국내 가정용 목재 펠릿 보일러 성능 및 배기 특성 분석

강새별(Sae Byul Kang),김종진(Jong Jin Kim),최규성(Kyu Sung Choi) 대한설비공학회 2009 대한설비공학회 학술발표대회논문집 Vol.2009 No.-

We conducted performance tests of 23.2 ㎾ (20,000 ㎉/h) class domestic wood pellet boilers. The objectives of this paper are 1) to introduce wood pellet and wood pellet boilers, 2) to show the range of thermal efficiency of domestic wood pellet boilers and 3) to let wood pellet boiler manufacturer know the state of technology level of the other wood pellet boiler manufacturer, such as thermal efficiency and flue gas concentration. We conducted 11 performance tests of wood pellet boiler. Average higher heating value of dry wood pellets used to boiler performance tests is 19.2 MJ/㎏ (4,580 ㎉/㎏) and average water content based on wet base is 8.3 %. The test results show that thermal efficiency of domestic wood pellet boiler is about 80.5 % based on lower heating value which is lower than that of domestic gas boiler of 90.7 %. Flue gas temperature is higher than that of domestic gas boilers. Average flue gas temperature of wood pellet boilers is 201 ℃. As temperature of flue gas goes up, the efficiency of wood pellet boiler decreases. We measured O2, CO and NOx concentration of boiler flue gas. The range of CO concentration is 50 ~ 2,000 ppm and NOx concentration is 60 ~ 120 ppm.

목재펠릿 도입에 따른 시설재배의 경제적.환경적 타당성 분석 -목재펠릿과 경유의 비교분석을 중심으로-

양정수,윤성이,Yang, Jeong-Soo,Yoon, Sung-Yee 한국유기농업학회 2013 韓國有機農業學會誌 Vol.21 No.3

With the efforts to development of renewable energy technologies, and increasing awareness to environmental issues, the usage of wood pallets has been increasing every year since the introduction of wood pallet technology to the domestic market. until 2009, majority usage of pellet boiler was in the residential houses. In an effort to increase the distribution of wood pellet boiler to cultivation facilities with high usage of fuels, The Ministry of Agriculture and Forestry has launched a distribution project of wood pellet boiler for fuel usage as a part of the agricultural and fishery energy efficiency projects. Although only small number of farms with a heat-culturing facility have replaced from conventional boiler to pellet boiler. Although part of reason for low usage of pallet boiler is lack of understanding and information of it, the main reasons are high initial cost and uncertainty of its cost efficiency. Also, most people from agricultural industry don't realize it's significance in terms of environmental benefit due to lack of understanding in 'resource circulation' and 'adopting to climate change'. In this study, first, we did a cost-efficiency analysis of the farm which uses a diesel boiler to grow cucumber, tomato, paprika. Then we replaced the diesel boiler to a pallet boiler and measured its cost-efficiency again. By comparing the cost-efficiency of the diesel boiler with the pellet boiler, we analyzed the economic viability of pellet boiler. Then we analyzed viability of pallet boiler usage in terms of 'resource circulation' and 'adopting to climate change'. As a result of our analysis, we have found out that under the current system of government support, the energy usage varies depends of the types crops grown and the higher the energy use, the more cost efficient it is to use the pallet boiler. Also, it is economically viable to use the pallet boiler in terms of 'resource circulation' and 'adopting to climate change'.

목재펠릿 도입에 따른 시설재배의 경제적ㆍ환경적 타당성 분석

양정수,윤성이 한국유기농업학회 2013 韓國有機農業學會誌 Vol.21 No.3

With the efforts to development of renewable energy technologies, and increasing awareness to environmental issues, the usage of wood pallets has been increasing every year since the introduction of wood pallet technology to the domestic market. until 2009, majority usage of pellet boiler was in the residential houses. In an effort to increase the distribution of wood pellet boiler to cultivation facilities with high usage of fuels, The Ministry of Agriculture and Forestry has launched a distribution project of wood pellet boiler for fuel usage as a part of the agricultural and fishery energy efficiency projects. Although only small number of farms with a heat-culturing facility have replaced from conventional boiler to pellet boiler. Although part of reason for low usage of pallet boiler is lack of understanding and information of it, the main reasons are high initial cost and uncertainty of its cost efficiency. Also, most people from agricultural industry don’t realize it’s significance in terms of environmental benefit due to lack of understanding in ‘resource circulation’ and ‘adopting to climate change’. In this study, first, we did a costefficiency analysis of the farm which uses a diesel boiler to grow cucumber, tomato, paprika. Then we replaced the diesel boiler to a pallet boiler and measured its cost-efficiency again. By comparing the cost-efficiency of the diesel boiler with the pellet boiler, we analyzed the economic viability of pellet boiler. Then we analyzed viability of pallet boiler usage in terms of ‘resource circulation’ and ‘adopting to climate change’. As a result of our analysis, we have found out that under the current system of government support, the energy usage varies depends of the types crops grown and the higher the energy use, the more cost efficient it is to use the pallet boiler. Also, it is economically viable to use the pallet boiler in terms of ‘resource circulation’ and ‘adopting to climate change’.

