Geothermal organic Rankine cycle unit design system and method

Abstract

The invention relates to a geothermal organic Rankine cycle unit design system and method, and the system comprises a thermodynamic parameter design system which is used for calculating circulating thermodynamic parameters; the loop parameter iteration system is used for determining the optimal loop parameter of the unit and evaluating the feasibility of the design scheme; the economic benefit evaluation system is used for evaluating economic indexes of the design scheme; the data processing system is used for summarizing design parameters, comparing the design parameters with a reference scheme and optimizing the design scheme; the design scheme display system is used for generating and displaying detailed comparison between the optimal design scheme and the suboptimal design scheme; the method comprises the following steps: designing geothermal organic Rankine cycle parameters; carrying out geothermal organic Rankine cycle feasibility analysis; iteratively solving the optimal heat exchanger area; evaluating the economic benefit of the geothermal organic Rankine cycle; and constructing a design database of the geothermal organic Rankine cycle unit. The system and the method can solve the problems that the geothermal organic Rankine cycle unit is complex in design, high in design cost and difficult in design scheme evaluation.

Description

Technical Field

[0001] The present invention relates to the technical field of geothermal power generation, and in particular to a geothermal organic Rankine cycle unit design system and method. Background Art

[0002] Geothermal Organic Rankine Cycle (ORC) is a technology that uses low-grade heat sources (such as geothermal hot water) to generate electricity. In a geothermal organic Rankine cycle power generation system, unit design and its economic benefit analysis are the key to ensuring efficient operation of the system. However, traditional design methods usually rely on experience and complicated calculations, making it difficult to efficiently optimize the balance between thermodynamic performance and economic benefits, and the design process is complex and time-consuming; in addition, it is difficult to uniformly compare different indicator dimensions between different schemes, and it is difficult to quantify the advantages and disadvantages of the schemes. Summary of the invention

[0003] The object of the present invention is to provide a geothermal organic Rankine cycle unit design system and method to solve the problems of complex design, high design cost and difficult design scheme evaluation of geothermal organic Rankine cycle units.

[0004] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a geothermal organic Rankine cycle unit design system, comprising:

[0005] Thermodynamic parameter design system, used to calculate the thermodynamic parameters of geothermal organic Rankine cycle;

[0006] Cycle parameter iteration system, used to determine the optimal cycle parameters of the unit through iterative calculation and evaluate the feasibility of the design scheme;

[0007] Economic benefit evaluation system, used to evaluate the economic indicators of design solutions;

[0008] Data processing system, used to summarize various design parameters and compare them with the benchmark solutions in the database to optimize the design solution;

[0009] Design alternatives display system, used to generate and display detailed comparison of optimal and suboptimal design alternatives.

[0010] The present invention also provides a method for designing a geothermal organic Rankine cycle unit based on the above system, comprising the following steps:

[0011] S1. Parameter design of geothermal organic Rankine cycle;

[0012] S2. Feasibility analysis of geothermal organic Rankine cycle;

[0013] S3, iterative solution of the optimal heat exchanger area;

[0014] S4. Economic benefit evaluation of geothermal organic Rankine cycle;

[0015] S5. Construction of geothermal organic Rankine cycle unit design database.

[0016] Furthermore, the geothermal organic Rankine cycle parameter design in step S1 includes the following steps:

[0017] S101) Input parameters: refrigerant type, ambient temperature and pressure, geothermal resource temperature and state, initial heat exchanger pinch point temperature difference, evaporation temperature, condensation temperature, superheat, subcooling and efficiency of each mechanical component; refrigerant state at two phase transition points inside the evaporator and two phase transition points inside the condenser, and further calculate the refrigerant state at the evaporator outlet and the condenser outlet;

[0018] S102) calculating, by thermodynamic state function: the refrigerant state under isentropic conditions at the turbine expander outlet and the working fluid pump outlet, and further calculating the refrigerant state at the turbine expander outlet and the working fluid pump outlet;

[0019] S103) calculating the geothermal resource temperature and the cooling medium temperature at the evaporator and condenser pinch points determined by the initial heat exchanger pinch point temperature difference, the geothermal resource temperature, and the ambient temperature;

[0020] S104) calculating the evaporator heat load by using the geothermal resource flow, the geothermal resource temperature at the evaporator narrow point, and the geothermal resource temperature;

[0021] S105) Calculate the refrigerant flow rate in the cycle based on the evaporator heat load and the thermodynamic state of the refrigerant at the inlet and outlet of the evaporator.

