• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2012.10a
• /
• pp.304-306
• /
• 2012

In this Paper, we develop control system for disinfection of welfare Equipment. In this paper, the developed system including disinfection control circuit using Hydrogen peroxide steam, chamber control circuit for disinfection using low vacuum and washing system control circuit using micro bubble.

• Proceedings of the Korean Society of Agricultural Engineers Conference
• /
• 1999.10c
• /
• pp.465-472
• /
• 1999

Hydraulic model tests are performed to find economical and hdrqulically stable design of cooling water intake channel of steam power plant. The result of tests show that the standard distributiion of y-components in the chamber of CWP(circulating Water Pump) are recommended below 3.5 to maintain hydraulic stability, so that this value is considered as the design criteria. Common basin is necessary to improve the hydraulic stability of inflow, however the longer basin does not always improve the hydraulic stability , and the optimal length of basin can be found in some range. From the results the flow stability maintained the best condition when the length of basin is 7.2m. Beside the standard tests the auxiliary tests like edge , baffle, trapezoidal section and increase of pump capacity are carried out based on the optimal condition foudn in the standard tests. From the series of tests the economical and hydraulically stable design of intake channel was proposed.

• Applied Chemistry for Engineering
• /
• v.28 no.4
• /
• pp.467-472
• /
• 2017

In this study, the reforming reaction of vacuum residue (VR) was carried out using aquathermolysis reaction. VR showed a prone to decrease the amount of resins and asphaltenes in the constituents, and to increase saturates and aromatics when reacting with steam at 30 bar and above $300^{\circ}C$ for 24 h. This tendency became more evident when the amount of steam used was excessive than the amount of VR. When the aquathermolysis reaction was performed at $300^{\circ}C$ and 30 bar for 48 h, the VR composition was changed from the initial state (S/A/R/A = 7.3%/43.7%/25.6%/23.5%) to final state (S/A/R/A = 6.8%/57%/12.2%/24.0%), and the contents of the resins decreased by 13% and the aromatic compounds increased by 13%. The viscosity decreased from 880,000 cp to 290,000 cp by 68%. When 10% of decalin, which is easy to provide hydrogen, was added, the viscosity decreased by 68% in 24 h. The VR composition showed a reduction in the contents of resins and asphaltenes from 49% to 17% from the initial state (S/A/R/A = 7.3%/43.7%/25.6%/23.5%) to the final state (S/A/R/A = 4.5%/63.5%/12.5%/20.0%), and the content of aromatics was maximized to 63.5%. The gas layer formed by the aquathermolysis reaction in the reactor chamber was collected and analyzed by GC-MS spectroscopy. As a result, various hydrocarbon compounds such as ethylbenzene, octane and dimethylbenzene were detected.

• Applied Chemistry for Engineering
• /
• v.25 no.3
• /
• pp.262-267
• /
• 2014

SAGD (steam assisted gravity drainage) process is the most commonly used in-situ technology for the recovery of bitumen from oil sand. It was investigated that the effects of different additives on bitumen recovery rate from oil sand in SAGD process among many possible mechanisms studied throughout the study. Bitumen recovery from thin layer oil sand reservoirs was simulated by using an experimental SAGD apparatus with scale of 150:1. To improve the simulation accuracy of thin layer oil reservoir, we have attached geological model (GM). Oil sand was simulated by using a mixture of extra heavy oil and glass beads with a diameter of 1.5 mm. $CO_2$ was used as an additive and the evolution of steam chambers were closely monitored, and the effects of $CO_2$ as an additive was investigated. Two types of injection methods were tested; continuous ($cCO_2$-SAGD) and sequential interruption ($sCO_2$-SAGD) $CO_2$ injection. For the $sCO_2$-SAGD experiment, it was observed that the recovery rates and CSOR were efficiently improved control experiment from 60.2% to 69.3% and 7.1 to 6.0, respectively, whereas $cCO_2$-SAGD experiment decreased from 60.2% to 57.6% and 7.1 to 7.3.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.16 no.5
• /
• pp.965-973
• /
• 1992

Boilers, which are considered to be one of the basic equipment in industry, consume large potion of nation's petroleum and their demand is growing everyday. In recent, the technology improvement in production of high efficiency boilers and their effective utilization is needed for design of boiler which steam condition is the large capacity of high temperature and high pressure. It is necessary that boiler control system be studied for high efficiency, high reliability and smooth operation. The control of drum pressure and water level particularly becomes an important task for greater accuracy with the avail ability of boiler operation. To achieve this aim, dynamic analysis of a boiler is accomplished by choosing a boiler as a model. Transfer function thus obtained is made a comparison of measurement with reckoning to technical design data. The results of comparison makes it possible to verify thermodynamical analysis on the dynamic behavior of the overall system.

