• 동력기계공학회지
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• 제13권6호
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• pp.35-42
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• 2009

The piping systems in the steam-driven power engines lie under the cyclic condition of thermal expansion and contraction by superheated steam. These phenomena might cause some severe damages on the pipes and the accessory devices. To avoid these damages, the calculation of the proper strength and the consideration of the reduced resultant forces on the materials are needed. In the present study, numerical investigations on the effects of the thermal deformation of the industrial piping system were performed with comparison of the design data. Commercial software, ABAQUS with the thermal-fluidic loadings based on the design conditions was used for the thermal stress analysis of the piping system. From the analysis of the initially-designed pipe supporters, the rearrangement was suggested to improve the piping design.

• 건축역사연구
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• 제15권2호
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• pp.7-22
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• 2006

The Industrial Revolution brought a variety of new forms of structure, and as a group they are usually called 'industrial architecture'. Steam engines contributed greatly to architecture with a unique structure called 'water tower' to provide water for steam engines, especially the adoption of it. This study is to examine the changes of the building materials and architectural features of the water towers of railway stations built in the early twentieth century in South Korea. This study also attempts to describe the modern features of the industrial architecture, which did not get a chance to be noticed. Through this examination on water tower, which is a part of industrial architecture with sheer integration of function and pure geometric form, we would like to find the meaning of modern architecture in Korea. As we can see in the Korean oldest railway station water tower constructed in masonry at Yeonsan Station in 1911, early water towers were divided into the masonry machine room and the steel water tank. However, the masonry structure was soon turned into concrete structure with its formal features maintained as it was. The steel water tank was also replaced with concrete structure. As a result, while its basic structure remained, concrete structure had substituted for the every components of water tower. Concrete-built water towers were the high-tech architecture of that time and the most perfect structures built in concrete. Nevertheless, the perfection of the water tower form and the technology it attained were not transferred to other modern and contemporary architecture in South Korea. Since the subject to railway station water towers was the Japanese government, and steam engines were replaced with diesels in the midst of a complicated domestic situation after the independence, the need for water towers in railway stations disappeared and therefore, it became ignored and was difficult to look over the architectural features and values of early railway station water towers.

• Nuclear Engineering and Technology
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• 제54권4호
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• pp.1482-1494
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• 2022

Power conversion cycles (Subcritical Steam, Supercritical Steam, Open Air Brayton, Recuperated Air Brayton, Combined Cycle, Closed Brayton Supercritical CO₂ (sCO₂), and Stirling) are evaluated for land-based nuclear microreactors based on technical maturity, system efficiency, size, cost and maintainability, safety implications, and siting considerations. Based upon these criteria, Air Brayton systems were selected for further evaluation. A brief history of the development and applications of Brayton power systems is given, followed by a description of how these thermal-to-electrical energy conversion systems might be integrated with a nuclear microreactor. Modeling is performed for optimized cycles operating at 3 MW(e) with turbine inlet temperatures of 500 ℃, 650 ℃ and 850 ℃, corresponding to: a) sodium fast, b) molten salt or heat pipe, and c) helium or sodium thermal reactors, coupled with three types of Brayton power conversion units (PCUs): 1) simple open-cycle gas turbine, 2) recuperated open-cycle gas turbine, and 3) recuperated and intercooled open-cycle gas turbine. Aeroderivative turboshaft engines employing the simple Brayton cycle and two industrial gas turbine engines employing recuperated air Brayton cycles are also analyzed. These engines offer mature technology that can facilitate near-term deployment with a modest improvement in efficiency.

• 만화애니메이션 연구
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• 통권46호
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• pp.63-84
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• 2017

파란 하늘을 나는 선명한 색의 비행체와 거대한 기계에서 뿜어져 나오는 증기의 압도적 이미지는 일본 애니메이션을 대표하는 미야자키 하야오 감독의 작품을 떠올리게 한다. 감독은 과거를 상징하는 산업시대의 기계장치인 증기기관과 미래의 장치인 비행체를 함께 제시하여 모호한 시공간을 구축한다. 이 특별한 시공간은 증기기관을 매개로 한 과거에 대한 향수(鄕愁)이며 비행체로 대표되는 과학과 미래를 향한 동경이다. 이는 현재의 시간이 아닌 과거와 미래의 혼재된 이미지를 기반으로 하는 스팀펑크(Steam Punk) 장르의 특성을 공유한다. 스팀펑크는 공상과학(Science Fiction)의 하위 장르로써 인간이 제어할 수 없는 방향으로 발전하고 있는 과학기술과 기계문명에 대한 근본적 회의와 미래 세계에 대한 낙관을 동시에 담고 있다. 또한 현재를 바라보는 인간의 기대와 실망, 이상과 미련이 투영되어 있다. 미야자키 하야오 감독의 작품 중 <바람계곡의 나우시카>(Nausicaa Of The Valley Of Wind, 風の谷の ナウシカ)와 <천공의 성 라퓨타>(Laputa: Castle In The Sky, 天空の城ラピュタ) 등은 이러한 특성을 분명히 보여준다. 이들 작품은 자연과 인간, 그리고 환경과 파괴에 대한 서사를 증기기관과 비행체로 시각화하여 과거와 미래가 동시에 존재하는 가상의 시공간을 스펙터클하게 구현함으로써 전 세계 팬들을 매혹한다. 그런데 자연과 환경, 공동체의 이상을 매력적으로 표현해 온 미야자키 하야오 감독의 작품에는 기묘하게도 전쟁과 세계 멸망의 이미지가 어김없이 등장한다. <붉은 돼지>(Crimson Pig, 紅の豚)에서는 실제 전쟁 시기를 시대배경으로 설정함으로써 현실세계의 서술로 나아가며, 심지어 <바람이 분다>(The Wind Rises, 風立ちぬ)에서는 일본의 제국주의 침략전쟁을 그리면서도 감독 자신의 존재론적 정체성과 주관적 관점을 낭만적 태도로 투사함으로써 다수의 관객을 당혹시킨다. 그리고 이러한 문제는 정도의 차이는 있으나 그의 작품 전반에서 발견된다. 이는 스팀펑크 장르가 현재의 문제를 마주하기보다 인간이 제어 가능했던 과거와 낙관적인 미래를 혼종하여 모호한 시공간을 그려내는 것과 마찬가지로 애매한 상태로 제시하고 있는 것이라 할 수 있다.

