Experimental research on high-temperature corrosion of 650MWE opposed-firing boiler by near-wall air co-combustion adjustment

Low NOx staged combustion technology generates large amounts of CO gas in the primary combustion zone of the boiler, thereby exacerbating high-temperature corrosion in the boiler waterwall. Applying near-wall air (NWA) technology has proven to be an effective strategy for mitigating the reducing atmosphere near the waterwall. This study presents experimental configurations of NWA co-combustion adjustments conducted on a 650 MWe swirl-opposed boiler. The research investigates the impact of the flow rate of the outer secondary air of the burner and the flow rate of overfire air (OFA) on CO concentration near the sidewall. Results indicate that increasing the opening of the outer secondary air near the sidewall and reducing the opening of the OFA effectively reduced CO concentration.