Effect of Heat Recovery from Flue Gas on the Local Humidity and NOx Dispersion in a Thermal Power Station

• Published in: Aerosol and Air Quality Research 2014, Vol.14 (3), p.840-849
• Main Authors: Wu, Shi Chang, Jo, Young Min, Park, Young Koo
• Format: Article
• Language: English
• ISSN: 1680-8584; 2071-1409
• DOI: 10.4209/aaqr.2013.01.0028

The flue gas dispersion from the stack of a power station was investigated prior to addition of a high efficiency heat recovery facility. Decrease of the flue gas temperature from 115°C to 40°C by heat recovery could influence the local humidity and thermal NO x level. It might also result in the formation of a white large plume due to the early saturation of vapor around the stack, and deteriorate dispersion of thermal NO x . Numerical simulation revealed that the area influenced by flue gas has been enlarged, particularly in winter. The volume of visible plume indicating RH 1.0 increased to 120 m high and 80 m wide for the flue gas at 40°C, while a smaller plume was formed that was 85 m high and 50 m wide for that at 115°C. The humid air of the flue gas extended nearly 160 m further along the ground. The distance for the maximum NO 2 concentration on the ground increased by 80 m and 50 m for 1 m/s wind and 3 m/s, respectively. The area influenced at the ground level expanded more than 250 m at 1 m/s wind after heat recovery. In particular, lowering the temperature of flue gas may affect the local environment more significantly in unusual cases including temperature inversions.