• 대한기계학회논문집B
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• 제36권5호
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• pp.553-562
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• 2012

난방, 환기 및 공기조절(HVAC) 기능이 상실된 사고의 경우, 보조급수를 위한 모터-구동 펌프격실의 온도상승을 전산유체역학 분석을 통해 평가하였다. 닫힌 펌프격실의 과도 계산결과, 8 시간 동안 공간-평균된 공기온도는 $60^{\circ}C$ 정도의 상승이 예상된다. 외기 온도 및 외부 온도는 이전 계산결과로부터 초기 $35^{\circ}C$에서 시작하여 서서히 증가한다고 가정하였다. 격실 문이 사고발생 후 약 2, 4, 그리고 6시간 경과 시점에서 열릴 경우, 체적-평균 격실 내가 온도는 약 $4^{\circ}C$의 즉각적인 하강이 나타나며 이후 서서히 온도가 상승하는 장기 거동을 보인다. 전산유체역학을 적용한 현재의 상세 해석결과는 이전의 집중(lumped) 모델을 사용한 보수적인 계산결과에 비해 낮은 격실온도 상승률을 예측한다.

• 설비공학논문집
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• 제15권5호
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• pp.346-351
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• 2003

This paper aims at suggesting design guidelines for a perimeter-less HVAC system that contributes energy savings. Perimeter-less HVAC system is one that relieves difficulties fuck as handling mixing loss, uneven radiative environment, and maintenance and repair. It prevents heat load gained through window and outdoor wall without modifying a previously equipped building skin system. In this paper, we performed several kinds of CFD (computational fluid dynamics) cases through numerical simulation to obtain an optimized perimeter-less design, and then we conducted a large-scale model experiment to see how the push-pull air flow would handle indoor heat to obtain an optimized perimeter-less design.

• 설비공학논문집
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• 제15권11호
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• pp.970-978
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• 2003

This paper aims at suggesting design guidelines for a perimeter-less HVAC system that contributes energy savings. Perimeter-less HVAC system is one that relieves difficulties such as handling mixing loss, uneven radiative environment, and maintenance and repair. It prevents heat load gained through window and outdoor wall without modifying a previously equipped building skin system. In this paper, we conducted a large-scale model experiment to see how the push-pull air flow would handle indoor heat to obtain an optimized perimeter-less design, and then we plan to perform several kinds of CFD (computational fluid dynamics) cases through numerical simulation

• 설비공학논문집
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• 제24권1호
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• pp.23-28
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• 2012

In the present work, numerical analyses of air flow in HVAC duct have been carried out for enhancement of cooling/heating performance. For the analyses, three-dimensional Reynolds-averaged Navier-Stokes equations have been solved with the shear stress transport turbulence model. The numerical results were validated in comparison with the experimental data. Based on the numerical results, the HVAC duct was designed to reduce the pressure loss. The modified duct geometry shows largely reduced pressure drop in comparison with the reference geometry. And, through modified duct shape, the performance of air conditioning has been enhanced.

• 한국소음진동공학회논문집
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• 제26권7호
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• pp.820-826
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• 2016

The acoustic performance estimation formulas for silencers are developed mainly by theoretical or empirical methods. However, the existing formulas are available only for a limited range of silencers. In this paper, the procedures for noise analysis of the silencers are established by comparing analytic results to experimental results. With the proven analysis procedures, impedances of the rectangular silencers for ships are adversely predicted from National Environmental Balancing Bureau (NEBB) data, and with the estimated impedances, insertion loss formulas for large silencers are developed using boundary element method (BEM). The developed formulas can be efficiently used for predicting acoustic performance of the silencers for ships.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2005년도 추계학술발표회
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• pp.614-615
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• 2005

• 한국화재소방학회논문지
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• 제18권4호
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• pp.78-85
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• 2004

본 연구에서 Clean Room 재해사례를 분석하였고, Factory Mutual Property Loss Prevention Data Sheets(FM), Industrial Risk Insurers(IRI), NFPA Code 등의 Clean Room 설계 주요 방화기준에 대하여 비교 분석을 하였다. 그리고 화재시뮬레이션을 통한 위험성 평가를 통해서 화재 시 공조설비의 작동으로 인한 연기산란 현상으로 Clean Room 내의 피해규모가 상상을 초월하는 결과를 얻을 수 있었으며, 또한 스프링클러설비의 작동으로 열온도가 더 낮아지고, 연기의 확산속도를 더 줄여줄 수 있는 것으로 분석되었다. 따라서, Clean Room내의 화재 시 화재감지기에 의해 공조설비를 정지시키고, 스프링클러설비를 설치하는 것이 안전성을 확보하는데 중요한 요소임을 유추하였다. 그러므로 본 연구에서 Clean Room 에 대한 안전성을 확보하는데 기여하고자 한다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 춘계학술대회논문집
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• pp.383-386
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• 2003

This paper deals with transmission loss of 3-dimensional rectangular plenum lined chamber. There are three kinds of rectangular plenum lined chamber: throughflow type, flow-reversal type, and end-in/side-out type. The combination of above three types of rectangular plenum lined chamber is used for the commercial HVAC system and automobile exhaust system. However, the ambiguity and complexity of sound absorbing material property and 3-dimensional property have impeded research. In this paper, the transmission loss of three kinds of rectangular plenum lined chamber is derived and calculated. The effect of increase of sound absorbing material is also considered. Analytical solution is calculated by using the locally-reacting property of sound absorbing material.

• 한국해양공학회지
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• 제33권5호
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• pp.479-485
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• 2019

As exhaust gas systems of ships become more complicated, it is necessary to calculate an accurate pressure loss at their design stage. If the dynamic loss coefficients of non-standard fittings mainly used in exhaust gas pipe (EGP) are well-documented, it would be possible to calculate precise pressure loss more readily than using the conventional method that analyzes the entire system. In the case of a ship's EGP, the flow rates and temperatures of exhaust gas are determined by engine specifications, and the range of the flow rate and temperature is limited according to operating conditions. In addition, as it is possible to define non-standard fittings frequently used in an EGP, a database can be easily constructed and effective. This paper illustrates effective parameters and analysis cases of several types of non-standard fittings mounted in ship EGPs. The analysis procedure proposed in this paper is verified using existing research results on HVAC fittings. The numerical procedure, which is minimally affected by manpower and grid, is established such that it can be applied at the industry level.

• International Journal of Railway
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• 제1권3호
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• pp.89-93
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• 2008

Reliability of onboard power supply systems on rolling stock is a very important issue for the railway operator. While a failure of the HVAC supply results in a loss of comfort for the passengers, a failure of the supply for air compressors or for the traction cooling systems results in towing the train. This is, looking at the required availability of a train, not acceptable. An active redundancy concept for the onboard power supply maximizes the availability of the system. This paper describes such a system under the aspect of $\cdot$ Weight reduction $\cdot$ Continuous operation when changing from normal to redundant operation $\cdot$ Flexibility in train design.