세라믹 볼 축열체를 이용한 순산소 축열연소시스템에 대한 실험적 연구

홍성국,노동순,이은경,Hong, Sung Kook,Noh, Dong Soon,Lee, Eun Kyung 한국에너지학회 2013 에너지공학 Vol.22 No.2

An experimental study has been conducted for the design of the regenerative oxy-fuel combustion system with ceramic ball. Various design parameters are considered such as ball size, regenerator weight, and combustion load. Regenerative system with a pair of oxygen burners and regenerators is set up and the temperature of oxygen and exhaust gas passing through ball regenerator is measured. It is shown that the temperature distributions with time are affected by ball diameter and regenerator weight, and the significant temperature change is observed by combustion load. As the ball size decreases and the regenerator weight increases, the regenerating temperature efficiency increases. It is found that the heat recovery ratio is low despites of high regeneration temperature efficiency. 순산소 축열연소시스템에서 세라믹 볼 축열체 적용에 따른 축열/재생 특성에 관한 실험적 연구를 수행하였다. 설계인자인 볼 직경, 축열체 무게, 연소부하 변동에 따른 축열/재생 특성을 살펴보았다. 양방향 순산소 축열연소시스템 장치를 구성하여 축열체를 통과하는 배가스 및 산소의 온도를 측정하였다. 실험결과, 볼 직경과 축열체 무게 변동에 따라 배가스 및 산소 온도분포의 변화가 나타났으며, 연소부하 변동시 상대적으로 큰 온도분포의 변화가 측정되었다. 볼 직경이 작아지고 축열체 무게가 증가될수록 측정된 재생온도효율은 증가되었다. 한편, 높은 재생온도효율에 비해 열 회수율은 낮게 예측되어 열 회수율을 향상시키기 위해 축열구조 설계 최적화가 필요함을 확인하였다.

북핵체제하 북한의 정책구도와 개혁·개방

홍성국(Hong, Sung-kook) 북한학회 2008 북한학보 Vol.33 No.2

북한체제는 정치와 경제가 일체화된 체제이다. 그리고 북한에서 핵문제는 정치의 중심에 있으므로 경제문제는 서로 독립적일 수 없으며 서로 밀접한 연관성을 갖는다. 말하자면 북한 체제 유지와 관련하여 북핵문제의 뒤편에 북한의 심각한 경제문제가 자리 잡고 있다. 따라서 북핵체제는 구조적으로 북한의 개혁·개방에 일정한 영향을 미치게 되어 있다. 지금까지 북한의 개혁·개방 조치는 엄밀히 말해 '사회주의적 개선조치'에 머물고 있어 확산되지 못하고 있는 실정이다. 북한의 대표적인 개혁조치라고 할 수 있는 7·1조치의 경우도 이완된 사회주의 질서 회복을 위한 여과적 정책수단으로서 단행된 것이다. 또한 핵체제를 통해 북한이 체제의 내구력을 증대시키기도 어렵다. 핵협상을 통해 외부로부터 얻은 정치경제적 실리는 일시적이거나 허울 좋은 결실일 뿐이며 많은 경우 경제적 희생을 지불해야만 한다. 북핵체제는 일시적인 정권연장효과는 있을지언정 북한이 희망하는 체제보장효과를 기대할 수는 없는 것이다. 이러한 관점에서 '비핵·개방·3000'에서 비핵과 개방은 상호 충돌되는 것이 아니라 북한의 비핵이 개방을 촉진하는 핵심적 요소가 된다고 할 것이다. 또한 건전한 남북협력 문화를 창출하는 기제로 기능할 수도 있다. 우리는 이제 반성적인 차원에서 지금까지의 남북관계가 '남북관계 개선 지상주의'가 낳은 비뚤어진 기형적 소산물임을 냉정하게 되돌아 볼 필요가 있는 것이다. The nuclear issue of North Korea, which includes strongly the political characteristics, can not be separated from economic sectors in North Korea And it also is closely connected with the maintenance of North Korean regume and influences on the probable changes and future directions of North Korea The strong nuclear issue may bring up a weak changes of North Korea Exactly, the reform and opening of North Korea has been nothing but socialist betterment until now The 'July 1st' measures, which is a case of typical measures for economic management of North Korea, was just carried out to recover from its socialist disorders due to economic difficulties North Korea did not tried it to accept market economy or capitalism at all North Korea sticks to the principle of "Our Way of Socialism" and intentionally refuses reform and opening Therefore it is hard to expect that North Korea will try to reform and open the closed system Its reform and opening may be expected only after North Korea gives up its nuclear ambition

