Thermodynamic calculation method for combustion boiler in low-pressure environment

Abstract

The invention discloses a thermodynamic calculation method for a combustion boiler in a low-pressure environment, and relates to the technical field of boilers. The method comprises the following steps: determining an absorption coefficient of each participating gas in a combustion boiler in a low-pressure environment according to a function relationship between a spectral parameter of the gas and the absorption coefficient, then determining an absorption coefficient of a mixed gas in the combustion boiler according to the absorption coefficient of each participating gas, and determining the absorption coefficient of the mixed gas in the combustion boiler according to the absorption coefficient of the mixed gas, the stroke length and the absolute temperature. And obtaining the triatomic gas emissivity from a pre-constructed triatomic gas emissivity database so as to determine the flame blackness of the combustion boiler according to the triatomic gas emissivity. According to the method, the flame blackness of the combustion boiler in the low-pressure environment can be calculated.

Description

Technical Field

[0001] The invention relates to the technical field of boilers, and in particular to a thermal calculation method for a combustion boiler in a low-pressure environment. Background Art

[0002] At present, the unique geographical characteristics of the high-altitude areas in western China have created the characteristics of low air pressure, which poses a severe challenge to the performance of combustion equipment. Accurate thermal calculation of boilers is of great significance to the production and operation of equipment.

[0003] Among them, flame blackness is an important parameter to measure the flame radiation capacity, and it plays a key role in boiler heat transfer calculations. With the advancement of calculation methods and tools, the boiler's combustion process can be more accurately predicted and controlled by the boiler's flame blackness, thereby improving the boiler's efficiency and safety. At present, the flame blackness during boiler combustion is determined by thermal calculations. However, there are significant differences in the radiation characteristics of triatomic gases between boiler combustion in a low-pressure environment and boiler combustion in a normal-pressure environment. The delay in ignition in the furnace caused by the reduction in air pressure changes the flame morphology and temperature distribution, making the existing thermal calculations unsuitable for thermal calculations of combustion boilers in a low-pressure environment.

[0004] Therefore, there is an urgent need for a thermal calculation method that can be used for combustion boilers in low-pressure environments. Summary of the invention

[0005] Based on this, it is necessary to provide a thermal calculation method for a combustion boiler in a low-pressure environment to address the above technical problems. The method can calculate the flame blackness of a combustion boiler in a low-pressure environment.

[0006] The present invention adopts the following technical solutions: The present invention provides a thermal calculation method for a combustion boiler in a low pressure environment, comprising: According to the functional relationship between the spectral parameters and the absorption coefficient of the gas, the absorption coefficient of each participating gas in the combustion boiler under low pressure environment is determined; According to the absorption coefficient of each participating gas, the absorption coefficient of the mixed gas in the combustion boiler is determined; Determine the triatomic gas emissivity from a pre-constructed triatomic gas emissivity database according to the absorption coefficient, the path length and the absolute temperature of the mixed gas; the path length is the effective radiation layer thickness of the combustion boiler; The flame blackness of combustion boilers is determined by the emissivity of triatomic gases.

[0007] Preferably, the absorption coefficient of each participating gas in the combustion boiler under a low pressure environment is determined according to the functional relationship between the spectral parameter of the gas and the absorption coefficient, including: Obtain the absorption spectrum of each gas involved in boiler combustion; The spectral parameters of each absorption spectrum are respectively substituted into the functional relationship between the spectral parameters of the gas and the absorption coefficient to obtain the absorption coefficient of each participating gas.

[0008] Preferably, the spectral parameters include partial pressure of the gas, degeneracy factor, degeneracy, spectral line center wave number, pressure broadening half width, Doppler broadening half width, air broadening half width and self-broadening half width; the functional relationship between the spectral parameters and the absorption coefficient includes: ; ; ; ; ; ; ; in, For the i The absorption coefficient of the absorption spectrum, is the molecular number density of the gas, For the The intensity of the absorption spectrum line, For the The linear function of the spectral line, is Avogadro's constant, is the gas constant, is the partial pressure of the gas, is the absolute temperature of the gas; is the reference temperature, is Planck's constant, is the lower energy level representing the transition, is the vibrational partition function, is the rotation allocation function, is the speed of light in vacuum, is the Boltzmann constant, is the degeneracy factor; is the degree of simplicity, is the rotation energy level, is the vibration energy level, is the spectral line wave number, is the central wave number of the spectral line, The half width is increased by pressure. is the Doppler half-width, Add half the width of the air, is the self-augmented half-width, is the partial pressure of the participating gases, is the temperature dependence of the half-width of the air widening.

