CN105160479A - Method for measuring boiler dry flue gas volume based on coal caloric values and exhaust fume oxygen amount - Google Patents

Abstract

The invention discloses a method for measuring boiler dry flue gas volume based on coal caloric values and exhaust fume oxygen amount. The exhaust fume oxygen amount can be acquired from the database of a power plant decentralized control system DCS, the coal caloric values are obtained from a power plant coal industrial analysis report, an excess air coefficient is obtained through the calculation based on the exhaust fume oxygen amount, and the CO2 theoretical maximum value is obtained through the calculation based on the coal caloric values. The content of CO2 in the dry flue gas is obtained through the calculation based on the excess air coefficient and the CO2 theoretical maximum value, and the volume and the mass of the dry flue gas are respectively obtained through the calculation based on the content of CO2 in the dry flue gas and the coal caloric values. The measuring method can effectively prevent the strict requirement that the coal component element analysis needs to be calculated based on national standard, simplifies the calculating model of the dry flue gas, and can meet the needs for the online calculation of the dry flue gas of a boiler.

Description

A kind of method measuring boiler dry flue gas amount based on coal-fired calorific value and oxygen content in exhaust gas

Technical field

The present invention relates to a kind of assay method of boiler dry flue gas amount, belong to soft-measuring technique field.

Background technology

Boiler dry flue gas amount, as parameter important in boiler combustion process, is directly connected to the discharge capacity of boiler economics and pollutant.At present, boiler dry flue gas amount normally calculates based on the master pattern in GB10184-88, namely determines exhaust gas volumn by the ultimate analysis of coal-fired composition.

But the dry flue gas amount computing method of national Specification are general only for boiler thermal output test or boiler performance certification test.Because power plant does not possess the ability of coal-fired component element analysis, therefore the computing method of the dry flue gas amount of national Specification can not be used for the operating analysis of power plant.

Summary of the invention

Goal of the invention: in order to overcome the deficiencies in the prior art, the invention provides a kind of method measuring boiler dry flue gas amount based on coal-fired calorific value and oxygen content in exhaust gas, can realize the dry flue gas amount of other measured operating parameter boilers by coal-fired calorific value and boiler.

Technical scheme: for achieving the above object, the technical solution used in the present invention is:

A kind of method measuring boiler dry flue gas amount based on coal-fired calorific value and oxygen content in exhaust gas, oxygen content in exhaust gas is obtained from the database of DCS of Power Plant DCS, the coal-fired calorific value of coal is obtained from power plant coal quality industrial analysis report, calculate excess air coefficient according to described oxygen content in exhaust gas, calculate CO according to described coal-fired calorific value ₂theoretical maximum; According to described excess air coefficient and CO ₂theoretical maximum calculates CO ₂content in dry flue gas, according to described CO ₂content in dry flue gas and coal-fired calorific value calculate volume and the quality of dry flue gas respectively.

Concrete calculation procedure is as follows:

Step 1: obtain oxygen content in exhaust gas O from the database of DCS of Power Plant DCS _2py, from power plant coal quality industrial analysis report, obtain the coal-fired calorific value Q of low level of coal _dy;

Step 2: the excess air coefficient α calculating fume side:

$\mathrm{\α}=\frac{21}{21-O_{2py}}$

Step 3: calculate CO ₂content in dry flue gas:

(1) CO is calculated ₂theoretical maximum CO _2max:

${\mathrm{CO}}_{2max}=\frac{(0.10162+0.04399\×Q_{dy}/1000)}{(0.44971+0.23825\×Q_{dy}/1000)}\×100\%$

(2) CO is calculated ₂content CO in dry flue gas ₂:

${\mathrm{CO}}_2=\frac{{\mathrm{CO}}_{2\max }}{\mathrm{\α}}\×100\%$

Step 4: the volume V calculating dry flue gas _lywith quality μ _ly:

(1) dry flue gas volume V is calculated _ly:

V _ly＝(1.1296-0.02028×Q _dy/1000)+(0.10162+0.04399×Q _dy/1000)/CO ₂

(2) dry flue gas quality μ is calculated _ly:

μ _ly＝(0.96569+0.00707×Q _dy/1000)+(0.13139+0.05699×Q _dy/1000)/CO ₂

Beneficial effect: the present invention is based on coal-fired calorific value and calculate dry flue gas amount, effectively prevent national standard and calculate the rigors needing coal-fired component element to analyze, simplify the computation model of dry flue gas amount, the needs in line computation of boiler dry flue gas amount can be met.

Accompanying drawing explanation

Fig. 1 is method flow diagram of the present invention.

Embodiment

Below in conjunction with accompanying drawing, the present invention is further described.

