A real-time calculation method for carbon assets of thermal power plants

Abstract

The present invention relates to a real-time calculation method for carbon assets in thermal power plants. Without the need for a new carbon dioxide emissions measurement device, the method can calculate the changes in the carbon assets of the enterprise during the operation of the generator set in real time based on the statistical data of the daily production of the generator set and establish a carbon asset library, making the enterprise's carbon asset management more convenient, standardized and intuitive. The calculated carbon emission values have a small deviation from the actual statistical values, and the calculation method has high accuracy. Furthermore, the carbon asset library can also provide a data basis for power generation enterprises to deeply adjust their quotations and future production strategies, guide enterprises to purchase / sell quotas in advance, reduce / increase annual carbon quota compliance expenditures / income, and avoid enterprises being in a passive trading position.

Description

Technical Field

[0001] The present invention relates to the field of wind turbine vibration control, and in particular to a wind turbine tower vibration reduction method based on a stiffness-adjustable dynamic vibration absorber. Background Art

[0002] With the growing popularity of the national carbon trading market and the continuous improvement of market policies and regulations, the majority of thermal power companies have now been included in the market. Power generation companies included in the carbon trading market are required to regularly settle their carbon emissions each year. Failure to comply on time will result in strict assessments and penalties.

[0003] However, carbon emissions from thermal power plants are currently subject to dynamic fluctuations, influenced by a range of factors, including unit load, coal type, and unit energy consumption. Power generation companies lack real-time access to carbon asset status and can only rely on periodic verification or calculations based on coal consumption. Furthermore, carbon allowances are collected and verified annually, leaving power generation companies in a passive trading position, purchasing or selling allowances only after carbon emissions verification. Therefore, improvements and innovations are imperative. Summary of the Invention

[0004] In view of the above situation, in order to overcome the shortcomings of the existing technology, the purpose of the present invention is to provide a real-time calculation method for carbon assets of thermal power plants, which can effectively solve the problem of real-time calculation of changes in the carbon assets of enterprises when the generator sets are running.

[0005] The technical solution adopted in the present invention is:

[0006] A method for real-time calculation of carbon assets of a thermal power plant comprises the following steps:

[0007] The first step is to calculate the turbine heat rate HR based on the generator set operating parameters. The formula is as follows:

[0008]

[0009] Where: HR-turbine heat rate, kJ / kWh; W ms -Main steam flow, t / h; h ms - Main steam enthalpy, kJ / kg; W hr -Hot reheat steam flow, t / h; h hr -Hot reheat steam enthalpy, kJ / kg; W cr -cold reheat steam flow, t / h; h cr -cold reheat steam enthalpy, kJ / kg; W fw -Final water flow, t / h; h fw -Final feed water enthalpy, kJ / kg; W rh -Reheater desuperheating water flow, t / h; h rh- Reheater desuperheating water enthalpy, kJ / kg; W sh -Superheater desuperheating water flow, t / h; h sh -Superheater desuperheating water enthalpy, kJ / kg; P-generator output power, MW;

[0010] The second step is to calculate the carbon dioxide emission factor based on the coal test results. The formula is as follows:

[0011]

[0012]

[0013] Where: EF is the emission factor of coal combustion, tCO2 / GJ;

[0014] CC is the carbon content per unit calorific value of coal, tC / GJ;

[0015] C ar is the received elemental carbon content of the coal, tC / t;

[0016] NCV ar is the received lower calorific value of coal, GJ / t;

[0017] OF is the carbon oxidation rate of the coal, %;

[0018] The third step is to calculate the heat consumption Q of the steam turbine once per second. s , the formula is as follows:

[0019]

[0020] Where: Q s is the heat consumption of the steam turbine per second, kJ / kWh; P is the generator output power, kW;

[0021] Step 4: Calculate the heat consumption Q of the steam turbine in one hour h , the formula is as follows

[0022]

[0023] Where n = 3600; Q h is the heat consumption of the steam turbine in one hour, kJ;

[0024] Step 5: Calculate carbon emissions C within one hour mh , the formula is as follows:

[0025]

[0026] Where C mhis the carbon emissions of the unit within one hour, t; δ is the boiler efficiency, %; 0.99 is the pipeline efficiency, which is a fixed value; Step 6, calculate the carbon quota of power supply within one hour A according to the quota allocation method in the "Guidelines for the Accounting and Reporting of Greenhouse Gas Emissions for Enterprises - 2022 Revised Edition of Power Generation Facilities" (hereinafter referred to as the Guidelines) issued by the General Office of the Ministry of Ecology and Environment eh , the formula is as follows:

[0027] A eh =P×B e ×F l ×F f

[0028]

[0029] Where: n = 3600; A eh is the carbon quota of the unit's power supply within one hour, tCO2; P is the generator's export power, Q h Power supply to the unit, MWh; B e F is the power supply reference value of the category to which the unit belongs; l F is the unit cooling method correction factor; f is the unit load correction factor;

[0030] The seventh step is to compare the calculated carbon emissions within one hour with the carbon quota of power supply within one hour. If the carbon emissions are less than the carbon quota of power supply, the difference in emissions will be included in the carbon asset library of the factory; if the carbon emissions are greater than the carbon quota of power supply, it will be included in the carbon asset library of the factory as a negative value; when the quota in the carbon asset library is positive, it means that the company's carbon emissions to date are less than the quota, and the quota in the asset library can be used for trading. The company can choose to sell in advance when the quota price is high; when the quota in the carbon asset library is negative, it means that the company's carbon emissions to date are greater than the quota and it needs to purchase quotas. The company can choose to buy in advance when the quota price is low to reduce carbon emission costs.

