• KIEAE Journal
• /
• v.15 no.5
• /
• pp.89-94
• /
• 2015

Purpose: Various policies to reduce the energy consumption have been carried out to save Earth environment against global warming and environmental pollution in many countries. Energy consumption of buildings in Korea has reached 24% of total energy consumption, and energy consumption of apartment has been continuously increasing. Therefore, Korea government has executed building energy efficiency rating certification system to control energy consumption of buildings. Method: This study was conducted to evaluate the energy performance of apartment unit plans according to the increasement of front width of unit plans, and tried to present the basic data to design more energy conscious unit plans for apartments. For the study, three shapes of unit plans -the 2Bay, 3Bay and 4bay unit- were selected for imput models. They were simulated using ECO2 software to assess building energy efficiency rating certification in Korea. Result: According to the results, in cases that balcony windows were not installed, the primary energy consumption of the 3Bay and 4Bay units were less than 2Bay unit, respectively, 0.1% and 2,5%. The primary energy consumption of the 3Bay and 4Bay units, in cases that balcony windows were installed, was less than 2Bay unit, respectively, 1.7% and 3.2%.

• Proceedings of the SAREK Conference
• /
• 2006.06a
• /
• pp.959-964
• /
• 2006

Recently, an international oil price shows fluctuation in 70 dollars per barrel and it is said that this trend is able to continues for much longer. Because energy consumption in buildings accounted for about 25% of the nation's total demand for energy, Energy censervation and efficiency of buildings were very important issues. Main political measures relating to building energy use and saving were 'the system of accrediting green building', 'building energy certification system', 'energy consumption efficiency rating indication system', 'building energy code', 'high efficient energy materials certification system'. This paper presents approaches to improve building energy efficiency policy.

• Journal of Navigation and Port Research
• /
• v.39 no.6
• /
• pp.465-472
• /
• 2015

SEEMP (Ship Energy Efficiency Management Plan) guidelines for a ship's GHG reduction include a machinery modification of hull, an installation of energy efficiency enhanced attachment in hardware methods. It is also possible to bring a ship energy efficiency improvement by fuel-efficient operations or in other software methods. Hardware modification or installation on ship can bring financial burdens to a ship company compared to its improvement expectation. On the other hand, Software based energy-saving technology can be applicable on various ship types, and it is also expected high efficiency of ship energy use compared to hardware based technology in perspective of the investment costs and efficiency. In this paper, it is described that the ship handling simulator based evaluation was carried out using representative ship model of bulk, container and VLCC. Simulation environments were separated into 6 conditions according to the sea-state and weather condition, and the operation results were compared with those before and after energy saving system applied The container ship showed the largest FOC save rate after energy saving system applied although the others also showed energy save rate after using the system.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2004.03a
• /
• pp.577-587
• /
• 2004

A coaxial pulsed plasma thruster (PPT) with a Teflon cavity was designed, and its performance characteristics were examined varying stored energy, cavity length and capacitance. The PPT was tested as the entire system including the discharge circuit, and the results were explained with both the transfer efficiency and the acceleration efficiency. The transfer efficiency is defined as the fraction of energy in capacitors supplied into plasma, and the acceleration efficiency as the fraction of energy supplied into plasma converted to thrust energy. To estimate these efficiencies, the equivalent plasma resistance was defined and calculated using energy conservation during discharge. The equivalent plasma resistance proportionally increased with cavity length, and therefore the current peak increased with decreasing cavity length. The energy density calculated by the transfer efficiency was increased with decreasing cavity length. As a result, higher acceleration efficiency and lower transfer efficiency were obtained with shorter cavity length. Accordingly, there was an optimal cavity length for the thrust efficiency. The specific impulse and the impulse bit per unit stored energy ranged from 390 s and 50 $\mu$ Ns/J for a cavity length of 34 mm to 825 s and 11 $\mu$ Ns/J for a cavity length of 4 mm when the stored energy was fixed to 21.4J. Thus, it was showed that the performance of this PPT approached that of electromagnetic-acceleration-type PPT with decreasing cavity length. The PPT achieved thrust efficiencies of 10-12% at 21.4 J and 6-7% at 5.35 J at cavity lengths between 14 mm and 29 mm.

