• 한국연소학회:학술대회논문집
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• 2012.04a
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• pp.41-42
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• 2012

Circulating fludized bed(CFB) furnace which can use a variety of low-grade fuels because of high heat capacity and good mixing characteristic in its furnace have turned out to be effective system. There is no many research to design CFB boiler in korea. thus, we feel necessity to research design method. So far accurate hydrodynamics and combustion mechanism information in CFB furnace has been lacked. Therefore, design method that derives design parameter is being made. so, this study is aimed to derive design parameters of CFB furnace from heat and mass balance by using existing plant data.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2934-2939
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• 2008

We conducted a test of a direct burning of crude Jatropha oil (CJO) in a commercial boiler system. The fuel, crude Jatropha oil is not biodiesel which comes from transeterification process of bio oil, but it is pure plant oil. The higher heating value (HHV) of the CJO is 39.3 MJ/kg (9,380 kcal/kg) and is higher than that of a commercial heating oil, 37.9 MJ/kg. The kinematic viscosity of CJO is 36.2 mm2/s at $40^{\circ}C$ and 8.0 mm2/s at $100^{\circ}C$. The burner used in the test is a commercial burner for a commercial heatingoil and its capacity is 140 kW (120,000 kcal/h). We did a preliminary test whether the combustion is stable or not. The preliminary test was a kind of open air combustion test using the commercial burner with crude Jatropha oil. We found that the combustion can be stable if the crude Jatrophaoil temperature is higher than $90^{\circ}C$. We measured the flue gas concentration by using a gas analyzer. The NOx concentration is $80{\sim}100\;ppm$ and CO concentration is nearly 0 ppm at flue gas O2 concentration of 3.0 and 4.5%.

• Journal of ILASS-Korea
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• v.10 no.3
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• pp.9-16
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• 2005

To investigate spray and combustion of emulsified fuel of W/O type, we mixed water with light oil by using ultrasonic energy adding system. We measured the SMD of sprayed droplet to find atomization characteristics of emulsified fuel with using the Malvern 2600D system. Major parameters are the weight ratio of water($0{\sim}30%$ by 10%) in emulsified fuel injection pressure(lobar), and the measurement distance($10{\sim}100mm$ by 10mm). Combustion visualizing system is made up commonly used boiler system and digital camera 1/500s to investigate combustion phenomena. As a result, the more water contents increased, the more SMD increased. The water particle of emulsified fuel made short flame in continuos spray combustion phenomena because of micro explosion.

• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.5
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• pp.424-431
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• 2007

This thesis proposed H-Bridge Multi-Level Inverter for Fluidized Bed Combustion Boiler Secondary Air Fan in 200MW thermal power plant. The adjustable speed drive systems improve the efficiency in lightly load condition and extend the life span of motor by limiting the over current at starting. H-Bridge Multi-level Inverter is composed of the several series low voltage power cell inverters, which have the independent isolated do link, in each phase. KEPRI(Korea Electric Power Research Institute) has successfully completed to develop, install, and commission H-Bridge Multi-level Inverter(6.6kV, 1MVA). This thesis gives a full detail about H-Bridge Multi-level Inverter, proposed boiler DCS(Distributed Control System) logic, and commissioning test result.

• Journal of the Korea Organic Resources Recycling Association
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• v.14 no.3
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• pp.85-90
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• 2006

The purpose of this research is to design an imitation boiler similar to the waste heat boiler installed on a plasma melting furnace in order to acquire a capability of a thermal design as to the circulation of heat and the discharge of noxious gas inside a boiler and to improve the efficiency of a waste heat boiler using the CFD (Computation Fluid Dynamics) program. The position of corrosion and the generation of a clinker inside a boiler due to temperature changes, combustion gas flows, and corrosive gases inside a boiler are examined to design the structure of an efficient boiler and recycle energy. As a result of this research, the boiler installed on a plasma melting furnace met the conditions of design by cooling the combustion gases discharged after the second combustion from an exhaust port, originally at 1,200 degrees Celsius, down to around 450 degrees Celsius. On the other hand, the circulation of corrosive gases (SOx and HCL) may lead to the generation of corrosion or a clinker in the upper and lower parts of an exhaust port more easily than any other parts of a boiler. Accordingly, the corrosion on the inside and outside walls of a boiler may result in a shortened lifespan of a boiler and an inability to recycle waste heat in an efficient manner. A prevention against corrosion at high and low temperatures needs to be considered in detail.

