• 한국태양에너지학회:학술대회논문집
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• 2009.04a
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• pp.91-96
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• 2009

First, the base model of multi-family residential buildings are selected, and then the $CO_2$ reduction building technologies that are applicable for multi-family residential buildings are induced by analyzing the examples and then an optimal plan for when the $CO_2$ reduction building technologies can be integrated and applied to the base model was formulated. In the results of converting the energy consumption and reduction amount from the building technologies into $CO_2$ emissions to analyze the distribution ratio compared to the entire $CO_2$ emissions; the heat recovery ventilator is 0.5%, the photovoltaic system is $1.9%{\sim}5.9%$, the solar hot water heating system is $6.3%{\sim}13.1%$ and the ge thermal heat-pump system is 39.0% when both heating and hot water heating are applied. An optimally integrated application method for the building technologies is in charge of heating and hot water heating through the geothermal source heat pump system and in charge of the electricity load through the photovoltaic system(45.2%).

• Plant Journal
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• v.14 no.4
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• pp.39-47
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• 2018

In this research, when the output of the standard coal-fired thermal power plant operating continuously at the rated output of 500 MW is changed to operate at 300 to 500 MW, the amount of sulfur oxide produced and the amount of sulfur oxide in the absorption tower of desulfurization equipment and proposed an extra liquid to gas ratio improvement inversely proportional to the output. In order to calibrate the combustion efficiency at low power, the ratio of sulfur oxides relative to the amount of combustion gas is increased as the excess air ratio is increased. When the concentration of sulfur oxide at the inlet of the desulfurization absorber was changed from 300 to 500 ppm along with the output fluctuation. The liquid to gas ratio of limestone slurry and combustion gas was changed from 10.99 to 16.27. Therefore, if the concentration of sulfur oxides with output of 300 MW is x, The following correlation equation is recommended for the minimum required flow rate of slurry for the reduction of surplus energy due to the increase of the liquid weight at low load. $y1[m^3/sec]=0.11x+3.74$

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2192-2197
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• 2008

An experimental study was performed to investigate the effects of configuration of burner and air excess ratio on CO & NOx emission characteristics of the cooktop burners which are used extensively. In this study, the combustion characteristics were investigated with the variation of design factor of cooktop burners. The results showed that as the thermal input increases, flammable region go narrower. With the increase of loading height from the cap to grate, the CO emission decrease owing to the reduction of quenching by flame impingement on the load. Additionally, the CO emission increase with angle of main slot, however the NO emission is almost unaffected.

• Steel and Composite Structures
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• v.43 no.5
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• pp.673-688
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• 2022

Post-earthquake fire is a major threat since most structures are designed allowing some damage during strong earthquakes, which will expose a more vulnerable structure to post-earthquake fire compared to an intact structure. A series of experimental research on steel-concrete composite beam-to-column joints subjected to fire after cyclic loading has been carried out and a clear reduction of fire resistance due to the partial damage caused by cyclic loading was observed. In this paper, by using ABAQUS a robust finite element model is developed for exploring the performance of steel-concrete composite joints in post-earthquake fire scenarios. After validation of these models with the previously conducted experimental results, a comprehensive numerical analysis is performed, allowing influential parameters affecting the post-earthquake fire behavior of the steel-concrete composite joints to be identified. Specifically, the level of pre-damage induced by cyclic loading is regraded to deteriorate mechanical and thermal properties of concrete, material properties of steel, and thickness of the fire protection layer. It is found that the ultimate temperature of the joint is affected by the load ratio while fire-resistant duration is relevant to the heating rate, both of which change due to the damage induced by the cyclic loading.

• Journal of Korea Foundry Society
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• v.25 no.6
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• pp.259-264
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• 2005

The copper clad steel wire is used extensively as lead wires of electronic components such as capacitors, diodes and glass sealing lamp because the wire combines the strength and low thermal expansion characteristic of Fe-Ni steel with the conductivity and corrosion resistance of copper. In order to fabricate the copper clad steel wire, several processes including electro-plating, tubecladding extrusion process and dip forming process have been introduced and applied. The electroplating process for the production of copper clad steel wire shows poor productivity and induces environmental load generation such as electroplating solution. The dip forming process is suitable to mass production of copper clad steel such as trolley wire. and need expensive manufacturing facilities. The present paper describes the improvement of the conventional continuous casting process to fabricate copper clad steel wire, which its core metal is low thermal expansion Fe-Ni alloy and its sheath material is copper. In particular, the formation of intermetallic compound at interface between core and sheath was investigated in order to introduce optimum continuous casting process parameter for fabrication of copper clad steel wire with higher electrical conductivity. The mechanical strength of copper clad steel wire was also investigated through wiredrawing process with of 95% in total reduction ratio.

