• 설비공학논문집
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• 제24권11호
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• pp.813-822
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• 2012

In this study, the multizone simulation for biosafety of BSL3 lab. and energy simulation are carried out simultaneously by using linked model of CONTAM and TRNSYS. In BSL3 lab., annual energy consumption is approximately five to ten times more than the magnitude of the office building. This is because required air change rate is extremely large and it is difficult to maintain room pressure difference efficiently. To maintain pressure difference between laboratory rooms through sealing condition of doors and proper airflow control is significant. In this study, to predict indoor environment of the BSL3 lab.(Influenza A research lab.), the multizone simulation for four kinds of biohazard scenario is also performed as part of risk assessment. Multizone and energy simulation results by using linked model show that these approaches are used as a tool for the energy efficient design and operation method for the safer BSL3 lab. facilities.

• 설비공학논문집
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• 제22권10호
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• pp.710-718
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• 2010

A numerical study was performed to predict refrigerant charge amount in a mini-channel condenser for a R410A residential air-conditioning system. Multi-channel flat tubes with 12 mini-channels of 1.17 mm average hydraulic diameter for each tube were applied to the condenser. The condenser consisted of 3 passes, and the first, second, and third pass had 44, 19, and 11 tubes, respectively. Each pass was connected by a vertical header. In this study, the condenser was divided into 410 finite volumes, and analyzed by an $\varepsilon$-NTU method. With thermophysical properties and void fraction models for each volume element, the R410A amount distribution and a total charge amount in the condenser were calculated. The predicted total charge amount was compared with the experimentally measured charge amount under a standard ARI A condition. The developed model could predict the charge amount in the mini-channel condenser within prediction errors from -23.9% to -3.0%. Air velocity distribution at the condenser face was considered as non-uniform and uniform by the simulation model, and its results showed that the air velocity distribution could significantly influence the charge amount and vapor phase distribution in the condenser.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2005년도 하계학술발표대회
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• pp.176-176
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• 2005

• 설비공학논문집
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• 제13권3호
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• pp.217-223
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• 2001

There exist a number of approaches which can evaluate ventilation and indoor air quality. The measurement and analysis of indoor carbon dioxide concentrations can be useful for evaluating indoor air quality and ventilation. This paper describes a numerical analysis of carbon dioxide concentrations for evaluating indoor air quality and ventilation and the factors the need to be considered in their use. The conditions of this numerical analysis are tow types of positions and inlet velocities of ventilation system in a two-dimensional model of an apartment house. The simulation results could be used as a base data for further analysis for ventilation design of other industrial processes producing a proper ventilation system for a healthier and more comfortable environment in a building.

• 설비공학논문집
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• 제14권4호
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• pp.278-284
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• 2002

The work presented here provides a control of the supply duct outlet air temperature in PEM (personal environment module) using fuzzy PID controller. In previous work, PID control systems were used, but the result shows that the outlet air temperature and electric heater regulating voltage were oscillated. Fuzzy PID control systems are designed to improve the system response obtained using PID control and implemented experimentally Also, PID controller and fuzzy controller without PID logic are provided to compare the result with that of the fuzzy PID controller. Data obtained shows that the fuzzy PID control system satisfies the design criteria and works proper1y in controlling the supply air temperature. Also it has bettor performance than the previous result obtained using PID control.

• 설비공학논문집
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• 제13권1호
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• pp.59-65
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• 2001

The work presented here is an implementation of PID control to achieve a required supply air temperature in PEM(Personal environment module). In PEM, the air is heated to the required temperature while it flows through the supply duct, without any mixing chamber. This makes the control of air temperature in PEM difficult. Linear dynamic model of heat transfer in PEM is first obtained. Then P, PD and PID type control systems, to provide the rapid response without overshoot and saturation, are designed and implemented experimentally. Data obtained shows that the control system satisfied the design criteria and works properly in controlling the supply air temperature.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.1443-1448
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• 2009

Numerical analysis has been carried out to investigate air-side convective heat transfer characteristics in compact heat exchangers with continuous plate fins. Simulation results such as air flow and temperature distributions are presented, and heat transfer characteristics are compared for various inlet conditions. Results from various turbulence models are also compared for applicability. There is large difference between the local heat transfer coefficient distributions along the cylinder wall for circular tubes. Colburn j factors from the calculated results of circular and flat tubes in the heat exchangers are compared for various Reynolds number. The predicted results in this study can be applied to the optimal design of air conditioning system. with compact heat exchanger.

• 대한설비공학회지:설비저널
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• 제5권2호
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• pp.91-97
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• 1976

This study was concerned with performance of 2 types of black painted solar air heaters, one is finned type better, the other is mesh type. The performance test of heaters was made under the different operating conditions during winter season of December in Seoul area. It was analized and discussed by comparing the overall efficiency of 2 solar heaters at the same mass flow rate and ambient temperature. Experimental results show that finned type solar heater is better than mesh type from the point of view of design and heat removal efficiency. Finned-type solar air heater supplies hot air up to 30 degree centigrade above ambient temperature with an overall efficiency of 47 percent whilemesh type was 44 percent.

• 설비공학논문집
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• 제25권7호
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• pp.406-412
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• 2013

A hybrid heat pump is under development with the goal of utilizing 120% of primary energy resources. A plate heat exchanger is added between the compressor and air-cooled condenser of an ordinary heat pump to heat water. For successful operation of the heat pump, it is necessary to develop a control algorithm under various operating conditions. As a virtual test bed for that purpose, a dynamic model has been developed, to simulate its dynamic behavior. It was modeled in transient one-dimensions, with varying phase lengths considered. The model was implemented in Matlab and Simulink. Simulation results were effectively applied to design a control algorithm. They also provided physical insight into how to design and operate the system.

• 설비공학논문집
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• 제6권2호
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• pp.93-102
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• 1994

It is the goal of this study to provide the essential data for design and operation of optimum water supply system. Experimental and theoretical analyses have been conducted for various parameters, for example, volume and air percent of pressurizing tank, pump speed and pressure range inside tank, etc. Pressure inside tank with time, flow rate, energy consumption rate and pump operation time have been obtained for design and operating parameters to optimize the components and to establish the operating method of system, and therefore to contribute to the development of technology from a point of view of the improvement of quality, the enhancement of system efficiency and the reduction of construction cost.