[0022] Furthermore, the feasibility analysis of the geothermal organic Rankine cycle in step S2 includes the following steps:

[0023] S201) Inputting the flow channel depth, flow channel gap, and flow channel pitch of the heat exchanger, preliminarily determining the number of heat exchanger plates and the heat exchanger width, and calculating the geometric parameters of the heat exchanger;

[0024] S202) calculating the refrigerant density, flow rate and refrigerant side pressure drop of the evaporator inlet through the thermodynamic state function;

[0025] S203) calculating the refrigerant density, flow rate and refrigerant side pressure drop at the condenser inlet through a thermodynamic state function;

[0026] S204) calculating the actual thermodynamic state of the refrigerant at the outlet of the evaporator and the condenser through the thermodynamic state function;

[0027] S205) determining whether there is a possibility of liquid hammer in the working fluid pump, if yes, the feasibility condition is not met, recording that the pressure drop is too large and reporting an error, otherwise proceed to the next step;

[0028] S206) Iteratively updating the refrigerant flow rate in the cycle;

[0029] S207) Calculate the enthalpy value error of the evaporator outlet, the refrigerant flow error in the cycle, and the enthalpy value error of the condenser outlet, and determine whether any of the errors is greater than a set threshold. If so, record that the pressure drop is too large and report an error, otherwise go to the next step;

[0030] S208) Iteratively calculate turbine output power, working fluid pump power consumption, cooling pump power consumption, cycle net output power, geothermal resource return water temperature, cooling water flow and return water temperature, evaporator heat load and condenser heat load, and cycle thermal efficiency.

[0031] Furthermore, the iterative solution of the optimal heat exchanger area in step S3 includes the following steps:

[0032] S301) calculating the initial heat exchanger area according to the initial heat exchanger heat transfer load and the assumed heat flux;

[0033] S302) calculating the Nusselt number and heat transfer coefficient on the refrigerant side;

[0034] S303) calculating the water side Reynolds number and Prandtl number, and obtaining the water side heat transfer coefficient;

[0035] S304) calculating the equivalent heat transfer coefficient in combination with the plate wall thickness, material and heat transfer coefficient;

[0036] S305) calculating the optimized heat exchanger area according to the heat load and the equivalent heat transfer coefficient;

[0037] S306) Calculate the relative error between the optimized heat exchanger area and the initial heat exchanger area, and determine whether the relative error is greater than the error setting threshold. If so, proceed to the next step. Otherwise, it is considered to be converged, and the obtained optimized heat exchanger area is the optimal area.

[0038] S307) Determine whether the heat flux is greater than the heat flux setting threshold. If so, it is considered converged and the optimized heat exchanger area is the optimal area. Otherwise, increase the assumed heat flux and return to step S301 to continue iterative calculation.

[0039] Furthermore, the geothermal organic Rankine cycle economic benefit evaluation in step S4 includes the following steps:

[0040] S401) Calculate geothermal resources, cooling water thermodynamic state, and refrigerant benchmark Status, import and export of each component in geothermal organic Rankine cycle state;

[0041] S402) Calculating the equipment purchase cost of the turbo expander, working fluid pump, geothermal heat pump, cooling water pump, evaporator and condenser;

[0042] S403) determining the initial equipment investment of the geothermal organic Rankine cycle unit and the geothermal well drilling cost;

[0043] S404) Preliminarily determine the annual operation time, expected life, and annual interest rate of the geothermal organic Rankine cycle unit, calculate the capital recovery rate, and calculate the initial investment and operation and maintenance costs during the expected life;

[0044] S405) Calculate the equivalent operating cost of the computer group, construct a linear algebraic equation group, and calculate the components of the geothermal organic Rankine cycle unit Flow costs;

[0045] S406) Calculate the net output of geothermal organic Rankine cycle and geothermal resources State-determined loop efficiency;

[0046] S407) calculating economic indicators including total unit investment, capital payback period and levelized cost of electricity (LCOE);

[0047] S408) Determine whether the economic indicators meet expectations, if yes, then end, otherwise determine whether the operating conditions can be changed, if yes, return to step S404) to re-determine the relevant operating conditions, if no, report to the data processing system and record in the design database.

