Method for calculating amount of flue gas from coal gas and coal powder mixed combustion furnace

Abstract

The application discloses a method for measuring and calculating the flue gas quantity of a gas-coal mixed combustion furnace, which comprises the following steps: obtaining effective original data by field measurement and chemical analysis, wherein the effective original data comprises flue gas composition data, and the flue gas composition data comprises the volume content percentage of CO2 in the wet composition of flue gas; calculating the volume quantity of CO2 generated by complete combustion of gas and the volume quantity of CO2 generated by complete combustion of coal powder respectively according to the effective original data; and obtaining the flue gas quantity of the gas-coal mixed combustion furnace according to the volume quantity of CO2 generated by complete combustion of gas, the volume quantity of CO2 generated by complete combustion of coal powder and the volume content percentage of CO2 in the wet composition of flue gas. The method disclosed by the application overcomes the difficulty that the flue gas quantity of the gas-coal mixed combustion furnace cannot be obtained due to the lack of flue gas metering or inaccurate metering in the prior art, and ensures the normal performance of heat balance test work.

Description

Technical Field

[0001] This invention belongs to the field of boiler technology in thermal energy engineering, and particularly relates to a method for calculating the flue gas volume of a co-fired furnace for coal gas and pulverized coal. Background Technology

[0002] In recent years, pulverized coal boilers that co-fire coal gas have been successfully applied and gradually promoted in some steel plants. Moreover, not only pulverized coal boilers that co-fire coal gas boilers, using both coal gas and pulverized coal as fuels, are becoming increasingly common. Co-fired coal gas boilers effectively reduce the emission rate of coal gas; and from the perspective of steel plants, using co-fired coal gas allows for better utilization of coal gas and helps achieve a balance in the coal gas pipeline network; furthermore, after pulverized coal is co-fired with coal gas, SO2 and NO... x The emissions of dust and particulate matter are significantly reduced compared to traditional pulverized coal boilers.

[0003] Furnace heat balance testing is a scientific method for enterprises to analyze the energy distribution and utilization level of heating furnaces. It is an important foundation for improving energy efficiency, optimizing energy management systems, and reducing energy consumption. It is also an important scientific basis for enterprises to formulate energy-saving and consumption-reducing measures and conduct enterprise development planning. Flue gas volume is an important thermal parameter for calculating heat expenditure in heat balance testing.

[0004] In the metallurgical industry, industrial furnaces that co-fire coal gas and pulverized coal are typically designed to control the amount of combustion air during combustion. This prevents incomplete combustion of coal gas and pulverized coal, thus avoiding chemical heat loss. In other words, the flue gas generally does not contain combustible substances such as carbon monoxide and hydrocarbons. However, co-fired coal gas furnaces often lack flue gas metering or have inaccurate metering, which makes it impossible to conduct heat balance tests properly.

[0005] Therefore, it is necessary to design a method for calculating the flue gas volume of a co-firing furnace for coal gas and pulverized coal. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention proposes a method for calculating the flue gas volume in a gas-coal co-firing furnace. This method solves the technical problem in existing technologies where the lack of or inaccurate flue gas metering in gas-coal co-firing furnaces prevents the normal conduct of heat balance testing.

[0007] This invention discloses a method for calculating the flue gas volume in a co-firing furnace of coal gas and pulverized coal, comprising the following steps:

[0008] Valid raw data are obtained through on-site measurement and laboratory analysis. The valid raw data includes flue gas composition data, which includes the volume percentage of CO2 in the wet component of the flue gas.

[0009] Based on the valid raw data, calculate the volume of CO2 produced by the complete combustion of coal gas and the volume of CO2 produced by the complete combustion of pulverized coal, respectively.

[0010] The amount of flue gas from the co-fired coal gas furnace is obtained based on the volume of CO2 produced by the complete combustion of the coal gas, the volume of CO2 produced by the complete combustion of the pulverized coal, and the percentage of CO2 volume content in the wet component of the flue gas.

