• Proceedings of the SAREK Conference
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• 2007.11a
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• pp.540-545
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• 2007

The performance of microturbine CHP system equipped with an absorption chiller was analyzed by modelling of a microturbine and an absorption chiller. The microturbine having recuperator was simulated by the Brayton cycle model. The mass flow rate and available heat energy of the exhaust gas from the microtubune were simulated, and this results were utilized as input values for the generator of the absorption chiller. The absorption chiller is a single-effect air cooled type having solution heat exchanger. When heat input to the generator increased, the heat transfer rate and UA of the heat exchangers of the absorption chiller proportionally increased. Besides, the COP of the absorption chiller increased with increase of the heat input to the generator under the sufficient size of the evaporator condition. When the capacity of the CHP system increased from 30 to 60 kW, the mass flow rate of the LiBr for the absorption chiller increased by two times, and UA values for evaporator and condenser were increased by 3.9 and 3.4 times, respectively, under the same COP condition.

• 유체기계공업학회:학술대회논문집
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• 2002.12a
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• pp.307-313
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• 2002

In the paper, the prototype development of a 75kW class microturbine for the distributed generation market is partly presented which has continued with the government funding. In the introduction, an overview of the development of microturbines in the world is presented. A series of development procedures are shown with design, manufacture and self-sustaining tests. During the first year, aerodynamic and structural design/analysis, mechanical design are performed for the compressor, the turbine and the combustor. A premixed lean burn combustor technology is used fur the low emission requirements. Foil air bearings and high-speed motors are employed for higher reliability. The self-sustaining conditions have been successfully achieved with the prototype manufactured engine as a preceding operation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.1
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• pp.42-48
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• 2009

Microgrid supplies loads with power interconnected grid. And it is defined a independent power system compounded micro sources over two devices which have enough capacity to operate independently, storage devices and loads. The energy sources of micro source have different dynamic characteristics corresponding to classes and application skills. However their transient responses are various from a few seconds to minutes. Therefore it is limitation for understanding operation characteristics of microsource modeling constant voltage source or constant current source. This paper shows that we designed EMTP/RV model of micro source which is microturbine based energy source. And we performed dynamic analysis of micro source corresponding to operation mode of microgrid.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1170-1171
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• 2008

Microsources supply high quality power from 1kW to a matter of MW with higher reliability and energy efficiency than the existing large power facilities. In this paper, we designed dynamic modeling of Microturbine and Fuel cell being worthy as a small distributed energy source. Using EMTP we designed the dynamic modeling and confirmed characteristics of steady-state and dynamic analysis. In this paper, we designed dynamic modeling of Microturbine and Fuel cell being worthy as a small distributed energy source and analyzed dynamic characteristics corresponding to load variation.

• JOURNAL OF ELECTRICAL WORLD
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• s.335
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• pp.22-27
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• 2004

Microturbine geneator is the system generating electric power under 300kW using a gas turbine, and the combined heat and power generating system is recycling exhausted gas to increase thermal efficiency. Microturbine system is featured as small, efficient

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.12
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• pp.1249-1255
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• 2006

This paper presents a constant power control logic for perfect starting a microtubine in vehicle. Under extremely low temperature, performance of the start-up system is severely dropped than that of room temperature because of increasing of load of mechanical parts including engine core and drop of the lead-acid battery capacity. Unfortunately, performance drop of lead-acid battery makes severe problems that cause a malfunction of fuel and lubrication system and power fail of digital devices. So we propose the new start-up logic by constant output power control of lead-acid battery using PWM inverter controller for preventing above problems and keeping good performance of start-up system for microturbine. Also, we prove usefulness of new start-up logic through experimental results under $-32^{\circ}C$ ambient temperature.

• The KSFM Journal of Fluid Machinery
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• v.12 no.2
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• pp.46-51
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• 2009

Recently, microturbines have received attention as a small-scale distributed power generator. Since the exhaust gas carries all of the heat release, generating hot water is usual method of heat recovery from microturbine CHP (combined heat and power) systems. The power of microturbines decreases as ambient temperature increases. This study predicted micoturbine power boost by injecting hot water generated by heat recovery. Influence of injecting water at two different locations was examined. Water injection improves power, but efficiency depends much on the injection location. Injecting water at the compressor discharge shows a much higher efficiency than the combustor injection. However, the combustor injection may have as much available cogeneration heat as the dry operation, while the available heat in the compressor discharge injection is much smaller than the dry operation.

• 유체기계공업학회:학술대회논문집
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• 2003.12a
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• pp.63-72
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• 2003

In order to reduce NOx emissions in the 20kW class microturbine under development, the low NOx characteristics, as being an application to the lean premixed combustion technology, have been investigated. The study has been conducted at the conditions of high temperature and high pressure. Theair from a compressor with the pressure of 2.5bar, 3.0bar, 3.5bar was supplied to the combustor with the temperature 560K through the air preheat-treatment. The sampling exhaust gas was measured at the immediate exit of the combustor. For the effect of temperature on NO and CO emissions, though NOx were increased, CO was decreased with increasing inlet air temperature. With increasing inlet air pressure, NOx were increased and CO was decreased also. NOx were decreased, but CO was increased with increasing inlet air mass flow rate. The test has been performed on the equivalent ratio of 0.10 to 0.16 in the lean region. NOx were increased with increasing equivalent ratio, but CO was decreased as an influence of flame temperature. CFD work with an appropriate combustion model predicated a complicated swirling flow pattern in the combustor, and also produced a numerical value of NOx and CO emissions which was to be compared with the experimental one. As the results of this study, NOx are expected to be reduced to less than 42ppm at 15% O2 when operated at the design condition of the 20kW class microturbine.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.243-247
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• 2005

This paper describes an on-going national R&D program for the development of a gas turbine/fuel cell hybrid power generation system and related R&D activities. The final goal of this program is to develop a 200kW-c1ass gas turbine/fuel cell hybrid power generation system and achieve high efficiency over $60\%$ (AC/LHV). In the first phase of the development, a sub-scaled 60kW-class hybrid system based on the 50kW-class microturbine and the 5kW SOFC will be developed for the purpose of concept proof of the hybrid system. Core components such as the microturbine and the SOFC system are being developed and parallel preparation for system integration is being carried out. Before the core components are assembled in the final system. operating characteristics of a hybrid system are investigated from a simulated system where a turbocharger (microturbine simulator) and a modified fuel cell burner test facility (fuel cell simulator) are employed. The 60kW demonstration unit will be built up and operated to provide the valuable information for the preparation of the final full scale 200kW hybrid system.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.7
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• pp.57-66
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• 2009

Microturbines system (MTS) are currently being deployed as small scale on-site distributed generators for microgrids and smart grids. In order to fully exploit DG potentialities, advanced integrated controls that include power electronics facilities, communication technologies and advanced modeling are required. Significant expectations are posed on gas microturbines that can be easily installed in large commercial and public buildings. Modeling, control, simulation of microturbine generator based distributed generation system in smart grid application of buildings for both grid-connected and islanding conditions are presented. It also incorporates modeling and simulation of MT with a speed control system of the MT-permanent magnet synchronous generator to keep the speed constant with load variation. Model and simulations are performed using MATLAB, Simulink and SimPowerSystem software package. The model is built from the dynamics of each part with their interconnections. This simplified model is a useful tool for studying the various operational aspects of MT and is also applicable with building cooling, heating and power (BCHP) systems