Be illustrated in figure 1, a kind of method measuring boiler dry flue gas amount based on coal-fired calorific value and oxygen content in exhaust gas, oxygen content in exhaust gas is obtained from the database of DCS of Power Plant DCS, the coal-fired calorific value of coal is obtained from power plant coal quality industrial analysis report, calculate excess air coefficient according to described oxygen content in exhaust gas, calculate CO according to described coal-fired calorific value ₂theoretical maximum; According to described excess air coefficient and CO ₂theoretical maximum calculates CO ₂content in dry flue gas, according to described CO ₂content in dry flue gas and coal-fired calorific value calculate volume and the quality of dry flue gas respectively.

The present invention, for 1000MW boiler, as follows to the detailed step of dry flue gas quantitative determination:

Step 1: obtain oxygen content in exhaust gas O from the database of DCS DCS of Power Plant DCS _2py, the operating condition down smoke-discharging oxygen amount value O in certain moment _2pyfor: 4.0%, from power plant coal quality industrial analysis report, obtain the coal-fired calorific value Q of low level of coal _dy, the coal-fired calorific value Q of low level of coal _dy: 20742.0kJ/kg;

Step 2: the excess air coefficient α calculating fume side:

$\mathrm{\α}=\frac{21}{21-O_{2py}}=1.2353$

Step 3: calculate CO ₂content in dry flue gas:

(1) CO is calculated according to the derivation of thermal engineering atlas curve ₂theoretical maximum CO _2maxformula:

${\mathrm{CO}}_{2max}=\frac{(0.10162+0.04399\×Q_{dy}/1000)}{(0.44971+0.23825\×Q_{dy}/1000)}\×100\%=18.81\%$

(2) CO is calculated ₂content CO in dry flue gas ₂%:

${\mathrm{CO}}_2=\frac{{\mathrm{CO}}_{2\max }}{\mathrm{\α}}k100\%=15.26\%$

Step 4: the volume V calculating dry flue gas _lywith quality μ _ly:

(1) dry flue gas volume V is calculated according to the derivation of thermal engineering atlas curve _lyformula:

V _ly＝(1.1296-0.02028×Q _dy/1000)+(0.10162+0.04399×Q _dy/1000)/CO ₂＝7.369m ³/kg

(2) dry flue gas quality μ is calculated according to the derivation of thermal engineering atlas curve _lyformula:

μ _ly＝(0.96569+0.00707×Q _dy/1000)+(0.13139+0.05699×Q _dy/1000)/CO ₂＝9.7389kg/kg

The above is only the preferred embodiment of the present invention; be noted that for those skilled in the art; under the premise without departing from the principles of the invention, can also make some improvements and modifications, these improvements and modifications also should be considered as protection scope of the present invention.

Claims (2)

1. one kind measures the method for boiler dry flue gas amount based on coal-fired calorific value and oxygen content in exhaust gas, it is characterized in that: from the database of DCS of Power Plant DCS, obtain oxygen content in exhaust gas, the coal-fired calorific value of coal is obtained from power plant coal quality industrial analysis report, calculate excess air coefficient according to described oxygen content in exhaust gas, calculate CO according to described coal-fired calorific value ₂theoretical maximum; According to described excess air coefficient and CO ₂theoretical maximum calculates CO ₂content in dry flue gas, according to described CO ₂content in dry flue gas and coal-fired calorific value calculate volume and the quality of dry flue gas respectively.

2. a kind of method measuring boiler dry flue gas amount based on coal-fired calorific value and oxygen content in exhaust gas according to claim 1, is characterized in that: concrete calculation procedure is as follows:

Step 1: obtain oxygen content in exhaust gas O from the database of DCS of Power Plant DCS _2py, from power plant coal quality industrial analysis report, obtain the coal-fired calorific value Q of low level of coal _dy;

Step 2: the excess air coefficient α calculating fume side:

$\mathrm{\α}=\frac{21}{21-O_{2py}}$

Step 3: calculate CO ₂content in dry flue gas:

(1) CO is calculated ₂theoretical maximum CO _2max:

${\mathrm{CO}}_{2max}=\frac{(0.10162+0.04399\×Q_{dy}/1000)}{(0.44971+0.23825\×Q_{dy}/1000)}\×100\%$

(2) CO is calculated ₂content CO in dry flue gas ₂:

Step 4: the volume V calculating dry flue gas _lywith quality μ _ly:

(1) dry flue gas volume V is calculated _ly:

V _ly＝(1.1296-0.02028×Q _dy/1000)+(0.10162+0.04399×Q _dy/1000)/CO ₂

(2) dry flue gas quality μ is calculated _ly:

μ _ly＝(0.96569+0.00707×Q _dy/1000)+(0.13139+0.05699×Q _dy/1000)/CO ₂