• Solar Energy
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• v.18 no.4
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• pp.23-32
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• 1998

Fuel cells supply electric power and heat at work, and their exhaust gas is comparatively clear. So they are in the limelight as one of the co-generation systems which behave friendly with the environment. Fuel cells discharge both steam and hot water. Accordingly, if we combine absorption heat pump driven by waste heat with fuel cells, we can construct an advanced energy conserving system. The purpose of this study is the objective for evaluating the possibilities of effectively utilizing waste heat of fuel cells as a heat source for the single and double effect absorption systems. Simulation studies on single and double effect absorption have been performed for water/lithium-bromide pair. The effectiveness of introducing a waste heat source of fuel cells is demonstrated. The result of this study showed that total efficiency was about 85% at rated operation and about 75% at 75% load operation. Absorption cycle moved to more strong concentration when fuel cell operated at 75% load.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.52 no.1
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• pp.12-18
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• 2003

Recently the research for utilization of waste heat produced from electric power plants, casting factories, heat treating factories or commercial building are being afforded by the need for energy saving. The objective of this study is to develop a thermoelectric generation system which converts unused energy from close-at-hand sources such as garbage incineration heat and industrial exhaust etc. into electricity. This paper presents a thermoelectric technology on a optimum system design method and efficiency and cost effective thermoelectric element on order to extract the maximum power output from energy conversion of waste energy. It is shown that the longitudinal stresses of module contacted with two point constrained AI tubes could be released more than those with a one-point constrained.

• Journal of the Korean Society of Combustion
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• v.1 no.2
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• pp.1-7
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• 1996

A recuperative, burner in the capacity of 400kW was designed using the design data from the experimental results. Performance tests on this burner were made. The exhaust gas analysis, including NOx, the measurement of the flame temperature and velocity in the recuperative burner were the main topics of hot combustion tests. Design data from the experimental results are the gas velocity, air velocity, the tip location of gas nozzle and the dimension of furnace. In view of uniform temperature distribution and thermal efficiency, it is appropriate to maintain the furnace pressure at 2-3mmAq.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.2
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• pp.81-91
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• 2000

Dynamic models of line regulator valve(LRV) and ratio control valve (RCV) are obtained for an electronic controlled CVT. LRV and RCV are operated by variable force solenoid(VFS). Considering the CVT shift dynamics, oil pump's efficiency and saturation characteristics of VFS, simulations are performed and compared with test results. Simulation results are in good agreement with the experiments, which shows the validity of the dynamic models of LRV and RCV obtained. In addition, the effects of the orifice size in the exhaust port of RCV are investigated. Simulation results show that as the orifice size decreases, the residual pressure in the primary actuator increases which insures the large torque transmission capacity, meanwhile the duration time for the downshift increases.

• International Journal of Automotive Technology
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• v.8 no.5
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• pp.533-542
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• 2007

The two stroke spark ignition engine is the greatest contributor of the total vehicular pollution in a country like India. It is therefore an item that requires great attention in order to reduce fuel consumption and its concomitant pollution. The use of strong magnetic charge in the fuel line gives a complete and clean burn so that power is increased while operating expenses are reduced. The magnetic flux on the fuel line dramatically reduces harmful exhaust emissions while increasing mileage, thereby saving money and improving engine performance. It increases combustion efficiency and provides higher-octane performance. The experimental results show that the magnetic flux on fuel reduces the carbon monoxide emission up to 13% in a base engine, 23% in a copper-coated engine and 29% in a zirconia-coated engine.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.11
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• pp.883-889
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• 2014

Mufflers have been widely used in the exhaust system to reduce the noise. However, installing muffler may deteriorate the efficiency due to the increase of back pressure. Mufflers usually consist of partition plates and perforated holes in a expansion chamber. In this paper, the influences of the location of the partition and hole on the acoustic TL and back pressure were examined. The acoustic TL was predicted using virtual lab commercial software, while the back pressure were predicted using CFX commercial software. The results were used to set up a database for finding their trends. The optimal muffler model in user-interested frequency range could be selected by analyzing this database.

• Journal of Mechanical Science and Technology
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• v.19 no.12
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• pp.2321-2329
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• 2005

One means of fulfilling $CO_2$ emission legislation is to downsize engines by boosting their power using turbochargers or mechanical superchargers. This reduces fuel consumption by decreasing the engine displacement. When a turbocharger, which is preferable to a mechanical supercharger in terms of fuel efficiency, is used, there is insufficient availability of exhaust gas energy at low engine speeds, resulting in an unfavorable engine response. Therefore, mechanically driven superchargers have increased in popularity due to their quick response to changing speeds in the transient phase. However, since a mechanical supercharger obtains its driving power from the engine, it is difficult to decrease its fuel consumption. This remains a large negative factor for superchargers, despite their excellent dynamic performance. This study aims to develop a power control concept to improve the fuel economy of a mechanical screw supercharger, which could then be used for engine downsizing.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1853-1859
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• 2008

A lot of efforts are inclined by concluding the Kyoto Protocol in Japan for the exhaust decreasing of the $CO_2$ gas in 1997. The Japan Ministry of Land, Infrastructure, Transport and Tourism is promoting various policies through various policies such as `new synthesis logistics policy', 'green logistic partnership meeting', establishment of 'logistics efficiency law' etc. The modal shift case that the individual logistic company in Japan was promoting under such a policy was analyzed in this research, and a modal shift on the distribution site was very promoted, and applicability in our country was examined through the instruction point to this in the future.

• International Journal of Air-Conditioning and Refrigeration
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• v.9 no.4
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• pp.1-9
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• 2001

The temperature and moisture distributions in a dry room with a heat and moisture source -i.e., workers- are studied numerically by using a standard $k-\varepsilon$ turbulence model. In order to evaluate the effectiveness of heat and moisture ventilation inside the room, the heat removal capacity and the moisture exhaust efficiency are introduced. The effectiveness of ventilation control is analyzed by evaluating the temperature and humidity distributions in the room quantitatively. It is found that the mean absolute humidity inside the room is almost constant regardless of the models and the heat generation rates in this study range. This results from the fact that the moisture generation by the workers was relatively small. Through the modification of the design, 40% improvement in critical decay time was achieved.

• Journal of Environmental Science International
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• v.30 no.11
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• pp.967-977
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• 2021

From January 1, 2020, the International Maritime Organization has implemented a global regulation, known as IMO 2020, to reduce the sulfur content in fuel oil of ships from 3.5% to 0.5%. In this study, we used data from air monitoring stations to evaluate the change in air quality at New Port and North Port in Korea areas after the regulation was implemented. The concentration of SO₂ and NO₂ was higher in the port areas than in the surrounding areas due to exhaust gas from ships and vehicles. However, the SO₂ concentration decreased by more than 50% in the port area, demonstrating the efficiency and positive effect of the IMO 2020 sulfur limit.