• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2001년도 학술대회 논문집
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• pp.132-135
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• 2001

Cryogenic air separation unit(ASU) was developed about 100 year ago in Europe. However, because there is not any ability of process design or manufacturing of ASU in Korea, many ASUs come from advanced countries every year. The purpose of this study is the development of cryogenic air separation unit by our own ability, especially cold box for nitrogen production. On this study, we developed the computer program for physical properties of gases and process simulation. We also did process design and manufactured of cold box, including air separation column, liquid air heat exchanger and condenser. The result of cold box test was successful.

• 에너지공학
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• 제8권4호
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• pp.533-539
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• 1999

석탄가스화 복합발전 (IGCC ; Integrated Gasification Combined Cycle)에서 가스터빈과 산소분리공간의 연계는 플랜트의 성능과 경제성을 향상시키는 잠재력이 있어 최근에 이에 대한 연구가 다수 수행되었으며, 일부방법은 상용플랜트에 적용이 되고 있다. 본 논문은 가스터빈과 산소분리공정간의 연계방법들에 대해 검토하고 이들 방법을 적용시 IGCC 플랜트 성능을 비교하기위해 Texaco Quench 가스화 공정을 채용한 300MW 급 IGCC를 대상으로 공정모사를 수행하였다. 그 결과, 가스터빈 압축기 출구의 압축공기를 추출하여 산소분리공정에 요구하는 공기의 전량을 공급하는 방법이 가장 플랜트 효율이 좋은 것으로 나타났으며, 플랜트 출력은 산소분리공정의 공기요구량의 75%를 가스터빈에서 추출하여 공급하는 경우에서 최대가 됨을 알수있었다.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2012년도 제45회 KOSCO SYMPOSIUM 초록집
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• pp.49-51
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• 2012

In this paper, the integration issue, such as an air-side integration design between the gas turbine and air separation unit, is described and analyzed by the exergy and energy balance of the combined-cycle power block in an IGCC power plant. The results showed that the net power of the system was almost same, but that of the gas turbine was decreased as the integration degree increased. The highest exergy loss was occurred in the combustor of gas turbine, which was affected by the chemical reaction, heat conduction, mass diffusion, and viscous dissipation.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 추계학술대회 초록집
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• pp.129.2-129.2
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• 2010

As a part of the government renewable energy policy, KOWEPO is constructing 300MW IGCC plant in Taean. IGCC plant consists of gasification block, air separation unit and power block, which performance test is separately conducted. Overall performance test for IGCC plant is peformed to comply with ASME PTC 46. Major factors affected on the overall efficiency for IGCC plant are external conditions, each block performance(gasification, ASU, power block), water/steam integration and air integration. Performance parameters of IGCC plant are cold gas efficiency, oxygen consumption, sensible heat recovery of syngas cooler for gasification block and purity of oxygen, flow amount of oxygen and nitrogen, power consumption for air separation unit and steam/water integration among the each block. The gas turbine capacity applied to the IGCC plant is 20 percent higher than NGCC gas turbine due to the low caloric heating value of syngas, therefor it is possible to utilize air integration between gas turbine and air separation unit to improve overall efficiency of the IGCC plant and there is a little impact on the ambient condition. It is very important to optimize the air integration design with consideration to the optimized integration ratio and the reliable operation. Optimized steam/water integration between power block and gasification block can improve overall efficiency of IGCC plant where the optimized heat recovery from gasification block should be considered. Finally, It is possibile to achieve the target efficiency above 42 percent(HHV, Net) for 300MW Taean IGCC plant by optimized design and integration.

• 한국수소및신에너지학회논문집
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• 제31권3호
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• pp.322-327
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• 2020

In this work, a study for the reduction of the electric power consumption has been estimated in main air compressors in the air separation unit through cryogenic distillation columns with PRO/II with PROVISION V10.2 at AVEVA company. Both required LNG mass flow rate and cold heat contained in 1 ton of LNG were also predicted using Peng-Robinson equation of state with Twu's new alpha function. Through this work, we concluded that 32.33-48.69% of electric power could be saved by using LNG cold heat.

• 한국초전도ㆍ저온공학회논문지
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• 제3권1호
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• pp.69-73
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• 2001

For developing the cryogenic air separation unit, it requires some technology such as basic process design. equipment design and manufacturing based on the cryogenic physical properties and separation theory. In this study, we developed a process and equipment for producing high purity nitrogen which has the production capacity of 1600N㎥/h under 1 ppm $O_2$ and $H_2O$. Also we found that the number of theoretical plate(NTP) of distillation column was 44 and maximum nitrogen recovery ration of this process was 42% from the process simulation. The performance test was also carried out for the nitrogen recovery ratio and equipment efficiency. The results showed that the optimum nitrogen recovery was 41% and the maximum equipment efficiency was attained.

