Method for determining thermal efficiency of thermodynamic cycle and computer storage medium
By establishing a standardized thermal efficiency calculation framework and determining thermodynamic properties, the problem of cumbersome, time-consuming, and error-prone calculations of thermal efficiency in existing technologies has been solved, enabling rapid and accurate acquisition of thermal efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-18
- Publication Date
- 2026-03-27
AI Technical Summary
Existing technologies for determining the thermal efficiency of thermodynamic cycles suffer from problems such as tedious and time-consuming calculations, inability to handle complex cycles and novel working fluids, and large errors under specific conditions.
By obtaining the configuration identifier and calculation parameters of the thermodynamic cycle, a standardized thermal efficiency calculation framework is established. The thermodynamic properties of the initial state point and the properties of subsequent state points are determined in sequence, and finally the energy data is obtained, enabling rapid and accurate thermal efficiency calculation.
It enables faster and more accurate acquisition of the thermal efficiency of thermodynamic cycles under different cycle configurations, operating conditions, and equipment conditions, avoiding the repetitive table lookup process of traditional methods and improving calculation efficiency and accuracy.
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Abstract
Description
TECHNICAL FIELD
[0001] Embodiments of the present application relate to the field of data processing methods, particularly suitable for specific functions, and particularly to a method for determining the thermal efficiency of a thermodynamic cycle and a computer storage medium. BACKGROUND
[0002] The statements herein are merely provided to give general background information on the present application, and do not necessarily constitute the prior art.
[0003] Determining the thermal efficiency of a thermodynamic cycle is the core of system design, optimization and performance analysis in the field of thermodynamic engineering, and the core is to obtain the accurate thermophysical properties of the working medium in the thermodynamic process, such as specific enthalpy, specific entropy, temperature, pressure and specific volume, etc.
[0004] Thermodynamic cycles mainly include Rankine cycle, Brayton cycle, regenerative cycle, reheating cycle, etc. Different cycle types have different characteristics, and when determining the thermal efficiency of a thermodynamic cycle, a technician needs to look up a table for calculation or use an empirical formula or a simplified model for estimation according to the type of the cycle, the working medium and the working condition. SUMMARY
[0005] In the following, a brief summary of the present application is given to provide a basic understanding of some aspects of the present application. It should be understood that this summary is not an exhaustive overview of the present application. It is not intended to identify key or important parts of the present application, nor is it intended to limit the scope of the present application. Its purpose is merely to give some concepts in a simplified form as a prelude to the more detailed description discussed later.
[0006] In a first aspect, embodiments of the present application provide a method for determining the thermal efficiency of a thermodynamic cycle, comprising the following steps: S10: obtaining an identifier of a configuration of the thermodynamic cycle and a calculation parameter; S20: determining a thermal efficiency calculation framework of the configuration of the thermodynamic cycle according to the identifier and the calculation parameter; S30: obtaining input working condition parameters and equipment performance parameters; S40: determining complete thermodynamic properties of initial state points in the configuration of the thermodynamic cycle according to the working condition parameters and the equipment performance parameters; S50: determining the thermodynamic properties of each state point subsequent to the initial state points in the configuration of the thermodynamic cycle according to the thermal efficiency calculation framework determined in the S20 step and the complete thermodynamic properties of the initial state points determined in the S40 step; S60: determining energy data of the equipment according to the thermodynamic properties of each state point determined in the S50 step and the performance parameters of the equipment; S70: determining the thermal efficiency of the thermodynamic cycle according to the energy data.
[0007] Embodiments of the present application determine the thermal efficiency of a thermodynamic cycle by standardizing the process of determining the thermal efficiency of the thermodynamic cycle, sequentially determining a thermal efficiency calculation framework of a cycle configuration and a working condition equipment performance parameter, obtaining complete thermodynamic properties of initial state points, determining thermodynamic properties of each subsequent state point, and finally obtaining energy data to determine the thermal efficiency of the thermodynamic cycle. Through the embodiments of the present application, the thermal efficiency of a thermodynamic cycle under different cycle configurations, working conditions and equipment conditions can be obtained more quickly and accurately using one method, and repeated table lookup using traditional methods is avoided.