[0009] Preferably, the process of constructing the functional relationship between the spectral parameter and the absorption coefficient includes: Based on the line-by-line method and high-resolution spectral database, the functional relationship between the spectral parameters of the gas and the absorption coefficient is established.

[0010] Preferably, the triatomic gas emissivity database includes a total emissivity expression; determining the triatomic gas emissivity from a pre-constructed triatomic gas emissivity database according to the absorption coefficient, the path length and the absolute temperature of the mixed gas comprises: Substituting the absorption coefficient, path length and absolute temperature of the mixed gas into the total emissivity expression, the triatomic gas emissivity is obtained.

[0011] Preferably, the process of constructing the total emissivity expression includes: Obtaining sample spectral parameters from a spectral database, and determining the absorption coefficient of the sample mixed gas through a functional relationship between the spectral parameters of the gas and the absorption coefficient; According to the absorption coefficient, path length and absolute temperature of the sample mixed gas, the total emissivity expression is constructed; the total emissivity expression is: ; ; in, is the triatomic gas emissivity, is the blackbody spectral radiation intensity, is the absorption coefficient of the sample gas mixture, is the Stefan-Boltzmann constant, is the first radiation constant of Planck's law, is the second radiation constant of Planck's law, L is the stroke length.

[0012] Preferably, the absorption coefficient of the mixed gas in the combustion boiler is determined according to the absorption coefficient of each participating gas, including: The absorption coefficient of each participating gas is added together to determine the absorption coefficient of the mixed gas.

[0013] The present invention provides a thermal calculation device for a combustion boiler in a low-pressure environment, comprising: The first determination module is used to determine the absorption coefficient of each participating gas in the combustion boiler under a low pressure environment according to the functional relationship between the spectral parameter of the gas and the absorption coefficient; A second determination module is used to determine the absorption coefficient of the mixed gas in the combustion boiler according to the absorption coefficient of each participating gas; The third determination module is used to determine the triatomic gas emissivity from a pre-constructed triatomic gas emissivity database according to the absorption coefficient, the stroke length and the absolute temperature of the mixed gas; the stroke length is the effective radiation layer thickness of the combustion boiler; The fourth determination module is used to determine the flame blackness of the combustion boiler through the triatomic gas emissivity.

[0014] The present invention provides a computer-readable storage medium, wherein the storage medium stores a computer program, and when the computer program is executed by a processor, the thermal calculation method for a combustion boiler under a low-pressure environment is implemented.

[0015] The present invention provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the thermal calculation method for a combustion boiler under a low-pressure environment is implemented.

