• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.27 no.2
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• pp.204-212
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• 2017

The rotor dynamics and balancing technic for rotating equipment during engineering and manufacture stage are to be carefully considered in order to minimize the operation troubles regarding vibration during commissioning stage. In this paper, the test rig, which includes the disks as balancing plane, is designed and manufactured, so that the characteristic of rotor dynamics can be analyzed such as critical speed and mode shape. The critical speed predicted through natural frequency analysis is verified by the actual measurement on bearing housing vibration during start-up condition of test rig. The low speed balancing and the operating speed balancing test are performed respectively with consideration of first critical speed, and the residual unbalance amounts are estimated in accordance with the relevant method described in API standard. In addition, the single and dual plane balancing are carried out on main disk and trim disk depended on phase information at each balancing step.

• Korean Institute of Interior Design Journal
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• v.22 no.2
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• pp.11-19
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• 2013

Korea Government have carried out various policies to save the Earth environment from global warming and environmental pollution. It has also executed the Green Building Certification Criteria(GBCC) in 2002. The GBCC of office building was executed in 2003 and was revised twice in 2010 and 2011. Concerns about green building construction were quite increasing to keep the building performances sustainable. The aims of this paper is to check the reliability of weighting factors and scoring difficulties in all assessment categories of GBCC and to suggest the amendment direction of the future assessment criteria for green building. For the study, the old and new version of GBCC were examined to present the revision direction of GBCC and the 10 cases certificated by the old and new version, respectively 5 were analysed to compare with the difficulties in obtaining the certification. According to the results of the study, the GBCC requires additional amendments about the assessment categories of the energy consumption monitoring and the building commissioning as required subjects in order to secure the building performances. In addition, the operation mamagement of the building need to be assessed more intensively.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.62 no.1
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• pp.36-44
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• 2013

This paper is written for the development and application of boiler fuel control algorithm and distributed control system of coal-fired power plant by the steps of design, coding, simulation test, site installation and site commissioning test. Fuel control algorithm has the upper algorithm and it is boiler master control algorithm that controls the fuel, feed water, air by generation output demand. Generation output demand by power load influences fuel control. Because fuel can not be supplied fast to the furnace of boiler, fuel control algorithm was designed adequately to control the steam temperature and to prevent the explosion of boiler. This control algorithms were coded to the control programs of distributed control systems which were developed domestically for the first time. Simulator for coal-fired power plant was used in the test step. After all of distributed control systems were connected to the simulator, the tests of the actual power plant were performed successfully. The reliability was obtained enough to be installed at the actual power plant and all of distributed control systems had been installed at power plant and all signals were connected mutually. Tests for reliability and safety of plant operation were completed successfully and power plant is being operated commercially. It is expected that the project result will contribute to the safe operation of domestic new and retrofit power plants, the self-reliance of coal-fired power plant control technique and overseas business for power plant.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.62 no.3
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• pp.117-126
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• 2013

This paper is written for the development and application of boiler furnace pressure control algorithm and distributed control system of coal-fired power plant by the steps of design, coding, simulation test, site installation and site commissioning test. The control algorithms were designed in the shape of cascade control for two parts of furnace pressure control and induced draft fan pitch blade by standard function blocks. This control algorithms were coded to the control programs of distributed control systems. The simulator for coal-fired power plant was used in the test step and automatic control, sequence control and emergency stop tests were performed successfully like the tests of the actual power plant. The reliability was obtained enough to be installed at the actual power plant and all of distributed control systems had been installed at power plant and all signals were connected mutually. Tests for reliability and safety of plant operation were completed successfully and power plant is being operated commercially. It is expected that the project result will contribute to the safe operation of domestic new and retrofit power plants, the self-reliance of coal-fired power plant control technique and overseas business for power plant.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1304-1308
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• 2005

This paper presents the case that the existing analog control systems were retrofitted with digital DCS(Distributed Control System)s for boiler unit in thermal power plant. Replacement of existing worn-out or obsolete analog control systems has been considered. Replacement of existing analog control systems with another analog control systems has lots of difficulties in maintaining the systems due to being out of stock. Due to those difficulties, existing analog control systems have been retrofitted with digital DCSs in many industrial sites. KEPRI(Korea Electric Power Research Institute) accomplished the project that retrofitted analog control systems with the developed DCSs for boiler unit in middle-scale coal-fired thermal power plant. The benefits of an upgrade to digital control include a increase of reliability due to system redundancy, ease of modifying the control logic and the parameters of function block, ease of maintenance due to available spare parts, improvement of information display, ease of modifying MMI(Man Machine Interface) displays, a increase in system availability, and improvement of control performance. This paper describes how to use the parameters of existing analog controllers, the implementation of digital PID controller, control system configuration for boiler unit in thermal power plant, some boiler control loops, control result during commissioning, and the comparison of boiler characteristic test data after retrofitting with the existing test data.

