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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 basic study on development of high-pressure compact steam unit applied hybrid heat exchanger
Kim, Jeung-Hoon ; Lim, Gye-Hun ; Kim, Seung-Hyun ; Jin, Chul-Kyu ; Park, Jae-Hong ; Cho, Sung-Youl ; Hong, In-Ki ; Lee, Sang-Rae ;
Journal of the Korean Society of Marine Engineering, volume 40, issue 6, 2016, Pages 453~457
DOI : 10.5916/jkosme.2016.40.6.453
In various industrial plants such as power generation plants, petrochemical plants, and unit factories, there is an increasing demand for a system that generates hot water using waste or surplus steam. Compact steam unit (CSU), which produces hot water by using steam, is a good solution considering energy reuse. In this study, as a basic study to develop a high-pressure CSU, heat transfer characteristics of a hybrid heat exchanger were investigated through experiments, in order to use the hybrid heat exchanger instead of a conventional plate heat exchanger as the core component of CSU. The experimental results are the followings. Heat balance between the hot side and cold side was satisfied within
. Overall heat transfer coefficient increased linearly as the Reynolds number increased and exceeded
when the flow velocity was above 0.5 m/s. In addition, pressure drop also increased as the Reynolds number increased, and pressure drop per unit length was below 50 kPa/m.
A study on the new manufacturing processes of high quality salt without hazardous ingredients
Kim, Kyung-Geun ; Mun, Soo-Beom ; Shao, Yudo ;
Journal of the Korean Society of Marine Engineering, volume 40, issue 6, 2016, Pages 458~467
DOI : 10.5916/jkosme.2016.40.6.458
Salt is the most important substance in physiological activities of the human body concerning transport of the ingested nutrients into the blood. Thus, the most ideal salt must not contain any harmful ingredients such as cadmium, mercury, lead, and arsenic. However, it is legal to include trace amounts of the hazardous ingredients in salt owing to a technical limitation, because salt is generally obtained from seawater. This paper reported an experimental result about a new method of manufacturing high-quality table salts without hazardous ingredients by using "
low-temperature vacuum drying technology," applied to the sequential extraction phenomenon of seawater with increasing the concentration. The world's best table salt can be produced if the present results are applied and extended to the traditional solar salt industry.
A study on the acoustic performance evaluation of heat recovery ventilator with a sound absorbing duct
Bae, Myung-Whan ; Song, Jun-Young ; Park, Hui-Seong ;
Journal of the Korean Society of Marine Engineering, volume 40, issue 6, 2016, Pages 468~475
DOI : 10.5916/jkosme.2016.40.6.468
The purpose of this study is to investigate the acoustic problems of the conventional heat recovery ventilator and to suggest the methods of noise reduction from a heat recovery ventilator according to the installed location. The noise level, in this study, was measured and discussed as the parameters of size, wind volume and sound absorbing duct length for a heat recovery ventilator based on domestic and international related standards. It is found, as a result, that almost all of noise levels from the small and medium heat recovery ventilators without the sound absorbing duct in the anechoic chamber were higher than the noise standard value of 50 dB(A) regardless of the wind volume, and the noise levels went down when a sound absorbing duct was installed. In addition, the sound pressure level relative to frequency bands according to the length of sound absorbing duct was generally decreased, as the length of sound absorbing duct in the small and medium heat recovery ventilators was big, and the sound pressure level was generally increased, as the wind volume was great.
Performance analysis of an organic Rankine cycle for ocean thermal energy conversion system according to pinch point temperature difference
Kim, Jun-Seong ; Kim, Do-Yeop ; Kang, Ho-Keun ; Kim, You-Taek ;
Journal of the Korean Society of Marine Engineering, volume 40, issue 6, 2016, Pages 476~483
DOI : 10.5916/jkosme.2016.40.6.476
An organic Rankine cycle for ocean thermal energy conversion system is a generating cycle using the temperature difference between surface water and deep water of the ocean. The working fluid is an important factor in the thermodynamic performance of an organic Rankine cycle. There is pinch point analysis as thermodynamic analysis of an organic Rankine cycle. This study performed a thermodynamic performance analysis according to variation in the pinch point temperature difference in heat exchangers and variation of outlet temperature of heat source and heat sink. It analyzed the thermodynamic performance by applying seven types of simple working fluids in a simple Rankine cycle for ocean thermal energy conversion that was designed according to pinch point analysis. As a result of the performance analysis, cycle irreversibility and total exergy destruction factor more decreased, and second law efficiency more increased in the lower pinch point temperature difference and temperature variation of heat source and heat sink in heat exchangers. In addition, the irreversibility changed greatly at a point that occurred in the thermodynamic variation. Among the selected working fluids, RE245fa2 showed the best thermodynamic performance, and the performance of all working fluids was observed to be similar. It needs a strict theoretical basis about diverse factors with thermodynamic performances in selecting heat exchangers and working fluids.
