Simplified selection method for blast furnace gas boiler blower

Abstract

The application discloses a simplified selection method for a blast furnace gas boiler air blower. The method comprises the following steps: calculating the air volume required for burning per cubic meter of blast furnace gas according to the dry basis heat value of the blast furnace gas; calculating the total air volume in the standard state according to the blast furnace gas flow rate; calculating the total air system resistance before the air blower and the total air system resistance after the air blower according to the total air volume in the standard state, local meteorological parameters, air duct parameters and equipment parameters; calculating the actual total air volume according to the local atmospheric pressure and the air inlet temperature of the air blower; calculating the selection air volume of the air blower according to the actual total air volume; and calculating the selection pressure head according to the total air system resistance before the air blower, the total air system resistance after the air blower and the furnace negative pressure. The application can complete the relevant selection calculation only by using the gas heat value, is very convenient, and eliminates the complicated process of traditional detailed calculation which needs a large amount of basic data.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of steel enterprises coal gas power generation, and particularly relates to a simplified selection method of a blast furnace coal gas boiler air blower of a steel enterprise. BACKGROUND

[0002] A large amount of by-product coal gas is generated in the smelting process of a steel enterprise, including blast furnace gas, converter gas, coke oven gas and the like. In addition to being supplied to each smelting process of the steel plant for self-use, a certain amount of the by-product coal gas is in surplus, especially the blast furnace gas. For the surplus coal gas, the steel plant generally recycles and utilizes the surplus coal gas through a coal gas boiler. As an important auxiliary machine of the coal gas boiler, the selection of the air blower is crucial to the economic and safe operation of the unit. However, at present, the selection of the air blower has the following characteristics: first, it is relatively extensive and not reasonable. The air volume of the air blower is closely related to the excess air coefficient. At present, a certain set value is usually taken in engineering, but in fact, the excess air coefficient of coal gas with different calorific values is different (even if the oxygen content is the same), which is a major difference between metallurgical coal gas and conventional fuels such as coal, natural gas and biomass. Second, the coal gas calorific value range can be provided in many projects, but the accurate composition of the coal gas cannot be provided, especially in the early stage of the project, which undoubtedly brings difficulties to the selection of the blast furnace coal gas boiler air blower. Third, the automation level, operation personnel level and unit maintenance and maintenance capacity of different steel plants are different, resulting in different boiler combustion control conditions, and causing the operating parameters of the air blower of the units in the same region, with the same fuel and the same parameters, to be quite different. SUMMARY

[0003] In view of the above defects, the purpose of the present application is to construct a general and rapid selection method for the blast furnace coal gas boiler air blower under limited conditions.

[0004] To achieve the above purpose, a simplified selection method of a blast furnace coal gas boiler air blower of a steel enterprise according to the present application comprises the following steps:

[0005] The air volume required for the combustion of each cubic meter of blast furnace gas is calculated according to the dry basis calorific value of the blast furnace gas;

[0006] The total air volume at the standard state is calculated according to the blast furnace gas flow rate;

[0007] The total resistance of the air system before the air blower and the total resistance of the air system after the air blower are calculated according to the total air volume at the standard state, local meteorological parameters, air duct parameters and equipment parameters;

[0008] The actual total air volume is calculated according to the local atmospheric pressure and the atmospheric temperature at the inlet of the air blower;

[0009] According to the actual total air quantity, the selection air quantity of the air supply fan is calculated, and according to the total resistance of the air system before the air supply fan, the total resistance of the air system after the air supply fan and the furnace negative pressure, the selection pressure head is calculated.

[0010] Further, the specific steps of the method are as follows:

[0011] Step 1: According to the heat value Q of the blast furnace gas d , the air quantity V required for burning per cubic meter of blast furnace gas is calculated k,0 :

[0012] V k,0 =(1+1.61d k )(aQ d +b)

[0013] Wherein, V k,0 is the air quantity required for burning per cubic meter of blast furnace gas, Nm 3 / Nm 3 ; Q d is the dry basis heat value of the blast furnace gas, kJ / Nm 3 ; d k is the absolute humidity of air, kg / kg; a and b are calculation coefficients, wherein a=2.09x10 -4 ~2.13x10 -4 , b=0.09~0.12;

[0014] Step 2: According to the blast furnace gas flow B into the furnace, the standard state total air quantity V k,1 is calculated

[0015] V k,1 =BV k,0

[0016] Wherein, V k,1 is the standard state total air quantity, Nm 3 / h; B is the standard state flow of the blast furnace gas dry basis into the furnace, Nm 3 / h; V k,0 is the air quantity required for burning per cubic meter of blast furnace gas, Nm 3 / Nm 3 ;

[0017] Step 3: According to the standard state total air quantity, the local meteorological parameters, the air duct parameters and the equipment parameters, the total resistance P1 of the air system before the air supply fan and the total resistance P2 of the air system after the air supply fan are calculated.

