• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집A
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• pp.907-912
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• 2001

KOGAS had developed the Ring-knot membrane for LNG storage tank. But we found that some modifications were needed in using the Ring-knot membrane for the commercial LNG storage tanks. So, both analytical and experimental studies have been performed to investigate the strength of the new membrane and the reaction force at the anchor point. Using nonlinear FEM code and experiments, the stress analysis of the new corrugated membrane shapes subject to the cryogenic liquid pressure and thermal loading are performed to ensure the stability and fatigue strength of the new membrane. This paper reports on the results of investigations into this new type of membrane.

• Journal of Welding and Joining
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• 제28권2호
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• pp.27-31
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• 2010

Generally, angle pieces at the corners of cargo tank of membrane type LNG carrier ship are manually welded, due to their various shapes and positions. In this study, a GTA welding robot system was developed in order to improve productivity, which consists of a 7-axis manipulator, a system controller, a GTA welding power source, and peripheral devices. The welding system is characterized by capabilities of welding corrugated work pieces as well as 90/135 degree linear work pieces, and controlling the entire weld cycle automatically. The developed system was field tested on actual work pieces and its performance was proven to be successful.

• 한국포장학회지
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• 제7권1호
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• pp.21-24
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• 2001

This study was carried out to analyze the effects of packaging units and loading types in agricultural products(apple, pear, and sweet persimmon) palletization. In apple and pear packaging, an optimum loading type was pin wheel loading, and load effective corrugated box dimension was $330{\times}220{\times}170mmm(L{\times}W{\times}H)$ in 5 and 10kg packaging units, but in case of pear box was 10mm higher than apple box. However, in sweet persimmon packaging, block loading was available, and box dimension of $365{\times}275{\times}180mm(L{\times}W{\times}H)$ was the most effective to palletize.

• 한국산학기술학회논문지
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• 제21권2호
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• pp.528-534
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• 2020

판형 열교환기의 초기 개발 및 사용은 19세기 후반 유제품 내 존재하던 각종 바이러스의 살균에 대한 엄격한 법규 대응을 위해 시작되었고, 1920년대가 되어서야 본격적으로 상업화되었다. 이후 판형 열교환기의 기본 컨셉은 지금까지도 거의 변화가 없었지만, 고온, 고압 그리고 대용량 열교환에 적용되기 위해 설계 및 제작 방법들이 혁신적으로 발전하여 지금에 이르게 되었다. 현재의 형태와 같은 쉐브론 타입 주름 전열판의 개발은 1970년대 후반 오일 쇼크 이후 에너지 합리화 및 에너지 효율 향상을 위한 요구들이 강하게 제기되면서 시작되어 지금에 이르고 있다. 판형 열교환기의 개발 트렌드는 전열 효율이 좋으면서 압력강하가 낮고 또한 유체 분배가 잘되는 대형 전열판의 개발과 일치한다. 본 논문에서는 전열판 개발방향을 제시하고자 동일 골깊이와 주름피치를 가진 소형 전열판과 대형 전열판의 열성능을 각 채널(H, M, L type)별로 실험적으로 비교, 분석하였다. 실험결과, 대류열전달계수의 경우, 소형 전열판이 대형 전열판에 비해 H type의 경우 평균 16.5%, M type의 경우 25%, 그리고 L type의 경우 약 40% 정도 더 높았다. 압력강하의 경우는 소형 전열판이 H type의 경우 평균 19%, M type의 경우 46%, 그리고 L type의 경우 약 61% 정도 더 높은 것을 알 수 있었다. 이는 여러 예상되는 요인들 중 두 전열판의 유체분배부 차이에 의한 것으로 판단되었다.

• 한국인터넷방송통신학회논문지
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• 제15권2호
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• pp.195-202
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• 2015

위성통신 서비스가 점점 증가함에 따라 단일대역 안테나의 성능을 넘어서는 이중대역 또는 삼중대역 안테나의 필요성도 증가하고 있다. 본 논문에서는 위성통신용 삼중대역 동시사용 안테나를 제안한다. 교체형 혼을 통해 삼중대역을 구현하는 일반적인 다중대역 안테나와는 달리 주름형 혼과 유전체 혼으로 구성된 삼중대역 급전부 조립체 및 그레고리안 타입의 반사판을 사용하여 삼중대역(X, Ku, Ka대역) 신호의 동시 송수신을 가능하게 한다. 제안된 안테나의 특성은 모의실험과 실제측정으로 비교 분석하였다. 그 결과, 제안된 삼중대역 안테나의 방사패턴은 모의실험 계산결과와 비슷한 성능을 보였고, 규격 또한 만족하였다.