[0016] At least one of the above technical solutions adopted by the present invention can achieve the following beneficial effects: In the present invention, the absorption coefficient of each participating gas in the combustion boiler under a low-pressure environment is determined based on the pre-constructed functional relationship between the spectral parameters and the absorption coefficient of the gas, and then the absorption coefficient of the mixed gas in the combustion boiler is determined through the absorption coefficient of each participating gas. According to the absorption coefficient, stroke length and absolute temperature of the mixed gas, the triatomic gas emissivity is obtained from a pre-constructed triatomic gas emissivity database to determine the flame blackness of the combustion boiler based on the triatomic gas emissivity, thereby realizing the thermal calculation of boiler combustion under a low-pressure environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings: Figure 1 A schematic flow chart of a method for calculating the thermal power of a combustion boiler in a low-pressure environment provided by the present invention; Figure 2 A schematic diagram of calculation results of the radiation attenuation coefficient of a triatomic gas obtained under different stroke lengths, temperatures, pressures and a mole fraction of 1 provided by the present invention; Figure 3 A schematic diagram of calculation results of the radiation attenuation coefficient of a triatomic gas obtained under different stroke lengths, temperatures, pressures and a mole fraction of 2 provided by the present invention; Figure 4 A schematic diagram of a thermal calculation device for a combustion boiler in a low-pressure environment provided by the present invention; Figure 5 A schematic diagram of a computer device for realizing a thermal calculation method for a combustion boiler in a low-pressure environment provided by the present invention. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] The unique geographical characteristics of the high-altitude areas in western China have created its low air pressure characteristics, which poses a severe challenge to the performance of combustion equipment. Accurate thermal calculation of boilers is of great significance to the production and operation of equipment. However, there are significant differences in the radiation characteristics of triatomic gases between low-pressure air combustion atmosphere and normal-pressure air combustion atmosphere. This difference not only affects the radiation heat transfer characteristics in the furnace, but also changes the convection heat transfer characteristics of the convection heating surface. At the same time, the delay in ignition in the furnace caused by the reduction in air pressure changes the shape and temperature distribution of the flame, and also has a certain impact on the calculation of radiation and furnace outlet flue gas temperature, which makes the applicability and accuracy of existing thermal calculations questionable and no longer applicable to low-pressure boilers.

[0020] Therefore, in order to more accurately perform thermal calculations of boilers under low-pressure conditions, the present invention proposes a thermal calculation method for combustion boilers under low-pressure conditions. This method is suitable for the thermal calculation method of low-pressure combustion boilers and can provide guidance for the design and operation of low-pressure combustion boilers or the transformation of normal-pressure combustion boilers to low-pressure combustion boilers.

[0021] The technical solutions provided by various embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

[0022] Figure 1 This is a flow chart of a method for calculating the thermal power of a combustion boiler under a low pressure environment in the present invention, which specifically includes the following steps: S101, determining the absorption coefficient of each participating gas in a combustion boiler under a low pressure environment according to a functional relationship between a spectral parameter of the gas and the absorption coefficient.

[0023] Among them, the functional relationship between the spectral parameters of the gas and the absorption coefficient can be established based on the line-by-line method and the high-resolution spectral database; the spectral parameters include the partial pressure of the gas, the degeneracy factor, the degeneracy, the center wave number of the spectral line, the pressure broadening half-width, the Doppler broadening half-width, the air broadening half-width and the self-broadening half-width; the functional relationship between the spectral parameters and the absorption coefficient includes: (1); (2); (3); (4); (5); (6); (7); in, For the i Absorption coefficient of the absorption spectrum; is the molecular number density of the gas, which can be determined using the ideal gas state equation; For the i The intensity of the absorption spectrum line, in cm⁻²; For the i Linear functions of spectral lines, including Lorentz profile, Doppler profile and Vogit profile; is Avogadro's constant, which can be 6.022×10²³ mol⁻¹; is the gas constant, which can be 8.314 J·K⁻¹·mol⁻¹; is the partial pressure of the gas, in bar; is the absolute temperature of the gas, in K; is the reference temperature, 296K; is Planck's constant, which can be 6.62607015×10 -34 J.s; is the lower energy level representing the transition, in cm -1 ; is the vibrational partition function, is the rotation allocation function, is the speed of light in a vacuum, which can be taken as 2.99792458×10 8 m·s -1 ; is the Boltzmann constant, which can be 1.380649×10 -23 J.K. -1 ; is the degeneracy factor; is the degree of simplicity, is the rotational energy level, in cm -1 ; is the vibration energy level, in cm -1 ; is the spectral line wave number, is the central wave number of the spectral line, in cm -1 ; The half width is increased by pressure. is the Doppler broadening half width, in cm -1 ·atm -1 ; The half width of air, in cm -1 ·atm -1 ; The half width of the self-increase, in cm -1 ·atm -1 ; is the partial pressure of the participating gases, in bar; is the temperature dependence coefficient of the half-width of air broadening, dimensionless.

