• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2010년도 제35회 추계학술대회논문집
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• pp.748-751
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• 2010

로켓을 발사하기 위해서는 발사대에 로켓을 세워놓고 추진제와 고압가스 등을 충전한 다음 원격제어로 로켓을 발사하게 된다. 로켓 발사대로는 지상저장탱크에 고압으로 저장되어 있는 고압가스가 여러 종류의 압력조정기를 통과하여 운용압력으로 감압되어 공급된다. 로켓 발사시에는 발사통제실에서 원격으로 모든 운용이 이루어지기 때문에 압력조정기 전단에는 급격한 가스 공급이나 압력변동 등으로 인하여 운용압력을 벗어나거나 압력조정기가 파손되는 경우가 발생할 수 있다. 본 논문에서는 고압가스가 안정적으로 감압되어 발사대로 공급되기 위한 고압가스감압시스템 최적화 설계기법을 고찰하였다.

• 한국가스학회지
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• 제18권3호
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• pp.60-66
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• 2014

본 연구에서는 국내 매설 고압가스배관의 사고빈도 데이터 구축 시 활용할 수 있도록 국외에서 발표하고 있는 고압가스배관 사고빈도 데이터에 대해 고찰 하였다. 고압가스배관 사고빈도 데이터의 대표적인 것으로는 미국의 DOT, 유럽의 EGIG 및 영국의 UKOPA가 있다. 국외 사고빈도 데이터의 국내 적용 가능성을 확인하기 위하여 이들을 비교 분석한 결과 EGIG 데이터가 국내 실정에 더 적합하였다. EGIG 8차 보고서의 사고빈도 데이터를 사용하여 비선형회귀분석을 수행한 결과 배관 설치 연도에 따른 지수형의 곡선을 얻었다. 향후 전체 사고빈도의 약 50%를 차지하고 있는 타공사 부분과 국내 데이터와 국외 데이터의 합성에 대한 집중적인 연구가 필요하다.

• 한국기계가공학회지
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• 제17권6호
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• pp.151-157
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• 2018

In this study, we have developed a composite pressure vessel that is compact and can store refrigerant at high pressure to increase the refrigerant volume. The composite pressure vessel is made of aluminum-based duralumin, which has high rigidity and excellent elongation in the inner liner, considering the characteristics of products in the aerospace and defense industry, where the safety of the applied product is considered as a priority. High strength carbon fiber was applied to the outside. In order to evaluate the performance of the developed product, burst test and cycling test were carried out. In burst test, an excellent safety margin equivalent to 2.7 times the operating pressure was obtained. In cycling test, a stable failure mode in which 'pre-burst leak' occurs is proved and the soundness of the product is proved.

• 동력기계공학회지
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• 제10권4호
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• pp.31-37
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• 2006

In this study, the ability for the function of double pipe inserted liquid pipe with small diameter in the gas pipe with large diameter for the circulating of liquid of high temperature and high pressure and low temperature and low pressure at the same time is presented. And in this double pipe, liquid pipe of high temperature and pressure is used to connect condenser and expansion valve and gas pipe of low temperature is used to connect evaporator and compressor. Also, when liquid refrigerant of high temperature and gas refrigerant of low temperature is circulated by reversed flow in the double pipe. The contribution of liquid gas heat exchange pipe is studied by comparison of the effect of heat transfer by temperature difference when liquid pipe and gas pipe is installed separately.

• 한국가스학회지
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• 제18권2호
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• pp.28-34
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• 2014

일반적인 천연가스 정압기지에서는 압력제어밸브를 이용하여 고압으로 수송되는 천연가스를 감압하여 내보낸다. 이 과정에서 버려지는 폐압에너지는 터보팽창기를 도입하여 추가적인 전력생산이 가능하나 터보팽창기를 통과하는 유체에서는 감압에 의한 Joule Thompson 효과에 의하여 온도가 급격히 떨어져 파이프라인 외부에 동결을 일으키거나 파이프라인 내부에 메탄하이드레이트와 같은 고체 물질이 형성될 위험이 있다. 현재 터보팽창기를 채용한 천연가스 정압기지에서는 냉열발생에 따른 부작용을 방지하기 위하여 터보팽창기의 전단에 보일러를 설치하여 팽창 전 천연가스를 예열하고 있다. 용융탄산염연료전지와 같은 고온 연료전지는 천연가스를 연료로 사용할 수 있고 친환경적인 고온 배출가스를 방출하며 동시에 추가적인 전력을 생산하여 시스템의 효율을 높일 수 있다. 이 논문에서는 천연가스 정압기지에 용융탄산염연료전지와 터보팽창기를 설치하여 얻을 수 있는 열역학적 이득에 대해서 연구하였다. 연료전지를 기저부하로 사용함에 따라서 얻을 수 있는 이익에 대하여 분석하였다.

