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장기 저장연료의 열안정성 및 연료접촉 고무오링의 수명예측 연구
정근우(K. W. Chung),홍진숙(J. S. Hong),김영운(Y. W. Kim),한정식(J. S. Han),정병훈(B. H. Jeong),권태수(T. S. Kwon),서동욱(D. O. Suh),성민준(M. J. Sung),권영일(Y. I. Kwon) 한국트라이볼로지학회 2018 한국윤활학회지(윤활학회지) Vol.34 No.5
Thermal deterioration of fuel due to long-term storage influences engine performance and causes malfunctions. Fuel stability is usually evaluated via heat resistance and thermal stability during a brief heat shock at high temperature; storage stability in this scenario means that there is very little change in the quality of the fuel during long-term storage. In addition, rubber-based products such as oil seals, O-rings, and rubber hoses can influence the quality of the fuel. When these rubber products are in contact with fuel, they can swell, mechanically weaken, and occasionally crack, thus leaking low molar weight rubber and additives including plasticizer and antioxidant into the fuel to degrade its properties and shorten its useful lifetime. This study determines the thermal stabilities of three kinds of synthetic fuels by evaluating their low temperature kinematic viscosities, chemical composition changes via GC analyses, gross heat of combustion, and color changes. We evaluate the compression set of O-rings by immersing one NBR and two FKM rubber O-rings in the three synthetic fuel samples in airtight containers at variable storage temperatures for six months; from this, we estimate the lifetimes of the O-rings using the Power law model. There were very little changes in the chemical compositions and gross heat of combustion after six months of the experiment. The lifetimes are thus dependent on the materials of the rubber products, and in particular, the FKM O-ring was calculated to have a theoretical lifetime of 200 to 5,700 years. These results indicate that the synthetic fuels maintain their physical properties even after long-term storage at high temperatures, and the FKM O-ring is suitable for long-term sealing of these fuels.
이일영(I. Y. Lee),김지웅(J. W. Kim),강만곤(M. G. Kang),김영운(Y. W. Kim),송문기(M. K. Song) 한국동력기계공학회 2005 한국동력기계공학회 학술대회 논문집 Vol.- No.-
Governors control the revolution speed of heat engines such as diesel engines, steam turbines and gas turbines. Precise and prompt tests for the control performances of governors are essential both in governors' manufacturing processes and in governors' maintenance processes. In the conventional governor test systems controlled by analog type electronic controllers, the incorporation of heat engine's dynamics to the test system have been considered very difficult to realize. This study suggests a new governor test system controlled by a digital controller using a personal computer. The application of the digital controller to the test system instead of the analog type electronic controller have brought about the following advancements; (1) heat engine's dynamics could be implemented easily in the test system, (2) automatic test data acquisition both in steady state and in transient state enables us to save test time and to enhance the reliability of the tests.