[0024] Therefore, according to the functional relationship between the spectral parameters and the absorption coefficient of the gas, the absorption coefficient of each participating gas in the combustion boiler under a low-pressure environment is determined, including: obtaining the absorption spectrum of each participating gas during boiler combustion; substituting the spectral parameters of each absorption spectrum into the functional relationship between the spectral parameters and the absorption coefficient of the gas, and obtaining the absorption coefficient of each participating gas.

[0025] Specifically, each participating gas has specific spectral parameters. Therefore, a high-resolution spectrometer can be used to measure the absorption spectrum generated when the boiler is burned. Each absorption spectrum corresponds to a participating gas. The spectral parameters of each absorption spectrum are then substituted into the functional relationship between the spectral parameters of the gas and the absorption coefficient to obtain the absorption coefficient of each participating gas.

[0026] S102, determining the absorption coefficient of the mixed gas in the combustion boiler according to the absorption coefficient of each participating gas.

[0027] The absorption coefficient of the mixed gas in the combustion boiler is determined according to the absorption coefficient of each participating gas, including: adding the absorption coefficients of each participating gas to determine the absorption coefficient of the mixed gas.

[0028] For example, taking the participating gases including carbon dioxide (CO2) and water (H2O) as an example, as shown in formula (8), the calculation formula of the mixed gas absorption coefficient can be expressed as: (8); in, is the absorption coefficient of the mixed gas, is the absorption coefficient of CO2; is the absorption coefficient of H2O.

[0029] S103, determining the triatomic gas emissivity from a pre-constructed triatomic gas emissivity database according to the absorption coefficient, the path length and the absolute temperature of the mixed gas.

[0030] The stroke length is the thickness of the effective radiation layer of the combustion boiler.

[0031] Preferably, the triatomic gas emissivity database includes a total emissivity expression; the construction process of the total emissivity expression may be: obtaining sample spectral parameters from the spectral database, and determining the absorption coefficient of the sample mixed gas through the functional relationship between the spectral parameters of the gas and the absorption coefficient.

[0032] According to the absorption coefficient, path length and absolute temperature of the sample mixed gas, the total emissivity expression is constructed. The total emissivity expression can be expressed as: (9); (10); in, is the triatomic gas emissivity, is the blackbody spectral radiation intensity, in W·m -2 mm 1 ; is the Stefan-Boltzmann constant (5.67×10 -8 W·m -2 ·K -4 ), is the first radiation constant of Planck's law, 3.742×10 -16 W·m 2 , ; is the second radiation constant of Planck's law, 1.438×10 -2 m·K, =hck B -1 , L is the stroke length. It should be noted that in formula (9) Here, represents the absorption coefficient of the sample gas mixture, but in practical applications, it also represents the absorption coefficient of the gas mixture. Therefore, the absorption coefficient of the gas mixture, the path length, and the absolute temperature can be substituted into the total emissivity expression to obtain the triatomic gas emissivity.

[0033] S104, determining the flame blackness of the combustion boiler by the triatomic gas emissivity.

[0034] The method for determining the flame blackness of a combustion boiler based on the emissivity of a triatomic gas includes: using Bell's law and the emissivity of the triatomic gas to calculate the radiation attenuation coefficient; performing nonlinear fitting on the radiation attenuation coefficient to obtain a correction formula for the radiation attenuation coefficient of the triatomic gas in an air combustion atmosphere boiler under a low-pressure environment; and calculating the flame blackness in the air combustion atmosphere boiler under a low-pressure environment based on the correction formula.

[0035] Specifically, the emissivity of the triatomic gas is expressed by Bell's law and the radiation attenuation factor In connection, the formula is as follows: (11); in, is the triatomic gas emissivity; is the radiation attenuation coefficient; It is the sum of the partial pressures of the three atomic gases, in MPa; is the thickness of the effective radiation layer, in meters.

[0036] According to formula (11), we can get , and the radiation attenuation coefficient is obtained.

