• Journal of Digital Convergence
• /
• v.10 no.2
• /
• pp.225-229
• /
• 2012

A reformer for a small fuel cell system is an apparatus which converts hydrocarbon fuel into hydrogen-rich gas. Among many indices of a reformer, the most crucial index of a reformer is CO concentration in the off-gas out of reformer which must be controled under 5ppm for the efficiency and performance of a system. This paper suggests the criteria of a reformer operation for the stability of a reformer in a fuel cell system by deducing crucial indices and improving processes. The six-sigma technique was applied to verify the optimum control and operation of a reformer of a fuel cell combined heat and power system. The result of temperature control of each parts of a reformer system is the concentration of CO which is the most important factor for the operation of a fuel cell system. The temperature of the parts of a reformer, MTS, LTS and Prox, were controled so that the concentration of CO.

• Carbon letters
• /
• v.2 no.2
• /
• pp.113-119
• /
• 2001

The advanced method for $CO_2$capture is currently one of the most important environmental issues in worldwide and it is therefore necessary to have available technologies, which minimize the discharge of $CO_2$ including Carbon-14 from nuclear facilities into the atmosphere. A key aspect of this work is to provide the technically principal data required to improve a $CO_2$ removal system for the utilization of regenerative sorbent use, specifically include suggestions regarding its modified column design (parallel dual-bed assembly), stop-restart operation and the economic feasibility of sorbent use. The removal performance of soda lime and the effects of relative humidity (RH) and packing bed-depth (BD) on $CO_2$ removal were investigated. In a single-bed, it revealed that the utilization of soda lime for $CO_2$ removal at line velocity of 13 cm/sec and bed depth of 12 cm increased with the increased relative humidity up to 85%. However, in the parallel dual-bed assembly applied with the stop-restart operation, a maximum utilization rate of soda lime for $CO_2$ removal was obtained even at 55% of RH and 8 cm of BD, specifically the utilization rate of soda lime by using this $CO_2$ removal assembly was about two-fold superior to that in a single-bed.

• Journal of Korean Library and Information Science Society
• /
• v.9
• /
• pp.85-113
• /
• 1982

The information material in the library or in the information service center is at once its own property and the national resources, so that every citizen in the country has the right to the equal use of it for the development of the country. Library co-operation enables every citizen to use easily and equally the materials in the library. In the informational society of today, owing to the information explosion, the increase in the various user's demand of the information, and the rise of the cost of information material, even the richest and highly advanced country cannot be self-sufficient. Under these circumstances, the international co-operation among libraries seems to be the best way to solve the difficulties of selfsufficiency. Therefore, this paper aims to study the background of IFLA founded in 1927 in order to promote the international library co-operation and its development up to 1970's since its establishment, and, by introducing IFLA's programs of UBC, ISBD, and UAP, to consider the significance of IFLA's contribution to the development of library and librarianship.

• Proceedings of the IEEK Conference
• /
• 2001.10a
• /
• pp.755-758
• /
• 2001

Most of the waste plastics are incinerated and landfilled now, leading to much environmental problems. The technology of injection into the blast furnace was developed as a useful recycling method of waste plastics, and applied to the actual operation in several ironmaking companies. We carried out the test operation to inject continuously the two kinds of waste plastics through four tuyeres of the Foundry blast furnace in POSCO by 130 ton of total amount. From this test operation, we analyzed the coke replacement ratio, the permeability, the heat load and other changes of furnace conditions with the injection of waste plastics into the blast furnace. Some trials based upon the theoretical approaches were applied to examine the efficiencies of blast furnace.

• Proceedings of the KIEE Conference
• /
• 2015.07a
• /
• pp.1157-1158
• /
• 2015

This work is to study the effect of load current on 6.6 kV power cables in operation. In order to figure out the relationship between load current and temperature of the power cables, we have developed measuring equipment for insulation resistance, temperature, and current tested on 9 cables at power station, Western Power Co. Ltd. The cables used in our test were in operation for the last 18 years. Our research over a year showed that the remaining lifetime of 8 cables was more than 20 years. The remaining lifetime of one cable was about 16 to 18 years.

