Boiler room nitrogen oxide online detector

1、 Equipment Overview

Boiler room nitrogen oxide online detectoryesElectrochemical sensorContinuous monitoring equipment for technology, capable of real-time analysis of emissions during boiler combustion processesNOTheNO₂andNOxConcentration. The equipment adopts extraction sampling+Full process heat tracing pretreatment system, suitable for various types of boilers such as coal-fired, gas-fired, and oil fired, with a measurement range covering0-500mg/m³(Can be extended to2000mg/m³）The accuracy level has reached0.5Level, data collection frequency1time/In seconds, it meets the technical requirements and detection methods of the continuous monitoring system for fixed pollution source flue gas emissions（HJ 76-2017）Standard requirements.

2、 Main technical parameters

1. measurement parameters

oNO：0-500/2000 mg/m³(Optional), detection limit≤1 mg/m³, indication error±2%FS

oNO₂：0-500/2000 mg/m³(Optional), detection limit≤1 mg/m³, indication error±2%FS

oNOx：0-1000/4000 mg/m³(Automatic calculation), repeatability≤1%

oSmoke parameters: temperature（0-300℃，±1℃）Pressure（-20kPa~+20kPa，±0.5%FS）Flow rate（5-30m/s，±5%FS）

2. system performance

oResponse time:T90≤20second

oZero drift:≤±1%FS/24h

oSpan drift:≤±2%FS/24h

oData efficiency:≥95%

oHeat tracing temperature:120±5℃(Sampling pipeline)

oWork environment:-20℃~50℃(Analyzer), relative humidity≤95%(No condensation)

3、 System composition and functions

（1） Sampling preprocessing unit

1. Sampling probeStainless steel material, built-in ceramic filter element (aperture)≤2μm）Equipped with blowback function (compressed air pressure)0.4-0.6MPaThe blowback cycle can be set to prevent smoke and dust blockage.

2. Heat tracing pipelineDouble core polytetrafluoroethylene tube, fully electric heat tracing throughout the process (power)15W/m）Constant temperature control to avoidNO₂Dissolving in condensed water causes measurement deviation.

3. Preprocessing boxIntegrated cooler (temperature control)5±2℃）Peristaltic pump (automatic drainage), precision filter（0.45μm）Remove moisture and residual particulate matter from the flue gas, and output clean sample gas to the analyzer.

（2） Analysis and detection unit

1. analyzer：Electrochemical sensors,Built in temperature compensation algorithm.

2. calibration device: Supports automatic/Manual calibration, built-in standard gas interface（1/4'NPT）Can perform zero point calibration (high-purity nitrogen) and span calibration（NO/NO₂Standard mixture).

（3） Data acquisition and transmission unit

1. data acquisition instrument: Industrial gradePLCcontroller8Road analog input（4-20mA），2Road switch output (for alarm), supportsModbus RTU/485agreement.

2. Software featuresReal time data display (concentration, temperature, pressure, flow rate, etc.), historical data storage（≥6Month by month, minute by minute average), over limit alarm (sound and light)+Relay output, data export（ExcelFormat), remote communication（4G/NB-IoTIntegrate with environmental protection platforms.

4、 Installation and commissioning requirements

1. Installation locationThe sampling probe should be installed upstream of the vertical or horizontal section of the boiler flue, at a distance from disturbed components such as elbows and valves≥3Multiple flue diameter, sampling point flue gas velocity≥5m/s.

2. electrical connection: AnalyzerAC220V±10%Power supply, grounding resistance≤4ΩThe sampling preprocessing unit needs independent air switch protection（≥10A）.

3. Debugging steps：

oSystem airtightness test: Close the air inlet of the analyzer and apply0.2MPaPressure, holding pressure30Minute pressure drop≤5%.

oCalibration process: First, introduce zero point gas (nitrogen) to stabilize30Minutes, set zero point; Then introduce span air (such as200mg/m³ NO）Adjust the span coefficient to ensure that the measurement error is within the allowable range.

oData comparison: synchronized monitoring with portable flue gas analyzer, corresponding to the relative error≤±5%.

5、 Daily maintenance and troubleshooting

（1） Regular maintenance

1. Daily checkCheck the running status light of the analyzer (normally green), data curve trend, heat tracing temperature, and drainage status of the pre-treatment box.

2. weekly maintenanceClean the sampling probe filter (or replace, recommended lifespan)3Check the heat tracing pipeline for damage and calibrate the zero point every month.

3. Monthly maintenanceReplace the filter element and peristaltic pump tube of the pre-treatment box, perform span calibration, and check the pressure of the blowback system.

（2） Common fault handling

1. Data abnormally lowCheck if the sampling probe is blocked (clean the filter element or blow back), and if the heat tracing temperature meets the standard (if below)110℃Need to inspect the heat tracing pipeline.

2. Excessive driftConfirm whether the calibration gas has expired, whether the optical lenses are contaminated (wipe with anhydrous ethanol), and whether the ambient temperature has changed dramatically (install air conditioning or insulation measures).

3. Communication interruption: Check4GModule signal strength, data acquisition instrumentIPWhether the configuration is correct and whether the interface protocol of the environmental protection platform matches.

6、 Execution standards and compliance

This system meets the following standard requirements:

·HJ 76-2017Technical Requirements and Testing Methods for Continuous Monitoring System of Flue Gas Emissions from Fixed Pollution Sources

·HJ 128-2020Determination of Low Concentration Particulate Matter in Fixed Source Waste Gas by Weight Method

·GB 13271-2014Boiler Air Pollutant Emission Standards (Nitrogen Oxide Emission Limits)

·China Environmental Protection Product Certification（CCEP）Technical requirements

7、 Selection suggestions

1. Coal fired boilerRecommend using the high-end version (reinforced sampling probe)+Dual stage filtration pretreatment), suitable for high smoke and high humidity conditions.

2. gas boilerBasic version (simplified preprocessing) can be selected to reduce costs and meet the needs of low pollutant concentration monitoring.

3. Multiple boilers sharedConfigure a multi-path switching valve (maximum)8Implementing a single analyzer to monitor multiple emission outlets, saving investment.

(Note:Boiler room nitrogen oxide online detectorThe specific configuration needs to be customized according to the boiler tonnage, fuel type, and local environmental requirements