비열플라즈마와 라디칼을 이용한 디젤엔진의 매연 및 NO 제거 특성

장영준,최승환,김규보,전충환,Jang, Yeong-Jun,Choe, Seung-Hwan,Kim, Gyu-Bo,Jeon, Chung-Hwan 대한기계학회 2002 大韓機械學會論文集B Vol.26 No.4

We are facing the serious environmental pollution difficulties such as acid rain, green house effects, etc. The gaseous matter NOx, SOx, VOCs which are regarded as main factors for these current pollutions are mainly emitted from power plants and vehicles. Therefore several leading countries are regulating the emissions strictly, especially the exhaust emissions from a Diesel engine without an aftertreatment device. The objective of this study is to find out soot and NO removal characteristics focused on the emissions of a Diesel engine by using nonthermal plasma for each engine speeds and loads. Electrostatic precipitator(wire-to-plate type reactor) is used for soot removal. Radicals generated from outer air and put into a mixing chamber in the end of exhaust line are used for NO removal. Concentration of exhaust emissions is analyzed from the gas analyzer(KaneMay) and FTIR to estimate by-products.

메탄올 개질 연료를 이용한 S.I. 엔진의 성능 및 배기 배출물 특성에 관한 연구

장영준,최승환,하철호,전충환,Jang, Yeong-Jun,Choe, Seung-Hwan,Ha, Cheol-Ho,Jeon, Chung-Hwan 대한기계학회 2001 대한기계학회논문집 Vol.25 No.9

There are many regulation test methods to be related with engine emissions such as CVS-75, D-13, ECE-15 modes and so on. Most of these modes are consisted of lots of transient conditions that have rapid acceleration, deceleration and cranking modes. In this experimental research, the engine characteristics of cranking, accelerating and power output in a S.I. engine were studied to compare with neat gasoline and alternative fuels of M30 (methanol 30%, aromatic series 32%, non-aromatic 38%) and M50 (methanol 50%, aromatic 30%, non-aromatic 20%) for performance and exhaust emissions. The results show that reformulated methanol fuels are better emissions reduction of 15.7% over than that of neat gasoline fuel especially in HC and CO emissions at cranking mode. And the accelerating performances coincide with the results of distillation curve. CO concentration for M50 fuel is varied in a just little for the condition of slow acceleration. At wide-open throttle condition, brake specific energy consumption of reformulated fuels is increased and thermal efficiency is some what lower than that of gasoline fuel.

선회도에 따른 평면 화염 버너의 유동특성

장영준,정용기,전충환,Jang, Yeong-Jun,Jeong, Yong-Gi,Jeon, Chung-Hwan 대한기계학회 2001 대한기계학회논문집 Vol.25 No.7

Burner of Flat Flame type expects the uniform flame distribution and NOx reduction. The characteristics of Flat Flame Burner become different according to swirl number in the burner throat. Experiments were focused on swirl effect by four types of swirler with different swirl numbers (0, 0.26, 0.6 and 1.24). It shows many different flow patterns according to swirl number using PIV(Particle Image Velocimetry) method. The flow of burner with swirler is recirculated by pressure difference between its center and outside. Recirculated air makes stable in flame, and reduced pollutant gas. In case of swirl number 0, main flow passes through axial direction. As swirl number increased, The backward flow develops in the center part of burner and Flow gas recirculates. This is caused by radial flow momentum becomes larger than axial flow by swirled air and the pressure at center drops against surrounding. As swirl number increases, the radial and axial velocity was confirmed to be larger than low swirl numbers. And turbulence intensity have similar pattern. The CTRZ(Central Toroidal Recirculation Zone) is shown evidently when y/D=1 and S=1.24. The boundary-layer between main flow and recirculated flow is shown that the width is seen to be decreased as swirl number increased.