[0011] According to one embodiment of the present invention, the flue gas composition data further includes the volume percentages of O2, N2, and H2O in the wet component of the flue gas.

[0012] According to one embodiment of the present invention, the effective raw data further includes gas consumption, pulverized coal consumption, gas composition data, pulverized coal composition data, and ash composition data.

[0013] According to one embodiment of the present invention, the gas composition data includes the wet components of the gas, namely CO, H2, CH4, and C. n H m The volume percentages of CO2, O2, N2, and H2O; the coal powder composition data includes the mass percentages of carbon (C), hydrogen (H), oxygen (O), nitrogen (N), sulfur (S), moisture (W), and ash (A) based on the coal powder received; the ash composition data includes the amount of coal ash generated, the mass percentage of carbon in the coal ash, the amount of fly ash generated, and the mass percentage of carbon in the fly ash.

[0014] According to one embodiment of the present invention, the formula for calculating the volume of CO2 produced by the complete combustion of the coal gas is as follows:

[0015]

[0016] Where V1 is the volume of CO2 produced by the complete combustion of coal gas, m 3 / h;B g For gas consumption, m 3 / h; The percentages (%) of CO, CO2, and CH4 by volume in the wet composition of coal gas; ∑nC n H m The wet component of coal gas contains all hydrocarbons C n H m Total volume percentage, %.

[0017] According to one embodiment of the present invention, the formula for calculating the volume of CO2 produced by the complete combustion of pulverized coal is as follows:

[0018]

[0019] Where V2 is the volume of CO2 produced by the complete combustion of pulverized coal, m 3 / h;B s Coal powder consumption, kg / h; C ar The percentage of carbon by mass of pulverized coal received, %; M is the amount of slag generated, kg / h; C M is the percentage of carbon by mass in the coal slag, %; F is the amount of fly ash generated, kg / h; C F The percentage of carbon by mass in fly ash, %.

[0020] According to one embodiment of the present invention, the flue gas volume of the co-firing furnace for coal gas and pulverized coal is calculated using the following formula:

[0021]

[0022] Among them, V y The volume of flue gas from a co-firing furnace for coal gas and pulverized coal is expressed in m³. 3 / h; V1 is the volume of CO2 produced by the complete combustion of coal gas, m 3 / h; V2 is the volume of CO2 produced by the complete combustion of pulverized coal, in m 3 / h; The percentage by volume of CO2 in the wet component of flue gas.

[0023] According to one embodiment of the present invention, an opening is made in the flue of a gas and pulverized coal co-firing furnace, and the flue gas composition data is obtained using a portable flue gas composition analyzer.

[0024] By adopting the above technical solution, the present invention has at least the following beneficial effects:

[0025] The method for calculating the flue gas volume of a gas-coal co-firing furnace provided by this invention obtains effective raw data through on-site measurement and laboratory analysis. Based on the effective raw data, the volume of CO2 produced by the complete combustion of gas and the volume of CO2 produced by the complete combustion of pulverized coal are calculated separately. Finally, the volume percentage of CO2 in the wet composition of the obtained flue gas is used to obtain the flue gas volume of the gas-coal co-firing furnace. This method overcomes the difficulty of obtaining the flue gas volume of the gas-coal co-firing furnace due to the lack of flue gas metering or inaccurate metering in existing technologies. This ensures the normal progress of heat balance testing and provides reference data for energy-saving measures in gas-coal co-firing furnaces. Furthermore, the method provided by this invention is simple to operate and easy to implement. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a flowchart illustrating a method for calculating the flue gas volume in a co-firing furnace of coal gas and pulverized coal, as disclosed in an embodiment of the present invention. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to specific examples and the accompanying drawings.

[0029] It should be noted that all uses of "first" and "second" in the embodiments of the present invention are for the purpose of distinguishing two entities or parameters with the same name but different names. It is clear that "first" and "second" are only for the convenience of expression and should not be construed as limiting the embodiments of the present invention. Subsequent embodiments will not explain this in detail.