0.5 ton/h급 무연소실 관군 연소 산업용 보일러 개발

강새별(Sae Byul Kang),김종진(Jong Jin Kim),기호충(Ho Choong Ki) 대한기계학회 2007 대한기계학회 춘추학술대회 Vol.2007 No.10

We develop a 0.5 ton/h class non-furnace type industrial boiler. The first non-furnace type boiler was developed and currently is sold from Japan. However, there have been no researches of non-furnace type boiler in Korea. Currently developed non-furnace type industrial boiler has water tubes in a combustion chamber to reduce the boiler size and concentration of NOx. The size of newly developed boiler is about 50% of currently sold commercial fire tube boilers and 120% of the non furnace type boiler which developed in Japan. In order to increase the efficiency of the boiler, an air preheter is placed at the rear of combustion chamber. A fin-tube type heat exchanger and a plate type heat exchanger are adopted to recover thermal energy of the combustion gas. The performance of the newly developed boiler is measured according to Korea Standards regulation (KSB 6205). The rated amount of evaporation is up to 630 kg/h and maximum vapor pressure is 1.0 ㎫ (operation pressure : 0.5~0.8 ㎫). The efficiency based on high heating value is 92% at 80% of boiler load. The concentration of CO is 73 PPM at 100% boiler load and NOx emission is less than 40 PPM.

가정용 목재 펠릿 보일러에 대한 부하별 운전 특성

강새별(Sae Byul Kang),김혁주(Hyouck Ju Kim),박화춘(Hwa Choon Park),심봉석(Bong Seok Sim),김종진(Jong Jin Kim) 대한기계학회 2010 대한기계학회 춘추학술대회 Vol.2010 No.11

Recently domestic wood pellet boilers are installed in rural and forestry houses. The fuel price per lower heating value of wood pellet is about 20 % lower than that of heating oil on July 2010. In spite of lower price of wood pellet, a few user of wood pellet boiler complain expensive fuel cost. One of this reason is inaccurate or improper air-fuel ratio setting of wood pellet boiler. O2 concentration of flue gas of domestic wood pellet boiler is about 9.7 % and there are few domestic wood pellet boiler which can control air-fuel ratio automatically. We tested a domestic wood pellet boiler in changing boiler thermal output. The nominal boiler thermal output is 25 ㎾ (21 500 ㎉/h). We measured thermal efficiency at 100 % boiler thrmal load and in the same air supply condition of 100 % boiler load we measured thermal efficiency at 40, 60, 80 % boiler thermal load. The results show that at boiler load 60 % the thermal efficiency is about 4 % point lower than that of boiler load 100%.

천연가스 사용 난방 및 산업보일러의 NOx와 CO 배출계수 산정 연구

장영기,최상진,김관,송기봉,김호정,정봉진 한국대기환경학회 2004 한국대기환경학회지 Vol.20 No.5

This study was conducted for developing the emission factors of nitrogen oxide(NOx) and carbon monoxide (CO) from the combustion boilers burning liquefied natural gas (LNG). These emission factors were compared with those of U.S. EPA and European Environment Agency (EEA). NOx and CO concentration in the flow gas were measured using Kane-May, KM9106 and Thermo Environmental Instruments Inc., 42C-HL. Measurement were conducted at thirty industrial and commercial LNG boilers. Emission factors were calculated on the basis of fuel consumption (kg-pollutant/㎥-fuel burned). NOx concentration at industrial boiler was 14~125 ppm and it was measured as 35~125 ppm at commercial boiler. NOx emission factors of industrial boiler and commercial boiler were 1.84kg/㎥ and 2.09kg/㎥, respectively. NOx emission factor of commercial boiler was higher than that of industrial boiler. The NOx emission factors estimated in this study were lower than those of U.S. EPA and higher than those of EEA. Average CO emission factor of industrial boiler was 0.65 kg/㎥ and at commercial boiler it was 0.70kg/㎥, CO emission factor at industrial boiler was lower than that at commercial boiler.

