• Environmental and Resource Economics Review
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• v.21 no.3
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• pp.595-625
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• 2012

Recently environment-friendly pellet boilers have interests as emissions of greenhouse gases are regulated internationally and energy security becomes more important to oil addicted countries including Republic of Korea. But the Korean market for pellet boilers is on the initial stage due to the high production costs relative to other conventional boilers. Hence the Korean government has supported financially and promoted the pellet boiler business. In this sense, it would contribute market stratergy and effective promotion policy for both of the government and private companies if we can forecast market shares of pellet boilers appropriately. For this purpose, this study surveyed potential consumers' preferences on pellet boilers among various alternatives using a choice experiment reflecting intangible costs. As the market share of new technology increases, intangible costs decline. According to different intangible cost scenarios, we experimented people's preferences on oil, gas, electric, and pellet boilers. A multinomial logit model was employed to estimate coefficient parameters of common attributes for various alternative boilers. Based on the estimates, we forecasted market shares of individual boilers. We found that as intangible costs decline, the market share of pellet boiler increase substantically while market shares of electric and gas boilers decrease dramatically. The market share of oil boiler did not change significantly. Meanwhile, as people are more rich, more educated, and exposed to advertisement on pellet boilers, the likelihood of choosing the pellet boiler increases.

• 보일러설비
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• s.196
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• pp.104-107
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• 2010

• Journal of Energy Engineering
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• v.23 no.3
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• pp.211-220
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• 2014

This study reports the formation characteristics of tar, ash and clinker due to a wood pellet grade and the performance analysis of wood pellet boiler in terms of the moisture contents change of the wood pellet. Tar was accumulated on the heating surface according to combustion of wood pellet, the ash was yielded on the floor of combustion chamber in a wood pellet boiler and the clinker was solidified at the burner due to combustion of the 3rd grade wood pellet. Especially, the moisture contents is important factor to define the grade. Wood of logging residues has a non-uniform moisture contents after the field process, yields of tar, ash and clinker are increased in case of combustion due to the high ash contents. For these reasons, emission of harmful compounds in the exhaust gas, decrease of boiler efficiency and the system operating errors are observed. In the performance analysis of wood pellet boiler in terms of the moisture contents change of the 1st grade wood pellet, the boiler efficiency was reduced by 27.08% with 6.6% moisture contents increase. The optimum moisture contents of wood pellet is needed to improve the boiler performance and efficiency.

• Journal of Energy Engineering
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• v.23 no.3
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• pp.203-210
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• 2014

In this study, combustion behaviour were to analyze by comparing experimental data against predicted values. In developing pellet boiler performance, various factors such as combustion chamber shape, input air velocity, the amount of fuel, temperature, and fuel characteristics need to be analyzed. Analytical model using a numerical method is useful to overcome time and cost consuming by practical experiment. By controlling feeding rate of fuel, flue gas composition and temperature distribution obtained form experiment were compared with predicted values using FLUENT(ANSYS, Inc., Southpointe). Measurement were in good agreement with model predictions : with 0.60 % for $CO_2$ 0.73% for $O_2$ when compared with independent data sets.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.34-34
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• 2017

