A coal power molten salt heat storage system real-time dynamic heat supply carbon emission intensity calculation method

Abstract

This invention discloses a method for calculating the real-time dynamic carbon emission intensity of a coal-fired power plant molten salt thermal energy storage system, relating to the field of coal-fired power plant heating technology. This invention innovatively constructs a real-time dynamic calculation formula based on the actual operating state of the system. It can dynamically calculate the true carbon emission intensity of the heating process at different times based on the heat storage / release behavior of the molten salt thermal energy storage system and the unit's operating conditions, significantly improving the scientific rigor and accuracy of the calculation results and providing a reliable methodological foundation for precise carbon tracking and measurement. This invention also comprehensively considers the influence of natural factors, further considering the impact of external environmental heat exchange on the system beyond the characteristics of the thermal system itself, and incorporating this factor into the calculation framework. This ensures that the final calculated carbon emission intensity not only reflects the carbon emission characteristics of the heat source but also integrates the natural heat dissipation of the molten salt system itself, guaranteeing the accuracy and reliability of the assessment results.

Description

Technical Field

[0001] This invention relates to the field of coal-fired power heating technology, and in particular to a method for calculating the carbon emission intensity of a coal-fired power molten salt thermal storage system in real time. Background Technology

[0002] As my country's energy structure transformation accelerates and the proportion of new energy installed capacity continues to increase, the volatility, randomness, and uncontrollable output of new energy sources such as photovoltaics and wind power have prevented them from becoming reliable alternatives to electricity supply. This results in large-scale curtailment of wind and solar power, leading to decreased grid stability. Ensuring power supply and facilitating the integration of new energy sources are the two major challenges facing the development of the new power system. Coal-fired power units still bear a significant portion of the peak-shaving load during the energy structure transformation process. However, some coal-fired power units are combined heat and power (CHP) units, inherently possessing strong heat-electricity coupling characteristics. Power generation and heating are mutually constrained. During periods of low grid load, they often cannot participate in deep peak shaving due to the need to ensure heating demand, while during periods of high grid load, they cannot operate at full capacity due to the steam consumed for heating.

[0003] By storing and releasing heat at appropriate times through molten salt thermal storage systems, thermoelectric decoupling is achieved, resolving the pain point of conflict between power supply peak regulation and heating guarantee of thermal power units, and significantly improving the bidirectional peak regulation capability of power supply while ensuring heating demand.

[0004] Currently, there is no clear method for calculating the carbon emission intensity of coal-fired power molten salt thermal storage systems. To meet the needs of accurate carbon emission tracking, it is of great significance to propose a method, equipment, and storage medium for calculating the real-time dynamic carbon emission intensity of coal-fired power molten salt thermal storage systems. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a method for calculating the carbon emission intensity of a coal-fired molten salt thermal energy storage system in real time.

[0006] This invention is achieved through the following technical solution:

[0007] A method for calculating the carbon emission intensity of a coal-fired molten salt thermal storage system under real-time dynamic heating, specifically including the following steps:

[0008] S1. Calculate the real-time carbon emissions of the coal-fired power unit based on any of the following methods: fuel consumption data, flue gas online monitoring data, or the fitting relationship between the thermal load output and carbon emissions of the coal-fired power unit.

[0009] S2. Based on the allocation ratio of the total heat supply of coal-fired power units for power generation, direct external heat supply, and molten salt thermal storage, determine the proportion of the output of coal-fired power units for direct external heat supply and the proportion of the output for molten salt thermal storage.

[0010] S3. Combine the real-time carbon emissions obtained from S1 and the output ratios obtained from S2 to calculate the carbon emission intensity of direct heating from coal-fired power units and the carbon emission intensity of molten salt thermal storage.

[0011] S4. Perform dynamic carbon carrying tracking on the molten salt thermal storage system. Calculate the heat and carbon content after thermal storage based on the carbon emission intensity of the molten salt thermal storage stage and the increase in heat storage and carbon after thermal storage. Calculate the carbon carrying rate per unit of heat after thermal storage based on the heat and carbon content. Combine the duration of the static phase of the molten salt thermal storage system to calculate the natural heat exchange during the static phase. When entering the heat release phase, acquire the released heat. Subtract the natural heat exchange and the released heat from the heat stored in the tank after thermal storage to obtain the heat stored in the tank after heat release. Divide the carbon content after thermal storage by the heat stored after deducting the natural heat exchange to calculate the carbon carrying rate per unit of heat in the heat release phase. Further calculate the carbon content in the tank after heat release and the carbon carrying rate per unit of heat in the system. If the next phase continues to release heat, use the carbon carrying rate per unit of heat after this heat release as the carbon carrying rate per unit of heat in the next phase of heat release. If the next phase begins thermal storage, return to the calculation stage of the heat storage increment and recalculate.

[0012] S5. Real-time acquisition of the flow rate, pressure, and temperature parameters of the external heating steam of the coal-fired power plant molten salt thermal storage system, and calculation of the current heating flow rate;

[0013] S6. Determine the current heating mode, which includes heating by coal-fired power units alone, heating by molten salt thermal storage system alone, and heating by both. Calculate the real-time dynamic heating carbon emission intensity of the coal-fired power molten salt thermal storage system at this moment under the current heating mode based on the calculation results of steps S3, S4, and S5.