[0030] As shown in the figure, an embodiment of the present invention discloses a method for calculating the flue gas volume of a co-firing furnace for coal gas and pulverized coal, comprising the following steps:

[0031] Valid raw data were obtained through on-site measurement and laboratory analysis. Valid raw data included flue gas composition data, which included the volume percentage of CO2 in the wet component of the flue gas.

[0032] Based on valid raw data, calculate the volume of CO2 produced by the complete combustion of coal gas and the volume of CO2 produced by the complete combustion of pulverized coal, respectively.

[0033] The amount of flue gas in a co-fired coal gas and pulverized coal furnace is obtained based on the volume of CO2 produced by the complete combustion of coal gas, the volume of CO2 produced by the complete combustion of pulverized coal, and the percentage of CO2 volume content in the wet component of the flue gas.

[0034] In some embodiments, the flue gas composition data may also include the volume percentages of O2, N2, and H2O in the wet component of the flue gas.

[0035] In some embodiments, the valid raw data also includes gas consumption, pulverized coal consumption, gas composition data, pulverized coal composition data, and ash composition data.

[0036] In some embodiments, the gas composition data includes the wet components of the gas, such as CO, H2, CH4, and C. n H mThe volume percentages of CO2, O2, N2, and H2O; the coal powder composition data includes the mass percentages of carbon (C), hydrogen (H), oxygen (O), nitrogen (N), sulfur (S), moisture (W), and ash (A) on the basis of coal powder; the ash and slag composition data includes the amount of coal slag generated, the mass percentage of carbon in the coal slag, the amount of fly ash generated, and the mass percentage of carbon in the fly ash.

[0037] In some embodiments, the formula for calculating the volume of CO2 produced by the complete combustion of coal gas is:

[0038]

[0039] Where V1 is the volume of CO2 produced by the complete combustion of coal gas, m 3 / h;B g For gas consumption, m 3 / h; The percentages (%) of CO, CO2, and CH4 by volume in the wet composition of coal gas; ∑nC n H m The wet component of coal gas contains all hydrocarbons C n H m Total volume percentage, %.

[0040] In some embodiments, the formula for calculating the volume of CO2 produced by the complete combustion of pulverized coal is:

[0041]

[0042] Where V2 is the volume of CO2 produced by the complete combustion of pulverized coal, m 3 / h;B s Coal powder consumption, kg / h; C ar The percentage of carbon by mass of pulverized coal received, %; M is the amount of slag generated, kg / h; C M is the percentage of carbon by mass in the coal slag, %; F is the amount of fly ash generated, kg / h; C F The percentage of carbon by mass in fly ash, %.

[0043] In some embodiments, the flue gas volume of the co-firing furnace for coal gas and pulverized coal is calculated using the following formula:

[0044]

[0045] Among them, V y The volume of flue gas from a co-firing furnace for coal gas and pulverized coal is expressed in m³. 3 / h; V1 is the volume of CO2 produced by the complete combustion of coal gas, m 3 / h; V2 is the volume of CO2 produced by the complete combustion of pulverized coal, in m3 / h; The percentage by volume of CO2 in the wet component of flue gas.

[0046] In some embodiments, an opening is made in the flue of a gas-pulverized coal co-firing furnace, and a portable flue gas composition analyzer is used to obtain the flue gas composition data.

[0047] According to an embodiment of the present invention, the method for calculating the flue gas volume in a co-firing furnace of coal gas and pulverized coal includes the following steps:

[0048] Step 1: Collect the following data during the testing of gas and pulverized coal: gas consumption (Bg), pulverized coal consumption (Bs), and the wet composition of the gas (CO, H2, CH4, C). n H m Volume percentages of CO2, O2, N2, and H2O; mass percentages of carbon (C), hydrogen (H), oxygen (O), nitrogen (N), sulfur (S), moisture (W), and ash (A) based on coal composition; amount of coal slag (M) and carbon content (C) in the coal slag. M .

[0049] Step 2: Open holes in the flue gas and pulverized coal ducts, and use testing instruments to obtain the volume percentages of CO2, O2, N2, and H2O in the wet composition of the flue gas; and the amount of fly ash generated (F) and the carbon content (C) in the fly ash. F .