[0008] In a second aspect, embodiments of the present application provide a method for determining the thermal efficiency of a thermodynamic cycle, comprising the following steps: S10: determining the type of the thermodynamic cycle; S20: determining the thermodynamic process contained in the thermodynamic cycle according to the type of the thermodynamic cycle; S30: determining the state parameter of each state point of the thermodynamic process according to the thermodynamic process; and S40: determining the thermal efficiency of the thermodynamic cycle according to the state parameter.
[0009] Embodiments of the present application determine the thermal efficiency of a thermodynamic cycle by sequentially determining the type of the thermodynamic cycle, the thermodynamic process and the state parameter of each state point. Through the embodiments of the present application, the thermal efficiency of a thermodynamic cycle can be obtained without repeated table lookup using traditional methods, and the accuracy and efficiency of obtaining the thermal efficiency of a thermodynamic cycle are improved.
[0010] In a third aspect, embodiments of the present application provide a computer storage medium, which stores a computer program. The computer program comprises program instructions, and when the program instructions are executed by a processor, the method provided in the first aspect of the embodiments of the present application is executed. BRIEF DESCRIPTION OF DRAWINGS
[0011] Other objects and advantages of the present application will become apparent and help to understand the present application from the following description of embodiments of the present application with reference to the accompanying drawings.
[0012] Figure 1 FIG. 1 is a flowchart of a method for determining the thermal efficiency of a thermodynamic cycle provided by embodiments of the present application.
[0013] Figure 2 FIG. 2 is a schematic diagram of a simple regenerative Brayton cycle in embodiments of the present application.
[0014] Figure 3 FIG. 3 is a temperature-entropy diagram (T-S diagram) of a simple regenerative Brayton cycle in embodiments of the present application.
[0015] It should be noted that the accompanying drawings are not necessarily drawn to scale, but are merely shown in a schematic manner so as not to affect the understanding of the reader.
[0016] LEGEND OF REFERENCE NUMBERS 1, compressor; 2. Recuperator; 21. Recuperator cold end; 22. Recuperator hot end; 3. Heat exchanger; 4. Turbine; 5. Cooler; 6. Generator; A. Compressor inlet; B. Compressor outlet; C. Recuperator cold end outlet; D. Turbine inlet; E. Turbine outlet; F. Recuperator hot end outlet. DETAILED DESCRIPTION
[0017] Exemplary embodiments of the present application will be described herein below with reference to the accompanying drawings. In the description, all features that are not described in detail of the actual embodiments have been omitted for the sake of clarity and conciseness. It should be appreciated, however, that numerous implementation-specific decisions must be made in order to develop literally any such actual implementation and also that these specific decisions will yield an implementation that is specifically tailored to the particular needs of a given implementation, such as conforming to the specific constraints of the system and business at hand, which will vary from one implementation to another. Moreover, it should be appreciated that, while the development effort might be complex and time consuming, it would be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure, to develop such an implementation in accordance with these teachings.
[0018] It is also noted herein that, although the present application has been described in reference to exemplary embodiments, various modifications can be made that do not depart from the spirit and scope of the application. Therefore, to the extent that such modifications do not depart from the spirit and scope of the application, they are intended to be included in the claims.
[0019] In the prior art, the thermal efficiency of a thermodynamic cycle is often determined using a conventional method, which requires the use of thermodynamic charts and property tables to find the corresponding thermodynamic parameters in the charts or tables according to known parameters, and to obtain the accurate values of non-tabular data through manual interpolation.
