• Journal of the Korean Vacuum Society
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• v.18 no.4
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• pp.318-330
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• 2009

A high heat flux test facility using a graphite heating panel was constructed and is presently in operation at Korea Atomic Energy Research Institute, which is called KoHLT-1. Its major purpose is to carry out a thermal cycle test to verify the integrity of a HIP (hot isostatic pressing) bonded Be mockups which were fabricated for developing HIP joining technology to bond different metals, i.e., Be-to-CuCrZr and CuCrZr-to-SS316L, for the ITER (International Thermonuclear Experimental Reactor) first wall. The KoHLT-1 consists of a graphite heating panel, a box-type test chamber with water-cooling jackets, an electrical DC power supply, a water-cooling system, an evacuation system, an He gas system, and some diagnostics, which are equipped in an authorized laboratory with a special ventilation system for the Be treatment. The graphite heater is placed between two mockups, and the gap distance between the heater and the mockup is adjusted to $2{\sim}3\;mm$. We designed and fabricated several graphite heating panels to have various heating areas depending on the tested mockups, and to have the electrical resistances of $0.2{\sim}0.5$ ohms during high temperature operation. The heater is connected to an electrical DC power supply of 100 V/400 A. The heat flux is easily controlled by the pre-programmed control system which consists of a personal computer and a multi function module. The heat fluxes on the two mockups are deduced from the flow rate and the coolant inlet/out temperatures by a calorimetric method. We have carried out the thermal cycle tests of various Be mockups, and the reliability of the KoHLT-1 for long time operation at a high heat flux was verified, and its broad applicability is promising.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.344-347
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• 2011

This paper presents qualification process of the T700/701K turbo-shaft engine for Korean Utility Helicopter(KUH). The T700/701K is the rear-drive variant of the GE's T700-701C/D engine which was qualified for military applications in the world. The main scope of the development is the modification from a front-drive engine to a rear-drive one, the performance enhancement of the power turbine and the incorporation of two channel FADEC(Full Authority Digital Engine Control) system for more reliable operation. Therefore, T700/701K engine must be qualified by Korean government in order to perform a flight in the country. Reflecting the influence of developing scope, the main requirements including performance and control are verified by test and analysis, while the requirement for module or component that is same to that of T700-701C/D are verified by similarity.

• Magazine of the Korean Society of Agricultural Engineers
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• v.14 no.1
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• pp.2535-2548
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• 1972

Instead of fertilizing the lands they moved to find other fertile lands and lived a feudal life agriculture and various machincs played a main role in the land reclamation. The best method of land clearing, the time and capacity in the operation and the effect of growing crops should systematically analized prior to the time of 3rd Five-year Economic Development(1972-1976) in order to cultivate 210,000ha of wasteland or the modernization of our country. The present study was investigated to find out a new working-system of mechanical land clearing and development of fertile soil. The results are as follows: 1) The first stage of productive power increases when weeds were mixed soil in the land clearing work in order to supply organic materials and to make soil swollen instead of burning or just removing. 2) The equipments such as bulldozers, harrows, power tillers and so on should be prepared in order to do a systematic work in the land clearing. 3) The work of pulling-up roots is dependent upon the forms of roots spreading under the ground. The work of the pulling-up of the straight roots was most difficult. But before the roots are pulling-up we do not know the forms of roots. 4) The cutting of soil from upside to under side land clearing method (II) Spent 6 hr 7 min 43 sec per 1 Danbo in doing land clearing and control method spent 4 hr 52 min 30 sec per 1 Danbo in doing land cearing. No significant difference could be found between II treatment type and I treatment type. 5) The volume of soil carried by bulldozer $270.38m^3$ per 1 Danbo in I type and in II type, $368.58m^3$ per 1 Danbo or about 36% increased in II type then in I type. But that is not a significant difference when considering the whole productive power of soil. 6) The land clearing of terrace by bulldozers cannot escape making the embankment slope of about $45^{\circ}$, and 25.3% should be decreased in the area. It is recommended to make use of the embankment slope by planting grass for cows. 7) The time of retary tilling increased 2.3 times or 1 hr 42 min 22 sec per 1 Danbo compared to the timesrequired in the harrowing. Because it mixed the Organic matter on ground and the harrowing of subsoil. 8) The havest of pasture growing on the land reclamation in natural slope is as follows. (a) The none fertilizers with reclaimed block of productivity decresed 1/10 than that of the farmland. Therefore the none fer tilizing in the cultivated pasture is unprofitable. (b) The havest of the manured IV treatment block was the best not only in the kinds of fertilizers but also in the kinds of pasture grass.