• 한국전산유체공학회지
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• 제19권1호
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• pp.47-56
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• 2014

Since a typical plate heat exchanger is made up of a huge number of unitary cells, it may be impossible to predict the aero-thermal performance of the full scale heat exchanger through three-dimensional numerical simulation due to the enormous amount of computing resources and time required. In the present study, a simple flow-network model using the friction factor correlation and a thermal-network model based on the effectiveness-number of transfer units (${\varepsilon}$-NTU) method has been developed. The complicated flow pattern inside the cross-corrugated heat exchanger has been modeled into flow and thermal networks. Using this model, the heat transfer between neighboring streams can be considered, and the pressure drop and the heat transfer rate of full-scale heat exchanger matrix are calculated. In the calculation, the aero-thermal performance of each unitary cell of the heat exchanger matrix was evaluated using correlations of the Fanning friction factor f and the Nusselt number Nu, which were calculated by unitary-cell CFD model.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2011년도 춘계학술발표대회 논문집
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• pp.74-79
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• 2011

This study was accomplished to evaluate the performance of Multi Effect Distillation(MED) for solar thermal desalination system. It was designed Multi effect distillation with $3m^3/day$ capacity and Shell&Tube type heat exchanger. Also, The effective heat transfer of Shell&Tube heat exchanger was used Cu(90%)-Ni(10%) corrugated tube. The parameters relating to the performance of Multi Effect Distillation are known as hot water flow rate. The experimental conditions for each parameters were $18^{\circ}C$ for sea water inlet temperature, $6m^3/hour$ sea water inlet volume flow rate, $75^{\circ}C$ for hot water inlet temperature, 2.4, 3.6, and $4.8m^3/hour$ for hot water inlet volume flow rate, respectively. The results are as follows, Development for Multi effect distillation was required about 40kW heat and 35kW cooling source to produce $3m^3/day$ of fresh water. And, Performance ratio of Development Multi effect distillation was about 2.0191.

• 한국태양에너지학회 논문집
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• 제31권1호
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• pp.1-7
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• 2011

This study was accomplished to evaluate the performance of Multi Effect Distillation(MED) for solar thermal desalination system. It was designed Multi effect distillation with $3m^3$/day capacity and Shell&Tube type heat exchanger. Also, The effective heat transfer of Shell&Tube heat exchanger was used Cu(90%)-Ni(10%) corrugated tube. The parameters relating to the performance of Multi Effect Distillation are known as hot water flow rate. The experimental conditions for each parameters were $18^{\circ}C$ for sea water inlet temperature, $6m^3$/hour sea water inlet volume flow rate, $75^{\circ}C$ for hot water inlet temperature, 2.4, 3.6, and $4.8\;m^3$/hour for hot water inlet volume flow rate, respectively. The results are as follows, Development for Multi effect distillation was required about 40kW heat and 35kW cooling source to produce $3m^3$/day of fresh water. Based on the results of this study, It makes possible to secure economics of desalination system with solar energy which is basically needed development of high efficiency fresh water generator.

• 한국수의병리학회:학술대회논문집
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• 한국수의병리학회 2001년도 추계학술대회 및 정기총회
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• pp.25-25
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• 2001

An example of lymphoblastic lymphosarcoma was diagnosed in a 7-year-old male brown bear (Ursus arctos) that died after having a 7-month history of depression, anorexia and watery diarrhea. Grossly the mesenteric lymph nodes were enlarged to approximately 4 to 6 times their normal size and histologically diagnosed as lymphoblastic lymphosarcoma. The small intestinal mucosa was corrugated and had severe mural thickening due to infiltrated neoplastic cells. Hepatic metastasis was also noted. the mother of this bear which died at the age of 20 also had similar gross changes on necropsy, but histological examination was not performed at that time and therefore the exact type of neoplasm remained to be determined. Since the daughter also died of neoplasm, genetic factor could be suspected in this family. This is the first reported case of lymphosarcoma in Ursidae in Korea. As an incidental finding, endogenous lipid pneumonia was noted in the lung.

• 설비공학논문집
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• 제23권8호
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• pp.535-542
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• 2011

The performance of a plate heat exchanger for using liquid solution in the absorption chiller-heater was analyzed. The model was developed by using the various performance prediction correlations. The performance characteristics of the plate heat exchanger with the mass flow rate ratio was verified by using experimental data. To investigate performance of plate heat exchanger with geometry variables, the chevron angle, corrugated wave length, and corrugation depth were changed. As a result, the capacity of Kim and Martin correlation models was similar with the experimental data, and the capacity difference was less than 2%. Besides, the pressure drop of Marin correlation model showed a similar variation with experimental data, and the difference of pressure drop was less than 1.5 kPa.