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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of the Korea Society For Power System Engineering
Journal Basic Information
Journal DOI :
The Korea Society for Power System Engineering
Editor in Chief :
Volume & Issues
Volume 12, Issue 6 - Dec 2008
Volume 12, Issue 5 - Oct 2008
Volume 12, Issue 4 - Aug 2008
Volume 12, Issue 3 - Jun 2008
Volume 12, Issue 2 - Apr 2008
Volume 12, Issue 1 - Feb 2008
Selecting the target year
Study on the Gas-Liquid Mixing System by Using Ejector
Jin, Zhen-Hua ; Kim, Pil-Hwan ; Park, Gi-Tae ; Chung, Han-Shik ; Jeong, Hyo-Min ;
Journal of the Korea Society For Power System Engineering, volume 12, issue 3, 2008, Pages 5~11
Study on K-factor for temperature variation of working fluid in spray nozzle with orifice
Bae, K.Y. ; Chung, H.T. ; Kim, C.H. ; Kim, H.B. ;
Journal of the Korea Society For Power System Engineering, volume 12, issue 3, 2008, Pages 12~18
In the present study, the numerical simulation has been performed to investigate K-factor for temperature variation of working fluid in spray nozzle with orifice. The commercial CFD software, Fluent with the proper modeling was applied for analyzing the internal of the spray nozzle. Numerical result for K-factor at
agrees with the experimental result that it applied n=0.5 within about 7% error. The pressure drop inside nozzle is showed 20% passing swirler, 70% in the region between the outlet of swirler and the orifice and 10% at the outlet of orifice. As the operating pressure is increased, K-factor is decreased by effect of flow resistance at it's inlet before pass swirler. The temperature increase of working fluid reduced the flow rate according to reducing of density, and average 1.23% decrease is showed in the present research.
Condensing Heat Transfer of Natural Refrigerants with Nanoparticles in Enhanced Tube
Lee, H.S. ;
Journal of the Korea Society For Power System Engineering, volume 12, issue 3, 2008, Pages 19~25
This paper deals with the heat transfer and pressure drop characteristics of R-290 (Propane), R-600a (Iso-butane) and R-1270 (Propylene) as an environment friendly refrigerant and R-22 as a HCFC's refrigerant for condensing. The test section is a horizontal double pipe heat exchanger. Condensing heat transfer and pressure drop measurements were Peformed for 12.70 mm micro-fin tube and compared with the results in smooth tube. The local condensing heat transfer coefficients of hydrocarbon refrigerants were superior to those of R-22 and the maximum increasing rate of heat transfer coefficient was found in R-600a. The average condensing heat transfer coefficients in hydrocarbon refrigerants showed 20 to 28% higher values than those of R-22. Hydrocarbon refrigerants have a higher pressure drop than that of R-22 with respect to refrigerant qualify and mass flux. Also, the condensing heat transfer coefficient and pressure drop of working fluids in smooth and micro-fin tube were compared. The heat transfer enhancement factor (EF) between smooth and micro-fin tube varied from 2.2 to 2.6 in all experimental conditions.
Heat Transfer and Friction Factors in the Channel with an Inclined Square Diamond Type Perforated Baffle
Oh, S.K. ; Putra, A.B.K. ; Ahn, S.W. ;
Journal of the Korea Society For Power System Engineering, volume 12, issue 3, 2008, Pages 26~31
This experimental study investigates the local heat transfer enhancement characteristics and the associated frictional head loss in the rectangular channel with a single inclined baffle. Four different types of the baffle are used. The inclined baffles have the width of 19.8 cm, the square diamond of
, and the inclination angle of 5o, and number of holes of up to 9. Reynolds number is varied between 23,000 and 57,000. Results show that the heat transfer and friction factor depend significantly on the number of baffle holes and Reynolds number. The friction factor decreases with increasing Reynolds number and the number of holes on the baffle. It is found that the heat transfer performance of baffle type II(3 hole baffle) has the best values.
