발전소 실외 노출 고밀도폴리에틸렌(HDPE) 배관 결함 저감 방안에 관한 연구 = A Study on the Reduction of Defect of HDPE Piping Installed Outdoors in Power Plant

국문 초록 (Abstract)

발전소 해수전해설비는 해수와 접촉하는 설비에 어패류 등의 서식 및 침적을 방지하기 위해
해수를 전기분해 하여 얻은 차아염소산나트륨을 HDPE(High Density Polyethylene) 배관을
통해 공급하는 설비이다. HDPE 배관의 기대수명은 50년 정도이나 설치 후 사용기간이 15년을
넘지 않은 배관에서 빈번하게 손상이 발생되어 차아염소산나트륨 누설에 따른 정비 및 교체
작업 수행을 위하여 해수전해설비 운전을 정지해야 되는 문제가 발생한다.
본 연구에서는 야외에 설치되어 사용하는 HDPE 배관의 열화 정도를 실험을 통해 확인하였고,
금속 재질에 비해 상대적으로 열팽창 계수가 큰 HDPE 배관의 동/하절기 온도차에 따른 열압축/
팽창 시 지지대 설치 정도(U-bolt 간격, 체결 토크 값)에 따른 배관 등가응력 값을 분석하였다.
누설 발생에 따라 교체 후 철거된 배관과 동일 사이즈 신품 배관의 시편을 확보하여 강도 시험을
수행한 결과 파단점 항복강도와 신장률 값의 저하를 확인 할 수 있었는데 HDPE 배관 제작 시
첨가되는 자외선 안정제/차단제 효과로 단기간 자외선에 의한 열화 정도는 미미하지만 열화
환경에서 장기간 사용 시 산화반응 및 고분자 사슬 분해에 따른 자유라디컬 생성이 신장률 및
파단점 항복강도 저하의 원인일 것으로 사료된다[2,3].
본 연구 결과는 발전소 해수전해설비 차아염소산나트륨 공급 HDPE 배관의 건전성 향상을 위한
결함 저감 방안을 제시하는 데 활용하고자 한다.

목차 (Table of Contents)

• I. 서 론 ··································································································································································· 1
• 1.1 연구배경 ········································································································································ 1
• 1.2 선행연구 분석 ······························································································································ 2
• 1.3 연구목적 ········································································································································ 3
• II. 이론적 배경 ···················································································································································· 4
• 2.1 해수전해설비 ································································································································ 4
• 2.2 고밀도 폴리에틸렌(HDPE, High Density Polyethylene) ···················································· 5
• 2.3 고분자 산화반응 ·························································································································· 5
• 2.4 등가응력(Equivalent Stress or Von Mises Stress) ······························································· 6
• III. 강도시험 및 응력해석 방법 ················································································································· 6
• 3.1 강도시험 방법 ······························································································································ 6
• 3.2 응력해석 방법 ······························································································································ 7
• IV. 실험결과 및 고찰 ······································································································································ 9
• 4.1 HDPE배관 기계적 물성 저하 ···································································································· 9
• 4.2 HDPE배관 최대 등가응력 ········································································································ 12
• Ⅴ. 결론 ································································································································································ 19
• 참고문헌 ······························································································································································· 20
• ABSTRACT ··························································································································································· 21