플랜트 저널 (Plant Journal)
- 제11권2호
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- Pages.32-38
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- 2015
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- 1976-8702(pISSN)
암모니아 추가 주입에 의한 배열회수보일러 급수의 수소이온농도 조절
pH Control of Feed Water for HRSG with Additional Injection of NH3
- Mok, Yong-kang (Doosan Heavy Industries & Construction Co., Inc.) ;
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Moon, Seung-Jae
(School of Mechanical Engineering, Hanyang University) ;
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Lee, Jae-Heon
(School of Mechanical Engineering, Hanyang University)
- 투고 : 2015.04.29
- 발행 : 2015.06.30
초록
탈기기-저압드럼 일체형 배열회수보일러로 구성된 복합화력발전소에서 발생한 저압증기발생기의 튜브파손 사례를 관찰하였다. 수소이온농도 변화를 관찰한 결과 복수펌프 후단에 주입된 암모니아가 탈기기를 통과한 후 저압 드럼 내에서 암모니아 분배율에 따라 증기와 함께 다량의 암모니아가 소모되어 급수 내 수소이온농도 저하를 확인하였다. 이를 해결하기 위해 저압드럼 내에 암모니아를 직접 주입할 수 있도록 추가 주입위치를 선정하였으며 적정량의 암모니아 용액을 주입함으로써 보일러 급수의 최적 수소이온농도인 9.2~9.6 으로 조절이 가능하다는 결론을 얻었다.
This study was conducted on combined cycle power plant consisting of HRSG with integral deaerator type to avoid tube failures of low pressure evaporator tubes. Based on the observation of pH variation at the discharge of boiler feed water pump by continuous pH measurement for a period of time, it was identified that pH of feed water is getting reduced as ammonia is distributed into vapor and liquid depending on the distribution ratio of ammonia in the LP drum after the deaerator. To solve this problem, the counterplan was prepared by reexamination of ammonia injection point and quantity. In conclusion, it was accomplished that 9.2~9.6 is the optimized pH range for boiler feed water by arranging additional piping for ammonia to inject directly to LP drum.