• 한국전산유체공학회:학술대회논문집
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• 2009.04a
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• pp.335-340
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• 2009

Operating medium or large scale industrial boilers in partial load condition, the burner should undergo the off-design points resulting in poor exhaust gas characteristics. To obtain the stable turn down performance, two or more burners can be used for the industrial boiler. In case multiple burners are adopted, the heat transfer can be enhanced by arranging the burners properly. In the present study, numerical simulations have been conducted for the combustion chamber of a 2 t/h class industrial boiler in order to clarify the heat transfer characteristics at the combustion chamber.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.33 no.10
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• pp.767-772
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• 2009

The demand for a boiler with low NOx burner is increasing with the recent strict NOx regulation. Staged burner is a common low NOx burner to suppress the formation of thermal NOx by yielding local fuel rich and lean condition. The staged burner gives fire with bigger frontal area and length compared with a conventional burner, which changes heat transfer characteristics in the combustion chamber. The heat transfer and exhaust gas characteristics have been studied in the present study for a 0.5 t/h class furnace type boiler adopting the staged burner. A numerical simulation has been conducted to clarify the detailed physics inside the combustion chamber.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.555-558
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• 2008

The demand for a boiler with low NOx burner is increasing with the recent strict NOx regulation. Staged burner is a common low NOx burner to suppress the formation of thermal NOx by yielding local fuel rich and fuel lean condition. The staged burner gives fire with bigger frontal area and length compared with a conventional burner, which changes heat transfer characteristics in the combustion chamber. The heat transfer and exhaust gas characteristics has been studied in the present study for a 0.5 t/h class furnace type boiler adopting the staged burner. A numerical simulation has been conducted to clarify the detailed physics inside the combustion chamber.

• Journal of computational fluids engineering
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• v.14 no.2
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• pp.77-83
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• 2009

Operating medium or large scale industrial boilers in partial load condition, the burner should undergo the off-design points resulting in poor exhaust gas characteristics. To obtain the stable turn down performance, two or more burners can be used for the industrial boiler. In case multiple burners are adopted, the heat transfer can be enhanced by arranging the burners properly. In the present study, numerical simulations have been conducted for the combustion chamber of a 2 t/h class industrial boiler in order to clarify the heat transfer characteristics at the combustion chamber.

• 한국태양에너지학회:학술대회논문집
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• 2009.04a
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• pp.102-108
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• 2009

Fossil power plants firing lower grade coals or equipped with modified system for NOx controls are challenged with maintaining good combustion conditions while maximizing generation and minimizing emissions. In many cases significant derate, availability losses and increase in unburned carbon levels can be attributed to poor combustion conditions as a result of poorly controlled local fuel and air distribution within the boiler furnace. In order to develop a on-line combustion tuning system, field test was conducted at operating power boiler. During the field test the exhaust gases' $O_2$, NOx and CO was monitored by using a spatially distributed monitoring grid located in the boiler's high temperature vestibule and upper convective back-pass region. At these locations, the flue gas flow is still significantly stratified, and air in-leakage is minimal which enables tracing of poor combustion zones to specific burners and over-fire air ports. using these monitored information we can improving combustion at every point within the furnace, therefore the boiler can operate at reduced excess $O_2$ and gas temperature deviation, reduced furnace exit gas temperature levels while also reducing localized hot spots, corrosive gas conditions, slag or clinker formation and UBC. Benefits include improving efficiency, reducing NOx emissions, increasing output and maximizing availability. Discussion concerning the reduction of greenhouse gases is prevalent in the world. When taking a practical approach to addressing this problem, the best way and short-term solution to reduce greenhouse gases on coal-fired power plants is to improve efficiency. From this point of view the real time optimized combustion tuning approach is the most effective and implemented with minimal cost.

• Journal of the Korean Solar Energy Society
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• v.29 no.5
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• pp.45-52
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• 2009

Fossil power plants firing lower grade coals or equipped with modified system for $NO_x$ controls are challenged with maintaining good combustion conditions while maximizing generation and minimizing emissions. In many cases significant derate, availability losses and increase in unburned carbon levels can be attributed to poor combustion conditions as a result of poorly controlled local fuel and air distribution within the boiler furnace. In order to develop a on-line combustion tuning system, field test was conducted at operating power boiler. During the field test the exhaust gases' $O_2,\;NO_x$ and CO was monitored by using a spatially distributed monitoring grid located in the boiler's high temperature vestibule and upper convective rear pass region. At these locations, the flue gas flow is still significantly stratified, and air in-leakage is minimal which enables tracing of poor combustion zones to specific burners and over-fire air ports. using these monitored information we can improving combustion at every point within the furnace, therefore the boiler can operate at reduced excess $O_2$ and gas temperature deviation, reduced furnace exit gas temperature levels while also reducing localized hot spots, corrosive gas conditions, slag or clinker formation and UBC. Benefits include improving efficiency, reducing $NO_x$ emissions, increasing output and maximizing availability. Discussion concerning the reduction of greenhouse gases is prevalent in the world. When taking a practical approach to addressing this problem, the best way and short-term solution to reduce greenhouse gases on coal-fired power plants is to improve efficiency. From this point of view the real time optimized combustion tuning approach is the most effective and implemented with minimal cost.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.5
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• pp.518-524
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• 2013