Investigation of Pressure drop on shell side of shell and tube heat exchanger
Lee, Y.B. ; Han, S.G. ; Ko, J.M. ;
Journal of the Korea Society For Power System Engineering, volume 12, issue 3, 2008, Pages 32~37
The present work aims to determine the overall pressure losses in the shell from the point of entry of the fluid to the outlet point of fluid of shell and tube heat exchanger. The main contribution of the present work is concerned with calculating the pressure drop in the interior section and window section. Shell-side flow velocity distributions have been evaluated. We assume that the shell-side fluid is turbulent. The calculation procedure is based upon the Delaware method. Evaluation of pressure drop on the shell side will be helpful for a designer or manufacturer of a heat exchanger.
Design of Speed-Variable Driving System and Tester for Electric Forklift Truck
Shim, J.H. ; Kang, H.K. ; Ham, S.H. ; Oh, S.H. ;
Journal of the Korea Society For Power System Engineering, volume 12, issue 3, 2008, Pages 38~43
The usage of electric forklift truck is gradually increasing due to the convenience at conveying and arranging the materials in the industrial field. In this study, the author designed and suggested the optimum driving system and load tester which both of them are the most important part of the forklift truck. The planetary gear is chose to driving system because it makes big power even though the motor size is small. The gear teeth of planetary gear were designed and the designed planetary gear was tested considering the yield strength and the abrasion of gear teeth. The B-Type electric brake which consists of multiple plates and operates with non-magnetic type was connected with a single shaft in the driving system. So, it can be applied at the sudden braking situation which has the torque increment. And it has the compact size and excellent durability Load tester can give the various levels of load to the planetary gear of driving system in the electric forklift truck and it can also measure the levels of the load which were applied. Therefore, we can measure the noise, torque and perform the durability, vibration tests using load tester. It will be economical because many kinds of test can be performed using reasonable priced load tester The driving system of electric forklift truck which has sufficient competitive can be manufactured using our designed planetary gear reducer with reasonable price. The designed load tester can use for checking the performance of other reducers, as well.
A Study on Wear loss of Motorcycle Brake Disk by Response Surface Method
Jeon, H.Y. ;
Journal of the Korea Society For Power System Engineering, volume 12, issue 3, 2008, Pages 44~49
In this research, I would like to choose sliding distance and ventilated hole number which affect to the amount of wear of disk and pad as experiment conditions of 'the amount of wear' through wear test of motorcycle brake disk. Also, I analyze the amount of wear according to the variation of coefficient of friction by using design of experiment that is being widely used in diverse areas. With the tests of least, I present the correlation of each experiment condition. Therefore, I analyzed the variation of the amount of wear of disk and pad according to test factors such as ventilated hole number, applied load, sliding speed, and sliding distance in wear test of motorcycle brake disk by applying the design of experiment. Also, I analyzed quantitatively the influence of test factors through Taguchi Robust experimental design, response surface and examined the most suitable level and estimation of the amount of wear of disk. From these, I reached the following conclusions. response surface design, mathematical model was constructed about amount of wear of disk and pad. The amount of wear that decrease according to increase of ventilated hole number, and it's increase according to Increase of applied load, sliding speed, and sliding distance.
Characteristics of Sialon ceramics by Kinds of Additive
Park, S.W. ; Moon, S.J. ; Ahn, S.H. ; Kim, J.S. ; Nam, K.W. ;
Journal of the Korea Society For Power System Engineering, volume 12, issue 3, 2008, Pages 50~54
Various Sialon ceramics were fabricated by hot-pressing mixtures of
. The polished specimen of SiAlON
went on increasing in strength by heat treatment, heat treated non-polished specimen were similar or up to polished specimen in strength. The polished specimen of both SiAlON IV and V showed a very high strength, but were not Increasing of strength by heat treatment. All specimens were fractured on the surface and at the inner flaws. Surface fractures were initiated from the polished surface flaw and corner flaw. Inner fractures were initiated from an internal defect.
