• 설비공학논문집
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• 제17권9호
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• pp.824-829
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• 2005

MHR(Metal Hydride Refrigerator) powered by MGT exhaust gas is investigated to find out the optimum conditions corresponding to MGT operating powers. There are many factors to affect cooling capacity of MHR. In this study, the effect of switching time, flow rate of brine on cooling temperature and capacity is investigated. The present results show (1) hydrogen reaction is saturated with 25 min switching time at 25 kW MGT power, (2) cooling power shows maximum phenomenon with increasing switching time, (3) optimum switching times are 20 minutes for 15kW MGT power and 15 minutes for 20, 25kW MGT power, (4) according to increasing brine flow rate, cooling capacity shows decrease at 15 kW MGT power and changes little at above 20 kW MGT power.

• 농업과학연구
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• 제19권1호
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• pp.91-96
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• 1992

동력경운기(動力耕耘機) 탑재용(搭載用) 디젤 기관(機關)은 정격출력(定格出力) 범위내(範圍內)에서는 작업시(作業時)에도 냉각수(冷却水) 용량(容量)이 부족(不足)하여 과열(過熱)되고 있다. 따라서, 기관(機關)의 적정(適定)한 냉각수(冷却水) 용량(容量)을 구명(究明)하기 위하여 기존의 기관(機關)에 순경(循璟) 펌프를 설치(設置)하여 냉각수(冷却水) 증가시(增加時)의 성능변화(性能變化)에 대한 실험(實驗)을 실시(實施)하였는데, 그 결과(結果)는 다음과 같다. 1. 동력경운기(動力耕耘機) 탑재용(搭載用) 디젤 기관(機關)의 냉각수(冷却水) 용량(容量)은 정격출력(定格出力) 내(內)에서도 부족(不足)하였다. 2. 기관(機關)에 냉각수(冷却水) 순경(循璟)펌프를 설치(設置)할 경우에 $12{\ell}/min$로 순경(循璟)시키는 것이 적합(適合)하였다. 3. $12{\ell}/min$ 순경시(循璟時) 최고온도(最高溫度)는 $91^{\circ}C$이었으며, 이는 SAE Standard인 $88{\pm}5^{\circ}C$ 이내(以內)였다.

• 설비공학논문집
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• 제9권3호
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• pp.333-342
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• 1997

An experimental study has been carried out to investigate the effects of the combination of the different wire mesh number in a regenerator and the tube number in a cooler on the cooling performance of a Vuilleumier cycle heat pump. Effects of operating conditions, such as charging pressure, operating speed, and heat input, on the cooling performance are also studied. The experimental results obtained indicate that the cooling performance could be improved with the proper combination of different wire meshes in a regenerator. More tubes in a cooler are desirable for better cooling performance. It is also found that the cooling capacity is enhanced, whereas COP is reduced with an increase in the heater tube temperature and the revolution speed. Both the cooling capacity and COP are incereased with a higher charging pressure.

• 설비공학논문집
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• 제15권11호
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• pp.937-942
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• 2003

In the present study, low-temperature low-pressure refrigerant storage method is proposed to achieve higher cooling capacity during a short period of time than that of a compressor in steady operation. Experimental apparatus was designed and set up to analyze the performance of the new-conceptual cooling system. Two reservoirs for sequential storage of refrigerant were used in the cooling system. Several on/off solenoid valves were installed for control of refrigerant flow. From the experimental results, the initial rapid cooling by low temperature low-pressure refrigerant storage method was ascertained for successful operation. This rapid cooling methodology shall be useful for other low-capacity refrigeration system.

• 한국유체기계학회 논문집
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• 제17권6호
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• pp.84-88
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• 2014

A long term passive cooling system is considered as the most important safety feature for the nuclear design after the Fukushima Daiichi nuclear power plant accident in 2011. The conventional active pump driven safety systems are not available during a station Black Out (SBO) accident. The current design requirement on cooling time of the Passive Auxiliarly Feedwater System (PAFS) is about 8 hours only. To meet the 72 hours cooling time, the pool capacity of cooling water tank should be increased as much as 3~4 times larger than that of current water cooling tank. In order to extend the cooling time for 72 hours, a new passive air-water combined cooling system is proposed. This paper provides the feasibility of the combined passive air-water cooling system. The current pool capacity of water cooling system is preserved, and the cooling capability is extended by an additional air cooler.

