• Journal of ILASS-Korea
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• v.9 no.2
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• pp.18-23
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• 2004

An experimental studies of conventional gasoline fuel pump were carried out to obtain fundamental data fur liquid phase LPG injection(LPLi) system. A regenerative type and a roller-vane type of pumps were investigated in various operational condition. The experiments were performed to obtain flow rate of LPG fuel as a function of pressure differences and temperatures. The regenerative pump had too low flow rate at some experimental conditions to use this pump system for LPLi fuel supply system. On the other hand, the roller-vane type pump can be applied to the system only if its check valve is modified. Cavitation might occur in this system which can result in system noise, flow rate variation, and pump durability problem. To solve these problems the system is needed to increase $NPSH_{re}$(required net positive suction head).

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.11
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• pp.727-736
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• 2016

In this study, a high-pressure multistage pump used in the combined cycle power plants is analyzed. The pump performance characteristics (differential head and efficiency) are numerically analyzed for different shapes of the radial diffuser. The design variables selected for the radial diffuser are, number of vanes, diameter ratio ($D_4/D_3$), return channel outlet angle(${\alpha}_6$), and pressure recovery factor ($C_p$). The numerical analysis results showed that the differential head and efficiency are the highest when the diameter ratio is the highest. Further, it was observed that the differential head was lower when the return channel outlet angle was $60^{\circ}$ than when it was $90^{\circ}$, because of pre-swirl at the diffuser outlet.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.6
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• pp.2888-2897
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• 2011

The performance of a geothermal heat pump system using carbon dioxide was investigated by the steady-state cycle simulation program developed in this study. A parametric study was carried out in order to investigate the effect of various operating conditions on the performance of the basic cycle without an IHX(internal heat exchanger). The simulation program consists of several Fortran subroutines for simulating indoor and outdoor heat exchangers, compressors, and expansion valves and Visual Basic subroutines for the graphic user interface(GUI) consisted with pre-processor for input data and post-processor for the output data. Refprop V6.01 was used for estimating the thermodynamic properties and equilibrium behaviors of carbon dioxide. The simulation results were validated by comparing experimental data through a series of case studies. The cycle simulation program developed in this work would seem to be a useful tool in optimizing and establishing economical and efficient operating conditions in the $CO_2$ geothermal heat pump system.

• Tribology and Lubricants
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• v.5 no.2
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• pp.55-59
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• 1989

Measurement of the friction force of vane tip have been made to provide essential information for the study of the pump dynamics, the pump design and the analysis of triboligical problems in the sliding components. The influences of the radial load, rotating speed and frequency of vane on the friction forces of vane tip have been investigated. The results indicated that the friction coefficient of vane tip are affected by the rotating speed remarkably but the effect of acting load on the vane tip and frequency of load are very small. The stribecks diagram shows that the lubrication regime of the sliding point of vane tip is mixing lubrication.