• Journal of Hydrogen and New Energy
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• v.31 no.6
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• pp.578-586
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• 2020

There is growing interest worldwide in a hydrogen economy that uses hydrogen as an energy medium instead of hydrocarbon-based fossil fuels as a way to combat climate change. Since hydrogen has a very low energy density per unit volume at room temperature, hydrogen must be compressed and stored in order to use as an energy carrier. There are mechanical and non-mechanical methods for compressing hydrogen. The mechanical method has disadvantages such as high energy consumption, durability problems of moving parts, hydrogen contamination by lubricants, and noise. Among the non-mechanical compression methods, electrochemical compression consumes less energy and can compress hydrogen with high purity. In this paper, research trends are reviewed, focusing on research papers on electrochemical hydrogen compression technology, and future research directions are suggested.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.05b
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• pp.231-236
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• 1997

방사성물질의 수송 및 저장용기 등에 사용되는 실리콘고무계 및 수소 첨가된 비스페놀-A형 에폭시수지계 중성자 차폐재들의 인장강도, 압축강도, 비중, 무게, 수소함량 등에 방사선이 미치는 영향을 검토하였다. 방사선 조사선량의 증가에 따라 실리콘고무계 중성자 차폐재(KNS-101 및 102)들의 인장강도, 압축강도, 비중 등이 증가하는 경향을 나타내었으며, 차폐재의 무게는 거의 변화가 없었으나, 수소함량은 약간 감소하는 경향을 나타내었다. 또한 에폭시수지계 중성자 차폐재(KNS-201 및 202)들의 인장강도 및 압축강도는 0.1 MGy까지는 방사선 조사선량의 증가에 따라 증가하다가 0.1MGy 이상에서는 감소하는 경향을 나타내었으며, 조사선량의 증가에 따른 차폐재들의 비중, 무게 및 수소함량은 크게 변하지 않는 것으로 나타났다.

• Annual Conference of KIPS
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• 2023.11a
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• pp.681-684
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• 2023

우리나라의 수소연료전지 차량의 점유율이 매년 증가하고 있으나, 수소충전소 설비의 잦은 중단으로 수소연료전지 차량 운전자들이 제때 차량을 충전하지 못하는 불편이 발생하고 있다. 본 논문에서는 수소충전소 설비 중 Diaphragm을 사용하는 압축기의 이상 패턴을 탐지하는 Ensemble 모델을 통해 수소충전소에서 2023년 1월 1일부터 2023년 6월 28일 동안 수집된 데이터를 분석하였으며, 해당 기간 동안 발생했던 고장에 대해 2일전부터 이상 패턴이 10,000 이상 탐지되는 결과를 얻었다.

• Journal of the Korean Institute of Gas
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• v.17 no.5
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• pp.1-7
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• 2013

In this study, simulation work of HCNG refueling system was performed. The hydrogen was produced from steam reforming process by natural gas. The conversion of natural gas is increased as SCR is increased. but it was no significant difference more than 3 of SCR and fuel throughput is increased as GHSV is increased. Both conversion and fuel throughput levels was optimized when the $1700h^{-1}$ of GHSV. CNG was compressed from low pressure natural gas. For the mixing of $H_2$ and CNG is mixed with the high pressure conditions such as 400bar of $H_2$ and 250bar of natural gas. Single-stage compression was required more power than multi stage. So, multi stage compression was suggested for high pressure compression. We calculated the intermediate pressure to minimize total required power of compressors. The intermediate pressure for $H_2$ and natural gas were derived at 61 and 65 bar, respectively.

• Journal of Hydrogen and New Energy
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• v.3 no.2
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• pp.1-7
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• 1992

New type of metal hydride heat pump (MHHP) combined with hydrogen compressor was constucted for cooling purpose. A model for calculating the coefficient of performance (COP) is presented for MHHP which consisted of two different stages (enforced and natural stage), and compared with the experimental results. A concept of adiabatic compression work is introduced in the model on the basis of Carnot reversible analysis and the dependence of COP on the various operational parameters is discussed.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.5
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• pp.473-479
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• 2013

This study focused on a heavy-duty natural gas engine fuelled with HCNG (CNG: 70 vol%, hydrogen: 30 vol%) and CNG. To study the emission characteristics of an HCNG engine with high compression ratio, the exhaust gas of CNG and HCNG fuel were analyzed in relation to the change in the compression ratio at the half load condition. The results showed that the thermal efficiency improved with an increase in the compression ratio. Consequently, $CO_2$ emission decreased. CO emission increased with inefficient oxidation due to the low exhaust gas temperature. $NO_x$ emission with high compression ratio was increased at the same excess air ratio condition. However, $NO_x$ emission was not affected by a compression ratio exceeding ${\lambda}$ = 1.9 because of the same MBT timing.

