DIASYS netmation

Prediction System of Denitrification

Overview

A proprietary denitrification device from MHPS which uses ammonia as a reducing agent is used in thermal power plants. Nitric monoxide (NO) and NH3 react and decompose to nontoxic nitrogen (N2)and water(H2O).
This denitrification device requires highly efficient control over denitrification to eliminate unreacted NH3 in consideration of environment and costs.

A prediction system for denitrification from MHPS combines a proprietary prediction/control method for denitrification and a quick-response zirconia-based NOx (nitrogen oxide) meter to offer optimal control over NH3 supply when the load, NOx concentration, and other conditions fluctuate.

Features

  • Quick-response zirconia-based NOx meter
    The 90 percent response time of the conventional CLD type NOx meter is about 60 seconds, In the case of the zirconia-based NOx meter, it is about 14 seconds.

Response Time between Zirconia type and CLD

Response Time between Zirconia type and CLD

Appearance of Prediction System of Denification

Appearance of Prediction
System of Denitrification

  • Model based predictive control
    The system has a dynamic model for the denitrification reactor. It simulates the behavior of the denitrification reactor (controlled object), predicts the controlled variable (output of the controlled object), and determines the control input based on the predicted value.
    • Improving the steady-state characteristics
      Even if the characteristics of the denitrification device change, the steady-state characteristics can be maintained.
    • Improving the transient characteristics
      Predictive injection of NH3 improves the transient characteristics.

Nox-NH3 Sensor of Zirconia type

Measurement example

Example of basic measurement using a NOx sensor

Example of basic measurement using a NOx sensor

Operating principle

Theory of operation of a NOx sensor

Theory of operation of a NOx sensor

NH3共存下のNOx及び、NH3の測定原理

Theory of measurement of NH3, and that of NOx coexistent with NH3

System Configuration

System structure of the denitrification prediction system

System structure of the denitrification prediction system

Characteristics

The result of the response comparison test between the zirconia-based NOx sensor and the CLD type NOx sensor is as follows. Compared to the CLD type, response time has been successfully improved by about one minute.

The result of the response comparison test between the zirconia-based NOx sensor and the CLD type NOx sensor

The result of the response comparison test between the zirconia-based NOx sensor and the CLD type NOx sensor

Related Products

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http://www.mhps.com/en/products/category/diasys.html

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