[0020] However, the process of determining the thermal efficiency of a thermodynamic cycle through table lookup and interpolation is tedious and time-consuming, and when faced with complex cycles or multiple-point calculations, a large amount of time is required. When the working medium or working condition changes, the previous calculation results cannot be used, and need to be recalculated. At the same time, charts and tables usually only cover a few commonly used working media, such as water, ammonia and a few refrigerants; they cannot cope with the analysis of new working media. In addition, when using empirical formulas or simplified models to estimate the properties, the error is large when deviating from ideal conditions such as high pressure, near-critical region and two-phase region, and the formulas are usually only effective for specific working media. Currently, there is still no method that can be used for the thermal efficiency of thermodynamic cycles of various cycle types and working conditions of working media.
[0021] An embodiment of the present application provides a method for determining the thermal efficiency of a thermodynamic cycle, as shown in Figure 1 Figure 1 is a flowchart of a method for determining thermal efficiency of a thermodynamic cycle provided by an embodiment of the present application, which comprises the following steps: S10: obtaining an identifier of a configuration of the thermodynamic cycle and a calculation parameter; S20: determining a thermal efficiency calculation framework of the configuration of the thermodynamic cycle according to the identifier and the calculation parameter; S30: obtaining input working condition parameters and equipment performance parameters; S40: determining complete thermodynamic properties of an initial state point of the configuration of the thermodynamic cycle according to the working condition parameters and the equipment performance parameters; S50: determining thermodynamic properties of each subsequent state point of the initial state point in the configuration of the thermodynamic cycle according to the thermal efficiency calculation framework determined in the S20 step and the complete thermodynamic properties of the initial state point determined in the S40 step; S60: determining energy data of the equipment according to the thermodynamic properties of each state point determined in the S50 step and the performance parameters of the equipment; and S70: determining the thermal efficiency of the thermodynamic cycle according to the energy data.
[0022] Embodiments of the present application standardize the process of determining the thermal efficiency of the thermodynamic cycle, and in turn determine the thermal efficiency calculation framework of the cycle configuration and the working condition equipment performance parameters, obtain the complete thermodynamic properties of the initial state point, determine the thermodynamic properties of each subsequent state point, and finally obtain the energy data to determine the thermal efficiency of the thermodynamic cycle. Through the embodiments of the present application, the thermal efficiency of the thermodynamic cycle of different cycle configurations, working conditions and equipment conditions can be obtained more quickly and accurately using one method, and repeated table lookup using traditional methods is avoided.
[0023] In some embodiments, in the S10 step, the identifier is used to uniquely determine the configuration of the thermodynamic cycle, and the cycle configuration is any one of the following cycles: Rankine cycle, regenerative cycle, reheat cycle, Brayton cycle or Stirling cycle.
[0024] Embodiments of the present application determine a unique cycle configuration through the identifier, so as to subsequently determine the thermal efficiency calculation framework of the configuration of the thermodynamic cycle.
[0025] In some embodiments, in the S10 step, the calculation parameter at least includes a working medium type identification or an initial state parameter.
[0026] Embodiments of the present application limit the working medium type or the initial state in the calculation process by obtaining the working medium type identification or the initial state parameter, so as to subsequently determine the complete thermodynamic properties of the initial state point of the configuration of the thermodynamic cycle.
[0027] In some embodiments, in the S20 step, the following steps are further included: S21: determining a standardized definition corresponding to the configuration of the thermodynamic cycle according to the identifier, and S22: determining the thermal efficiency calculation framework of the configuration of the thermodynamic cycle according to the standardized definition and the calculation parameter.
[0028] The embodiments of this application construct a calculation framework for the thermal efficiency of the corresponding thermodynamic cycle by determining the standardized definition corresponding to the cycle configuration, so that when using the method provided by the embodiments of this application to determine the thermal efficiency of the thermodynamic cycle, the thermal efficiency of the thermodynamic cycle of the same cycle type can be determined by a fixed standard and method.
[0029] In some embodiments, in step S21, the standardization definition includes the sequence number and physical meaning of all key state points contained in the configuration of the thermodynamic cycle, the sequence, type and order relationship of the standard thermodynamic processes connecting the state points, and the auxiliary calculation rules necessary to complete the thermal efficiency calculation.
