• 한국산업융합학회 논문집
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• 제25권6_3호
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• pp.1199-1206
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• 2022

Fossil fuels are one of the various energy sources used by humans, and industrial development has been achieved by relying on fossil fuels for a long time in the past. In order to respond to the depletion of fossil fuels and climate change, the world is trying to build an eco-friendly energy ecosystem. Research on efficiency improvement using renewable energy and ESS in various ways for energy conversion is being promoted. In this paper, a microgrid for industrial complexes was designed, constructed, and demonstrated. It was operated in two modes: an independent mode that each plant generates and uses independently and a connected operation mode that allows energy sharing between factories. In the case of independent mode, PV and PCS were intermittently stopped and restarted according to the status change of SoC section of each site. But, in the case of the connected operation mode, stable power supply was confirmed through power transaction through the operation of the entire SoC. This paper presented and verified an algorithm to stably supply power to industrial complexes consisting of various consumers with different load characteristics.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 춘계학술대회
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• pp.505-508
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• 2006

Recently, concern for tidal power is being increased by newly recycled energy. It is important to decide on the maximum power estimate operation and it's stop by applying the difference of water level between tide level and artificial reservoir for the administration of tidal development. For maximum output of power through turbine generator, administrative variables and process on efficiency of hydraulic turbine and inflow discharge of reservoir is quite complicated because it is run through the connection of discharge-gate and turbine On the development of this model, the administrative process is decided, Operation block is presented for it's maximum power estimate.

• International Journal of Internet, Broadcasting and Communication
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• 제12권4호
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• pp.212-217
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• 2020

We studied on the design of a sprinkler control system that communicates with the administrator's mobile through a wireless communication network and a sprinkler unit that sprays water on the vegetation area. This sprinkler control system consists of a communication module that receives an operation signal for the operation of the sprinkler unit from the administrator's mobile, and a control module that controls the sprinkler unit according to the operation signal received through the communication module. It is also designed to control sprinkler units by measuring temperature, humidity, light intensities, vibration and field images in the vegetation area in real time through sensors and camera for each of them and comparing them with established limit criteria. The sprinkler allows the administrator to control the sprinkler more easily because the administrator operates the sprinkler through the mobile from a distance, and emergency situations occur and can respond quickly.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집B
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• pp.656-661
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• 2000

In the recent trend of electric power supply market, a variable pressure operation supercritical once-through steam generator is highlighted as a thermal power plant for cycling load because of its superiority in load regulation. Almost all thermal power plants of the future are expected to be variable pressure operation supercritical once-through units. APESS(Advanced Plant Engineering & Simulation System) is a dynamic simulation software for power plant which is under being developed by Korea Heavy Industries & Construction Co., Ltd. This paper present the introduction of APESS and the result of simulation for variable pressure operation supercritical once-through steam generator.

• 상하수도학회지
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• 제31권1호
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• pp.63-72
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• 2017

For economic evaluation of integrated operation to sewage facilities, benefit-cost analysis was performed to watershed sewage works project in 7 watershed areas, 156 facilities. In this study, the cost before and after integrated operation was compared and benefits are calculated from the reduction of operators, increasement treated pollution loads, reduction cost through operation convenience, reduction water consumption through effluent reuse, and improvement of life benefit. The result showed that cost was 8,500million won and benefit was 16,747million won, so benefit was 49% higher than cost. B/C analysis result showed that B/C ratio was 1.97 and it is similar to other researches. The benefits of integrated operation included convenience of data management, increase of emergency response, decrease of complains with sewage which was not reflected numerically, so the benefits of integrated operation were expected much greater than this result

• 한국기계가공학회지
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• 제10권5호
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• pp.7-12
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• 2011

This study covers the optimum design of the 5-axis machine tool. In addition, the intelligent control secures structural stability through the optimum design of the structure of the 5-axis machine center, main spindle, and the tilting index table. The big requirement, like above, ultimately leads to speed-up operation. And this is inevitable to understand the vibration phenomenon and its related mechanical phenomenon in terms of productivity and its accuracy. In general, the productivity is correlated with the operation speed and it has become bigger by its vibration scale and the operation speed so far. Vibration phenomenon and its heat-transformation of the machine is naturally occurred during the operation. If these entire machinery phenomenons are interpreted through the constructive understanding and the interpretation of the naturally produced vibration and heat-transformation, it would be very useful to improve the rapidity and its stability of the machine operation indeed. In this dissertation, the problems of structure through heating, stability, dynamic aspect and safety about intelligent 5-wheel machine tool are discovered to examine. All these discoveries are applied to the structure in order to enhance the density of it. It aims to improve the stability.