[0018] Step 4: According to the local atmospheric pressure p0 and the air inlet temperature t0 of the air supply fan, the actual total air quantity V 总 is calculated

[0019]

[0020] wherein V 总 is the actual total air volume, m 3 / h; t0 is the air temperature at the inlet of the air blower, ℃; p0 is the local atmospheric pressure, Pa; P1 is the total resistance of the air system before the air blower, Pa; V k,1 is the standard total air volume, Nm 3 / h;

[0021] Step 5: determining the selected air volume and the selected pressure head of the air blower, specifically as follows:

[0022] 1) the selected air volume V 选型 = 1.1 x k x V 总 / N

[0023] wherein V 选型 is the selected air volume of the air blower, m 3 / h; k is the flow coefficient considering the air leakage at the air supply side of the air preheater after one year of operation; V 总 is the actual total air volume, m 3 / h; N is the number of air blowers;

[0024] 2) the selected pressure head P 选型 = 1.2 x (P1 + P2 + p lt )

[0025] wherein P1 is the total resistance of the air system before the air blower, Pa; P2 is the total resistance of the air system after the air blower, Pa; p lt is the furnace negative pressure (negative value), Pa.

[0026] Further, the blast furnace gas heat value Q d and the blast furnace gas flow B corresponding to the data under the boiler BMCR condition.

[0027] Further, the local meteorological parameters include temperature and humidity, and the average value of the monthly average meteorological parameters at 14:00 of the hottest month in the past years or the data-searchable years is taken.

[0028] Further, the furnace negative pressure p lt is-20 to-50 Pa;

[0029] Further, the excess coefficient k considering the air leakage at the air supply side of the air preheater after one year of operation in step 5 is 1.03.

[0030] To achieve the above purpose, a storage medium of the present application has a computer program stored thereon, and when the computer program is executed by a processor, the above-mentioned simplified selection method of the blast furnace gas boiler air blower of a steel enterprise is realized.

[0031] The application constructs a set of general and rapid selection method of blast furnace gas boiler air blower under limited conditions, which can complete the related selection calculation only by the calorific value of the gas, is very convenient, and avoids the cumbersome process of traditional detailed calculation which needs a large amount of basic data. Moreover, the method provided by the application has good universality, and can be used in steel plants with high operation and maintenance level or high automation degree, and also can be used in steel plants with general operation and maintenance level; can be used for rough selection in the early stage of the project, and also can be used for experience checking of detailed selection in the preliminary design stage, and has strong practical significance. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 The flowchart of the application. DETAILED DESCRIPTION

[0033] The embodiments of the application will be described in detail below with reference to the accompanying drawings.

[0034] In the description of the application, it should be understood that the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application.

[0035] The terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0036] In the description of the application, it should be noted that, unless otherwise specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, can be fixed connection, can also be detachable connection, or integrally connected; can be directly connected, or indirectly connected through an intermediate medium, can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0037] The simplified selection method of the blast furnace gas boiler air blower of the steel enterprise of the application comprises the following steps:

[0038] According to the dry basis calorific value of the blast furnace gas, the air quantity required for the combustion of each cubic meter of blast furnace gas is calculated;

[0039] Calculate the standard state total air volume based on the blast furnace gas flow rate.

[0040] Calculate the total resistance of the air system before the blower and the total resistance of the air system after the blower based on the standard total air volume, local meteorological parameters, duct parameters, and equipment parameters.

[0041] The actual total air volume is calculated based on the local atmospheric pressure and the air temperature at the inlet of the blower.

[0042] The selected air volume of the blower is calculated based on the actual total air volume, and the selected pressure head is calculated based on the total resistance of the air system before the blower, the total resistance of the air system after the blower, and the negative pressure in the furnace.

[0043] This invention constructs a universal and rapid selection method for blast furnace gas boiler blowers under limited conditions. It only requires the calorific value of the gas to complete the relevant selection calculations, which is very convenient and eliminates the tedious process of detailed calculations requiring a large amount of basic data in traditional methods. Furthermore, the method provided by this invention has excellent versatility, applicable to steel plants with high levels of operation and maintenance or high levels of automation, as well as those with average levels of operation and maintenance. It can be used for rough selection in the early stages of a project, as well as for empirical verification of detailed selections in the preliminary design stage, demonstrating strong practical significance.

