• 한국연소학회지
• /
• 제18권2호
• /
• pp.8-16
• /
• 2013

The flameless combustion has been considered as one of the promising combustion technology for high thermal efficiency, reducing NOx and CO emissions. In this paper, the effect of air and fuel injection condition on formation of flameless combustion was analyzed using three dimensional numerical simulation. The results show that the high temperature region and the average temperature was decreased due to increase of recirculation ratio when air velocity is increased. The average temperature was also affected by entrainment length. Generally mixing effect was enhanced at low entrainment length and dilution was dominated at high entrainment length. This entrainment length was greatly affected by air and fuel injection velocity and distance between air and fuel. It is also found that the recirculation ratio and dilution effect were generally increased by entrainment length and the recirculation ratio, mixing and dilution effect are the significant factor for design of flameless combustion system.

• 동력기계공학회지
• /
• 제16권3호
• /
• pp.44-50
• /
• 2012

The reliability qualification test is essential in order to ensure the life time of the product under the normal operation conditions when a new product is developed. The reliability qualification test period has an important impact on the development time of new product. Therefore, some researches to reduce the test time of reliability qualification test have been actively studied. Generally, accelerated life test is well known as one method that can save the test time of the reliability qualification test. This test is conducted under the higher stress condition than normal condition. So we need to investigate what factor affects to the higher stress condition. This paper shows the relationship between the acceleration factor and reliability qualification test period. Especially, we focused on the method to obtain effective acceleration factors under the high temperature condition. Through some experiments for a refrigerator's compressor, we were able to confirm how to increase acceleration factors and how to reduce the reliability qualification test period with minimum samples.

• 대한설비공학회지:설비저널
• /
• 제23권5호
• /
• pp.361-377
• /
• 1994

• 한국대기환경학회:학술대회논문집
• /
• 한국대기환경학회 2010년도 춘계학술대회 논문집
• /
• pp.162-164
• /
• 2010

• 대한설비공학회지:설비저널
• /
• 제18권3호
• /
• pp.206-219
• /
• 1989

• Journal of Mechanical Science and Technology
• /
• 제16권7호
• /
• pp.950-958
• /
• 2002

The combustion characteristics of a low NOx burner using reburning technology have been experimentally studied. The return burner usually has three distinct reaction zones which include the primary combustion zone, the reburn zone and the burnout zone by provided secondary air. NOx is mainly produced in a primary combustion zone and a certain portion of NOx can be converted to nitrogen in the rebury zone. In the burnout zone, the unburned mixtures are completely oxidated by supplying secondary air. Liquefied Petroleum Gas (LPG) was used as main and reburn fuels. The experimental parameters investigated involve the main/reburn fuel ratio, the primary/secondary air ratio, and the injection location of rebury fuel and secondary air. When the amount of return fuel reaches to the 20-30% of the total fuel used, the overall NO reduction of 50% is achieved. The secondary air is injected by two different ways including vertical and parallel injection. The injector of secondary air is located at the downstream region of furnace for a vertical-injection mode, which is also placed at the inlet primary-air injection region for a parallel-injection mode. In case of the vertical injection of the secondary air flow, the NOx formation of stoichiometric condition at a primary combustion zone is nearly independent of the rebury conditions (locations, fuel/air ratios) while the NOx emission of the fuel-lean condition is considerably influenced by the reburn conditions. In case of the parallel injection of the secondary air, the NOx emission is sensitive to the air ratio rather than the fuel ratio and the reburning process often coupled with the multiple air-staging and fuel-staging combustion processes.

• 한국마린엔지니어링학회:학술대회논문집
• /
• 한국마린엔지니어링학회 2006년도 전기학술대회논문집
• /
• pp.35-36
• /
• 2006

This study is mainly concerned with vibration control of L-type reciprocating air compressor by a dynamic vibration absorber. The dynamic vibration absorber of reciprocating air compressor was designed for constant revolution running condition. For the review, Vibration test was conducted for the performance appraisal of installed dynamic vibration absorber in the reciprocating air compressor. As a result of the test, the performance of dynamic vibration absorber was satisfactory.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1996년도 추계학술대회 논문집
• /
• pp.496-500
• /
• 1996

An air flow measurement device is proposed. The thermal characteristic of a semiconductor element is adopted as a cooling parameter of thermal convection rate. The difference between forced convection and natural convection of two Zener diodes results enough difference in temperature. Experiment at various air flow conditions shows the measuring capability of the air flow in a duct. This measuring device has some merits, such as a reliability n hard field condition, simple circuit for signal processing, small volume of the element, less air flow resistance, independance of various ai temperature. The experimental result shows that it is an exact and usefull air flow measurement device.

• 한국주거학회논문집
• /
• 제15권3호
• /
• pp.101-108
• /
• 2004

To find more efficient exhaust effect, air curtain of upward or downward trend in gas table and left or right side of range hood were made. As result that film vapor from range hood lower part by digital camera, the air current change by moving existence and nonexistence of exhaust fan and direction of air curtain were known. Under all experiment condition, upward air curtain superior exhaust performance.

• 한국콘텐츠학회논문지
• /
• 제16권2호
• /
• pp.143-151
• /
• 2016

사람들이 집, 회사 등에서의 실내생활이 증가함에 따라 실내 공기오염에 대한 관심도가 높다. 본 논문에서는 실내 공기오염 중 인체에 가장 영향을 많이 미치는 이산화탄소, 미세먼지, 생활용품에서 발생되는 휘발성유기화합물(VOCs)를 측정할 수 있는 실내 공기오염 측정 시스템을 제안한다. 제안된 시스템은 실내 공기오염을 측정하는 디바이스, 정보를 저장하고 전송 할 수 있는 웹서버, 오염정보를 확인할 수 있는 안드로이드 어플리케이션으로 구성되어 있다. 본 시스템의 성능 확인을 위하여 초와, 담배연기 두 가지 시료의 실험을 통해 실내 공기 상태 변화를 어플리케이션으로 확인하였다. 또한, 외부 대기 상태와 디바이스로부터 측정된 내부 대기 상태를 비교할 수 있도록 시각화함으로써 사용자의 편의성을 증대시킬 수 있을 것으로 판단된다.