• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.258-262
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• 2010

Since MEMS based micro actuators or generating devices showed high efficiency per volume, plenty of research are ongoing. Among them, MEMS based millimeter-scale micro gas turbine is one of the most powerful item for replacing chemical batteries. However, due to MEMS manufacturing technique, it is very difficult that makes wide turbine bearing area. It causes low DN number, so sufficient bearing force is hard to achieve. Thus, the most important issue on micro gas turbine is to design the proper bearing which can keep rotor stable during operation. In order to that, micro-scale gas-lubricated bearing is generally used. In this paper, basic feasibility study of thrust bearing of 10mm diameter turbine is described. Thrust bearing is hydrostatic gas-lubricated type. Numerical simulation is performed with ANSYS CFX 11.0 which is commercial numerical tool. Relationship between bearing inlet pressure and mass flow rate and bearing force is figured while changing bearing gap and number of capillaries. The simulation results will be used for further design of micro gas turbine.

• 한국전산유체공학회:학술대회논문집
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• 2011.05a
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• pp.387-391
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• 2011

Since MEMS based micro actuators or generating devices have high efficiency per volume, plenty of research are ongoing. Among them, MEMS based millimeter-scale micro gas' turbine is one of the most powerful issue for replacing chemical batteries. However, since limiting of MEMS manufacturing technique, it is very difficult that makes wide turbine bearing area. It causes low DN number, so sufficient bearing force is hard to achieve. Thus, the most important issue on micro gas turbine is proper bearing design which can keep rotor stable during operation. In order to that, micro-scale gas-lubricated bearing is generally used. In this paper, basic feasibility study and design of journal bearing for 10mm diameter micro gas turbine is described Journal bearing is hydrostatic gas-lubricated type. Numerical simulation is performed with ANSYS CFX 11.0 which is commercial numerical tool. Repulsive force when there is radial displacement in bearing and returning time is calculated using steady and unsteady cases. Auto re-meshing technic is used for moving mesh unsteady cases which simulate displacement of axis and its movement. The simulation results are used for further design of micro gas turbine, and experiment will be done later.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.05a
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• pp.439-444
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• 2009

This paper gives a basic Energy performance data of micro gas turbine and Renewable Energy(BIPV and Solar Collector System) installed in Hospital Building. The efficiency of. solar collector and BIPV system was 30%, 10% individually, and lower than micro gas turbines. Micro gas turbines are small gas turbines that bum gaseous and liquid fuels to produce a high-energy exhaust gas and to generate the electrical power. Recently the size range for micro gas turbines is form 30 to 500kW and power-only generation or in combined heat and power(CHP) systems. If micro gas turbine was operated only for electric energy, the efficiency was about 30%, but for combined heat and power, the efficiency was about 90%. Finally, installed in large hospital, Micro gas turbine system was operated to CHP mode, was high-efficiency system than Solar collector and BIPV system.

• The KSFM Journal of Fluid Machinery
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• v.18 no.5
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• pp.42-48
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• 2015

To improve the core technology of the micro gas turbine, the performance test facility was developed. This paper is focusing on the explanation of the characteristics of micro gas turbine and its assist devices. Major part of micro gas turbine were radial type of compressor, annular type of combustor, radial type of turbine, thrust foil bearing, radial foil bearing and generator. The assist devices were consist of exhaust duct, inverter, data acquisition system, load bank and test cell. Before building up the test facility, the component test was previously conducted to confirm the component performance. After the test facility was prepared, the motoring test was conducted to investigate the rotor dynamic characteristics of the micro gas turbine. Also, the part load performance test was performed. With a developed micro gas turbine test facility, the improved core technology about the micro gas turbine can be suggested to the related industries.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.587-590
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• 2017

Performance test was conducted by micro gas turbine engine. A small test rig was established for the performance measurement of the micro gas turbine engine. The performance was conducted by the Olympus HP engine. Engine inlet mass flow rate, static thrust, fuel consumption rate, air and gas temperature at the inlet of major components were measured. In the test results, we could well understand about the micro gas turbine engine performance characteristics.

