• Journal of the Korean Society of Propulsion Engineers
• /
• v.13 no.3
• /
• pp.20-26
• /
• 2009

Turbopump test for a 30-ton-thrust liquid rocket engine was carried out using real-propellant. Liquid oxygen, kerosene, cold hydrogen gas were used for the oxidizer pump, the fuel pump, and the turbine, respectively. The turbopump was reliably operated at the design and off-design conditions and the performance requirements were satisfied, which implies that the turbopump development at the engine subsystem level is successfully accomplished in the point of performance validation. This paper presents the results of a test where the turbopump was run for 75 seconds at three operating modes. In terms of performance characteristics of pumps and turbine, the results of turbopump assembly test using real-propellant showed a good agreement with those of the turbopump component tests using simulant working fluid.

• Design & Manufacturing
• /
• v.12 no.2
• /
• pp.34-39
• /
• 2018

The biggest topics in the automobile industry are light weightening and fuel efficiency improvement. There's a lot of research going on. It is focused on light weight materials. Light weight material is seen as the best way to reduce fuel consumption and to solve the problem of environmental pollution and resource depletion. For the light weight materials, new materials such as aluminum, magnesium, and carbon-hardening materials can be found. Research on the joining techniques of dual materials, improvement of material properties by improving the method of manufacture of existing materials, and studies on ultra-high strength steel sheets are expected to take up the most weight in lightweight materials. As the strength of the ultra-high strength steel sheets increases during forming, it is difficult to obtain dimensional precision due to the increase in elastic restoring force compared to mild or high strength steel sheets. Spring back is known to be affected by a number of factors due to poor plastic molding, and can be divided into the effects of the material spraying and the process. The study on the plasticitic variables were studied as plasticitic factors that can be controlled by a part company. Tensile testing of ultra-high strength materials was conducted to derive properties for plasticitic analysis and to analyze spring back with two factors controlling the height of the bead and blank holding force by adding tensile force and controlling the flow rate.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2008.11a
• /
• pp.359-365
• /
• 2008

Turbopump test for a 30-ton-thrust liquid rocket engine was carried out using real-propellant. Liquid oxygen, kerosene, cold hydrogen gas were used for the oxidizer pump, the fuel pump, the turbine, respectively. The turbopump was run stably at the design and off-design conditions and the performance requirements were satisfied, which implies that the turbopump development at the engine subsystem level is successfully accomplished in the point of performance validation. This paper presents the results of a test where the turbopump was run for 75 seconds at three operating modes. In terms of performance characteristics of pumps and turbine, the results from turbopump assembly test using real-propellant showed a good agreement with those from the turbopump component tests using simulant working fluid.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.35 no.10
• /
• pp.1033-1040
• /
• 2011

The premixed burner is a very strong candidate for using household boiler burner system because it has high efficiency, low emission and can be used in compact boiler system. Usually, household boiler burner systems use a Bunsen burner, which consists of an inner rich premixed flame and fuel burned completely by a secondary air supply. It has a relatively long flame length and operates in a high excess of air, so it is difficult to fit such a burner into a high efficiency compact boiler. In this paper, the characteristics of a premixed combustion burner for surface media such as metal fiber, ceramic, and SUS fin were evaluated. In particular, the flow velocity over the burner surface for the cold flow characteristics of the surface material were measured and adjusted. The combustion tests were carried out by taking pictures of the flame and measuring the flame temperature. The amounts of CO and NO were measured and the characteristics of the surface burner materials, combustion chamber, and heat exchangers were evaluated for various excess air ratios and heating values.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.27 no.1
• /
• pp.135-144
• /
• 2021

In this study, we investigated the characteristics of the process of hydrogen production using boil-of gas (BOG) generated from an LNG-fueled ship and the application of hydrogen fuel cell systems as auxiliary engines. In this study, the BOG steam reformer process was designed using the UniSim R410 program, and the reformer outlet temperature, pressure, and the fraction and consumption of the product according to the steam/carbon ratio (SCR) were calculated. According to the study, the conversion rate of methane was 100 % when the temperature of the reformer was 890 ℃, and maximum hydrogen production was observed. In addition, the lower the pressure, the higher is the reaction activity. However, higher temperatures have led to a decrease in hydrogen production owing to the preponderance of adverse reactions and increased amounts of water and carbon dioxide. As SCR increased, hydrogen production increased, but the required energy consumption also increased proportionally. Although the hydrogen fraction was the highest when the SCR was 1.8, it was confirmed that the optimal operation range was for SCR to operate at 3 to prevent cocking. In addition, the lower the pressure, the higher is the amount of carbon dioxide generated. Furthermore, 42.5 % of the LNG cold energy based on carbon dioxide generation was required for cooling and liquefaction.