[0014] The specific details of step S1 are as follows:

[0015] (a) The calculation of real-time carbon emissions from coal-fired power units based on fuel consumption data is as follows:

[0016] The real-time carbon emissions of coal-fired power units are calculated based on the carbon oxidation rate of fuel carbon, the carbon content of the basic elements, and the fuel consumption of the unit. The carbon oxidation rate of fuel carbon is obtained by calculating the average carbon content of ash and slag, which is calculated based on the mass fraction of slag in the total ash of fuel, the mass fraction of fly ash in the total ash of fuel, the mass fraction of combustibles in slag, and the mass fraction of combustibles in fly ash.

[0017] (b) Calculate the real-time carbon emissions of the coal-fired power unit based on the online flue gas monitoring data, as follows:

[0018] It is calculated based on the density of CO2, the volume fraction of CO2 in the flue gas, and the volumetric flow rate of the flue gas;

[0019] (c) The real-time carbon emissions of the coal-fired power units are calculated based on the fitting relationship between the thermal load output and carbon emissions of the coal-fired power units, as detailed below:

[0020] Through polynomial fitting, an empirical formula for the output and carbon emissions of the unit under different heat loads is obtained, and the real-time carbon emissions of the coal-fired power unit are calculated based on this empirical formula.

[0021] The specific formula for step S2 is as follows:

[0022]

[0023]

[0024] in, , and These are the proportions of power generation from coal-fired power units, the proportion of direct external heat supply, and the proportion of power supply for molten salt thermal storage. , and These are the power outputs used for power generation, direct external heat supply, and molten salt thermal storage, respectively, within the total heat supply of coal-fired power units.

[0025] The specific formula for step S3 is as follows:

[0026]

[0027]

[0028] and These are the carbon emission intensity from direct heating by coal-fired power units and the carbon emission intensity from molten salt thermal storage. This is the real-time carbon emissions of the fuel computer group.

[0029] The specific details of step S4 are as follows:

[0030] S41, Obtain the initial heat Q of the molten salt thermal storage system before the thermal storage stage. 熔盐储热，初 and the corresponding initial carbon carrying capacity E 熔盐储热，初 ;

[0031] S42, Obtain the heat storage increment ΔQ of the molten salt thermal energy storage system in the heat storage stage. 熔盐储热 Calculate the heat storage Q of the high-temperature molten salt tank after thermal storage. 熔盐储热，后 ;

[0032] Q 熔盐储热，后 =Q 熔盐储热，初 +ΔQ 熔盐储热

[0033] S43, Obtain the carbon increment ΔE in the thermal storage stage of the molten salt thermal storage system. 熔盐储热Calculate the carbon content E in the high-temperature molten salt tank after thermal storage. 熔盐储热，后 And the carbon carrying capacity per unit heat after thermal storage in molten salt thermal storage system X 储后 ;

[0034] ΔE 熔盐储热 =ΔQ 熔盐储热

[0035] E 熔盐储热，后 =E 熔盐储热，初 +ΔE 熔盐储热

[0036] X 储后 =E 熔盐储热，后 / Q 熔盐储热，后

[0037] S44. If the molten salt thermal storage system does not immediately enter the heat release stage after the thermal storage is completed, obtain the duration of the molten salt thermal storage system in the static stage, consider radiation heat transfer and convection heat transfer, and calculate the natural heat transfer during the static period.

[0038]

[0039] For the heat exchange of molten salt thermal storage systems during the static phase, σ is the surface emissivity; σ is the Stefan-Boltzmann constant; A is the effective area. The temperature of the tank. Natural ambient temperature, For the length of time, The heat transfer coefficient;

[0040] S45, when the system enters the heat release phase, the heat release ΔQ of the molten salt thermal storage system in the external heat release phase is obtained. 熔盐放热 Calculate the heat storage Q of the high-temperature molten salt tank after heat release. 熔盐放热，后 Carbon carrying capacity per unit of heat during the exothermic process (X) 放热 Heat storage capacity E in the high-temperature molten salt tank after heat release 熔盐放热，后 and carbon carrying capacity per unit of heat X 放后 ;

[0041] Q 熔盐放热，后 =Q 熔盐储热，后 —ΔQ 熔盐放热 —ΔQ 自然

[0042] X 放热 =E 熔盐储热，后 / (Q 熔盐储热，后 —ΔQ 自然 )

[0043] E 熔盐放热，后 =E 熔盐储热，后 —ΔQ 熔盐放热X 放热

[0044] X 放后 =E 熔盐放热，后 / Q 熔盐放热，后

[0045] S46, if the subsequent stage continues to release heat, then the carbon carrying capacity per unit heat in this heat release stage is...

[0046] X ‘ 放热 =X 放后

[0047] If heat storage begins in the next stage, then the process will proceed to stage S42.

[0048] The specific details of step S5 are as follows:

[0049] Obtain the external heating parameters of the coal-fired power plant molten salt thermal energy storage system at time t, i.e., steam flow rate. Steam pressure

[0050] P 外 Steam temperature T 外 The formula for calculating the heat flow of steam is:

[0051]

[0052] The heat flow rate of steam. The steam enthalpy at time t is obtained from the steam temperature and steam pressure based on the steam meter and enthalpy-entropy diagram.

