• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.13 no.1
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• pp.1-6
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• 2017

In this paper, the flow characteristics of water in the water supply pipes of a WBC array were evaluated. We simulated the flow velocities and pressures for a standard pipe, an expansion pipe with a concentric reducer, and an expansion pipe with an eccentric reducer using computational fluid dynamics. In the case of the standard pipe, when the inlet flow velocities were 0.5 m/s and 2.0 m/s, the maximum flow velocities at the center of the WBC array were 0.54 m/s and 2.74 m/s, respectively, which were the greatest values among those of all the pipe models considered. In the case of the expansion pipe, the maximum flow velocities at the center of the WBC array were almost the same under the same conditions regardless of the type of reducer. The pressure losses in the pipe due to the concentric and eccentric reducers were found to be (165.09 ${\times}$ inlet $velocity^{1.6677}$) and (210.98 ${\times}$ inlet $velocity^{1.6478}$), respectively. The coefficient of determination at this time was greater than 0.99 and was the same for both the models. As a simulation result, it was found that in order to reduce the pressure loss when pipe with WBC array is connected with a conventional pipe, diameter of the pipe with WBC array at that section should be enlarged by one step, and then connected to the conventional pipe with a concentric reducer.

• Journal of the Korea Safety Management & Science
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• v.17 no.4
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• pp.161-169
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• 2015

A fire sprinkler system is very important to extinguish fire in the building. The sprinkler system initiates sprinkler discharge if the detection system identifies a developing fire and opens the pre-action valve. However, pre-action fire sprinkler systems mainly installed in the underground parking lot at the apartment complex do not properly operate at fire if the connection type of fire sprinkler systems does not properly installed and operated. This study identified the relationship between fire dispersion & damage and the connection type of water supply in the sprinkler system from many fire cases at the apartment complex in South Korea. In addition, this study also identified the water supply differences and characteristics between South Korea and foreign countries. The main purpose of this study is also to improve the water connection types in the sprinkler system that can reduce the potential failures of pre-action valve operation through electrical signal system. The study also suggests the improvement plan for water connection types in pre-action fire sprinkler system that can minimize potential failure of pre-action fire sprinkler system. The suggestions for revising the fire safe standard in South Korea includes letting the water supply pipe of sprinkler system water inlet connect to the second side of pre-action valve and the water flow device that can minimize potential failure of sprinkler system.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.10a
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• pp.347-352
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• 2003

This study attempts to develop the management and control system of water pipe on the footing of database builded by the research on the pipe of water supply equipped over 48.809km within district of Hamyang-up by Hamyang-Gun, and to apply it to the work of self-governing body. And, since the structure and equipment of facilities of underground water supply pipe ate so complex, the maintenance and management of function of facilities are needed for long-term. This study has the purpose to build the database per self-governing body which can be connected with the future NGIS project, and to promote the efficiency of management and control of facilities and equipment.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 1991.09a
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• pp.41-47
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• 1991

This study reports the results of the transient temperature response of a floor heating panel according to variation of the hot water supply temperature and the pipe embedding depth. Also, this experiment compares the temperature responses of floor heating panels under the continuous and intermittent heating system. Furtthermore, this study presents some details of the thermal response of Ondol-heated buildings to varying loads and patterns of heat input. The analysis of the thermal performance fo Ondol heating system have been presented.

• Journal of the Korean GEO-environmental Society
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• v.9 no.3
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• pp.11-15
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• 2008

By considering manufacture and economic factor, the steel pipes have been employed for water supply pipeline with large diameter. The standard to decide a thickness of pipe was provided by the waterworks standard (Ministry of Construction & Transportation, 1992) in South Korea. However, there was no the systematic standard to confirm a thickness of pipe in it. Thus, it should be able to apply to unsuitable the Stewart formula for the buried pipe to design for an optimum thickness of pipe. In order to meet revised the waterworks standard (The Ministry of Environment, 1997), it has been considered both the ground condition and all of the stresses to compute a thickness of pipe. As a results, a method is suggested to determine thickness of pipe after comparing and validating the obtained results with the established results from the Stewart formula.

