• Journal of Electrical Engineering and Technology
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• v.11 no.2
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• pp.265-273
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• 2016

A water wall system is one of the most important components of a boiler in a thermal power plant, and it is a nonlinear Multi-Input and Multi-Output (MIMO) system, with 6 inputs and 3 outputs. Three models are developed and comp for the controller design, including a linear model, a multilayer feed-forward neural network (MFNN) model and an Echo State Network (ESN) model. First, the linear model is developed by linearizing a given nonlinear model and is analyzed as a function of the operating point. Second, the MFNN and the ESN are developed by using training data from the nonlinear model. The three models are validated using Matlab with nonlinear input-output data that was not used during training.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.654-659
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• 2003

PVAP (Pressure Vessel Analysis Program V1.0) was developed by adopting the finite element analysis program ANSYS V6.0, and Microsoft Visual Basic V6.0 was also utilized for the interfacing and handling of input and output data during the analysis. PVAP offers the end user the ability to design and analyze vessels in strict accordance with ASME Section VIII, Division 2. More importantly, the user is not required to make any design decisions during the input of the vessel. PVAP consists of three analysis modules for the finite element analysis of the primary components of pressure vessel such as head, shell, nozzle, and skirt. In each module, finite element analysis can be performed automatically only if the end user gives the dimension of the vessel. Furthermore, the calculated results are compared and evaluated in accordance with the criteria given in ASME Boiler and Pressure Vessel Code, Section VIII, Division 2. In particular, heat transfer analysis and consecutive thermal stress analysis for the junction between skirt and head can be carried out automatically in the skirt-tohead module. Finally, report including the above results is created automatically in Microsoft Word format.

• Journal of the Korean Institute of Gas
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• v.25 no.3
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• pp.27-38
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• 2021

We devised the system to automatically shutdown the boiler and to fundamentally block the harmful gases, including carbon monoxide, into the indoor when the exhaust system swerves: (1) The discharge pressure of the exhaust gas decreases when the exhaust pipe is disconnected. The monitoring system of the exhaust pipe is implemented by measuring the output voltage of APS(Air Pressure Sensor) installed to control the amount of combustion air. (2) The operating software was modified so that when the system recognizes the fault condition of a flue pipe, the boiler control unit displays the fault status on the indoor regulator while shutting down the boiler. In accordance with the ventilation facility standards in the "Rules for Building Equipment Standards" by the Ministry of Land, Infrastructure and Transport, experiments were conducted to ventilate indoor air. When carbon monoxide leaked in worst-case scenario, it was possible to prevent poisoning accidents. However, since 2013, the number of indoor air exchange times has been mitigated from 0.7 to 0.5 times per hour. We observed the concentration exceeding TWA 30 ppm occasionally and thus recommend to reinforce this criterion. In conclusion, if the flue pipe fault detection and the indoor air ventilation system are introduced, carbon monoxide poisoning accidents are expected to decrease significantly. Also when the manufacturing and inspection steps, the correct installation and repair are supplemented with the user's attention in missing flue, it will be served to prevent human casualties from carbon monoxide poisoning.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.22 no.2
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• pp.451-457
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• 1998

This paper describes a modelling method for SCR(selective catalystic reduction) system in refuse incineration plant. We consider the SCR system as a single input and single output system. For modelling the SCR system, an auto regressive exogeneous(ARX) modelling method is used. In this case, we should design the white noise input for modelling and put it on the system as an input$(NH_3)$, and take an outlet NOx as an output. From these two relations, we design the ARX model with 45 second delay time and transform to a discrete system with sampling time of 0.5 second. Using the obtained SCR model, we verify that the outlet NOx is deeply related with stoker`s moving in boiler of refuse incineration plant.

• Journal of Power System Engineering
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• v.17 no.2
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• pp.87-94
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• 2013

Applicability of organic Rankine cycle for a passenger car with 3.5 L gasoline engine to convert low grade waste heat to useful shaft power has been numerically studied. Working fluid is R134a, and the Rankine cycle is composed of boiler for recovering engine cooling water heat, super heater for recovering exhaust gas heat, scroll expander for converting waste heat to shaft power, condenser for heat emission, internal heat exchanger, and feed pump. Assuming efficiencies of 90% for the heat exchangers, 75% for the scroll expander, and 80% for the feed pump, the Rankine cycle efficiency of 5.53% was calculated at the vehicle speed of 120 km/hr. Net expander shaft output after subtracting the power required to run the pump was 3.22 kW, which was equivalent to 12.1% improvement in fuel consumption. About the same level of improvement in the fuel consumption was obtained over the vehicle speed range of 60 km/hr~120 km/hr.