[0037] The radiation attenuation coefficient of triatomic gas obtained by standard thermal calculation method under normal pressure air conditions is accurate. Its calculation formula is as follows: (12); in, , represents the total mole fraction of triatomic gases CO2 and H2O in flue gas, which comes from the calculation of flue gas properties; Indicates the mole fraction of H2O in the triatomic gas, which comes from the calculation of flue gas properties; Indicates the mole fraction of CO2 in triatomic gas, which comes from the calculation of flue gas properties; Indicates the total flue gas pressure in the furnace, MPa; Indicates the thickness of the effective radiation layer, in m; Indicates the flue gas temperature at the furnace outlet, in K.

[0038] The self-programming method was used to calculate the radiation attenuation coefficient of the triatomic gas when the travel lengths were 0.1m, 1m, and 10m, respectively. The emissivity obtained using the Line-By-Line (LBL) method as the benchmark model was used to infer the radiation attenuation coefficient of the triatomic gas. , and the radiation attenuation coefficient of the triatomic gas obtained by the standard thermodynamic calculation method applicable to atmospheric pressure air conditions Compare and verify the radiation attenuation coefficient derived from the emissivity , and then to the low pressure combustion conditions Is the idea of ​​making a correction feasible?

[0039] The radiation attenuation coefficient is nonlinearly fitted to obtain a correction formula for the radiation attenuation coefficient of triatomic gases in an air combustion atmosphere boiler under a low-pressure environment, including: calculating the radiation attenuation coefficient at various temperatures, various gas partial pressures, and different mole fractions; the radiation attenuation coefficient is nonlinearly fitted to obtain a correction formula for the radiation attenuation coefficient of triatomic gases in flue gas of an air combustion atmosphere boiler under a low-pressure environment.

[0040] The thickness of the effective radiation layer of the power plant boiler is different. Different stroke lengths are used to fully reflect the thickness of the effective radiation layer of the boiler furnace. The stroke lengths are selected as 0.1m, 1m and 10m; the temperature range is selected from 500K to 3000K to fully cover the boiler combustion conditions; the pressure is selected as P=100KPa, 90KPa, 80KPa, 70KPa and 60KPa; different mole fraction ratios are used to reflect the differences in combustion products; the radiation attenuation coefficient of the triatomic gas obtained under different stroke lengths, temperatures, pressures and mole fraction ratios is calculated using self-programming The calculation results are as follows: Figure 2 and Figure 3 As shown, Figure 2 This is a schematic diagram of the calculation results of the radiation attenuation coefficient of the triatomic gas obtained under different path lengths, temperatures, pressures, and when the mole fraction is 1. Figure 3 This is a schematic diagram of the calculation results of the radiation attenuation coefficient of the triatomic gas obtained under different path lengths, temperatures, pressures, and when the mole fraction is 2. Figure 2 and Figure 3 It includes the triatomic gas radiation attenuation coefficient obtained by the modified thermodynamic calculation method, the triatomic gas radiation attenuation coefficient obtained by the standard thermodynamic calculation method, and the triatomic gas radiation attenuation coefficient obtained by using the LBL method as the benchmark model.

[0041] Depend on Figure 2 and Figure 3 It can be seen that the results obtained by the standard thermal calculation method under normal pressure are basically consistent with those obtained by the LBL method, but there is a significant deviation when the pressure is reduced. Therefore, the calculation method provided in the thermal calculation standard is not suitable for low-pressure combustion. A nonlinear fitting is performed and fitted into a form similar to the calculation formula in the thermal calculation method. Finally, the correction formula for the radiation attenuation coefficient of the triatomic gas of the boiler flue gas in the air combustion atmosphere under low pressure environment is obtained as follows: (13).

[0042] Therefore, the flame blackness in the air combustion atmosphere boiler under low pressure environment is calculated according to the correction formula, including: establishing the flame blackness calculation formula and the boiler furnace effective radiation layer thickness calculation formula; substituting the boiler parameters into the correction formula, the flame blackness calculation formula and the boiler furnace effective radiation layer thickness calculation formula to calculate the flame blackness.

[0043] Among them, the main radiation media in the flame under the air combustion atmosphere are triatomic gases CO2 and H2O and carbon black particles. There will be spectral overlap between CO2 and H2O, so the flame blackness needs to be corrected: in heat transfer, the flame is regarded as a gray body, and the calculation formula of flame blackness is in principle: (14); in, For flame blackness, is the furnace pressure, in MPa; is the flame radiation attenuation coefficient, unit is (m·MPa) -1 ; is the thickness of the effective radiation layer, in meters.

