• Journal of Energy Engineering
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• v.22 no.2
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• pp.120-127
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• 2013

This study investigated the characteristics of heat transfer and pressure drop for cross-flow heat exchanger of premixed combustion system. The premixed burner was in front of a heat exchanger, and the number of heat exchanger modules was changed to investigate the characteristics of NOx and CO emissions with various equivalence ratios. In addition, the effectiveness, entropy generation and pressure drop were calculated by various number of heat exchanger modules and the performance of heat exchanger was analyzed by the exergy loss.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.3 no.3
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• pp.183-192
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• 2005

Natural ventilation in radioactive waste repositories is considered to be less efficient than mechanically forced ventilation for the repository working environment and hygiene & safety of the public at large, for example, controlling the exposure of airborne radioactive particulate matter. It is, however, considered to play an important role and may be fairly efficient for maintaining environmental conditions of the repository over the duration of its lifetime, for example, moisture content and radon (Rn) gas elimination in repository. This paper describes the feasibility of using natural ventilation which can be generated in the repository itself, depending on the conditions of the natural environment during the periods of repository construction and operation. Evidences from natural cave analogues, actual measurements of natural ventilation pressures in mountain traffic tunnels with vertical shafts, and calculations of airflow rates with given natural ventilation pressures indicate possible benefits from passive ventilation for the prospective Korean radioactive waste repository. Natural ventilation may provide engineers with a cost-efficient method for heat and moisture transfer, and radon (Rn) gas elimination in a radioactive waste repository. The overall thermal performance of the repository may be improved. The dry-out period may be extended, and the seepage flux likely would be decreased.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.502-507
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• 2009

Trend of mechanical ventilation system applied to apartment house is introduced and feasibility study on installation of the individual room control ventilation as energy-saving method is carried out through field experiment. While initial cost of installation for the individual room control ventilation increases, the running cost is lower than the individual household control ventilation due to automatic flow rate control and reduction of fan power, and the management cost also decreases due to extension of use life of components. As the results of field experiment on $115m^2$-type apartment house, the individual room control ventilation could save the amount of 1,459.5Wh/day when compared with the individual room control ventilation

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.2
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• pp.174-182
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• 2012

In previous research, most occupant said that they have not operated ventilation system installed in the house, because of increasing of energy consumption and unconcern of ventilation. Therefore, it is necessary to applied the sensor based demand controlled ventilation for the IAQ(Indoor Air Quality) and improvement of energy efficiency in ventilation strategy. The propose of this study is to present a application method of IR(Infrared) sensor for multi-zone DCV(Demand Controlled Ventilation) in the apartment house. It is possible that IR sensor could be used for DCV, because that could detect the occupant and action. IR sensor based DCV strategies are established to evaluate characteristic of application in the apartment house and simulated by Contam program. As a result, they have some week points though, if they would be applied DCV with optimum strategy, it would be useful to improve IAQ, to reduce energy consumption.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.11
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• pp.1035-1043
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• 2004

For a long road tunnel, a tunnel ventilation system may be used in order to reduce the pollution level below the required level. To control the tunnel pollution level, a closed loop control algorithm may be used. The feedforward prediction algorithm and the cascade control algorithm were developed to regulate the CO level in a tunnel. The feedforward prediction algorithm composed of the traffic estimation algorithm and the CO density prediction algorithm, and the cascade control algorithm composed of the jet fan control algorithm and the air velocity setpoint algorithm. The verification of control algorithms was carried out by dynamic models developed from the actual tunnel data. The simulation results showed that control algorithms developed for this study were effective for the control of the tunnel ventilation system.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.1203-1205
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• 1987

가솔린 엔진용 전자 제어 에뮬레이션 시스템은 엔진의 운전 상태를 알려 주는 각종 센서로 감지한 정보를 A/D변환기를 통해 마이크로프로세서에 입력시키고, 이 정보를 이용하여 운전 상태를 분석한 후 엔진이 푤요로 하는 연료량, 점화시기, 배기가스의 재순환량, 공회전수 등을 전자적으로 제어하여 엔진의 최적제어를 실현시킴으로서 연료소비율 및 배기가스 중 공해물질 함량을 감소시키기 위한 장치이다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.05a
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• pp.184-185
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• 2023

육상의 원격제어자가 선박을 제어할 때 가상의 모형선박이 같이 조종되도록 하여, 운전상태의 확인을 도울수 있도록 하고, 시험운항시 에뮬레이터를 선박에 연결하여 원격운전데이터의 시각적 확인이 될수 있도록 하였다. 또한 이더넷의 디지털데이터가 아날로그로 변환된후 커넥터로 케이블을 연결할수 있도록 하여, 아날로그 인터페이스를 가진 선박의 장비가 제어가 될수 있는 예시를 보여준다.

• Journal of Energy Engineering
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• v.19 no.3
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• pp.177-181
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• 2010

There are various types of heat exchanger by its purpose and usage, but the important thing is making smaller size of heat exchanger with increasing of the performance of heat exchanger. However, when a burner exists in front of a heat exchanger like boiler, the thermal efficiency of heat exchanger is not only important, but the characteristics of pollutant emission should be considered. Therefore, in this study, a circular tube type of heat exchanger in front of premixed burne, which has a shorter of flame length than that of non-premixed burner and can control $NO_x$ and CO emission by adjustment of equivalence ratio, was installed. Consequently, characteristics of $NO_x$ and CO emission and thermal efficiency of heat exchanger were studied with changing distances between tubes and equivalence ratio, experimentally.

• Journal of Korean Tunnelling and Underground Space Association
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• v.13 no.6
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• pp.451-462
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• 2011

The smoke control system plays the most important role in securing evacuation environment when a fire occurs in road tunnels. Smoke control methods in road tunnels are classified into two categories which are longitudinal ventilation system and transverse ventilation system. In this study it is intended to review the characteristics of smoke behavior by performing numerical analysis for calculating the optimal smoke exhaust air volume with scaled-model and simulation when a fire occurs in tunnels in which transverse ventilation is applied, and for obtaining the basic data required for the design of smoke exhaust systems by deriving optimal smoke exhaust operational conditions for various conditions. As a result of this study, when the critical velocity in the tunnel is 1.75 m/s and 2.5 m/s, the optimal smoke exhaust air volume has to be more than $173m^3/s$, $236m^3/s$ for the distance of the smoke moving which can limit the distance to 250 m. In addition, in case of uniform exhaust the generated smoke is effectively taken away if the two exhaust holes near the fire region are opened at the same time.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2003.02a
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• pp.171-176
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• 2003

육계사의 대형화에 따른 최적환경조성의 중요성이 대두되고 있어서, 이에 따른 적합한 시설환경이 더욱 요구되고 있으나 적정환기가 이루어지지 않아 육계의 생산성 향상에 어려움이 많이 있다. 국내 대형육계사내 최적환경제어를 위한 주요환경변수의 기초자료가 매우 부족한 실정이다. 최 등(1999)은 육계사의 대표적인 여러 계사구조에서 온도, 습도, 유해가스농도 및 육계의 체중, SDS 발생율 및 폐사율, 도체이상 발생율 등을 조사하였다 황보 등(2002)은 3(W)$\times$5(L)$\times$3(H)의 무창계사에서 환경요소 중에 온도, 습도, 공기유속을 분석하여 환경효율을 조사하였다. 대부분의 관련연구들의 자료로는 계사내 환경 균일성, 적정성, 안정성 등을 효과적으로 분석하는 것이 어려웠다. (중략)