A method for predicting annual production of methanol by electrolysis

Abstract

This invention relates to the field of methanol production forecasting technology, and in particular to a method for forecasting the annual output of electro-methanol production; it includes the following steps: S1, building a full-process simulation system for an electro-methanol project and obtaining key technical parameters; S2, calculating key energy consumption indicators based on the obtained key technical parameters; S3, obtaining key energy consumption indicators from multiple data points to form time-series data for new energy power output forecast; S4, dynamically calculating the corresponding real-time methanol output based on the key energy consumption indicators of each data point, while recording the abandoned electricity and purchased electricity; S5, adding up the real-time methanol output of all data points to obtain the annual output; adding up the recorded abandoned electricity and purchased electricity to obtain the annual purchased electricity and annual abandoned electricity; thus improving the accuracy of annual output forecasting for electro-methanol production.

Description

Technical Field

[0001] This invention relates to the field of methanol production forecasting technology, and in particular to a method for forecasting the annual production of electro-methanol. Background Technology

[0002] The production capacity of methanol produced by electricity is constrained by the output characteristics of renewable energy power generation. However, the inherent randomness and intermittency of renewable energy sources such as wind power and photovoltaics lead to significant limitations in capacity assessment models built solely based on equipment technical parameters, resulting in insufficient credibility of capacity assessment results for green methanol projects.

[0003] At present, the electro-methanol project has not yet formed a scientific and complete capacity accounting system. In particular, the lack of a systematic method for accurate annual output calculation directly affects the accuracy of quantitative evaluation of the operational benefits of the green alcohol project.

[0004] Therefore, there is an urgent need to provide a method for predicting the annual output of electro-methanol production, which can improve the accuracy of predicting the annual output of electro-methanol production compared with existing technologies. Summary of the Invention

[0005] This invention addresses the technical problems existing in the prior art and provides a method for predicting the annual output of electro-methanol production.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A method for predicting the annual output of methanol produced by electro-methanol production includes the following steps: S1. Build a full-process simulation system for the electro-methanol project and obtain key technical parameters; S2. Calculate key energy consumption indicators based on the obtained key technical parameters; S3. Obtain key energy consumption indicators from multiple data points to form time-series data for predictive output of new energy sources; S4. Based on the key energy consumption indicators of each data point, dynamically calculate the corresponding real-time methanol production, and record the abandoned electricity and purchased electricity. S5. Add up the real-time methanol production of all data points to get the annual production; add up the recorded abandoned electricity and purchased electricity to get the annual purchased electricity and annual abandoned electricity.

[0008] Furthermore, key technical parameters in step S2 include the electricity consumption of the methanol plant. Electricity consumption per unit of hydrogen produced by an electrolyzer Total electricity consumption per unit mass of methanol produced .

[0009] Furthermore, the electricity consumption of the methanol unit in step S2 is calculated using the following formula: ; In the above formula, Indicates the rated power of the methanol plant. Indicates a unit of time. This indicates the rated output of the methanol plant.

[0010] Furthermore, the power consumption of the electrolyzer in step S2 for producing a unit of hydrogen is specifically calculated using the following formula: ; In the above formula, This indicates the rated power of the electrolytic cell. This indicates the rated output of the electrolytic cell.

[0011] Furthermore, the total electricity consumption for producing one unit mass of methanol in step S2 is calculated using the following formula: ; In the above formula, K represents the amount of hydrogen required to produce one unit mass of methanol.

[0012] Furthermore, S4 specifically includes the following steps: S41. Determine whether the current data point is an adjustable data point. Set an adjustable data point every time threshold. If the current data point is an adjustable data point, proceed to step S42. If it is an unadjustable data point, proceed to step S44. S42. Calculate the real-time methanol production of the current data point, and then proceed to step S43. S43. Obtain the ratio of real-time methanol production calculated in step S42 to the rated production of the methanol unit, set power constraints for the methanol unit, compare the real-time methanol production at the current data point with the power constraints of the methanol unit, and adjust accordingly. S44. Maintain the power of the methanol unit from the previous moment; S45. Update the system status, record the current output, abandoned power, and purchased power, and determine whether the current cycle has ended. All data points constitute one cycle. If the current cycle has not ended, iterate through steps S41-S45. If the current cycle has ended, proceed to step S5.

