• Journal of the Korean Society of Marine Environment & Safety
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• v.18 no.3
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• pp.267-272
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• 2012

Carbon emission generated by energy issues is one of the major problems which all countries concern. The International Energy Agency recommends to improve 15-30[%] of energy efficiency than now. Government has pushed the domestic energy saving policies and incentives and penalties were also given in that direction. Pumps are widely used to transfer fluids and they consume at least 20[%] power of each nation. Their loss of energy is huge if they have been operated at low efficiency for long time. Low efficiency of these pumps is often due to incorrect design or degradation. Pump efficiency can be measured to estimate energy loss. If it is low, the pump may be repaired or replaced with new one. This paper introduces thermodynamic method to measure pump efficiency using only two kinds of sensors for temperature and pressure. It can calculate best efficiency point(BEP) of actual systems easily and fast. Its values were compared with the real performance curve provided by pump maker and we got almost similar performance curves from the repeated experiment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.8A
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• pp.735-744
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• 2006

In this paper, the optimum pump light powers of optical phase conjugator(OPC) are numerically investigated as a function of amplifier spacing in 1,200 km $8{\times}40$ Gbps WDM systems with 0.1, 0.4, 0.8, or 1.6 ps/nm/km dispersion coefficient. It is confirmed that the variation of optimal pump light power dependence on amplifier spacing for NRZ transmission system is smaller than that for RZ transmission system through the evaluations and analysis of eye opening penalty(EOP) characteristics. And, in both cases of NRZ and RZ transmission, the variation of optimal pump light power is more increased as amplifier spacing becomes longer. Additionally, it is confirmed that the best amplifier spacing in NRZ and RZ transmission system is 50 km.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.7
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• pp.105-113
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• 2022

In this study, a variable displacement swash plate pump supplying high-pressure hydraulic oil to control the hydraulic system of a marine engine was developed. A structural analysis was performed on the main parts of the pump to ensure the structural safety in the design. Using a pump testing equipment, performance characteristics such as no-load flow rate, load flow rate, flow rate according to the swivel angle change, flow rate with lubrication orifice, and response time according to the swivel motion were tested. Consequently, the pump was confirmed to satisfy the required specifications.

• 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 Advanced Marine Engineering and Technology
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• v.40 no.9
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• pp.756-761
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• 2016

The objective of this study is to design and manufacture a fuel pump with the plunger diameter of 4 mm and stroke of 7 mm that can be mounted in a small single-cylinder four-stroke agricultural diesel engine, and to investigate the performance characteristics of the pump. The combustion pressure in a cylinder was reproduced by forming the back pressure of 1, 6, 11, 16 and 21 bar with a nitrogen gas in the home-manufactured modeling cylinder. In the experiment, the discharge pressure was measured at the spot of 1 cm away from the discharge port of a developed fuel pump. The delivery pressure and delivery flow rate were measured at the spot of 30 cm away from the discharge port of the pump, and the pump efficiency was calculated. The pump motor speed was changed from 600 to 800, 1000, 1200 and 1400 rpm. It is found that the delivery feed rate of fuel pump is increased as the rotational speed is raised, and is decreased as the back pressure, compression pressure in the cylinder, is increased. Also, the pump efficiency is reduced as the rotational speed and back pressure are increased.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.4
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• pp.400-406
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• 2017

The model used in this study was reversed to analyze the cause of excessive damage that occurred inside the rotating system and pipe system of a centrifugal-type seawater pump on a ship. For this purpose, internal flow analysis on a cooling seawater pump was performed using CFD. As a result, the shape and boundary conditions of the target pump were set by reverse engineering, and pump efficiency at a design operating point of $125m^3/h$ was calculated as 85.3 % with a head of 32.0 m. The maximum efficiency point of the target pump was estimated to be 86.2 % at $150m^3/h$, but this differed from the actual operating point. At $112.5m^3/h$, which was the lowest flow point, flow was unstable due to the characteristics of the low flow point and analysis convergence was not good. The purpose of this study was to clarify the cause of ongoing cavitation in seawater pumps and piping systems in operation. Future research will be needed to clarify causes for pipe systems in the future by performing calculations for the total piping system of an inlet and outlet, in addition to measuring the flow rate of each branch pipe.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2011.10a
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• pp.85-85
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• 2011

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2012.06a
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• pp.269-269
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• 2012

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2012.06a
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• pp.243-244
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• 2012

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2012.06a
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• pp.236-236
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• 2012