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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Society of Marine Engineering
Journal Basic Information
Journal DOI :
Korean Society of Marine Engineers
Editor in Chief :
Volume & Issues
Volume 40, Issue 6 - Jul 2016
Volume 40, Issue 5 - Jun 2016
Volume 40, Issue 4 - May 2016
Volume 40, Issue 3 - Mar 2016
Volume 40, Issue 2 - Feb 2016
Volume 40, Issue 1 - Jan 2016
Selecting the target year
A fouling mitigation device for a wastewater heat recovery heat pump system using a bubbling fluidized bed with cleaning sponge balls
Kim, Jong-Soo ; Kim, Do-Bin ; Kim, Jun-Ha ;
Journal of the Korean Society of Marine Engineering, volume 40, issue 3, 2016, Pages 152~156
DOI : 10.5916/jkosme.2016.40.3.152
Wastewater heat recovery heat pump systems use heated wastewater from public baths or factories as the heat pump's heat source. Generally, this system uses a bare tube evaporator. In the heat transfer process from wastewater to refrigerant, thermal resistance is caused primarily by fouling deposits on the outside surface of tube. Fouling directly increases thermal resistance and decreases heat pump efficiency. Thus, it is desirable to eliminate fouling. In this study, we fabricated a fouling mitigation device using a bubbling fluidized bed with cleaning sponge balls in the wastewater bath. Experimental conditions were as follows:
wastewater temperature, 100 L/h cold water flow rate, and
heat exchanger surface area. Experimental results showed that the thermal resistance of fouling decreased by 56% with the fluidized bed alone and by 86% with both the fluidized bed and cleaning sponge balls.
Design of a pilot-scale helium heating system to support the SI cycle
Jang, Se-Hyun ; Choi, Yong-Suk ; Lee, Ki-Young ; Shin, Young-Joon ; Lee, Tae-Hoon ; Kim, Jong-Ho ; Yoon, Seok-Hun ; Choi, Jae-Hyuk ;
Journal of the Korean Society of Marine Engineering, volume 40, issue 3, 2016, Pages 157~164
DOI : 10.5916/jkosme.2016.40.3.157
In this study, researchers performed preliminary design and numerical analysis for a pilot-scale helium heating system intended to support full-scale construction for a sulfur-iodine (SI) cycle. The helium heat exchanger used a liquefied petroleum gas (LPG) combustor. Exhaust gas velocity at the heat exchanger outlet was approximately 40 m/s based on computational thermal and flow analysis. The maximum gas temperature was reached with six baffles in the design; lower gas temperatures were observed with four baffles. The amount of heat transfer was also higher with six baffles. Installation of additional baffles may reduce fuel costs because of the reduced LPG exhausted to the heat exchanger. However, additional baffles may also increase the pressure difference between the exchanger's inlet and outlet. Therefore, it is important to find the optimum number of baffles. Structural analysis, followed by thermal and flow analysis, indicated a 3.86 mm thermal expansion at the middle of the shell and tube type heat exchanger when both ends were supported. Structural analysis conditions included a helium flow rate of 3.729 mol/s and a helium outlet temperature of
. An exhaust gas temperature of
and an exhaust gas rate of 52 g/s were confirmed to achieve the helium outlet temperature of
with an exchanger inlet temperature of
in an LPG-fueled helium heating system.
Hydrogen explosion effects at a containment building following a severe accident
Ryu, Myeong-Rok ; Park, Kweon-Ha ;
Journal of the Korean Society of Marine Engineering, volume 40, issue 3, 2016, Pages 165~173
DOI : 10.5916/jkosme.2016.40.3.165
On March 11, 2011, a massive earthquake measuring 9.0 on the Richter scale and subsequent 10-.14 m waves struck the Fukushima Daiichi (FD) Nuclear Power Plant. The main and backup electric power was damaged preventing the cooling system from functioning. Fuel rods overheated and led to hydrogen explosions. If heat in the fuel rods is not dissipated, the nuclear fuel coating material (e.g., Zircaloy) reacts with water vapor to generate hydrogen at high temperatures. This hydrogen is released into the containment area. If the released hydrogen burns, the stability of the containment area is significantly impacted. In this study, researchers performed an explosion analysis in a high-risk explosion area, analyzing the hydrogen distribution in a containment building  and the effects of a hydrogen explosion on containment safety. Results indicated that a hydrogen explosion was possible throughout the containment building except the middle area. If an explosion occurs at the top of the containment building with more than 40% of the hydrogen collected or in the bottom right or left side of the of containment building, safety of the containment building could be threatened.