[0013] Furthermore, the real-time methanol production at the current data point in step S42 is calculated using the following formula: ; In the above formula, This indicates the real-time production volume of methanol. Let i represent the output value of the new energy source at time i, and T represent the unit time. This indicates the amount of energy stored in the battery at the first selected moment. This indicates the mass of hydrogen in the hydrogen storage tank at the first selected moment. This indicates the minimum power adjustment ratio of the methanol synthesis unit. This indicates rounding down. This indicates the rated output of the methanol plant.

[0014] Furthermore, in step S43, the specific method for adjusting according to different situations is as follows: (1) When When the power constraints of the methanol unit are met and the output of new energy sources is within the adjustable range, the power adjustment operation of the methanol unit is carried out. (2) When At this time, it is determined whether the amount of hydrogen stored in the hydrogen storage tank and the energy stored in the energy storage battery meet the minimum production requirements for this cycle. If they do, the hydrogen storage tank and energy storage battery are activated to produce at the minimum power to provide hydrogen for the methanol synthesis unit; if they do not meet the requirements, production is stopped. (3) When At the same time, the new energy output is at full capacity for production, the hydrogen storage tank is storing hydrogen, and the energy storage battery is charging. The energy output of the new energy that exceeds the production needs is first used for hydrogen production and storage in the electrolyzer and then used to charge the energy storage battery. Among them, the power constraint conditions for the methanol plant must meet the following requirement: ; In the above formula, This indicates the current power output of the methanol plant. This indicates the minimum value of the adjustable power range of the methanol plant. This indicates the maximum value of the adjustable power range of the methanol plant.

[0015] Furthermore, the full-process simulation system for the electro-methanol project in step S1 includes a new energy power generation unit, an electrolyzer, a methanol synthesis unit, an energy storage battery system, and a hydrogen storage tank system. The new energy development unit is connected to the energy storage battery system, the electrolyzer, and the methanol synthesis device, respectively. The energy storage battery system is connected to the electrolyzer and the methanol synthesis device, respectively. The electrolyzer is connected to the input end of the hydrogen storage tank system, and the output end of the hydrogen storage tank system is connected to the methanol synthesis device.

[0016] Furthermore, the constraints on the operation of the electrolyzer for hydrogen storage in the hydrogen storage tank, and the constraints on the charging and discharging of the energy storage battery are specifically as follows: (1) The hydrogen storage rate satisfies the following constraint: ; In the above formula, Indicates the hydrogen storage rate, This indicates the maximum mass of hydrogen in the hydrogen storage tank at the selected time. Indicates the maximum hydrogen storage rate; (2) The charging rate satisfies the following constraint: ; ; In the above formula, Indicates the charging rate. This indicates the maximum capacity of the energy storage battery. This indicates the initial charge in the energy storage at the previous moment. This represents the change in energy storage at the previous moment. Indicates the maximum charging rate of the energy storage. Represents binary variables. This indicates that it is charging. The time indicates that a discharge is in progress; (3) The discharge rate satisfies the following constraint: ; ; In the above formula, G represents the discharge rate, and G represents the maximum discharge rate of the stored energy. The following formula can be used to calculate: ; In the above formula, This indicates the charging rate at the previous moment. This represents the discharge rate at the previous moment.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) This invention breaks through the limitations of the traditional static parameterized capacity assessment paradigm. By integrating energy storage systems, hydrogen storage systems, and methanol plant power regulation systems, it implements a multi-system collaborative operation optimization strategy. It couples and solves dynamic parameters with time-series characteristics, such as the new energy output prediction model, the dynamic characteristics of the energy storage / hydrogen storage system, and the unadjustable power cycle of the methanol plant, to construct a single-hour capacity calculation model. By superimposing the single-hour predicted values ​​over time, the project's predicted annual output can be obtained. This model effectively alleviates the problem of inaccurate capacity assessment caused by the intermittent output characteristics of wind power / photovoltaics.

