• 한국태양에너지학회:학술대회논문집
• /
• 2009.04a
• /
• pp.121-126
• /
• 2009

This study analyzed the standard school's energy usage and patterns as the zero-energy goal of primary school building, and proposed the energy reduction process of school building using energy analysis computing simulation tool. As a analysis simulation tool, Visual DOE 4.0 is used. For analysis of actual energy usage, selected primary school that is standard in the nation's energy consumption. Standard of the school's energy consumption analysis were devided into electric and gas energy. Input parameters of the simulation program based on the literature material and field survey material. after, but it was calibrated to comparison with the standard school's energy consumption. Finally, its energy usage analyzed by component and made the priority order of energy saving. Applied energy saving technologies are envelopment insulation, high efficiency lighting, high performance HAVC system and used active equipment system of solar collector and photovoltaic generation for additional savings.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.47 no.5
• /
• pp.98-103
• /
• 2015

The reduction of the energy consumption in papermaking process become more important issue because of the regulation of green house gas (GHG) emission. Since more than half of energy for papermaking process is consumed during drying process, the increase of the drying efficiency would be very important solution for saving energy and reduction of GHG emission. The improvement of drying efficiency could be very difficult for the liner board mill because the liner board are usually made of recycled paper, OCC (old corrugated container). The short fiber and fines originated the OCC lead to compact sheet structure and delay the water flow out during wet pressing process and drying process. The application of lignocellulose spacer could provide more loose wet sheet structure and result in the higher drainage rate and the improved drying efficiency. In this study, the effects of the application of lignocellulose spacer to the liner board mill were evaluated based on the mill trial. In order to overcome the common disadvantage of the spacer, the loss of strength properties, the spacer was pretreated with amphoteric polyelectrolyte during mill trial. The results showed the application of pretreated spacer improved the drying efficiency by reducing steam consumption. And the loss in the strength properties by the spacer could be supplemented by the pretreatment.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.25 no.5
• /
• pp.627-633
• /
• 2019

This study aimed to predict the resistance and propulsion performance of a ship using computational fluid dynamics (CFD) and a database as well as establish an assessment method for the energy efficiency design index (EEDI) using the results. First, the total resistance of the studied ship is obtained using CFD. A flow analysis is conducted with the free surface and trim and sinkage using a commercial CFD code (STAR-CCM+). The effective power of the ship is assessed based on the CFD results. The quasi-propulsive efficiency is calculated from an empirical prediction equation using experimental data and similar material. Finally, a general calculation program for the EEDI is established based on the hydrodynamic results, ship information for principal particulars, conversion factor of $CO_2$ for fuels, and fuel consumption.

• Environmental Engineering Research
• /
• v.24 no.3
• /
• pp.389-396
• /
• 2019

The electrical energy consumption (EEC) in removal of NO by a $UV/H_2O_2$ oxidation process was introduced and related to removal efficiency of this gas. The absorption-reaction of NO was conducted in a bubble column reactor in the presence of $SO_2$. The variation in NO removal efficiency was investigated for various process parameters including NO and $SO_2$ inlet concentrations, initial concentration of $H_2O_2$ solution and gas flow rate. EEC values were obtained in these different conditions. The removal efficiency was increased from about 22% to 54.7% when $H_2O_2$ concentration increased from 0.1 to 1.5 M, while EEC decreased by about 70%. However, further increase in $H_2O_2$ concentration, from 1.5 to 2, had no significant effect on NO absorption and EEC. An increase in NO inlet concentration, from 200 to 500 ppm, decreased its removal efficiency by about 10%. However, EEC increased from $2.9{\times}10^{-2}$ to $3.9{\times}10^{-2}kWh/m^3$. Results also revealed that the presence of $SO_2$ had negative effect on NO removal percentage and EEC values. Some experiments were conducted to investigate the effect of $H_2O_2$ solution pH. The changing of pH of oxidation-absorption medium in the ranges between 3 to 10, had positive and negative effects on removal efficiency depending on pH value.