비응축성 기체 존재 시 수직관 외벽에서의 응축 열전달계수 상관식 개발

장영준(Yeong-Jun Jang),최동재(Dong-Jae Choi),김신(Sin Kim),정동욱(Dong Wook Jerng),이연건(Yeon-Gun Lee) 대한기계학회 2018 大韓機械學會論文集B Vol.42 No.3

본 연구에서는 비응축성 기체(공기)가 존재할 때, 10 mm의 직경을 갖는 수직 튜브 외벽에서의 응축 열전달계수를 측정하였다. 압력 2~5 bar, 공기 질량분율 10~75 %의 범위에서 실험을 수행하였다. 응축튜브 직경의 차이가 열전달계수에 미치는 영향을 평가하기 위해 측정 결과를 외경 40 mm의 응축튜브로부터 얻은 Lee의 실험 결과와 비교하였다. 본 연구의 측정결과와 Lee, 그리고 Dehbi의 실험결과를 이용하여 전열관의 직경에 의한 영향을 고려할 수 있는 실험적 상관식을 제안하였다. 제안된 상관식의 검증을 위해 Kawakubo의 실험결과와 예측값을 비교하였고, 평균 표준편차는 약 27 %로 나타났다. In this study, condensation heat transfer coefficients are measured in the presence of noncondensable gas (i.e., air) on a vertical tube with a 10-mm outer diameter. Experiments are conducted at pressures ranging from 2 to 5 bar and an air-mass fraction from 10 to 75 %. The experimental results are compared to the heat transfer coefficients obtained on a 40-mm O.D. tube, researched by Lee et al. Using the consolidated data from this study and Lee"s and Dehbi"s tests, a new empirical correlation for the condensation heat transfer coefficient of an air-steam mixture is developed. The proposed correlation is assessed against Kawakubo"s experimental results, and the mean standard deviation is ~27 %.

강의평가 설문 결과를 이용한 양생기공 교육의 효과 분석

장영준(Yeong Jun Jang),이장원(Jang Won Lee),채한(Han Chae),권영규(Young Kyu Kwon),허광호(Kwang Ho Heo),이금산(Guem San Lee),황의형(Eui Hyoung Hwang) 한의병리학회 2013 동의생리병리학회지 Vol.27 No.4

This research is a questionnaire survey conducted to find out educational improvement by analyzing the propriety and difficulty of therapeutic Qigong education practiced in Korean medicine department. We took survey on students after giving therapeutic Qigong education at Pusan National University School of Korean Medicine in the second semester of the year 2011 and 2012. The number of responders was 103 in total. Reflection of training goal was 8.38±1.34, satisfaction of composition of contents was 8.24±1.36, which showed that the education was informative. Difficulty level was 6.11±1.09, which showed intermediate level. The propriety of education material was 7.64±1.72 and propriety of contents was 7.85±1.52, which all turned out to be appropriate. In case of the propriety of time distribution, intermediate point of 5.58±1.92 was found. The therapeutic Qigong education in Pusan National University School of Korean Medicine was evaluated practical and appropriate by students. However, education period should be modified since it is evaluated to be intermediate level.

해상공사에 투입된 예·부선 용선계약의 문제점과 개선방안에 관한 연구

장영준(Yeong-Jun Jang) 한국항해항만학회 2014 한국항해항만학회지 Vol.38 No.5

In general, a regular charterparty form is used as a charterparty for tugboats which are employed in marine construction and a bareboat charter form is generally used for barge boat charterparty. As the tug-barge charterparty which are currently used do not have a standardised form, contracting parties arbitrarily decide on the terms and conditions of the contract. As a result, provisions of the charterparty usually do not specify in the contract which party bears the burden of liability in case of accident. Furthermore, the terminologies used in the charterparty are different from legal terms of current commercial law which causes confusion. These problems can be solved mostly by clarifying the legal character of the charterparty between the contracting parties and by conforming the terminologies. In addition, endeavour to standardise the contract form must be carried forward at the same time. This research purports to study actual condition of current charterparty for tug-barge ship which are employed to marine construction and to suggest systematic improvement plan. For this purpose, this research focuses on studying cases in which dispute arose due to lack of clarity in the provisions of the contract with regard to which party bears the burden of liability in case of accident. This research also purports to suggest forming the standardised contract terms of the charterparty as one way of solution and examine matters to be attended in writing a standardised form.