[0030] The embodiments of this application define the specific content included in the standardized definition, so that the calculation framework for the thermal efficiency of the constructed thermodynamic cycle has complete data, processes and calculation rules required for calculation, so that when using the method provided by the embodiments of this application, the thermal efficiency of the thermodynamic cycle can be determined according to the process sequence and calculation rules in the standardized definition.
[0031] In some embodiments, in step S50, a convergence criterion is set, and the thermodynamic properties of each state point are determined based on the convergence criterion and auxiliary calculation rules.
[0032] The embodiments of this application establish convergence criteria so that processes that have mutual influences or require iterative calculations can determine the operation and termination of the calculation based on the convergence criteria, and obtain parameters that meet the conditions.
[0033] In some embodiments, in step S30, the operating parameters and equipment performance parameters include one or more of the following: compressor pressure ratio, turbine inlet temperature, turbine and compressor isentropic efficiency, regenerator minimum end difference, equipment pressure loss coefficient, or working fluid mass flow rate.
[0034] The embodiments of this application determine the above-mentioned operating condition parameters and equipment performance parameters in order to determine the thermodynamic properties of the initial point and each subsequent state point.
[0035] In some embodiments, the method for determining the thermal efficiency of a thermodynamic cycle includes the following steps: S10: determining the type of thermodynamic cycle; S20: determining the thermodynamic processes contained in the thermodynamic cycle according to the type of thermodynamic cycle; S30: determining the state parameters of each state point of the thermodynamic process according to the thermodynamic process; S40: determining the thermal efficiency of the thermodynamic cycle according to the state parameters.
[0036] The embodiments of this application determine the thermal efficiency of a thermal cycle by sequentially determining the type of the thermal cycle, the thermal process, and the state parameters at each state point. Through these embodiments, the thermal efficiency of the thermal cycle can be obtained by avoiding the repetitive lookup of tables using traditional methods, thus improving the accuracy and efficiency of obtaining the thermal efficiency of the thermal cycle.
[0037] In some embodiments, step S10 further includes the following steps: S11: obtaining an identifier for the configuration of the thermodynamic cycle, the identifier being used to uniquely determine the configuration of the thermodynamic cycle, the configuration of the thermodynamic cycle being any of the following cycles: Rankine cycle, regenerative cycle, reheat cycle, Brayton cycle, or Stirling cycle; S12: determining the configuration of the thermodynamic cycle based on the identifier.
[0038] The embodiments of this application identify a unique cycle configuration through an identifier so that the thermal efficiency of the thermodynamic cycle can be determined subsequently based on the configuration of the thermodynamic cycle.
[0039] A computer storage medium storing a computer program, the computer program including program instructions, which, when executed by a processor, perform the method in any of the foregoing embodiments.
[0040] To facilitate understanding, the method for determining the thermal efficiency of a thermodynamic cycle provided in this application will be further illustrated below using a simple regenerative Brayton cycle as an example.
[0041] See Figure 2 and Figure 3 , Figure 2 This is a schematic diagram of a simple regenerative Brayton cycle in an embodiment of this application. Figure 3 This is a temperature-entropy diagram (TS diagram) of a simple regenerative Brayton cycle in an embodiment of this application, where T on the vertical axis represents temperature and S on the horizontal axis represents entropy.
[0042] like Figure 2 As shown, the device utilizing a simple regenerative Brayton cycle includes a compressor 1, a regenerator 2, a heat exchanger 3, a steam turbine 4, a cooler 5, and a generator 6. The regenerator 2 includes a cold end 21 and a hot end 22. Based on the identifier "simple regenerative Brayton cycle," the cycle contains six key state points A to F: point A is the compressor inlet, point B is the compressor outlet, point C is the cold end outlet of the regenerator, point D is the steam turbine inlet, point E is the steam turbine outlet, and point F is the hot end outlet of the regenerator.
[0043] like Figure 3 As shown, the standard thermodynamic process sequence connecting these state points is as follows: A to B is an isentropic compression process, B to C is an isobaric regeneration process, C to D is an isobaric heating process, D to E is an isentropic expansion process, E to F is an isobaric regeneration process, and F to A is an isobaric cooling process.