• Journal of the Korean Institute of Intelligent Systems
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• v.15 no.1
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• pp.24-29
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• 2005

In the fuzzy control for the multi-variable system, it is difficult to obtain the fuzzy rule. Therefore, the parallel structure of the independent single input-single output fuzzy controller using a pairing between the input and output variable is applied to the multi-variable system. However, among the input/output variables which arc not paired the interactive effects should be taken into account. these mutual coupling of variables affect the control performance. Therefore, for the control system with a strong coupling property, the control performance is sometimes lowered. In this paper, the effect of mutual coupling of variables is considered by the introduction of a neuro-fuzzy controller using relative gain matrix. This proposed neuro-fuzzy controller automatically adjusts the mutual coupling weight between variables using a neural network which is realized by back-propagation algorithm. The good performance of the proposed nero-fuzzy controller is verified through computer simulations on 200MW boiler systems.

• Transactions of the KSME C: Technology and Education
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• v.1 no.1
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• pp.129-138
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• 2013

Constant airflow should be kept in order to operate a constant-fired boiler of thermal power plants. Main Bearing Assembly Unit which rotates the ventilation fan does very important role to maintain constant airflow. However, the demand to the output of power is getting increased while the quality level of coal is getting worse than the initial level of design criteria. Especially cost wise operation considering increasing output and the difficulty to supply good quality coal drive increasing supply of low quality coal. As a result, the service life of Main Bearing Assembly is getting shorter till 2~3 years which is just a half of the life of original design. In this study, what causes to shorten the service life of Main Bearing Assembly Unit is analyzed through the reverse engineering and analysis and how to improve the service life more than two times to current situation is explained.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.15 no.4
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• pp.223-229
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• 2022

In this paper, the ignition trans used in boilers was studied. Regardless of the change in the ignition rod length and the ignition rod gap, the output frequency was measured between 59.5 and 61.3 Hz, and it was found that the low frequency circuit operated normally. When the ignition rod gap changed by 2 to 10 mm, the ignition rod length was measured from 2.8A to 3.45A at 30cm. The ignition rod length was measured from 9.37 A to 14.5 A at 500 cm and from 13.2 A to 32.6 A at 1000 cm. As the ignition rod length and the ignition rod gap increased, the current increased. As a result of measuring the secondary coil output voltage. The ignition rod length was measured from AC 0.84 kV to AC 1.75 kV at 30 cm, AC 1.17 kV to AC 1.944 at 500 cm, and AC 1.4 kV to AC 7.18 kV at 1000 cm. As the ignition rod length and the ignition rod gap increased, the output voltage of the secondary coil also increased. As a result of measuring the output voltage of the ignition trans, the ignition rod length was measured from DC 1.11 kV to DC 1.57 kV at 30cm, DC 2.49 kV to DC 3.72 kV at 500cm, and DC 3.78 kV to DC 9.42 kV at 1000cm, and the power voltage increased as the ignition rod length and interval increased.

• Journal of Energy Engineering
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• v.24 no.3
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• pp.13-19
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• 2015

The wood pellet is standardized of woody type fuel which of small cylindrical shape that is produced compress wood remnants in process of woody processing. The pellet is critical energy which expects to increase of the amount used in future. It consumes fuel which of home, common facilities stove and boiler, district heating, and CHP, etc. This study was to develop a movable pellet manufacturing equipment that can be mounted on a truck. The pellet production volume is approximately 309kg per hour, daily output is about 2ton. One days work based on the expected revenue of approximately \268,000 feasibility is considered sufficient.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.321-324
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• 2009

The unpredicted worldwide oil price makes the energy efficiency technology be more importance than any other period. The small cogeneration system is one of the most representative technology among the energy efficiency technologies, and recently, the household cogeneration system has been the center object of attention because of the loss of power transmission and the reasonable energy consumption relative to the household (condensing) boiler producing heat only. A tiny, 1kW of electrical output, gas fueled internal combustion engine cogeneration system was investigated. The electrical efficiency and thermal efficiency of the system were measured. With the emission characteristics, the cogeneration system was analyzed. It was showed the gas engine cogeneration system produced the lowest NOx level compared any other cogeneration system due to the three-way catalyst.