Performance and structural analysis of a radial inflow turbine for the organic Rankine cycle
Kim, Do-Yeop ; Kim, You-Taek ;
Journal of the Korean Society of Marine Engineering, volume 40, issue 6, 2016, Pages 484~492
DOI : 10.5916/jkosme.2016.40.6.484
The turbine is an important component and has a significant impact on the thermodynamic efficiency of the organic Rankine cycle. A precise preliminary design is essential to developing efficient turbines. In addition, performance analysis and structural analysis are needed to evaluate the performance and structural safety. However, there are only a few exclusive studies on the development process of the radial inflow turbines for the organic Rankine cycle (ORC). In this study, a preliminary design of the ORC radial inflow turbine was performed. Subsequently, the performance and structural analysis were also carried out. The RTDM, which was developed as an in-house code, was used in the preliminary design process. The results of the performance analysis were found to be in good agreement with target performances. Structural analysis of the designed turbine was also carried out in order to determine whether the material selection for this study is suitable for the flow conditions of the designed turbine, and it was found that the selected aluminum alloy is suitable for the designed turbine. However, the reliability of the preliminary design algorithms and numerical methods should be strictly verified by an actual experimental test.
Effect of graphene oxide on mechanical characteristics of polyurethane foam
Kim, Jong-Min ; Kim, Jeong-Hyeon ; Choe, Young-Rak ; Park, Sung Kyun ; Park, Kang Hyun ; Lee, Jae-Myung ;
Journal of the Korean Society of Marine Engineering, volume 40, issue 6, 2016, Pages 493~498
DOI : 10.5916/jkosme.2016.40.6.493
In the present study, graphene oxide based polyurethane foams were manufactured as a part of the development process of mechanically strengthened polyurethane foam insulation material. This material is used in a liquefied natural gas carrier cargo containment system. The temperature of the containment system is
. First, graphene oxide was synthesized using the Hummers' method, and it was supplemented into polyol-isocyanate reagent by considering a different amount of graphene oxide weight percent. Then, a bulk form of graphene-oxide-polyurethane foam was manufactured. In order to investigate the cell stability of the graphene-oxide-polyurethane foam, its microstructural morphology was observed, and the effect of graphene oxide on microstructure of the polyurethane foam was investigated. In addition, the compressive strength of graphene-oxide-polyurethane foam was measured at ambient and cryogenic temperatures. The cryogenic tests were conducted in a cryogenic chamber equipped with universal testing machine to investigate mechanical and failure characteristics of the graphene-oxide-polyurethane foam. The results revealed that the additions of graphene oxide enhanced the mechanical characteristics of polyurethane foam. However, cell stability and mechanical strength of graphene-oxide-polyurethane foam decreased as the weight percent of graphene oxide was increased.
A study on the optimization of manufacturing processes of double wall bellows for dual fuel engine I - Design optimization by buckling and stress analysis -
Kim, Pyung-Su ; Kim, Jong-Do ;
Journal of the Korean Society of Marine Engineering, volume 40, issue 6, 2016, Pages 499~503
DOI : 10.5916/jkosme.2016.40.6.499
Dual fuel engines are suitable for stricter regulations as they significantly decrease exhaust gas output. Hence, research and development of double wall bellows for dual fuel engines is important. In this study, optimum forming methods and welding conditions were derived to develop double wall bellows made of austenite stainless steel. The reliability of the prototypes was ensured by various performance evaluations. In this study, the buckling load and bellows stress were obtained by structural design, buckling, and stress analysis to design optimum bellows. As a result, the buckling load in the embossing shape of bellows increased by approximately 1.6 times, and no buckling and squirming occurred at 30.0 bar, which was twice that of the maximum design pressure.
A study on the optimization of manufacturing processes of double wall bellows for dual fuel engine II - Optimization of welding process -
Kim, Pyung-Su ; Kim, Jong-Do ; Song, Moo-Keun ;
Journal of the Korean Society of Marine Engineering, volume 40, issue 6, 2016, Pages 504~509
DOI : 10.5916/jkosme.2016.40.6.504
Production processes of double wall bellows can be roughly categorized into two steps. In the first step, inner and outer bellows are made of STS316L in austenite stainless steel due to their excellent formability and corrosion resistance. In the second step, the double wall bellows are manufactured using the welding method with both the inner and outer bellows. The microstructure and defects of each weldment are observed to ensure the reliability of bellows since weldment is a highly vulnerable part, which can crack and fracture when bellows are formed or used. In this study, optimum welding conditions were derived from the analysis of microstructure and inspection of weldment of bellows that were produced using various welding procedure. Moreover, the mechanical properties were evaluated through hardness measurement of substrate, weldment and the heat-affected zone.