• Korean Journal of Computational Design and Engineering
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• v.16 no.5
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• pp.351-360
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• 2011

Product systems are quickly and frequently changed because Product Life Cycle is continuously reduced and adopting new product is steadily fast. Thus, various studies are progressed using simulation which is one of digital manufacturing. The research that is concerning simulation of control verification for shorten the commissioning which has a lot of trial and error is in progress. Also, simulation of control verification has strength that it can catch the errors in advance. However, a control program in simulation needs virtual factory for representation of control information. For this reason, excessive time and energy is put into controlling the virtual factory. So, in this paper, we construct library which is using exist data, in order to overcome limitation of these problems. Furthermore, we suggest methodology which can model and verify the process more speedy using library. Especially, we give body to the BB/BR Line process which has many altering equipment and need high technology effectively using physical and logical modeling. We can set up a control simulation environment very rapidly, as well as cut process time down using our suggestion.

• Publications of The Korean Astronomical Society
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• v.30 no.1
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• pp.17-29
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• 2015

The IGRINS is a near infrared high resolution spectrograph jointly developed by the Korea Astronomy and Space Science Institute and the University of Texas at Austin. We present design and fabrication of the optomechanical mount for the five mirrors, i.e., an input fold mirror, a slit mirror, a dichroic, and two camera fold mirrors. Based on the structure analysis and the thermal analysis of finite element methods, the optomechanical mount scheme satisfies the mechanical and the thermal design requirements given by the optical tolerance analysis. The performance of the fabricated mirror mounts has been verified through three IGRINS commissioning runs.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.2
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• pp.94.1-94.1
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• 2014

We have carried out IGRINS test observations during its May commissioning run. Our targets were composed of three Luminous Blue Variables (LBVs), one supernova remnant (SNR), and an unidentified stellar source emitting [Fe II] 1.644 um line. In the preliminary results, three LBVs MWC 314, P Cygni, and AFGL 2298 show different characteristics: the spectrum of MWC 314 which is known to be in a binary system clearly shows double-peak structures in hydrogen and iron lines, the P Cygni spectrum reveals the Brackett series of hydrogen emission lines with prominent P-Cygni profiles, and AFGL 2298 likely at its visual minimum phase shows rather different spectrum with relatively weak hydrogen lines. The SNR (G11.2-0.3) was to test the sensitivity of IGRINS for diffuse emission. We successfully detected a dozen H2 emission lines with a velocity width of ~13 km/s, which might indicate a C-shock origin. The unidentified stellar source was one of stellar/compact sources of unknown nature detected in the survey of the Galactic plane in [Fe II] 1.644 um emission line (http://gems0.kasi.re.kr/uwife/). Its spectrum is under investigation. We will present the spectra of test observations and will discuss their scientific significance.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.2
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• pp.93.1-93.1
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• 2014

The reflection nebula NGC 7023 is a typical example of a photodissociation region (PDR), which consists of high density molecular gas that is exposed to an intense UV radiation field. The source of the UV photons in NGC 7023 is the young pre-main-sequence Be star HD 200755. We present our near-infrared high-resolution (R ~ 40,000) spectrum of NGC 7023, covering a region of $1{\times}15$ arcseconds, observed during the commissioning runs of IGRINS (Immersion GRating near-INfrared Spectrometer). The spectrum shows many strong narrow emission lines that arise from the molecular rovibrational transitions of H2. From the intensity ratios between these H2 lines, we investigate physical conditions within the PDR such as the temperature, density, and pressure. The high spectral resolution of IGRINS allows us to resolve the velocity field of the PDR. In addition, we compare the IGRINS spectrum to Cloudy PDR model.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.2
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• pp.92.2-92.2
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• 2014

NGC 6822 is a dwarf irregular galaxy in the Local Group. Unlike clouds in the Large Magellanic Cloud and the Small Magellanic Cloud, molecular clouds in NGC 6822 are not influenced by the Galactic tidal force. Therefore the star forming processes are only dictated by local conditions. Hubble V is the brightest of the several bright H II region complexes in NGC 6822. The core of Hubble V, surrounded by a molecular cloud complex, contains compact clusters of bright blue stars. During the commissioning runs of the new high-resolution near-infrared spectrometer, IGRINS (Immersion GRating near-INfrared Spectrometer), we observed Hubble V and detected many emission lines from the H II regions and from the photodissociation region at the interface between the ionized gas and the molecular cloud. In this presentation, we report preliminary results of the IGRINS observations. We discuss the implications of the observed lines ratios and kinematics for our understanding of the evolution of star forming molecular clouds.