가스터빈 블레이드의 막냉각 효율 측정을 위한 PSP 기법의 적용

서현재 ( Hyun Jae Seo ),강영준 ( Young Jun Kang ),곽재수 ( Jae Su Kwak ) 한국액체미립화학회 2018 한국액체미립화학회 학술강연회 논문집 Vol.2018 No.-

The film cooling technique is commonly applied to protect the high temperature components of gas turbines from the high temperature combustion gas. In this study, the pressure sensitive paint(PSP) technique which has been widely used in the gas turbine film cooling study is introduced. The principle of the PSP technique, test facility for the technique, and some examples of the application has been presented and the possible error of the technique is also discussed.

외관검사를 통한 한국형 철근자동가스압접기의 압접성능 연구

서덕석 한국건축시공학회 2008 한국건축시공학회지 Vol.8 No.6

This study is focused on the welding performance of automatic gas pressure welding machine adapted to korean construction site by external appearance investigation As gas pressure welding is more economical and has good performances compared with other steel bar jointing methods, as arc welding and mechanical joint etc, in Japan, the gas pressure welding is one of the typical connection of steel reinforcement when connecting the D29 and thicker steel bars, But in Korea, gas pressure welding joint method is not widely used caused by the shortage of skilled workers. so to activate the gas pressure welding in Korea, the automatic gas pressure welding machine is developed In this study, the welding performances of gas pressure welding joint samples using korean automatic gas pressure welding machine are measured by external appearance investigation - blown diameters, blown length, welding face disagreement, central axis eccentric ratio, bending, sag and crack. The results of welding performances on the gas pressure welding joint samples show that samples are satisfied with the standard value regulated in KS D 0244 and JIS Z 3120. This study is focused on the welding performance of automatic gas pressure welding machine adapted to korean construction site by external appearance investigation As gas pressure welding is more economical and has good performances compared with other steel bar jointing methods, as arc welding and mechanical joint etc, in Japan, the gas pressure welding is one of the typical connection of steel reinforcement when connecting the D29 and thicker steel bars, But in Korea, gas pressure welding joint method is not widely used caused by the shortage of skilled workers. so to activate the gas pressure welding in Korea, the automatic gas pressure welding machine is developed In this study, the welding performances of gas pressure welding joint samples using korean automatic gas pressure welding machine are measured by external appearance investigation - blown diameters, blown length, welding face disagreement, central axis eccentric ratio, bending, sag and crack. The results of welding performances on the gas pressure welding joint samples show that samples are satisfied with the standard value regulated in KS D 0244 and JIS Z 3120.

산업단지 고압매설배관 안전관리 향상방안 연구

최현웅(Hyun-Woog Choi),이동민(Dong-Min Lee),김진준(jin-jun Kim) 한국가스학회 2018 한국가스학회지 Vol.22 No.5

국내산업단지 내 고압 매설배관은 장기사용배관이 많고 독성·가연성·불활성 등 고압가스는 물론 다양한 유해화학물질이 한도로 내에 복잡하게 매설되어있어 다양한 타공사 등 사고 발생 시 인접하여 매설된 다른 배관에 손상을 미칠 수 있어 높은 수준의 안전관리가 요구되고 있다. 이에 본 연구에서는 고압가스매설배관과 도시가스매설배관 안전관리실태를 심층비교분석을 통하여 고압가스 매설배관의 효율적인 안전관리방식 도출에 활용하고자한다. pressure buried pipes in domestic industrial estate have many long-term use pipes, Toxic, flammable, Inflammable, etc. as well as a variety of toxic chemicals are embedded in a complex be buried, A high level of safety management is required as it can damage other pipes installed nearby in the event of accidents such as various external interference. Therefore, in this study, the safety management practices of high-pressure gas distribution and urban gas distribution are utilized to derive efficient safety management methods for high-pressure gas installation piping through in-depth comparative analysis.

