Influence on Outage Unit Flue Gas Flow CEMS by Flue Gas of Running Unit

Abstract

Unit 1 and unit 3 of a coal-fired power plant share a chimney. When unit 1 is outage and unit 3 is running, the chimney inlet flue gas flow CEMS of unit 1 is affected by flue gas of unit 3 and the CEMS displays abnormal during unit 1 outage. The flue gas flow test has been carried out and the reason has been analyzed. The results show that a small amount of flue gas from unit 3 is channeling into the stack inlet duct of unit 1, which leading to flue gas disturbance and producing dynamic pressure. The dynamic pressure is from 0 to 2 Pa. Based on the pitot tube speed measuring principle, the small dynamic pressure can lead to larger value of flue gas flow.