• Journal of Energy Engineering
• /
• v.24 no.3
• /
• pp.82-88
• /
• 2015

After a reheating furnace installation, the modification of the size and the heat capacity is very difficult. Therefore, the development of design package tool is required for the computation on the correct specifications before the design and the installation. Prior to development of the design tool, a module that calculates the amount of heat loss of each part according to the specifications for determining the thermal efficiency of a continuous heating furnace was developed and applied to the oxy-fuel industrial furnace. Through this, the effects of fuel type, oxygen fraction and recirculation on the efficiency of the furnace of which the output is 110Ton/hour were analyzed. In oxy-fuel combustion condition, the efficiency was 15% higher than air combustion conditions. With the using COG(Coke Oven Gas) instead of LNG, the efficiency was slightly increased. In the air combustion condition, the efficiency was increased about 33% with the preheated air. But, in oxy-fuel condition, the amount of exhaust gas was reduced, so the efficiency was increased about 7%.

• The KSFM Journal of Fluid Machinery
• /
• v.14 no.2
• /
• pp.41-46
• /
• 2011

This study investigated the changes in performance and operating characteristics of an F-class gas turbine according to the change of working fluid from air to carbon dioxide. The revised gas turbine is the topping cycle of the semi-closed oxy-fuel combustion combined cycle. With the same turbine inlet temperature, the $CO_2$ gas turbine is expected to produce about 85% more power. The main contributor is the greater compressor mass flow and the added oxygen flow for the combustion. Compressor pressure ratio increases about 50%. However, the gas turbine efficiency reduces about 10 %. Modulation of inlet guide vane to reduce the compressor inlet mass flow, the major purpose of which is to reduce the compressor inlet Mach number, was also performed.

• Proceedings of the KSME Conference
• /
• 2003.11a
• /
• pp.574-579
• /
• 2003

The present study addresses an analytical investigation to understand the characteristics of gas flow in the High-Velocity Oxy-Fuel(HVOF) thermal spray gun. One-dimensional analysis is extended to involve the effects of the wall friction and powder particle diameter. From the present analysis it is well known that the flow characteristics inside and outside the thermal spray gun is varied depending on the combustion chamber pressure. The thermal spray gun flow is characterized by six different patterns. The powder particle size and wall friction significantly influence the powder particle velocity. The particle velocity decreases with an increase in the powder particle size. This implies that the combustion chamber pressure should be increased to achieve a higher velocity of the powder particle.

• Korean Journal of Materials Research
• /
• v.14 no.2
• /
• pp.110-114
• /
• 2004

High velocity oxy-fuel sprayed NiCoCrAlY coatings were oxidized between 1000 and $1200^{\circ}C$ in air, and the oxide scales were examined by XRD, SEM/EDS, and EPMA. The unoxidized coatings consisted mainly of ${\gamma}$'$-Ni_3$Al, with some ${\gamma}$-Ni. The major oxide formed on the coatings was $\alpha$ $-Al_2$$O_3$. Additionally, (CoCr$_2$$O_4$, $CoAl_2$$O_4$) spinels and $Al_{5}$ $Y_3$$O_{12}$ coexisted. NiO was not found, despite of high amount of Ni in the coating. Below the oxide layer, internally formed $Al_2$$O_3$ existed.

• Transactions of the KSME C: Technology and Education
• /
• v.3 no.4
• /
• pp.285-290
• /
• 2015

Oxy gasification was performed for the production of high quality syngas from the waste. $CO_2$ was used as reactant with $O_2$ for $CO_2$ gasification and greenhouse gas reduction. Therefore, gasification was performed at high temperature of $1000-1400^{\circ}C$. RPF was gasified in the thermobalance and 0.5 ton/day pilot plant gasifier. Weight variation with temperature and CO production by Boudouard reaction were studied for $CO_2$ gasification of RPF in thermobalance reactor. Syngas of high $H_2$ concentration was produced from oxy gasification in 0.5 ton/day pilot system, which showed appropriate $H_2$/CO ratio for the production of transport fuel and chemical products.

• 한국연소학회:학술대회논문집
• /
• 2012.11a
• /
• pp.67-70
• /
• 2012

Many computational fluid dynamic (CFD) simulations have treated the coal kinetics poorly due to large physical domain sizes and high computational complexity, particularly for the recent oxy-coal boilers. Furthermore, some modelers' lack of understanding of the kinetic rate model seems to worsen the simulation accuracy. This study is to suggest the importance of proper use of single-film global kinetic model generally used in CFD code to describe the oxy-fuel combustion of coal char through simple char burnout calculation.

• Korean Chemical Engineering Research
• /
• v.48 no.1
• /
• pp.116-120
• /
• 2010

$CO_2$ is regarded as one of the greenhouse gases(GHG), which is the main reason of climate change. In order to achieve lower $CO_2$ emissions, several efforts have been conducted worldwide. $CO_2$ capture & storage(CCS) technology development is needed for a coal-fired combustion power plant because of huge $CO_2$emission. Oxy fuel combustion, one of the CCS technologies has been considered as a primary concern, nowadays. Oxy-fuel combustion needs flue gas recirculation(FGR) for stable operation and enrichment of $CO_2$ concentration in the flue gas. FGR adoption for oxy-fuel combustion requires development of effective desulfurization and dust removal technology. In this study, desulfurization characteristics of lime and dust removal technology have been researched in the laboratory scale coal combustor.

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

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2011.11a
• /
• pp.258-262
• /
• 2011

The laminar burning velocity in premixed Oxy-CH4 flames was studied in a lab-scale Bunsen burner. $CH^*$ chemiluminescence method and Schliren photography were used. Experimental results were compared with numerical prediction which was calculated with a CHEMKIN 3.7 package with a PREMIX code. Global equivalence ratio of oxy-CH4 mixture was varied from 0.5 to 2.0 in a laminar flow region. The laminar burning velocity was measured as 3.1 m/s for Schlieren photograph and 2.9 m/s for $CH^*$ chemiluminescence technique (angle method).

• Journal of Korean Society for Atmospheric Environment
• /
• v.33 no.5
• /
• pp.473-479
• /
• 2017

This study was designed to understand characteristics of oxy-combustion of coal, dried sewage sludge and solid refuse fuel (SRF). Thermogravimetric analysis was conducted by burning the fuels with air, 21% oxygen ($O_2$)/79% carbon dioxide ($CO_2$) and 30% $O_2/70%$ $CO_2$. Heating rates were varied as 5, 10, 25, 40 and $100^{\circ}C/min$. Complete coal combustion was found at the heating rates of 5, 10, 25 and $40^{\circ}C/min$, and different combustion behavior was found with the gas composition at the heating rates of 10, 25, 40 and $100^{\circ}C/min$. Coal combustion with 30% $O_2/70%$ $CO_2$ showed the highest while coal combustion with 21% $O_2/79%$ $CO_2$ showed the lowest combustion rate. On the other hand, the combustion of dried sewage sludge and SRF showed similar combustion behavior with respect to the combustion gas composition. This suggests that oxy-combustion of dried sewage sludge and SRF which contain a large amount of volatile matter may show similar combustion behavior to their air combustion.