• Journal of Korean Society of Water and Wastewater
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• v.28 no.6
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• pp.699-711
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• 2014

This study was carried out to analyze water suspension in the water supply system through fault tree analysis. And quantitative factors was evaluated to minimize water suspension. Consequently the aim of this study is to build optimal planning by analyzing scenarios for water suspension. Accordingly the fault tree model makes it possible to estimate risks for water suspension, current risks is $92.23m^3/day$. The result of scenario analysis by pipe replacement, risks for water suspension was reduced $7.02m^3/day$ when replacing WD4 pipe. As a result of scenario analysis by water district connections, the amount of risk reduction is maximized when it is connecting to network pipe of D Zone. Therefore, connecting to network pipe for D Zone would be optimal to reduce risk for water suspension.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.10a
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• pp.380-384
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• 2010

A disturbance flow at piping bands and discontinuous regions such as a valve, a header has a intense broadband internal pressure field and a sound field which are propagated through the piping system The fields becomes the source of a vibration of this piping system. Intense broadband disturbance flow at a discontinuous region such as elbows, valves or headers generates an acoustical pulsation. The pulsation becomes the source of structural vibration at the piping system. If it coincides with the natural frequency of the pipe system, excessive vibration results. High-level vibration due to the pressure pulsation affects the reliability of the plant piping system. This paper discusses the high vibration and the branch vent pipe's failure of condensate-water supply piping system due to the effect of acoustical pulsations by flow turbulence from the flow control valves of globe type in a power site.

• Composites Research
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• v.22 no.3
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• pp.1-8
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• 2009

In this paper, we present the results of experimental and analytical investigations on the structural behavior of GFRP pipes used in the water supply pipeline system. Cross-section of the pipe is consisted with two GFRP tubes and polymer mortar between the tubes. Due to the advantages such as light-weight, corrosion resistance, smooth surface, flexibility, etc., use of GFRP pipe in the water supply pipeline system is ever increasing trend. Therefore, more optimized structural design methodology should be developed. In the investigation, we conducted theoretical and analytical studies on the load versus radial deformation characteristics of GFRP pipes. In addition, ring stiffness test is also performed. Test results are compared with theoretical and analytical results and it was found that the results are agreed well within 5% of radial deformation. Finally, it was also found that the GFRP pipes used in the water supply pipeline system are strong enough to satisfy the industrial requirements.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.453-458
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• 2008

Pump of high lift use to development of a technological level according as a building grow big. Water-Hammer to increase by valve of fast to closing agreeably to pipe laying to accept electronic valve, because by a damage of piping-system and the devil knows injury of vibration. Water-Hammer take a low effect to various method for solve. A New type manufacture develop and testing of pipe line to same to axis use to accumulator for water-Hammer to low effect and liner control of pressure. Impact-pressure of absorption ability and confirmation to decrease of vibration level through to preexistence manufactures and comparative test. Water-hammer and pipe vibration make low of piping system.

• The KSFM Journal of Fluid Machinery
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• v.12 no.5
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• pp.19-24
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• 2009

This paper is performed to find out the stability of water-hammer in pipe line and pump station that is happened when additional water needs demanded. At first, the water supply construction project is planned to supply $6,000\;m^3/day$ through 17.9 km pipe line. But additional demand ($1,200\;m^3/day$) happened from Cheong-ra water reservoir. In this situation, air-chamber($4\;m^3$) and vacuum breaker valve(${\varphi}100\;mm$) are needed to prevent water-hammer. When the additional water is supplied, the existing facilities (air-chamber, vacuum breaker valve) are sufficient to alleviate shock not changing capacity alteration, judging from the airspace change and rise. Therefore, there is no problem for water-hammer by installing air-chamber($4\;m^3$) and vacuum breaker valve(${\varphi}100\;mm$) at the top of Yeo-ju hill.