[0031] The method presented here is simple and rational. During the operation of a coal-fired unit's steam turbine, the turbine converts steam energy into mechanical energy, driving the generator to output electricity. Therefore, calculating the heat consumed by the unit's power generation from the turbine side is more accurate and reliable than other statistical data. The heat consumed by the turbine side can be inferred from the heat generated by burning fuel in the boiler. Based on the calorific value of the coal in the medium test report, the total heat consumed is divided by the calorific value of the fuel to determine the amount of fuel burned by the unit. Based on the carbon content in the fuel test data, carbon dioxide emissions can be calculated by multiplying the fuel amount by the carbon content. However, in the actual production of coal-fired power generation units, coal consumption statistics are relatively crude and inaccurate. Therefore, estimating carbon emissions based on the actual heat consumed by the turbine is more accurate. This method can provide accurate data for the refined management of enterprises' carbon assets, taking the initiative in the carbon trading market and preparing for carbon trading compliance.

[0032] The method of the present invention provides a real-time carbon asset analysis method, which does not require a new carbon dioxide emission measurement device. Based on the statistical data of the daily production of the generator set, the changes in the carbon assets of the enterprise when the generator set is running can be calculated in real time and a carbon asset library can be established, making the enterprise's carbon asset management more convenient, standardized and intuitive. The calculated carbon emission values have a small deviation from the actual statistical values, and the calculation method is highly accurate. Furthermore, the carbon asset library can also provide a data basis for power generation companies to deeply adjust their quotations and future production strategies, guide companies to buy / sell quotas in advance, reduce / increase annual carbon quota compliance expenditures / income, and avoid companies being in a passive trading position. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 Flowchart of the present invention. DETAILED DESCRIPTION

[0034] The specific implementation of the present invention is further described in detail below with reference to the accompanying drawings and examples.

[0035] like Figure 1 As shown, the present invention provides a real-time calculation method for carbon assets of a thermal power plant, comprising the following steps:

[0036] The first step is to calculate the turbine heat rate HR based on the generator set operating parameters. The formula is as follows:

[0037]

[0038] Where: HR-turbine heat rate, kJ / kWh; W ms -Main steam flow, t / h; h ms - Main steam enthalpy, kJ / kg; W hr -Hot reheat steam flow, t / h; h hr -Hot reheat steam enthalpy, kJ / kg; W cr-cold reheat steam flow, t / h; h cr -cold reheat steam enthalpy, kJ / kg; W fw -Final water flow, t / h; h fw -Final feed water enthalpy, kJ / kg; W rh -Reheater desuperheating water flow, t / h; h rh - Reheater desuperheating water enthalpy, kJ / kg; W sh -Superheater desuperheating water flow, t / h; h sh - Superheater desuperheating water enthalpy, kJ / kg; P-generator outlet power, MW; the above parameters can be obtained from the turbine DCS system;

[0039] The second step is to calculate the carbon dioxide emission factor based on the coal test results. The formula is as follows:

[0040]

[0041]

[0042] Where: EF is the emission factor of coal combustion, tCO2 / GJ;

[0043] CC is the carbon content per unit calorific value of the coal, tC / GJ, obtained from the coal analysis report;

[0044] C ar is the received elemental carbon content of the coal, tC / t, obtained from the coal analysis report;

[0045] NCV ar is the received lower calorific value of the coal, GJ / t, obtained from the coal analysis report;

[0046] OF is the carbon oxidation rate of the coal, %, obtained from the coal test report;

[0047] The third step is to calculate the heat consumption Q of the steam turbine once per second. s , the formula is as follows:

[0048]

[0049] Where: Q s is the heat consumption of the steam turbine per second, kJ / kWh; P is the generator output power, kW;

[0050] Step 4: Calculate the heat consumption Q of the steam turbine in one hour h , the formula is as follows

[0051]

[0052] Where n = 3600; Q h is the heat consumption of the steam turbine in one hour, kJ;

[0053] Step 5: Calculate carbon emissions C within one hour mh , the formula is as follows:

[0054]

[0055] Where C mh is the carbon emission of the unit in one hour, t; δ is the boiler efficiency, %, obtained from the unit boiler efficiency test report; 0.99 is the pipeline efficiency, which is a fixed value;

[0056] Step 6: Calculate the carbon quota of power supply within one hour according to the quota allocation method in the "Guidelines for Enterprise Greenhouse Gas Emissions Accounting and Reporting - Power Generation Facilities 2022 Revised Edition" (hereinafter referred to as the "Guidelines") issued by the General Office of the Ministry of Ecology and Environment. eh , the formula is as follows:

