• KIEAE Journal
• /
• v.16 no.3
• /
• pp.95-101
• /
• 2016

Purpose: Recently, high-rise buildings are popular in korea due to high rate of land usage and cost performance in urban area. However, high-rise building causes several problems such as safety issues, cooling/heating load, stack effect, disaster prevention etc. The stack effect is one of the representative problems. Even though there are many researches on stack effect, there are few studies on design guideline considering local condition. Method: This study focuses on the change of pressure distribution according to the design factors which affects the airflow in high-rise residential buildings by simulation analysis. In this study, city, building floor, stairwell door leakage area, elevator door leakage area and changes of layout were considered ad the design factor. Result: The simulation results indicate that building height and ambient air temperature are significant design factor for stack effect.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.16 no.3
• /
• pp.24-29
• /
• 2017

In this study, a seat cross member was fabricated by optimizing the resin transfer molding processing of CFRP (Carbon Fiber Reinforced Plastics) materials. This seat cross member is used in automotive underbody parts and provides side impact support. The seat cross was manufactured via vacuum resin transfer molding. The process included 1min of resin injection, 8 mins of heating, and 1 min of cooling, for a total molding time of 10mins. Tensile test results showed an average breaking load of 21.50kN, a tensile strength of 404 MPa, and an elastic modulus of 46.2 GPa. As a result, the CFRP seat cross provides the same strength as a similar steel part, but weighs 42% less.

• Journal of the Korean Solar Energy Society
• /
• v.30 no.5
• /
• pp.32-37
• /
• 2010

In order to handle the crisis about energy-environment problem, it is necessary to develop the future-oriented and innovative energy technology in architecture area. So the development of new technology for energy saving and alternative energy use has been spurred in this area. Double skin window system, which is an active covering to respond to the exterior change of the environment, is the skill that can reduce the indoor cooling and heating load and the environmental architecture can be realized. This study works out U-value of windows using the window-simulation program with the development and study of the double skin. In addition, the effect of the double skin insulation on the efficiency rating has been analyzed, applying to the certification system of the building energy efficiency rating which has implemented.

• Proceedings of the SAREK Conference
• /
• 2009.06a
• /
• pp.108-113
• /
• 2009

Buildings with multi-complex spaces designed for architectural values and functional requirements give rise to technical challenges in terms of energy efficiency and thermal comfort. Since spaces in such buildings are connected with openings with geometrical complexity, it is hard to define zoning plan and to control heating/cooling loads effectively. This paper presents a case study on the evaluation of operation strategy for a building with multi-complex spaces using computer simulation. The modelling methodology and the results of the simulations are also described.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.23 no.7
• /
• pp.57-66
• /
• 2009

Microturbines system (MTS) are currently being deployed as small scale on-site distributed generators for microgrids and smart grids. In order to fully exploit DG potentialities, advanced integrated controls that include power electronics facilities, communication technologies and advanced modeling are required. Significant expectations are posed on gas microturbines that can be easily installed in large commercial and public buildings. Modeling, control, simulation of microturbine generator based distributed generation system in smart grid application of buildings for both grid-connected and islanding conditions are presented. It also incorporates modeling and simulation of MT with a speed control system of the MT-permanent magnet synchronous generator to keep the speed constant with load variation. Model and simulations are performed using MATLAB, Simulink and SimPowerSystem software package. The model is built from the dynamics of each part with their interconnections. This simplified model is a useful tool for studying the various operational aspects of MT and is also applicable with building cooling, heating and power (BCHP) systems

• International Journal of Naval Architecture and Ocean Engineering
• /
• v.4 no.4
• /
• pp.460-476
• /
• 2012

High-speed crafts suffer from losing a huge amount of their machinery energy in the form of heat loss with the exhaust gases. This will surely increase the annual operating cost of this type of ships and an adverse effect on the environment. This paper introduces a suggestion that may contribute to overcoming such problems. It presents the possibility of reusing the energy lost by the ships' exhaust gases as heating source for an absorption air condition unit onboard high-speed crafts. As a numerical example; the proposed method was investigated at a high-speed craft operating in Red Sea between Egypt and the Kingdom of Saudi Arabia. The results obtained are very satisfactory. It showed the possibility of providing the required ship's air condition cooling load during sailing and in port. Economically, this will reduce the annual ship's operating cost. Moreover, it will achieve a valuable reduction of ship's emissions.

• Journal of the Korean Solar Energy Society
• /
• v.26 no.1
• /
• pp.21-28
• /
• 2006

Changes in building construction methods and repairing of older buildings have reduced infiltration rate. Synthetic materials, release airborne particles and uneven healthy odor are increased. For preventing pollutants introduce fresh outdoor air into the building, simply letting fresh outdoor air into building, however, Is not a cost-effective way to ventilation. When additional ventilation is added to an existing HVAC system, the heating and cooling equipment, often cannot handle the increased load. A HRV provides a way to minimize in energy costs while introducing fresh air to a building. In this study, the economical research of HRV, made of three types of materials, are conducted. Heat recovering characteristics are studied at seasonal outdoor air conditions based on the outdoor air property condition at, Seoul in 2002. As a results, the average sensible effectiveness is 0.75 in the sensible heat exchanger and average total effectiveness is 0.65 in the total heat exchanger. The pay back period of the sensible heat exchangers are $3.2{\sim}3.5$ year and it of total heat exchanger is 2.2 years.

• Journal of the Korean Solar Energy Society
• /
• v.34 no.1
• /
• pp.64-71
• /
• 2014

This study is to perform economic analysis of a PVT-GSHP (Photovoltaic Thermal-Ground Source Heat Pump) system compared to the conventional system which consists of a boiler and a chiller. This research has simulated, developed and analyzed four systems for application in a residential and an office building which was based on the hourly EPI (Energy Performance Index, $kWh/m^2yr$). Case 1 includes a boiler and a chiller to meet heating and cooling demands for a house. Case 2 is the same conventional system as Case 1 for a office. Case 3 is simple summation of Case 1 and 2. And Case 4 is utilizing a PVT-GSHP to meet the combined loads of the house and office. The economic evaluation study was based on IEA ECBCS Annex 54 subtasks C economic assessment methods. This study indicated that PVT-GSHP system can save a building's energy up to 53.9%. Also the SPB (Simple Payback) of the PVT-GSHP system with 0%, 50% initial incentive was 14.5, 6.7 year respectively.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.24 no.4
• /
• pp.315-322
• /
• 2012

In these days, importance of HVAC system in office building is steadily growing in terms of thermal comfort and energy savings. As a energy efficient heating and cooling system, system air-conditioner which can be controlled distinctly and has a high COP is more widely adopted nowadays. However, the features and advantages of system air-conditioner were not reported well because system air-conditioner did not describe yet by conventional simulation methods such as TRNSYS, e-Quest, Energyplus, etc. In this study, by using the TRNSYS program which is able to show module implementation and building energy consumption analysis, system air-conditioner module will be proposed and validated through comparison between the simulation results and measurement results.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.19 no.5
• /
• pp.103-108
• /
• 2005

In this article, it has been shown that penises devices such as illumination facilities, heating/cooling systems and security equipment can be controlled even outside premises using UPnP (Universal Plug and Play) applicable to the Internet or cellular phone services. To load UPnP protocol into each device, current manufacturers will be required to port flexible OS (Operating System), that is, Windows or Linux to these premises devices. Furthermore, prospective users want to experience a variety of specific functions based on more standardized and stable network. This study aims to provide application by implementing these functions on the Linux system.