• Transactions on Electrical and Electronic Materials
• /
• v.11 no.5
• /
• pp.206-211
• /
• 2010

Piezoelectric energy harvesting uses piezoelectric, which is able to convert unused mechanical vibration energy to electrical energy, such as with motor and machinery. The piezoelectric energy harvester was constructed with a cantilever made of lead zirconate titanate with a metal plate. The primary material was soft lead zirconium titanate (PZT-5H) due to the large strain availability, acceptable mechanical strength and high piezoelectric constant. This technique's drawback is that the energy efficiency is lower than the other energy harvesting methods, but this study increases the output electric power efficiency by analyzing a finite element method for the structure of the piezoelectric energy harvester. We manufactured two cantilever types as follows: the L-60 and L-33 bimorph piezoelectric energy harvesters. Their resulting energy harvesters were able to obtain high voltage values as follows: 27.4 mV and 40.6 mV. Moreover, these results have a similar band of resonance frequency it comparison to the simulation. Consequently, this study was confirmed with validity. The output electric powers of the L-60 and L-33 types have 3.1 mW/s and 5.8 mW/s with 47 Hz and 148 Hz of resonance frequency and then, the load resistivities were $100k\Omega$ and $10k\Omega$, respectively.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.7 no.11
• /
• pp.2676-2689
• /
• 2013

Due to increased consumption of energy in the building environment, the building energy management systems (BEMS) solution has been developed to achieve energy saving and efficiency. However, because of the shortage of building energy management specialists and incompatibility among the energy management systems of different vendors, the BEMS solution can only be applied to limited buildings individually. To solve these problems, we propose a building cluster based remote energy monitoring and management (EMM) system and its functionalities and roles of each sub-system to simultaneously manage the energy problems of several buildings. We also introduce a novel energy demand forecasting algorithm by using past energy consumption data. Extensive performance evaluation study shows that the proposed regression based energy demand forecasting model is well fitted to the actual energy consumption model, and it also outperforms the artificial neural network (ANN) based forecasting model.

• 제어로봇시스템학회:학술대회논문집
• /
• 2003.10a
• /
• pp.2304-2308
• /
• 2003

Ocean thermal energy conversion (OTEC) is an effective method of power generation, which has a small impact on the environment and can be utilized semi-permanently. This paper describes a dynamic model for a pilot OTEC plant built by the Institute of Ocean Energy, Saga University, Japan. This plant is based on Uehara cycle, in which binary mixtures of ammonia and water is used as the working fluid. Some simulation results attained by this model and the analysis of the results are presented. The developed computer simulation can be used to actual practice effectively, such as stable control in a steady operation, optimal determination of the plant specifications for a higher thermal efficiency and evaluation of the economic prospects and off-line training for the operators of OTEC plant.

• Proceedings of the SAREK Conference
• /
• 2009.06a
• /
• pp.114-119
• /
• 2009

This study has been conducted to describe the establishment of national measures to reduce world energy consumption and $CO_2$ Emission. Particularly, Reductions in energy consumption from building operation is the most important part to achieve these national objectives. Element to evaluate the quantitative effects of these systems by having rationalized regulation and operation is essential, when planning for building energy reduction design. USGBC(US Green Building Council) have operated sustainable assessment method called LEED, which introduces baseline performance and evaluation direction for building simulation techniques. This research analyzed Quantitative assessments of the building energy consumption and analyzed baseline figures to provide comparative analysis with standard building settings.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2012.05a
• /
• pp.265-266
• /
• 2012

Recently, preparing countermeasures about energy depletion and CO₂ emission progressing rapidly is considered as an urgent problem not only in domestic country but also in international countries. Among this, the requirement for the comfort development of in door environment is increasing according to housing culture and life environment changing. Thus, it is required urgently to save building energy and develop fusion technology maintaining comfort of indoor environment. Recently, energy-saving ways in saving heating and cooling energy by latent heat and thermal storage is considered significantly. In this study, keeping up with the times, thermal performance analyzed. Also, this study has the aim to draw materials for evaluating usefulness and efficiency.

• Journal of the Korean Society for Precision Engineering
• /
• v.30 no.9
• /
• pp.977-982
• /
• 2013

Blades of wind energy plants are exposed to external shocks or internal cracks during operation. Furthermore, the blade surfaces can be contaminated by substances such as dust, blood of birds, salt or insects which can decrease the electricity generation efficiency significantly. For this reason, many blade cleaning companies started to appear and a variety of methods for cleaning were suggested. Despite these diverse methods, there has been no study to investigate how effectively to clean the substances in quantitative manner. In this paper, the cleaning efficiency of two rotor blade cleaning methods, brush and water-jet, is examined through experiments by changing operating parameters. Then, the optimal operating conditions for both methods are derived.