• Journal of the Korea Institute of Building Construction
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• v.18 no.1
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• pp.9-15
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• 2018

Radon gas, which is present on the earth, is a primary carcinogen released from rocks, soil, building materials, etc., and exists as a unique gas phase. In order to solve the risk of radon gas, we evaluated the basic performance which can be used as indoor finishing materials in addition to the radon gas reduction properties of the matrix using anthracite. An anthracite used as a conventional filter material was used to produce a matrix, and a test was conducted to replace the gypsum board, which is one of the building materials used in the existing room. As the anthracite replacement ratio increases, flexural failure load strength increases and thermal conductivity tends to decrease. Depending on the thickness of the board, the reduction performance of radon gas shows a slight difference.

• Journal of the Korea Institute of Building Construction
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• v.19 no.2
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• pp.139-147
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• 2019

In this study, an experiment was conducted to evaluate the properties of cement matrix using diatomite and silica gel as adsorbents of radon. The adsorption properties of diatomite of a natural adsorbent and silica gel of an artificial sorbent were examined to confirm the reduction of radon gas concentration of the removal of radon gas in the indoor environment of the human body. We conducted a performance evaluation for the study. The fluidity, air content, density, absorption, flexural failure load, thermal conductivity and radon gas concentration of the specimen using diatomite and silica gel were measured. the fluidity and the air content of the adsorbed matrix with diatomite were decreased as the diatomite replacement ratio increased. Which seems to affect the subsequent matrix by the absorption of the compounding water of diatomite. As the replacement rate of silica gel increased, the fluidity decreased and the air content increased up to constant replacement rate. It is judged that the surface of the silica gel has a critical point at which it can react with moisture.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.384-390
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• 2019

The importance of architecture design focused on eco-friendly and low energy continues to grow. In addition, the energy conservation design is required from a micro-perspective. Energy simulations based on BIM have attracted recent attention because of the high efficiency. On the other hand, the parameters concerned with microscopic energy are not included in BIM data. This study examined the necessity of the sensor-light parameter using a simulation of illuminance sensor light. In this study, illuminance sensors were installed into the BIM data and the operating schedule data of sensor light were generated by an illuminance simulation. The schedule data was then inputted into the simulation application, and the reduction ratio of power consumption was verified by the simulation. According to research, the power consumption and thermal load decreased by more than 20 %. Therefore, it is necessary to supplement the sensor-light parameter into BIM data for microscopic energy conservation design. This study was not confined to checking whether sensor-light parameter is necessary or not, but to ascertaining the necessary of applying a microscopic factor to generate BIM data.

• Journal of the Korean Institute of Gas
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• v.26 no.3
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• pp.45-53
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• 2022

In order to improve the emission of diesel engines, natural gas-diesel dual fuel combustion compression ignition engines are in the spotlight. In particular, a reactivity controlled compression ignition (RCCI) combustion strategy is investigated comprehensively due to its possibility to improve both efficiency and emissions. With advanced diesel direct injection timing earlier than TDC, it achieves spontaneous reaction with overall lean mixture from a homogeneous mixture in the entire cylinder area, reducing nitrogen oxides (NOx) and particulate matter (PM) and improving braking heat efficiency at the same time. However, there is a disadvantage in that the amount of incomplete combustion increases in a low load region with a relatively small amount of fuel-air. To solve this, sensitive control according to the diesel injection timing and fuel ratio is required. In this study, experiments were conducted to improve efficiency and exhaust emissions of the natural gas-diesel dual fuel engine at low load, and evaluate combustion stability according to the diesel injection timing at the operation point for power generation. A 6 L-class commercial diesel engine was used for the experiment which was conducted under a 50% load range (~50 kW) at 1,800 rpm. Two injectors with different spray patterns were applied to the experiment, and the fraction of natural gas and diesel injection timing were selected as main parameters. Based on the experimental results, it was confirmed that the brake thermal efficiency increased by up to 1.3%p in the modified injector with the narrow-angle injection added. In addition, the spray pattern of the modified injector was suitable for premixed combustion, increasing operable range in consideration of combustion instability, torque reduction, and emissions level under Tier-V level (0.4 g/kWh for NOx).