전기로 철 스크랩 예열특성에 관한 수치해석적 연구

홍성국(Sung Kook Hong),김승곤(Seung Gon Kim),오정석(Jeong Seog Oh),곽영태(Young Tae Quahk),이은경(Eun Kyung Lee),고창복(Chang Bog Ko),이대근(De Keun Lee),노동순(Dong Soon Noh) 대한기계학회 2016 대한기계학회 춘추학술대회 Vol.2016 No.4

수성전이반응을 포함한 수증기 개질시스템에 대한 수치해석적 연구

홍성국(Sung Kook Hong),동상근(Sang Keun Dong),한정옥(Sang Keun Dong),이영철(Young Chul Lee),이중성(Joong Seong Lee) 대한기계학회 2013 대한기계학회 춘추학술대회 Vol.2013 No.5

메탈화이버 연소기를 이용한 수증기 개질반응기에 대한 수치해석 연구

홍성국(Sung Kook Hong),동상근(Sang Keun Dong) 대한기계학회 2013 대한기계학회 춘추학술대회 Vol.2013 No.12

The numerical investigation is performed to gain the insight for optimal design of 300 Nm<SUP>3</SUP>/hr steam reforming reactor. It is assumed that three metal fiber burners are installed in the reactor with the 20 reforming tubes for delivering the required reaction heat. In this study, the design parameters of metal fiber burner are considered such as the secondary air flow rate and the input heat. The commercial program is utilized for the heat and flow calculation which are coupled with steam reforming reaction. Through numerical calculation, the characteristics on reforming rector are evaluated according to various design parameters. It is found that the temperature distributions in the reactor and the amount of produced reforming gases significantly varied depending on the secondary air flow rate of metal fiber burner.

가스터빈 연소실 냉각을 위한 충돌제트 / 유출냉각기법에서 사각핀 설치에 따른 열/물질전달 특성

홍성국(Sung Kook Hong),이동호(Dong-Ho Rhee),조형희(Hyung Hee Cho) 한국유체기계학회 2004 유체기계 연구개발 발표회 논문집 Vol.- No.-

The present study has been performed to investigate the influences of rectangular fins on heat transfer in an impingement/effusion cooling system with crossflow. To simulate the impingement / effusion cooling system with initial crossflow, two perforated plates are placed in parallel and staggered arrangements with a gap distance of 2 times of the hole diameter. The crossflow passes between the plates, and various rectangular fins are installed on the plates. Reynolds number based on the hole diameter is fixed to 10,000 and the flow rate of crossflow is changed from 0.5 to 1.5 times of that of the impinging jet. A naphthalene sublimation method is used to obtain the heat/mass transfer coefficients on the effusion plate. Also to analyze the flow characteristics, a numerical calculation is performed. When rectangular fins are installed, the flow and heat transfer pattern is changed greatly from case without fins. In the injection hole region, the jet impinges on effusion plate without deflection and wall jet spreads symmetrically. In the effusion region, the crossflow accelerates due to the decrease of cross-sectional area in the channel. Local heat/mass transfer coefficients are enhanced significantly compared to case without fins. As the blowing ratio increases, the effect of fins against the crossflow becomes more significant and then the higher average heat/mass transfer coefficients are obtained than the case without fins.

