A burner air-fuel ratio budget debugging method

Abstract

The present invention proposes a burner air-fuel ratio budget debugging method, which includes: collecting flue parameters, calculating the flue gas resistance h according to a preset formula m ; Collect boiler parameters; Collect excess air coefficient α; Convert boiler atmospheric pollutant emission concentration C; Collect natural gas parameters; Collect burner parameters; Calculate the air-fuel ratio under the preset load, and configure the air-fuel ratio to the burner. The beneficial effects of the present invention: The air-fuel ratio can be estimated, avoiding the problem of blind adjustment taking too long without a budget, improving debugging efficiency and reducing debugging costs.

Description

Technical Field

[0001] The invention relates to the field of burners, and in particular to an air-fuel ratio budget debugging method for burners. Background Art

[0002] The existing burner debugging methods are basically blind debugging. During the initial debugging, the ignition position is tried little by little, and the gas valve opening, air door valve opening and fan frequency are fumbling. The debugging often takes a long time and the debugging efficiency is low. At the same time, during the debugging, the natural gas valve opening and air door valve opening at the ignition position are not accurately grasped, and a large amount of CO will be generated at the moment of ignition. Its concentration can reach 100,000 ppm in a short time, which poses a risk of explosion. Summary of the invention

[0003] The present invention provides a burner air-fuel ratio budget debugging method, which solves the above-mentioned problems in the prior art.

[0004] The technical solution of the present invention is achieved in this way:

[0005] A burner air-fuel ratio budget debugging method, comprising:

[0006] Collect flue parameters and calculate the flue gas resistance h according to the preset formula m ;

[0007] Collect boiler parameters;

[0008] Collect excess air coefficient α;

[0009] Convert boiler air pollutant emission concentration C;

[0010] Collect natural gas parameters;

[0011] Collect burner parameters;

[0012] Calculate the air-fuel ratio under the preset load and assign the air-fuel ratio to the burner.

[0013] Further, calculate the smoke resistance h m The default formula is:

[0014]

[0015]

[0016] Where: λ is the friction coefficient, brick flue λ=0.05;

[0017] L is the length of the calculation segment, in meters;

[0018] d is the hydraulic diameter, in m;

[0019] ht is the velocity head at flue gas temperature t, i.e., dynamic pressure head, in mmH2O;

[0020] w0 is the average flow velocity of the delay under standard conditions, in Nm / s;

[0021] γ0 is the density of flue gas under standard conditions, in kg / Nm 3 ;

[0022] β is the volume expansion coefficient, which is equal to 1 / 273;

[0023] t is the actual temperature of the flue gas, in °C.

[0024] Furthermore, the calculation formula of the hydraulic diameter is:

[0025]

[0026] Where: F is the channel cross-sectional area, unit is m2;

[0027] U is the circumference of the channel section, in meters.

[0028] Preferably, the boiler parameters include boiler back pressure, boiler tonnage and furnace size.

[0029] Furthermore, the formula for calculating the boiler air pollutant emission concentration C is:

[0030]

[0031] Where: C is the converted boiler air pollutant emission concentration, in mg / m 3 ;

[0032] C' is the converted measured boiler air pollutant emission concentration, in mg / m 3 ;

[0033] φ(O2) is the baseline oxygen content;

[0034] φ'(O2) is the measured oxygen content.

[0035] Preferably, the natural gas parameters include natural gas pressure and natural gas calorific value.

[0036] Further, the steps of calculating the air-fuel ratio under a preset load and configuring the air-fuel ratio to the burner include:

[0037] Determine the specific values ​​of each link of combustion;

[0038] Estimate the amount of air and gas under different loads;

[0039] Get the air-fuel ratio required for debugging, and configure the air-fuel ratio to the combustion manager of the burner;

[0040] The burner debugging is completed through actual combustion fine-tuning.

[0041] The beneficial effects of the present invention are:

[0042] The burner air-fuel ratio budget debugging method described in the present invention can budget the air-fuel ratio, avoid the problem of blind debugging taking too long without a budget, improve the debugging efficiency, and reduce the debugging cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0044] Figure 1 The present invention is a flowchart of the steps of a burner air-fuel ratio budget debugging method. DETAILED DESCRIPTION

[0045] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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.

