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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 36, Issue 8 - Nov 2012
Volume 36, Issue 7 - Nov 2012
Volume 36, Issue 6 - Sep 2012
Volume 36, Issue 5 - Jul 2012
Volume 36, Issue 4 - May 2012
Volume 36, Issue 3 - May 2012
Volume 36, Issue 2 - Mar 2012
Volume 36, Issue 1 - Jan 2012
Selecting the target year
Efficiency and Exergy Analysis of New Liquefaction Cycles Applied for LNG FPSO
Yoon, Jung-In ; Son, Chang-Hyo ; Baek, Seung-Moon ; Kwag, Jin-Woo ; Shim, Gyu-Jin ;
Journal of the Korean Society of Marine Engineering, volume 36, issue 5, 2012, Pages 574~579
DOI : 10.5916/jkosme.2012.36.5.574
This paper presents the new cascade liquefaction cycles using
. The performance and exergy of cascade liquefaction cycles are analyzed using HYSYS software and then confirmed the possibility of these cycles for LNG-FPSO ship. From the comparison of performance and exergy loss of these cycles, the cascade liquefaction cycles using
showed higher performance and the cycle using
presented higher exergy loss. The cascade liquefaction cycle using
is lower efficiency and higher compressor work compared to the optimized cascade liquefaction cycle using
. But, if the efficiency of
cycle in these liquefaction cycles is improved, it is possible to apply the cascade liquefaction cycle using
to LNG-FPSO ship due to the simple composition device of these cycles.
Performance Characteristics of R744 OTEC Power Cycle with Operation Parameters
Yoon, Jung-In ; Son, Chang-Hyo ; Baek, Seung-Moon ; Kim, Hyeon-Ju ; Lee, Ho-Saeng ;
Journal of the Korean Society of Marine Engineering, volume 36, issue 5, 2012, Pages 580~585
DOI : 10.5916/jkosme.2012.36.5.580
In this paper, the cycle performance analysis for condensation and evaporation capacity, total work and efficiency of ocean thermal energy conversion power system using R744 (
) is presented to offer the basic design data for the operating parameters of this system. The operating parameters considered in this study include superheating and subcooling degree, evaporation and condensation temperature, pump and turbine efficiency. The main results were summarized as follows : The evaporation capacity of R744 increases with superheating and subcooling degree, but decreases with the increasing condensation temperature. The total work increases with superheating and subcooling degree of R744, but decreases with the increasing evaporating temperature. And, the efficiency increases with subcooling and superheating degree, but decreases with the increasing condensation temperature. Therefore, superheating and subcooling degree, evaporation and condensation temperature and pump and turbine efficiency of R744 OTEC power system have an effect on the evaporation and condensation capacity, total work and efficiency of this system. With a thorough grasp of these effect, it is necessary to design the OTEC power cycle using R744.
Performance Analysis of GT/ST Hybrid System for Marine Power Applications(under Conditions of Air-Cooled Gas Turbine)
Kim, Sun-Hee ; Jung, Byung-Gun ; Kim, Myoung-Hwan ;
Journal of the Korean Society of Marine Engineering, volume 36, issue 5, 2012, Pages 586~594
DOI : 10.5916/jkosme.2012.36.5.586
A future type ship power system requires both economic and eco-friendliness. That is, this should be reduced the discharge quantity of air pollutants and green-house gases as well as have high energy efficiency. Recently, gas turbines have been realized a lot of technical development in terms of efficiency and safety, and are widening the example of their adoption to a GT/ST hybrid system in a power plant as well as an aviation use. This paper reviewed the performance characteristics of a GT/ST hybrid system of several ten MW class, not large capacity, with a simulation in order to evaluate the possibility of a GT/ST hybrid system for ships. The reviewed GT/ST hybrid system has maximum 49 % efficiency, has the highest efficiency point for TIT, and has a 70~75 % and 25~30 % load ratio for a gas turbine and a steam turbine respectively.