선택 실험법을 이용한 친환경 보일러의 시장 점유율 예측

김미정,배정환 한국환경경제학회·한국자원경제학회(구 한국환경경제학회) 2012 자원·환경경제연구 Vol.21 No.3

최근 온실가스 배출 규제와 에너지 안보에 대한 관심이 고조되면서 친환경연료인 목재 펠릿을 이용한 펠릿 보일러가 주목받고 있다. 그러나 친환경 기술인펠릿 보일러는 아직 시장 초기단계로 정부에서 펠릿 보일러에 대한 지원정책을 통해 펠릿 보일러 보급사업을 실시하고 있다. 따라서 펠릿 보일러에 대한 미래시장 점유율을 예측함으로써 정부와 기업이 보다 효과적인 보급정책과 시장전략을 추진할 수 있을 것이다. 이를 위해서는 펠릿 보일러에 대한 소비자 선호를 분석해야 하며 본 연구는 신기술이 갖는 무형의 비용을 반영한 선택실험법을 적용하여 펠릿 보일러에 대한 시장 점유율을 추정하였다. 신기술의 시장 점유율이 확산되고, 기술 신뢰도가 향상됨에 따라 무형의 비용이 감소하게 된다. 상이한 무형의 비용을 가정한 시나리오별로 전기보일러, 가스보일러, 기름보일러, 펠릿 보일러의 선호를 선택 실험법에 의해 조사하였다. 다항로짓모형을 이용하여 속성별 파라메터를 추정하고, 시나리오별로 보일러별 시장 점유율을 예측하였다. 추정결과 무형의 비용이 감소함에 따라 펠릿 보일러의 시장점유율이 점차 증가함을 알 수 있었다. 또한 가스 보일러와 전기보일러에 대한 대체효과가 크게 나타났다. 한편 목재 펠릿 전용 사용자 집단과 일반 보일러 사용자 집단간의 속성별 지불용의액과 시장 점유율에 차이가 발생하고, 소득, 교육, 가족수, 신기술 인식 수준과 같은 개인별 속성에 대해 선호의 이질성이 부분적으로 존재함을 확인하였다. Recently environment-friendly pellet boilers have interests as emissions of greenhouse gases are regulated internationally and energy security becomes more important tooiladdi cted countries including Republic of Korea. But the Korean market for pellet boilers is on the in it ial 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 reflect in gin tangible costs. As the mar k e t share of new technology increases, intangible costs decline. According to different intangible cost scenarios, we experimented people`s preferences on oil, gas, electric, and pelletboilers. 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.

Numerical and experimental study on biased tube temperature problem in tangential firing boiler

Akkinepally, Bhargav,Shim, Jaesool,Yoo, Kisoo Elsevier 2017 Applied thermal engineering Vol.126 No.-

<P><B>Abstract</B></P> <P>In this study, a numerical and experimental investigation on the flow field in a 500-MW unit of a tangentially fired boiler has been performed to understand the effect of residual swirl on the temperature distribution and inconsistency of flow velocity in the crossover pass. The k–k<SUB>L</SUB>–ω turbulence model was used in this study to analyse the possible formation of transition flow in the tangential firing boiler. Furthermore, 1D and 3D hybrid modelling were used for the simulation of the convective heat transfer in the boiler tube assembly. The commercially available code ANSYS Fluent and COMSOL were used for the studies, respectively. The numerical results for the velocity profile and residual swirl in the boiler were validated using the experimental results from the cold air velocity test, in which the flow velocity was directly measured in the full-scale boiler. The computational results agreed well with the experimental findings. Furthermore, from a comparison of the simulation and experiment, it was found that the biased gas flow induces non-uniform tube temperatures at the crossover pass area of the tangential firing boiler. These results aid in the detailed study of the residual swirl effects on the temperature or flue gas at various locations of the boiler. This study indicates that a non-uniform tube temperature at the crossover pass is an inherent problem resulting from residual swirl in the tangential firing boiler. Therefore, the pulverised coal burner should be fine-tuned to avoid tube rupture due to local overheating.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A full-scale CFD simulation was performed for a 500-MW unit of a tangentially fired boiler to determine the flow behaviour. </LI> <LI> The CFD model was validated with experimental results from the cold air velocity test. </LI> <LI> Temperatures of the boiler tube were measured directly in commercial tangential firing boilers. </LI> <LI> Biased temperature profile of the steam and tube is attributed to the non-uniform velocity of the flue gas. </LI> </UL> </P>

