상용 프로그램을 이용한 열병합 발전용 고압(HP)-중압(IP) 증기터빈 모델의 성능해석에 대한 연구

원종필,오승태,오정모 해양환경안전학회 2023 해양환경안전학회지 Vol.29 No.4

우리나라 열병합 발전소에서 운영되고 있는 최신 증기터빈의 출력과 효율 향상을 위한 첫 번째 기술적인 진보는 고온, 고압의 증기를 사용할 수 있는 소재 개발의 진척이라고 할 수 있다. 소재의 발전과 더불어 증기터빈의 내부효율 향상을 위한 설계적 노력의 결실로 높은 효율의 증기터빈이 제작되었다. 오랜 기간 운전 중인 증기터빈의 내부효율은 기계적 수명의 한계로 점차 손실이 발생하고 효율과 출력이 떨어지게 된다. 이러한 이유로 본 연구에서는 상용프로그램을 이용하여 열병합 발전소용 고압(HP)-중압(IP) 증기터빈의 증기유로 성능해석을 수행할 수 있는 모델을 개발하고 성능계산 방법을 제시하고자 한다. 증기터빈의 복잡한 성능계산방식으로 인해 증기터빈 실무자들에게 실질적으로 유용한 참고문헌이 될 수 있도록 주요 변수들을 제시하였다. 또한 증기터빈 성능계산에 필요한 열정산도 분석과 증기터빈 성능계산 결과의 적합성을 성능시험 결과와 비교 확인하였다.

개량형 C12A7계 광물계 급결제를 사용한 숏크리트의 장기강도 평가

원종필,황언종,이수진,이재호,장석부,Won, Jong-Pil,Hwang, Un-Jong,Lee, Su-Jin,Lee, Jae-Ho,Jang, Seok-Bu 한국터널지하공간학회 2014 한국터널지하공간학회논문집 Vol.16 No.2

본 연구에서는 숏크리트의 품질을 안정적으로 만들기 위해 초기 및 장기강도성능을 향상시킨 개량형$C_{12}A_7$계 광물계 급결제의 성능 평가를 실시하였다. 개량형 $C_{12}A_7$계 광물계 급결제는 기존 급결제들이 가지고 있는 장기강도 저하를 극복하고자 개발되었다. 개량형 $C_{12}A_7$계 광물계 급결제의 혼입량에 따른 성능을 평가하기 위해 실내에서 응결시간, 압축강도 및 휨강도를 실시하였다. 실험결과 응결시간은 개량형 $C_{12}A_7$계 광물계 급결제를 6%이상 사용하였을 때 기존 $C_{12}A_7$계 광물계 급결제에 비해 초결은 느리지만 종결은 빠르게 나타났다. 압축강도 및 휨강도는 기존의 $C_{12}A_7$계 광물계 급결제가 초기재령 3시간, 1일에서는 높게 나타났지만 7일 이후로 갈수록 개량형 $C_{12}A_7$계 광물계 급결제를 사용한 숏크리트의 강도가 증가하였다. 또한 실내실험에서 도출된 최적혼입률을 적용하여 현장 적용성을 평가하였다. 현장실험으로는 리바운드, 압축강도 및 휨강도를 실시하였다. 현장실험 결과 실내실험과 같이 개량형 $C_{12}A_7$계 광물계 급결제를 사용한 숏크리트의 장기강도성능이 우수하게 나타났다. This study was performed to evaluate the performance about Improved C12A7 based mineral accelerator (ICM) increased in initial and long-term strength. ICM was developed to overcome the long-term strength decrease in existing accelerator. To evaluate the performance of ICM according to addition rate, setting time, compressive strength, and flexural strength tests were conducted in laboratory. In results, initial setting time was slower, final setting time was faster than existing $C_{12}A_7$ based mineral accelerator (CM) when usage of ICM 6%. In compressive and flexural strength, existing CM was higher than ICM at 3hours and 1day. After 7days, strength of shotcrete using ICM was increased. Rebound test, compressive strength and flexural strength test with optimum addition rate through the laboratory test were conducted in field. Field experiment results were the same as laboratory test. Long-term strength performance of ICM was superior to existing accelerator.

복합열화 환경을 받는 콘크리트 시설물을 위한 보수용 폴리머 시멘트 복합체의 내구성능 향상에 관한 연구

원종필,박찬기,Won, Jong-Pil,Park, Chan-Gi 한국농공학회 2005 한국농공학회논문집 Vol.47 No.6

The purpose of this study is to improve the durability performance of polymer modified cement composites for repair of concrete under combined aging conditions. The experimental procedure was divided into three parts. First, the replacement level of mineral admixtures in polymer modified cement composites were determined in an experimental study based on a Box Behnken design. Second, the flow value, compressive strength and chloride permeability test of sixteen types of mixtures were conducted. Test results show that the polymer modified cement composites were effected on the improvement of the compressive strength and permeability performance. Third, the effects on the replacement level of silica fume mixture was evaluated by the compressive strength, chloride permeability, chemical resistance and repeated freezing and thawing cycles test. They demonstrated that the polymer modified cement composites using mixture of silica fume, fly ash, and blast furnace slag improved the durability performance.

