• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.33 no.8
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• pp.41-47
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• 2004

최근 국내에서도 개별제어를 지향하는 공조시스템의 오피스건물에의 적용이 적극적으로 검토되고 있으며 또 몇몇 실제 적용된 사례가 보고되고 있다. 그 내용을 보면, 바닥취출공조시스템이나 시스템 에어컨이 대부분으로 어떤 의미에서 본격적인 개별공조 (personal air-conditioning system)라고 할 수 없으며, 오히려 실의 공조죠닝을 세분화해 국부적인 재어성을 향상시킨 쾌적성 향상 또는 에너지절약 시스템이라고 할 수 있다. (중략)

• Solar Energy
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• v.19 no.4
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• pp.55-62
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• 1999

This study was performed to find out the influence of experimental factors on dehumidification performance and furthermore to suggest an optimal combination of factors of a total heat exchanger in a solar air conditioning system. The experimental apparatus was set up in a climate-controlled chamber where the temperature and humidity was maintained constant. In order to find out the contribution ratio of factors on dehumidification performance, the table of orthogonal arrays $L_8(2^7)$ was used. According to the results, the most influential factor on dehumidification performance was the concentration of LiCl(Lithium Chloride) solution. The next influential factors were the temperature of LiCl solution and the air flow rate. The packed layer height, packed material, and flow rate of LiCl solution had no influence on the dehumidification performance under these experimental conditions. Through the three level experiments of $L_{27}(3^{13})$, it was found that the optimal combination was $A_2B_0G_2$(concentration of solution 30 wt%, temperature of solution $15^{\circ}C$, air flow rate $253m^3/h$).

• Tribology and Lubricants
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• v.29 no.5
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• pp.310-317
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• 2013

To reduce vehicle fuel consumption due to not only driving but also air conditioning, battery-operated non-starting conditioning systems with thermoelectric modules and without mechanical elements like compressors are being manufactured for use by hybrid heavy trucks in the near future. In this study, the voltage and current consumed by a thermoelectric module were measured to determine the required battery power, and the performance of the conditioning system with air temperature, and humidity of the inlet/outlet modules and inside/outside the cabin for a truck, was evaluated using experimental apparatus under actual conditions. The results showed that, the thermoelectric module can be continously operated for about 1.5 h using existing 24 V batteries. The coefficent of performance(COP) of the cooling and heating modes was calculated to be an average 0.8-1.32. As expected, the heating performance was 30% more efficient than the cooling performance, which is general characteristic of thermoelectric modules.

• Journal of the Korean Solar Energy Society
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• v.24 no.2
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• pp.25-31
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• 2004

Ventilation through air vent system in a building envelope is expected to be an effective measure to release solar radiation. An external surface of a wall absorbs solar radiation and transfers it to the air in the cavity. The warmed air gets buoyant force. So when openings are provided at the top and bottom of the cavity, the warmed air is released through the top opening and cooler outside air replaces the space in the cavity. This reduces the further heat transmission into the built environment. This natural ventilation effect seems to be steady and strong. So because of the cavity and the openings, the cooling load reduction by natural ventilation is believed to be considerable.

• Journal of the Korean Solar Energy Society
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• v.35 no.5
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• pp.11-19
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• 2015

In this paper, EP-Kalina cycle applying liquid-vapor ejector and motive pump is newly proposed. In this EP-Kalina cycle, the liquid-vapor ejector is used to increase pressure difference between inlet and outlet of the turbine. Also the motive pump enhances the performance of liquid-vapor ejector, resulting in increase of system efficiency of OTEC cycles. The comparison cycles in this study are basic, Kalina, EKalina and EP-Kalina ones. The pump work, net power, APRe, APRc, TPP and system efficiency of each cycle are compared. In case of net power, EP-Kalina cycle is lowest among the cycles due to the application of the motive pump. But, the net power difference of cycles seems to be minor since the pump work of cycles is merely about 1kW, compared to turbine gross power of 20kW. The system efficiency of EP-Kalina cycle shows 3.22%, relatively 44% higher than that of basic OTEC cycle. Therefore, the system efficiency is increased by applying the liquid-vapor ejector and the motive pump. Additional performance analysis is necessary to optimize the proposed EP-Kalina cycle.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.9
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• pp.836-844
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• 2001