• 유체기계공업학회:학술대회논문집
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• 2005.12a
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• pp.331-337
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• 2005

This study aims at evaluation of component performance of a commercial micro gas turbine by detailed measurements of various system parameters. A test facility to measure performance of a micro gas turbine was set up. Performance parameters such as turbine exit temperature, exhaust gas temperature, engine inlet temperature, compressor discharge pressure and fuel flow rate were measured. Variations in measured data and estimated performance parameters were analyzed. In addition to overall engine performance, component characteristic parameters including the turbine inlet temperature, the compressor efficiency, the turbine efficiency, the recuperator effectiveness were estimated. Behaviors of the estimated characteristic parameters with operating condition change were examined.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1136_1138
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• 2009

This paper gives a basic Energy performance data of micro gas turbine and Renewable Energy(BIPV and Solar Collector System) installed in Hospital Building. The efficiency of solar collector and BIPV system was 30%, 10% individually, and lower than micro gas turbines. Micro gas turbines are small gas turbines that burn gaseous and liquid fuels to produce a high-energy exhaust gas and to generate the electrical power. Recently the size range for micro gas turbines is form 30 to 500kW and power-only generation or in combined heat and power(CHP) systems. If micro gas turbine was operated only for electric energy, the efficiency was about 30%, but for combined heat and power, the efficiency was about 90%. Finally, installed in large hospital, Micro gas turbine system was operated to CHP mode, was high-efficiency system than Solar collector and BIPV system.

• 유체기계공업학회:학술대회논문집
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• 2002.12a
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• pp.314-319
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• 2002

Performance analysis and test of a 50kW micro gas turbine is carried out. The present study was initiated in 1996 by KIMM researchers to develope a 50kW class turbogenerator gas turbine engine for hybrid vehicle propulsion system. but with its low emission and compactness, it seemed that it can also be applied as a source of distributed power generation. In this study, general description of the KIMM's efforts to acquire performance test skills of the self-made 50kW micro gas turbine engine. At present, non-load performance test up to 615000 rpm was accomplished and is expected to make through 80,000 rpm by the end of year. Several revisions in design and manufacture were made during the course of experiments. The resulting outputs is thought to be valuable for the further refinement of the system for eventual commercialization of the product.

• The KSFM Journal of Fluid Machinery
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• v.19 no.1
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• pp.24-30
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• 2016

In this study, a 2W micro-gas turbine engine was designed using micro-electro-mechanical systems (MEMS) technology, and experimental investigations of its potential under actual combustion conditions were performed. A micro-gas turbine (MGT) contains a turbo-charger, combustor, and generator. Compressor and turbine blades, and generator coil were manufactured using MEMS technology. The shaft was supported by a precision computer numerical control (CNC) machined static air bearing, and a permanent magnet was attached to the end of the shaft for generation. A heat transfer analysis found that the cooling effect of the air bearing and compressor was sufficient to cover the combustor's high temperature, which was verified in an actual experiment. The generator performance test showed that it can generate 2W at design rotational speed. Prototype micro-gas turbine generated maximum 1 mW electric power and lasted up to 15 minutes.

• The KSFM Journal of Fluid Machinery
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• v.18 no.4
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• pp.22-29
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• 2015

In this study, an in-house program to predict steady state operation of micro gas turbines is constructed using MATLAB. The program consists of two parts: design and off-design simulations. The program is fully modular in its structure, and performance of each component (compressor, combustor, turbine, recuperative heat exchanger and pipe elements) is calculated in a separate calculation module using mass and energy balances as well as models for off-design characteristics. The off-design modules of compressor and turbine use performance maps, which are program inputs. The off-design operation of a micro gas turbine under development was predicted by the program. The prediction results were compared with those by commercial software, and the validity of the in-house program was confirmed.