• Journal of the Ergonomics Society of Korea
• /
• v.36 no.5
• /
• pp.559-568
• /
• 2017

Objective: The aim of this study is to investigate the effective managerial factors influencing dose reduction of the nozzle dam installation and removal tasks ranking within top 3 in viewpoint of average collective dose of nuclear power plant maintenance job. Background: International Commission on Radiation Protection (ICRP) recommended to reduce unnecessary dose and to minimize the necessary dose on the participants of maintenance job in radiation fields. Method: Seven sessions of nozzle dam installation and removal task logs yielded a multiple regression model with collective dose as a dependent variable and work time, number of participants, space doses before and after shield as independent variables. From the sessions in which a significant reduction in collective dose occurred, the effective managerial factors were elicited. Results: Work time was the most important factor contributing to collective dose reduction of nozzle dam installation and removal task. Introduction of new technology in nozzle dam design or maintenance job is the most important factor for work time reduction. Conclusion: With extended task logs and big data processing technique, the more accurate prediction model illustrating the relationship between collective dose reduction and effective managerial factors would be developed. Application: The effective managerial factors will be useful to reduce collective dose of decommissioning tasks as well as regular preventive maintenance tasks for a nuclear power plant.

• Journal of the Korean Institute of Gas
• /
• v.5 no.4 s.16
• /
• pp.27-32
• /
• 2001

It is desired that carbon dioxide causing a greenhouse effect be removed at a high temperature and high pressure in a steam reforming reaction. In this research, a pellet form of adsorbent CaO is employed to capture $CO_2$. The adsorbent was manufactured using a high pressure molding on powdered $CaCO_3$ followed by calcination. Then its properties were analyzed and the adsorption experiments were carried out in a batch adsorption chamber. The pore area was found to be dependent on a molding pressure and the pore distribution showed two peaks. It is examined that $CO_2$ binds to CaO by means of chemisorption and its maximum conversion is nearly $80\%$ at $700^{\circ}C$.

• Environmental Engineering Research
• /
• v.20 no.2
• /
• pp.171-174
• /
• 2015

This study investigates the possibility of applying food waste leachate to a municipal solid waste incinerator in order to effectively dispose of the material and to reduce the environmental impact. The spray positions and the quantity of the food waste leachate in municipal solid waste incinerator were adjusted to examine the stability of the process and the environmental effect. The rear of the first combustion chamber was found to be the desirable location for an environmental perspective in this study. At a food waste leachate injection rate of $2m^3/h$, the concentration of the emitted NOx decreased from 130 ppm to 40 ppm. The consumption of ammonia water was reduced by about 36% after adding the food waste leachate. The inclusion of the food waste leachate to the municipal incinerator also increased the amount of steam that was produced. The results of this research indicated that a positive outcome can be expected in terms of diversifying the treatment options for food waste leachate. The results also provide guidance for institutional framework to manage the incineration of the food waste leachate.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.6 no.3_4
• /
• pp.97-100
• /
• 1973

In the previous work(Kim et al, 1973), the quality of sun-dried Alaska pollack, Theragra chalch-ogramma, was discussed in the aspect of non-enzymatic discoloration as a function of relative humidity during storage at room temperature($20^{\circ}C$). In this paper, sun-dried squid, Ommastrephes steam pacificus was investigated at the same aspect mentioned above. Fresh squid from the whole sale market was dressed, filleted, dried for 48 hours in the open air and finally stored in the humidistat chamber. Lipid oxidation ana development of non-enzymatic browning were tested by the same methods described in the previous paper. The TBA value showed a maximum peak on 30 day storage, hereafter tended to decrease gradually. The rate of browning, however, in water soluble fraction as well as in chloroform-methanol fraction was lower at 0.34 to 0.45 water activity than at any other case, and propagation of lipid oxidation was also diminished at the above level of water activity. From the results, it is recognized that storage at Aw=0.34 to 0.45 provides higher quality stability for sun-dried squid.

• Journal of Radiation Protection and Research
• /
• v.35 no.2
• /
• pp.57-62
• /
• 2010

Maintenance on the water chamber of steam generator, the change of pressurizer heater, the removal of pressure tube feeder, and so on during outage in nuclear power plants (NPPs) has a likelihood of high radiation exposure to whole body of workers even short time period due to the high radiation exposure rates. In particular, it is expected that hands would receive the highest radiation exposure because of its contact with radiation materials. In this study, field tests on extremity dose assessment of radiation workers for contact works with high radiation exposure were conducted during the maintenance periods in Korean pressurized water reactors (PWRs) and pressurized heavy water reactors (PHWRs). In this field test, radiation workers were required to wear additional TLDs on the back and wrist, and an extremity dosimeter on fingers including a main TLD on the chest, while performing maintenance. As a result, it was found that the equivalent dose for fingers was distributed in the fixed range of deep dose and the equivalent dose for wrists.