• Journal of Drive and Control
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• v.17 no.4
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• pp.141-151
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• 2020

The aim of this study was to analyze the safety factor of range-shift gear pairs on multi-purpose agricultural implement machinery for an optimal design of a transmission system. Gear-strengths such as bending and contact stress and safety factors were analyzed under three load conditions: an equivalent engine torque at plow tillage, a rated engine torque, and the maximum engine torque. Root and contact safety factor were calculated to be 3.88, 5.14, 2.24, 2.11, 2.21, 0.99 and 0.78, 0.94, 0.65, 0.68, 0.84, 0.85, respectively, under equivalent engine torque condition at the plow tillage. The root and contact safety factor were calculated to be 1.91, 2.53, 1.10, 1.04, 1.07, 0.48 and 0.55, 0.66, 0.46, 0.48, 0.59, 0.59, respectively, under rated engine torque condition. The root and contact safety factor were calculated to be 1.60, 2.11, 0.92, 0.87, 0.90, 0.40 and 0.51, 0.61, 0.42, 0.44, 0.54, 0.54, respectively, under the maximum engine torque condition. The multi-purpose agricultural implement machinery could be conducted under plow tillage operation. However, gear specifications for tooth surface need modification because the gear surface would be broken at all driving conditions as safety factors are lower than 1.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.9
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• pp.1025-1031
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• 2019

This study proposes a PCS that enables efficient operation of seawater pumps for ships by implementing ML-based algorithms. Seawater temperature, RPM and power consumption data are acquired from two ships with PCS, analyzed with regression analysis method, and new algorithms are presented. Using the algorithms presented, Ship A saved about 36% compared to the PCS application, and ML-based algorithms in certain sea temperatures of 19 to 27 degrees Celsius and above 32 degrees Celsius were about 1% lower than Ship A's PCS. Ship B saved about 50% compared to PCS not applied, and about 2% more than Ship B's PCS in waters above $19^{\circ}C$, a specified sea temperature. The derived data can be used to suggest the optimum pump speed and sea route. In addition, the trend of acquired data can be used to infer the performance of the pump or the timing of elimination of the MGPS when efficiency becomes poor.

• Journal of Navigation and Port Research
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• v.28 no.1
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• pp.43-49
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• 2004

Defects inspection of commodities are very important with those design and manufacturing process and essential to strengthen the competitiveness of those. If on-line automatic defects detection is performed without damaging to products, the production cost shall be curtailed through the reducing man-power, economical management of Q.C(Quality Control). In this paper, it is suggested three spatial filtering methods which can extract the necessary information in case of defects being on the surface of object like iron plate. In addition, the dependence of filtering characteristics on parameters such as the pitch and width of slits is analyzed and the surface defect detection system is constructed. Several experiments were carried out for determining the adequate spatial filtering method through comparing and analyzing effects of parameters like defect's size and shape, intensity of light, noise of coherent source and slit number.

• Mass Spectrometry Letters
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• v.2 no.1
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• pp.1-7
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• 2011

China's rapid economic growth has resulted in significant environmental side effects. Therefore, China has been interested in reducing her dependence on foreign oil and gas by developing technologies needed for hydrogen, in addition to her increasing energy mix of nuclear and renewable energy form, such as solar and wind power. There are three isotopes of hydrogen, i.e. protium (P or H), deuterium (D), and tritium (T). Both deuterium and tritium are important materials in nuclear fuel cycle industry. Tritium is one of the critical radioactive nuclides. Planning for and implementing contamination control as a part of normal operation and maintenance activities is an important function in any hydrogen facility, especially tritium facility. The development of hydrogen isotopes analysis is the key issues in this area. Mass spectrometry (MS) with medium (about 600) and high resolution (> 1,400) is commercially available; however, the routine analysis of hydrogen isotopes is done with low-resolution MS (< 200) in China. This paper summarizes the progress of MS measurement technology for hydrogen isotope abundance in China, focusing on our lab's research program and technical status. An analyzing method has been introduced for accurate measurement of tritium abundance in the H.D.T system by low resolution MAT-253 MS. The quotient of compression ratio coefficient is determined by building up equipment for laboratory-scale preparation of secondary standard gases and by considering the difference in sensitivity between hydrogen isotopes. The results show that the measured value is reproducible within the relative error range of 0.8% for gas samples of different tritium abundance.