Characteristics of boil-off-gas partial re-liquefaction systems in LNG ships
Yun, Sang-Kook ;
Journal of the Korean Society of Marine Engineering, volume 40, issue 3, 2016, Pages 174~179
DOI : 10.5916/jkosme.2016.40.3.174
To protect the ocean environment, the use of liquefied natural gas (LNG) carriers, bunkering ships, and fueled ships is increasing. Recently, Korean shipbuilders have developed and supplied a partial reliquefaction facility for boil-off-gas (BOG). Despite reasonable insulation, heat leakage in vessel storage tanks causes LNG to be continuously evaporated as BOG. This research analyzed the maximum liquid yield rate for various partial reliquefaction systems (PRS) and considered related factors affecting yields. The results showed a liquid yield of 48.7% from an indirect PRS system (heat exchanges between cold flash gas and compressed natural gas), and 41% from a direct PRS system (BOG is mixed with flash gas and discharged from a liquid-vapor separator). The primary factor affecting liquid yield was heat exchanger effectiveness; the exchanger's efficiency and insulation characteristics directly affect the performance of BOG reliquefaction systems.
Effect of nozzle diameter on the reduction of smoke emission from naval ship diesel engines
Son, Min-Soo ; Choi, Jae-Sung ; Cho, Kwon-Hae ;
Journal of the Korean Society of Marine Engineering, volume 40, issue 3, 2016, Pages 180~184
DOI : 10.5916/jkosme.2016.40.3.180
Legislative and regulatory actions regarding the exhaust gas from ships are being strengthened by both international organizations and national governments, to protect human health and the environment. Exhaust gas traps are excluded from exhaust gas regulation applications, but, recently, the United States, Britain, and other developed countries have examined a variety of ways to improve the system, including the introduction of electric propulsion systems to prevent air pollution generated by naval ships. This study investigates a large number of smoke problems of naval diesel engines to verify the effect of improving the nozzle characteristics. An exhaust gas emission measurement method to determine the quality of pollutant exhaust gas generated during low-load operation is proposed through the research methodology of the smoke problem. It was confirmed that the emissions value is improved by decreasing the nozzle hole diameter and increasing the injection pressure. At the same time, the flow rate decrease equation and setting up a test memo based on the nozzle diameter confirmed that the fuel consumption, to which the nozzle diameter in the flow path is related, is reduced.
A case study on the optimal shafting alignment concerning bearing stiffness for 10,100 TEU container carrier
Lee, Jae-Ung ;
Journal of the Korean Society of Marine Engineering, volume 40, issue 3, 2016, Pages 185~190
DOI : 10.5916/jkosme.2016.40.3.185
Damages of the main engine aftmost bearing and the after stern tube bearing tend to increase due to misalignment. And as the shafting system becomes stiffer due to the large engine power, whereas the hull structure becomes more flexible due to optimization by using high tensile thin steel plates. And this is the reason that more sophisticated shaft alignments are required. In this study, the optimum shafting alignment calculation was carried out, considering the thermal expansion effect, exploiting the sensitivity index, which indicates the reasonable position of forward intermediate shaft bearing for shaft alignment. and as the main subject in this study, the elastic deformation on intermediate shaft and main engine bearings occurred by vertical load of shaft mass were examined thoroughly and analyzed allowable load of bearings, reaction influence numbers of all bearings. As the result, a reliable optimum shafting alignment was derived theoretically. To verify these results, they were referred to the engine maker's technical information of main engine installation and being used shafting alignment programs of both Korean Register of Shipping and Det Norske Veritas, their reliability were reviewed.
A study of the analysis of shaft alignment considering hull deflections for 50,000 DWT oil/chemical tankers
Lee, Jae-Ung ;
Journal of the Korean Society of Marine Engineering, volume 40, issue 3, 2016, Pages 191~197
DOI : 10.5916/jkosme.2016.40.3.191
The shaft system of a vessel becomes stiffer because of larger engine power, whereas the hull structure becomes more flexible because of scantling optimization conducted by using high-tensile thick steel plates. The draught-dependent deformation of the hull affects each bearing offset and reaction force comprising the subsequent shaft system. This is the reason that more sophisticated shaft alignments are required. In this study, an FE analysis performed under the expected operating conditions of two (2) vessels, as maximum draught change and to analyze the shaft alignment using the relative bearing offset change, which was derived from an FE analysis of the 50,000 DWT oil/chemical tanker, which has become an eco-friendly vessel in recent years. Based on this, the influence of the hull deflection on the bearing offset was reviewed against results for shaft alignment conditions.