[0044] Given a simple regenerative Brayton cycle configuration, input the basic calculation parameters, identifying the working fluid as air or other gaseous working fluid; the initial state parameters are the compressor inlet pressure and temperature.
[0045] A standardized definition corresponding to a simple regenerative Brayton cycle is established, which includes a digital calculation framework for six state point variables and their connections, and pre-defined interfaces for auxiliary calculation rules such as isentropic efficiency and regenerator performance.
[0046] Obtain detailed operating parameters and equipment performance parameters, including at least: compressor pressure ratio, turbine inlet temperature, turbine and compressor isentropic efficiency, minimum end difference of regenerator, equipment pressure loss coefficient, and working fluid mass flow rate.
[0047] Based on the type of working fluid and the inlet pressure and temperature of the compressor, the system automatically calls the standard working fluid thermophysical property database to obtain the complete thermodynamic properties of state point A, including specific enthalpy, specific entropy, etc.
[0048] According to the standardized definition, the program automatically calculates and solves for the thermodynamic property parameters from state points B to F in a set order.
[0049] Solving for state point B: According to the isentropic compression process, the ideal specific entropy at point B is the same as that at point A. The pressure at point B is obtained from the compressor pressure ratio. The ideal specific enthalpy is obtained by calling the working fluid thermophysical property database, inputting the working fluid name, known specific entropy, and pressure. Then, the actual specific enthalpy is calculated based on the isentropic compression efficiency. Finally, the actual temperature and specific entropy at point B are obtained again by calling the working fluid thermophysical property database using the pressure and actual specific enthalpy conditions.
[0050] Solving for state point D: Based on the known pressure and the input temperature at point D, call the working fluid thermophysical property database, input the working fluid name, pressure, and temperature, and obtain the specific enthalpy and specific entropy at point D.
[0051] Solving for state point E: According to the isentropic expansion process, the ideal specific entropy at point E is the same as that at point D. The pressure is obtained from the pressure at point A and the compressibility coefficients of each device. The ideal specific enthalpy at point E is obtained by calling the working fluid thermophysical property database and inputting the working fluid name, ideal specific entropy, and pressure. The actual specific enthalpy at point E is obtained based on the isentropic efficiency of the steam turbine. Then, using the pressure and actual specific enthalpy at point E as conditions, the working fluid thermophysical property database is called again to obtain the temperature and actual specific entropy at point E.
[0052] Solving for state point F: According to the definition of regenerator efficiency, an initial value is assumed for efficiency, and subsequent iterations will be performed. Given the regenerator efficiency and the temperatures at points E and B, the temperature at point F can be obtained. The specific entropy and specific enthalpy at point F are obtained by calling the working fluid thermophysical property database.
[0053] Solving for state point C: Based on the law of conservation of energy, the actual specific enthalpy of point C is obtained from the actual specific enthalpy of points B, E, and F. Using the specific enthalpy and pressure at point C as conditions, the working fluid thermophysical property database is called to obtain the temperature and specific entropy at point C.
[0054] The parameters to be iteratively calculated are obtained based on the convergence criterion. Given the minimum end difference of the regenerator, by changing the small increment of the regenerator efficiency, the minimum end difference of the regenerator, i.e., the temperature difference between points F and B, is obtained in each iteration. The iteration is completed when the difference meets the specified minimum end difference of the regenerator.
[0055] After obtaining all thermodynamic property parameters at the six state points, the power consumption of the compressor, the power done by the turbine, the heat absorption of the heat exchanger, and the net output power of the cycle can be determined based on the specific enthalpy and mass flow rate at all state points.
[0056] The above calculations are performed using the obtained net output power of the cycle and the heat absorbed by the heat exchanger to obtain the thermal efficiency of this cycle.
[0057] When analyzing the impact of different input parameters on thermal efficiency, if a single input parameter is modified in the input interface while other parameters remain unchanged, the change in input parameter is automatically detected, and the calculation process is automatically retried. Within a short time, all recalculations are completed, and a new list of all state point parameters, energy data of each device, and system performance indicators, including the cycle thermal efficiency value, are output.