외부 유입 가스 조절을 통한 연료전지 구동 성능 안정화

장한샘 ( Hansaem Jang ),박영은 ( Youngeun Park ),이재영 ( Jaeyoung Lee ) 한국공업화학회 2018 공업화학 Vol.29 No.5

연료전지는 높은 연료유연성을 갖고 있어, 탄소 및 탄화수소 등을 통해서도 전기를 생산할 수 있다. 하지만 이러한 연료원을 사용한 경우, 불안정한 장기 구동성능이 종종 관측된다. 본 연구에서는 반응기 내부에 존재하는 탄화수소가 장기 구동성능을 불안정하게 함을 밝힌다. 본 연구진은 비활성기체인 아르곤을 이용하여 산화극 반응기 내부의 가스화 경로를 예측하고, 이를 통해 탄화수소의 영향을 억제하여 불안정한 장기 구동성능을 극복한다. 더 나아가, 산화극 반응기 내부에 이산화탄소를 공급하여 역부드아반응을 유도한다. 역부드아반응을 통해 탄소연료전지에서 연료로 사용될 수 있는 일산화탄소를 만들어낸다. 과도한 이산화탄소의 주입은 오히려 연료손실 등의 문제를 야기함을 확인한다. 따라서, 본 연구에서는 이산화탄소 공급량의 최적화가 중요함을 밝히고, 이를 통해 연료전지 구동 성능을 안정화한다. Fuel cell is one of the promising electrochemical technologies enabling power production with various fuel sources such as hydrogen, hydrocarbon and even solid carbon. However, its long-term performance is often unstable and unpredictable. In this work, we observed that gasification-driven hydrocarbons were the culprit of unpredictability. Therefore, we controlled the presence of hydrocarbons with the help of external gas supply, i.e. argon and carbon dioxide, and suggested the optimal amount of carbon dioxide required for predictable fuel cell operations. Our optimization strategy was based upon the following observations; carbon dioxide can work as both an inert gas and a fuel precursor, depending on its amount present in the reactor. When deficient, the carbon dioxide cannot fully promote the reverse Boudouard reaction that produces carbon monoxide fuel. When overly present, the carbon dioxide works as an inert gas that causes fuel loss. In addition, the excessive carbon monoxide may result in coking on the catalyst surface, leading to the decrease in the power performance.

DME 예혼합 압축착화 엔진에서 배기가스 재순환의 영향

장진영(Jinyoung Jang),염기태(Kitae Yeom),배충식(Choongsik Bae) 한국자동차공학회 2007 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

The combustion and exhaust emission characteristics were investigated in an DME fueled HCCI engine with EEGR(external exhaust gas recirculation) and iEGR(internal exhaust gas recirculation). The effects of EEGR and iEGR on HCCI engine were compared each other under combustion and emission results. The effect of EEGR on HCCI engine was a contrary to the effect of iEGR. In case of increasing EEGR rate, start of auto-ignition was retarded and bum duration was extended. Due to these, indicated mean effective pressure was increased. Hydrocarbon(HC) and carbon monoxide(CO) were increased due to EEGR by low temperature of combustion. In case of increasing iEGR, start of auto-ignition was advanced and bum duration was reduced. Due to these, indicated mean effective pressure was decreased and pumping mean effective pressure was increased. HC and CO were decreased due to iEGR by increasing mixture temperature.

Life Cycle based Assessment of Environmental Impacts of External Walls in Residential Buildings

( Serik Tokbolat ),( Farnush Nazipov ),( Jong R. Kim ),( Ferhat Karaca ) 한국폐기물자원순환학회(구 한국폐기물학회) 2019 ISSE 초록집 Vol.2019 No.-