[0053] The specific details of step S6 are as follows:

[0054] according to , Determine the heating method: When When the value is 0, the coal-fired power units provide direct heating; when... When the value is 0, the molten salt thermal storage system provides direct heat; when... , When neither value is 0, the coal-fired power unit and the molten salt thermal storage system provide heat together;

[0055] for:

[0056] (a) If the coal-fired power unit provides direct heating, then the carbon emission intensity of the system's heating is:

[0057]

[0058] (b) If the molten salt thermal storage system provides direct heating, then the carbon emission intensity of the system's heating supply is:

[0059]

[0060] (c) If a coal-fired power unit and a molten salt thermal storage system provide heating together, then the carbon emission intensity of the system's heating supply is:

[0061]

[0062] To directly supply heat to coal-fired power units To directly supply heat to the molten salt thermal storage system, for

[0063] Heat exchange efficiency of heaters in heating stations.

[0064] A real-time dynamic heating carbon emission intensity calculation system for a coal-fired power plant molten salt thermal storage system includes:

[0065] Real-time carbon emission calculation module for coal-fired power units: Calculates the real-time carbon emissions of coal-fired power units based on any of the following methods: fuel consumption data, flue gas online monitoring data, or the fitting relationship between the thermal load output and carbon emissions of coal-fired power units.

[0066] Output ratio calculation module: Based on the allocation ratio of the total heat supply of coal-fired power units for power generation, direct external heat supply, and molten salt thermal storage, determine the output ratio of coal-fired power units for direct external heat supply and the output ratio for molten salt thermal storage.

[0067] The carbon emission intensity calculation module for coal-fired power units calculates the carbon emission intensity of direct heating and the carbon emission intensity of molten salt thermal storage by combining the real-time carbon emission amount and the output ratio of each unit.

[0068] The heat release carbon carrying rate calculation module dynamically tracks the carbon carrying capacity of the molten salt thermal storage system. Based on the carbon emission intensity of the molten salt thermal storage process and the increase in heat storage and carbon after thermal storage, it calculates the heat storage and carbon storage after thermal storage, and calculates the carbon carrying rate per unit of heat after thermal storage based on the heat storage and carbon storage. During the heat release phase, it calculates the heat storage after thermal release, the carbon carrying rate per unit of heat after thermal release, and the carbon storage after thermal release based on the heat release, the heat storage after thermal storage, the carbon storage, and the carbon carrying rate per unit of heat after thermal storage, and updates the carbon carrying rate per unit of heat after thermal release.

[0069] Heating flow calculation module: Real-time acquisition of flow rate, pressure and temperature parameters of steam supplied to the external heating system by coal-fired power plant molten salt thermal storage system, and calculation of heating flow at the current moment;

[0070] Heating carbon emission intensity calculation module: Determines the current heating mode, which includes heating by coal-fired power units alone, heating by molten salt thermal storage system alone, and heating by both. Based on the above calculation results, calculates the real-time dynamic heating carbon emission intensity of the coal-fired power molten salt thermal storage system at the current heating mode at that moment.

[0071] A computer device includes a memory and a processor, the memory storing a computer program, characterized in that the processor executes the computer program to implement the steps of the method for calculating the carbon emission intensity of a coal-fired molten salt thermal storage system in real time.

[0072] A computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the method for calculating the carbon emission intensity of a coal-fired molten salt thermal energy storage system in real time.

[0073] The advantages of this invention are: (1) In view of the current situation where there is no clear calculation method for the carbon emission intensity of coal-fired molten salt thermal storage system, this invention abandons the static mode of using fixed factors and periodic statistical values ​​for general estimation, and innovatively constructs a real-time dynamic calculation formula based on the actual operating status of the system. It can dynamically calculate the real carbon emission intensity of the heating link at different times according to the heat storage / release behavior of the molten salt thermal storage system and the operating conditions of the unit, which significantly improves the scientificity and accuracy of the calculation results and provides a reliable methodological basis for accurate carbon tracking and measurement.

[0074] (2) The present invention also takes into account the influence of natural factors. In addition to considering the characteristics of the thermal system itself, it further considers the influence of external environment heat exchange on the system and incorporates this factor into the calculation framework. This makes the final calculated heating carbon emission intensity result not only reflect the carbon emission characteristics of the heat source, but also integrate the natural heat dissipation of the molten salt system itself, ensuring the accuracy and reliability of the evaluation results.

[0075] (3) This method provides a scientific tool for assessing the carbon benefits of flexible retrofitting of coal-fired power plants by accurately quantifying the dynamic changes in carbon emissions brought about by the molten salt thermal storage system in the process of improving heating capacity. Attached Figure Description

[0076] Figure 1 This is a flowchart of the method in an embodiment of the present invention. Detailed Implementation

[0077] A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings.

[0078] like Figure 1 As shown, a method for calculating the carbon emission intensity of a coal-fired molten salt thermal energy storage system in real time includes the following steps:

[0079] S1. Calculate the real-time carbon emissions of the coal-fired power unit based on any of the following methods: fuel consumption data, flue gas online monitoring data, or the fitting relationship between the thermal load output and carbon emissions of the coal-fired power unit.