[0048] Furthermore, the construction of the geothermal organic Rankine cycle unit design database in step S5 includes the following steps:

[0049] S501) Divide the geothermal resource intervals, use thermodynamic parameter design, cycle parameter iteration, economic benefit evaluation, data processing system calculation design plan, and store it in a relational database and a NoSQL database;

[0050] S502) Collecting unit operation data through the Internet of Things and SCADA system and storing it in a NoSQL database;

[0051] S503) Calculate the statistical indicators of the collected data and the design solution data, and optimize the query efficiency through the K-means clustering algorithm;

[0052] S504) using a deep neural network to perform parameter fitting and optimization, updating the model monthly, and outputting predicted indicators such as thermal efficiency, power generation, and economic payback period;

[0053] S505) Building an intelligent optimization system based on cloud computing, automatically matching the optimal design solution after the user inputs parameters and calculating the optimization score of the recommended solution;

[0054] S506) Establish an open database and collaborative optimization platform to support data uploading and solution optimization, and combine blockchain and digital twin technology to achieve data verification and remote monitoring;

[0055] S507) Update the database regularly. If the deviation between new data and historical data exceeds a threshold, model retraining is triggered, and reinforcement learning and genetic algorithms are used for iterative optimization.

[0056] Compared with the prior art, the present invention has the following beneficial effects:

[0057] 1) The present invention integrates multiple systems (thermodynamic parameter design system, cycle parameter design system, pressure drop calculation system, economic benefit evaluation system, etc.) to comprehensively design and optimize the geothermal organic Rankine cycle unit. This systematic design method ensures the coordination and integration of various links, effectively improves the design efficiency and accuracy, and avoids the shortcomings caused by single parameter optimization in traditional design.

[0058] 2) Traditional design methods often separate pressure drop calculation from economic benefit evaluation, but the present invention combines the two to ensure that while optimizing thermodynamic performance, the actual operating cost of the system is also taken into account. This integrated design greatly improves the overall efficiency of the system and avoids the risk of energy loss and excessive operating costs caused by ignoring the pressure drop problem.

[0059] 3) The heat exchanger area optimization in the invention reduces the heat exchanger design area and improves the heat exchange efficiency by calculating the Nusselt number and heat transfer coefficient. This not only improves the overall thermal efficiency of the system, but also effectively reduces the material cost of the heat exchanger, further improving the economy of the system.

[0060] 4) The present invention utilizes the design database and cloud computing platform to achieve continuous optimization of system design solutions. The database not only stores historical design solutions, but also supports continuous iterative optimization of design solutions through comparative analysis and integration with real-time data. In this way, not only the accuracy of the design is improved, but also the design can be quickly adjusted and optimized according to different usage scenarios, with high market adaptability.

[0061] 5) By integrating various optimization calculations and automated iteration processes, the person in charge of the geothermal plant does not need to deeply understand the complex mechanism of the organic Rankine cycle, nor does he need to rely on manual analysis by experts and scholars. This simplified design process significantly reduces the design difficulty, saves a lot of design manpower and material resources, and reduces the design and implementation costs of the overall project. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 is a flow chart for implementing a method for designing a geothermal organic Rankine cycle unit provided in an embodiment of the present invention;

[0063] Figure 2 is a flow chart for implementing the geothermal organic Rankine cycle parameter design in an embodiment of the present invention;

[0064] Figure 3is a flowchart for implementing the feasibility analysis of the geothermal organic Rankine cycle in an embodiment of the present invention;

[0065] Figure 4 is a flowchart for implementing iterative solution of the optimal heat exchanger area in an embodiment of the present invention;

[0066] Figure 5 is a flow chart for realizing the economic benefit evaluation of geothermal organic Rankine cycle in an embodiment of the present invention;

[0067] Figure 6 is a flowchart for implementing the construction of a design database for a geothermal organic Rankine cycle unit in an embodiment of the present invention;

[0068] Figure 7 This is the first page of the design solution table of the geothermal organic Rankine cycle unit designed in the embodiment of the present invention;

[0069] Figure 8 This is the second page of the design solution table of the geothermal organic Rankine cycle unit designed in the embodiment of the present invention;

[0070] Fig. 9 This is the third page of the design table of the geothermal organic Rankine cycle unit designed according to the embodiment of the present invention. DETAILED DESCRIPTION

[0071] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0072] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0073] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0074] This embodiment provides a geothermal organic Rankine cycle unit design system, including: a thermodynamic parameter design system, a cycle parameter iteration system, an economic benefit evaluation system, a data processing system and a design scheme display system.