[0018] (2) This invention differs from existing calculation methods based on static parameters. The aforementioned calculation method integrates energy storage systems, hydrogen storage systems, and methanol plant power regulation systems to implement a multi-system collaborative operation optimization strategy. It couples the power regulation characteristics of hydrogen storage, energy storage, and methanol synthesis units with dynamic parameters exhibiting time-series characteristics, such as the fluctuation characteristics of new energy output. Using the power regulation time interval of the methanol plant (typically 4-8 hours) as the basic calculation cycle, a single-hour capacity calculation model is constructed. By time-series superposition of the single-hour predicted values, the project's annual capacity prediction can be accurately derived. This dynamic annual production calculation method can help enterprises more accurately predict annual production based on past new energy output and selected equipment parameters. Attached Figure Description

[0019] Figure 1 This is a flowchart of the present invention.

[0020] Figure 2 This is a flowchart of the dynamic calculation of output in this invention.

[0021] Figure 3 This is a schematic diagram of the full-process simulation system for the electro-methanol production project of this invention. Detailed Implementation

[0022] The technical solution of the present invention will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are not all embodiments of the present invention. All other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0023] like Figure 1 , Figure 2 As shown, this invention provides a method for predicting the annual output of electro-methanol production, comprising the following steps: S1. Establish a full-process simulation system for the electro-methanol project. This system includes: a new energy power generation unit, an electrolyzer, a methanol synthesis unit, an energy storage battery system, and a hydrogen storage tank system. Key technical parameters will be obtained, including those related to the new energy side, the electrolyzer, and the methanol unit.

[0024] like Figure 3 As shown, the new energy development unit is connected to the energy storage battery system, the electrolyzer, and the methanol synthesis unit, respectively. The energy storage battery system is connected to the electrolyzer and the methanol synthesis unit, respectively. The electrolyzer is connected to the input end of the hydrogen storage tank system, and the output end of the hydrogen storage tank system is connected to the methanol synthesis unit.

[0025] S2. Based on the key technical parameters obtained in step S1, calculate the key energy consumption indicators, including the electricity consumption of the methanol unit, the electricity consumption of the electrolyzer to produce one unit of hydrogen, and the total electricity consumption to produce one unit of methanol. Specifically: (1) The electricity consumption of the methanol plant can be calculated using the following formula: ; In the above formula, This indicates the electricity consumption of the methanol plant. Indicates the rated power of the methanol plant. Indicates a unit of time. This indicates the rated output of the methanol plant.

[0026] (2) Calculate the power consumption of the electrolyzer to produce one unit of hydrogen using the following formula: ; In the above formula, This indicates the power consumption of the electrolyzer to produce one unit of hydrogen. This indicates the rated power of the electrolytic cell. This indicates the rated output of the electrolytic cell.

[0027] (3) Calculate the total electricity consumption for producing one unit mass of methanol using the following formula: ; In the above formula, K represents the total electricity consumption for producing one unit mass of methanol, and K represents the amount of hydrogen required to produce one unit mass of methanol.

[0028] S3. Obtain the time series data of the predicted output of new energy in a typical year at the project location. The time resolution is 1 hour, with a total of 8760 data points. The interval between adjacent data points is one hour. Here, i is set as the time index, and i can be 1 to 8760.