• Journal of the Korean Institute of Gas
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• v.28 no.1
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• pp.85-99
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• 2024

As the proliferation of hydrogen electric vehicles accelerates, there is observed diversification in hydrogen refueling station models. This diversification raises safety concerns for different types of stations. This study conducted a quantitative risk assessment of a multi-vehicle hydrogen station, capable of simultaneously refueling cars, buses, and trucks. Utilizing Gexcon's Effects&Riskcurves Software, scenarios of fire and explosion due to hydrogen leaks were assessed. The study calculated the impact distances from radiative heat and explosion overpressure, and measured risks to nearby buildings and populations. The largest impact distance was from fires and explosions at dispensers and high-pressure storage units. High-pressure storage contributes most significantly to personal and societal risk. The study suggests that conservative safety distances and proper protective measures for these facilities can minimize human and material damage in the event of a hydrogen leak.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.225.2-225.2
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• 2010

전 세계는 온실 가스의 방출을 줄이기 위하여 기존의 화석연료를 대체할 수 있는 에너지를 찾기 위해 연구개발에 박차를 가하고 있다. 이러한 계속적인 연구에서, 전 세계의 국가들은 태양열, 풍력, 지열 및 수소에너지와 같이 화석연료를 대체할 다양한 가스를 조사해왔다. 대체에너지 중 수소 연료는 실제로 배출가스가 없기 때문에 가장 유망한 대안이라고 할 수 있다. 연료전지자동차용 연료로 수소를 사용하기 위해서는 저장합금, 액체 및 압축 상태로 저장할 수 있다. 이 중 세계 대부분의 자동차 메이커 들은 수소를 압축하는 방식을 채택하고 있으며, 주행거리를 확보하기 위하여 고압상태로 수소가스를 저장하는 방식을 사용한다. 수소연료전지 자동차용으로 고압의 수소를 저장할 수 있고, 자동차에 탑재할 수 있도록 가벼운 용기의 개발이 진행되고 있다. 이 중 Type3와 Type4 형태의 용기가 시범적으로 적용되고 있으며, 이러한 용기의 안전성을 확보하기 위한 기준들이 국 내외에서 개발되고 있다. 현재 국제기준 중 UN ECE의 WG.29에서 선진국들을 중심으로 수소연료전지 자동차용 용기의 안전성 평가를 위한 기준을 개발하고 있다. 본 연구에서는 ISO. 15869의 기술기준에 대한 안전성 분석과 미국의 SAE J2579의 기술 보고서에서 제시한 새로운 개념의 안전성 평가 기법을 기준으로 제정되고 있는 UN ECE WG.29의 draft초안을 비교하고, 향후 수소연료전지 자동차용 용기를 위한 국내기준의 방향을 제시하고자 한다.

• Journal of Hydrogen and New Energy
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• v.34 no.2
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• pp.141-148
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• 2023

The thermodynamic performance of the electrochemical hydrogen compressor was analyzed to perform a comparative analysis with the performance of the mechanical compressor. The performance was analyzed through the applied current and the measured voltage value. The test results showed that the efficiency of the electrochemical hydrogen compressor was high in the low current density range. In addition, it was confirmed that the amount of increasing compress work of the electrochemical hydrogen compressor is smaller than that of the mechanical compressor. Therefore, it is expected to have higher efficiency than mechanical compression when compressed with a sufficiently high-pressure range.

• Journal of Hydrogen and New Energy
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• v.23 no.6
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• pp.628-633
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• 2012

It was found that the pure hydrogen-air pre-mixture was self-ignited at a high compression ratio without any assisting method in room temperature, thus refuting the preconception that compression ignition of hydrogen engine was impossible. Therefore, in order to analyze the correlation of compression ignition condition at cold start with hydrogen HCCI engine clearly, the possibility of compression igniting compression ratio is investigated with the change of equivalence ratio and engine speed, experimentally. As the results, it is confirmed that the possibility of compression-igniting compression ratio at cold start was decreased by increasing equivalence ratio due to decreasing auto-ignition temperature. In addition, it is grasped that the possibility of compression-igniting compression ratio at cold start is decreased around 14.9% by increasing engine speed at same supply energy.