Experiments on the flow field of a circular cylinder having a front vertical plate
Ro, Ki-Deok ;
Journal of the Korean Society of Marine Engineering, volume 40, issue 3, 2016, Pages 198~204
DOI : 10.5916/jkosme.2016.40.3.198
The characteristics of the flow field of a circular cylinder having a small vertical plate at the upstream side are investigated by measuring the fluid force on the circular cylinder and by visualizing the flow field using particle image velocimetry. The experimental parameters are the width ratios (H/B = 0.2-0.6) of the vertical plates to the circular cylinder's diameter, and the gap ratios (G/B = 0-3) between the circular cylinder and the vertical plate. The drag reduction rate and Strouhal number of the circular cylinder increased and then decreased with G/B in the case of the same H/B. The drag reduction rate increased with H/B in the case of the same G/B. In the case of a circular cylinder having a small vertical plate, the stagnation regions are represented on the upstream and downstream sides of the circular cylinder, and the size of that region on the upstream side increased with H/B.
Investigation of flowfield characteristics of a square prism having a front triangular prism by PIV
Ro, Ki-Deok ; Kim, Jae-Dong ;
Journal of the Korean Society of Marine Engineering, volume 40, issue 3, 2016, Pages 205~209
DOI : 10.5916/jkosme.2016.40.3.205
The flowfield characteristics of a square prism having a small triangular prism at the upstream side were investigated by visualizing the flow field using PIV. The ratio of the width of the triangular prism to that of the square prism and the gap ratios between the square and triangular prisms were selected as the experimental parameters. The results are summarized as follows. The Strouhal number measured on the wake side of the square prism, which had the same characteristics as the drag reduction rate, increased, and then decreased with the gap ratio for the same width ratio. For a square prism having a small triangular prism, the stagnation regions were represented at the upstream and downstream sides of the square prism. The size of the stagnation region increased with the width ratio at the upstream side of the square prism, and decreased at the downstream side.
Development of NORSOK T-100-based telecom management system for off-shore installation
Mun, Seong-Mi ; Jang, Won-Seok ; Park, Su-Hyun ;
Journal of the Korean Society of Marine Engineering, volume 40, issue 3, 2016, Pages 210~216
DOI : 10.5916/jkosme.2016.40.3.210
Malfunctioning of telecom systems can have serious implications on the safe navigation and operation of vessels and off-shore plants. Most safety-related accidents incur significant monetary damages and pollution due to complicated arrangements of the working environments and facilities. Therefore, an automated monitoring system that can collect data from configured telecom equipment connected to a network based on IP is required to ensure safe navigation and operation of such crucial institutions. This paper reports a list of such system requirements, system functions, and user-centered requirements based on the NORSOK T-100 (a standard of telecom management system). These findings were made through research with the newly designed and developed telecom management system (TMS). The TMS was tested by a testbed configured with CCTV, PA/GA, and other network equipment.
Sensorless speed control of permanent magnet synchronous motor using square-root extended kalman filter
Moon, Cheol ; Kwon, Young-Ahn ;
Journal of the Korean Society of Marine Engineering, volume 40, issue 3, 2016, Pages 217~222
DOI : 10.5916/jkosme.2016.40.3.217
This study investigates the design, analysis, and implementation of the square-root extended Kalman filter by using an algorithm derived by combining the Potter or Carlson algorithm with the modified Gram-Schmidt algorithm, for sensorless speed control of a permanent-magnet synchronous motor. The sensitivity of the Kalman filter to round-off errors is a well-known problem. A possible way to address this limitation is by combining the square-root concept and Kalman filter that can improve the numerical performance and solve instability-related problems such as divergence. This paper presents the design and analysis of the implementation of such a square-root extended Kalman filter. To demonstrate the performance of the proposed filter, experimental results under several operating conditions, such as high and low speeds, reversal rotation, detuned parameters and load test, have been analyzed. Further, code sizes and operation times have been compared. Experimental results establish the performance of the proposed square-root extended Kalman filter-based estimation technique for sensorless speed control of a permanent-magnet synchronous motor.