충돌제트/유출냉각기법에서 회전효과에 의한 열/물질전달 특성

홍성국(Sung Kook Hong),조형희(Hyung Hee Cho) 대한기계학회 2006 대한기계학회 춘추학술대회 Vol.2006 No.6

The purpose of this study is to investigate the effect of rotation on heat/mass transfer in an impingement/effusion cooling system. To simulate the rotating impingement/effusion system, the test duct with 16 injection holes and 8 effusion holes is installed on the rotating system. Jet Reynolds number based on the hole diameter is fixed to 3,000 and Rotation number is set to 0.032. A naphthalene sublimation method is used to obtain the heat/mass transfer coefficients on the effusion plate. The local distributions of heat/mass transfer coefficient are significantly changed due to the rotation. In the impingement/effusion cases with ±90 stagger angle, low and non-uniform heat/mass transfer distributions occur because the impinging jet is deflected by Coriolis force. It is confirmed that the averaged heat/mass transfer value of impingement/effusion is higher than that of array jet in both the rotating and the stationary conditions.

회전하는 충돌제트/유출냉각기법에서 분사홀 변화에 따른 열/물질전달 특성

홍성국(Sung Kook Hong),조형희(Hyung Hee Cho) 한국유체기계학회 2006 유체기계 연구개발 발표회 논문집 Vol.- No.-

The present paper deals with the heat/mass transfer characteristics for rotating impingement/effusion cooling system. For enhancement of the heat/mass transfer, the size and number of injection hole is changed and the effect of variation of injection hole is investigated under the same cooling flow rate. The three ducts with different injection holes are tested and two different jet orientations are considered at the same rotating speed. Reynolds number based on the effusion hole diameter is fixed to 3,330. A naphthalene sublimation method is used to obtain the heat/mass transfer coefficients on the effusion plate. The LH case with injection hole diameter of 10 mm shows that the local heat/mass transfer is significantly varied by rotation. Moreover, low and non-uniform Sh distributions occur because the impinging jet is deflected by Coriolis force. Meanwhile, the DH and SH cases with injection hole diameter of 5 mm change the Sh distributions slightly due to increased jet momentum. Local heat/mass transfer coefficients are enhanced significantly and the rotation effect decreases with increasing the jet velocity. Averaged Sh value rises up to 45%, 85% depending on the variation of injection hole. However, the uniformity of heat/mass transfer deteriorates because of steep variation of heat/mass transfer.

韓國人 正常人 및 消化器疾患患者에 있어서의 D-xylose 吸收에 關한 硏究

洪性國(Sung Kook Hong) 대한외과학회 1971 Annals of Surgical Treatment and Research Vol.13 No.10

분사홀에 설치된 turbulator에 따른 충돌/유출면에서의 열/물질전달 특성

홍성국(Sung Kook Hong),이동현(Dong Hyun Lee),김영도(Young Do Kim),조형희(Hyung Hee Cho) 한국유체기계학회 2007 유체기계 연구개발 발표회 논문집 Vol.- No.-

In order to enhance the heat/mass transfer, a turbulator has been installed at the exit of injection hole for the impingement/effusion cooling system The local heat/mass transfer coefficients have been obtained by a naphthalene sublimation method. Experiments have been carried out at the fixed jet Reynolds number of 10,000. Two turbulators with different diameter have been used in the present study. The result presents that the turbulator leads to the increase in flow mixing and jet velocity, consequently enhancing the heat/mass transfer at a stagnation region. Further, the stagnation region is divided into four small areas with peak value. In the existence of initial crossflow, the stagnation regions move downstream and low heat/mass transfer regions are formed regardless of the installation of turbulator. However, the increased jet velocity by turbulator reduces the crossflow effect against the jet, resulting in decrease of low heat/mass transfer regions. With respect to averaged Sh value, the installation of turbulator yields 5~10% augmentation compared to the case without turbulator.