A study on the Polymer surface treatment of GF-filter bag for collection of fine Particle like carbon black
Lee, B. ; Choi, H.L. ; Moon, C.K. ;
Journal of the Korea Society For Power System Engineering, volume 12, issue 3, 2008, Pages 55~59
In this paper, we have investigated on collection efficiency of fine particle of glass fiber-filter bag according to the surface treatment. The solution consisted of polytetrafluoroethylene(teflon), graphite powder, silicon resin and water was used as a basic surface treatment agent. Tensile strength of glass filter-bag increased with up to 3hrs and then decreased with surface treatment time. Tensile strength and initial modulus of the glass fiber-filter bag treated by iodine after basic surface treatment for 3hrs were lower than those of basic surface treatment for 3hrs, however collection efficiency and fracture strain were higher than those of basic surface treatment for 3hrs. Glass fiber-filter bag with lower initial modulus and more strain will be extend the durable period and the one treated by iodine after basic surface treatment 3or 3hrs is expected high collection efficiency of fine particle. This method makes it possible to manufacture glass fiber-filter bag of the optimum condition.
Wear Properties of Thermal Sprayed Al-based Metal Matrix Composites Against Different Counterparts
Kim, K.T. ; Kim, Y.S. ;
Journal of the Korea Society For Power System Engineering, volume 12, issue 3, 2008, Pages 60~65
This study aims at investigating the wear properties of thermally sprayed
metal matrix composite(MMC) coating against different counterparts.
MMC coatings were fabricated using a flame spray system on an Al 6061 substrate. Dry sliding wear tests were performed using the sliding speeds of 0.2m/s and the applied loads of 1 and 2 N. AISI 52100,
balls(diameter: 8mm) were used as counterpart materials. Wear properties of
MMC coatings were analyzed using a scanning electron microscope(SEM) and energy dispersive X-ray spectroscopy (EDX). It was revealed that wear properties of
composite coatings were much influenced by counterpart materials. In the case of AISI 52100 used as counterparts, the wear rate of composites coating layer increased according to the increase of the applied load. On the contrary, in the case of ceramics used as counterparts, the wear rate of composites coating layer decreased according to the increase of the applied load.
Improvement of Cutting Performance of DLC Coated WC against Al Alloy
Lee, K.Y. ;
Journal of the Korea Society For Power System Engineering, volume 12, issue 3, 2008, Pages 66~71
Diamond-like-carbon (DLC) coatings could be good candidates as solid lubricants for cutting tools in dry machining of aluminum alloy. In this work, DLC thin films were produced as a friction reduction coating for WC-Co insert tip using the plasma immersion ion beam deposition (PIIED) technique. DLC coatings were also coated on
specimens and high temperature wear tested up to
in dry air to observe the survivability of the DLC coating in simulated severe cutting conditions using a pin-on-disc tribotester with Hertzian contact stress of 1.3GPa. It showed reduced friction coefficients of minimum 0.02 up to
. And cutting performance of DLC coated WC-Co insert tips to Al 6061 alloy were conducted in a high speed machining center. The main problems of built-up edge formation in aluminum machining are drastically reduced with improved surface roughness. The improvements were mainly related to the low friction coefficient of DLC to Al alloy and the anti-adhesion of Al alloy to WE due to the inertness of DLC.
Effect of Cu on the mechanical Properties and damping capacity of austempered ductile cast iron
Lee, K.H. ; Kang, C.Y. ;
Journal of the Korea Society For Power System Engineering, volume 12, issue 3, 2008, Pages 72~77
This study was investigated to know the effect of Cu addition on austempered ductile cast iron at various temperatures and times. Test results showed that the volume fraction of retained austenite and the carbon contents of retained austenite showed the greatest value at
. Also, in case of specimens having more Cu contents, the volume fraction of retained austenite and the carbon contents of retained austenite showed the lower value. After austempering treatment, tensile strength and Impact value increased, but elongation decreased. With increasing austempering treatment temperature, tensile strength, elongation, and impact value decreased. In case of specimen having more Cu contents, tensile strength showed the higher value, but elongation showed the lower value. Damping capacity was decreased by austempering treatment and was not affected on austempering temperature and time. In case of specimen having more Cu contents, damping capacity showed the higher value.