• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.246.2-246.2
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• 2010

본 연구는 저탄소 녹색성장의 국가 정책에 맞추어 주류 제조과정에서 발생하는 생전분발효 부산물인 주박(酒粕, 술지게미)을 펠릿화(pellet) 하는 것이 목적이다. 주류 제조과정에서 발생하는 주박을 100g당 물 100ml 비율로 섞어 충분히 반죽 후 녹즙기로 압축 성형화 하는 과정을 대신 하여 주박을 뽑았다. 이 주박을 온열 건조기에서 20시간이상 건조 시키면 완성이 된다. 주박펠릿은 폐기물을 재활용한 것이기 때문에 열량-가격대비를 비교해 보았을 때 등유 8950kcal-1000원/L, 경유 9050kcal-1433원/L, 면세경유 9050kcal-821/L, 우드 1812kcal-400원/kg, 주박 1989kcal-200원/kg으로 훨씬 저렴하며 열량도 높다. 주류업체에서 주박을 폐기물 처리하므로 가격 책정은 어렵다. $CO_2$ 발생량도 적어 온실가스를 절감시킬 수 있는 친환경적인 청정연료이다. 또한 연료로서 운송, 저장 및 보관이 편리하다. 주류업체도 주박 처리로 인해 연간 12억 정도 사용된다. 폐기물을 에너지화 함으로써 타 신재생에너지에 비해 초기 투자 비용이나 연료비가 저렴하다. 그리고 태우고 남은 회분은 토양개량제로 다시 재활용 되기 때문에 무해백익하다. 현재 폐목재를 사용한 우드펠릿은 원료를 수입해야 한다는 점과 삼림자원의 부족시 문제가 발생할 수 있다. 그리고 폐목재를 분쇄한 후 가공 및 성형을 해야 하기 때문에 주박이 효율성이 좋다. 현재 세계에서 가장 많이 사용되고 있는 석유나 화석연료의 매장량이 고갈 되어가고 있다. 하지만 주박은 술이 사라지지 않는 한 계속적으로 발생하기 때문에 무궁무진하게 사용이 가능하다. 또한 주류 제조시 발생하는 주박은 바로 성형 및 가공이 용이하다. 현재 주박으로 만든 펠릿은 전 세계적으로 전무하다. 막걸리 및 전통술의 특화사업으로 주박량은 더욱 증가하고 있다. 더욱이 2012년부터 해양 투기 금지로 주박 폐기물 처리가 힘들어진다. 주박 폐기물을 펠릿화해서 에너지원으로 사용하면 해결이 된다. 주박의 에너화를 통해 재생산의 열원으로 사용되고 펠릿을 연료원과 더불어 기계적인 시스템을 개발한다면 저탄소 녹색성장인 국가 정책과 부합된 미래형 에너지가 될 것이다.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.96-96
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• 2012

복합분자펌프는 기존의 터보분자펌프 turbine blade에 spiral grooved를 추가하여 초고진공(10-8Pa)에서 저진공(330Pa)까지 넓은 압력범위에서 사용할 수 있고 이 펌프를 사용함으로서 완전 oil free한 진공시스템을 만들 수 있는 특징을 가지고 있다. 특히, 회전체를 비접촉으로 지지하는 자기베어링 방식을 적용함으로써, 진동은 극히 작고 베어링수명은 길면서 중저진공에 대한 배기속도가 크고 임의의 방향으로 접속이 가능하여 반도체 및 디스플레이 제조 공정과 같은 첨단산업의 다양한 분야에 쉽게 적용되고 있으며, 그 적용 분야와 시장은 계속 성장하고 있다. 고 진공과 배기 속도의 달성을 위해서, 고속으로 이동하는 격면과 기체분자를 충돌시켜, 기체 분자를 원하는 방향으로 유도하는 작동원리를 가지고 있다. 특히 공기분자의 밀도가 매우 낮은 희박가스 상태에서 고속 회전하는 blade로 공기분자를 쳐내면서 작동됨으로써 날개의 상하 압력차에 의한 공기력보다도 날개의 고속회전이 매우 중요시되고 압력으로는 10-1 Pa 이하의 분자영역에서 그 성능을 최고로 발휘할 수 있다. 이러한 복합 펌프의 주요 장점은 다음과 같다. 1. 10-8 Pa (10-10 torr) ~ 10 Pa (1 torr) 까지 넓은 영역에서 배기가 가능하다. 2. 탄화수계의 대하여 높은 압축특성을 가지고 있고, 윤활유를 사용하지 않으므로 얻을 수 있는 진공상태가 고청정하다(oil free). 3. 정밀 5축제어 자기베어링으로 완전히 부상하여 회전함으로서 마모가 없고 진동이 최소화하였을 뿐 만 아니라, 또한 운전음도 거의 없다. 4. 설치조건에 제한이 없고 고장이 거의 없다. 특히 복합분자펌프는 탄화수소화합물이 없는 진공을 생성시키면서 구성요소가 간단한 반면 폭넓은 진공대역을 충족하기 때문에 산업계와 연구계의 주요 첨단 분야에서 광범위하게 사용되고 있으며, 최근 반도체 및 디스플레이, 바이오엔지니어링 등의 발전으로 적용분야가 넓어지고 있다.