[0075] The thermodynamic parameter design system is used to calculate the thermodynamic parameters of the geothermal organic Rankine cycle, such as temperature, pressure, etc.

[0076] The cycle parameter iteration system is used to determine the optimal cycle parameters of the unit, such as flow rate, expected life, etc., through iterative calculation, and evaluate the feasibility of the design solution.

[0077] The economic benefit evaluation system is used to evaluate the economic indicators of the design solution, such as capital investment, payback period, etc.

[0078] The data processing system is used to summarize various design parameters and compare them with the benchmark solutions in the database to optimize the design solution.

[0079] The design solution display system is used to generate and display a detailed comparison between the optimal and suboptimal design solutions.

[0080] This embodiment also provides a design method for a geothermal organic Rankine cycle unit based on the above system, such as Figure 1 As shown, the method comprises the following steps:

[0081] S1. Parameter design of geothermal organic Rankine cycle;

[0082] S2. Feasibility analysis of geothermal organic Rankine cycle;

[0083] S3, iterative solution of the optimal heat exchanger area;

[0084] S4. Economic benefit evaluation of geothermal organic Rankine cycle;

[0085] S5. Construction of geothermal organic Rankine cycle unit design database.

[0086] like Figure 2 As shown, the geothermal organic Rankine cycle parameter design in step S1 includes the following steps:

[0087] S101) Input parameters: refrigerant type, ambient temperature and pressure, geothermal resource temperature and state, initial heat exchanger pinch point temperature difference, evaporation temperature, condensation temperature, superheat, subcooling and efficiency of each mechanical component.

[0088] S102) Calculate by thermodynamic state function:

[0089] The thermodynamic state of the refrigerant at two phase transition points inside the evaporator determined by the evaporation temperature and dryness;

[0090] The thermodynamic state of the refrigerant at the evaporator outlet determined by the superheat and evaporation temperature;

[0091] The thermodynamic state of the refrigerant at two phase transition points inside the condenser determined by the condensation temperature and dryness;

[0092] The thermodynamic state of the refrigerant at the condenser outlet determined by the subcooling and condensing temperature;

[0093] The thermodynamic state of the refrigerant at the outlet of the turboexpander under isentropic conditions determined by the condensing pressure and the thermodynamic state of the refrigerant at the inlet of the evaporator;

[0094] The thermodynamic state of the refrigerant at the outlet of the turboexpander determined by the condensing pressure, the isentropic efficiency of the turboexpander and the thermodynamic state of the refrigerant under isentropic conditions at the outlet of the turboexpander;

[0095] The thermodynamic state of the refrigerant at the outlet of the working fluid pump under isentropic conditions determined by the evaporation pressure and the thermodynamic state of the refrigerant at the outlet of the condenser;

[0096] The thermodynamic state of the refrigerant at the outlet of the working fluid pump is determined by the evaporation pressure, the isentropic efficiency of the working fluid pump and the thermodynamic state of the refrigerant under isentropic conditions at the outlet of the working fluid pump.

[0097] S103) Calculating the geothermal resource temperature and the cooling medium temperature at the evaporator and condenser pinch points determined by the initial heat exchanger pinch point temperature difference, the geothermal resource temperature, and the ambient temperature.

[0098] S104) Calculating the evaporator heat load based on the geothermal resource flow, the geothermal resource temperature at the evaporator narrow point, and the geothermal resource temperature.

[0099] S105) Calculate the refrigerant flow rate in the cycle based on the evaporator heat load and the thermodynamic state of the refrigerant at the inlet and outlet of the evaporator.

[0100] like Figure 3 As shown, the feasibility analysis of the geothermal organic Rankine cycle in step S2 includes the following steps:

[0101] S201) Input the heat exchanger flow channel depth, flow channel gap, and flow channel pitch, preliminarily determine the number of heat exchanger plates and heat exchanger width, and calculate the heat exchanger geometric parameters.

[0102] S202) Calculate the refrigerant density, flow rate and refrigerant side pressure drop of the evaporator inlet through the thermodynamic state function.

[0103] S203) Calculate the refrigerant density, flow rate and refrigerant side pressure drop at the condenser inlet through the thermodynamic state function.

[0104] S204) Calculate the actual thermodynamic state of the refrigerant at the outlet of the evaporator and the condenser through the thermodynamic state function.