Sustainable development is a complex concept that requires a robust set of tools to assess impacts caused by various processes and products to the environment and socio-economic well-being of society. Buildings throughout their life cycle cause significant impact to the processes of global climate change and depletion of natural resources. To reduce these impacts it is imperative to evaluate environmental influences associated with all the stages of a building's life. Life Cycle Assessment (LCA) is one of the key and most used models in assessment of environmental performance of materials and processes. The aim of this study is to analyze the whole life cycle of external walls of 4 different noncommercial buildings in Astana, Kazakhstan (schools of different age and varying building envelopes) in terms of embodied energy and GHG emissions. The necessary data and information such as energy consumption, types, specifications and origins of materials used in external walls, maintenance routines and activities, and other relevant parameters were obtained from the building management and relevant construction companies. All the gathered data were analyzed using LCA approach. Preliminary findings suggest that operational stage contributes to more than a half of the GHG emission in all the cases. Building age (e.g. old or new) and specifications of materials used in external walls (e.g. the materials from local or foreign producers) show significant variations in terms of the embodied energy levels and GHG emissions. In addition to selection of materials, their delivery plays a significant role in the whole life-cycle performance of the building. Furthermore, obtained results suggest potential ways of reducing the overall environmental impact of the external wall components.

케틀보일러를 활용한 압축 공기의 열회수 및 열회수 열원에 따른 가스복합발전 시스템의 성능 변화

김도훈(Dohoon Kim),김민수(Minsu Kim) 대한기계학회 2022 대한기계학회 춘추학술대회 Vol.2022 No.11

Net-zero policy against climate change is making a transition to renewable energy based generation. However, due to the unstable supply of renewable resources, gas turbine generation is gaining interest which releases less carbon and can be operated rapidly. This study presents the gas turbine combined cycle utilizing a kettle boiler as an external cooler showing improvement in performance. The study analyzed the performance of the combined cycle by changing the steam source that the kettle boiler generates. The result shows that applying a kettle boiler type external cooler improves the performance significantly and multi-step heat recovery gains better performance with the same amount of heat transferred.

케틀보일러를 활용한 압축 공기의 열회수 및 열회수 열원에 따른 가스복합발전 시스템의 성능 변화

김도훈(Dohoon Kim),김민수(Minsu Kim) 대한기계학회 2022 대한기계학회 춘추학술대회 Vol.2022 No.11

Net-zero policy against climate change is making a transition to renewable energy based generation. However, due to the unstable supply of renewable resources, gas turbine generation is gaining interest which releases less carbon and can be operated rapidly. This study presents the gas turbine combined cycle utilizing a kettle boiler as an external cooler showing improvement in performance. The study analyzed the performance of the combined cycle by changing the steam source that the kettle boiler generates. The result shows that applying a kettle boiler type external cooler improves the performance significantly and multi-step heat recovery gains better performance with the same amount of heat transferred.

셰일가스 도입으로 인한 전원믹스 재구성 및 환경 영향 분석

최나래,여민주,김용표 한국입자에어로졸학회 2014 Particle and Aerosol Research Vol.10 No.1

In line with the expected price reduction of natural gas associated with the introduction of shale gas, it is expectedthat the optimal power mix for the electric power generation be changed. In this study, the reconfigured power mix is estimated with the varying natural gas price by using the Screening Curve Method (SCM). It is found that about3% and 9% coal in the overall power mix is replaced with natural gas if the natural gas price falls 20% and 40%of the current price, respectively. It is also found that the reconfigured power mixes would provide the reduction of the emissions of air pollutants which are equivalent to 369 and 807 MUS.

친환경교통수단으로서 KTX의 역할과 기대

방연근 한국철도학회 2006 철도저널 Vol.9 No.2

Green gas Emissions Trading System(ETS) came into effect in the Europe last year 2005. All transport modes have tried to reduce green gas emission and EU member countries are promoting the use of environmental friendly transport mode to avoid economic loss due to green gas emission. Besides ETS, rapidly rising of oil price and peak oil urge to invest more in the environmental friendly public transport mode and to discourage the use of private cars. The operation of KTX is estimated to bring external cost reduction up to 570 bil. won in 2004 based on European external unit costs of transport modes. This result implies that the expansion of high speed rail network and reconsideration of East-West high speed rail network which is not considered because of weak economic validity is required.