• Plant Journal
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• v.16 no.1
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• pp.28-33
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• 2020

This study analyzes the requirements for international standardization by studying the approach to international standardization of equipment and bulk materials in the offshore oil & gas industry, and describes the prioritization of standardized equipment and the result of standardization in the first stage. Currently, international standardization activities can be classified into three activities. First, international standardization activities of bulk materials led by three major domestic shipbuilders, second, JIP33 equipment standardization activities led by IOGP, and finally, And standardization activities of UEJIP equipment centered on classification society. This study classifies various international standards applied in the offshore oil & gas industry, and introduces the activities of standardization activities of class-leading equipment and actual application examples.

• Journal of the Korean Society of Propulsion Engineers
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• v.5 no.2
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• pp.51-58
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• 2001

Supersonic, axisymmetric, jets issuing from several kinds of dual, coaxial, nozzles were experimentally investigated. Four different kinds of coaxial, dual nozzles were employed to characterize the major. features of the supersonic, coaxial, dual jets. Two convergent-divergent supersonic nozzles with different impinging angle on the jet axis of were designed to have the Mach number 2.0 and used to compare the coaxial jet flows with those discharging from two sonic nozzles. The primary pressure ratio was changed in the range from 4.0 to 10.0 and the assistant jet ratio from 1.0 to 4.0. The results obtained show that the assistant jets from the annular. nozzle affect the coaxial jet flows and an increase of both the primary jet pressure ratio and assistant jet pressure ratio lead to a longer supersonic length of the dual, coaxial jet.

• Journal of the Korea Convergence Society
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• v.9 no.4
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• pp.137-142
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• 2018

This paper is studied, as basic research for measuring the accurate fuel amount of the CNG tank by using the transmit-receive ultrasonic sensor, the receiving sensitivity according to changed the pressure inside the tank and the contact surface of the ultrasonic sensor is analyzed. Measurement was carried out while changing the contact surface of the tank and the sensor to three shapes of Point, Line, and Surface and charging the pressure in the tank at an interval of 1 bar from 0 bar to 5 bar. Experiment results, as the pressure in the tank increased the tendency of the received signal value of the ultrasonic sensor to decrease was confirmed. As the contact area between the tank and the sensor increased, the value of the received signal increased, but the noise also increased. The results of experiment, it is judged that accuracy can be improved by changing the contact surface of the sensor.

• Journal of Energy Engineering
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• v.11 no.3
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• pp.276-282
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• 2002

The process of energy separation in a low Pressure vortex tube with compressed air as a work-ing medium is studied in detail. Experimental data of the temperature of the cold and hot air leaving the vortex tube are presented. The variation of the maximum wall temperature along the inner surface of the vortex tube and the temperature distribution in a vortex tube provide useful information about the location of the stagnation point of the flow field at the axis of the vortex tube. Analysis of the results enabled to find the optimum length of the vortex tube, the optimum shape of the Throttle and the usefulness of the Sleeve. In this study Outer tube is used for the exhaust application. The hot gas flow is turned 180$^{\circ}$and passes the out-side of the vortex tube a second time heating it. From this geometric setup of a vortex tube He effects of energy separation and the prediction of the ignition of Diesel Soot is presented by experimental data.

