CN-121977202-A - Energy efficiency evaluation method and equipment for sintering flue gas combustion-supporting circulating fluidized bed boiler

CN121977202ACN 121977202 ACN121977202 ACN 121977202ACN-121977202-A

Abstract

The application discloses an energy efficiency evaluation method and equipment for a sintering flue gas combustion-supporting circulating fluidized bed boiler. The method comprises the steps of determining an excess flue gas coefficient based on components of sintering flue gas and a carbon monoxide combustion oxygen consumption law, determining a theoretical flue gas amount based on the components of the sintering flue gas, a sulfur-containing component of fuel and a calcium-containing component of a desulfurizing agent, the excess flue gas coefficient and a dual-source sulfur balance principle of fuel and flue gas, determining comprehensive heat loss according to the theoretical flue gas amount, the excess flue gas coefficient and the combustible content of boiler ash, the thermal physical characteristics of the sintering flue gas and boiler outlet flue gas, the desulfurization reaction influence and the boiler operation parameters, determining the fuel efficiency and the heat efficiency of the sintering flue gas combustion-supporting circulating fluidized bed boiler according to the comprehensive heat loss, sensible heat carried by the sintering flue gas and the heat released by carbon monoxide combustion in the sintering flue gas, and completing the energy efficiency rating of the sintering flue gas combustion-supporting circulating fluidized bed boiler based on the fuel efficiency and the heat efficiency and by combining preset energy efficiency rating standards.

Inventors

LI YUANYUAN
LI JINJING
ZHAO ZHENNING
DONG ZHAOMIN
SONG YUNCHANG
Jia Xiaopi

Assignees

华北电力科学研究院有限责任公司
国家电网有限公司

Dates

Publication Date: 20260505
Application Date: 20260115

Claims (10)

