• Membrane and Water Treatment
• /
• v.14 no.2
• /
• pp.55-63
• /
• 2023

In this study, the influence of different IEMs (ion exchange membranes) to performance of the hypochlorite electrolysis unit with Cl₂ recovery stream was investigated. More specifically, Nafion 117-a representative cation exchange membrane (CEM)-and aminated polypheylene oxide (APPO)-an anion exchange membrane (AEM)-were installed in the hypochlorite electrolysis unit, and the performance and the energy efficiency of the units were evaluated and compared. Regardless of whether CEM (Nafion 117) or AEM (APPO) was installed, the rate of hypochlorite generation was increased (by up to 24.3% and 22.2% for Nafion 117 and APPO, respectively) compared with the unit without an IEM. On the other hand, the power efficiency and the optimum operation condition of hypochlorite production units seem to depend on the conductivity and stability of the installed IEM. As the result, between Nafion 117 and APPO, higher performance and efficiency were achieved with Nafion 117, due to excellent conductivity and stability of the membrane.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.19 no.12
• /
• pp.811-820
• /
• 2007

A Study on the optimal design of the AIG(Ammonia Injection Grid) to improve the performance of DeNOx facilities in the HRSG(Heat Recovery Steam Generator) was performed using the CFD analysis. On the basis of the flow analysis results in the case that the AIG in the HRSG was not installed, the numerical analyses according to the positions of AIG, injection angles of nozzle and the control of ammonia injection quantity were carried out. The standard deviation according to factors was calculated for quantitative comparison. As the results, the AIG in the HRSG should be installed in the position that the uniform flow field shows through the exact flow analysis in the previous of the AIG design and installation. In the case the AIG has already been installed and non uniform flow distribution shows, it is recommended that flow correction device or KoNOx catalyst should be used. Otherwise, the control of ammonia injection angle or the ammonia injection quantity using the velocity profile analysis is demanded to accomplish the optimal performance.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.60 no.6
• /
• pp.73-81
• /
• 2018

In this study, subsurface discharge performance has been studied through theoretical seepage analysis on four types of culverts that can be installed under the condition of non-excavation, such as (a)perforated pipe(${\Phi}50mm$), (b)perforated pipe+horizontal mat (B50cm) (c)perforated pipe+horizontal mat+vertical gravel(B<10cm), (d)perforated pipe+vertical gravel(B<10cm), and existing typical type (e)perforated pipe with gravel (B40, h=40cm) which can be installed by excavation. The analysis results were as follows. i) Subsurface discharge performance per unit (m) was (a)type 56%, (b) 91%, (c) 96%, (d) 76%, respectively, lower than the value of (e)culvert. ii) However, considering that non-excavation culvert can be installed at a spacing of 5m with the installation cost of the existing excavation culvert at the interval of 10m, it was analyzed that unit subsurface discharge(q) of (a)20.2mm/day(110%), (b)32.8(178%), (c)34.6(188%) (d)27.5(149%) in the four types of non-excavation culvert installed at intervals of 5m under the condition of $ k=10^{-4}cm/s$ was much larger than the amount of (e)type 18.5(100%), existing excavation culvert installed at 10m interval. iii) Through the test construction, peak subsurface drainage discharge($q_p$) was 38.4mm/day, which is larger than the value of design criteria and confirmed that it satisfies the analysis results as well. iv) In particular, it was evaluated that (b)perforated pipe+horizontal mat(B50cm) are low cost, high efficiency subsurface drainage culvert type with sufficient drainage performance(178%).

• KIEAE Journal
• /
• v.16 no.6
• /
• pp.123-128
• /
• 2016

Purpose: In order to save the energy consumption of buildings, buildings have been constructed with high performance insulation or airtightness. However, high performance insulation or air tightness has led to a poor indoor air quality. Therefore, HRV(Heat Recovery Ventilator) has received attention to save the energy consumption and insure a good air quality. Because existing research is almost about the performance of HRV in residential buildings, This study analyzed the effect of HRV on cooling energy consumption in commercial office building. Method: This study was proceeded at commercial office building in In-cheon. In order to evaluate the energy consumption of HRV, this study proposed two methods: estimating energy consumption of the room installed AHU(Air Handling Unit) system; estimating energy consumption of the room installed HRV system. Therefore, comparison of two methods was proceeded to evaluate energy performance of each method. Result: As the result of comparison between rooms installed AHU and HRV, the experiment showed that energy consumption of the room installed HRV system is about 22% less than the room of AHU system. This conclusion is considered because the room installed HRV system have maintained temperature well at set point temperature $26^{\circ}C$.