A Optimization of the ORC for Ship's Power Generation System
Oh, Cheol ; Song, Young-Uk ;
Journal of the Korean Society of Marine Engineering, volume 36, issue 5, 2012, Pages 595~602
DOI : 10.5916/jkosme.2012.36.5.595
In this study, for the purpose of reduction of
gas emission and to increase recovery of waste heat from ships, the ORC (Organic Rankine Cycle) is investigated and offered for the conversion of temperature heat to electricity from waste heat energy from ships. Simulation was performed with waste heat from the exhaust gasse which is relatively high temperature and cooling sea water which is relatively low temperature from ships. Various fluid is used for simulation of the ORC system with variable temperature and flow condition and efficiency of system and output power is compared. Finally, 2,400kW output power is obtained by system optimization of the preheater and reheater utilizing waste heat form sea water cooling system.
Effects of Fuel Injection Timing on Exhaust Emissions Characteristics of Biodiesel Blend Oil in Diesel Engine
Lim, Jae-Keun ; Cho, Sang-Gon ;
Journal of the Korean Society of Marine Engineering, volume 36, issue 5, 2012, Pages 603~608
DOI : 10.5916/jkosme.2012.36.5.603
Recently we have a growing interest in environmental pollution and alternative energy. Diesel engine is generally used to produce the power on shore and sea. However, the combustion characteristics and exhaust emissions of the engine are changed on account of the wear of fuel system and the altered ambient condition of the combustion chamber by the increment of the engine operation hour. Therefore the combustion characteristics and exhaust emissions on the fuel injection timing were experimentally investigated to find out the optimum fuel injection timing in case of the about 20 years used diesel engine using biodiesel blend oil. The original fuel injection timing of the engine is BTDC
CA. However, it is found that the optimum fuel injection as a result of analyzing the specific oil consumption and exhaust emissions of 20 years used the engine is BTDC
Flow Characteristics of Polluted Air in a Rectangular Tunnel using PIV and CFD
Lee, Yong-Ho ;
Journal of the Korean Society of Marine Engineering, volume 36, issue 5, 2012, Pages 609~617
DOI : 10.5916/jkosme.2012.36.5.609
The flow characteristics of polluted air are analysed by comparing the results obtained from PIV(Particle Image Velocimetry) experiment and CFD(Computational Fluid Dynamics) commercial code. In order to simulate the polluted air flow, the olive oil has been used as tracer particles with the kinematic viscosity of air,
. The investigation has done in the range of Reynolds numbers of 870, 1730 and 2890 due to the inlet flow velocities of 0.3, 0.6, and 1.0 m/s, respectively. The average velocity and the pressure distributions are comparatively discussed with respect to the three different Reynolds numbers. The results show that the outlet flow rates at three different Reynolds numbers are equivalent of 165 to 167 percent of the inlet ones. The pressure drop occurs in the model closed at both end sides and the highest pressures at each Reynolds number are positioned at the top of the tunnel between the inlet and outlet.
Internal Flow Characteristics in the Draft Tube of a Francis Turbine
Wei, Qingsheng ; Zhu, Baoshan ; Choi, Young-Do ;
Journal of the Korean Society of Marine Engineering, volume 36, issue 5, 2012, Pages 618~626
DOI : 10.5916/jkosme.2012.36.5.618
Suppression of abnormal flow phenomena in the Francis hydro turbine is very important to improve the turbine performance. Especially, as cavitation and cavitation surge makes serious problems when the turbine is operated in the range of partial flow rate, optimum method of suppressing the abnormal flow characteristics is required necessarily. Moreover, as swirl flow in the draft tube of the Francis turbine decreases pressure at the inlet of the draft tube, suppression of the swirl flow can be an useful method of suppressing the occurrence of cavitation. In order to clarifying the possibility of suppressing the swirl flow by J-Groove in the draft tube, a series of CFD analysis has been conducted in the range of partial load, designed condition and excessive flow rate of a Francis turbine. A kind of J-Groove is designed and applied to the draft tube of the Francis hydro turbine model. The pressure contours, circumferential velocity vectors and vortex core regions in the draft tube are compared by the conditions with or without J-Groove. In addition, a group of data about the velocity in the draft is presented to show the influence of J-Groove.
Hydrodynamic Evaluation Method for Developing the Inflatable Kayak
Ki, Jae-Seok ; Hah, Chong-Ku ; Jang, Ho-Yun ;
Journal of the Korean Society of Marine Engineering, volume 36, issue 5, 2012, Pages 627~634
DOI : 10.5916/jkosme.2012.36.5.627
This study includes results of basin test for hydrodynamic performance evaluation with a developed inflatable kayak. Inclining experiment and turning trial experiment of the developed inflatable kayak and an abroad product were carried out in the Ocean engineering Basin. Resistance test was carried out by using downscale model in the circulating water channel. Through method of following performance evaluation, advantage and disadvantage of the developed inflatable kayak were compared with those of the abroad product.