[0105] S205) Determine whether there is a possibility of liquid hammer in the working fluid pump. If yes, the feasibility condition is not met, record that the pressure drop is too large and report an error, otherwise go to the next step.

[0106] S206) Iteratively update the refrigerant flow in the cycle.

[0107] S207) Calculate the evaporator outlet enthalpy error, the refrigerant flow error in the cycle, and the condenser outlet enthalpy error, and determine whether any of the errors is greater than a set threshold. If so, record that the pressure drop is too large and report an error, otherwise go to the next step.

[0108] S208) Calculate the turbine output work, working fluid pump consumption work, cooling pump consumption work and cycle net output work in the cycle through the refrigerant flow rate in the cycle and the thermodynamic state of the refrigerant at the inlet and outlet of each component in the cycle.

[0109] S209) The geothermal resource return water temperature is determined by calculating the geothermal resource temperature, flow rate and specific heat capacity, the refrigerant flow rate in the cycle, and the refrigerant enthalpy value at the inlet and outlet of the evaporator.

[0110] S210) Calculate the cooling water flow rate and return water temperature by using the ambient temperature in the cycle, the condensing temperature, the narrow point temperature of the heat exchanger, the specific heat capacity of the cooling water, the refrigerant enthalpy value at the condenser outlet, and the refrigerant enthalpy value at the phase change point where the dryness of the refrigerant on the condenser side is 1.

[0111] S211) Iterate and update the evaporator heat load and the condenser heat load.

[0112] S212) Calculate the cycle thermal efficiency based on the evaporator heat load and the cycle net output work.

[0113] like Figure 4 As shown, the iterative solution of the optimal heat exchanger area in step S3 includes the following steps:

[0114] S301) Calculating the initial heat exchanger area according to the initial heat exchanger heat transfer load and the assumed heat flux.

[0115] S302) Calculate the Nusselt number and heat transfer coefficient on the refrigerant side.

[0116] S303) Calculate the water side Reynolds number and Prandtl number, and obtain the water side heat transfer coefficient.

[0117] S304) Calculate the equivalent heat transfer coefficient by combining the plate wall thickness, material and heat transfer coefficient.

[0118] S305) Calculate the optimized heat exchanger area according to the heat load and the equivalent heat transfer coefficient.

[0119] S306) Calculate the relative error between the optimized heat exchanger area and the initial heat exchanger area, and determine whether the relative error is greater than the error setting threshold. If so, proceed to the next step. Otherwise, it is considered to be converged, and the obtained optimized heat exchanger area is the optimal area.

[0120] S307) judging whether the heat flux is greater than the heat flux setting threshold according to the following formula, if so, it is considered converged, and the obtained optimized heat exchanger area is the optimal area, otherwise, the assumed heat flux is increased, and returning to step S301 to continue iterative calculation;

[0121]

[0122] S306) Calculate the relative error between the optimized heat exchanger area and the initial heat exchanger area, and determine whether the relative error is greater than the error setting threshold. If so, proceed to the next step. Otherwise, it is considered to be converged, and the obtained optimized heat exchanger area is the optimal area.

[0123] S307) Determine whether the heat flux is greater than the heat flux setting threshold. If so, it is considered converged and the optimized heat exchanger area is the optimal area. Otherwise, increase the assumed heat flux and return to step S301 to continue iterative calculation.

[0124] like Figure 5 As shown, the geothermal organic Rankine cycle economic benefit evaluation in step S4 includes the following steps:

[0125] S401) Calculate the geothermal resources, cooling water and the import and export of each component in the geothermal organic Rankine cycle by formula (1). state, where the turbine output power and the working fluid pump power consumption A state is defined as itself.

[0126] E i =m i ·[(h i -h 0 )-T 0 ·(s i -s 0 )] (1)

[0127] S402) Calculate the equipment purchase cost of the turbine expander, working fluid pump, geothermal pump, cooling water pump, evaporator and condenser using formulas (2) to (7).