1. The energy efficiency evaluation method of the sintering flue gas combustion-supporting circulating fluidized bed boiler is characterized by comprising the following steps of: collecting the components of sintering flue gas, the sulfur-containing component of fuel, the calcium-containing component of desulfurizing agent and the combustible content of boiler ash; Determining an excessive smoke coefficient based on the components of the sintering smoke and combining a carbon monoxide combustion oxygen consumption rule; determining theoretical flue gas volume based on the components of the sintering flue gas, the sulfur-containing component of the fuel, the calcium-containing component of the desulfurizing agent and the excessive flue gas coefficient by combining the fuel and flue gas dual-source sulfur balance principle; Determining comprehensive heat loss according to the theoretical flue gas amount, the excessive flue gas coefficient and the combustible content of the boiler ash, and combining the thermal physical characteristics of the sintering flue gas and the flue gas of the boiler outlet, the desulfurization reaction influence and the boiler operation parameters; Determining the fuel efficiency and the heat efficiency of the sintering flue gas combustion-supporting circulating fluidized bed boiler according to the comprehensive heat loss, the sensible heat carried by the sintering flue gas and the heat released by the combustion of carbon monoxide in the sintering flue gas; And based on the fuel efficiency and the thermal efficiency, combining a preset energy efficiency grading standard to finish the energy efficiency grading of the sintering flue gas combustion-supporting circulating fluidized bed boiler.
2. The method of claim 1, wherein determining an excess flue gas coefficient based on the composition of the sintering flue gas in combination with a carbon monoxide combustion oxygen consumption law comprises: Respectively converting wet matrix integral numbers of nitrogen, oxygen, carbon monoxide, carbon dioxide and sulfur dioxide in the corresponding flue gas into dry basis volume fractions according to the wet basis volume fractions of water vapor in the sintering flue gas and the flue gas at the outlet of the air preheater; According to the dry basis volume fractions of nitrogen and oxygen in the sintering flue gas, and combining the dry basis volume fractions of carbon monoxide in the sintering flue gas and the combustion reaction proportion of the carbon monoxide and the oxygen, determining the oxygen amount required to be consumed by the combustion of the carbon monoxide in the sintering flue gas; and determining an excess flue gas coefficient by taking the volume fraction of the effective oxygen after subtracting the oxygen amount required to be consumed by the carbon monoxide combustion from the dry basis volume fraction of the oxygen in the sintering flue gas as a benchmark and combining the dry basis volume fractions of the nitrogen and the oxygen in the flue gas at the outlet of the air preheater.
3. The method of claim 2, wherein determining a theoretical flue gas amount based on the composition of the sintering flue gas, the sulfur-containing component of the fuel and the calcium-containing component of the desulfurizing agent, the excess flue gas coefficient, in combination with a fuel and flue gas dual source sulfur balance principle, comprises: According to the dry basis volume fractions of nitrogen and carbon dioxide in the sintering flue gas, and combining the theoretical dry combustion-supporting flue gas volume, calculating the total contribution volume of the nitrogen and the carbon dioxide carried by the sintering flue gas; calculating total sulfur corresponding to double-source sulfur balance according to the mass fraction of the sulfur-containing components of the fuel, the dry basis volume fraction of sulfur dioxide in the sintering flue gas, the theoretical dry combustion-supporting flue gas volume and the excess flue gas coefficient; Calculating the increment contribution of the desulfurization reaction to the flue gas amount by combining the total sulfur amount, the calcium carbonate decomposition rate, the sulfation reaction degree and the calcium-sulfur molar ratio corresponding to the calcium-containing component of the desulfurizing agent; And determining the theoretical flue gas amount according to the total contribution volume of the nitrogen and the carbon dioxide, the basic volume of flue gas generated by fuel combustion and the incremental contribution.
4. The method of claim 1, wherein determining the integrated heat loss based on the theoretical flue gas amount, the excess flue gas coefficient, and the combustible content of the boiler ash, in combination with the sintering flue gas and boiler outlet flue gas thermophysical properties, desulfurization reaction effects, and boiler operating parameters, comprises: Determining the density of the sintering flue gas based on the dry basis volume fraction of each component of the sintering flue gas; Determining the absolute humidity of the sintering flue gas based on the integral number of wet matrixes of each component of the water vapor and the sintering flue gas; Determining heat taken away by the dry basis components of the outlet flue gas of the air preheater according to the theoretical flue gas quantity, the excess flue gas coefficient and the average specific constant pressure heat capacity of the dry basis components of the outlet flue gas of the air preheater and by combining the difference value of the temperature of the outlet flue gas of the air preheater and the reference temperature; Determining the heat carried by the water vapor according to the density of the sintering flue gas, the absolute humidity of the sintering flue gas, the theoretical flue gas amount, the excess flue gas coefficient and the average ratio constant pressure heat capacity of the water vapor and combining the difference value of the flue gas temperature at the outlet of the air preheater and the reference temperature; and adding the heat taken away by the dry base component of the flue gas at the outlet of the air preheater and the heat carried by the water vapor to obtain the smoke discharging loss.
5. The method of claim 1, wherein determining the integrated heat loss based on the theoretical flue gas amount, the excess flue gas coefficient, and the combustible content of the boiler ash, in combination with the sintering flue gas and boiler outlet flue gas thermophysical properties, desulfurization reaction effects, and boiler operating parameters, further comprises: Determining the mass fraction of total ash generated after adding the desulfurizing agent for each kilogram of the fuel to be charged according to the ash of the fuel to be charged, the ash carried by the desulfurizing agent, the non-decomposed calcium carbonate in the desulfurizing agent, the calcium sulfate generated by the desulfurizing reaction and the mass fraction of the calcium oxide which does not generate the sulfation reaction; And determining physical heat loss of the ash according to the total ash mass fraction, the ratio of the slag to the fly ash accounting for the total ash amount of the fuel, the difference value of the slag temperature and the reference temperature, the difference value of the fly ash temperature and the reference temperature, the average specific pressure heat capacity of the slag, the average specific pressure heat capacity of the fly ash and the combustible mass fraction corresponding to the combustible content of the boiler ash.