• Journal of the Korea Safety Management & Science
• /
• v.18 no.2
• /
• pp.83-92
• /
• 2016

Because National Fire Safety Codes is mixed performance criteria and specification, and it defines the fire extinguish equipment type and standards that need to be installed in a building as one method. Therefore, to fully reflect the fire risk characteristics of the building, such as the wooden building there is a limit. In this study, suggested to the performance criteria drawn methodologies through fire load of wooden buildings studies, theory on performance and performance analysis to fire extinguish equipment of the wooden buildings is installed according to current fire safety codes.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.43 no.6
• /
• pp.709-719
• /
• 2023

In general, most of the electrical equipment responsible for control within power plants is housed in self-standing cabinets. These cabinets are typically fixed to a slab using post-installed anchors. Although the fixation method of using post-installed anchors provides stability, there is a risk of conductor failure due to external forces, including moments. However, the performance assessment of current anchors is only evaluated through uniaxial material tests. Therefore, the primary purpose of this study is to compare the static performance of post-installed anchors, considering on-site installation conditions, with their performance in material tests and to analyze the behavioral characteristics of the anchors. While conducting experiments using actual cabinets would be ideal, practical and spatial constraints make this approach difficult. As an alternative, experiments were conducted using a test specimen consisting of a steel column and a support. As a result, the pull-out performance of anchors reflecting on-site installation conditions was measured to be about 10% higher than that observed in material tests. The trends in load reduction and the point of maximum performance for the anchors also differed. To verify the reliability of the experimental study, a 3D FEM analysis was performed, which will provide predictive information on the loads transferred to the post-installed anchors for structural performance evaluations of electrical cabinets using shaking table test in the future.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.25 no.3
• /
• pp.150-155
• /
• 2013

Usually, a window tends to have a lower thermal performance, than that of an ordinary wall. This study analyzes the enhancement of thermal performance of a window, when a Thermal Insulation Shutter is installed. The analyses were conducted at the laboratory, and with a full-scale mockup house, and the U-factor and heating load were examined. The laboratory results show that the U-factor increased by approximately 28%, when a Thermal Insulation Shutter was installed. The temperature difference was about $5^{\circ}C$, and this shows that the Thermal Insulation Shutter enhances the thermal performance of the window, when installed. The mockup house was used to calculate the heating load; the heating load was reduced by more than 41%, and shows that the installation of a Thermal Insulation Shutter is an effective way to reduce heating energy consumption.

• Nuclear Engineering and Technology
• /
• v.53 no.8
• /
• pp.2499-2508
• /
• 2021

Passive containment cooling systems (PCCSs) have been actively studied to improve the inherent safety of nuclear power plants. Hered, we present two concepts, open-loop PCCS (OL-PCCS) and closed-loop PCCS (CL-PCCS), applicable to the PWR with a concrete-type containment. We analyzed the heat-removal performance and flow instability of these PCCS concepts using the GOTHIC code. In both cases, PCCS performance improved when a passive containment cooling heat exchanger (PCCX) was installed in the lower part of the containment building. The OL-PCCS was found to be superior in terms of heat-removal performance. However, in terms of flow instability, the OL-PCCS was more vulnerable than the CL-PCCS. In particular, the possibility of flow instability was higher when the PCCX was installed in the upper part of the containment. Therefore, the installation location of the OL-PCCS should be restricted to minimize flow instability. Conversely, a CL-PCCS can be installed without any positional restriction by adjusting the initial system pressure within the loop, which eliminates flow instability. These results could be used as base data for the thermo-hydraulic evaluation of PCCS in PWR with a large dry concrete-type containment.

• Journal of the Korean Solar Energy Society
• /
• v.38 no.4
• /
• pp.11-31
• /
• 2018

Nowadays, domestic photovoltaic system market has been expanded and the governmental dissemination policy has been continued. There is only PV system output performance analysis which is called Performance Ratio(PR) analysis. However, there exists many parameters that can affect PV system output. This papers shows the PV system energy performance analysis using meteorological monitoring data. The meteorological monitoring system was installed in the H university and we analyzed the PV system which installed in the H university. We also investigated other three PV systems which located less than 3 kilometers from H university. We evaluated total 4 PV systems through the field survey data, design drawing data and power generation data. Finally, we compared the actual measuring data with the simulation data using PVSYST software.

• Journal of the Optical Society of Korea
• /
• v.10 no.3
• /
• pp.112-117
• /
• 2006

We experimentally investigated the transmission characteristics of 400 Gbit/s (10 Gbit/s ${\times}$ 40 channels) WDM signals with 100 GHz channel spacing over 323 km of installed NZ_DSF. The installed fiber has optical properties of 0.28 dB/km attenuation, 4.3 ps/nm/km dispersion, $0.083ps/nm^2/km$ dispersion slope and less than $0.05ps/km^{1/2}$ PMD coefficient. In this experiment, two cases of dispersion compensation schemes, the lumped type and the distributed type, were compared. The results implied that the distributed type dispersion compensation in which dispersion compensation devices are inserted at the end of the each span showed better transmission performance than the lumped one in which dispersion compensation devices are located at the transmitter and receiver sites. From the analysis of the experimental results, we verified that different transmission performance comes from the power penalty induced by XPM in the distributed scheme is lower than the lumped scheme case.