[0029] S4. Dynamically calculate the methanol production for each data point, with one data point representing one hour; specifically including the following steps: S41. Determine whether the data point is an adjustable data point. Set a time threshold. Every time threshold, set the data point as an adjustable data point. Data points within the time threshold are non-adjustable data points. The time threshold can be 4h or 8h. If the current data point is an adjustable data point, proceed to step S42. If it is a non-adjustable data point, proceed to step S44.

[0030] S42. Calculate the real-time methanol production rate for the current data point, then proceed to step S43. The real-time methanol production rate is calculated using the following formula: ; In the above formula, This indicates the real-time production volume of methanol. This represents the output value of the new energy source at time i. This indicates the amount of energy stored in the battery at the first selected moment. This indicates the mass of hydrogen in the hydrogen storage tank at the first selected moment. This indicates the minimum power adjustment ratio of the methanol synthesis unit. This indicates rounding down to the nearest integer.

[0031] S43. Obtain the ratio of the real-time methanol production calculated in step S42 to the rated production of the methanol unit. Compare this ratio with the power constraints of the methanol unit and adjust accordingly, specifically: (1) When When the power constraints of the methanol unit are met and the output of new energy sources is within the adjustable range, the power adjustment operation of the methanol unit is carried out.

[0032] (2) When At that time, it is determined whether the amount of hydrogen stored in the hydrogen storage tank and the energy stored in the energy storage battery meet the minimum production requirements for this cycle. If they do, the hydrogen storage tank and energy storage battery are activated to produce at the minimum power to provide hydrogen for the methanol synthesis unit; if they do not meet the requirements, production is stopped.

[0033] (3) When At the same time, the new energy output is at full capacity for production, the hydrogen storage tank is storing hydrogen, and the energy storage battery is charging. The energy output of the new energy source exceeding the production capacity is first used for hydrogen production and storage in the electrolyzer and then used to charge the energy storage battery.

[0034] The following formula must be satisfied under the power constraints of the methanol plant: ; In the above formula, This indicates the current power output of the methanol plant. This indicates the minimum value of the adjustable power range of the methanol plant. This indicates the maximum value of the adjustable power range of the methanol plant.

[0035] The constraints on the operation of the electrolyzer for hydrogen storage in the hydrogen storage tank, and the constraints on the charging and discharging of the energy storage battery are as follows: The hydrogen storage rate satisfies the following constraint: ; In the above formula, Indicates the hydrogen storage rate, This indicates the maximum mass of hydrogen in the hydrogen storage tank at the selected time. This indicates the maximum hydrogen storage rate.

[0036] The charging rate satisfies the following constraint: ; ; In the above formula, Indicates the charging rate. This indicates the maximum capacity of the energy storage battery. This indicates the initial charge in the energy storage at the previous moment. This represents the change in energy storage at the previous moment. Indicates the maximum charging rate of the energy storage. Represents binary variables. This indicates that it is charging. The time indicates that a discharge is in progress.

[0037] The discharge rate satisfies the following constraint: ; ; In the above formula, G represents the discharge rate, and G represents the maximum discharge rate of the stored energy.

[0038] The following formula can be used to calculate: ; In the above formula, This indicates the charging rate at the previous moment. This represents the discharge rate at the previous moment.

[0039] S44. Maintain the power output of the previous moment. When the output of new energy sources is insufficient, use hydrogen storage tanks, energy storage batteries, and purchased electricity for production. When the output of new energy sources is sufficient, perform hydrogen storage and energy storage charging.

[0040] S45. Update the system status, record the current output, abandoned power, and purchased power, and determine whether the current cycle has ended. A cycle is 8760 hours. If the current cycle has not ended, iterate through steps S41-S45. If the current cycle has ended, proceed to step S5.

[0041] S5. Calculate the annual output, and simultaneously record the annual purchased electricity volume and the annual abandoned electricity volume. The annual output is calculated using the following formula: ; In the above formula, Indicates annual output. This represents the real-time methanol production at time i.

