Keys to better AIG tuning and permanent sampling grid
Steve Houghton focused on tuning of ammonia injection grids (AIG) and the value of installing a permanent sampling grid before diving into related case histories that included financial benefits.
A clean AIG is important to optimal tuning, he said. Verify that valves are in working order and that flow gages on the valves are functioning. Having a permanent sampling grid solves the issue of blocked sampling ports and allows for a complete traverse measurement. Additional benefits: Sample without need for a manlift or scaffolding; tune the AIG faster and more precisely. Break even on the installed cost after two or three uses.
Case study 1: An AIG/SCR replacement project for a G-class combined cycle reduced ammonia consumption by 10% and cut ammonia slip in half (Fig 6). Case study 2: At an F-class combined cycle, Groome reduced ammonia consumption by 26% and reduced ammonia slip to 25% of the permit limit, saving $44,000 annually.