Integrated Gas and Solid Model to Determine the Flow Performance in the SCR Reactor

In order to resolve the problem of the catalyst deactivation caused by fly ash in selective catalytic reduction (SCR) denitration systems, this work proposes a deflector at the economizer outlet and an ash blocking device at the ash hopper outlet. New integrated models are developed to analyze the gas and solid flow field in a SCR reactor. The particle image velocimetry (PINT) experiment is used to validate the models. It is found that the flow field distribution and velocity variation trend calculated by different integrated models are basically consistent and are in good agreement with PINT test results. The G&T-collision-deposition model has better applicability in calculating the fly ash deposition rate. The influence of different internals on flow field and fly ash distribution is also compared. It is found that the H-shaped square steel has the worst rectification effect, which would aggravate the abrasion of fly ash on the catalyst and equipment. The curved deflectors effectively improve the distribution of fly ash and show the best rectification effect.

Automated summary

This work proposes solutions to resolve catalyst deactivation caused by fly ash in SCR denitration systems using a deflector at the economizer outlet and an ash blocking device at the ash hopper outlet. New integrated models are developed to analyze the gas and solid flow field in a SCR reactor, and have been validated by particle image velocimetry experiment. The study finds that the use of curved deflectors effectively improves the distribution of fly ash and shows the best rectification effect.