[0042] The total annual electricity purchase is the sum of the electricity purchased from external networks over all time steps.

[0043] The total annual abandoned power is the sum of the renewable energy output that is forced to be abandoned due to its inability to be absorbed or stored over all time steps.

[0044] This invention breaks through the limitations of traditional static parameterized capacity assessment paradigms by integrating energy storage systems, hydrogen storage systems, and methanol plant power regulation systems to implement a multi-system collaborative operation optimization strategy. It couples and solves time-series dynamic parameters such as the new energy output prediction model, the dynamic characteristics of the energy / hydrogen storage system, and the unadjustable power cycle of the methanol plant to construct a single-hour capacity calculation model. By superimposing the single-hour predicted values ​​over time, the project's predicted annual output can be obtained. This model effectively alleviates the inaccurate capacity assessment problem caused by the intermittent output characteristics of wind / solar power.

[0045] Unlike existing static parameter-based calculation methods, the above method integrates energy storage systems, hydrogen storage systems, and methanol plant power regulation systems to implement a multi-system collaborative operation optimization strategy. It couples the power regulation characteristics of hydrogen storage, energy storage, and methanol synthesis units with dynamic parameters exhibiting time-series characteristics, such as the fluctuation characteristics of new energy output. Using the power regulation time interval of the methanol plant (typically 4-8 hours) as the basic calculation period, a single-hour capacity calculation model is constructed. By overlaying the single-hour predicted values ​​over time, the project's annual capacity prediction can be accurately derived. This dynamic annual output calculation method helps companies more accurately predict annual output based on historical new energy output and selected equipment parameters.

[0046] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention do not depart from the essence and scope of the technical solution of the present invention.

Claims

1. A method for predicting annual production of electro-methanol production, characterized by, Includes the following steps: S1. Build a full-process simulation system for the electro-methanol project and obtain key technical parameters; S2. Calculate key energy consumption indicators based on the obtained key technical parameters; S3. Obtain key energy consumption indicators from multiple data points to form time-series data for predictive output of new energy sources; S4. Based on the key energy consumption indicators of each data point, dynamically calculate the corresponding real-time methanol production, and record the abandoned electricity and purchased electricity. S5. Add up the real-time methanol production of all data points to get the annual production; add up the recorded abandoned electricity and purchased electricity to get the annual purchased electricity and annual abandoned electricity.

2. The method for predicting the annual output of electro-methanol production according to claim 1, characterized in that, The key technical parameters in S2 include the power consumption of the methanol device , the power consumption of the electrolytic cell for producing unit hydrogen , and the total power consumption for producing unit mass of methanol .

3. The method of claim 2, wherein the method is characterized by: The electricity consumption of the methanol unit in step S2 is calculated using the following formula: ； In the above formula, represents the rated power of the methanol plant, represents the unit of time, represents the rated production of the methanol plant.

4. The method for predicting the annual output of electro-methanol production according to claim 3, characterized in that, The power consumption for producing a unit of hydrogen in the electrolyzer in step S2 is calculated using the following formula: ； In the above formula, This indicates the rated power of the electrolytic cell. This indicates the rated output of the electrolytic cell.

5. The method for predicting the annual output of electro-methanol production according to claim 4, characterized in that, The total electricity consumption for producing one unit mass of methanol in step S2 is calculated using the following formula: ； In the above formula, K represents the amount of hydrogen required to produce one unit mass of methanol.

6. The method for predicting the annual output of electro-methanol production according to claim 2, characterized in that, S4 specifically includes the following steps: S41. Determine whether the current data point is an adjustable data point. Set an adjustable data point every time threshold. If the current data point is an adjustable data point, proceed to step S42. If it is an unadjustable data point, proceed to step S44. S42. Calculate the real-time methanol production of the current data point, and then proceed to step S43. S43. Obtain the ratio of real-time methanol production calculated in step S42 to the rated production of the methanol unit, set power constraints for the methanol unit, compare the real-time methanol production at the current data point with the power constraints of the methanol unit, and adjust accordingly. S44. Maintain the power of the methanol unit from the previous moment; S45. Update the system status, record the current output, abandoned power, and purchased power, and determine whether the current cycle has ended. All data points constitute one cycle. If the current cycle has not ended, iterate through steps S41-S45. If the current cycle has ended, proceed to step S5.

