HJ 692-2014Stationary source emission. Determination of nitrogen oxides. Non-dispersive infrared absorption method (English PDF)

Foreword

To implement the "People's Republic of China Environmental Protection Law" and "People's Republic of China Air Pollution Prevention Law," guard ring Environment, protect people's health, specifications fixed monitoring methods source emission of nitrogen oxides, the development of this standard.

This standard specifies the determination of stationary sources of nitrogen oxides in the exhaust gas Central Africa dispersive infrared absorption method.

This standard is the first release.

This standard is developed by the Ministry of Environmental Protection Science, Technology organization.

This standard drafting units. China National Environmental Monitoring Center, Shanghai Environmental Monitoring Center, Hebei Province Environmental Monitoring Center.

The standard verification unit. Environmental Monitoring Center Station of Hebei Province, Shenyang Environmental Monitoring Central Station, Hubei environmental monitoring Heart Station, Guiyang Municipal Environmental Monitoring Center, Tianjin Environmental Monitoring Center, Qinhuangdao City environmental protection monitoring station this standard MEP February 7, 2014 for approval.

This standard since April 15, 2014 implementation.

The standard explanation by the Ministry of Environmental Protection.

Determination of Non-Stationary source emission of nitrogen oxides dispersive infrared absorption method

1 Scope

This standard specifies the determination of stationary sources of nitrogen oxides in the exhaust gas Central Africa dispersive infrared absorption method.

This standard applies to the determination of stationary sources of nitrogen oxides in the exhaust gas.

This method of nitric oxide (as NO2) detection limit of 3mg/m3, measured lower limit of 12mg/m3.

2 Normative references

This standard refers to the contents of the following documents or the terms. For undated references, the effective version applies to this standard.

GB/T 16157 Stationary source emission-Determination of particulates and gaseous pollutants sampling methods HJ/T 75 stationary sources Continuous Emission Monitoring Technical Specification (Trial) HJ/T 76 stationary sources Continuous Emission Monitoring system technical requirements and test methods (Trial) HJ/T 373 stationary sources Monitoring Quality Assurance and Quality Control Technical Specifications HJ/T 397 stationary source emission monitoring and technical specifications

3 Terms and Definitions

4 Principle of the method

The use of NO gas infrared spectral regions, particularly selective 5.3µm wavelength of light absorbed by the Lambert - NO Beer law quantitative exhaust and NO2 in the exhaust gas through the converter for the reduction of the concentration of NO after.

5 and elimination of interference this method can eliminate the interference of interfering gases by tandem-type pneumatic detectors or gas filter correlation technique. Exhaust gas particulate matter and water vapor Interference, as well as the impact on the measured temperature of the exhaust gas through the filter dust, desiccant cooling means to cool the exhaust gas and the rapid addition of water to reduce or eliminate Interference to an acceptable level.

6 Reagents and materials

6.1 of nitric oxide, nitrogen dioxide standard gas Gas certified environmental standards, uncertainty of not more than 2% of the current uncertainty or attainable. Check the indication error and standard deviation system Quasi-gas concentration is 40% ~ 60% CS or equal to CS.

7 Instruments and equipment

9 Analysis step

10 Results Calculation and representation

11 Precision and accuracy

The precision and accuracy of measurement of NO NO2 concentrations are counted.

The precision of the method 11.1 Six laboratories in a power plant emissions of NO concentration were measured simultaneously. One of the units in the exhaust gas concentration of 588mg/m3 ~ 609mg/m3, average of 592mg/m3; another unit in the exhaust gas concentration 187mg/m3 ~ 201mg/m3, average of 195mg/m3.

Laboratory relative standard deviations were. 2.5% to 3.6%, 1.4% ~ 4.2%;

Interlaboratory relative standard deviations were. 1.4%, 2.4%;

Repeatability limit. 55mg/m3,17mg/m3;

Reproducibility limit. 7.4mg/m3,12mg/m3.

6 laboratory levels of 100mg/m3,396mg/NO standard gas m3,1.02 × 103mg/m3 were measured.