해상공사에 투입된 부선의 안전관리 책임에 대한 연구

장영준(Yeong-Jun Jang) 한국항해항만학회 2015 한국항해항만학회지 Vol.39 No.1

At marine construction sites, there are problems with regard to dispute on the responsibility of safety management of chartered barge and its legal issues. In general, demise charter with crew is used for barge charterparty which is committed to the marine construction. Although Chapter 5 of the Korean Commercial Act enact provisions regulating a Time Chargerparty and a Bareboat Charterparty, it is difficult to clarify where the responsibility lies with regard to the safety control of the chartered barge. For this reason, disputes on accountability arise when accident occurs in effect. As a result, parties of the charterparty shift the responsibility on each other and there is increased risk for occurrence of similar accidents. There is no legally required qualification for a head of barge workers who is in charge of barge management. It is not possible to demand the head of barge workers to take charge of tasks which requires professional judgment as a marine technician considering his daily work scope. Furthermore, the barge committed to the marine construction as a form of bareboat charter or equipment charterage is an object which should be managed by safety supervisor of the charterer’s marine construction. The charterer bears a duty to manage the safety of the barge. Therefore, the charterer is generally liable for the damage incurred in the course of using the chartered barge.

밀폐 연소실내의 메탄-공기 예혼합기의 연소 및 라디칼 특성에 관한 연구 (1)

전충환,장영준,Jeon, Chung-Hwan,Jang, Yeong-Jun 대한기계학회 1996 大韓機械學會論文集B Vol.20 No.2

To clarify the effects of equivalence ratio, initial pressure and temperature on the flame propagation and radicals characteristics, a series of the experimental study were conducted in a quiescent methane-air premixture using a constant volume chamber. The development of the flame was visualized following the start of ignition using high speed schlieren photo and radical images by intensified CCD camera. Combustion pressure and ion current were recorded simultaneously according to the experimental conditions which were equivalence ratio with 0.7 to 1.2, initial pressure with 0.08 MPa to 0.40 MPa and initial premixture temperature with 3l3.2K to 403.2K. The results showed that the flame speed by ion current and mass fraction burned by combustion pressure characterized the effects of flame propagation very well. And increased combustion duration due to lean combustion condition that was below equivalence ratio, 0.8 caused cycle variation and decreasing the power of engine.

SCV를 장착한 2밸브 Sl 가시화기관의 연소특성에 관한 연구

정구섭,전충환,장영준,Jeong, Gu-Seop,Jeon, Chung-Hwan,Jang, Yeong-Jun 대한기계학회 2001 大韓機械學會論文集B Vol.25 No.12

This study describes the combustion characteristics under various condition of air excess ratio and ignition timing in a 2-valve SI optically accessible engine with swirl control valve(SCV). It adapted three different types of SCV(open ratio 72.5%, 78%, 59%) to strengthen a swirl flow. Pressure data were acquired using pressure sensor to investigate the effect of swirl flow on combustion, and from these pressure data, IMEP(indicated mean effective pressure) and MFB(mass fraction burnt) were calculated to explain burn rate and flame speed. From acquired flame images, we inspected the flame propagation direction, flame area, and flame centroid. Flame propagation direction showed different tendency between with/without SCV, and flame area with SCV was faster and larger than that of conventional engine. Finally, the representative flame images at each crank angle were acquired by PDF method to verify flame growth process. It is found that strengthened swirl flow is more beneficial for faster and stable combustion.

밀폐 연소실 내의 메탄-공기 예혼합기의 연소 및 라디칼 특성에 관한 연구(II)

최수진,전충환,장영준,Choe, Su-Jin,Jeon, Chung-Hwan,Jang, Yeong-Jun 대한기계학회 1997 大韓機械學會論文集B Vol.21 No.5

In order to evaluate the effects of equivalence ratio, initial pressure and temperature on the laminar flame propagation process, and combustion radicals characteristics, experimental approaches are carried out in methane-air premixture using a constant volume chamber. Local and average radical intensities were measured to determine the time and spatial correlations between each radicals; C $H^{*}$(431 nm), $C_{2}$$^{*}$ (517 nm) and O $H^{*}$(309 nm) . The results are showed that two kinds of equation were proposed for the cases of continuous flame and intermittent flame type to evaluate actual equivalence ratio using relative intensities with each radicals. Both equations were agreed with actual equivalence ratio within 10% errors range. And schlieren photo and CCD image were compared with flame sizes at equivalence ratio 1.0.o 1.0.