[0080] S2. Based on the allocation ratio of the total heat supply of coal-fired power units for power generation, direct external heat supply, and molten salt thermal storage, determine the output ratio for direct external heat supply and the output ratio for molten salt thermal storage.

[0081] S3. Combine the real-time carbon emissions obtained from S1 and the output ratios obtained from S2 to calculate the carbon emission intensity of direct heating from coal-fired power units and the carbon emission intensity of molten salt thermal storage.

[0082] S4. Dynamically track carbon carryover in the molten salt thermal storage system. Calculate the heat and carbon storage after storage based on the carbon emission intensity of the molten salt thermal storage stage and the heat and carbon increments after storage. Then, calculate the carbon carryover rate per unit heat after storage based on the heat and carbon storage. Subsequently, considering the duration of the static phase of the molten salt thermal storage system, and taking into account both radiative and convective heat transfer, calculate the natural heat transfer during this static phase. When the system enters the heat release phase, acquire the released heat. Subtract the natural heat transfer and the released heat from the heat stored in the tank after storage to obtain the released heat. After the heat is released, the amount of carbon stored in the tank is divided by the amount of carbon stored after heat storage, after deducting the amount of heat stored after natural heat exchange, to calculate the carbon carrying rate per unit of heat in the heat release stage. Then, the amount of carbon stored in the tank after heat release and the carbon carrying rate per unit of heat in the system are further calculated. Finally, the corresponding process is executed according to the operation type of the next stage of the system. If the next stage continues to release heat, the carbon carrying rate per unit of heat after this heat release is used as the carbon carrying rate per unit of heat in the next stage of heat release. If the next stage starts to store heat, the calculation of the heat storage increment is returned to the calculation stage, and the calculation of the heat storage-related parameters is carried out again.

[0083] S5. Real-time acquisition of the flow rate, pressure, and temperature parameters of the external heating steam of the coal-fired power plant molten salt thermal storage system, and calculation of the current heating flow rate;

[0084] S6. Determine the current heating mode, which includes heating by coal-fired power units alone, heating by molten salt thermal storage system alone, and heating by both. Calculate the real-time dynamic heating carbon emission intensity of the coal-fired power molten salt thermal storage system at this moment under the current heating mode based on the calculation results of steps S3, S4, and S5.

[0085] The specific details of step S1 are as follows:

[0086] (a) The calculation of real-time carbon emissions from coal-fired power units based on fuel consumption data is as follows:

[0087] The real-time carbon emissions of coal-fired power units are calculated based on the carbon oxidation rate of fuel carbon, the carbon content of the received basic elements, and the unit's fuel consumption. The carbon oxidation rate of fuel carbon is calculated using the average carbon content of ash and slag. This average carbon content is derived from the mass fraction of slag in the total fuel ash, the mass fraction of fly ash in the total fuel ash, the mass fraction of combustibles in the slag, and the mass fraction of combustibles in the fly ash, as shown in the following formula:

[0088]

[0089] In the formula:

[0090] — This represents the carbon oxidation rate of fuel carbon, expressed as a percentage, and is the average value calculated from the unit's statistics.

[0091] —The carbon content of the fuel, expressed as a percentage (%).

[0092] —This represents the unit's fuel consumption, expressed in tons (t).

[0093] The carbon oxidation rate is calculated using the following formula:

[0094]

[0095] In the formula:

[0096] —Average carbon content of ash and slag, which is the percentage of average carbon content in ash and slag relative to the total amount of coal ash, expressed in % %.

[0097] Ash content of fuel carbon as received, in %

[0098] The average carbon content of ash is calculated using the following formula:

[0099]

[0100] In the formula:

[0101] —The mass fraction of slag in the total fuel ash, expressed as a percentage;

[0102] —The mass fraction of fly ash in the total fuel ash, expressed as %

[0103] —The mass fraction of combustibles in the slag, in units of %.

[0104] —This represents the mass fraction of combustibles in fly ash, expressed in units of %.

[0105] (b) Calculate the real-time carbon emissions of the coal-fired power unit based on the online flue gas monitoring data, as follows:

[0106] The calculation is based on the density of CO2, the volume fraction of CO2 in the flue gas, and the volumetric flow rate of the flue gas. The calculation formula is as follows:

[0107]

[0108] In the formula:

[0109] —This refers to the density of CO2;

[0110] —This represents the volume fraction of CO2 in the flue gas;

[0111] —This represents the volumetric flow rate of the flue gas, in cubic meters per second (m³). 3 / h;

[0112] (c) The real-time carbon emissions of the coal-fired power units are calculated based on the fitting relationship between the thermal load output and carbon emissions of the coal-fired power units, as detailed below:

[0113] Through polynomial fitting, an empirical formula for the relationship between unit output and carbon emissions under different heat loads is obtained. Based on this empirical formula, the real-time carbon emissions of the coal-fired power unit are then calculated. The calculation formula is as follows:

[0114]

[0115] To supply power to the unit's thermal load; , , d and d are characteristic coefficients related to the generator set;

[0116] The specific formula for step S2 is as follows:

[0117]

[0118]

[0119]

[0120] in, , and These are the proportions of power generation from coal-fired power units, the proportion of direct external heat supply, and the proportion of power supply for molten salt thermal storage. , and These are the power outputs used for power generation, direct external heat supply, and molten salt thermal storage, respectively, within the total heat supply of coal-fired power units.