• Journal of Advanced Marine Engineering and Technology
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• 제18권4호
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• pp.13-24
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• 1994

The demand of clean energy, like liquefied gas(LNG), increase suddenly because it generates few polluting substances when burned and from the point of view with caloric value it generates ralatively less $CO_2$ gas than the other energy sources. LNG transpotion method of our country is marine transportion by ships because the LNG producing district is far away from Korea. Main engines for most LNG ships are steam turbines, and the efficiency of steam turbine is influenced by the degree of vacuum of main steam condenser. This paper introduce the design method of the vacuum system for high efficiency marine steam turbine. Especially, it is developed the CAD program for the large steam condenser and steam ejector. Also, it is designed the pilot plant including high pressure boiler for the performance test and maked a part of this plant.

• Nuclear Engineering and Technology
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• 제47권6호
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• pp.719-728
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• 2015

Following the Fukushima accident, a special safety inspection was conducted in Korea. The inspection results show that Korean nuclear power plants have no imminent risk for expected maximum potential earthquake or coastal flooding. However long- and short-term safety improvements do need to be implemented. One of the measures to increase the mitigation capability during a prolonged station blackout (SBO) accident is installing injection flow paths to provide emergency cooling water of external sources using fire engines to the steam generators or reactor cooling systems. This paper illustrates an evaluation of the effectiveness of external cooling water injection strategies using fire trucks during a potential extended SBO accident in a 1,000 MWe pressurized water reactor. With regard to the effectiveness of external cooling water injection strategies using fire engines, the strategies are judged to be very feasible for a long-term SBO, but are not likely to be effective for a short-term SBO.

• 동력기계공학회지
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• 제9권4호
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• pp.155-161
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• 2005

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.

• 한국자원리싸이클링학회:학술대회논문집
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• 한국자원리싸이클링학회 2006년도 고분자리싸이클링 심포지엄
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• pp.3-12
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• 2006

The main feature of these total technologies is that we can constitute the optimum treatment scheme fitting to the property of wastes, amount of wastes and energy requirement. For high moisture content wastes or biomass resources, high pressure steam process (MMCS) for crush, dry and deodorize wastes to produce high quality fertilizer of fuel is most appropriate. For dry or semi-dry solid wastes, the STAR-MEET system can be applied to produce low-BTU gases for power generation using duel fueled diesel engines of Stirling engines, and the REPRES and HyPR-MEET systems can be applied to produce hydrogen rich medium-BTU gas. For waste plastics and oils, liquefaction technology is best fit to produce light oil or kerosene equivalent fuel oils. These total technologies are completely different from the existent waste treatment technologies based on land-filling or incineration, and are expected to disseminate all over the world in the near future.

• Journal of Advanced Marine Engineering and Technology
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• 제16권5호
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• pp.6-16
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• 1992

Since world-wide oil shock on 1970s, many large size-low speed diesel engines, instead of steam turbines, are used for the industrial electric power generating plants due to their economic advantage of low specific fuel consumption. But it is very important to control their electric power fluctuation problems for the purpose of smooth parallel operation with existing power plants. In this paper the fluctuation problem of KEPCO Nam-cheju No.1 generator driven by diesel ngine(B & W 7K 60MC, 13931x138.5RPM) is investigated with analysis of torsional vibration of which 4th harmonic component is related to its power fluctuation. The problem can be improved by modification of cylinder arrangement and flywheel position in reverse sequence, equalizing the combustion gas pressure of all cylinder and installation of torsional vibration damper enlarged 30%(Je=7287Kg.m$^{2}$) and high quality balancing of generator rotor.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1993년도 제18회 학술대회 초록집
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• pp.77-84
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• 1993

Systems with journal bearings generally operate in large scale and under severe loading conditions such as steam generator turbines and internal combustion engines, in contrast to the machineries using rolling element bearings. Failure of the bearings in these machineries can result in the system breakdown. To avoid the time consuming repair and considerable economic loss, the detection of incipient failure in journal bearings becomes very important. In this experimental approach, acoustic emission monitoring is employed to the detection of incipient failure caused by intervention of foreign particles most probable in the journal bearing systems. It has been known that the intervention of foreign materials, insufficient lubrication and misassembly etc. are principal factors to cause bearing failure and distress. The experiment was conducted under such designed conditions as inserting alumina particles to the lubrication layer in the simulated journal bearing system. The results showed that acoustic emission could be an effective tool to detect the incipient failure in journal bearings.