• Nuclear Engineering and Technology
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• 제48권4호
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• pp.1022-1035
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• 2016

A double-tube once-through steam generator (DOTSG) consisting of an outer straight tube and an inner helical tube is studied in this work. First, the structure of the DOTSG is optimized by considering two different objective functions. The tube length and the total pressure drop are considered as the first and second objective functions, respectively. Because the DOTSG is divided into the subcooled, boiling, and superheated sections according to the different secondary fluid states, the pitches in the three sections are defined as the optimization variables. A multi-objective optimization model is established and solved by particle swarm optimization. The optimization pitch is small in the subcooled region and superheated region, and large in the boiling region. Considering the availability of the optimum structure at power levels below 100% full power, we propose a new operating scheme that can fix the boundaries between the three heat-transfer sections. The operation scheme is proposed on the basis of data for full power, and the operation parameters are calculated at low power level. The primary inlet and outlet temperatures, as well as flow rate and secondary outlet temperature are changed according to the operation procedure.

• 설비공학논문집
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• 제20권2호
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• pp.97-105
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• 2008

This paper presents simulated and experimental test results of optimal control algorithm for an encapsulated ice thermal storage system with full capacity chiller operation. The algorithm finds an optimal combination of a chiller and/or a storage tank operation for the minimum total operation cost through a cycle of charging and discharging. Dynamic programming is used to find the optimal control schedule. The conventional control strategy of chiller-priority is the baseline case for comparing with the optimal control strategy through simulation and experimental test. Simulation shows that operating cost for the optimal control with chiller on-off operation is not so different from that with chiller part load capacity control. As a result from the experimental test, the optimal control operation according to the simulated operation schedule showed about 14 % of cost saving compared with the chiller-priority control.

• 디지털산업정보학회논문지
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• 제15권4호
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• pp.117-129
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• 2019

This study aims to explore a plan for the educational application of K-MOOC brought into relief as a new education system and to draw a direction of improvement for increasing learners' satisfaction through the development and operation of the K-MOOC Course. The colleges produce and provide the MOOC Course as a counterplan through college innovation to respond to social changes due to the reduction of school-age population. Thus, this study selected the target courses for the operation of K-MOOC and proceeded with the development of a course, referring to the guidelines for the development and operation of the K-MOOC Course at the National Institute for Lifelong Education with the quantity for 14 weeks (About 50 minutes per week) for the period of the development of the course of about 5 months. The development of the course was made in the stages of design, development, inspection, and operation. The implications of the operation of K-MOOC obtained through this study are as follows: First, in order to increase the utilization of the MOOC Course, it is necessary to operate it in connection with the regular curriculum; second, it is necessary to have desirable communication to induce the interaction and academic motivation between the instructor and the learners; and third, it is necessary to analyze the relationship of the impact by each background factor through analyzing satisfaction with the lecture and continue to assure the quality of the course through understanding the learners' demands. For this purpose, it is important to experience new attempts directly and analyze the performance of education and the satisfaction of consumers and the instructor in detail, and it is necessary to construct a curriculum suitable for K-MOOC and seek an effective teaching method.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2004년도 춘계 학술대회논문집
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• pp.214-219
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• 2004

The HANARO, a multi-purpose research reactor of 30 MWth, open-tank-in-pool type, has been under normal operation since its initial criticality in February, 1995. The HANARO is composed of inlet plenum, grid plate, core channel with flow tubes and chimney. The reactor core channel is located at about twelve m (12 m) depth of the reactor pool and cold by the upward flow that the coolant enters the lower inlet of the plenum, rises up through the grid plate and the core channel and exit through the outlet of chimney. A guide tube is extended from the reactor core to the top of the reactor chimney for easily un/loading a target under the reactor normal operation. But active coolant through the core can be Quickly raised up to the top of the chimney through the guide tube by jet flow. This paper is described an analytical analysis to study the flow behavior through the guide tube under reactor normal operation and unloading the target. As results, it was conformed through the analysis results that the flow rate, about fourteen kilogram per second (14 kg/s) suppressed the guide tube jet and met the design cooling flow rate in a circular flow tube, and that the fission moly target cooling flow rate met the minimum flow rate to cool the target.