• 유체기계공업학회:학술대회논문집
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• 2005.12a
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• pp.582-588
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• 2005

An experimental study to establish a standard of sump model test of pump station was implemented. Comparison of foreign standard was also performed. Configuration condition around a bell mouth suction intake was easily adjusted by 3-axis traversing system and partition allocation. Operational condition was also varied widely to give accurate test data. PIV was also introduced to produce Quantitative analysis of flow field such as free-surface vortex and submerged vortex occurring in the model test. More detailed vortex behaviors were represented by PIV analysis.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.201.2-201.2
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• 2011

A water-source heat pump system has been developed for cooling and heating of a green house on the waterfront in Jinju. In order to supply a heat source/sink of water in alluvium aquifer to the heat pump system, the riverbank filtration facility (two pumping wells and one recharge well) for water intake and injection has been constructed. To pump and recharge water sufficiently, the geometric design such as depth and diameter for the wells have been completed, and details of the well such as slot size and length of the screen and filter pack size have been designed based on the practical and theoretical design method including D30 technique. For the investigation of the hydrogeological characteristics, step-drawdown test, long-term pumping test, and recovery test have been carried out for two developed pumping wells. Step-drawdown test has been performed on 4 step flowrates of 150, 300, 450, $600m^3$/day for 1 hour, and long-term pumping test on flowrate of $500m^3$/day for 24 hours, and recovery test for 6 hours. Since the underground water filtrated by riverbank is flowing smoothly into the well, the water level goes down slightly for the long-term test. Consequently, the stable pumping flowrate for two pumping well has been predicted at least over $1,647m^3$/day which is larger than the flowrate of $1,000m^3$/day for a 60 RT heat pump system.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.1160-1164
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• 2017

In this research, a high altitude simulating test facility is designed using vacuum pump system composed of roots pumps and screw pumps. Air flow rate and chamber pressure are 1 kg/s and 2500 Pa, respectively. To design the test facility, experimental tests using certain pump combinations are performed for air injection of the order of hundreds of g/s. From the tests, it is found that 11 roots pumps and 33 screw pumps are required for the considered test facility. Test results are compared with theoretically estimated values. However, intake capacity theoretically estimated is found to be 20 percent larger than test results. This is thought because of higher pressure difference of roots pump for test conditions. Therefore, if more screw pumps are added for the considered pump system, it would be possible to lower the vacuum level of test chamber.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.10
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• pp.83-92
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• 2019

A pump is considered to be submersible when a motor and a pump are integrated and operate while submerged in water. Submersible pumps mainly function as rejection pumps to prevent foods in densely populated areas, as cold water circulation pumps in large power plants, as pumps to supply irrigation water, as drainage pumps to prevent flooding of agricultural lands, as water supply intake pumps, and as inflow pumps for sewage treatment. The flow in such turbomachines (submersible pumps) inevitably involves various eddy currents. Since it is almost impossible to accurately grasp the complex three-dimensional flow structure and characteristics of a rotating turbomachine through actual testing, three-dimensional numerical analysis using computational fluid dynamics techniques measuring the flow field, velocity, and the pressure can be accurately predicted. In this study, the shape of the impeller was developed to reduce vibration and noise. This was done by increasing the efficiency of the existing submersible pump and reducing turbulence. In order to evaluate the pump's efficiency and turbulence reduction, we tried to analyze the flow using ANSYS Fluent V15.0, a commercial finite element analysis program. The results show that the efficiency of the pump was improved by 4.24% and the Reynolds number was reduced by 15.6%. The performance of a developed pump with reduced turbulence, vibration, and noise was confirmed.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.5
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• pp.78-85
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• 2000

This study is to develop the diesel engine which has 6 cylinder natural aspiration direct injection type of 7.4$\ell$ with high performance, low emissions and low fuel consumption Finally the developed engine meets Korean `98 exhaust emission regulation for the city bus of heavy duty diesel engine by optimizing the various combustion parameters affecting performance and exhaust emissions. Combustion parameters are the swirl ratio of intake ports, the profile of injection pump`s cam affecting injection pressure, the design features of piston bowl of injection pump`s cam affecting injection pressure, the design features of piston bowl of combustion chamber and injector`s hole size. Through experimental analysis, various combustion parameters are optimized and the results are as follows; the swirl ratio is 2.20, the profile of injection pump`s cam is concave and re-entrant ratio, inner diameter of piston bowl and hole diameter of injector is 0.88,$\psi$64.0mm and $\psi$0.25mm respectively.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.26 no.11
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• pp.529-534
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• 2014