Numerical Study on Energy Absorption of a Floater for Design of Wave Energy Convertor in Ocean
Li, Kui Ming ; Parthasarathy, Nanjundan ; Choi, Yoon-Hwan ; Lee, Yeon-Won ;
Journal of the Korean Society of Marine Engineering, volume 36, issue 5, 2012, Pages 635~644
DOI : 10.5916/jkosme.2012.36.5.635
In order to design a wave energy generating system, a 6-DOF analysis technique is applied to the three-Dimensional CFD analysis on of a floating body and the behavior is interpreted according to the nature of the incoming wave. A wave period of 5.5s & amplitude of 0.57m from Marado is chosen. 12 case of natural pitching period from 1.25 to 2.8s has been modeled. The relation between tuning factor & pitch angle for the waves generated is compared to analyze the effects of energy absorption variables, namely mass moment of inertia, angular velocity and angular acceleration. From the results obtained, we conclude that model L is the maximum power absorbed, 6kW approximately. A maximum pitch angle of 1.91 degree was attained by Model F, and the maximum displacement of nearly 0.7m was attained by Model L among models D, F and L.
Invader Detection System Using the Morphological Filtering and Difference Images Based on the Max-Valued Edge Detection Algorithm
Lee, Jae-Hyun ; Kim, Sung-Shin ; Kim, Jung-Min ;
Journal of the Korean Society of Marine Engineering, volume 36, issue 5, 2012, Pages 645~661
DOI : 10.5916/jkosme.2012.36.5.645
Recently, pirates are infesting on the sea and they have been hijacking the several vessels for example Samho Dream and Samho Jewelry of Korea. One of the items to reduce the risk is to adopt the invader detection system. If the pirates break in to the ship, the detection system can monitor the pirates and then call the security alarm. The crew can gain time to hide to the safe room and the report can be automatically sent to the control room to cope with the situation. For the invader detection, an unmanned observation system was proposed using the image detection algorithm that extracts the invader image from the recording image. To detect the motion area, the difference value was calculated between the current image and the prior image of the invader, and the 'AND' operator was used in calculated image and edge line. The image noise was reduced based on the morphology operation and then the image was transformed into morphological information. Finally, a neural network model was applied to recognize the invader. In the experimental results, it was confirmed that the proposed approach can improve the performance of the recognition in the invader monitoring system.
Fault Detection of Governor Systems Using Discrete Wavelet Transform Analysis
Kim, Sung-Shin ; Bae, Hyeon ; Lee, Jae-Hyun ;
Journal of the Korean Society of Marine Engineering, volume 36, issue 5, 2012, Pages 662~673
DOI : 10.5916/jkosme.2012.36.5.662
This study introduces a condition diagnosis technique for a turbine governor system. The governor system is an important control system to handle turbine speed in a nuclear power plant. The turbine governor system includes turbine valves and stop valves which have their own functions in the system. Because a turbine governor system is operated by high oil pressure, it is very difficult to maintain under stable operating conditions. Turbine valves supply oil pressure to the governor system for proper operation. Using the pressure variation of turbine and governor valves, operating conditions of the turbine governor control system are detected and identified. To achieve automatic detection of valve status, time-based and frequency-based analysis is employed. In this study, a new approach, wavelet decomposition, was used to extract specific features from the pressure signals of the governor and stop valves. The extracted features, which represent the operating conditions of the turbine governor system, include important information to control and diagnose the valves. After extracting the specific features, decision rules were used to classify the valve conditions. The rules were generated by a decision tree algorithm (a typical simple method for data-based rule generation). The results given by the wavelet-based analysis were compared to detection results using time- and frequency-based approaches. Compared with the several related studies, the wavelet transform-based analysis, the proposed in this study has the advantage of easier application without auxiliary features.