In this study, we conducted a study on characteristics of exhaust gas emissions from boiler when water-bunker oil mixed by homogenizer was burned in boiler. The results showed that NOx concentration and CO concentration of the homogenized bunker oil was decreased by 19% and 54% compared to pure bunker oil pretreatment was not being performed. And, in the case of water-bunker A oil, the NOx concentration was decreased with increasing water mixing ratio in bunker A oil. In particular, the NOx concentration in exhaust gas of 20 %water-80 %bunker A oil decrease by 45 % compared with pure bunker-A. However, the CO concentration in exhaust gas of 20 %water-80 %bunker A oil shows irregular changes. This means that the mixing of water more than a certain amount can cause a decrease in combustion performance. From this result, it can be found that critical mixing ratio of water in bunker A oil for normal combustion is 15% in this study. Deposition amount of soot that is collected in the vicinity of the chimney was decreased with increasing water mixing ratio.

• Journal of Biosystems Engineering
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• v.25 no.3
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• pp.221-226
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• 2000

Hot air heater with light oil burner is the most common heater for greenhouse heating in the winter season in Korea. However, since the thermal efficiency of the heater is about 80∼85%, considerable unused heat amount in the form of exhaust gas heat discharges to atmosphere. In order to capture this exhaust heat a heat recovery system for plant bed heating in the greenhouse was built and tested in the hot air heating system of greenhouse. The heat recovery system is made for plant bed or soil heating in the greenhouse. The system consisted of a heat exchanger made of copper pipes, ${\Phi}12.7{\times}0.7t$ located in the rectangular column of $330{\times}330{\times}900mm$, a water circulation pump, circulation plastic pipe and a water tank. The total heat exchanger area is 1.5$m^2$, calculated considering the heat exchange amount between flue gas and water circulated in the copper pipes. The system was attached to the exhaust gas path. The heat recovery system was designed as to even recapture the latent heat of flue gas when exposing to low temperature water in the heat exchanger. According to the performance test it could recover 45,200 to 51,000kJ/hr depending on the water circulation rates of 330 to $690\ell$/hr from the waste heat discharged. The exhaust gas temperature left the heat exchanger dropped to $100^{\circ}C$ from $270^{\circ}C$ by the heat exchange between the water and the flue gas, while water gained the difference and temperature increased to $38^{\circ}C$ from $21^{\circ}C$ at the water flow rate of $690\ell$/hr. By the feasibility test conducted in the greenhouse, the system did not encounter any difficulty in operations. And, the system could recover 220,235kJ of exhaust gas heat in a day, which is equivalent of 34% of the fuel consumption by the water boiler for plant bed heating of 0.2ha in the greenhouse.

• Journal of Energy Engineering
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• v.25 no.3
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• pp.73-82
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• 2016

The energy consumption efficiency in a variety of operational test mode was considered for domestic gas boiler below 70 kW. The energy efficiency test carried out in the experimental conditions similar to the actual operation status was analyzed and compared with the current Korean efficiency test method. Four types of test modes for each boiler(Non-condensing and condensing boiler) were carried out in the condition of laboratory mode(full load, steady state) and actual operating mode. Futhermore divided into two operational status for each of these, it was applied by maximum gas consumption and consumer sales conditions. Test equipment has the function referred to gas boiler standards, such as KS or European standard EN. The equipment should be continuously measured and record the measuring factors which are the flow volume of gas and water, laboratory temperature, water flow volume for heating, return water volume after heating and quantity of the exhaust gases(CO, NO, $NO_2$). The experimental results were found that non-condensing boiler efficiency of laboratory mode is about 10% higher than that of actual mode. In case of condensing boiler, the efficiency of laboratory condition is about 20% higher than that of the actual using conditions. I suggest that the government will gradually take the efficiency test method considering the actual conditions.

• Journal of the Korean Institute of Gas
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• v.12 no.4
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• pp.1-7
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• 2008

In the last five years, 36 people died and 79 were wounded because of carbon monoxide poisoning accident. A CO poisoning accident is higher than any other gas accident in the rate of deaths/incidents. Most of these CO poisoning accidents were caused by defective exhaust tube in the old gas boiler and multi-use facility. In this study, the spread mechanism of CO gas released from leakage hole of exhaust tube was analyzed by concentration measuring test. A CO gas leaked form exhaust tube in a building was the highest concentrated near the ceiling. CO alarm sets installation test confirmed that the alarm sets near the ceiling operated first, and the bottom and middle sets operated after $30{\sim}40$ minutes. Through these experiments, the reasonable installation location of CO alarm was made certain and suggested.