• 한국태양에너지학회:학술대회논문집
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• 2009.11a
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• pp.80-85
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• 2009

Mathematical modeling and performance simulation results were shown for the solar thermal storage system which used heat pipe. The thermal storage system was composed of thermal storage tank and charging/discharging heat exchanger with one by the heat pipes. Heat pipe heat exchanger was attached to system, and could carry out charging and discharging to thermal storage tank at the same time. Height of the thermal storage tank was 600 mm, and that of the charging/discharging heat exchanger was 400 mm. Length of the heat pipe was the same as the total height of thermal storage system, and outer and inner diameter were 25.4 mm(O.D.) and 21.4 mm(I.D.) respectively. Diameter of the circular was 43 mm(O.D.), and fin geometries were considered as the design parameters. High temperature phase change material(PCM), $KNO_3$ and low temperature PCM, $LINO_3$ were charged to storage tank to adjust working temperature. Total size of thermal storage system able to get heat capacity more than 500 kW was calculated and the results were shown in this study. Number of heat pipe was required more than maximum 500, and total length of thermal storage system was calculated to the more than maximum 3 m at various condition.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.3
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• pp.206-210
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• 2015

The most important thing for NOVEC gas fire extinguishing equipment is to release NOVEC gas, which contained in the extinguishing container, to the safety section by the time appointed. For this matter, it is significant to decide arrangement and size of the proper piping equipment. This study has developed the design methodology of NOVEC gas fire extinguishing equipment in use of pipe network analysis techniques. Based on the design methodology, each design coefficient is chosen. It is found that the calculated result, which is 6.498 seconds, has been counted within the 10 seconds limit, which is fairly satisfied with extinguishing releasing time based on the developed methodology. At that time, the pressure loss is 21.09bar.

• Journal of computational fluids engineering
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• v.15 no.3
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• pp.66-72
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• 2010

The north and south panel of a geostationary satellite are used for radiator panels to reject internal heat and utilize several heat pipe networks to control the temperatures of units and the main structures of satellite within proper ranges. The design of these panels is very important and essential at the conceptual design and preliminary satellite design stage, so several thousands of nodes or more are utilized in order to perform detailed thermal analysis of panel. Generating a large number of panel nodes takes time and is tedious work because the nodes can be easily changed and updated by locations of units and heat pipes. Also the detailed panel model can not be integrated into spacecraft thermal model due to its node size and limitation of commercial satellite thermal analysis program. Thus development of a program was required to generate a detailed panel model, to perform thermal analysis and to make a reduced panel model for the integration to the satellite thermal model. This paper describes the development and the verification of the panel thermal analysis program with its main modules and functions.

• Journal of the Korean Solar Energy Society
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• v.36 no.3
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• pp.25-31
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• 2016

Gaskets are usually used for the sealing of flange joints. The joint is usually composed of two flanges, a ring gasket and clamping bolts. The metal ring gasket is suitable for pipe flanges, pumps and valve joints in high temperature and high pressure environments. A very high surface stress is developed between a ring type joint gasket and the flange groove when the ring type joint is bolted up in a flange. The dimensions of flanges and ring joint gaskets for the pipe sizes that are in common use are specified in the ANSI codes. However, sometimes it is necessary to make a new design for the flange joint which is not specified in the codes, as the equipment is getting larger and larger in size. This paper presents the contact behavior of Class 600 ring joint gaskets with oval and octagonal cross sections. Five different sizes of gaskets are employed in the analysis, and one of them is newly designed on the basis of analysis results obtained from existing models. Three load steps are used to find the stress, stain and contact pressure etc., and to compare the contact characteristics among the models due to the bolt clamping force and the working surface pressure. ANSYS Workbench version15 is used to conduct the finite element analysis.

• Transactions of the Korean Society of Automotive Engineers
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• v.25 no.1
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• pp.74-81
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• 2017

The door impact beam of the side-impacted vehicle plays a key role in securing occupant safety by preventing intrusion from the impacting vehicle. Despite the low production cost, the press door impact beam has been adopted sparingly because of the strength inferiority. In this study, the design technologies of the press beam aimed at improving bending strength were investigated. First, the effect of the section shape and size was examined. Next, thickness and material strength were increased. Also, the TRB beam application was simulated by varying combined thickness. Some TRB beams with reduced weight exhibited bending strength over the strength of the pipe beam. Then, the beam with a closed center section also showed remarkably enhanced maximum bending strength.

• The KSFM Journal of Fluid Machinery
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• v.14 no.5
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• pp.39-47
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• 2011

Flow control range of valve, which is installed on pipeline, varies according to valve type, pipe diameter, pipe length, roughness, and elevation difference of both ends of pipeline. A lot of computation efforts and knowledge are needed to estimate flow control range of valve, considering above many parameters. The table of flow control range of each valve type is presented for convenience of pipeline design engineers who must make decision of valve size and type in this study. Also the reason that butterfly valve is recommended for flow control, and gate valve is forbidden is presented via quantification and figures in this study.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.26 no.1
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• pp.38-41
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• 2014

Fixture units and the diversity curve are used, in order to determine the required size of water supply pipe. However, the values of the National Plumbing Code, International Plumbing Code and National Standard Plumbing Code of America are not the same. The objective of this study is to comparatively analyze the fixture units and the peak flows of a 10th story office building, at any instant of time, according to the three codes.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.5
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• pp.388-397
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• 2001

This paper addresses characteristics of compressible flow dynamics inside a pipe with an accumulator and an inlet orifice. It also presents a simple but stable numerical method associated with the accumulator-orifice calculation. In particular, a focus is given to developing a method of finding an optimum design of the accumulator-orifice system (i.e., the accumulator size and the throttle resistance) that gives the most effective dissipation of the water-hammering problem. It is found that there exists indeed an optimum set of parameter values for the most effective dissipation of the wave energy.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.12
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• pp.1107-1116
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• 2004

In this paper, the effects of diverse parameters on the operation of loop heat pipe (LHP), such as particle diameter of sintered porous wick, wick porosity, vapor line diameter, thickness of wick and heating capacity were investigated by a theoretical analysis. A LHP has a wick only in its evaporator for the circulation of working fluid, and utilizes a porous wick structure of which pore size is very small to obtain a large capillary force. The working fluid is water and the material of sintered porous wick is copper. For these different parameters, capillary pressure, pressure drop in wick, pressure drops and temperature distribution were analyzed by a theoretical design method of LHP.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.4
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• pp.9-14
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• 2019

Recently, container vessels are required to be applied various technologies to improve ship life-cycle and operating efficiency for the cost decreasing of logistics. The degradation of engine efficiency due to the increasing capacity of the ship and the related equipment of facilities are applied to large-scale ships without considering the condition of ship operation by increasing the ship size and feature. In this paper, the flow analysis is performed with existing gas pipe in large-scale container ship with the operation-condition of higher capacity engine and facilities, and the results were used on the new gas pipe design for ULCS (Ultra Large Container Ship). The newly designed gas pipe can be expected to increase the operating efficiency of ULCS.