This research developed a hybrid heat pump system with the functions of dehumidification and heating, which uses simulated air that is like underground air, from an environmental chamber as a heat source. The system consisted of three evaporators and three condensers that were installed in series in the air passage, between the underground and load space. As results, the total amount of dehumidification was 2.726 kg/h, and the heating $COP_h$ was 1.84 at air intake temperature $17^{\circ}C$ and relative humidity 70%, which is a similar condition to underground air. We found that the total amount of dehumidification also increased with the air temperature and humidity. The system $COP_s$ was reached at 2.5, if we include the latent heat of dehumidification in the conventional heat pump system's COP.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.10 no.4
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• pp.304-315
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• 1981

This paper presents, the result of the study for the fluctuant temperature of the out-side air adopting the heat pump system in seoul, Taejean, Taegu, Busan and Jejeu among principle cities in korea for the purpose of checking the heating capacity, Heat pump capacity (outlet capacity), Coefficient of performance and running cost in comparison with the supporting the energy for the boiler's operation. According to the supply temperature changes of the out door coil by the out side air-return air mixing ratio, the Coefficient of performance is increased from 3. 1 to 5.0. Particularly, in Taegu, it is necessary to adopt the heat pump system against the supplement heat supply on the full outside air intake in January of the heating period, and it was recognized that the running cost is cheaper than that of the Boiler use. At the same time, if it is able to get $25\%$ of return air of the inside in the Seoul, it could be saved its costs when we use the supplementary boiler. And I think it is necessary to the development.

• Journal of Advanced Marine Engineering and Technology
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• v.41 no.1
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• pp.31-35
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• 2017

The internal flow of a pump system that is installed in the interior of large vessels such as tankers is largely affected by the water level and flow conditions of the pump sump. However, the performance of the pump is generally evaluated with the consideration of only the performance of the pump itself, without considering the pumping station operating environment. Therefore, if the pump is affected by the incoming flow that exhibits vortex and swirl, the occurrence of vortex and swirl accompanied with air may cause problems with the pump sump. This effect of flow condition can lead to a decrease in efficiency, increase in vibration, and noise generation in the pump. In this study, to investigate the internal flow of the pump sump according to several water levels, a pump sump scale-model was designed and constructed. The frequency of vortex occurrence and the shape of the vortex were investigated according to the different water levels of a fundamental test. The Class C vortex type, which has a larger volume of air intake to the pump, was confirmed by the higher occurrence frequency at a relatively lower water level.

• Journal of the Korean Society of Mechanical Technology
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• v.20 no.6
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• pp.917-923
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• 2018

The drinking water supply system applicable to the laying hen consists of air-water heat pumps, drinking water tanks, heat stroage tank, circulation pumps, PE pipes, nipples, and control panels. When the heat pump system has power of 7.7 to 8.7 kW per hour, the performance coefficient is between 3.1 and 3.5. The supply temperature from the heat pump to the heat stroage tank was stabilized at about $12{\pm}1^{\circ}C$, but the return temperature showed a variation of from 8 to $14^{\circ}C$. Stratified temperature in the storage tank appeared at $12.^{\circ}C$, $13.5^{\circ}C$ and $14.4^{\circ}C$, respectively. The drinking water supply temperature remained set at $15^{\circ}C$ and $25^{\circ}C$, and the conventional tap water showed a variation for $23^{\circ}C$ to $30^{\circ}C$. As chickens grow older, the amount of food intake and drinking water increased. $y=-0.0563x^2+4.7383x+8.743$, $R^2=0.98$ and the feed intake showed $y=-0.1013x^2+8.5611x$. In the future, further studies will need to figure out the cooling effect on heat stress of livestock.

• Journal of the Korean Society of Visualization
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• v.9 no.4
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• pp.74-79
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• 2011

In this study the change of free surface vortex is represented at different times according to height of water and with or without curtain wall installation. The air volume fraction is investigated at each condition of water level and the influence about creation of vortex is analyzed. The height of sump intake is taken as 100mm and the water level is divided into 5 steps. The sump model is the TSJ model and the curtain wall is applied by HI standard of America. The results shows that the free surface vortex can be identified on the isotropic surface at air volume fraction 1%~5% and the vortices make an air column from the free surface to the sump intake and are created and destroyed repeatedly. In the higher water level, less air is absorbed into the intake pipe. After curtain wall installation, the suction rate of the air volume fraction is decreased by 6.7%. The result of the vortex motion according to time, works on a cycle.