For the radiant floor heating system, the possibility of suboptimal prediction control was investigated by computer simulation and experiment. For this study, TRANSYS program was used and an experimental facility consisting of two rooms (3$\times$4.4$\times$2.8m) was built. The facility enabled simultaneous comparison of two different control strategies which implemented in a separate room. Results showed that outdoor air temperature prediction control was superior to the conventional outdoor air temperature compensation control for radiant floor heating system. However, more research for fine prediction of outside air temperature was required in the future.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.6
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• pp.89-95
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• 2014

This study presented the benefit of the pre-ventilation using solar sunroof with integrated photovoltaic. Recent year, auto-makers make an effort to enhance the fuel efficiency and moreover to clean the cabin passenger's health. Solar energy, one of the alternative energies, adapted in automotive air handling system, in order to pre-ventilation when vehicle parked under the sun in summer. The power generated by a prototype solar sunroof has been used to run blower in a air handing system. And the solar sunroof was installed in a vehicle, and evaluated to find out benefit of the pre-ventilation. The effect of reducing the cabin temperature about $3^{\circ}C{\sim}10^{\circ}C$ with 20 ~ 40W power generator from solar sunroof were obtained in the pre-ventilation test. This reduced thermal load can lead to the reduction of air-conditioning operation time than that of current car. Moreover, fuel economy may increase as a results of the short use of the air-conditioning time. Additionally, Total Volatile Organic Compounds in the cabin is reduced maximum 80% than that of the current vehicle.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.10
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• pp.718-723
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• 2012

The purpose of this study is to propose modeling method of Underfloor Air Distribution System with reliability and validity by comparing characteristics of modeling methods. For this, the modeling methods of UFAD were selected by investigating various modeling methods of previous researches. Then, simulations were conducted by using EnergyPlus which is dynamic analysis program of building energy. Annual energy consumption for each method was compared with a wide range of indoor thermal loads. As a result, the methodology of reducing internal gains can cause under sizing of the system. It suggests modeling methods to reflect occupied zone air-conditioning, temperature stratification and supply plenum which are the main characteristics of UFAD.

• Journal of Drive and Control
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• v.10 no.2
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• pp.23-29
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• 2013

The excavator is used in a variety of construction environments. There are many kinds of risk like falling rocks or harmful dust. The excavator cabin protects the operator not only from these harmful environments but also provides a comfortable working environment. By the way, the excavator cabin consumes a lot of energy for cabin air conditioner. For this reason, the research is required to reduce energy consumption. This study suggests the air conditioning system for excavator using forced exhaust. First, the forced exhaust system simulated by AMESim tool and surveyed the applicability. Using AMESim simulation, it was investigated the effect of cabin inside temperature by intake flow rate and intake air temperature. The experiment executed using the 1.5 ton excavator and field tested according to the intake flow rate. Finally, verified the applicability on the air conditioning system for excavator using forced exhaust.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.2
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• pp.137-143
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• 2003

In the forming of an integrated system of radiant floor cooling and dehumidifying, chilled coil can be used for cooling and dehumidification. Therefore, it is necessary to find the efficient control method which can eliminates latent load efficiently. This study has been conducted to find this method by dividing the dehumidification system into 3 types according to the control variables and analyzing characteristics of each system. To prevent the floor surface condensation, the amount of condensation can be manipulated by water temperatures, water flow rates in chilled coil, and air flow rates passing by it. So dehumidification system control can be divided into constant air flow control and variable air flow control. Regarding dehumidification control, variable air flow control, which eliminates latent load rather than sensible load, is preferable to constant flow control.