• Journal of the Korean Society of Combustion
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• v.23 no.1
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• pp.44-54
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• 2018

Heat and mass balance process modeling has been conducted for a coal-firing power plant to be used as a testbed facility for development of various plant systems and equipment. As the material and design of the boiler tube bundle and fuel conversion to the biomass have become major concerns, the process modeling is required to incorporate those features in its calculation. The simulation cases for two different generation load show the satisfying results compared to the operational data from the actual system. Based on the established process conditions, the hypothetical case using wood pellet has also been simulated. Additional calculations for the tube bundle has been conducted regarding the changes in the tube material and design.

• Journal of the Korean Society of Combustion
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• v.4 no.1
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• pp.67-83
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• 1999

The objective of this study is development of low emission pulverized coal combustor for reducing pollutant emission generated from coal combustion. Low emission combustion technology for reducing NOx and fly ash was investigated by using 2 stage coaxial cyclone combustor. Staged combustion was employed for NOx reduction and high temperature slagging combustion was also studied for fly ash removal in the combustor. The result of this study shows that the low emission combustion system can reduce the amount of atmospheric pollutions with improved boiler efficiency and performance.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.1031-1035
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• 2008

The importance of the more efficient cogeneration system is emphasized. Also the more clean energy is needed at recent energy system. The cogeneration system using Lean burn engine is more preferred to the system using Rich burn engine because of the electrical efficiency. Although the cogeneration system using Lean burn engine is economically preferred, because of the NOx emission level, the system using Rich burn engine with 3-way catalyst can only be used in Korea. The NOx regulation level is 50ppm at oxygen level 13%. The cogeneration hybrid system is consist of Lean burn gas engine, afterburner, boiler, economizer, DeNOx catalyst, combustion catalyst, absorption chiller, cooling tower and grid connection system. The system was accurately evaluated and the result is following ; 90% total efficiency, below 10ppm NOx, 50ppm CO, 25ppm UHC. The cogeneration hybrid system can meet the NOx level and exhaust gas regulation. It can achieve the clean combustion gas and efficient cogeneration system.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.3
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• pp.157-166
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• 2009

The pulverized coal combustion behavior in the coal fired utility boiler has been investigated with the CFD and process analysis techniques. The used commercial software were CFX and PROATES, and these were coupled each other to get more reliable boundary condition set-up, resulting in more reliable solution. For two cases which were the actual operation condition of A power plant, the calculated values from the coupled CFD and process analysis for thermal energy system were compared with the plant data, and the good agreements were obtained for Case 1 and 2. The calculated temperature distributions on the surface of heat exchangers were compared with the plant data for the steam temperatures across heat exchangers, and these explained the actual operating situation very well. The temperature deviation across the final superheater tube, which was believed to be the main cause of the frequent tube failure, were also explained very well with the calculated distributions of gas temperature and radiation on the plane of the final superheater.

• 한국연소학회:학술대회논문집
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• 2001.06a
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• pp.172-179
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• 2001

Experimental studies have been carried out to find out the characteristics of the heat transfer, combustion emission and noise in the boilers without any extra firing zone for complete combustion of fuel. For the experiments a burner of premixed type and some heat exchangers were designed and manufactured. Also test facilities including a data acquisition system and various measuring devices were set up in order to measure automatically the various temperatures and flow rates of water and combustion gas. Various experiments were performed to find out the heat transfer characteristics as well as combustion emission and noise. In general, the burner which has uniform holes in the burner nozzle plate generates big combustion noise . whistling. The noise reduction method is discussed in this study. Many experimental data such as noise level, the amount of pollutant emission and heat transfer rate for different combination of heat exchangers are given as comparison bases for numerical studies.