Laboratory relative standard deviations were. 0 to 1.0%, from 0 to 0.6%, from 0 to 0.4%;

Interlaboratory relative standard deviations were. 1.9%, 1.2%, 0.4%;

Repeatability limit. 2.1mg/m3,3.7mg/m3,5.1mg/m3;

Reproducibility limit. 4.9mg/m3,12mg/m3,9.6mg/m3.

Accuracy of the method 11.2 6 laboratory standard levels of NO gas 100mg/m3,396mg/m3,1019mg/m3 were measured.

Relative error. 0.3% to 3.4% - 0.8% to 2.0%, from 0.4% to 1.4%;

The final value of the relative error. 1.2% ± 2.7%, 0.4% ± 2.2%, 0.8% ± 0.7%.

12 Quality Assurance and Quality Control

12.1 Instruments and some auxiliary equipment such as a barometer, thermometer must be approved by the relevant units certified by metrological verification, and in the test validity Within limits.

12.2 instrument should be more than the ability to resist negative pressure flue negative pressure to prevent the instrument sampling flow is reduced, resulting in low or measurement results can not be measured.

The components of the instrument should be connected firmly 12.3, measured before and after the screening equipment shall be in accordance with the requirements of air tightness, can be blocking tight inlet, if the instrument Sample flow rate indication to zero in 2min, showed air-tightness.

Determination of zero gas and NO standard gas before the 12.4 measured according to the standard 9.2 step, the Department calculated indication error measurement and inspection equipment System deviation, if the indication error and/or system deviation does not comply with Article 7.1.2 (2) and (3) requirements should find out the reasons and make the appropriate repair dimension Protection, until only after the conduct of monitoring to meet the requirements.

Determination of the standard zero gas and NO gas was measured according to the standard after 12.5 9.2 step, the Department calculated indication error measurement and inspection equipment System deviation. If the indication error and systematic bias in line with Article 7.1.2 (2) and (3) requirements, determines whether the measurement results of this sample is valid; otherwise, the contractor the measurement results once the final version of the sample is invalid.

Zero drift 12.6 measured at least once a month before and after the span drift checks. Zero drift, span drift absolute value should be small to 3% CS (when calibrated span <=200µmol/mol, less than 5.0% CS). Otherwise, it is timely for instrument calibration and maintenance.

12.7 Determination completed before the shutdown, according to the requirements of the specification through the instrument into the ambient air or high purity nitrogen flushed clean instruments.

12.8 at least once every six months with a low (Appendix A (Informative) Measured before and after the performance of the instrument Checklist Laboratory name Location Determination Equipment manufacturing plant as the model, serial number principle of calibrated span (CS) (µmol/mol, mg/m3) gas flow rate (L/min) Ambient temperature (oC) ambient pressure (kPa) relative humidity (RH%) Standard gas production unit measured pollutant name Testers Determination Date The date

Table A-1 shows error

After the measurement before the standard gas measurement Name Concentration/A rated value/A i mean/A (avg) i Indication error /% ( A (avg) i - A )/A Found/A i mean/A (avg) i Indication error /% ( A (avg) i - A )/A NO

NOTE. To determine the value A i refers to standard gas measurement results in direct measurement mode is obtained

Table A-2 system deviation

After the measurement before the standard gas measurement Name concentration measurement value of the system deviation ( B (avg) - A (avg) )/C.S.

Measured value system deviation ( B (avg) - A (avg) )/C.S. A A (avg) B B (avg) A A (avg) B B (avg) Zero gas NO Note. A measured value of 1 means the standard gas measurement results in direct measurement mode; 2 measured values B refers to the measurement result in the system standard gas measurement mode.

Table A-3 zero drift and span drift

Standard gas

Date Time

Zero drift Span drift Zero drift absolutely zero reading error calibration Range delta Z C.S.

Standard gas

reading

Span drift

Absolute error

calibration

Range

delta S

Name Concentration

Starting

finally

deltaZ = Zi -Z0

Starting

finally

deltaS = Si -S0

NOTE. Starting expressed measured before, after the final determination indicates.

Table A-4 NO2 to NO conversion efficiency

Standard gas measurement results Name Concentration/A rated value/A i mean/A (avg) i conversion efficiency /% (A (avg) i/A) NO2

NOTE. To determine the value A i mean NO2 standard gas is converted to NO after the reduction, under the direct measurement mode to get the NO measurement results.