A study on the performance of the sacrificial anode used for cathodic protection of a marine bridge after 8 years
Jeong, Jin-A ; Ha, Ji-Myung ; Lee, Du-Young ; Lee, Sang-Deuk ;
Journal of the Korean Society of Marine Engineering, volume 40, issue 6, 2016, Pages 510~515
DOI : 10.5916/jkosme.2016.40.6.510
Recently, corrosion occurred on the piles of a marine bridge located on the NamHae expressway in Korea. A sacrificial anode cathodic protection system was installed to prevent corrosion damage in the marine bridge. In the case of the marine bridge in this study, the sacrificial anode cathodic protection system was applied at the tidal and splash zones of the piles because the upper part of the structure was not corroded, and because corrosion occurs at the tidal and splash zones due to sea tides. To verify the performance of the sacrificial anode cathodic protection system 8 years later, cathodic protection (CP) current, CP potential, and degree of depolarization were measured. The experimental results on the performance of the sacrificial anode cathodic protection system from a total of 60 piles were classified into 4 categories: good CP effect results (13 piles), partial CP effect results (27 piles), temporarily erroneous results (5 piles), and need for maintenance because of delamination (15 piles). It was determined that additional repairs are required, such as the application of bulk anodes and jacket casings, for piles where the CP effect is poor.
Development of hovering-type AUV test-bed 'OCTAGON'
Choi, Dong-Ho ; Lee, Young-Jin ; Hong, Sung-Min ; Kim, Joon-Young ;
Journal of the Korean Society of Marine Engineering, volume 40, issue 6, 2016, Pages 516~526
DOI : 10.5916/jkosme.2016.40.6.516
This paper introduces a hovering-type autonomous underwater vehicle (AUV) developed for research and its fundamental motion performance results obtained by simulation and field test. The AUV can control its motion in four degrees of freedom (DOF) by means of its horizontal and vertical thrusters, and it is designed to provide a test-bed that facilitates ease of operation and experimentation. Prior to the field tests, six DOF equations of motion are developed, and a simulation program is constructed using MATLAB and Simulink to verify the essential motion performance of the designed vehicle. Furthermore, a proportional-integral-derivative (PID) controller and fuzzy PID controller are designed, and their performances are verified through a simulation. Field tests are performed to verify the motion performance of the AUV; way-point tracking is executed by the PID and fuzzy PID controllers. The results confirmed appropriate control performance under current disturbances.
Design of a synchronization controller for non-rail mobile rack using repetitive control method
Kim, Hwan-Seong ; Park, Jin ; Ha, Yun-Su ;
Journal of the Korean Society of Marine Engineering, volume 40, issue 6, 2016, Pages 527~534
DOI : 10.5916/jkosme.2016.40.6.527
The non-rail mobile rack, which is used for cargo storage, can improve the storage capacities of logistics centers. Furthermore, it has the advantage that it can be used in traditional logistics centers without making any changes or renovation, such as installing rails. However, when the rack is operated by separated drive actuators mounted on the left and the right wheels, precise position control of the wheels is necessary even if the unbalanced cargo weight on the rack would affect the control. Therefore, internal synchronization control for position tracking between the left and right wheels on the non-rail mobile rack is necessary in this study. In addition, external synchronization control for realizing the same straight movements between mobile racks is necessary. For the internal and the external synchronization control, we propose a synchronization control algorithm based on the repetitive control theory. An internal synchronization control algorithm with repetitive control theory requires the application of the robust servo control method owing to parameter variations. In this case, we can set up the gains for the robust servo control system by considering the cargo variations on the mobile rack. Furthermore, for developing the external synchronization control algorithm, we use a double repetitive control system to perform synchronization control between mobile racks. The efficiency of the proposed control algorithm will be verified by simulation and experimental results. The proposed algorithm can be easily applied in the industry.
A study on efficient integration model of satellite and underwater communication for improving throughput efficiency
Baek, Chang-Uk ; Jung, Ji-Won ;
Journal of the Korean Society of Marine Engineering, volume 40, issue 6, 2016, Pages 535~541
DOI : 10.5916/jkosme.2016.40.6.535
In this paper, we analyzed efficient decoding scheme with FTN(Faster than Nyquist) method that is transmission method faster than Nyquist theory and increase the throughput. Applying the FTN method to satellite and underwater communication, we proposed an efficient transceiver model. To minimize ISI(Inter-Symbol Interference) induced by FTN signal, turbo equalization algorithms that iteratively exchange probabilistic information between Viterbi equalizer based on BCJR algorithm and LDPC decoder are used in satellite communication. In others, for underwater communication, DFE equalizer and LDPC decoder are concatenated to improve performance.
Internet of things application service system with open source hardware
Seong, Chang-Gyu ; Rhyu, Keel-Soo ;
Journal of the Korean Society of Marine Engineering, volume 40, issue 6, 2016, Pages 542~547
DOI : 10.5916/jkosme.2016.40.6.542
In recent times, Internet of Things (IoT) has attracted wide attention, and there are increasing requests for IoT application services. Open-Source Hardware (OSH) utilizes a variety of components that are created through the sharing of hardware design so that others developers can also work on it. The concept of "open source" that attracted attention in the software industry has been applied to the hardware field by the emergence of IoT market. The emergence of OSH that has the advantage of low hardware cost and faster development encourages the idea of a diverse IoT application services. In this paper, we describe an IoT application service system that is developed using the OSH platform Arduino and Raspberry Pi to process collection, exchange, and computation of the environmental information. The overall system architecture and hardware and software components are presented.