[0128] log 10 (PEC turbine ) (2)

[0129] log 10 (PEC orcp )=a+b·log 10 (W orcp )+c·(log 10 (W orcp )) 2 (3)

[0130] log 10 (PEC hp )=a+b·og 10 (W hp )+c·(log 10 (W hp ))2 (4)

[0131] log 10 (PEC cp )=a+b·log 10 (W cp )+c·(log 10 (W cp )) 2 (5)

[0132] log 10 (PEC ev )=a+b·log 10 (A ev )+c·(log 10 (A ev )) 2 (6)

[0133] log 10 (PEC cn )=a+b·log 10 (A cn )+c·(log 10 (A cn )) 2 (7)

[0134] S403) Determine the initial equipment investment of the geothermal organic Rankine cycle unit and the geothermal well drilling cost by summing up the equipment purchase cost of the turbine expander, working fluid pump, geothermal heat pump, cooling water pump, evaporator and condenser and the magnification factor.

[0135] S404) Preliminarily determine the annual operating time, expected life span, and annual interest rate of the geothermal organic Rankine cycle unit, calculate the capital recovery rate, and calculate the initial investment and the operating and maintenance costs during the expected life span according to formula (8) and formula (9).

[0136]

[0137] S405) Calculate the equivalent operating cost of the computer group, construct a linear algebraic equation group, and calculate the components of the geothermal organic Rankine cycle unit Flow cost.

[0138] S406) Calculate the net output of geothermal organic Rankine cycle and geothermal resources State-determined loop efficiency.

[0139] S407) Calculate economic indicators including total unit investment, capital payback period and levelized cost of electricity (LCOE).

[0140] S408) Determine whether the economic indicators meet expectations, if yes, then end, otherwise determine whether the operating conditions can be changed, if yes, return to step S404) to re-determine the relevant operating conditions, if no, report to the data processing system and record in the design database.

[0141] like Figure 6 As shown, the construction of the geothermal organic Rankine cycle unit design database in step S5 includes the following steps:

[0142] S501) The geothermal resources working in the low temperature, medium temperature and high temperature ranges are divided into design ranges, and the unit design schemes under the waste heat recovery mode and the geothermal power generation mode are calculated through the thermodynamic parameter design system (1), the unit cycle parameter iteration system (2) and the unit economic benefit evaluation system (3), covering the cycle parameters and economic indicators of different heat source conditions, cooling conditions, unit configurations, working fluids and operation modes, and stored in the database. The database uses a relational database to store structured data, and combines a NoSQL database to store the unit operation data collected at a high frequency.

[0143] S502) Collect actual operation data, including geothermal resource temperature, flow rate, pressure; refrigerant evaporation temperature, condensation temperature, mass flow rate, circulation Efficiency, system power generation, cycle thermal efficiency and current electricity price. Data is collected in real time through IoT sensors and SCADA monitoring systems. The data format uses JSON structure, and is collected once at set sampling times and stored in a NoSQL database.

[0144] S503) Calculate the statistical indicators such as the mean, standard deviation, mean square error and deviation percentage of the actual operation data and the similar design scheme data in the database, and use the K-means clustering algorithm to classify the data and calculate the cluster center to improve the query efficiency. After the data is calculated, it is stored in the database and used to optimize the design scheme.

[0145] S504) Through the deep neural network model, parameter fitting and optimization are performed based on the collected unit operation data. The input parameters include heat source temperature, condensing temperature, evaporation pressure, condensing pressure, turbine expander inlet and outlet enthalpy, cycle thermal efficiency and power generation, and the predicted cycle thermal efficiency, power generation and economic payback period are output. The Bayesian optimization method is used to adaptively adjust the model parameters, and the model is updated once a month to improve the prediction accuracy.

[0146] S505) Based on the cloud computing architecture, an intelligent optimization and recommendation system is constructed. After the user inputs the heat source temperature, cooling method, unit configuration and economic target, the system automatically matches the optimal ORC unit design scheme in the database, and performs optimization calculation based on the gradient boosting decision tree to recommend the optimal unit configuration scheme, including unit configuration, working fluid, expected power generation and economic payback period. At the same time, the similarity between the recommended scheme and the historical optimal scheme is calculated, and the optimization score is output.

[0147] S506) Establish an open database and collaborative optimization platform to support users to upload actual operation data for program optimization. The database uses RESTful API to support data query, upload and optimization calculation, combines blockchain evidence storage technology to ensure data authenticity, and introduces digital twin technology to establish a three-dimensional visualization model of the ORC unit to achieve remote monitoring and optimization.

