• The Magazine for Energy Service Companies
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• s.33
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• pp.58-69
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• 2005

에너지관리공단은 지난 3월 28일 ''소형열병합발전시스템 ESCO사업 투자사업 표준화(안) 공청회''를 개최했다. 이(안)은 기존 소형열병합발전 ESCO사업이 시공사별로 설계 및 설치범위가 다른데다 절감량 산출근거와 방법이 상이해 소비자 혼란과 ESCO간의 과열경쟁으로 치닫는 점을 보완하기 위해서 마련됐다. 공청회 결과를 토대로 표준화 안이 최종 확정될 예정이며 이 자료는(안)임을 밝혀둔다.

• 정보화사회
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• s.157
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• pp.61-66
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• 2002

월드컵을 계기로 부각된 우리나라의 'IT강국 이미지'가 얼마나 지속될 것으로 보느냐는 질문에 대다수(87.0%)의 응답자가 향후 IT에 대한 관심과 투자가 지속된다면 IT강국의 입지가 공고히 될 것으로 응답했다. 그러나 IT 열풍을 일시적인 과열현상으로 보고, 월드컵의 열기가 식으면 IT에 대한 관심도 급속히 냉각될 것이라는 견해도 8.1%로 나와 IT산업에 대한 지원과 투자가 중요한 것으로 나타났다.

• Vending industry
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• v.1 no.4 s.4
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• pp.92-93
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• 2002

최근 2~3년간 부진을 면치 면치 못하는 슬러쉬 시장에 있어 새로운 시장 활성화의 기대를 머금게 하는 신제품이 등장했다. 이 신제품은 슬러쉬를 완전 자동화한 자동판매기 제품으로 신시장 창출 모델로서 큰 기대를 걸게 하고 있다. 그렇다면 과열 새롭게 등장한 슬러쉬자판기가 침체의 슬러쉬 시장에 있다 새로운 활력을 불러일으킬 수 있을까. 금호 집중 취재에서 그 가능성을 집중 취재해 봤다.

• 해운
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• no.8 s.54
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• pp.16-19
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• 2008

중국에서 8월 8일부터 24일까지 2주간에 걸쳐 열린 2008베이징 하계올림픽은 세계 경제대국으로 급부상한 중국의 이미지를 세계에 널리 알림과 동시에 세계 정치, 경제 분야에서의 입지를 더욱 확고히 다져나간 계기가 되었다. 전문가들은 동 올림픽 개최 후 중국 경제에 대해 낙관론과 부정론 입장을 펼치고 있다. 다음은 삼성경제연구소에서 최근 발표한 ‘베이징올림픽 이후 중국경제’를 요약한 것이다.

• Solar Energy
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• v.13 no.2_3
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• pp.53-64
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• 1993

This study investigated heat transfer phenomena during the freezing of an initially superheated or non-superheated liquid in a cooled cylinder tube. Numerical and experimental method were performed to obtatin the temperature and velocity distribution, the shape of interface. Natural convection effects in the superheated liquid were confined and moderated a short freezing time. After natural convection ceases, heat conduction dominated in the whole paraffin, so Crystal and much-zone were found out in PCM. Initial superheating of liquid tended to morderatly diminish the frozen layer thickness at short freezing times but little effect on the these quantities at longer times. On the amount of frozen mass, Iintial liquid superheating is less affected than tube wall subcooling.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.4
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• pp.740-746
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• 2009

Two step serial load induction superheater has been proposed using resonance type induction heat method in this paper. Heat method is a type of flowing the electron induction and current to special alloy heater in body from external heat coil with non-contact method. Inverter was a full bridge serial load resonance type and inductor was used as load in LC resonance design to maximize the efficiency. The developed system is a new heat exchanging method combined with electromagnetic induction heater and fluid movement, ana very accurate to control of heating the gas, liquid and evaporated mass, so on without combustion process.

• Korean Chemical Engineering Research
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• v.52 no.2
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• pp.199-204
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• 2014

In binary solidification compositional convection in a porous mushy layer influences the quality of the final products. We consider the mushy layer solidifying from below with a constant solidification velocity. The disturbance equations for the mushy layer are derived using linear stability theory. The basic-state temperature fields and the distribution of the porosity in the mushy layer are investigated numerically. When the superheat is large, the thickness of the mushy layer is relatively small compared to the thickness of the thermal boundary layer. With decreasing the superheat the critical Rayleigh number based on the thickness of the mushy layer increases and the mushy layer becomes stable to the compositional convection. The critical Rayleigh number obtained from the continuity conditions of temperature and heat flux at the mush-liquid interface is smaller than that from the isothermal condition at the upper boundary of the mushy layer.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.8
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• pp.2012-2021
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• 1995

An experimental study was performed for the analysis of dynamic characteristics of refrigeration system by controlling the evaporator superheat. Experimental data have been taken utilizing two different devices, thermostatic expansion valve(T.E.V.) and electronic expansion valve(E.E.V.), for the control of the evaporator superheat. The ranges of parameters, such as superheat, mass flow rate of refrigerant and inlet temperature of evaporator were 5-30.deg. C 90-170 kg/h and 10-25.deg. C, respectively. The data taken from the T.E.v.and E.E.v.were discussed with the control of the superheat, pressure drop, refrigerating capacity, compression work, evaporating temperature, condensing temperature and COP affecting performance characteristics of refrigeration system. In case of the refrigerant flow control with T.E..V., the superheat and pressure drop of the evaporator varied periodically, but the control with E.E.V., the parameters were very stable. In E.E.v.control, refrigerating capacity, compression work and evaporating temperature were decreased with increasing superheat, and the highest COP was obtained in the range of superheat from 5.deg. C to 15.deg. C.

• Journal of the Korean Society of Propulsion Engineers
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• v.14 no.1
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• pp.20-28
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• 2010

The mixing characteristics of pylon injection in a Scramjet combustor and effects of film cooling to protect pylon from air-heating were investigated. Three-dimensional Navier-Stokes equations with $k-{\omega}$ SST turbulence model were used. Fuel hydrogen and air were considered as coolants. There were remarkable improvements of penetration and mixing rate with the pylon injection. There was also over-heating on the front surface of the pylon without film cooling. The coolant injected parallel to the front surface of the pylon protects the pylon from over-heating.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.6 no.4
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• pp.380-387
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• 1994

An experimental study was performed to investigate the characteristics of refrigerant flow rate control and superheat in an evaporator with an electronic expansion valve(EEV). The EEV used in this study was devised using a needle valve coupled with a stepping motor controlled by a personal computer. A Pill control equation was used to control the superheat of the evaporator and to set the superheat to $5^{\circ}C$. In order to determine an optimum running condition for the system, Pill parameters were varied for the wide range of values. The running condition of an air conditioning system with a PI control was reasonably stable compared with that of the Pill control. Experimental results for the PI control using parameter values, $K_p=1.5$, $T_i=400(sec)$ and $T_s=6(sec)$ show that the superheat reached its target value. When external disturbances were introduced to the system, the superheat target value was reached within about 3 minutes. When the EEV was applied to the air conditioning system driven by an inverter, room temperature control was excellent.