System Overview

The ZN-NHK3000 ammonia injection zone real-time optimization control system can adjust the corresponding ammonia injection amount in real-time by monitoring the concentration distribution of NOx at the inlet and outlet of the SCR device online. It is a control mode that accurately sprays ammonia into corresponding zones based on the distribution of NOx concentration in each zone. Real time optimization control of ammonia spraying zones is a significant technological upgrade to the optimization and adjustment of manual ammonia spraying zones.

The launch of the real-time optimization control system for spray zone will bring a new operating mode to the SCR denitrification device;
Accurate automatic control of ammonia injection volume to reduce costs for SCR system operation;
●Accurate automatic control of ammonia injection volumeMeet strict environmental emission standards;
●Accurate automatic control of ammonia injection volumeImprove the denitrification efficiency of SCR system;
●Accurate automatic control of ammonia injection volumeExtend the service life of catalysts;
●Accurate automatic control of ammonia injection volumeReduce ammonia escape and avoid corrosion and blockage of the air preheater.

Three key technologies for achieving real-time optimization control of ammonia spraying zones:

1. Online monitoring technology for atmosphere concentration distribution.
2. Remote electric control regulation technology for ammonia injection control valve zoning.
3. Artificial intelligence control software technology.

Online monitoring technology for atmosphere concentration distribution:

The ZN-NOx/02 nitrogen oxide analyzer, based on the principle of semiconductor ceramics, monitors the concentration of NOx and O2 horizontally at multiple points on the inlet and outlet smoke of the SCR device, achieving online monitoring of the concentration distribution of NOx in the smoke.
The ZN-NH1000 high-temperature extraction escape ammonia detector, which adopts the laser principle, conducts horizontal distribution multi-point inspection and monitoring of NH3 concentration on the outlet smoke of the SCR device, achieving online monitoring of NH3 concentration distribution at the SCR outlet.

Technical features

The monitoring of NOx adopts in-situ direct insertion NOx/O2 probes.

There are no excessively long sampling pipelines, no need for complex preprocessing systems, no need to directly insert samples into the flue, and the response is fast.

◆The NOx probe is equipped with dual sensors, which can simultaneously analyze NOx and O2.
◆The detection value of the NOx probe is the total value of NO and NO2, without the need for a NO2 converter.
◆The monitoring of NH3 is carried out using a full range 250 ° C high-temperature extraction laser analyzer.

◆A set of instruments with up to 6 sampling probes for distributed inspection of flue gas atmosphere.
◆All monitoring points are customized according to the width and depth of the flue to meet the needs of different units.

Remote electric control regulation technology for ammonia injection control valve zoning

Adopting intelligent electric regulating valves to achieve linear control of the flow rate of nitrogen and gas mixing nozzles. Based on the results of detecting the concentration distribution of the atmosphere, the automatic ammonia injection control model software calculates in real-time and outputs a flow valve control signal through closed-loop control. By using the PROFIBUS bus network and DCS system control mode, various flow control valves are driven to achieve automatic control of ammonia injection.

Artificial Intelligence Control Software Technology

Connect all detection signals and valve control signals to a dedicated computer control system. The control software installed in the system provides a reasonable ammonia injection zone control strategy based on real-time online monitoring of atmosphere concentration distribution data input, combined with SCR and boiler real-time operation data, using artificial intelligence control algorithms and self-learning systems. The ammonia injection amount is adjusted in real-time through the system execution mechanism.