• Proceedings of the KIEE Conference
• /
• 2001.05a
• /
• pp.166-168
• /
• 2001

Generation by the privately owned generators, which are normally operated has occupied about 10% of total generation. Recently the small co-generation employed gas engine has been introduced and attracted public interest. For privately owned generator to be paralleled Utilities, a customer complies with Generator Parallel Operation Guideline set by Utilities and installs related protective relays. But the guideline is not specified to small co-generation, only provides parallel operation of privately owned generator. So applying this guideline, initial investment can be too high comparing to total co-generation cost. Besides there is no specified guide about ALTS, which arises asynchronous problem. In this paper we analyzed guideline and technical problem when small co-generation is paralleled. And additionally needed researching area to improve distribution of small co-generation is discussed.

• Proceedings of the KIEE Conference
• /
• 1994.07b
• /
• pp.1643-1645
• /
• 1994

It has been reported frequently that damage to underground electric power cable was brought about, due to attack by Insect such as termite (white-ant) and by rodent such as rat, in tropical and semitropical areas. Among these cable damages, we are likely to describe the damage to cable by termites as causing the severe trouble in cable operation and to solve this trouble with termite-proof method regarded as the most effective and economical one. This report covers our experiences of manufacturing the cable for anti-termite purpose and its intrinsic properties in cable operation.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2018.11a
• /
• pp.100-101
• /
• 2018

Environmental problems caused by air pollution have been considered as serious critical issues in global perspectives. Controlling greenhouse gases has become one of the major environmental problems in construction fields as well. However, similar studies were mainly focused on suggestion of various methodologies for measuring CO₂ emissions of construction equipment and calculating emissions. This study aims to analyze the correlation between the CO₂ emissions and RPMs of equipment by the construction process based on row data collected from construction equipment actually operated in job sites. This study allows site personnels to determine the amount of emitted CO₂ under particular construction equipment under specific conditions during the targeted construction operations. The research findings expect to be used as fundamental informations for establishing environment-friendly construction operation planning.

• 한국연소학회:학술대회논문집
• /
• 2004.06a
• /
• pp.227-234
• /
• 2004

For gaseous fuel combustion with inherent $CO_2$ capture and low NOx emission, chemical-looping combustion(CLC) may yield great advantages of savings of energy to $CO_2$ separation and suppressing the effect on environment. In chemical-looping combustor, fuel is oxidized by metal oxide medium (oxygen carrier particle) in a reduction reactor. Reduced particles are transported to oxidation reactor and oxidized by air and recycled to reduction reactor. The fuel and the air are never mixed, and the gases from reduction reactor, $CO_2$ and $H_2O$, leave the system as separate stream. The $H_2O$ can be easily separated by condensation and pure $CO_2$ is obtained without any loss of energy for separation. The purpose of this study is to demonstrate inherent $CO_2$ separation and no NOx emission and to confirm high $CO_2$ selectivity, no side reaction (i.e., carbon deposition, hydrogen generation) by continuous reduction and oxidation experiment in a 50kWtb chemical-looping combustor. NiO/bentonite particle was used as a bed material and $CH_4$ and air were used as reacting gases for reduction and oxidation respectively.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.20 no.2
• /
• pp.97-105
• /
• 2008

This paper presents simulated and experimental test results of optimal control algorithm for an encapsulated ice thermal storage system with full capacity chiller operation. The algorithm finds an optimal combination of a chiller and/or a storage tank operation for the minimum total operation cost through a cycle of charging and discharging. Dynamic programming is used to find the optimal control schedule. The conventional control strategy of chiller-priority is the baseline case for comparing with the optimal control strategy through simulation and experimental test. Simulation shows that operating cost for the optimal control with chiller on-off operation is not so different from that with chiller part load capacity control. As a result from the experimental test, the optimal control operation according to the simulated operation schedule showed about 14 % of cost saving compared with the chiller-priority control.