[0121] The specific formula for step S3 is as follows:

[0122]

[0123]

[0124] and These are the carbon emission intensity from direct heating by coal-fired power units and the carbon emission intensity from molten salt thermal storage.

[0125] The specific details of step S4 are as follows:

[0126] S41, Obtain the initial heat Q of the molten salt thermal storage system before the thermal storage stage. 熔盐储热，初 and the corresponding initial carbon carrying capacity E 熔盐储热，初 ;

[0127] S42, Obtain the heat storage increment ΔQ of the molten salt thermal energy storage system in the heat storage stage. 熔盐储热 Calculate the heat storage Q of the high-temperature molten salt tank after thermal storage. 熔盐储热，后 ;

[0128] Q 熔盐储热，后 =Q 熔盐储热，初 +ΔQ 熔盐储热

[0129] S43, Obtain the carbon increment ΔE in the thermal storage stage of the molten salt thermal storage system. 熔盐储热 Calculate the carbon content E in the high-temperature molten salt tank after thermal storage. 熔盐储热，后 And the carbon carrying capacity per unit heat after thermal storage in molten salt thermal storage system X 储后 ;

[0130] ΔE 熔盐储热 =ΔQ 熔盐储热

[0131] E 熔盐储热，后 =E 熔盐储热，初 +ΔE 熔盐储热

[0132] X 储后 =E 熔盐储热，后 / Q 熔盐储热，后

[0133] S44. If the molten salt thermal storage system does not immediately enter the heat release stage after the thermal storage is completed, obtain the duration of the molten salt thermal storage system in the static stage, consider radiation heat transfer and convection heat transfer, and calculate the natural heat transfer during the static period.

[0134]

[0135] For the heat exchange of molten salt thermal storage systems during the static phase, σ is the surface emissivity; σ is the Stefan-Boltzmann constant; A is the effective area. The temperature of the tank. Natural ambient temperature, For the length of time, The heat transfer coefficient;

[0136] S45, when the system enters the heat release phase, the heat release ΔQ of the molten salt thermal storage system in the external heat release phase is obtained. 熔盐放热 Calculate the heat storage Q of the high-temperature molten salt tank after heat release. 熔盐放热，后 Carbon carrying capacity per unit of heat during the exothermic process (X) 放热 Heat storage capacity E in the high-temperature molten salt tank after heat release 熔盐放热，后 and carbon carrying capacity per unit of heat X 放后 ;

[0137] Q 熔盐放热，后 =Q 熔盐储热，后 —ΔQ 熔盐放热 —ΔQ 自然

[0138] X 放热 =E 熔盐储热，后 / (Q 熔盐储热，后 —ΔQ 自然 )

[0139] E 熔盐放热，后 =E 熔盐储热，后 —ΔQ 熔盐放热 X 放热

[0140] X 放后 =E 熔盐放热，后 / Q 熔盐放热，后

[0141] S46, if the subsequent stage continues to release heat, then the carbon carrying capacity per unit heat in this heat release stage is...

[0142] X ‘ 放热 =X 放后

[0143] If heat storage begins in the next stage, then the process will proceed to stage S42.

[0144] The specific details of step S5 are as follows:

[0145] Obtain the external heating parameters of the coal-fired power plant molten salt thermal energy storage system at time t, i.e., steam flow rate. Steam pressure

[0146] P 外 Steam temperature T 外 The formula for calculating the heat flow of steam is:

[0147]

[0148] The heat flow rate of steam. The steam enthalpy at time t is obtained from the steam temperature and steam pressure based on the steam meter and enthalpy-entropy diagram.

[0149] The specific details of step S6 are as follows:

[0150] according to , Determine the heating method: When When the value is 0, the coal-fired power units provide direct heating; when... When the value is 0, the molten salt thermal storage system provides direct heat; when... , When neither value is 0, the coal-fired power unit and the molten salt thermal storage system provide heat together; and The calculation formula is similar The calculation formula is existing technology.

[0151] for:

[0152] (a) If the coal-fired power unit provides direct heating, then the carbon emission intensity of the system's heating is:

[0153]

[0154] (b) If the molten salt thermal storage system provides direct heating, then the carbon emission intensity of the system's heating supply is:

[0155]

[0156] (c) If a coal-fired power unit and a molten salt thermal storage system provide heating together, then the carbon emission intensity of the system's heating supply is:

[0157]

[0158] To directly supply heat to coal-fired power units To directly supply heat to the molten salt thermal storage system, The heat exchange efficiency of the heater in the heating station.

[0159] Example 1:

[0160] (1) Carbon emission data of a 660MW unit under different heat load output conditions.

[0161]

[0162] By fitting polynomials, empirical formulas for output and carbon emissions under different heat loads are obtained.

[0163]

[0164] (2) Calculation of the proportion of different outputs of the unit:

[0165] The unit's heat load output at a certain time is 4200 GJ / h. According to the above formula, the carbon emission is 421.61 t / h.

[0166]

[0167]

[0168]

[0169]

[0170] (3) Calculation of carbon emission intensity for molten salt supply and direct heating of the unit:

[0171]

[0172]

[0173] Calculations show that at this time It is 0.1004 t / GJ; It is 0.1004 t / GJ.

