• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.283-286
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• 1996

This study suggests a new methodology for the fault diagnosis based on the signed digraph in developing the fault diagnosis system of a boiler plant. The suggested methodology uses the new model, fault-effect tree. The SDG has the advantage, which is simple and graphical to represent the causal relationship between process variables, and therefore is easy to understand. However, it cannot handle the broken path cases arisen from data uncertainty as it assumes consistent path. The FET is based on the SDG to utilize the advantages of the SDG, and also covers the above problem. The proposed FET model is constructed by clustering of measured variables, decomposing knowledge base and searching the fault propagation path from the possible faults. The search is performed automatically. The fault diagnosis system for a boiler plant, ENDS was constructed using the expert system shell G2 and the advantages of the presented method were confirmed through case studies.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.10
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• pp.101-106
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• 2014

Although anti-freezing heating cable has been widely installed in most residential boiler pipe, there were excessive energy consumption and fire risk due to inadequate temperature control. In this paper, a new energy saving fire risk-free controller was developed by using microprocessing operation which include detection of not only boiler room temperature but also pipe surface one. Its actual effect has been verified to save more than a half of the energy consumption comparing to conventional controller through temperature and humidity chamber experiment.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.9
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• pp.1119-1125
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• 1999

In this paper, a decentralized multilevel-adaptive controller for a boiler-turbine system is designed by using multiple model adaptive method. It is applied to the drum type boiler-turbine system which is simplified from Boryung T/P #1,2 model. A linearlized model is decomposed into three subsystems by means of linear transformation. Then the DMC based on such subsystem is designed and a Multiple Model Adaptive Control(MMAC) scheme is applied for the purpose of the good tracking to variable load demands of the thermal power plant. The good performance of the designed controller is shown by simulations in various conditions that have the large step and ramp change of power demamd.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.10
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• pp.53-66
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• 1994

In this paper, a fuzzy expert system is developed for fault diagnoisis of a drum-type boiler system in fossil power plants. The develped fuzzy espert system is composed of knowledge base, fuzzification module, knowledge base process module, knowledge base management module, inference module, and linguistic approximation module. The main objective of the fuzzy expert system is to check the states of the system including the drum level and detect faults such as the feedwater flow sensor fault, feedwater flow control valve fault, and water wall bube rupture. The fuzzy expert system diagnoses faults using process values, manipulated values, and knowledge base which is built via interviews and questionaries with the experts on the plant operations. Finally, the validity of the developed fuzzy expert system is shown via experiments using the digital simulator for boiler system is Seoul Power Plant Unit 4.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.947-948
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• 2013

• Journal of the Korean Applied Science and Technology
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• v.28 no.4
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• pp.455-463
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• 2011

The average sulfur content of crude oil is 2.2%. Coal is about 0.3 to 4.0 percent of the sulfur gases or particles being discharged into the atmosphere through the chimney as 1 to 2% $SO_3$(Sulfur trioxide) and about 95% of the $SO_2$ is reported. $SO_3$ gas, which has many different causes of, as the combustion of sulfur containing fuel during the air due to the excess $SO_2$ gas is oxidized to $SO_3$ gas. Sulfur trioxide emitted from high sulfur heavy oil fired boiler caused white plume in stack and high temperature and cold end corrosion of facilities. So, in order to control sulfur trioxide concentration of Fuel gas in boiler, various of additives are used in other foreign. They are injected to Fuel Oil and consumed in boiler and reduce ash and the conversion rate of sulfur trioxide. In domestic, MgO compounds are used as additives but the total volume of them are made from other foreign company. In this study, MgO compounds were developed with liquid MgO compounds and field application was accomplished. The effect of newly developed chemicals and process were nearly equal to foreign products. In Consequent, the chemicals and process produced by newly developed technology can be substituted for foreign products and reduce the cost of plant operation.

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.3
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• pp.331-343
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• 2004

The results of individual PAH source profiles that can be applied to receptor model are as follows. The sum of 16 PAH concentrations was 391.41 ng/S㎥ in a tunnel. Phenanthrene was the most abundant compound among 16 PAH, and then pyrene, fluoranthene, anthracene, and naphthalene can be seen in elevated contents. 11,056.61 ng/S㎥ of 16 PAH concentrations in BC oil boiler was two times higher than 6,582.57 ng/S㎥) of those in LNG boiler. Naphthalene was the most abundant compound in both facilities. Phenanthrene, anthracene, and acenaphthylene were the second dominant compound group in order from both facilities. BC oil boiler had relatively high concentration of pyrene compared to LNG boiler that had high concentration of fluorene and did not detect pyrene. The sum of 16 PAH concentrations emitted from MSW incinerators after APCD (air pollution control device) was three times higher than those from MSW incinerators before APCD. However, the concentrations of more than 4-ring PAH compounds (e.g., benzo (a)anthracene) before APCD were higher than those after APCD. This fact implies that PAHs generated by combustion process are eliminated in APCD and they are continuously produced in stack or atmosphere by PAHs precursors.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.10a
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• pp.101-106
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• 2011

In the present paper, the phenomena of abnormal noise and vibration due to acoustic resonance of CFBC(Circulating Fluidized Bed Combustion) boiler was presented. The acoustic resonance which occurred in the gas path of CFBC boiler system was caused by coincidence of vortex shedding frequency of tube bank and acoustic natural frequency of duct and hopper. And, the phenomena of beating arose from the interference of two closed resonant waves at 66.4Hz and 70.8Hz. There are two control methods for acoustic resonance in this system. The first method is to change the vortex shedding frequency from the structural alterations on the tube bank. And the second method is to change the acoustic natural frequency of the gas path with the installation of anti-noise baffles. The second one which is relatively easy to apply, was adapted in this study. As a result, the noise and vibration level have been decreased by 41dB and 94% at 66.4Hz, respectively. And the improvement of noise and vibration at 70.8Hz was identified by sensory evaluation.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.13 no.2
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• pp.102-110
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• 1999

The aim of this paper is to suggest a design method of the optimal model following control system using gerelic algoritlun (GA). This control system is designed by applying GA with reference model to the optimal determinination of weighting matrices Q, R that are given by LQ regulator prooblem. The method to do this is that all the diagooal elements of weighting matrices are optimized simultaneously by GA, in the search domain selected adequately. And, we design the mxiel following control system to boiler-turbine equipment by the proposed mothod. The model following control system designed by this mothod has the better command tracking perfannaoce than that of the control system designed by the trial-and-error method. The effectiveness of this cootrol System is verified by computer simulation.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.1
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• pp.126-132
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• 2012

This paper suggests a design method of the model-following H${\infty}$ control system having robust performance. This H${\infty}$ control system is designed by applying genetic algorithm(GA) with reference model to the optimal determination of weighting functions and design parameter ${\gamma}$ that are given by Glover-Doyle algorithm which can design H${\infty}$ controller in the state space. These weighting functions and design parameter ${\gamma}$ are optimized simultaneously in the search domain guaranteeing the robust performance of closed-loop system. The effectiveness of this H${\infty}$ control system is verified by applying to the boiler-turbine control system.