[0058] In addition, it can generate and output all thermodynamic parameters for each defined state point, making it convenient to verify intermediate results.
[0059] Regarding the embodiments of this application, it should also be noted that, without conflict, the embodiments of this application and the features in the embodiments can be combined with each other to obtain new embodiments.
[0060] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. The scope of protection of this application shall be determined by the scope of the claims.
Claims
1. A method for determining the thermal efficiency of a thermodynamic cycle, characterized in that, It includes the following steps: S10: Obtain the identifier of the configuration of the thermodynamic cycle and the calculation parameters; S20: Determine the thermal efficiency calculation framework for the configuration of the thermodynamic cycle based on the identifier and calculation parameters; S30: Obtain the input operating condition parameters and equipment performance parameters; S40: Based on the operating parameters and equipment performance parameters, determine the complete thermodynamic properties of the initial state point of the configuration of the thermodynamic cycle; S50: Based on the thermal efficiency calculation framework determined in step S20 and the complete thermodynamic properties of the initial state point determined in step S40, determine the thermodynamic properties of each subsequent state point in the configuration of the thermodynamic cycle. S60: Determine the energy data of the device based on the thermodynamic properties of each state point determined in step S50 and the performance parameters of the device; S70: Determine the thermal efficiency of the thermodynamic cycle based on the energy data.
2. The method according to claim 1, characterized in that, In step S10, The identifier is used to uniquely identify the configuration of the thermodynamic cycle, which is any of the following cycles: Rankine cycle, regenerative cycle, reheat cycle, Brayton cycle, or Stirling cycle.
3. The method according to claim 1, characterized in that, In step S10, The calculation parameters include at least: working medium type identifier or initial state parameters.
4. The method according to claim 1, characterized in that, Step S20 also includes the following steps: S21: Based on the identifier, determine the standardized definition corresponding to the configuration of the thermodynamic cycle. S22: Determine the thermal efficiency calculation framework for the configuration of the thermodynamic cycle based on the standardized definition and the calculation parameters.
5. The method according to claim 4, characterized in that, In step S21, The standardized definition includes the sequence number and physical meaning of all key state points contained in the configuration of the thermodynamic cycle, the sequence, type and order of the standard thermodynamic processes connecting each state point, and the auxiliary calculation rules necessary to complete the thermal efficiency calculation.
6. The method according to claim 1, characterized in that, In step S50, a convergence criterion is set, and the thermodynamic properties of each state point are determined based on the convergence criterion and auxiliary calculation rules.
7. The method according to claim 1, characterized in that, In step S30, the operating parameters and equipment performance parameters include one or more of the following: compressor pressure ratio, turbine inlet temperature, turbine and compressor isentropic efficiency, regenerator minimum end difference, equipment pressure loss coefficient, or working fluid mass flow rate.
8. A method for determining the thermal efficiency of a thermodynamic cycle, characterized in that, S10: Determine the type of the thermodynamic cycle; S20: Determine the thermodynamic processes included in the thermodynamic cycle according to the type of the thermodynamic cycle; S30: Determine the state parameters of each state point of the thermodynamic process based on the thermodynamic process; S40: Determine the thermal efficiency of the thermodynamic cycle based on the state parameters.
9. The method according to claim 8, characterized in that, Step S10 also includes the following steps: S11: Obtain an identifier for the configuration of the thermodynamic cycle, the identifier being used to uniquely determine the configuration of the thermodynamic cycle, the configuration of the thermodynamic cycle being any of the following cycles: Rankine cycle, regenerative cycle, reheat cycle, Brayton cycle, or Stirling cycle. S12: Determine the configuration of the thermodynamic cycle based on the identifier.
10. A computer storage medium, characterized in that, The computer storage medium stores a computer program, which includes program instructions that, when executed by a processor, perform the method as described in any one of claims 1-9.