Table

[0070] .

[0071] Example 2 See Figure 2 The system for calculating the thermal economic indicators of steam turbine units includes: The parameter acquisition module is used to acquire the original operating thermodynamic parameters of the steam turbine unit, including the leakage steam ratio and specific enthalpy of each shaft seal; The heat balance equation establishment module is used to establish heat balance equations for each stage of the regenerating equipment based on the original operating thermodynamic parameters and in accordance with the steam-water flow of the regenerating system, taking into account the effects of equipment efficiency, shaft seal leakage, and the gradual gravity flow of condensate. The heat balance equation solving module is used to solve the heat balance equations at each level step by step to obtain the extraction steam share, condensate share and condensate share at each level. The new steam consumption calculation module is used to calculate the insufficient work coefficient of each stage of steam extraction and shaft seal leakage based on the extraction ratio of each stage and the original operating thermodynamic parameters, and to calculate the new steam consumption based on the insufficient work coefficient. The actual output power calculation module is used to calculate the actual output power of the computer group based on the new steam consumption, the extraction steam share of each stage, the condensate share, the condensate share, and the original operating thermodynamic parameters. The parameter closed-loop verification module is used to perform closed-loop verification between the actual output power and the measured power generation of the unit. When the error exceeds the preset range, the original operating thermodynamic parameters are corrected and the above steps are repeated until the error meets the requirements, and the verified calculation parameters are obtained. The index calculation module is used to calculate the thermal economy index of the computer group based on the verified calculation parameters.

[0072] Example 3 See Figure 3 An electronic device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements a method for calculating the thermal economic indicators of a steam turbine unit.

[0073] Example 4 A computer-readable storage medium storing a computer program, which, when executed by a processor, implements a method for calculating the thermal economic indicators of a steam turbine unit.

[0074] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, read-only optical discs, optical storage, etc.) containing computer-usable program code.

[0075] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0076] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0077] These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable apparatus for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for calculating the thermal economic indicators of a steam turbine unit, characterized in that, Includes the following steps: Obtain the original operating thermodynamic parameters of the steam turbine unit, including the leakage steam ratio and specific enthalpy of each shaft seal; Based on the original operating thermodynamic parameters, heat balance equations are established for each stage of the regenerating equipment according to the steam-water flow of the regenerating system, taking into account the effects of equipment efficiency, shaft seal leakage, and the gradual gravity flow of condensate. The heat balance equations for each stage are solved step by step to obtain the extraction steam share, condensate share and condensate steam share for each stage. Based on the extraction steam ratio of each stage and the original operating thermodynamic parameters, the insufficient work coefficient of extraction steam at each stage and shaft seal leakage is calculated, and the new steam consumption is calculated based on the insufficient work coefficient. Based on the new steam consumption, the extraction steam share at each stage, the condensate share, the condensate share, and the original operating thermodynamic parameters, the actual output power of the computer group; A closed-loop verification is performed on the actual output power and the measured power generation of the unit. If the error exceeds the preset range, the original operating thermodynamic parameters are corrected and the above steps are repeated until the error meets the requirements, and the verified calculation parameters are obtained. The computer group's thermal economy index is based on the verified calculation parameters.

2. The method for calculating the thermal economic index of a steam turbine unit according to claim 1, characterized in that, The regenerative equipment at each stage includes a high-pressure heater, a deaerator, and a low-pressure heater connected in sequence from high to low pressure.

3. The method for calculating the thermal economic index of a steam turbine unit according to claim 1, characterized in that, The order of solving the heat balance equations at each level is as follows: starting from the regenerating device with the highest pressure, the solution is sequentially applied along the steam-water flow path of the regenerating system to the regenerating device with the lowest pressure.

4. The method for calculating the thermal economic index of a steam turbine unit according to claim 3, characterized in that, The heat balance equation for each stage of regenerative equipment uses only the extraction steam ratio of that stage as the unknown quantity, while the condensate ratio of the previous stage's higher-pressure regenerative equipment is substituted into the heat balance equation of that stage as the known quantity.

5. The method for calculating the thermal economic index of a steam turbine unit according to claim 1, characterized in that, The calculation of the new fuel consumption based on the insufficient work coefficient is as follows: The steam consumption under condensing conditions is calculated based on the original operating thermodynamic parameters. The new steam consumption is then calculated by combining the insufficient work coefficient, the extraction steam share of each stage, and the leakage steam share of each shaft seal.

6. The method for calculating the thermal economic index of a steam turbine unit according to claim 1, characterized in that, The closed-loop verification is a comprehensive check of the thermal balance of the fully regenerative system. It corrects the original operating thermodynamic parameters by power comparison and iterative calculation.

7. The method for calculating the thermal economic index of a steam turbine unit according to claim 1, characterized in that, The thermal economic indicators include heat rate, steam rate, absolute internal efficiency, and absolute electrical efficiency.

8. A system for calculating the thermal economic performance of a steam turbine unit, characterized in that, include: The parameter acquisition module is used to acquire the original operating thermodynamic parameters of the steam turbine unit, including the leakage steam ratio and specific enthalpy of each shaft seal; The heat balance equation establishment module is used to establish heat balance equations for each stage of the regenerating equipment based on the original operating thermodynamic parameters and in accordance with the steam-water flow of the regenerating system, taking into account the effects of equipment efficiency, shaft seal leakage, and the gradual gravity flow of condensate. The heat balance equation solving module is used to solve the heat balance equations at each level step by step to obtain the extraction steam share, condensate share and condensate share at each level. The new steam consumption calculation module is used to calculate the insufficient work coefficient of each stage of steam extraction and shaft seal leakage based on the extraction ratio of each stage and the original operating thermodynamic parameters, and to calculate the new steam consumption based on the insufficient work coefficient. The actual output power calculation module is used to calculate the actual output power of the computer group based on the new steam consumption, the extraction steam share of each stage, the condensate share, the condensate share, and the original operating thermodynamic parameters. The parameter closed-loop verification module is used to perform closed-loop verification between the actual output power and the measured power generation of the unit. When the error exceeds the preset range, the original operating thermodynamic parameters are corrected and the above steps are repeated until the error meets the requirements, and the verified calculation parameters are obtained. The index calculation module is used to calculate the thermal economy index of the computer group based on the verified calculation parameters.

9. An electronic device, characterized in that, It includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method for calculating the thermal economic index of a steam turbine unit as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the method for calculating the thermal economic indicators of a steam turbine unit as described in any one of claims 1-7.

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