• Fire Science and Engineering
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• v.30 no.2
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• pp.43-48
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• 2016

One of the main problems with gaseous fire extinguishers is the decrease in fire suppression capability due to the leakage of the fire extinguishing agents, either naturally or caused by obsolete equipment. Therefore, in this study, a real-time detector module for monitoring pressure leakages was developed and an assessment on its performance was carried out. Currently, there are no domestic or global standards for testing pressure leakage detection systems. Therefore, similar global standards, such as ISO 7240 and FM 1421, and the domestic law on "Receiver type-approval and technical standards for product inspection" were used as a reference for assessing the performance of the newly developed module. Its basic performance was assessed by applying compressed air to the module, and, as a result, the minimum working pressure was identified as 0.3 bar. Its environmental qualification was carried out to confirm the proper functioning of the module in different climates and the module was confirmed to function properly at both high ($50^{\circ}C$) and low ($-10^{\circ}C$) temperatures.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.378-383
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• 2005

This experimental study presents the results of the cooling performance test of a $CO_2$ heat pump system for fuel cell vehicles. The experimental facility provides the cool ing and heating environment for cabin and heat releasing component. The test loop is designed to target the cooling capacity of 5kW and its coefficient of performance (COP) of 2.2. The cooling performance of the heat pump system is strongly dependent on the refrigerant charge and the degree of superheat. We carried out basic experiments to obtain optimum refrigerant charge and the degree of superheat level at the internal heat exchanger outlet. The heat pump system for fuel cell vehicles is different from that of engine-driven vehicles, where the former has an electricity-driven compressor and the latter has the belt-driven (engine-driven) compressor. In the fuel cell vehicle, the compressor speed is an independent operating parameter and it is controlled to meet the cooling/heating loads. Experiments were carried out at cooling mode with respect to the compressor speed and the incoming outdoor air speed. The results obtained in this study can provide the fundamental cool ing performance data using the $CO_2$ heat pump system for fuel cell vehicles.

• Journal of Trauma and Injury
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• v.24 no.2
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• pp.129-135
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• 2011

Purpose: During August 2010, a natural gas fuel cylinder on a bus exploded in downtown Seoul, injuring 20 citizens. This kind of blast injury has never been reported in Korea before. Thus, the goal of this study was to review the clinical features of these victims to help physicians manage similar cases and to understand the risk factors associated with blast injuries in everyday life. Methods: Twenty (20) victims who visited nearby emergency departments, and 3 peoples left hospital without care. Seventeen (17) victims were included in this study, and the following factors were investigated: age, sex, type of hospital, diagnosis of injury, injury mechanism, position of victim (in-bus/out of bus), classification of injury severity with START (simple triage and rapid treatment), and classification of injury according to the mechanism of the blast injury. Results: The victims included 8 males (47%), 9 females (53%). The mean age was $37.5{\pm}12$. Thirteen (13) victims were transferred to two tertiary hospitals, and 4 were transferred to two secondary hospitals. The types of injury were 3 fractures, 2 ligaments injuries, 6 contusions, 4 abrasions, and 3 open wounds (one of them was combined fracture). According to START classification, 17 victims were 1 immediate, 11 minor, 5 delayed, and no death. Classifications according to the mechanism of the blast injury were 1 primary injury, 6 secondary injuries (2 of them combined other mechanism), 3 tertiary injuries and 9 quaternary injuries. Conclusion: Trauma care physicians should be familiar with not only the specific types of injuries from blast accidents, but also the potential accidents that may occur in public facilities.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.23 no.1
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• pp.32-37
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• 2011

The present study has been conducted to propose an algorithm regarding real-time load estimation of a gas engine-driven heat pump. In the study, thermal load of an indoor unit is estimated in terms of air-side and refrigerant-side. The air-side estimation is based on a typical heat exchanger model and is found to be in good agreement with experimental data. When it comes to the refrigerant-side load, a pressure difference across a valve must be estimated. For the estimation, it is assumed to be proportional to a bigger pressure difference that is available either by measurement or by estimation. Relative good agreement between the air- and refrigerant-sides suggests that the assumption may be plausible for the load estimation. The summed flow rate of all of indoor units is in good agreement with the throughput of the compressor which are calculated from the manufacturer's software. Accordingly, estimated thermal loads are also in good agreement. The proposed algorithm may be further developed for improved control algorithm and fault diagnosis.