• Journal of Energy Engineering
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• v.22 no.2
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• pp.169-174
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• 2013

An experimental study has been conducted for the design of the regenerative oxy-fuel combustion system with ceramic ball. Various design parameters are considered such as ball size, regenerator weight, and combustion load. Regenerative system with a pair of oxygen burners and regenerators is set up and the temperature of oxygen and exhaust gas passing through ball regenerator is measured. It is shown that the temperature distributions with time are affected by ball diameter and regenerator weight, and the significant temperature change is observed by combustion load. As the ball size decreases and the regenerator weight increases, the regenerating temperature efficiency increases. It is found that the heat recovery ratio is low despites of high regeneration temperature efficiency.

• Journal of Energy Engineering
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• v.12 no.1
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• pp.35-41
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• 2003

Heat regenerator occupied by regenerative materials improves thermal efficiency of regenerative combustion system through the recovery of heat of exhaust gaset. By using one-dimensional two-phase fluid dynamics model, the unsteady thermal flow of heat regenerator with spherical particles, was numerically simulated to evaluate the heat transfer and pressure drop and thereby to suggest the parameter for designing heat regenerator. It takes about 7 hours for the steady state of the flow field in regenerator, in which heat absorption of regenerative particle is concurrent with the same magnitude of heat desorption. The regenerative particle experiences small temperature fluctuation below 10 K during the reversing process. The performance of thermal flow in heat regenerator varies with inlet velocity of exhaust gas and air, configuration of regenerator (cross-sectional area and length) and diameter of regenerative particle. As the gas velocity increases, the heat transfer between gas and particle enhances and with the increase the pressure losses. As particle diameter decreases, the air is preheated higher and the exhaust gases are cooled more with the increase of pressure losses.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.11a
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• pp.43-46
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• 2006

Storage air heater(SAH) is a general purpose facility that is used to simulate the high altitude condition of supersonic ground test facility, thurst compensation test of rocket engine nozzle and gas turbine engine combustor test. SAH in KARI is built to simulate the total temperature of the supersonic ground test facility which has a wide flight envelope from altitude 0km, Mach 2 to altitude 25km, Mach 5 and operates up to 1300K, 3.5MPa. In this paper, we introduces the SAH in JAXA which is model of SAH in KARI and summarizes the design process and manufacture of ours.

• 한국연소학회:학술대회논문집
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• 1999.10a
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• pp.189-200
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• 1999

Combustion characteristics of a regenerative combustor for high temperature air combustion have experimentally studied. Temperature measurement on regenerative ceramic material and combustor has been carried out with changing equivalence ratio at constant turn-over period. Stable and unstable combustion region have been found and also detailed averaged temperature profile with respect to various air flow conditions have been obtained.

• 한국연소학회:학술대회논문집
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• 2013.06a
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• pp.13-14
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• 2013

The aim of this study is to investigate the parametric characteristics on regenerative system with oxy-fuel combustion by experiment. Regenerative system with a pair of oxygen burners and regenerators is used for evaluating regenerator characteristics according to design parameters such as ball (regenerator medium) size, regenerator weight, and bypass of exhaust gas. The temperature profiles with time are varied by ball size and regenerator weight. The bypass of exhaust gas shows that the heat recovery ratio increases while the regenerating temperature efficiency slightly decreases.

• Journal of computational fluids engineering
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• v.18 no.3
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• pp.1-7
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• 2013

A pure oxygen combustion technology is crucial in Carbon Capture and Storage (CCS) technology especially in capturing of $CO_2$, where CCS will reduce 9 $GtCO_2$ by 2050, which is 19% of the total $CO_2$ reduction amount. To make pure oxygen combustion feasible, a regenerative system is required to enhance the efficiency of pure oxygen combustion system. However, an existing air combustion technology is not directly applicable due to the absence of nitrogen that occupies the 78% of air. This study, therefore, investigates the heat and fluid flow in a regenerative system for pure oxygen combustion by using commercial CFD software, FLUENT. Our regenerative system is composed of aluminium packed spheres. The effect of the amount of packed spheres in regenerator and the effect of presence or absence of a bypass of exhaust gas are investigated. The more thermal mass in regenerator makes the steady-state time longer and temperature variation between heating and regenerating cycle smaller. In the case of absence of bypass, the regenerator saturates because of enthalpy imbalance between exhaust gas and oxygen. We find that 40% of exhaust gas is to be bypassed to prevent the saturation of regenerator.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1998.05a
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• pp.77-82
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• 1998