[0148] S507) Regularly perform database adaptive update and optimization, calculate the impact of new data on the historical optimal solution every 30 days, and trigger model retraining if the deviation between new data and historical data exceeds the threshold. During the optimization process, reinforcement learning + genetic algorithm is used to iteratively optimize the unit design parameters, and each optimization process is recorded to form a database version control mechanism to ensure the continuous optimization of the ORC unit design solution.

[0149] In this embodiment, the design scheme display system outputs the geothermal organic Rankine cycle unit design scheme table as shown in Figure 7-9 shown.

[0150] The geothermal organic Rankine cycle unit design system and method proposed in the present invention can complete thermodynamic cycle design and economic benefit evaluation only with basic information of geothermal resources through a data-driven design library. The database quantifies the differences between different design schemes by using statistical indicators, which can not only evaluate the pros and cons of the schemes, but also optimize the design process. The present invention significantly reduces the design difficulty, improves the design efficiency and economy, and can help designers quickly obtain feasible geothermal power plant design schemes without the need for deep professional background.

[0151] The above is only a preferred embodiment of the present invention, and does not limit the present invention in other forms. Any technician familiar with the profession may use the above disclosed technical content to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the technical solution of the present invention still belongs to the protection scope of the technical solution of the present invention.

Claims

1. A geothermal organic Rankine cycle unit design system, characterized in that: include: Thermodynamic parameter design system, used to calculate the thermodynamic parameters of geothermal organic Rankine cycle; Cycle parameter iteration system, used to determine the optimal cycle parameters of the unit through iterative calculation and evaluate the feasibility of the design scheme; Economic benefit evaluation system, used to evaluate the economic indicators of design solutions; Data processing system, used to summarize various design parameters and compare them with the benchmark solutions in the database to optimize the design solution; Design alternatives display system, used to generate and display detailed comparison of optimal and suboptimal design alternatives.

2. A method for designing a geothermal organic Rankine cycle unit based on the system of claim 1, characterized in that: The following steps are involved: S1. Parameter design of geothermal organic Rankine cycle; S2. Feasibility analysis of geothermal organic Rankine cycle; S3, iterative solution of the optimal heat exchanger area; S4. Economic benefit evaluation of geothermal organic Rankine cycle; S5. Construction of geothermal organic Rankine cycle unit design database.

3. A geothermal organic Rankine cycle unit design method according to claim 2, characterized in that: The geothermal organic Rankine cycle parameter design in step S1 includes the following steps: S101) Input parameters: refrigerant type, ambient temperature and pressure, geothermal resource temperature and state, initial heat exchanger pinch point temperature difference, evaporation temperature, condensation temperature, superheat, subcooling, and efficiency of each mechanical component; S102) calculating by thermodynamic state function: the refrigerant state at two phase transition points inside the evaporator and two phase transition points inside the condenser, and further calculating the refrigerant state at the evaporator outlet and the condenser outlet; the refrigerant state under isentropic conditions at the turbine expander outlet and the working fluid pump outlet, and further calculating the refrigerant state at the turbine expander outlet and the working fluid pump outlet; S103) calculating the geothermal resource temperature and the cooling medium temperature at the evaporator and condenser pinch points determined by the initial heat exchanger pinch point temperature difference, the geothermal resource temperature, and the ambient temperature; S104) calculating the evaporator heat load by using the geothermal resource flow, the geothermal resource temperature at the evaporator narrow point, and the geothermal resource temperature; S105) Calculate the refrigerant flow rate in the cycle based on the evaporator heat load and the thermodynamic state of the refrigerant at the inlet and outlet of the evaporator.

4. A method for designing a geothermal organic Rankine cycle unit according to claim 2, characterized in that: The feasibility analysis of the geothermal organic Rankine cycle in step S2 includes the following steps: S201) Inputting the flow channel depth, flow channel gap, and flow channel pitch of the heat exchanger, preliminarily determining the number of heat exchanger plates and the heat exchanger width, and calculating the geometric parameters of the heat exchanger; S202) calculating the refrigerant density, flow rate and refrigerant side pressure drop at the evaporator inlet through a thermodynamic state function; S203) calculating the refrigerant density, flow rate and refrigerant side pressure drop at the condenser inlet through a thermodynamic state function; S204) calculating the actual thermodynamic state of the refrigerant at the outlet of the evaporator and the condenser through the thermodynamic state function; S205) determining whether there is a possibility of liquid hammer in the working fluid pump, if yes, the feasibility condition is not met, recording that the pressure drop is too large and reporting an error, otherwise proceed to the next step; S206) Iteratively updating the refrigerant flow rate in the cycle; S207) Calculate the enthalpy value error of the evaporator outlet, the refrigerant flow error in the cycle, and the enthalpy value error of the condenser outlet, and determine whether any of the errors is greater than a set threshold. If so, record that the pressure drop is too large and report an error, otherwise go to the next step; S208) Iteratively calculate turbine output power, working fluid pump power consumption, cooling pump power consumption, cycle net output power, geothermal resource return water temperature, cooling water flow and return water temperature, evaporator heat load and condenser heat load, and cycle thermal efficiency.