[0044] The specific steps of an exemplary embodiment of the present invention are as follows:

[0045] Step 1: Based on the calorific value Q of the blast furnace gas d Calculate the air volume V required for combustion of one cubic meter of blast furnace gas. k,0 :

[0046] V k,0 =(1+1.61d) k (aQ) d +b)

[0047] Among them, V k,0 The amount of air required for combustion of one cubic meter of blast furnace gas, Nm 3 / Nm 3 Q d The dry basis calorific value of blast furnace gas is kJ / Nm³. 3 ;d k ρ represents absolute humidity of air, kg / kg; a and b are calculation coefficients. For steel plants with high levels of operation and maintenance or high automation, and which have implemented automatic boiler combustion control, a = 2.093 × 10⁻⁶. -4 b = 0.094. For steel plants with average operation and maintenance levels, relatively extensive management, and no automatic boiler combustion control, a = 2.127 × 10 -4 b = 0.117.

[0048] Step 2: Calculate the total air quantity V in standard state according to the BF gas flow B into the furnace k,1 :

[0049] V k,1 = BV k,0

[0050] Wherein, V k,1 is the total air quantity in standard state, Nm 3 / h; B is the BF gas flow in standard state, Nm 3 / h; V k,0 is the air quantity required for burning per cubic meter of BF gas, Nm 3 / Nm 3 ;

[0051] The BF gas heat value Q d and the BF gas flow B into the furnace correspond to the data under the BMCR condition of the boiler.

[0052] Step 3: Calculate the total air system resistance P1 before the air blower and the total air system resistance P2 after the air blower according to the total air quantity in standard state, local meteorological parameters, air duct parameters and equipment parameters; the local meteorological parameters include temperature and humidity, and the average value of the monthly average meteorological parameters of the hottest month at 14:00 in the past years or in the data-searchable years is taken.

[0053] Step 4: Calculate the actual total air quantity V 总 :

[0054]

[0055] Wherein, V 总 is the actual total air quantity, m 3 / h; t0 is the air inlet temperature of the air blower, ℃; p0 is the local atmospheric pressure, Pa; P1 is the total air system resistance before the air blower, Pa; V k,1 is the total air quantity in standard state, Nm 3 / h;

[0056] Step 5: Determine the selected air quantity and the selected pressure head of the air blower, which is specifically as follows:

[0057] 1) Selected air quantity V 选型 = 1.1 x k x V 总 / N

[0058] Wherein, V 选型 is the selected air quantity of the air blower, m 3 / h; k is the flow coefficient considering the air leakage at the air blower side after the air preheater is operated for one year, and if the accurate data of the equipment factory is absent, k is taken as 1.03; V 总 is the actual total air quantity, m 3h; N is the number of air supply fans;

[0059] 2) Selecting the pressure head P 选型 = 1.2 x (P1+P2+p lt )

[0060] Wherein, P1 is the total resistance of the air system before the air supply fan, Pa; P2 is the total resistance of the air system after the air supply fan, Pa; p lt is the furnace negative pressure (negative value), Pa. The furnace negative pressure p lt may be -30 Pa.

[0061] In some example embodiments, a non-transitory computer readable storage medium, such as a memory including instructions executable by a processor to perform the method described above is also provided. The non-transitory computer readable storage medium can be a Read Only Memory (ROM), a Random Access Memory (RAM), a magnetic tape and an optical storage device, etc.

[0062] Those skilled in the art can realize that the units and algorithm steps of the examples described in combination with the embodiments disclosed herein can be realized in electronic hardware or in combination of computer software and electronic hardware. Whether the functions are realized in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to realize the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application. Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described system, device and unit can refer to the corresponding processes in the foregoing method embodiments, which will not be described here.

[0063] In the embodiments disclosed herein, it should be understood that the disclosed method, product (including but not limited to device, equipment, etc.) can be implemented in other ways. For example, the device embodiments described above are merely illustrative, for example, the division of the units is merely a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some interface, device or unit, and can be electrical, mechanical or other forms. The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, that is, they can be located in one place, or can be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the embodiments. In addition, the functional units in each embodiment of the present application can be integrated in one processing unit, or each unit can be physically present, or two or more units can be integrated in one unit.

