• Korean Journal of Metals and Materials
• /
• v.48 no.4
• /
• pp.277-288
• /
• 2010

The hot corrosion properties of heat-resistant steels were investigated in an oxidation atmosphere including artificial ash and sulfur dioxide. The heat-resistant steels of T22, T92, T122, T347HFG, Super304H and HR3C were evaluated at 620, 670 and $720^{\circ}C$ for 400 hours. The relationship between the corrosion rate and the temperature followed a bell-shaped curve with a peak rate at around $670^{\circ}C$. The corrosion rates showed a decreasing tendency as the chrome contents of these steels increased from 2.15 wt.% to 24.5 wt.%, and austenitic steels had a lower corrosion rate than ferritic steels. Sulfidation by $SO_2$ as well as molten salt corrosion also had an effect on the total corrosion rate, especially showing an increase in the corrosion rate in ferritic steels. Regardless of the chrome content in the steels and irrespective of the test temperature, the corrosion scale was composed of an outer oxide and an artificial ash mixed layer, a middle oxide layer and inner sulfide, and a mixed oxide layer. As the chrome content increased, the proportion of chrome oxide in the corrosion scale increased. Before spalling of the corrosion scale, voids and cracks were initiated in the sulfide and the mixed oxide layer or at the interface with the substrate.

• Transactions of the Korean hydrogen and new energy society
• /
• v.33 no.4
• /
• pp.419-429
• /
• 2022

Effects of operating variables on temperature profile and performance of 3 MWth chemical looping combustion system were estimated by mass and energy balance analysis based on configuration and dimension of the system determined by design tool. Air reactor gas velocity, fuel reactor gas velocity, solid circulation rate, and solid input percentage to fluidized bed heat exchanger were considered as representative operating variables. Overall heat output and oxygen concentration in the exhaust gas from the air reactor increased but temperature difference decreased as air reactor gas velocity increased. Overall heat output, required solid circulation rate, and temperature difference increased as fuel reactor gas velocity increased. However, overall heat output and temperature difference decreased as solid circulation rate increased. Temperature difference decreased as solid circulation rate through the fluidized bed heat exchanger increased. Effect of each variables on temperature profile and performance can be determined and these results will be helpful to determine operating range of each variable.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.30 no.2A
• /
• pp.161-168
• /
• 2010

The bonded tendon was adopted to the reactor building of some operating nuclear power plants in Korea and the assessment of the effective prestress force on the bonded tendon is being issued as an important pending problem for continuous operation beyond their design life. The sensitivity analysis of various parameters was carried out to evaluate the effective prestress force using the system identification technique and the optimal parameters were determined for SI technique in this study. The 1/5 scaled post-tensioned concrete beams with the bonded tendon type were manufactured and in order to investigate the relationship of the natural frequency and the displacement to the effective prestress force, impact test, SIMO sine sweep test and bending test using the optical fiber sensor and the compact displacement transducer were carried out. As a result of tests, both the natural frequency and the displacement show the good relationship with the effective prestress force and both parameters are available for the SI technique to estimate the effective prestress force.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
• /
• v.40 no.6
• /
• pp.40-47
• /
• 2011

지중축냉시스템, 흡수식히트펌프, 천장형복사패널+바닥급기 공조방식 등의 획기적 에너지절약 시스템을 반영한 한국전력공사 신사옥건립 기계분야 기본설계 사례를 소개하고자 한다.

• 열병합발전
• /
• s.59
• /
• pp.9-13
• /
• 2007

한국전력 해외사업본부에서 나이지리아 엑빈발전소 O&M(Operation and Maintenance) 및 보일러 복구공사를 추진하고 있으며, 보일러 복구공사는 현재 수행이 되고 있다. 이와 관련하여 전력연구원에서는 엑빈발전소에서 발생한 보일러 폭발 발생원인과 대책을 수립하기 위하여 현장 진단을 수행하였다. 따라서 보일러 폭발에 대한 발생 Mechanism과 대책을 소개함으로서 보일러 유지관리에 참고가 되고, 보일러 폭발과 같은 대형사고를 방지하는데 도움이 되기를 바란다.

• Electric Engineers Magazine
• /
• v.173 no.1
• /
• pp.28-38
• /
• 1997

전력기술관리법에서 전력시설물에 대한 설계 및 감리제도를 신설하고 전력기술인 및 감리원의 경력 관리제도를 마련하여 부실공사를 미연에 방지하고 전력기술인의 권익신장 및 편의를 도모할 수 있도록 하였습니다. 전력기술인이란 감리원의 등급 또는 경력의 확인을 받고나 하는 전력기술인 및 감리원을 고용하고 있는 관리주체 또는 사용자는 소속된 전력기술인 및 감리원의 현황을 한국전력기술인협회에 제출하여야 합니다.

• NEWSLETTER 전기공업
• /
• no.94-11 s.108
• /
• pp.32-39
• /
• 1994

• JOURNAL OF ELECTRICAL WORLD
• /
• no.9 s.141
• /
• pp.39-47
• /
• 1988

• Journal of Radiation Industry
• /
• v.2 no.3
• /
• pp.141-148
• /
• 2008

Beta rays emitted from tritium in titanium tritide film were simulated with cathode rays of a scanning electron microscope to investigate the effect of beta rays from tritium on semiconductor devices. The cathode ray currents, which vary with the change of applied energy and beam spot size, were measured with Faraday cup. The current from the semiconductor device irradiated with cathode rays at various conditions was measured. The cathode ray current increased with the increase of spot size to a maximum then decreased when the spot sized increased further. The magnitude of current produced in the semiconductor device is proportional to the magnitude of cathode ray current. The magnitude of cathode ray current at each energy level was matched to the intensity of beta ray to simulate the tritium beta ray spectrum. Then the semiconductor characteristics were analyzed with I-V curves.

• Journal of the Korean Society of Mechanical Technology
• /
• v.13 no.3
• /
• pp.81-85
• /
• 2011

The night time electric cost is cheaper due to electric supply and demand policy in Korea from 1985. Currently about 900,000 customers are using night time electric heating boilers and this causes shift of peak demand time to night in winter and increase of deficit spending. To solve this problem, replacing night time electric heating boiler by air-source heat pump using night time electricity has been proposed. An air-source heat pump can provide efficient heating equipment especially in a warm climate. For estimating the night time electric heat pump COP(Coefficient of Performance), Korean Standard KS C 9306:2010 and European Standard EN-14511:2004 is available. SCOP(Seasonal COP) using European weather bin data is also calculated. SCOP is not available yet but European Committee for Standardization will establish a standard in the near future. The evaluation result show that the replacing night time electric heating boiler by heat pump can be possible.