현재 온실 난방에 주로 이용되고 있는 난방기는 대부분이 화석에너지를 연료로 사용하고 있다. 따라서 생산비의 가중이 불가피하며, 또한 연소 과정에서 발생하는 배기 가스로 인하여 환경 오염이 문제시되고 있다. 따라서 태양에너지를 보다 더 적극적으로 활용할 수 있는 기술의 개발이 요구된다. 태양에너지를 시설 농업에 적극적으로 이용하기 위해서는 주간에 밀도가 낮은 태양에너지를 고밀도로 축열하여 기온이 급강하하는 야간의 보온에 활용하여야 한다. 주간의 온실내 잉여 태양에너지를 축열할수 있는 상변화 온도 3$0^{\circ}C$ 수준의 잠열축열재를 개발하기 위하여 수행한 본 연구의 결과를 요약하면 다음과 같다. 1. SCD에 Borax를 0.0~5.0wt% 첨가하여 과냉도를 25.$0^{\circ}C$에서 $1.5^{\circ}C$ 이하로 조절하였으며, Borax의 적정 함량은 3.0wt%였다. 2. SCD에 Carbopol을 0.0~3.0wt% 첨가하여 상분리량을 70.0%에서 0.0%로 조절하였으며, Carbopol의 적정 함량은 1.5wt%였다.3. 축열재 내구성 검증을 위하여 0~1,500회의 상변화 사이클을 수행하였다. 이때 상변화 온도의 변화량이 $\pm$1.$0^{\circ}C$ 이하, 잠열량 변화가 $\pm$2.0 kacl/kg 이하로서 안정된 값을 보였다. 이상의 결과로 볼 때 축열재의 수명을 10년까지는 보장할 수 있는 것으로 판단되었다.

• 한국연소학회:학술대회논문집
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• 2004.06a
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• pp.242-247
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• 2004

An Experimental study was conducted on spray combustion using dual swirlers at different outlet angle; co-swirl and counter-swirl. To understand the characteristics of turbulent spray combustion of dual swirl flow (DSF), the axial helical annular vaned swirlers with various swirl ratios and combination of angle and direction were designed. and temperature measurements of a rapidly thermocouple insertion and measurements of soot volume fraction and microrstructure using thermophoretic sampling particle diagnostic (TSPD) as TEM were carried out. The NOx, $CO_2$, $O_2$, etc. was analyzed using emission gas analyzer. The results show that flame stability were maintained under very lean condition. for both co-swirl and counter-swirl case. And though Counter-swirl case kept the higher temperature region compared to co-swirl case, Counter-swirl combustion represented less NOx emission and soot formation than co-swirl case.

• Journal of the Korean Ceramic Society
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• v.36 no.5
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• pp.497-503
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• 1999

Recently regenerative burner system was developed and begins to be gradually used for better energy savings. Compared to conventional burner system the regenrative one has the several merits such as higher fuel efficiency light weigh of apparatus low harmful toxic gas and homogeneous heating zone etc. The regenerative material a very important component of the new regenerative burner system should possess the properties of low specific density higher surface area and high specific heat capacity. Ceramics is the best regenerative material because of stable mechanical properties even at high temperature and better thermal properties and excellent chemical stability. In this study alumina ball alumina tube 3-D ceramic foam and hoeycomb as regenerative materials were tested and evaluated. The computer silumation was conducted and compared to the result of field test. This paper is aimed to introduce a new application of ceramics at high temperature.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.584-587
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• 2011

An internal flow aerodynamic test was performed for a Mach 5 scramjet engine. The test was done without fuel injection, as a preliminary test for the combustion test. Test engine is an engineering model with intake cross-section of $70mm{\times}200mm$ and total length of 1.7m. Test facility is a blowdown-type, high enthalpy, hypersonic facility. 19 pressures were measured through the holes on the model surface along the engine internal flow passage. It was found that the facility start is possible, and also supersonic flow is maintained inside the engine.