• Journal of the Korean Institute of Rural Architecture
• /
• v.12 no.4
• /
• pp.13-20
• /
• 2010

This study takes notes on energy problems and sustainability of rural housing. The purpose of this study was to analyze the actual conditions of rural and applying energy saving of rural housing. For this, we tried to review literatures and conduct a field survey. The results of this study were as follows, first, rural housing of energy saving type environmental friendly applied planning factors with gradual carbon decrease by considering economic efficiency, current application and technical level. Second, the principal concepts of this housing are economic, locality and energy efficiency, it is applicable three kinds of the concepts of environmentally friendly housing. Third, this housing in planning must decrease energy consumption and increase air conditioning efficiency by means of air tightness and improvement insulation capacity.

• KIEAE Journal
• /
• v.12 no.6
• /
• pp.63-68
• /
• 2012

The aim of this study is to evaluate current policies and suggest the way of overcome financial impediments to the energy efficiency function of residential buildings. Based on this analysis the paper enumerates policy recommendations for enhancing how energy efficiency is addressed in building codes and other policies for residential buildings. For achieving this goal, this study conducts the cost-benefit analysis to measure total energy savings and associated total cost. The results of study shows that the cost is greater than the benefit from 1st to 4th year but the benefit will be greater than the cost for the rest of the year. In addition, this study designs a financial support method and an implementation mechanism. Investment from the capital market will take place with the government's interest subsidy. Home retrofit will be undertaken with low interest rate with 2.5% and the return will be paid by a monthly energy bill. The results of this study provides some useful insights for the policy design, including the importance of developing information tools for providing appropriate information to households.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.68 no.1
• /
• pp.19-26
• /
• 2019

As global demand for energy, energy prices, and power generation has increased worldwide, the government is turning to supply-oriented electricity supply and demand policies, such as behavior-based energy efficiency programs. In order to measure the implementation effect of the behavior-based energy efficiency program, the energy reduction must be accurately calculated by calculating the customer baseline load.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.18 no.3
• /
• pp.267-272
• /
• 2012

Carbon emission generated by energy issues is one of the major problems which all countries concern. The International Energy Agency recommends to improve 15-30[%] of energy efficiency than now. Government has pushed the domestic energy saving policies and incentives and penalties were also given in that direction. Pumps are widely used to transfer fluids and they consume at least 20[%] power of each nation. Their loss of energy is huge if they have been operated at low efficiency for long time. Low efficiency of these pumps is often due to incorrect design or degradation. Pump efficiency can be measured to estimate energy loss. If it is low, the pump may be repaired or replaced with new one. This paper introduces thermodynamic method to measure pump efficiency using only two kinds of sensors for temperature and pressure. It can calculate best efficiency point(BEP) of actual systems easily and fast. Its values were compared with the real performance curve provided by pump maker and we got almost similar performance curves from the repeated experiment.

• 한국태양에너지학회:학술대회논문집
• /
• 2009.11a
• /
• pp.211-215
• /
• 2009

As entering in the time of high oil price, seriousness of an energy is on the rise and the importance of energy is growing. Especially, building energy occupying 24% of total demand of energy is expected to be possible to reduce energy demand more than other section. To reduce the building energy consumption, this study analyzes function and thermal performance of Super window by heat experimental apparatus. Super window is a 2-track low-e glazing window for high insulation efficiency. By applying the results of this experiment to building energy efficiency rating tool, this study compares energy efficiency rates depending on a region.-Jeju, South, Central. And it shows how much does Super window reduce Building energy consumption.

• Journal of electromagnetic engineering and science
• /
• v.11 no.3
• /
• pp.161-165
• /
• 2011

In this paper, a high-efficiency DC-AC converter is used for wireless energy transmission. The DC-AC convertter is implemented by combining the oscillator and power amplifier. Given that the conversion efficiency of a DC-AC converter is strongly affected by the efficiency of the power amplifier, a high-efficiency power amplifier is implemented using a class-E amplifier structure. Also, because of the low output power of the oscillator connected to the input stage of the power amplifier, a high-gain two-stage power amplifier using a drive amplifier is used to realize a high-output power DC-AC converter. The high-efficiency DC-AC converter is realized by connecting the oscillator to the input stage of the high-gain high-efficiency two-stage class-E power amplifier. The output power and the conversion efficiency of the DC-AC converter are 40.83 dBm and 87.32 %, respectively, at an operation frequency of 13.56 MHz.