[0044] Among them, the calculation formula for the effective radiation layer thickness of the boiler furnace is as follows: (15); in, is the furnace volume, in m 3 ; is the furnace wall area, in m 2 .

[0045] By correcting the flame radiation attenuation factor To correct the flame blackness, the algebraic sum of the radiation attenuation coefficients of various radiation media in the flame is called the flame radiation attenuation coefficient , which is the sum of the radiation attenuation coefficients of triatomic gases, ash particles and coke particles, with the unit of 1 / (m·MPa). The main difference between the radiation characteristics of triatomic gases in the flue gas of air combustion atmosphere boilers in high altitude and low pressure environments and air combustion atmosphere boilers under normal pressure is that the radiation attenuation coefficients of ash particles and coke particles do not need to be corrected.

[0046] The present invention provides a thermal calculation method for a combustion boiler in a low-pressure environment, comprising obtaining the emissivity of a triatomic gas by constructing a triatomic gas emissivity database; obtaining a radiation attenuation coefficient according to Bell's law and the emissivity of the triatomic gas; performing nonlinear fitting on the radiation attenuation coefficient to obtain a correction formula for the radiation attenuation coefficient of the triatomic gas of the flue gas of an air combustion atmosphere boiler in the low-pressure environment; calculating the flame blackness in the air combustion atmosphere boiler in the low-pressure environment according to the correction formula, thereby calculating the flame blackness of the boiler in the low-pressure environment, which can improve calculation efficiency and accuracy and reduce the workload of engineering personnel.

[0047] When applying the thermal calculation method for combustion boilers in a low pressure environment provided by the present invention, it is not necessary to Figure 1 The steps are executed in the order shown. The specific execution order of the steps can be determined according to needs, and the present invention does not limit this.

[0048] The above is a method for calculating the thermal power of a combustion boiler under a low pressure environment provided by one or more embodiments of the present invention. Based on the same idea, the present invention also provides a corresponding device for calculating the thermal power of a combustion boiler under a low pressure environment, such as Figure 4 shown.

[0049] Figure 4 A schematic diagram of a thermal calculation device for a combustion boiler in a low pressure environment provided by the present invention, the device 400 includes: The first determination module 401 is used to determine the absorption coefficient of each participating gas in the combustion boiler under a low pressure environment according to the functional relationship between the spectral parameter of the gas and the absorption coefficient.

[0050] The second determination module 402 is used to determine the absorption coefficient of the mixed gas in the combustion boiler according to the absorption coefficient of each participating gas.

[0051] The third determination module 403 is used to determine the triatomic gas emissivity from a pre-constructed triatomic gas emissivity database according to the absorption coefficient, the stroke length and the absolute temperature of the mixed gas; the stroke length is the effective radiation layer thickness of the combustion boiler.

[0052] The fourth determination module 404 is used to determine the flame blackness of the combustion boiler through the triatomic gas emissivity.

[0053] For the specific definition of the thermal calculation device for a combustion boiler under a low-pressure environment, please refer to the definition of the thermal calculation method for a combustion boiler under a low-pressure environment mentioned above, which will not be repeated here. Each module in the above-mentioned thermal calculation device for a combustion boiler under a low-pressure environment can be implemented in whole or in part by software, hardware, and a combination thereof. The above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory of the computer device in the form of software, so that the processor can call and execute the operations corresponding to the above modules.

[0054] The present invention also provides a computer-readable storage medium, which stores a computer program, which can be used to execute the above Figure 1 Thermodynamic calculation method of combustion boiler under low pressure environment is provided.

[0055] The present invention also provides Figure 5 The structural diagram of the computer device shown in FIG. Figure 5 As shown in the figure, at the hardware level, the computer device includes a processor, an internal bus, a network interface, a memory, and a non-volatile memory, and may also include other hardware required for the business. The processor reads the corresponding computer program from the non-volatile memory into the memory and then runs it to achieve the above Figure 1 Thermodynamic calculation method of combustion boiler under low pressure environment is provided.