6. The method of claim 1, wherein determining the integrated heat loss based on the theoretical flue gas amount, the excess flue gas coefficient, and the combustible content of the boiler ash, in combination with the sintering flue gas and boiler outlet flue gas thermophysical properties, desulfurization reaction effects, and boiler operating parameters, further comprises: determining desulfurization loss according to total sulfur, molar ratio of calcium to sulfur, decomposition rate of calcium carbonate and desulfurization efficiency; According to the volume fractions of carbon monoxide, methane, hydrogen and hydrocarbon in the dry basis components of the outlet flue gas of the air preheater, the dry flue gas volume obtained by calculating the theoretical flue gas volume and the excess flue gas coefficient and the combustion heat characteristics of each combustible gas are combined, and incomplete combustion loss of the gas is determined; According to the total ash mass fraction generated after adding the desulfurizing agent for each kilogram of fuel fed into the furnace, determining the incomplete combustion loss of the solid according to the combustion heat characteristic of the carbon by combining the ash average combustible mass fraction obtained by calculating the combustible content of the boiler ash; And determining the heat dissipation loss according to the heat dissipation loss under the maximum output in the boiler operation parameters and the ratio of the maximum output heat to the actual output heat of the boiler, and determining the boiler surface emissivity coefficient by combining the ratio of the actual surface emissivity of the boiler to the surface emissivity under the standard condition.
7. The method according to any one of claims 4-6, wherein determining the fuel efficiency and the thermal efficiency of the sintering flue gas combustion-supporting circulating fluidized bed boiler from the integrated heat loss, the sensible heat carried by the sintering flue gas itself and the heat released by the combustion of carbon monoxide in the sintering flue gas comprises: Determining sensible heat carried by the sintering flue gas according to the excess flue gas coefficient, the theoretical dry combustion-supporting flue gas volume and the sintering flue gas weighted average ratio constant pressure heat capacity and combining the difference value of the sintering flue gas temperature and the reference temperature; determining the heat released by the combustion of carbon monoxide in the sintering flue gas according to the excess flue gas coefficient, the theoretical dry combustion-supporting flue gas volume and the dry basis volume fraction of carbon monoxide in the sintering flue gas and the combustion heat characteristic of the carbon monoxide; Determining the fuel efficiency of the boiler according to the proportion of the smoke discharging loss, the gas incomplete combustion loss, the solid incomplete combustion loss, the heat dissipation loss, the ash physical heat loss, the desulfurization loss, the sensible heat carried by the sintering flue gas and the heat released by the combustion of carbon monoxide in the sintering flue gas to the low-level calorific value of the fuel entering the boiler; And determining the thermal efficiency of the boiler by taking the sum of the low-level heating value of the fuel entering the boiler, sensible heat carried by the sintering flue gas and heat released by burning carbon monoxide in the sintering flue gas as total input heat and according to the proportion of the smoke discharging loss, the gas incomplete combustion loss, the solid incomplete combustion loss, the heat dissipation loss, the ash physical heat loss and the desulfurization loss to the total input heat.
8. An energy efficiency evaluation device of a sintering flue gas combustion-supporting circulating fluidized bed boiler, which is characterized by comprising: The collecting module is used for collecting components of the sintering flue gas, sulfur-containing components of fuel, calcium-containing components of desulfurizing agent and combustible content of boiler ash; The first determining module is used for determining an excessive flue gas coefficient based on the components of the sintering flue gas and combining a carbon monoxide combustion oxygen consumption rule; the second determining module is used for determining theoretical flue gas quantity based on the components of the sintering flue gas, the sulfur-containing components of the fuel, the calcium-containing components of the desulfurizing agent and the excessive flue gas coefficient and combining the fuel and flue gas double-source sulfur balance principle; the third determining module is used for determining comprehensive heat loss according to the theoretical flue gas amount, the excessive flue gas coefficient and the combustible content of the boiler ash, and combining the thermal physical characteristics of the sintering flue gas and the flue gas of the boiler outlet, the influence of desulfurization reaction and the operation parameters of the boiler; The fourth determining module is used for determining the fuel efficiency and the heat efficiency of the sintering flue gas combustion-supporting circulating fluidized bed boiler according to the comprehensive heat loss, the sensible heat carried by the sintering flue gas and the heat released by the combustion of carbon monoxide in the sintering flue gas; And the evaluation module is used for finishing the energy efficiency rating of the sintering flue gas combustion-supporting circulating fluidized bed boiler based on the fuel efficiency and the thermal efficiency and combining with a preset energy efficiency rating standard.
9. A storage medium, characterized in that the storage medium comprises a stored program, wherein the device in which the storage medium is located is controlled to execute the energy efficiency evaluation method of the sintering flue gas combustion-supporting circulating fluidized bed boiler according to any one of claims 1 to 7 when the program is run.
10. An electronic device, characterized in that the device comprises at least one processor, at least one memory and a bus connected with the processor, wherein the processor and the memory are communicated with each other through the bus, and the processor is used for calling program instructions in the memory to execute the energy efficiency evaluation method of the sintering flue gas combustion-supporting circulating fluidized bed boiler according to any one of claims 1 to 7.

