• 한국공작기계학회논문집
• /
• 제15권1호
• /
• pp.76-81
• /
• 2006

Modem after-treatment technology has been developed variously in order to decrease exhausted emission in diesel engine. However, it seems very difficult to comply with updated stringent emission standards. Specially, it has been many years that exhaust gas from gasoline automobile rather than from diesel is the major object concerned by Korea and other countries, and it is strongly required on the reduction techniques on harmful NOx and PM among those compositions. Thus, this research focused on the electronic control EGR and the target for this research is heavy-duty turbo-diesel engine with EGR technology(High pressure route and low pressure route system).

• 비파괴검사학회지
• /
• 제24권4호
• /
• pp.371-377
• /
• 2004

원자력 발전소의 터빈에서 운전 연수 증가에 따라 pin finger형 블레이드 루트부에 균열이 발생하는 문제점이 발생되었다. 블레이드 루트부에 대한 비파괴검사는 매 계획 예방 정비기간 동안 수동 초음파 검사를 통하여 수행되어 왔으나, 검사의 신뢰성을 확보하기 위해 해당 설비에 대한 자동 초음파 검사 기술 개발의 필요성이 대두되었으며, 이에 따라 자동 초음파 검사 장비 및 검사 기술을 개발하였다. 개발된 검사 장비의 적용성을 확인하기 위해 계획 예방 정비 기간 중 저압터빈 2, 3단 블레이드 루트부에 대한 자동 초음파 검사를 수행하고, 다양한 형태의 터빈 검사에 확대 적용 가능성을 확인하였다.

• 한국소음진동공학회논문집
• /
• 제19권12호
• /
• pp.1281-1288
• /
• 2009

Variation of dynamic characteristics of a low pressure turbine blade with crack length is studied in this paper via both experiments and finite element model. Since most of the turbine blades used in domestic power plants are imported from abroad, it is necessary to understand their dynamic behavior in advance. When experimentally obtained natural frequencies and mode shapes are compared with those from FEM results, they are close to each other in their magnitude. Then, it is more feasible to use finite element model for analyzing the dynamic characteristics of a blade under various operation conditions (rotation speed, temperature, etc) as well as with a crack in the blade.

• 한국자동차공학회논문집
• /
• 제10권6호
• /
• pp.59-64
• /
• 2002

The effects of EGR on emissions were investigated by using a six-cylinder, 8 litre, turbo-charged, heavy-duty diesel engine with a low pressure route EGR system. The experiments were performed at various engine loads while the EGR rates were set from 0% to 30%. Hot and cooled EGR are achieved without cooling and with cooling respectively. To verify the possibility of EGR technology for the applications, test were performed with steady state test cycle. It was found that the exhaust emissions with the EGR system resulted in a very large reduction in oxides of nitrogen at the expense of higher smoke and PM emissions. Increasing the EGR rate leads to deteriorating specific fuel consumption and power at lower speed and higher load. Also, the reduction rates of NOx emissions for hot and cooled EGR are similar.

• 한국산학기술학회논문지
• /
• 제3권1호
• /
• pp.58-62
• /
• 2002

본 연구는 기관의 성능과 배출가스의 ECR 효과을 대한 것으로 기관은 6실린더 11리터의 대형터보디젤기관이며 ECR 방식은 저압루트시스템을 적용하였다. EGR 작동방식은 기계시이며 터빈 출구로부터 압축기 입구로 재순환시키는 방식이다. 또한 실험은 기관회전수와 부하별로 변경시켰으며 ECR율은 4%와 8%로 고정하여 실험하였고 그 결과를 기존 기관의 성능 및 배출가스결과와 비교 분석하였다. 따라서 본 연구의 목적은 대형터보디젤기관에 폭넓은 작동범위에서 ECR에 의한 기관 및 배출가스 성능에 미치는 영향을 고찰하고자 한다.

• 한국압력기기공학회 논문집
• /
• 제9권1호
• /
• pp.8-14
• /
• 2013

Steam turbine blades and discs of nuclear power plants are one of the most highly stressed areas of turbine rotor, and periodic inspection of the blade roots is essential for monitoring integrity and preventing turbine failure. Ultrasonic technique is applied for volumetric inspection of blade root. However, the complexity of blade root geometry imposes challenges to inspection of blades and discs. Recently, phased array ultrasonic inspection technology is being applied to numerous power generation inspection applications including turbine rotor. The phased array ultrasonic technique requires customized inspection wedges which are generally necessary to generate effectively higher incident angle. But the usage of this wedge can cause access limitation for the lower stage blades of turbine because of the wedge front length. Therefore, the shear wave phased array probe which can generate high inspection angle without wedge is essentially necessary. In this study, feasibility study is conducted for the shear wave phased array ultrasonic probe application to blade and disc inspection. As results, the experimental results show that the shear wave phased array probe can detect the flaw and measure its size with reliable accuracy. Therefore if this shear wave phased array probe is applied to field inspection of blade and disc, more reliable inspection is expected for turbine having access limitation.