• KEPCO Journal on Electric Power and Energy
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• 제5권3호
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• pp.173-179
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• 2019

심랭식 공기분리공정은 공기를 액화시켜 질소와 산소, 아르곤 등 다양한 산업가스를 생산하며, 가스생산조건(순도, 종류)에 따라 공정 또한 달라진다. 그 중 SNG 플랜트 공급용 공기분리공정은 99.5% 이상의 초고순도 산소 생산을 요구하기 때문에 공정의 효율이 타 공기분리공정에 비해 떨어지며, 공정효율을 낮추는 요인에는 공기압축에 의한 소모동력이 대표적이다. 본 연구에서는 SNG 플랜트에 적용하는 공기분리공정의 에너지 효율 향상을 위하여 소모동력과 관련된 공기 압축 설비의 민감도 분석을 수행하였다. 민감도 분석을 위해 ASPEN PLUS를 이용해 공기분리공정을 모사하였다. 모사 결과, 99.5% 이상의 산소 18.21 kg/s를 생산하였으며, 33.26 MW의 동력이 소모되었다. 모사된 공정 중 공기압축설비는 주 압축기 1대와 2대의 재 압축기가 있으며, 2대의 재압축기에서의 공기압축비 변화에 따른 고압질소, 저압산소, 저압질소의 유량과 순도에 대한 영향과 공정 내 소모동력 변화에 대해 분석하였다. 분석 결과, 99.5% 산소, 99% 질소(고압), 90% 질소(저압)를 생산하기 위한 최적의 운전조건은 재압축비가 각각 0.48, 0.50가 되었으며, 재압축비 조정 후 $0.507kWh/O_2kg$에서 $0.473kWh/O_2kg$으로 소모동력도 약 7%가량 줄었음을 확인하였다.

• Journal of Biosystems Engineering
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• 제13권3호
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• pp.32-43
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• 1988

This study was attempted to investigate the pneumatic separation on separating unit of a combine harvester. The aerodynamic characteristics of threshed materials were analyzed by experiments. The air velocity distribution within the separation chamber was measured for various speeds of the winnower and suction fans to find out the operational and design conditions of the separating unit which would serve for reducing the grain loss from chaff outlet. The results of study arc summarized as follows: 1. Based on the separation curve of threshed materials analyzed, it was shown that three different kind. of materials-kernels, straw chaff, and leaf chaff were as a whole able to be separated pneumatically, regardless of varieties. However, a small amount of the separation grain loss may be expected to occur if the complete separation between kernels and straw chaff would be undertaken because some portion of their separation curve were overlapping. 2. The analysis of air velocity distribution showed that the separation chamber may be divided into two regions, the discharging and separating. The air velocity of the discharging region was 5-15 m/s and that of the separating region 2-5 m/s. 3. The air movement of the separation chamber may be a turbulence flow, being its speed became greater as it moves from the left to the right section of the separation chamber. The equi-speed line. of air flow had a steep gradient in between the discharging and the separation regions. The air velocity in the discharging region was much higher than the terminal velocity of kernels, because of which those kernels appearing in the region could be possibly exhausted as the grain loss from the chaff outlet. 4. The motion trajectory of threshed material in the separating region was dominantly affected by the winnower fan, on the other hand, its motion in the discharging region was affected by suction fan. 5. The grain loss from the chaff outlet was affected greatly by the winnower fan and the trace of kernel movement. It was observed that the optimum working speed to give minimum grain loss from chaff outlet for the combine tested should be maintained at 950~1,150 rpm for the winnower fan and 1,850 rpm for the suction fan. 6. It was shown that a large portion of grain loss from chaff outlet may occur when the kernels may bump against a portion of separation chamber wall and those kernels thus scattered into the discharging region were sucked by the suction fan. It was accordingly recommended that a new design of the wall of separation chamber so as to bump down kernels may be necessary to reduce grain loss from the chaff outlet.

• 한국수소및신에너지학회논문집
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• 제30권3호
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• pp.276-281
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• 2019

The process of separating oxygen and nitrogen from the air is mainly performed by electric liquefaction, which consumes a lot of electricity, resulting in higher operating costs. On the other hand, when used for cold energy of LNG, electric power can be reduced compared to the electric Linde cycle. Currently, LNG cold energy is used in the cold refrigeration warehouse, separation of air-liquefaction, and LNG cold energy generation in Japan. In this study, the system using LNG cold energy and the Linde cycle process system were simulated by PRO/II simulators, respectively, to cool the elevated air temperature from the compressor to about $-183^{\circ}C$ in the air liquefaction separation process. The required amount of electricity was compared with the latent heat utilization fraction of LNG, the LNG supply pressure, and the LNG cold energy usage. At the air flow rate of $17,600m^3/h$, the power source unit of the Linde cycle system was $0.77kWh/m^3$, compared with $0.3kWh/m^3$.

• 상하수도학회지
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• 제20권4호
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• pp.501-507
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• 2006

Dissolved air flotation (DAF) has been well known for the gravity separation process. The solids to be separated are transferred from the water body to the water surface using micro-air bubbles. DAF has also been used for enhancing solids-liquid separation of industrial and municipal wastewater by adding a its unit parallel to a sedimentation unit to reduce the hydraulic loading in the sedimentation clarifier. This study was to investigate flotation characteristics of activated sludge by the recent DAF technique without chemical agents. In addition, the effect on temperature in flotation of activated sludge and the thickening degree of activated sludge were studied.