Description

Energy efficiency evaluation method and equipment for sintering flue gas combustion-supporting circulating fluidized bed boiler Technical Field The application relates to the technical field of boilers, in particular to an energy efficiency evaluation method and equipment for a sintering flue gas combustion-supporting circulating fluidized bed boiler. Background The sintering production is an important process unit for modern steel production, a large amount of sintering flue gas containing physical heat, chemical heat and combustible components is generated in the production process, and the flue gas is used as combustion-supporting air to be applied to a circulating fluidized bed boiler, so that the method has become an important mode for recycling flue gas energy and reducing energy consumption in the industry. In the prior art, the core calculation logic of the boiler energy efficiency rating system is constructed based on the traditional air combustion-supporting working condition, the energy input and loss accounting mode is fixedly adapted to the thermophysical characteristics and the components of the air, the sintering flue gas has obvious differences with the air in the aspects of humidity, density, combustible component content and the like, and extra sensible heat and chemical heat can be brought in, so that the traditional rating system cannot be accurately matched with the special energy balance relation of the sintering flue gas combustion-supporting, and finally the true energy efficiency level of the boiler is difficult to objectively and accurately evaluate. Disclosure of Invention In view of the above problems, the application provides an energy efficiency evaluation method and equipment for a sintering flue gas combustion-supporting circulating fluidized bed boiler. In order to solve the technical problems, the application provides the following scheme: The application provides an energy efficiency evaluation method of a sintering flue gas combustion-supporting circulating fluidized bed boiler, which comprises the steps of collecting components of sintering flue gas, sulfur-containing components of fuel, calcium-containing components of desulfurizing agent and combustible content of boiler ash, determining an excessive flue gas coefficient based on the components of the sintering flue gas and a carbon monoxide combustion oxygen consumption law, determining a theoretical flue gas amount based on the components of the sintering flue gas, the sulfur-containing components of fuel and the calcium-containing components of desulfurizing agent, the excessive flue gas coefficient and a fuel and flue gas dual-source sulfur balance principle, determining comprehensive heat loss according to the theoretical flue gas amount, the excessive flue gas coefficient and the combustible content of the boiler ash, combining the thermal physical characteristics of the sintering flue gas and the flue gas at the outlet of the boiler, the desulfurization reaction influence and the boiler operation parameters, determining fuel efficiency and thermal efficiency of the sintering flue gas circulating fluidized bed boiler according to the comprehensive heat loss, sensible heat carried by the sintering flue gas and the heat released by carbon monoxide combustion in the sintering flue gas, and completing the energy efficiency rating of the sintering combustion-supporting circulating fluidized bed boiler based on the fuel efficiency and the thermal efficiency and the preset energy efficiency class division standard. In a second aspect, the present application provides an energy efficiency evaluation device for a sintering flue gas combustion-supporting circulating fluidized bed boiler, the energy efficiency evaluation device for the sintering flue gas combustion-supporting circulating fluidized bed boiler comprising: The collecting module is used for collecting components of the sintering flue gas, sulfur-containing components of fuel, calcium-containing components of desulfurizing agent and combustible content of boiler ash; The first determining module is used for determining an excessive flue gas coefficient based on the components of the sintering flue gas and combining a carbon monoxide combustion oxygen consumption rule; the second determining module is used for determining theoretical flue gas quantity based on the components of the sintering flue gas, the sulfur-containing component of the fuel, the calcium-containing component of the desulfurizing agent and the excessive flue gas coefficient and combining the balance principle of the fuel and the flue gas dual-source sulfur; the third determining module is used for determining comprehensive heat loss according to theoretical flue gas quantity, excessive flue gas coefficient and combustible content of boiler ash, and combining the thermal physical characteristics of the sintering flue gas and the flue gas of the boiler outlet, desulfurization reaction influence a