• Proceedings of the KIEE Conference
• /
• 1995.07c
• /
• pp.1051-1053
• /
• 1995

Nowadays perovskite $La_{1-x}Sr_xMnO_3$ is preferred cathode material in Solid Oxide Fuel cell(SOFC). The $La_{1-x}Sr_xMnO_3$ with Sr contents ranging $x=0{\sim}1.0$ were prepared by a citrate method. These powders were characterized by usual means like TG/DTA, X-ray diffraction analysis. The samples used for measuring thermal expansion were prepared as pellets by cold pressing and subsequent sintering in air at $1200^{\circ}C$ for 5 hours. To measure the by-product of $La_{1-x}Sr_xMnO_3$ reacted with 8mol% YSZ, that samples were sintered at $1200^{\circ}C$ for 5 hours.

• New & Renewable Energy
• /
• v.9 no.4
• /
• pp.32-39
• /
• 2013

A 2-loop waste heat recovery system with Rankine steam cycles for the improvement of fuel efficiency of gasoline vehicles has been investigated. A high temperature loop is used to recover waste heat from exhaust gas and a low temperature loop is used to recover waste heat from cold engine coolant. This paper has dealt with a layout of low temperature loop system, the review of the velocity contours through numerical analysis. According to the result of analysis, the designed heat exchanger. And comparing with flow analysis results, LT Boiler is safe to operation.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.2 no.3
• /
• pp.175-180
• /
• 2004

In order to vitrify the combustible dry active waste (DAW) generated from Korean Nuclear Power Plants, a glass formulation development based on waste composition was performed. A borosilicate glass, DG-2, was formulated to vitrify the DAW in an induction cold crucible melter (CCM). The processability, product performance, and volume reduction effect of the candidate glass were evaluated using a computer code and were measured experimentally in the laboratory and CCM. The glass viscosity and electrical conductivity as the process parameters were in the desired ranges. Start-up and maintaining glass melt of the candidate glass were favorable in the CCM. The product of the glass product such as chemical durability, phase stability, and density was satisfactory. The vitrification process using the candidate glass was also evaluated assuming that it was operated as economically as possible.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
• /
• v.8 no.2
• /
• pp.27-35
• /
• 2012

Five zero energy house models developed in Korea for the purpose of the energy performance were compared and analyzed in the study. The standard passive house model applying common technology and efficient energy performance elements was proposed. Standard passive house 5 models have been developed commonly aiming at 100% energy saving, applying high-performance and high-efficiency exterior thermal insulation, using 3 low-e coated window system, and targeting average 0.65 ACH to enhance privacy. Energy recovery ventilators and dry and cold radiant heating floor has been partially applied. Eco-design techniques such as the awning device, heat insulating door, using natural light have been used. Solar and geothermal systems as the application of renewable energy technologies have been commonly applied. And fuel cells were applied to a partial model. The standard model based on common technical elements and average performance of each element and obtained from five model analysis has been proposed in the study.

• Proceedings of the KIEE Conference
• /
• 1994.11a
• /
• pp.202-204
• /
• 1994

Nowadays Perovskite $La_{1-x}Sr_xCoO_3$ is a preferred cathode material in the construction Solid Oxide Fuel Cell (SOFC). The $La_{1-x}Sr_xCoO_3$ with Sr contents ranging from X=0.0 to X=1.0 were prepared by a citrate method. All samples were examined by X-ray powder diffraction. The samples used for measuring thermal expansion were prepared as pellets by cold pressing and subsequent sintering in air at $1200^{\circ}C$ for 5 hours. To measure the sub-product of $La_{1-x}Sr_xCoO_3$ with YSZ, where coating films were sintered at $1200^{\circ}C$ for 5 hour.