• 한국정밀공학회지
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• 제25권7호
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• pp.124-130
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• 2008

The effect of nitrogen gas pressure in arc ion plating on surface properties of the TiN-coated high speed steel(SKH51) is presented in this paper. The surface roughness, micro-particle, micro-hardness, coated thickness, atomic distribution of TiN, and adhesion strength are measured fur various nitrogen gas pressures. It has been shown that the nitrogen gas pressure has a considerable effect on the surface roughness, adhesion strength, atomic distribution of TiN, and surface deposition of TiN of the high speed steels but that it has little influence on the micro-hardness and coated thickness.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2005년도 춘계학술대회 논문집
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• pp.156-161
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• 2005

Dynamic flow characteristics of a solenoid valve are affected by pressure difference in inlet and outlet of orifice, gas temperature, and supply voltage of a coil. In this paper, the dynamic flow characteristics for deviations of various conditions are studied Static and dynamic flow for variation on-time of a solenoid valve open signal are measured in basic bench test. The solenoid valve is applied to a compressed natural gas(CNG) engine test for validation of flow control performance. The experimental results show that flow of high pressure gas can controlled precisely by using a solenoid valve.

• International Journal of Automotive Technology
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• 제7권4호
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• pp.391-397
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• 2006

The soot yield has been studied by a premixed propane-oxygen-inert gas combustion in a specially designed disk-type constant-volume combustion chamber to investigate the effect of pressure, temperature and turbulence on soot formation. Premixtures are simultaneously ignited by eight spark plugs located on the circumference of chamber at 45 degrees intervals in order to observe the soot formation under high temperature and high pressure. The eight converged flames compress the end gases to a high pressure. The laser schlieren and direct flame photographs with observation area of 10 mm in diameter are taken to examine the behaviors of flame front and gas flow in laminar and turbulent combustion. The soot volume fraction in the chamber center during the final stage of combustion at the highest pressure is measured by the in-situ laser extinction technique and simultaneously the corresponding burnt gas temperature by the two-color pyrometry method. The changes of pressure and temperature during soot formation are controlled by varying the initial charging pressure and the volume fraction of inert gas compositions, respectively. It is found that the soot yield increases with dropping the temperature and raising the pressure at a constant equivalence ratio, and the soot yield in turbulent combustion decreases as compared with that in laminar combustion because the burnt gas temperature increases with the drop of heat loss for laminar combustion.

• 한국자동차공학회논문집
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• 제8권4호
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• pp.10-17
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• 2000

This work presents an investigation of aerodynamic characteristics of fuel spray injected from a high pressure hollow cone swirl injector into a constant volume chamber. Laser tomography visualization was used to interrogate the fuel and air mixing characteristics and the effect of chamber pressure and temperature increase was analyzed, Preliminary results on spray development showed that mixing effect tends to increase with the increase of injection pressure and chamber gas pressure yielding a decrease of spray penetration and an attenuation of well-defined vortex structure. Topological analysis of the spray structure has been performed to initiate the understanding of mixing and vaporization process. For the present experimental conditions fuel injection pressure and chamber gas pressure appear as the dominant factors which govern the transient mixing characteristics. Moreover spray atmixation characteristics are improved by increasing chamber gas temperature.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 추계학술대회 논문집
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• pp.193-196
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• 2007

We developed and tested the high pressure hydrogen gas cylinder(type4) for fuel cell vehicle. The working pressure is 350bar. We conducted material tests, production tests and design qualification tests on the developed cylinders according to modified NGV2-2000(hydrogen). The high pressure hydrogen gas cylinder met all the design qualification requirements of ANSI/CSA NGV2-2000 and acquired NGV2 certification from independent inspection agency.