[0064] It should be understood that the flow and block diagrams in the drawings show the possible implementation architecture, function and operation of the system, method and computer program product according to the embodiments of the present application. In this regard, each block in the flow or block diagram can represent a module, program segment or part of code containing one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions noted in the blocks can occur in different order than that shown in the drawings. For example, two consecutive blocks can actually be executed substantially in parallel, and sometimes they can be executed in reverse order, depending on the function involved. It should also be noted that each block in the block diagram and / or flow diagram, and the combination of blocks in the block diagram and / or flow diagram, can be implemented by a dedicated hardware-based system for performing the specified function or action, or can be implemented by a combination of dedicated hardware and computer instructions. The present application is not limited to the flow and structure described above and shown in the drawings, and various modifications and changes can be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A simplified selection method for blowers in blast furnace gas boilers, characterized in that, The method includes the following steps: Calculate the amount of air required for combustion of each cubic meter of blast furnace gas based on the dry basis calorific value of the blast furnace gas; Calculate the standard state total air volume based on the blast furnace gas flow rate. Calculate the total resistance of the air system before the blower and the total resistance of the air system after the blower based on the standard total air volume, local meteorological parameters, duct parameters, and equipment parameters. The actual total air volume is calculated based on the local atmospheric pressure and the air temperature at the inlet of the blower. The selected air volume of the blower is calculated based on the actual total air volume, and the selected pressure head is calculated based on the total resistance of the air system before the blower, the total resistance of the air system after the blower, and the negative pressure in the furnace. The specific steps of the method are as follows: Step 1: Based on the calorific value Q of the blast furnace gas d Calculate the air volume V required for combustion of one cubic meter of blast furnace gas. k,0 : V k,0 =(1+1.61d k )(aQ d +b) Among them, V k,0 The amount of air required for combustion of one cubic meter of blast furnace gas, Nm 3 / Nm 3 Q d The dry basis calorific value of blast furnace gas is kJ / Nm³. 3 ;d k ρ represents absolute humidity of air, in kg / kg; a and b are calculation coefficients, where a = 2.09 × 10⁻⁶. -4 ~2.13×10 -4 b = 0.09–0.12; Step 2: Calculate the standard total air volume V based on the blast furnace gas flow rate B. k,1 : V k,1 =BV k,0 Among them, V k,1 The standard total air volume is expressed in Nm³. 3 / h; B is the dry standard flow rate of blast furnace gas entering the furnace, Nm³. 3 / h;V k,0 The amount of air required for combustion of one cubic meter of blast furnace gas, Nm 3 / Nm 3 ; Step 3: Calculate the total resistance P1 of the air system before the blower and the total resistance P2 of the air system after the blower based on the standard total air volume, local meteorological parameters, duct parameters, and equipment parameters; Step 4: Calculate the actual total air volume V based on the local atmospheric pressure p0 and the air temperature t0 at the blower inlet. 总 : Among them, V 总 The actual total air volume, in m 3 / h; t0 is the inlet atmospheric temperature of the blower, °C; p0 is the local atmospheric pressure, Pa; P1 is the total resistance of the air system before the blower, Pa; V k,1 The standard total air volume is expressed in Nm³. 3 / h; Step 5: Determine the required air volume and pressure head for the blower, as detailed below: 1) Selecting the air volume V 选型 =1.1×k×V 总 / N Among them, V 选型 For selecting the air volume of the blower, m 3 / h; k is the flow coefficient considering air leakage on the supply side after one year of operation of the air preheater; V 总 The actual total air volume, in m 3 / h; N is the number of blowers; 2) Selecting the pressure head P 选型 =1.2×(P1+P2+p lt ) Where P1 is the total resistance of the air system before the blower, Pa; P2 is the total resistance of the air system after the blower, Pa; p lt The furnace negative pressure is measured in Pa.

2. The simplified selection method for blast furnace gas boiler blowers as described in claim 1, characterized in that, The calorific value Q of the blast furnace gas d The data for the blast furnace gas flow rate B corresponds to the boiler BMCR operating condition.

3. The simplified selection method for blast furnace gas boiler blowers as described in claim 1, characterized in that, The local meteorological parameters include temperature and humidity; the average of the monthly average meteorological parameters at 2 PM in the hottest month of any year in the local area or the year for which data is available is taken.

4. The simplified selection method for blast furnace gas boiler blowers as described in claim 1, characterized in that, The furnace negative pressure p lt The value ranges from -20 to -50 Pa.

5. The simplified selection method for blast furnace gas boiler blowers as described in claim 1, characterized in that, In step 5, the surplus coefficient k for considering air leakage on the supply side after one year of operation of the air preheater is set to 1.03.

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