• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.10 no.1
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• pp.7-13
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• 2014

This study intends to analyse the economical aspect of a GSHP(Ground Source Heat Pump) system compared to the conventional system which is consisted with a boiler and a chiller. This study has simulated four systems in Incheon. It developed and analyzed for applications in a residential and an office building which was based on the hourly EPI(Energy Performance Index, $kWh/m^2yr$). Case 1 is utilizing a boiler and a chiller to meet heating and cooling demand of a house. Case 2 is utilizing the same conventional set up as Case 1 of a office. Case 3 is summation of Case 1(house) and 2(office) systems and loads. And Case 4 is utilizing a GSHP to meet the combined loads of the house and office. The method of the economic assessment has been based on IEA ECBCS Annex 54 Subtask-C SPB(Simple Payback) method. The SPB calculated the economic balanced year of the alternative system over the reference system. The SPB of the alternative systems (GSHP) with 10%, 30% and 50% initial incentive has been calculated as 9.38, 6.72 and 4.06 year respectively while the SPB without initial incentive of systems was 10.71 year.

• Nuclear Engineering and Technology
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• v.36 no.3
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• pp.248-262
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• 2004

Turbulence models are separately assessed for a three dimensional thermal-hydraulic analysis of the integral reactor SMART. Seven models (mixing length, k-l, standard $k-{\epsilon},\;k-{\epsilon}-f{\mu},\;k-{\epsilon}-v2$, RRSM, and ERRSM) are investigated for flat plate channel flow, rotating channel flow, and square sectioned U-bend duct flow. The results of these models are compared to the DNS data and experiment data. The results are assessed in terms of many aspects such as economical efficiency, accuracy, theorization, and applicability. The standard $k-{\epsilon}$ model (high Reynolds model), the $k-{\epsilon}-v2$ model, and the ERRSM (low Reynolds models) are selected from the assessment results. The standard $k-{\epsilon}$ model using small grid numbers predicts the channel flow with higher accuracy in comparison with the other eddy viscosity models in the logarithmic layer. The elliptic-relaxation type models, $k-{\epsilon}-v2$, and ERRSM have the advantage of application to complex geometries and show good prediction for near wall flows.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.212-216
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• 2006

The purpose of this study is to obtain an effective enclosing method for noise reduction of press machine operating in a manufacturing company located in Korea. Noise level of the machine is about $90{\sim}105dB$ which is higher than legal standards by industrial safety and health law. This study has predicted the level of noise reduction according to a step by step prevention plan by considering the characteristics of the cause of noise, the permitted limit of noise levels, problems and economical efficiency attendant upon the noise prevention measures. The predicted level of noise at the plant in accordance with the first step is $71.5{\sim}89.5dB(A)$, and can satisfy the permitted limit of noise in a time period of the day. Based on these results, enclosing method adequate for the selected plant's noise characteristics were suggested.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.1465-1468
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• 2006

Railway is superior to the other land transportation systems in aspects of environmental problems. Environmental problems are not considered during a preliminary feasibility study. Investment for railway is low because of low B/C(benefit/cost)ratio in the economical efficiency analysis during the preliminary feasibility study. The body of this paper studies the railway noise which can reflect environmental problems an assessment of environmental impact. The body of this paper studies the presumption of The Benefit Cost of railroad noise arresting it will be able to reflect the evaluation environmental matter of the effect which it gives to an environment.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2057-2063
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• 2011

Recently, concrete slab track is mostly used to satisfy requirements for safety of high-speed train operation and economical efficiency of maintenance. Due to structural characteristics of ballast track structures, roadbeds under the ballast experience a state of high stress. In case of slab track structures, however, its roadbeds place on a condition of low stress less than roadbeds of ballast track structures as increasing of the loading area. In this study, vertical earth pressure under slab track structures was investigated through real-scale loading tests and theoretical analysis to compare with each other.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.2
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• pp.303-312
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• 2012

Water supply and sewerage systems are the large-scale urban infrastructure ejecting large amount of environmental load over the life-cycle. Therefore, it is important not only to optimize in the aspect of economical superiority and process efficiency but also to consider earth scale environmental impact. This study aimed to suggest the establishment of life cycle management(LCM) system as an integrated management solution in urban water supply and sewerage systems. As a result, the methodology for LCM system consisting of life cycle assessment(LCA), life cycle cost(LCC), life cycle $CO_{2}(LCCO_{2})$ and life cycle energy(LCE) was developed. Also, several case studies using the latest statistics data of water supply and sewerage systems were carried out to investigate the field applicability of LCM.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.656-661
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• 2009

In this study, theoretical analysis and evaluation tests were performed to assess the pipe stability against compaction equipments and vehicle loads when conventional construction criteria for pre-insulation heating pipes are applied and the alternative material, crushed sand, are used for backfills. The research outcomes shows that (1) the conventional code criteria for pre-insulated heating pipes is well established to support compaction equipments and vehicle loads, (2) the crushed sands as an alternative is usable as backfill materials for pre-insulated heating pipes based on the suitability evaluations of various types of pipes, and (3) the crushed sand agree well with the design consideration of pre-insulated heating pipes construction in the points of economical efficiency and construction criteria.

• 한국신재생에너지학회:학술대회논문집
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• 2008.10a
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• pp.347-348
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• 2008

Wind energy issued as most spotlight general energy by excellence of actuality as well as economical efficiency, solving environmental problem which caused by creating the energy and possibility of eternal production. Accordingly, government is at the stage of corresponding level by requesting development of new technology to the developed countries as a part of national key industries. The grievous situation from such a rapid movement is meteorological comprehension and assessment as well as the problem of estimation exactness about the wind. In this study, numerical simulation from the MM5 is counducted for 3km resolution and data assimilation using QuikSCAT seawinds data is applied.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.331-332
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• 2008

Wind energy issued as most spotlight general energy by excellence of actuality as well as economical efficiency, solving environmental problem which caused by creating the energy and possibility of eternal production. Accordingly, government is at the stage of corresponding level by requesting development of new technology to the developed countries as a part of national key industries. The grievous situation from such a rapid movement is meteorological comprehension and assessment as well as the problem of estimation exactness about the wind. In this study, we use the regional meteorological station data, automatic weather station data and QuikSCAT SeaWinds data.

• Journal of Energy Engineering
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• v.10 no.4
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• pp.327-334
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• 2001

Heat is wasted by unconcern in industrial complex. This paper presented for using waste heat, which investigated step by step from searching waste heat to starting construction before and directly applied for the using waste heat in the actual site. Especially, using heat is assessed by investigation of heat supply and demand. Design of heat transportation system was made base on analysis of heat balance between demand and supply, which was analyzed by economical efficiency and property. Payback-period on investment was 1,909 years that was comparatively a short period of time in assessment.