• Proceedings of the Korea Society for Simulation Conference
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• 2000.11a
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• pp.61-66
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• 2000

The KEPRI has been upgrading the KNPEC(Korea Nuclear Power Education Center) #2 simulator, a replica of Yonggwang Unit 1 & 2, due to the outdated systems. The scenarios, such as the continuous load change, are selected to verify and validate the simulator, and the data required to V&V are generated with the best-estimated codes, RETRAN and MARS. The reactor coolant system and steam generator system are cut up into volumes and junctions for the accurate model of the scenarios, and other components and control systems are modeled. For the model the operation and design data of the plants is used and in some cases the data of Kori Unit 3 & 4 is used to fill up the lack of required data. The results of some selected analyses with the models are compared with the operating data of the plants to verify the models, and the analyses of the scenarios are carried out to generated the data for the V&V of the simulator

• Transactions of the Korean hydrogen and new energy society
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• v.24 no.1
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• pp.12-19
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• 2013

A gasification process with pre-combustion $CO_2$ capture process, which converts coal into environment-friendly synthetic gas, might be promising option for sustainable energy conversion. In the coal gasification for power generation, coal is converted into $H_2$, CO and $CO_2$. To reduce the cost of $CO_2$ capture and to maximize hydrogen production, the removal of CO and the additional production of hydrogen might be needed. In this study, a 2l/min water gas shift system for a coal gasifier has been studied. To control the concentration of major components such as $H_2$, CO, and $CO_2$, MFCs were used in experimental apparatus. The gas concentration in these experiments was equal with syngas concentration from dry coal gasifiers ($H_2$: 25-35, CO: 60-65, $CO_2$: 5-15 vol%). The operation conditions of the WGS system were $200-400^{\circ}C$, 1-10bar. Steam/Carbon ratios were between 2.0 and 5.0. The commercial catalysts were used in the high temperature shift reactor and the low temperature shift reactor. As steam/carbon ratio increased, the conversion (1-$CO_{out}/CO_{in}$) increased from 93% to 97% at the condition of CO: 65, $H_2$: 30, $CO_2$: 5%. However the conversion decreased with increasing of gas flow and temperature. The gas concentration from LTS was $H_2$: 54.7-60.0, $CO_2$: 38.8-44.9, CO: 0.3-1%.

• Journal of Korean Society for Atmospheric Environment
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• v.32 no.5
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• pp.526-535
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• 2016

Recently, fine dust in atmosphere have been considerably issued as a harmful element for human. Nitrogen oxide ($NO_x$) exhausted from diesel engines and power plants has been disclosed as a main source of secondary production of fine dust. In order to prevent exhausting these nitrogenous compounds into atmosphere, a treatment system with selective catalytic reduction (SCR) catalyst with ammonia as a reductant has been used in various industries. Urea solution has been widely studied to supply ammonia into a SCR catalytic reactor, safely. However, the conversion of urea solution to ammonia has several challenges, especially on a slow conversion velocity. In the present study, a fast urea conversion system including a plasma burner was suggested and designed to evaluate the performances of urea conversion and initial operation time. A designed lab-scale facility has a plasma burner, urea nozzle, mixer, and SCR catalyst which is for hydrolysis of isocyane. Flow rate of methane that is a fuel of the plasma burner was varied to control temperatures in the urea conversion facility. From experimental results, it is found that urea can be converted into ammonia using high temperature condition of above $400^{\circ}C$. In the designed test facility, it is found that ammonia can be produced within 1 min from urea injection and the result shows prospect commercialization of proposed technology in the SCR facilities.