목질계바이오매스 중 목재펠릿은 '탄소중립(Carbon Neutral)' 연료로써 온실가스 감축 의무에 대응 가능한 에너지원이다. 하지만 목질계바이오매스 연소 시 발생되는 타르는 보일러 내부에 누적되어 효율을 감소시킨다. 타르 및 연소 불꽃에 의한 효율 감소를 최소화하기 위해 반대측면에 내화재(Castable)를 적용하여 실험하였으며 시뮬레이션을 이용하여 구조변경 분석이 실시되었다. 적용된 내화재는 비중이 낮고 단열성이 우수하여 열손실을 막아 연료비 절감의 효과를 가져 오며, 연소실 내부 청소 면적 감소로 인한 경제적 효과도 기대 할 수 있다. 분석결과를 이용하여 최적화된 펠릿보일러가 제작되었으며, 실험을 통하여 200시간 가동 후 열효율 감소량이 나타났다. 단위시간별 동일한 외부환경(산화제량, 부하, 주변 온도, 펠릿소비량)에서 실험이 진행 되었으며, 타르생성이전(Non-tar), 이후(Tar-existence) 보일러의 열효율 성능 비교실험이 실시되었다. 실험결과 타르생성이전 조건에서 구조변경 전 후 보일러의 열효율은 각각 91.87%, 90.73%로 확인되었으며, 타르생성이후 조건에서 각각 82.68%, 83.27%의 열효율을 확인하였다. 타르생성이전 대비 이후 조건에서 열효율 감소량은 각각 9.19%p, 7.46%p로 구조변경 전 대비 변경 후 보일러의 열효율이 약 1.73%p 더 적게 감소됨을 확인되었으며, 시뮬레이션 결과 타르생성이전 조건에서 구조변경 전 후 보일러의 효율은 각각 91.83%, 92.05%로 확인되었으며 타르 생성이후 조건에서 각각 85.25%, 87.43%의 열효율을 확인하였다. 타르생성이전 대비 이후 조건에서 열효율 감소량은 각각 6.58%, 4.62%로 구조변경 전 대비 변경 후 보일러의 열효율이 약 1.96%p 더 적게 감소됨을 확인하였다.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.45 no.8
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• pp.22-31
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• 2016

• Proceedings of the Korea Forestry Energy Research Society Conference
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• 2011.02a
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• pp.90-91
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• 2011

• Journal of Energy Engineering
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• v.24 no.2
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• pp.120-128
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• 2015

This study reports the combustion characteristics, such as burner temperature and the concentration of exhausted gas ($O_2$, $CO_x$, $NO_x$) due to the different types and pitches of the fuel supply feeder of the wood pellet boiler. The 1st grade wood pellets composed of mainly larch have been used for the experiment. In case of using the spring feeder, mean temperature of burner was approximately $821.76^{\circ}C$, and the mean concentration of oxygen, carbon monoxide, carbon dioxide and nitrogen oxide were approximately 8.88%, 93.35ppm, 12.15% and 139.83 ppm, respectively. The test result with the spring feeder was shown to approach the condition of complete combustion compared to that of a screw feeder and were in good agreement with authentication judgement standard. Furthermore, the combustion efficiency was improved according to the growth of screw pitch. The control of air flow rate from the blower and ventilator is needed to achieve the complete combustion.

• Journal of Applied Reliability
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• v.13 no.1
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• pp.31-44
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• 2013

Recently, due to the high rise of energy costs and environmental problem issues, much attention has been paid to wood pellets. Wood pellets are produced by compressing woody biomass into cylindrical form. Wood pellets are suitable for use at various scales in industrial furnaces for heat production to replace conventional fossil fuel energy sources since the use of wood pellet that is carbon neutral can alleviate global warming. This study presents the result of developing two industrial wood pellet boilers with high safety having capacities of 290kW and 440kW. Efficiency has been improved by using a rotating screw bar grate burner. Special attention has been paid to the improvement of the safety of the wood pellet boilers from backfire by adopting a triple protecting system composed of a rotary feeder, an air curtain, and a backfire protecting DC-fan.

• Journal of Applied Reliability
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• v.12 no.1
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• pp.35-46
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• 2012

Wood pellet is one of biomass energy fuels, which is produced by compressing woody biomass such as sawdust, planer shavings, and whole-tree removal or tree tops and branches leftover after logging into cylindrical form. Latterly much attention has been paid to wood pellet boiler which is suitable for use at various scales in domestic and industrial furnaces for heat production to replace conventional fossil fuel energy sources since the use of wood pellet that is carbon neutral can alleviate global warming. This study presents the result of developing a high efficiency wood pellet boiler with 55MJ/h capacity. Efficiency has been improved by using a rotating disk burner with a shorter screw feeder. Special attention has been paid to the improvement of the safety of the wood pellet boiler from backfire by adopting a double protecting system composed of a shutter and an air curtain. The result shows that the efficiencies of the wood pellet boiler are 97.2% and 89.2% based on lower and higher heating values, respectively, at 15.1kW of heating output.