[0046] like Figure 1 As shown, a burner air-fuel ratio budget debugging method according to the present invention comprises:

[0047] Collect flue parameters and calculate the flue gas resistance h according to the preset formula m ;

[0048] Collect boiler parameters;

[0049] Collect excess air coefficient α;

[0050] Convert boiler air pollutant emission concentration C;

[0051] Collect natural gas parameters;

[0052] Collect burner parameters;

[0053] Calculate the air-fuel ratio under the preset load and assign the air-fuel ratio to the burner.

[0054] Specifically, the flue parameters mainly include flue resistance, flue distance, flue size and chimney height. The flue resistance mainly includes the resistance loss caused by the viscosity of the flue gas and the flue wall and the flue gas itself. The mixed gas produced by the combustion of the burner needs to be discharged through the flue, so the relevant parameters of the flue have a greater impact on the burner commissioning; the excess air coefficient α refers to the ratio of the actual amount of air supplied to the combustion of the fuel to the theoretical amount of air. The excess air coefficient α is determined by the fuel properties and the combustion method. When α<1, the fuel and the oxygen in the air are not completely burned, and a rich mixture is produced. Among them, α=0.4 is called the upper limit of flame propagation, and the mixture is too rich to burn; α=1 is called the theoretical mixture; α>1 is a lean mixture, among which, when α=1.4, it is called the lower limit of flame propagation, and the mixture is too lean to burn; the excess air coefficient α not only affects combustion, but also affects emissions. If the excess air coefficient α is too low, the carbon monoxide (CO) concentration is high, and if the excess air coefficient α is too high, it is very easy to produce NO X , causing NO X Emissions exceed standards.

[0055] Among them, calculate the smoke resistance h m The default formula is:

[0056]

[0057]

[0058] Where: λ is the friction coefficient, brick flue λ=0.05;

[0059] L is the length of the calculation segment, in meters;

[0060] d is the hydraulic diameter, in m;

[0061] h t is the velocity head at flue gas temperature t, i.e., dynamic pressure head, in mmH2O;

[0062] w0 is the average flow velocity of the delay under standard conditions, in Nm / s;

[0063] γ0 is the density of flue gas under standard conditions, in kg / Nm 3 ;

[0064] β is the volume expansion coefficient, which is equal to 1 / 273;

[0065] t is the actual temperature of the flue gas, in °C.

[0066] The calculation formula of hydraulic diameter is:

[0067]

[0068] Where: F is the channel cross-sectional area, unit is m2;

[0069] U is the circumference of the channel section, in meters.

[0070] Among them, preferably, the boiler parameters include boiler back pressure, boiler tonnage and furnace size.

[0071] Specifically, boiler back pressure refers to the pressure in the combustion chamber on the boiler furnace side. Natural gas hot water boilers are micro-positive pressure boilers. Therefore, the boiler back pressure of natural gas hot water boilers is the resistance to the flow of flue gas from the furnace to the exhaust port. Tests have shown that this value affects the flow of flue gas and is related to the burner parameters. The function of the furnace is to ensure that the fuel is burned as much as possible. It should have a reasonable shape and size to facilitate cooperation with the burner, organize the aerodynamic field in the furnace, prevent the flame from sticking to the wall, not hitting the wall, have a high degree of filling, and have uniform wall heat load.

[0072] The formula for calculating the boiler air pollutant emission concentration C is:

[0073]

[0074] Where: C is the converted boiler air pollutant emission concentration, in mg / m 3 ;

[0075] C' is the converted measured boiler air pollutant emission concentration, in mg / m 3 ;

[0076] φ(O2) is the baseline oxygen content;

[0077] φ'(O2) is the measured oxygen content.

[0078] Wherein, preferably, the natural gas parameters include natural gas pressure and natural gas calorific value.

[0079] Specifically, the size of the natural gas pressure affects the amount of gas injected into the furnace, and different burners have different requirements for the pressure of natural gas; the calorific value of natural gas is used as an auxiliary calculation.