[0057] A eh =P×B e ×F l ×F f

[0058]

[0059] Where: n = 3600; A eh is the carbon quota of the unit's power supply within one hour, tCO2; P is the generator's export power, Q h Power supply to the unit, MWh; B e The power supply reference value for the unit category can be found in the guide; F l F is the correction factor for the unit cooling method, 1 for water cooling and 1.05 for air cooling; f is the unit load correction factor;

[0060] The load correction coefficients of units in each load section need to have different values, as shown in the table:

[0061] Unit load factor during calculation period Correction factor P≥85％ 1 80％＜P≤85％ 1+0.0014*(85-100P) 75％＜P≤80％ 1.007+0.0016*(80-100P) P≤75％ <![CDATA[1.015 (16-20*P) ]]>

[0062] The seventh step is to compare the calculated carbon emissions within one hour with the carbon quota of power supply within one hour. If the carbon emissions are less than the carbon quota of power supply, the difference in emissions will be included in the carbon asset library of the factory; if the carbon emissions are greater than the carbon quota of power supply, it will be included in the carbon asset library of the factory as a negative value; when the quota in the carbon asset library is positive, it means that the company's carbon emissions to date are less than the quota, and the quota in the asset library can be used for trading. The company can choose to sell in advance when the quota price is high; when the quota in the carbon asset library is negative, it means that the company's carbon emissions to date are greater than the quota and it needs to purchase quotas. The company can choose to buy in advance when the quota price is low to reduce carbon emission costs.

[0063] The present invention has achieved good technical effects through practical application. Taking a 1000MW coal-fired power generation unit as an example, the calculated values and measured values are shown in the following table:

[0064] Table 1 Calculated and measured values

[0065]

[0066] It can be clearly seen from the above situation that the deviation between the calculated value and the measured value is less than 0.5%, which meets the accuracy requirements and proves that the method is feasible and reliable.

Claims

1. A real-time calculation method for carbon assets of thermal power plants, characterized in that: The following steps are involved: The first step is to calculate the turbine heat rate HR based on the generator set operating parameters. The formula is as follows: Where: HR-turbine heat rate, kJ / kWh; W ms -Main steam flow, t / h; h ms - Main steam enthalpy, kJ / kg; W hr -Hot reheat steam flow, t / h; h hr -Hot reheat steam enthalpy, kJ / kg; W cr -cold reheat steam flow, t / h; h cr -cold reheat steam enthalpy, kJ / kg; W fw -Final water flow, t / h; h fw -Final feed water enthalpy, kJ / kg; W rh -Reheater desuperheating water flow, t / h; h rh - Reheater desuperheating water enthalpy, kJ / kg; W sh -Superheater desuperheating water flow, t / h; h sh -Superheater desuperheating water enthalpy, kJ / kg; P-generator output power, MW; The second step is to calculate the carbon dioxide emission factor based on the coal test results. The formula is as follows: Where: EF is the emission factor of coal combustion, tCO2 / GJ; CC is the carbon content per unit calorific value of coal, tC / GJ; C ar is the received elemental carbon content of the coal, tC / t; NCV ar is the received lower calorific value of coal, GJ / t; OF is the carbon oxidation rate of the coal, %; The third step is to calculate the heat consumption Q of the steam turbine once per second. s , the formula is as follows: Where: Q s is the heat consumption of the steam turbine per second, kJ / kWh; P is the generator output power, kW; Step 4: Calculate the heat consumption Q of the steam turbine in one hour h , the formula is as follows Where n = 3600; Q h is the heat consumption of the steam turbine in one hour, kJ; Step 5: Calculate carbon emissions C within one hour mh , the formula is as follows: Where C mh is the carbon emissions of the unit within one hour, t; δ is the boiler efficiency, %; 0.99 is the pipeline efficiency, which is a fixed value; Step 6: Calculate the carbon quota for power supply within one hour according to the quota allocation method in the "Guidelines for Enterprise Greenhouse Gas Emissions Accounting and Reporting - Power Generation Facilities 2022 Revised Edition" issued by the General Office of the Ministry of Ecology and Environment. eh , the formula is as follows: A eh =P×B e ×F l ×F f Where: n = 3600; A eh is the carbon quota of the unit's power supply within one hour, tCO2; P is the generator's export power, Q h Power supply to the unit, MWh; B e F is the power supply reference value of the category to which the unit belongs; l F is the unit cooling method correction factor; f is the unit load correction factor; The seventh step is to compare the calculated carbon emissions within one hour with the carbon quota of power supply within one hour. If the carbon emissions are less than the carbon quota of power supply, the difference in emissions will be included in the carbon asset library of the factory; if the carbon emissions are greater than the carbon quota of power supply, it will be included in the carbon asset library of the factory as a negative value; when the quota in the carbon asset library is a positive value, it means that the company's carbon emissions to date are less than the quota, and the quota in the asset library can be used for trading; when the quota in the carbon asset library is a negative value, it means that the company's carbon emissions to date are greater than the quota, and the quota needs to be purchased.

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