[0050] Step 3: Based on the carbon balance before and after combustion, determine the flue gas volume V using the following formula. y :

[0051]

[0052] Among them, B g This represents the consumption of coal gas, expressed in cubic meters (m³). 3 / h, B s This represents the consumption of pulverized coal, expressed in kg / h.

[0053] ∑nC represents the volume percentages of CO, CO2, and CH4 in the wet components of coal gas. n H m The wet component of coal gas contains all hydrocarbons C n H m Total volume percentage, %, in %.

[0054] The percentage of carbon dioxide by volume in the wet component of flue gas, expressed as %.

[0055] M and F represent the amount of slag and fly ash generated, respectively, in kg / h.

[0056] C M C F The values ​​are the percentage of carbon content by mass in coal slag and fly ash, respectively, in %.

[0057] Example 1

[0058] The gas consumption during the testing of the gas-coal co-firing furnace was B. g =3800m 3 / h; the consumption of pulverized coal is B s =570kg / h; slag production M = 70kg / h, carbon content C in slag M The carbon content is 1%; the fly ash generation rate F is 7 kg / h, and the carbon content C in the fly ash is... M The wet composition of the coal gas, the wet composition of the flue gas after the flue gas duct is opened, and the composition of the pulverized coal received as a basis are shown in Tables 1, 2, and 3 below, respectively.

[0059] Table 1. Wet composition of coal gas

[0060]

[0061] Table 2. Wet composition of flue gas

[0062]

[0063] Table 3 Composition of Pulverized Coal (Received Basis)

[0064]

[0065] The result obtained from step 3 above is: the flue gas volume V of the co-firing furnace for coal gas and pulverized coal. y 12841m 3 / h.

[0066] Example 2

[0067] The gas consumption during the testing of the gas-coal co-firing furnace was B. g =4200m 3 / h; the consumption of pulverized coal is B s =430kg / h; slag production M = 68kg / h, carbon content C in slag M The carbon content is 0.7%; the fly ash generation rate F is 4.7 kg / h, and the carbon content C in the fly ash is... M The wet composition of the coal gas, the wet composition of the flue gas after the flue gas duct is opened, and the composition of the pulverized coal received basis are shown in Tables 1, 2, and 3 below.

[0068] Table 1. Wet composition of coal gas

[0069]

[0070] Table 2. Wet composition of flue gas

[0071]

[0072] Table 3 Composition of Pulverized Coal (Received Basis)

[0073]

[0074] The result obtained from step 3 above is: the flue gas volume V of the co-firing furnace for coal gas and pulverized coal. y 15593m 3 / h.

[0075] In summary, the method for calculating the flue gas volume of a gas-coal co-firing furnace provided by this invention obtains effective raw data through on-site measurement and laboratory analysis. Based on this data, the volume of CO2 produced by the complete combustion of gas and the volume of CO2 produced by the complete combustion of pulverized coal are calculated. Finally, the volume percentage of CO2 in the wet composition of the obtained flue gas is used to obtain the flue gas volume of the gas-coal co-firing furnace. This overcomes the difficulty of obtaining the flue gas volume of the gas-coal co-firing furnace due to the lack of flue gas metering or inaccurate metering in existing technologies. This ensures the normal progress of heat balance testing and provides reference data for energy-saving measures in gas-coal co-firing furnaces. Furthermore, the method provided by this invention is simple to operate and easy to implement.

[0076] It should be noted that the components or steps in the above embodiments can be interchanged, substituted, added, or deleted. Therefore, the combinations formed by these reasonable permutations and transformations should also fall within the protection scope of this invention, and the protection scope of this invention should not be limited to the above embodiments.