Emission Characteristics of PM (PMtotal, PM10, PM2.5), NOx, CO and VOCs Emitted from LNG-fired Gas Turbine and Small Domestic Boiler

김종현,유정훈,송지한,이도영,유명상,황인준,김진성,김종호 한국대기환경학회 2021 Asian Journal of Atmospheric Environment (AJAE) Vol.15 No.4

In recent years, natural gas is increasingly being used in the heating and power generation sectors as a clean fuel with an aim to reduce air pollution. In this study, a standard test method was used to measure air pollutants and identify emission characteristics for gas turbines and small domestic boilers, which use LNG as fuel. For gas turbines, the air pollutants were measured at 14 sites, whereas for small domestic boilers, six of them were installed in a laboratory to run tests due to limitations in on-site measuring and testing. However, the small domestic boilers were all new machines and were operated for long consecutive hours for testing, meaning that the results could vary from that of on-site boilers. The results show that gas turbines and small domestic boilers not only emit PM2.5, but also particulate matters larger than PM2.5. According to the measurements, the average concentration level of PMtotal, PM10, and PM2.5 generated from gas turbines are 51.8, 38.5, and 28.1 μg/m3 (@O2 15%), respectively. Those generated from small domestic boilers were 31.3, 26.2, and 20.0 μg/m3 (@O2 4%), respectively. The NOx concentration levels complied with the emission limits. Especially where a NOx control device was in place, both the NOx and CO concentration levels were relatively low. However, the NOx and CO concentration levels were generated from small domestic boilers were relatively high, since the emission limits were not applied. VOCs were measured at 10 facilities where 28 samples were collected. The compounds that were identified were Aromatics, Oxygenated VOCs, Alkanes, in that order, which were consistent across the samples. Aromatics consisted mostly of toluene, o,m,p-xylenes, benzene, and ethylbenzene. Among oxygenated VOCs, ethyl acetate, vinyl acetate, and isopropyl alcohol, etc. were identified. In other words, gas turbines generated a wider range and higher concentration levels of VOCs compared to small domestic boilers. The emission factors of gas turbines and small domestic boilers were derived from the measurements, and then compared with the standard emission factors of other countries (NAER, U.S. EPA AP-42, EMEP/ EEA). PM emission factors calculated in this study were lower than that of existing emission factors and the calculated NOx emission factors (uncontrolled) for the small boilers were also lower. The CO emission factor for gas turbines was lower than that of existing emission factors, but higher for the small domestic boilers. Emission factors of benzene, toluene, and xylenes, which are hazardous air pollutants, were lower than those of U.S. EPA AP-42.

저에너지 공동주택 개별보일러의 출력범위 조절을 위한 난방 및 급탕부하 분석

김상엽(Kim, Sang-Yeop),장형문(Zhang, Xinwen),김찬희(Kim, Chan-Hee),최지수(Choi, Ji-Su),이규남(Rhee, Kyu-Nam),정근주(Jung, Gun-Joo) 대한건축학회 2021 대한건축학회논문집 Vol.37 No.11

In Korea, it is common to determine the capacity of individual gas-fired boilers based on the floor area or unit heating load of residential buildings. With this approach, the current tendency of heating load reduction can not be taken into account when sizing the individual gas-fired boilers for low-energy apartment buildings. Most of the low-energy apartment buildings might be equipped with over-sized boilers, which would cause the boiler to operate with low efficiency particularly under part load conditions. As the over-sized boilers can deteriorate the energy saving performance of low-energy apartment buildings, this study was conducted to suggest the necessity of adjusting the output range of individual gas-fired boilers. For this purpose, heating and domestic hot water load of apartment buildings were analyzed considering the historical change of energy saving design standards. The analyzed loads were compared with the output range of household gas-fired boilers currently available on the market. The results showed that the heating output of the boilers is over-sized, even though the heating load has been reduced by 53%. It was found that the part-load output of boilers was significantly higher than the heating load, which would lead to the reduced efficiency during the part load conditions. It was also found that the individual room control can increase the difference between the boiler part-load output and heating load. Therefore, it is necessary to adjust the output range of boilers by lowering the part-load output and to increase the turn-down ratio of boilers in order to improve the energy efficiency of low-energy apartment buildings.