7. The method for predicting the annual output of electro-methanol production according to claim 6, characterized in that, In step S42, the real-time methanol production at the current data point is calculated using the following formula: ； In the above formula, This indicates the real-time production volume of methanol. Let i represent the output value of the new energy source at time i, and T represent the unit time. This indicates the amount of energy stored in the battery at the first selected moment. This indicates the mass of hydrogen in the hydrogen storage tank at the first selected moment. This indicates the minimum power adjustment ratio of the methanol synthesis unit. Indicates rounding down. This indicates the rated output of the methanol plant.

8. The method for predicting the annual output of electro-methanol production according to claim 7, characterized in that, In step S43, the specific method for adjusting according to different situations is as follows: (1) When When the power constraints of the methanol unit are met and the output of new energy sources is within the adjustable range, the power adjustment operation of the methanol unit is carried out. (2) When At this time, it is determined whether the amount of hydrogen stored in the hydrogen storage tank and the energy stored in the energy storage battery meet the minimum production requirements for this cycle. If they do, the hydrogen storage tank and energy storage battery are activated to produce at the minimum power to provide hydrogen for the methanol synthesis unit; if they do not meet the requirements, production is stopped. (3) When At the same time, the new energy output is at full capacity for production, the hydrogen storage tank is storing hydrogen, and the energy storage battery is charging. The energy output of the new energy that exceeds the production needs is first used for hydrogen production and storage in the electrolyzer and then used to charge the energy storage battery. Among them, the power constraint conditions for the methanol plant must meet the following requirement: ； In the above formula, This indicates the current power output of the methanol plant. This indicates the minimum value of the adjustable power range of the methanol plant. This indicates the maximum value of the adjustable power range of the methanol plant.

9. The method for predicting the annual output of electro-methanol production according to claim 7, characterized in that, The full-process simulation system for the electro-methanol project in step S1 includes a new energy power generation unit, an electrolyzer, a methanol synthesis unit, an energy storage battery system, and a hydrogen storage tank system. The new energy development unit is connected to the energy storage battery system, the electrolyzer, and the methanol synthesis device, respectively. The energy storage battery system is connected to the electrolyzer and the methanol synthesis device, respectively. The electrolyzer is connected to the input end of the hydrogen storage tank system, and the output end of the hydrogen storage tank system is connected to the methanol synthesis device.

10. The method for predicting the annual output of electro-methanol production according to claim 9, characterized in that, The constraints on the operation of the electrolyzer for hydrogen storage in the hydrogen storage tank, and the constraints on the charging and discharging of the energy storage battery are as follows: (1) The hydrogen storage rate satisfies the following constraint: ； In the above formula, Indicates the hydrogen storage rate, This indicates the maximum mass of hydrogen in the hydrogen storage tank at the selected time. Indicates the maximum hydrogen storage rate; (2) The charging rate satisfies the following constraint: ； ； In the above formula, Indicates the charging rate. This indicates the maximum capacity of the energy storage battery. This indicates the initial charge in the energy storage at the previous moment. This represents the change in energy storage at the previous moment. Indicates the maximum charging rate of the energy storage. Represents binary variables. This indicates that it is charging. The time indicates that a discharge is in progress; (3) The discharge rate satisfies the following constraint: ； ； In the above formula, G represents the discharge rate, and G represents the maximum discharge rate of the stored energy. The following formula can be used to calculate: ； In the above formula, This indicates the charging rate at the previous moment. This represents the discharge rate at the previous moment.

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