[0174] (4) Calculation of carbon emissions from molten salt heating:

[0175] S41, Obtain the initial heat Q of the molten salt system before the heat storage stage. 熔盐储热，初 The value is 600 GJ, corresponding to an initial carbon carrying capacity E. 熔盐储热，初 The value is 60t (this is initially assumed to be 0.1t / GJ, and will be iterated over time as heat storage and heat release are carried out).

[0176] S42, Obtain the heat storage increment ΔQ of the molten salt system in the heat storage stage. 熔盐储热 The value is 300 GJ, and the heat storage capacity Q of the high-temperature molten salt tank after thermal storage is calculated. 熔盐储热，后 It is 900 GJ;

[0177] Q 熔盐储热，后 =Q 熔盐储热，初 +ΔQ 熔盐储热

[0178] S43, Obtain the carbon increment ΔE of the molten salt system during the thermal storage stage. 熔盐储热 The value is 30.12t, and the carbon content E in the high-temperature molten salt tank after thermal storage is calculated. 熔盐储热，后 The carbon carrying capacity per unit heat of the molten salt thermal storage system is 90.12t. 储后 It is 0.10013 t / GJ;

[0179] ΔE 熔盐储热 =ΔQ 熔盐储热

[0180] E 熔盐储热，后 =E 熔盐储热，初 +ΔE 熔盐储热

[0181] X 储后 =E 熔盐储热，后 / Q熔盐储热，后

[0182] S44, if the molten salt system is in the settling phase for a certain period of time Calculate the natural heat exchange during the resting period (considering radiation and convection heat exchange).

[0183] It is estimated that the static heat loss of the system is 0.05 GJ / h when the ambient temperature is 20℃.

[0184]

[0185] After standing for 10 hours, the system's natural heat loss ΔQ 自然 It is 0.5 GJ.

[0186] S45, Obtain the heat release ΔQ of the molten salt system for the external heat release process. 熔盐放热 The heat transfer efficiency is 400 GJ, and the carbon carrying capacity per unit heat during the exothermic process is X. 放热 It is 0.10019 t / GJ.

[0187] X 放热 =E 熔盐储热，后 / (Q 熔盐储热，后 —ΔQ 自然 )

[0188] Calculate the heat storage Q of the high-temperature molten salt tank after heat release. 熔盐放热，后 The carbon content E of the high-temperature molten salt tank after exothermic reaction is 499.5 GJ. 熔盐储热，后 The value is 50.044t and the carbon carrying capacity per unit heat is X. 放后 It is 0.10019 t / GJ;

[0189] Q 熔盐放热，后 =Q 熔盐储热，后 —ΔQ 熔盐放热 —ΔQ 自然

[0190] E 熔盐放热，后 =E 熔盐储热，后 —ΔQ 熔盐放热 X 放热

[0191] X 放后 =E 熔盐放热，后 / Q 熔盐放热，后

[0192] S46, the next stage continues to release heat, then the carbon carrying rate of the unit heat in the molten salt system at this time is 0.10019t / GJ.

[0193] X ‘ 放热 =X 放后

[0194] (5) Calculation of the proportion of different unit outputs at the moment of molten salt heat release.

[0195] The unit's heat load output at a certain time is 2000 GJ / h. According to the above formula, the carbon emission is 201.57 t / h.

[0196]

[0197] (6) Calculation of carbon emission intensity of direct heating unit It is 0.10079 t / GJ.

[0198] (7) The heating method is determined to be (c) the unit and the molten salt thermal storage system provide heating together, and the heat exchanger efficiency is 99%.

[0199]

[0200]

[0201] In summary, when computer groups and molten salt thermal storage systems are used for combined heating... It is 0.10161t / GJ.

[0202] This invention provides a computer device, which may be a server. The device includes a processor, a memory, and a network interface connected via a system bus. The processor provides computing and control capabilities; the memory includes a non-volatile storage medium and internal memory, wherein the non-volatile storage medium stores an operating system, computer programs, and a database, and the internal memory provides an environment for the operation of the operating system and computer programs; the database stores data related to the methods described above; and the network interface enables network communication with external terminals. When the computer program is executed by the processor, the methods described above can be implemented.

[0203] This invention provides a computer-readable storage medium, which may be ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage device, quantum memory, or any combination of the above media. The computer-readable storage medium stores a set of computer program instructions. When executed by a processor, the instruction set can fully implement all the steps of the method described in this invention and achieve the same technical effect. The storage medium may be sold and distributed independently or integrated with hardware devices, all of which fall within the scope of protection of this invention.

[0204] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention, and no reference numerals in the claims should be construed as limiting the scope of the claims.