• 설비공학논문집
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• 제14권3호
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• pp.214-220
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• 2002

A small air conditioner using thermoelectric module has been designed and built. Three types of cooling methods, such as air cooling, closed-loop water cooling, and evaporative cooling, for hot side of thermoelectric module have been investigated. Among three types of cooling method, the evaporative cooling method is seen to be the most effective to achieve the steady state operation of a thermoelectric air conditioner The system performance with evaporative cooling method are also studied in detail for several oprating parameters, such as input power to the thermoelectric module, water or air flow rate at the hot side, and air flow rate at the cold side. The results obtained indicate that the cooling capacity of a system is increased with an increase in the input power to the thermoelectric module while the system COP is decreased. It is also found that the optimal air flow rate as well as water flow rate at the hot side is needed for the best system performance at a liven operating condition. Both the system COP and cooling capacity are increased as the air flow rate at cold side is increased.

• 설비공학논문집
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• 제21권3호
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• pp.149-156
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• 2009

A small-scale thermoelectric cooling system was built in an effort to enhance the performance of the refrigeration system by utilizing the water-cooled jacket which was attached to the hot side of the thermoelectric module. Considered design parameters for the water-cooled jacket were the geometry of the flow passage inside the jacket and the flow rate of cooling water. The higher flow rate of cooling water in the jacket resulted in a better performance of the refrigeration system. The increase in the number of channels for water flow passage inside the cooling jacket also showed significant improvement on the performance of the thermoelectric cooling system such as the cooling capacity and the COP of the refrigeration system.

• 한국자동차공학회논문집
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• 제22권3호
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• pp.60-67
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• 2014

The battery cells in lithium-ion battery pack assembled with high-capacity and high-power pouch cells, are commonly cooled with thin aluminum cooling plates in contact with the cells. For HEV/EV lithium-ion battery systems assembled with high-capacity, high-power pouch cells, the cells are commonly cooled with thin aluminum cooling plates in contact with the cells. Thin aluminum cooling plates are cooled by cold plate with coolant flow paths. In this study, the effect of the battery cooling system design including aluminum cooling plate thickness and various position of cold plate on the cooling performance are investigated by using finite element methods (FEM). Optimal cooling plate and cold plate design are proposed for improving the uniformity in temperature distributions as well as lowering average temperature for the cells with large capacities based on the simulation results.

• 농업과학연구
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• 제33권2호
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• pp.107-114
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• 2006

An all-aluminum radiator made of aluminum was more excellent on environment friendliness, productivity, and cooling efficiency than the plastic tank radiator which was currently widely used in same size as above. A newly designed and manufactured radiator with all parts made of aluminium was ready to re-use without any disassembly process in recycle system so as to improve environment friendliness with low waste cost. Several manufacturing processes of the current plastic tank radiator such as O-ring inserting, and clinching of core to the tank, were eliminated on the manufacturing processes of the all-aluminium radiator, which would increase productivity and reduce production cost. Design criterion of all-aluminum radiator was presented by carrying out theoretical analysis of cooling capacity and there was no difference between analytical data and measurements. Cooling capacity of the all-aluminum radiator increased generally 13% up compared with the plastic radiator even though the pressure drop of air increased.

• 설비공학논문집
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• 제15권6호
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• pp.447-453
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• 2003

The air-side particulate fouling in the heat exchangers of HVAC applications degrades the performance of cooling capacity, pressure drop across a heat exchanger, and indoor air quality. Indoor and outdoor air contaminants foul heat exchangers. The purpose of this study is to investigate the cooling performance and pressure drop on the air-side particulate fouling of heat exchangers for air conditioners. Air conditioners being used in the field such as inn, restaurant, and office are collected in chronological used order. Test results show 15% decrease of the cooling capacity and 44% increase of the pressure drop for the 7 years air conditioners used in the seaside inn.