노후 증기 터빈 리트로핏 성능 계산 기술에 대한 실증 연구

원종필,오승태,김은호,이상재 대한기계학회 2023 大韓機械學會論文集B Vol.47 No.8

Although many papers introduced methods for predicting the performance of steam turbines of old thermal power plants operating in the energy industry and approaching the results, several difficulties exist for field engineers to actually utilize them. Owing to these difficulties, general engineers struggle to overcome the barriers with the expertise of only a few turbine manufacturers at home and abroad. To overcome this, the performance of steam turbines for old power plants was evaluated using a program used for business based on an empirical research on an actual aging model such that working-level engineers in the turbine field could approach. On the basis of the empirical research on performance calculation technology, we propose an engineering approach such that field engineers can access it more easily, and we suggest a direction for practical use. 에너지 산업 현장에서 운영 중인 노후 화력 발전소의 증기터빈의 성능을 예측하고 그 결과를 접근하는 방법은 많은 문헌에서 소개되고 있으나 실제로 현장 엔지니어가 활용하기에는 많은 어려움이 있다. 이러한 성능예측과 검증은 국내외적으로 극소수의 터빈 제작사만이 보유한 전문기술로 진입장벽을 극복하기 어렵다는 것이 현장 공학자들이 느끼는 애로사항이다. 이러한 문제점을 해결하기 위해 터빈 분야 실무 엔지니어들도 접근할 수 있도록, 실제 사업용으로 운용되는 노후 발전설비를 모델로 프로그램을 사용하여 증기터빈의 유로 성능을 평가하였다. 성능계산 기술에 대한 실증연구 사례를 토대로 현장 엔지니어들이 보다 쉽게 접근할 수 있도록 엔지니어링 접근방법을 제시하고 실질적 활용이 될 수 있도록 방향을 제시하고자 한다.

연비향상을 위한 자동차용 열교환기 최신 기술 동향

원종필 대한기계학회 2014 기계저널 Vol.54 No.5

농업용 콘크리트 구조물을 위한 라텍스 개질 보수용 모르타르의 적정 배합비 도출

원종필,이재영,박찬기,박성기,Won, Jong-Pil,Lee, Jae-Young,Park, Chan-Gi,Park, Seong-Gi 한국농공학회 2007 한국농공학회논문집 Vol.49 No.2

The service life of agricultural concrete structures is designed in about 30 to 100 years, but actual service lift is estimated in an average 18 years. Therefore, as the service life of the agricultural concrete structures increases, necessity of repair by aging from various environment condition exposure increases. This study was to determinate the optimum mix proportion of latex modified repair mortar and to improve the durability performance of agricultural concrete structures. The physical and mechanical tests of latex modified repair mortar were performed. Tests of flow, compressive strength, flexural strength and bond strength tests were conducted. Test results show that the optimum nex proportion of latex modified repair mortar, when used in 5% latex volume fraction (weight of cement), 1.5% antifoaming agent (weight of latex), 0.2% PVA fiber volume fraction, 1:2 (binder-sand ratio), 10% silica fume replacement ratio (weight of cement), could result in best performance for the repair of agricultural concrete structures.

수중에 노출된 농업용 콘크리트 구조물 보수용 라텍스개질 모르타르의 적정 배합비 도출

원종필,이재영,박찬기,이상우,김완영,Won, Jong-Pil,Lee, Jae-Young,Park, Chan-Gi,Lee, Sang-Woo,Kim, Wan-Young 한국농공학회 2007 한국농공학회논문집 Vol.49 No.3

The purpose of this study was to determine the optimum mix proportion of latex modified mortar for agricultural underwater concrete structures repair. The experimental variables included a latex and antiwashout admixture amount, binder-sand ratio, water-binder ratio. This study were evaluated a repair performance and environment effect of latex modified repair mortar for agricultural underwater concrete structures. The pH test was conducted to evaluated the environmental effect and the flow test was peformed to evaluated the workability. Also, compressive, flexural and bond tests were conducted. Test results show that the optimum mix proportion of latex modified repair mortar for agricultural underwater concrete structures, was achieved by 1:1.5 binder-sand ratio, 5% latex ratio (weight of binder), 1.3% antiwashout admixture ratio (weight of binder), 0.33 water-binder ratio and 10% silica lune replacement ratio (weight of cement). The environmental effect and repair performance of optimum mix proportion satisfied all target performance.

엔진 냉각시스템의 열유동 해석 ( Thermal Fluid Analysis of Engine Cooling System )

원종필,방청세,박경석,정동화 대한기계학회 1998 대한기계학회 춘추학술대회 Vol.- No.-

광물질 혼화재를 혼입한 초속경시멘트 콘크리트의 투수 특성

원종필,공태웅,Won, Jong-Pil,Kong, Tae-Woong 한국농공학회 2005 한국농공학회논문집 Vol.47 No.3

The purpose of this study is to improve the performance of jet set cement, which mixed with the mineral admixtures such as silica fume, fly ash and ground granulated blast furnace slag. First, the test of mortar according to the substitute ratio of mineral admixtures were evaluated. And then using it obtained from test results, it was conducted with experiment of mechanical, physical and permeable characteristics of concrete. Laboratory test results showed that concrete substituted for $5\%$ of silica fume didn't have an effect on prominent performance relating to compressive strength. However it was superior to concrete in case of resistance of chloride permeation.

롤러다짐 댐 콘크리트의 효율적인 배합비 도출에 관한 연구

원종필,윤종환,김완영,Won, Jong-Pil,Yoon, Jong-Hwan,Kim, Wan-Young 한국농공학회 2004 한국농공학회논문집 Vol.46 No.1

Roller-compacted concrete(RCC) dam have gained acceptance worldwide in a relatively short time due to their low cost, which is derived in part from their rapid method of construction. And RCC has recently emerged as an economically attractive material for dam construction, replacing the use of conventional concrete and even challenging the economics of earthfill and rockfill embankment dams. There are existing two major mix design methods. one used in USA and the other used in Japan. In this study, proper mix proportions of concrete for RCC dam is obtained using method of compound their merit.