A novel energy-efficient bridgeless boost AC to DC converter
Yoon, Kyoung-Kuk ; Kim, Seong-Hwan ; Kim, Deok-Ki ;
Journal of the Korean Society of Marine Engineering, volume 40, issue 3, 2016, Pages 223~227
DOI : 10.5916/jkosme.2016.40.3.223
Power supplies make the load compatible with its power source. DC power supplies are extensively used with most electrical and electronic appliances such as computers, television, and audio sets. The presence of non-linear loads results in a low power factor and higher harmonics in the power system. Several techniques for power-factor correction and harmonic reduction have been reported in the literature. This paper proposes a bridgeless boost converter that improves the power factor and reduces the harmonic content in input line currents as compared to full-bridge rectifiers. This bridgeless boost converter eliminates the need of a line-voltage bridge rectifier in conventional boost converter and thereby reduces conduction losses. The effectiveness of the proposed scheme is verified by computer simulations by using the PSIM software.
A study on prediction and improvement method of fire risk for a newly built college dormitory
Kim, Byeol ; Hwang, Kwang-Il ;
Journal of the Korean Society of Marine Engineering, volume 40, issue 3, 2016, Pages 228~234
DOI : 10.5916/jkosme.2016.40.3.228
As a college dormitory has the features of high dwelling density and a floating population that becomes crowded during particular times, when a disaster such as a fire occurs, it has the risk of causing much loss of life. In this study, the fire simulation program Fire Dynamics Simulator (FDS), is used to predict the risk when a fire occurs, to analyze the problem, and to suggest an improvement plan for a new cadet dormitory at an university in Korea. The research results are as follows. When a fire occurred in the ironing room inside the cadet dormitory, a smoke detector operated after 65 seconds. Thirteen seconds later, a sprinkler started to operate. The temperature and carbon monoxide density reached the limit value at 241 and 248 seconds, respectively. Because the limit visibility value was reached within 66 seconds after the occurrence of a fire, it is predicted that preparation must be finished and evacuation should begin within 1 minute after the fire occurs, in order to have no casualties. Synthesizing this dormitory fire risk prediction result, the visibility value is considered to be the most dangerous factor for personal safety. Because of this, installing a smoke extraction system is suggested to secure visibility. After the installation of a smoke extraction system, the problem of smoke diffusion in the corridors improved.
An analytic study on the hull characteristics of ship accidents at low capsizing speeds
Choi, Soon-Man ;
Journal of the Korean Society of Marine Engineering, volume 40, issue 3, 2016, Pages 235~239
DOI : 10.5916/jkosme.2016.40.3.235
The capsizing speed of an unstable vessel with a lost restoring moment can be understood as a unique response to an accident situation, and is naturally affected by such parameters as moment of inertia, metacentric height, and transverse damping coefficient of the hull in the case of free roll motion. Additionally, it is supposed that the analysis of capsize accidents can be further simplified when a vessel's leaning velocity is shown to be quite low. Therefore, capsize accidents with low leaning speeds are desirably categorized in view of rescuing strategies, as opposed to fast capsize accidents, since the attitude of the declining hull can be properly estimated, which allows rescuers to have more time for helping accident cases. This study focuses on deriving some analytical equations based on the roll decay ratio parameter, which describes how a hull under a low-speed capsize is related to the situational hull characteristics. The suggested equations are applied to a particular ship to disclose the analytical responses from the model ship. It was confirmed that the results show the general characteristics of slow capsizing ships.
A study on the performance evaluation and technical development of an eco-environmental photovoltaic solar leisure boat with applied sail control device
Moon, Byung-Young ; Lee, Sung-Bum ; Lee, Ki-Yeol ;
Journal of the Korean Society of Marine Engineering, volume 40, issue 3, 2016, Pages 240~248
DOI : 10.5916/jkosme.2016.40.3.240
As a new technical approach, the achievement of an eco-environmental leisure boat with a photovoltaic system is attempted by simultaneously actuating nine photovoltaic solar panels, in association with an applied sail control system by use of wind. In this approach, the photovoltaic system consists of a solar module, an inverter, a battery, and relevant components, while the sail control device is equipped with a sail up/down and mast-turning instrument. Furthermore, this research conducts a performance evaluation of the manufactured prototype and acquires the purposed quantity value and the development purpose items. The significant items-sail up/down speed (seconds) and mast turning angle (degrees)-are evaluated during the performance test. In the process of the performance evaluation, a wind direction sensitivity of 90% and a maximum instant charging power of 900 W were also obtained. In addition, the maximum sail time is evaluated in order to acquire the optimum quantity.