• 한국해양환경ㆍ에너지학회지
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• 제6권4호
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• pp.52-66
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• 2003

본 연구에서는 물리, 기계적인 누유 제거방법으로서 부착식의 일종인 드럼식 유회수기를 사용하여 회수조건의 변화에 따른 유회수율을 실험적으로 구하였다. 일반적으로 기계적인 유회수방법에서 문제시되는 것은 고점도 유체에서 유회수가 어렵고, 얇은 유막층에서 회수유중물의 함량이 증가하며, 유회수율이 크게 감소되는 점이다 본 연구에서는 드럼식 유회수기를 이용하여 드럼의 잠긴 깊이에 따른 접촉각, 이송속도, 유막두께 등의 유회수 조건이 유회수율에 미치는 영향을 디젤유를 사용하여 구하고 이를 분석하여 효과적인 유회수 조건을 구하였다. 실험결과 드럼식 유회수기에서 유회수율은 부착유량과 부착유량의 이탈손실에 의하여 영향을 받으며, 부착유량은 잠긴 깊이에 의한 접촉각에 영향을 받는다. 드럼식 유회수기에서의 유회수율은 드럼의 지름에 대한 잠긴 깊이의 비 h/d=0.15(접촉각 45°)에서 가장 효가적인 유회수율을 보이며, 얇은 유막두께에서도 비교적 효과적인 유회수율과 회수효율을 보였다. 또한 이송속도는 최대양정유량을 보이는 임계이송속도를 갖으며, 임계이송속도는 유막두께의 증가에 따라 증가한다.

• 설비공학논문집
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• 제20권9호
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• pp.608-613
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• 2008

The purpose of the present paper is to investigate the effect of outdoor weather conditions on the performance of a heat recovery ventilator. Experiments have been performed by varying outdoor temperature/humidity conditions with the indoor conditions fixed at the standard conditions by KARSE. Results indicate humidity efficiency shows larger uncertainties than temperature efficiency in general. With the heat generation by an internal fan removed, the modified temperature efficiency remains almost constant regardless of the indoor-outdoor temperature difference. The enthalpy efficiency can have very large or negative values in case the outdoor conditions are in the vicinity of the indoor enthalpy line. The direction of heat flow, in such a case, can be opposite to that of moisture flow between two air streams. Discussions are included about various interesting features of the psychrometric processes taking place in a heat recovery ventilator.

• Biotechnology and Bioprocess Engineering:BBE
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• 제11권1호
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• pp.84-87
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• 2006

Batch binding experiments were performed to assess the recovery performance of glyceraldehyde 3-phosphate dehydrogenase (G3PDH) bound to the unshielded and polymer (polyvinyl pyrrolidone. PVP)-shielded dye-ligand (Cibacron Blue 3GA) adsorbent. The adoption of a polymer-shielded, dye-ligand technique facilitated the elution efficiency of bound G3PDH. It was demonstrated that the recovery of G3PDH using polymer-shielded dye-ligand adsorption yielded higher elution efficiency, at 60.5% and a specific activity of 42.3 IU/mg, after a low ionic strength elution (0.15 M NaCl). The unshielded dye-ligand yielded lower elution efficiency. at 6.5% and a specific activity of 10.2 IU/mg.

• 한국자동차공학회논문집
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• 제20권2호
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• pp.21-29
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• 2012

A dual loop waste heat recovery system with Rankine steam cycles for the improvement of fuel efficiency of gasoline vehicles has been investigated. A high temperature loop (HT loop) only recovers the heat of the exhaust gas. A low temperature loop (LT loop) recovers the residual heat from the HT loop, the coolant heat and the remaining exhaust gas heat. The two separate loops are coupled with a heat exchanger. This paper has dealt with a layout of the dual loop system, the review of the working fluids, and the design of the cycle. The design point and the target heat recovery of the HT boiler, a core part of a HT loop, have been presented. The prototype of the HT boiler was evaluated by experiment. For the performance evaluation of the HT boiler, inlet temperature of the HT boiler working fluid was set equal to the temperature degree of sub-cool of $5^{\circ}C$ at the condensing pressure. The exit condition was the degree of super-heat set at $5^{\circ}C$. The characteristics of the HT boiler such as heat recovery and pressure drops of fluids were evaluated with varying flow rates and inlet temperatures of exhaust gas under various evaporating pressure conditions.