[0205] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for calculating the carbon emission intensity of a coal-fired molten salt thermal energy storage system under real-time dynamic heating, characterized in that: Specifically, the steps include the following: S1. Calculate the real-time carbon emissions of the coal-fired power unit based on any of the following methods: fuel consumption data, flue gas online monitoring data, or the fitting relationship between the thermal load output and carbon emissions of the coal-fired power unit. S2. Based on the allocation ratio of the total heat supply of coal-fired power units for power generation, direct external heat supply, and molten salt thermal storage, determine the proportion of the output of coal-fired power units for direct external heat supply and the proportion of the output for molten salt thermal storage. S3. Combine the real-time carbon emissions obtained from S1 and the output ratios obtained from S2 to calculate the carbon emission intensity of direct heating from coal-fired power units and the carbon emission intensity of molten salt thermal storage. S4. Perform dynamic carbon carrying tracking on the molten salt thermal storage system. Based on the carbon emission intensity of the molten salt thermal storage stage and the increase in thermal storage and carbon after thermal storage, calculate the heat and carbon content after thermal storage, and calculate the carbon carrying rate per unit heat after thermal storage based on the heat and carbon content. Combine the duration of the static stage of the molten salt thermal storage system to calculate the natural heat exchange during the static stage. When entering the heat release stage, acquire the heat released to the outside, subtract the natural heat exchange and the heat released to the outside from the heat stored in the tank after thermal storage to obtain the heat stored in the tank after heat release. Then divide the carbon content after thermal storage by the heat stored after deducting the natural heat exchange to calculate the carbon carrying rate per unit heat in the heat release stage, and further calculate the carbon content in the tank after heat release and the carbon carrying rate per unit heat in the system. If the next stage continues to release heat, use the carbon carrying rate per unit heat after this heat release as the carbon carrying rate per unit heat in the next stage of heat release. If the next stage starts thermal storage, return to the calculation stage of thermal storage increment and recalculate. S5. Real-time acquisition of the flow rate, pressure, and temperature parameters of the external heating steam of the coal-fired power plant molten salt thermal storage system, and calculation of the current heating flow rate; S6. Determine the current heating mode, which includes heating by coal-fired power units alone, heating by molten salt thermal storage system alone, and heating by both. Calculate the real-time dynamic heating carbon emission intensity of the coal-fired power molten salt thermal storage system at this moment under the current heating mode based on the calculation results of steps S3, S4, and S5.

2. The method for calculating the carbon emission intensity of a coal-fired molten salt thermal energy storage system under real-time dynamic heating according to claim 1, characterized in that: The specific details of step S1 are as follows: (a) The calculation of real-time carbon emissions from coal-fired power units based on fuel consumption data is as follows: The real-time carbon emissions of coal-fired power units are calculated based on the carbon oxidation rate of fuel carbon, the carbon content of the basic elements, and the fuel consumption of the unit. The carbon oxidation rate of fuel carbon is obtained by calculating the average carbon content of ash and slag, which is calculated based on the mass fraction of slag in the total ash of fuel, the mass fraction of fly ash in the total ash of fuel, the mass fraction of combustibles in slag, and the mass fraction of combustibles in fly ash. (b) Calculate the real-time carbon emissions of the coal-fired power unit based on the online flue gas monitoring data, as follows: It is calculated based on the density of CO2, the volume fraction of CO2 in the flue gas, and the volumetric flow rate of the flue gas; (c) The real-time carbon emissions of the coal-fired power units are calculated based on the fitting relationship between the thermal load output and carbon emissions of the coal-fired power units, as detailed below: Through polynomial fitting, an empirical formula for the output and carbon emissions of the unit under different heat loads is obtained, and the real-time carbon emissions of the coal-fired power unit are calculated based on this empirical formula.

3. The method for calculating the carbon emission intensity of a coal-fired molten salt thermal energy storage system under real-time dynamic heating according to claim 1, characterized in that: The specific formula for step S2 is as follows: in, and These are the proportions of power generation from coal-fired power units, the proportion of direct external heat supply, and the proportion of power supply for molten salt thermal storage. , and These are the power outputs used for power generation, direct external heat supply, and molten salt thermal storage, respectively, within the total heat supply of coal-fired power units.

4. The method for calculating the carbon emission intensity of a coal-fired molten salt thermal energy storage system under real-time dynamic heating according to claim 3, characterized in that: The specific formula for step S3 is as follows: and These are the carbon emission intensity from direct heating by coal-fired power units and the carbon emission intensity from molten salt thermal storage. This is the real-time carbon emissions of the fuel computer group.