[0077] The above are exemplary embodiments disclosed in this invention. The order of the disclosed embodiments is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. However, it should be noted that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the disclosed embodiments of this invention (including the claims) is limited to these examples. Various changes and modifications can be made without departing from the scope defined by the claims. The functions, steps, and / or actions of the methods according to the disclosed embodiments described herein do not need to be performed in any particular order. Furthermore, although the elements disclosed in the embodiments of this invention may be described or claimed individually, they may be understood as multiple unless explicitly limited to a singular.

[0078] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples. Within the framework of the invention, technical features of the above embodiments or different embodiments can be combined, and many other variations of the different aspects of the invention as described above exist, which are not provided in the details for the sake of brevity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the protection scope of the invention.

Claims

1. A method for calculating the flue gas volume in a co-firing furnace of coal gas and pulverized coal, characterized in that, Includes the following steps: Valid raw data are obtained through on-site measurement and laboratory analysis. The valid raw data includes flue gas composition data, coal gas consumption, coal powder consumption, coal gas composition data, coal powder composition data, and ash composition data. The flue gas composition data includes the volume percentage of CO2 in the wet component of the flue gas. Based on the valid raw data, calculate the volume of CO2 produced by the complete combustion of coal gas and the volume of CO2 produced by the complete combustion of pulverized coal, respectively. The amount of flue gas from the co-fired coal gas furnace is obtained based on the volume of CO2 produced by the complete combustion of the coal gas, the volume of CO2 produced by the complete combustion of the pulverized coal, and the percentage of CO2 volume content in the wet component of the flue gas. The formula for calculating the volume of CO2 produced by the complete combustion of the coal gas is as follows: Where V1 is the volume of CO2 produced by the complete combustion of coal gas, m 3 / h;B g For gas consumption, m 3 / h; , , The percentages (%) of CO, CO2, and CH4 in the wet composition of coal gas are respectively. The wet component of coal gas contains all hydrocarbons C n H m Total volume percentage, % The formula for calculating the volume of CO2 produced by the complete combustion of pulverized coal is: Where V2 is the volume of CO2 produced by the complete combustion of pulverized coal, m 3 / h;B s Coal powder consumption, kg / h; C ar C represents the percentage of carbon content by mass of pulverized coal (%), M represents the amount of slag generated (kg / h), and C represents the amount of carbon in the coal slag. M C represents the percentage of carbon by mass in the coal slag (%), F represents the amount of fly ash generated (kg / h), and C represents the amount of fly ash generated (%). F The percentage of carbon by mass in fly ash.

2. The method for calculating the flue gas volume of a co-firing furnace for coal gas and pulverized coal according to claim 1, characterized in that, The flue gas composition data also includes the volume percentages of O2, N2, and H2O in the wet component of the flue gas.

3. The method for calculating the flue gas volume of a co-firing furnace for coal gas and pulverized coal according to claim 1, characterized in that, The gas composition data includes the wet components of the gas, namely CO, H2, CH4, and C. n H m The volume percentages of CO2, O2, N2, and H2O; the coal powder composition data includes the mass percentages of carbon (C), hydrogen (H), oxygen (O), nitrogen (N), sulfur (S), moisture (W), and ash (A) based on the coal powder received; the ash composition data includes the amount of coal ash generated, the mass percentage of carbon in the coal ash, the amount of fly ash generated, and the mass percentage of carbon in the fly ash.

4. The method for calculating the flue gas volume of a co-firing furnace for coal gas and pulverized coal according to claim 1, characterized in that, The flue gas volume of the co-firing furnace for coal gas and pulverized coal is calculated using the following formula: Among them, V y The volume of flue gas from a co-firing furnace for coal gas and pulverized coal is expressed in m³. 3 / h; V1 is the volume of CO2 produced by the complete combustion of coal gas, m 3 / h; V2 is the volume of CO2 produced by the complete combustion of pulverized coal, in m 3 / h; The percentage by volume of CO2 in the wet component of flue gas.

5. The method for calculating the flue gas volume of a co-firing furnace for coal gas and pulverized coal according to claim 1, characterized in that, By opening a duct in the gas and pulverized coal co-firing furnace, the flue gas composition data is obtained using a portable flue gas composition analyzer.

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