Implementation of a Stereo Vision Using Saliency Map Method
Choi, Hyeung-Sik ; Kim, Hwan-Sung ; Shin, Hee-Young ; Lee, Min-Ho ;
Journal of the Korean Society of Marine Engineering, volume 36, issue 5, 2012, Pages 674~682
DOI : 10.5916/jkosme.2012.36.5.674
A new intelligent stereo vision sensor system was studied for the motion and depth control of unmanned vehicles. A new bottom-up saliency map model for the human-like active stereo vision system based on biological visual process was developed to select a target object. If the left and right cameras successfully find the same target object, the implemented active vision system with two cameras focuses on a landmark and can detect the depth and the direction information. By using this information, the unmanned vehicle can approach to the target autonomously. A number of tests for the proposed bottom-up saliency map were performed, and their results were presented.
A Bidirectional Korean-Japanese Statistical Machine Translation System by Using MOSES
Lee, Kong-Joo ; Lee, Song-Wook ; Kim, Jee-Eun ;
Journal of the Korean Society of Marine Engineering, volume 36, issue 5, 2012, Pages 683~693
DOI : 10.5916/jkosme.2012.36.5.683
Recently, statistical machine translation (SMT) has received many attention with ease of its implementation and maintenance. The goal of our works is to build bidirectional Korean-Japanese SMT system by using MOSES  system. We use Korean-Japanese bilingual corpus which is aligned per sentence to train the translation model and use a large raw corpus in each language to train each language model. The proposed system shows results comparable to those of a rule-based machine translation system. Most of errors are caused by noises occurred in each processing stage.
A Study on the Sensorless Speed Control of Permanent Magnet Direct Current Motor
Oh, Sae-Gin ; Kim, Hyun-Chel ; Kim, Jong-Su ; Yoon, Kyoung-Kuk ;
Journal of the Korean Society of Marine Engineering, volume 36, issue 5, 2012, Pages 694~699
DOI : 10.5916/jkosme.2012.36.5.694
This paper proposes a new sensorless speed control scheme of permanent magnet DC motor using a numerical model and hysteresis controller, which requires neither shaft encoder, speed estimator nor PI controllers. By supplying the identical instantaneous voltage to both model and motor in the direction of reducing torque difference, the rotor speed approaches to the model speed, namely setting value and the system can control motor speed precisely. As the numerical model whose electric parameters are the same as those of the actual motor is adopted, the armature rotating speed can be converged to the setting value by controlling torque on both sides to be equalized. And the hysteresis controller controls torque by restricting the torque errors within respective hysteresis bands, and motor torque are controlled by the armature voltage. The experiment results indicate good speed and load responses from the low speed range to the high, show accurate speed changing performance.
Development of an Electronic Starting Controller for Starting Motor of Packaged Power Systems
Kim, Jong-Su ; Yoon, Kyoung-Kuk ; Seo, Dong-Hoan ;
Journal of the Korean Society of Marine Engineering, volume 36, issue 5, 2012, Pages 700~706
DOI : 10.5916/jkosme.2012.36.5.700
The core technology of a starting device in the packaged power system is the pinion gear shifting device and to limit the initial starting voltage. Although the conventional products have been used the starting controller using mechanical contactor, these have a big problem such as the uncertainty for the start of starting motor after a pinion gear is completely shifted or the arc demage due to high current. In this study, in order to solve these problems, we designed and fabricated a new product to achieve the safety and reliability as follows: the pinion gear-shifting control circuits to eliminate the uncertainty of the start, the starting control system using semiconductor device to prevent the arc demage of contactor caused by high current, a start safety devices for soft starting of series motor. In addition, we obtained the electrical safety by separating the pinion gear control circuit and the source circuit of motor.
Ocean Wave Energy Converters - A Perspective
Parthasarathy, Nanjundan ; Li, Kui Ming ; Choi, Yoon-Hwan ; Lee, Yeon-Won ;
Journal of the Korean Society of Marine Engineering, volume 36, issue 5, 2012, Pages 707~715
DOI : 10.5916/jkosme.2012.36.5.707
Ocean waves are mighty and powerful. Humans have explored the possibility of harnessing this mighty power for decades now. Estimated as suffice, if only, a fraction of this energy is captured and harnessed, the worry for decrease in fossil fuels diminishes and the current energy consumption of the world can be met. Though different types of methods and devices for extracting energy from this nonstop, free source has been proposed, a handful of them have reached commercialization and others are on the verge. This paper discusses the journey so far in terms of devices that have been developed or prototypes proposed or commercialized. Only a list full of them have been discussed though they exist in numbers.