• 조명전기설비학회논문지
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• 제21권7호
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• pp.117-123
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• 2007

제조업에서 생산설비에 사용되는 중요한 에너지원 중 하나는 전력에너지이며, 에너지 다소비 업종의 생산설비 즉, 플랜트에서는 사용하는 에너지의 절감과 효율 운전은 매우 중요한 관심사항이다. 본 논문에서는 생산 플랜트의 한 공정에서 가장 빈번히 사용되는 유도전동기를 모델로 하여 실제 진단, 계측을 통하여 측정값을 얻고, 기존의 운전 중인 설비들을 고효율 기기로 교체하였을 경우의 경제성을 분석하였다. 이를 위해서 현재 운전 중인 설비와 고효율설비로 교체하였을 경우에 대하여 각각 설비들의 연간 운전비용과 자본회수계수에 의한 연간 투자비용을 계산하였고, 이를 합산한 연간 총 운용비용을 비교하여 고효율설비의 경제적 타당성을 입증하였다.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 2003년도 추계 학술발표회 논문집
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• pp.299-304
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• 2003

Heat regenerator occupied by regenerative materials improves thermal efficiency of regenerative combustion system through the recovery of sensible heat of exhaust gases. By using one-dimensional two-phase fluid dynamics model, the unsteady thermal flow of regenerators with spherical particles were numerically analyzed to evaluate performance of ratio of waste heat recovery and temperature efficiency and to suggest optimized conditions of heat regenerator. It is predicted that exhaust gases temperature at regenerator outlet of 3.5$\times$10$^{6}$ kcal/hr heat regenerator is even lower than design condition and ratio of waste heat recovery is 75.8％.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.1097-1100
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• 2001

In this paper, the electro-chemical-machining characteristics of Ni-Ti Shape Memory Alloy(SMA) was investigated. From the experimental results, the optimal electro chemical machining conditions for satisfying the machining quality(fine surface & high recovery stress) might be confirmed. And it was concluded that optical electro chemical condition for Ni-Ti SMA could be obtained at approximately 100% current efficiency and high frequency pulse current.

• 한국CDE학회논문집
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• 제17권1호
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• pp.54-61
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• 2012

In this paper, we performed numerical analysis to improve the heat exchange efficiency of wasted heat recovery ventilator which has a delivery and a exhaustion fan. One of the most important design factors that affect the efficiency of heat exchange is uniform counter-flow between inbound and outbound air flows. We had simulated several types of porous plates which were installed at air intake area. With plate having 45 degrees of installation angle and 15 mm diameter holes which are uniformly arranged, we can generate a uniform air flows at the area of porous media where inbound and outbound air flows are cross over. In addition, we installed a duct to reduce vortex flows at the outlet and to discharge exhaust airs rapidly. By using the proposed numerical assessment, we expect the improvement of the heat exchange efficiency of ventilator.

• International Journal of Air-Conditioning and Refrigeration
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• 제13권2호
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• pp.83-88
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• 2005

This study investigates the air leakage and heat transfer characteristics of a commercially available rotary-type air-to-air heat exchanger with a fiber polyester matrix. Crossover leakage between the exhaust and supply air is measured using a tracer gas method for various ventilation rates and rotational speeds of the wheel. A correlation equation for the leakage is obtained by summing up pressure leakage and carryover leakage. The pressure leakage is observed to be a function of ventilation rate only, and the carryover leakage is found to be a linear function of wheel speed. The real efficiency of the heat exchanger can be obtained from its apparent efficiency by taking into account the leakage ratio. The heat recovery efficiency decreases, as the ventilation rate increases. As the wheel speed increases, however, the efficiency increases initially but reaches a constant value for the speeds over 10rpm.

• 전력전자학회논문지
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• 제11권6호
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• pp.529-534
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• 2006

요즘 많은 연구자들이 전력변환회로의 효율을 올리는데 이전보다 훨씬 많은 관심을 기울이고 있다. 플라이백 컨버터에서 RCD 스너버의 저항은 누설인덕터에 저장된 에너지를 소모한다. 이는 전체 시스템 효율을 감소시키는 역할을 한다. 그래서 이 논문에서는 효율을 향상시키기 위해서 플라이백 컨버터의 새로운 에너지 회복회로를 제안한다. 제안된 회로의 동작원리를 자세히 설명한다. 그리고 이를 모의실험 및 실험을 통해서 확인한다.