• 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.

• The Journal of the Korea institute of electronic communication sciences
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• v.5 no.6
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• pp.645-650
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• 2010

In this research, the problem of combustion and its system in Hyundai Heavy Industries and Sachuan Unison will be analyzed in order to provide some methods of thermal efficiency improvement and help to make a positive influence on fuel savings and their productivity. In forging industries, in order to improve the material properties of the industrial heating elements which are being used, depending on different operation conditions of system equipment and combustion systems, fuel consumption and material properties can get a profound influence. Thus, analyzing about combustion system characteristics of 100 tons heating furnace and heat treatment furnace which are in operation in Hyundai Heavy Industry will be done. In usual, air-fuel ratio is proper for capacity of burner installed in each heating device, otherwise burner gets an automatic turn down ratio. It has a profound influence on heating performance and precision of temperature because it is the fixed characteristics of every industrial furnace. Even if there are some methods to improve the heating performance of a furnace installed with a large capacity burner, it is very difficult to obtain the precision of temperature in maintenance interval. Based on this, performance of burner can be drove to best by improving combustion system. Proper Combustion characteristic for each heating interval was analyzed in heating furnace in Hyundai Heavy Industry. A project plan for improving fuel savings and increasing precision of temperature was presented in this research.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.6
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• pp.658-665
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• 2014

Natural gas for marine diesel engine is considered as an important and clean source of energy because of simultaneously reducing the emission of NOx, SOx and GHG. Especially with a appearance of shale gas, the using of natural gas has been investigated aggressively and expected to expand rapidly. By the reports, gas engine and diesel engine were both in a similar performance in the power aspect, and the SFOC of gas engine was shown a little better than that of diesel engine. But the characteristics of exhaust gas emission were different according to various combustion technologies. And with lean burn technology, the emission of NOx could be reduced to 85% lower than that of diesel engine. In this paper, it was described that a simulation program has been developed to predict NOx emission. The developed program is adopted two-zone model and Wiebe function for combustion in cylinder. The effects of premixed and diffusive combustion could be simulated by using the excess air ratio as input data. And it was confirmed that the results of simulation were agreed with the general trends of exhaust gas emission according to various combustion conditions such as lean burn, premixed and diffusive combustion.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.5
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• pp.101-106
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• 2006

This paper describes performance design of a solid rocket motor on which thrust cut-off system is installed, and evaluates performance of a rocket motor according to a size of TCO ports. TCO system installed on motors was made to carry out firing tests, and the trend of thrust due to various sizes of TCO port was analyzed to find the existence of the port size for maximum reversal thrust. Conservation equations were used to design performance of motors and to analyze test results. This technique for performance design will be usefully applied to the design of similar TCO systems.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.05a
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• pp.53-56
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• 2006

This paper describes performance design of a solid rocket motor on which thrust cut-off system is installed, and evaluates performance of a rocket motor according to a size of TCO ports. TCO system installed on motors was made to carry out firing tests, and the trend of thrust due to various sizes of TCO port was analyzed to find the existence of the port size for maximum reversal thrust. Conservation equations were used to design performance of motors and to analyze test results. This technique for performance design will be usefully applied to the design of similar TCO systems.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2003.10a
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• pp.61-64
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• 2003

A comprehensive understanding is given for the hot-firing test results, which were obtained throughout the verification program of mono-propellant hydrazine thrusters producing 0.95 lbf (4.2 Newtons) of nominal steady-state thrust at an inlet pressure of 350 psia (2.41 ㎫). The scrutiny is made in terms of thrust and temperature behavior of steady state firing mode at the given propellant injection pressures of 400, 250, 100, and 50 psi. Engineering philosophy of data measurement and reduction is shortly mentioned, too.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2003.05a
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• pp.171-176
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• 2003

A Test Facility was established to carry out the integrated propulsion performance tests(IPPT). To perform IPPT's with maximum safety, an emergency blockage system was investigated. An emergency blockage system using combustion chamber pressure and acceleration signals was set up to monitor ignition delay and fail, flame out, propellant feeding status, unstable combustion and excessive structural vibration. With such system, the maximum safety could be secured by rapid judgement and follow-up measures, which made IPPT's be safely completed.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1993.11a
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• pp.22-30
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• 1993

증기분사 가스터빈 시스템의 성능예측 모델을 상용모사기인 ASPEN 코드를 이용하여 개발하였다. 압축기 및 터빈은 등엔트로피 과정으로, 연소기는 Thermal NOx 생성을 수반하는 연소모형으로서 가정하였다. 또한 터빈 냉각을 위한 추출공기량과 냉각공기가 터빈 성능에 미치는 영향은 적절한 상관 관계식을 도입하여 평가하였다. 본 예측 모델을 이용하여 예측된 결과와 실험결과간의 비교를 통하여 모델의 타당성을 제시하였고, 증기 분사량 및 터빈 냉각변수 변화에 따른 예측결과를 통하여 가스터빈 시스템 설계기준을 제시하였다.

• Fire Science and Engineering
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• v.23 no.5
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• pp.66-71
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• 2009

In this study, I evaluated toxicity that analyze performance of flame-retardant about flame-retardant painting wood and combustion gas that is based on the toxicity index. Processing condition of flame retardant solution and treatment method of samples didn't affect greatly to performance of flame retardant. Occurrence of combustion gas showed a almost similar result from the sample which spraying flame retardant solution and toxicity corresponds to high level, Hazard Class III, and the flame retardant solution saturation sample which makes put out Hazard Class II which is a low toxicity relatively.

• Journal of the Korean Institute of Gas
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• v.8 no.3 s.24
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• pp.52-56
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• 2004

Pd catalyst have been used in hydrogenation, oxidation, and low temperature combustion reaction. Recently, it is candidated as a possible reagents in the partial oxidation of methanol reformers of the fuel cell. Pd catalysts, even though it is very precious and expensive, catalytic functioning is good, but it still need to be improved in the matter of durability and low catalytic activity after calcination. In this study, we synthesize the improved Pd catalyst and study their chemical functioning.