5. A geothermal organic Rankine cycle unit design method according to claim 2, characterized in that: The iterative solution of the optimal heat exchanger area in step S3 includes the following steps: S301) calculating the initial heat exchanger area according to the initial heat exchanger heat transfer load and the assumed heat flux; S302) calculating the Nusselt number and heat transfer coefficient on the refrigerant side; S303) calculating the water side Reynolds number and Prandtl number, and obtaining the water side heat transfer coefficient; S304) calculating the equivalent heat transfer coefficient in combination with the plate wall thickness, material and heat transfer coefficient; S305) calculating the optimized heat exchanger area according to the heat load and the equivalent heat transfer coefficient; S306) Calculate the relative error between the optimized heat exchanger area and the initial heat exchanger area, and determine whether the relative error is greater than the error setting threshold. If so, proceed to the next step. Otherwise, it is considered to be converged, and the obtained optimized heat exchanger area is the optimal area. S307) Determine whether the heat flux is greater than the heat flux setting threshold. If so, it is considered converged and the optimized heat exchanger area is the optimal area. Otherwise, increase the assumed heat flux and return to step S301 to continue iterative calculation.

6. A method for designing a geothermal organic Rankine cycle unit according to claim 2, characterized in that: The geothermal organic Rankine cycle economic benefit evaluation in step S4 includes the following steps: S401) Calculate geothermal resources, cooling water thermodynamic state, and refrigerant benchmark Status, import and export of each component in geothermal organic Rankine cycle state; S402) Calculating the equipment purchase cost of the turbo expander, working fluid pump, geothermal heat pump, cooling water pump, evaporator and condenser; S403) determining the initial equipment investment of the geothermal organic Rankine cycle unit and the geothermal well drilling cost; S404) Preliminarily determine the annual operation time, expected life, and annual interest rate of the geothermal organic Rankine cycle unit, calculate the capital recovery rate, and calculate the initial investment and operation and maintenance costs during the expected life; S405) Calculate the equivalent operating cost of the computer group, construct a linear algebraic equation group, and calculate the components of the geothermal organic Rankine cycle unit Flow costs; S406) Calculate the net output of geothermal organic Rankine cycle and geothermal resources State-determined loop efficiency; S407) calculating economic indicators including total unit investment, capital payback period and levelized cost of electricity (LCOE); S408) Determine whether the economic indicators meet expectations, if yes, then end, otherwise determine whether the operating conditions can be changed, if yes, return to step S404) to re-determine the relevant operating conditions, if no, report to the data processing system and record in the design database.

7. A geothermal organic Rankine cycle unit design method according to claim 2, characterized in that: The construction of the geothermal organic Rankine cycle unit design database in step S5 includes the following steps: S501) Divide the geothermal resource intervals, use thermodynamic parameter design, cycle parameter iteration, economic benefit evaluation, data processing system calculation design plan, and store it in a relational database and a NoSQL database; S502) Collecting unit operation data through the Internet of Things and SCADA system and storing it in a NoSQL database; S503) Calculate the statistical indicators of the collected data and the design solution data, and optimize the query efficiency through the K-means clustering algorithm; S504) using a deep neural network to perform parameter fitting and optimization, updating the model monthly, and outputting predicted indicators such as thermal efficiency, power generation, and economic payback period; S505) Building an intelligent optimization system based on cloud computing, automatically matching the optimal design solution after the user inputs parameters and calculating the optimization score of the recommended solution; S506) Establish an open database and collaborative optimization platform to support data uploading and solution optimization, and combine blockchain and digital twin technology to achieve data verification and remote monitoring; S507) Update the database regularly. If the deviation between new data and historical data exceeds a threshold, model retraining is triggered, and reinforcement learning and genetic algorithms are used for iterative optimization.

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