[0056] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided by the present invention can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory or optical memory, etc. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0057] The technical features of the above embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of the present invention.

Claims

1. A thermal calculation method for a combustion boiler under a low pressure environment, characterized in that: include: According to the functional relationship between the spectral parameters and the absorption coefficient of the gas, the absorption coefficient of each participating gas in the combustion boiler under low pressure environment is determined; Determining the absorption coefficient of the mixed gas in the combustion boiler according to the absorption coefficient of each participating gas; Determining the triatomic gas emissivity from a pre-constructed triatomic gas emissivity database according to the absorption coefficient, the travel length and the absolute temperature of the mixed gas; the travel length being the effective radiation layer thickness of the combustion boiler; The flame blackness of the combustion boiler is determined by the triatomic gas emissivity.

2. The method according to claim 1, characterized in that According to the functional relationship between the spectral parameters and the absorption coefficient of the gas, the absorption coefficient of each participating gas in the combustion boiler under low pressure environment is determined, including: Obtaining an absorption spectrum of each participating gas during combustion of the boiler; The spectral parameters of each of the absorption spectra are respectively substituted into the functional relationship between the spectral parameters of the gas and the absorption coefficient to obtain the absorption coefficient of each of the participating gases.

3. The method according to claim 1, characterized in that Spectral parameters include partial pressure of gas, degeneracy factor, degeneracy, spectral line center wave number, pressure broadening half width, Doppler broadening half width, air broadening half width and self-broadening half width; The functional relationship between spectral parameters and absorption coefficient includes: ； ； ； ； ； ； ； in, For the The absorption coefficient of the absorption spectrum, is the molecular number density of the gas, For the The intensity of the absorption spectrum line, For the The linear function of the spectral line, is Avogadro's constant, is the gas constant, is the partial pressure of the gas, is the absolute temperature of the gas; is the reference temperature, is Planck's constant, is the lower energy level representing the transition, is the vibrational partition function, is the rotation allocation function, is the speed of light in vacuum, is the Boltzmann constant, is the degeneracy factor; is the degree of simplicity, is the rotation energy level, is the vibration energy level, is the spectral line wave number, is the central wave number of the spectral line, The half width is increased by pressure. is the Doppler half-width, Add half a width to the air, is the self-augmented half-width, is the partial pressure of the participating gases, is the temperature dependence of the half-width of the air widening.

4. The method according to claim 3, characterized in that The process of constructing the functional relationship between spectral parameters and absorption coefficients includes: Based on the line-by-line method and high-resolution spectral database, the functional relationship between the spectral parameters of the gas and the absorption coefficient is established.

5. The method according to claim 3, characterized in that: The triatomic gas emissivity database includes a total emissivity expression; determining the triatomic gas emissivity from a pre-constructed triatomic gas emissivity database according to the absorption coefficient, the path length, and the absolute temperature of the mixed gas, including: The absorption coefficient, path length and absolute temperature of the mixed gas are substituted into the total emissivity expression to obtain the triatomic gas emissivity.

6. The method according to claim 5, characterized in that The process of constructing the total emissivity expression includes: Obtaining sample spectral parameters from a spectral database, and determining the absorption coefficient of the sample mixed gas through a functional relationship between the spectral parameters of the gas and the absorption coefficient; According to the absorption coefficient, path length and absolute temperature of the sample mixed gas, a total emissivity expression is constructed; the total emissivity expression is: ； ； in, is the triatomic gas emissivity, is the blackbody spectral radiation intensity, is the absorption coefficient of the sample gas mixture, is the Stefan-Boltzmann constant, is the first radiation constant of Planck's law, is the second radiation constant of Planck's law, L is the stroke length.

7. The method according to claim 1, characterized in that Determining the absorption coefficient of the mixed gas in the combustion boiler according to the absorption coefficient of each participating gas includes: The absorption coefficients of the participating gases are summed to determine the absorption coefficient of the mixed gas.

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