[0080] The steps of calculating the air-fuel ratio under a preset load and configuring the air-fuel ratio to the burner include:

[0081] Determine the specific values ​​of each link of combustion;

[0082] Estimate the amount of air and gas under different loads;

[0083] Get the air-fuel ratio required for debugging, and configure the air-fuel ratio to the combustion manager of the burner;

[0084] The burner debugging is completed through actual combustion fine-tuning.

[0085] Specifically, the specific values ​​of each link of the combustion are determined mainly through flue parameters, boiler parameters, excess air coefficient α, atmospheric pollutant emission concentration C, natural gas parameters and burner parameters, and the air and gas volumes under different loads are estimated, ultimately obtaining the air-fuel ratio required for debugging. The air-fuel ratio is then configured to the burner's combustion manager and fine-tuned through actual combustion to complete the entire debugging process.

[0086] The burner air-fuel ratio budget debugging method of the present invention is used to debug the boiler, which has high debugging efficiency and can meet the following standards in a short time:

[0087] Table 1 Emission concentration limits of air pollutants from newly built boilers

[0088] Pollutant Project Emission concentration limit <![CDATA[Particulate matter (mg / m 3 )]]> 5 <![CDATA[Sulfur dioxide (mg / m 3 )]]> 10 <![CDATA[Nitrogen oxides (mg / m 3 )]]> 30 <![CDATA[Mercury and its compounds (μg / m 3 )]]> 0.5 Smoke blackness (Lingelmann, level) Level 1

[0089] Table 2 Emission concentration limits of air pollutants from in-use boilers

[0090] Pollutant Project Emission concentration limit <![CDATA[Particulate matter (mg / m 3 )]]> 5 <![CDATA[Sulfur dioxide (mg / m 3 )]]> 10 <![CDATA[Nitrogen oxides (mg / m 3 )]]> 80 <![CDATA[Mercury and its compounds (μg / m 3 )]]> 0.5 Smoke blackness (Lingelmann, level) Level 1

[0091] The burner air-fuel ratio budget debugging method described in the present invention can budget the air-fuel ratio, avoid the problem of blind debugging taking too long without a budget, improve the debugging efficiency, and reduce the debugging cost.

[0092] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A burner air-fuel ratio budget debugging method, characterized in that: include: Collect flue parameters and calculate the flue gas resistance h according to the preset formula m ; Collect boiler parameters, including boiler back pressure, boiler tonnage and furnace size; collect excess air coefficient α; Convert boiler air pollutant emission concentration C; Collect natural gas parameters, including natural gas pressure and natural gas calorific value; collect burner parameters; Calculate the air-fuel ratio under the preset load and assign the air-fuel ratio to the burner; Among them, calculate the smoke resistance h m The default formula is: Where: λ is the friction coefficient, brick flue λ=0.05; L is the length of the calculation segment, in meters; d is the hydraulic diameter, in m; h t is the velocity head at flue gas temperature t, i.e., dynamic pressure head, in mmH2O; w0 is the average flow velocity of the delay under standard conditions, in Nm / s; γ0 is the density of flue gas under standard conditions, in kg / Nm 3 ; β is the volume expansion coefficient, which is equal to 1 / 273; t is the actual temperature of the flue gas, in °C; The calculation formula of hydraulic diameter is: Where: F is the channel cross-sectional area, unit is m2; u is the circumference of the channel section, in m; The formula for calculating the boiler air pollutant emission concentration C is: Where: C is the converted boiler air pollutant emission concentration, in mg / m 3 ; C' is the converted measured boiler air pollutant emission concentration, in mg / m 3 ; φ(O2) is the baseline oxygen content; φ'(O2) is the measured oxygen content.

2. The burner air-fuel ratio budget debugging method according to claim 1 is characterized in that: The steps of calculating the air-fuel ratio at a preset load and assigning the air-fuel ratio to the burner include: Determine the specific values ​​of each link of combustion; Estimate the amount of air and gas under different loads; Get the air-fuel ratio required for debugging, and configure the air-fuel ratio to the combustion manager of the burner; The burner debugging is completed through actual combustion fine-tuning.

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