5. The method for calculating the carbon emission intensity of a coal-fired molten salt thermal energy storage system under real-time dynamic heating according to claim 4, characterized in that: The specific details of step S4 are as follows: S41, Obtain the initial heat Q of the molten salt thermal storage system before the thermal storage stage. 熔盐储热，初 and the corresponding initial carbon carrying capacity E 熔盐储热，初 ; S42, Obtain the heat storage increment ΔQ of the molten salt thermal energy storage system in the heat storage stage. 熔盐储热 Calculate the heat storage Q of the high-temperature molten salt tank after thermal storage. 熔盐储热，后 ; Q 熔盐储热，后 =Q 熔盐储热，初 +ΔQ 熔盐储热 S43, Obtain the carbon increment ΔE in the thermal storage stage of the molten salt thermal storage system. 熔盐储热 Calculate the carbon content E in the high-temperature molten salt tank after thermal storage. 熔盐储热，后 And the carbon carrying capacity per unit heat after thermal storage in molten salt thermal storage system X 储后 ; ΔE 熔盐储热 =ΔQ 熔盐储热 E 熔盐储热，后 =E 熔盐储热，初 +ΔE 熔盐储热 X 储后 =E 熔盐储热，后 / Q 熔盐储热，后 S44. If the molten salt thermal storage system does not immediately enter the heat release stage after the thermal storage is completed, obtain the duration of the molten salt thermal storage system in the static stage, consider radiation heat transfer and convection heat transfer, and calculate the natural heat transfer during the static period. For the heat exchange during the static phase of the molten salt thermal storage system, σ is the surface emissivity; σ is the Stefan-Boltzmann constant; A is the effective area. The temperature of the tank. Natural ambient temperature, For the length of time, The heat transfer coefficient; S45, when the system enters the heat release phase, the heat release ΔQ of the molten salt thermal storage system in the external heat release phase is obtained. 熔盐放热 Calculate the heat storage Q of the high-temperature molten salt tank after heat release. 熔盐放热，后 Carbon carrying capacity per unit heat during the exothermic process (X) 放热 Heat storage capacity E in the high-temperature molten salt tank after heat release 熔盐放热，后 and carbon carrying capacity per unit of heat X 放后 ; Q 熔盐放热，后 =Q 熔盐储热，后 —ΔQ 熔盐放热 —ΔQ 自然 X 放热 =E 熔盐储热，后 / (Q 熔盐储热，后 —ΔQ 自然 ) It is 熔盐放热，后 =E 熔盐储热，后 —ΔQ 熔盐放热 X 放热 X 放后 =E 熔盐放热，后 / Q 熔盐放热，后 S46, if the subsequent stage continues to release heat, then the carbon carrying capacity per unit heat in this heat release stage is... X ‘ 放热 =X 放后 If heat storage begins in the next stage, then the process will proceed to stage S42.

6. The method for calculating the carbon emission intensity of a coal-fired molten salt thermal energy storage system under real-time dynamic heating according to claim 5, characterized in that: The specific details of step S5 are as follows: Obtain the external heating parameters of the coal-fired power plant molten salt thermal energy storage system at time t, i.e., steam flow rate. Steam pressure P 外 Steam temperature T 外 The formula for calculating the heat flow of steam is: The heat flow rate of steam. The steam enthalpy at time t is obtained from the steam temperature and steam pressure based on the steam meter and enthalpy-entropy diagram.

7. The method for calculating the carbon emission intensity of a coal-fired molten salt thermal energy storage system under real-time dynamic heating according to claim 6, characterized in that: The specific details of step S6 are as follows: According to the direct heat supply of coal-fired power units Molten salt thermal storage system directly supplies heat Determine the heating method: When When the value is 0, the coal-fired power units provide direct heating; when... When the value is 0, the molten salt thermal storage system provides direct heating; when... , When neither value is 0, the coal-fired power unit and the molten salt thermal storage system provide heat together; for: (a) If the coal-fired power unit provides direct heating, then the carbon emission intensity of the system's heating is: (b) If the molten salt thermal storage system provides direct heating, then the carbon emission intensity of the system's heating supply is: (c) If a coal-fired power unit and a molten salt thermal storage system provide heating together, then the carbon emission intensity of the system's heating supply is: The heat exchange efficiency of the heater in the heating station.

8. A real-time dynamic heating carbon emission intensity calculation system for a coal-fired molten salt thermal energy storage system, characterized in that: Including: Real-time carbon emission calculation module for coal-fired power units: Calculates the real-time carbon emissions of coal-fired power units based on any of the following methods: fuel consumption data, flue gas online monitoring data, or the fitting relationship between the thermal load output and carbon emissions of coal-fired power units. Output ratio calculation module: Based on the allocation ratio of the total heat supply of coal-fired power units for power generation, direct external heat supply, and molten salt thermal storage, determine the output ratio of coal-fired power units for direct external heat supply and the output ratio for molten salt thermal storage. The carbon emission intensity calculation module for coal-fired power units calculates the carbon emission intensity of direct heating and the carbon emission intensity of molten salt thermal storage by combining the real-time carbon emission amount and the output ratio of each unit. The heat release carbon carrying rate calculation module dynamically tracks the carbon carrying capacity of the molten salt thermal storage system. Based on the carbon emission intensity of the molten salt thermal storage process and the increase in heat storage and carbon after thermal storage, it calculates the heat storage and carbon storage after thermal storage, and calculates the carbon carrying rate per unit of heat after thermal storage based on the heat storage and carbon storage. During the heat release phase, it calculates the heat storage after thermal release, the carbon carrying rate per unit of heat after thermal release, and the carbon storage after thermal release based on the heat release, the heat storage after thermal storage, the carbon storage, and the carbon carrying rate per unit of heat after thermal storage, and updates the carbon carrying rate per unit of heat after thermal release. Heating flow calculation module: Real-time acquisition of flow rate, pressure and temperature parameters of steam supplied to the external heating system by coal-fired power plant molten salt thermal storage system, and calculation of heating flow at the current moment; Heating carbon emission intensity calculation module: Determines the current heating mode, which includes heating by coal-fired power units alone, heating by molten salt thermal storage system alone, and heating by both. Based on the above calculation results, calculates the real-time dynamic heating carbon emission intensity of the coal-fired power molten salt thermal storage system at the current heating mode at that moment.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method for calculating the carbon emission intensity of a coal-fired molten salt thermal storage system according to any one of claims 1-7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the method for calculating the carbon emission intensity of the real-time dynamic heating system of the coal-fired molten salt thermal storage system as described in any one of claims 1-7.

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