• Proceedings of the KSME Conference
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• 2007.05b
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• pp.3224-3229
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• 2007

This study aims to analyse the influence of steam injection on the performance of hybrid systems combining a solid oxide fuel cell and a gas turbine. The steam is generated by recovering heat from the exhaust gas. Two system configurations, with difference being the operating pressure of the SOFC, are examined and effects of steam injection on performances of the two systems are compared. Two representative gas turbine pressure ratios are simulated and a wide range of both the fuel cell temperature and the turbine inlet temperature is examined. Without steam injection, the pressurized system generally exhibits better system efficiency than the ambient pressure system. Steam injection increases system power capacity for all design cases. However, its effect on system efficiency varies much depending on design conditions. The pressurized system hardly takes advantage of the steam injection in terms of the system efficiency. On the other hand, steam injection contributes to the efficiency improvement of the ambient pressure system in some design conditions. A higher pressure ratio provides a better chance of efficiency increase due to steam injection.

• Design & Manufacturing
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• v.9 no.2
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• pp.10-15
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• 2015

The water has been the suitable for the cooling medium until now. But the water as cooling medium seem to have the limit for high speed injection. The steam plastic molding injection use the steam as the medium when raise the mold temperature. The weld line has been the major quality problems in a plastic injection parts to be difficult to be solved. These problems in injection-molded plastic parts are difficult to find the reason because these issues are usually in tradeoff realtions with each other. The purpose of this paper is to obtain the optimum injection moulding condition for improving the quality of plastic injection parts and to inquire the productivity improvement with the measured cycle time by steam plastic moluding injection. Based on these numerical results, the guidelines of mould design and injection processing condition were established. As a result, the improvement of quality and the reduction of cycle time was achieved.

• The KSFM Journal of Fluid Machinery
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• v.14 no.6
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• pp.68-75
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• 2011

This study simulated the effect of steam injection on the performance and operation of a gas turbine combined heat and power (CHP) system. A commercial simple cycle gas turbine was analyzed. A full off-design analysis was carried out to investigate the variations in not only engine performance but also the operating characteristics of the compressor caused by steam injection. Variation in engine performance and operation characteristics according to various operation modes were examined. First, the impact of full steam injection was investigated. Then, operations aiming to guarantee a minimum compressor surge margin, such as under-firing and partial steam injection, were investigated. The former and latter were turned out to be relatively superior to each other in terms of power and efficiency, respectively.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.8
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• pp.996-1008
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• 1997

This paper describes a methodology and results for the analysis of a small steam injected gas turbine cogeneration system. A performance analysis program for the gas turbine engine is utilized with modifications required for the model of steam injection and the heat recovery steam generator (HRSG). The object of simulation is a simple cycle gas turbine engine under development which adopts a centrifugal compressor. The analysis is based on the off-design operation of the gas turbine and the compressor performance map is utilized. Analyses are carried out with the injection ratio as the main parameter. The effect of steam injection on the power and efficiency of gas turbine and cogeneration capacity is investigated. Also presented is the variation in the main operating parameters inside the HRSG. Remarkable reduction in NOx generation by steam injection is confirmed. In addition, it is observed that for the 100% power operation the temperature of the cooled first nozzle blade decreases by 100.deg. C at full steam injection, which seems to have a favorable effect on the engine life time.

• Journal of the Korean Wood Science and Technology
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• v.30 no.2
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• pp.158-164
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• 2002

The properties of new porous carbon materials "Woodceramics" are affected by the characteristics of raw boards. To investigate of density profile and resin contents in impregnated boards, control board and 3 types of steam-injected boards were made by steam injection time, The wood species used for manufacturing boards was Sugi(Cryptomeria japonica). The results are as follows: 1) The density gradient of board after 10 minutes steam injection was the smallest and non-steamed board was largest. 2) The resin content and dimensional rise decreased with increase of board density, and were the largest in board after 10minutes steam injection but there was little difference between boards after 5 and 10 minutes steam injection.

• Journal of Hydrogen and New Energy
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• v.28 no.5
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• pp.570-576
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• 2017

Gas turbine system with steam injection has shown outstanding advantages such as high specific power and NOx reduction. In the present work, a comparative exergetic analysis was carried out for Steam Injected Gas Turbine (STIG), Regenerative Steam Injected Gas Turbine (RSTIG), and Regenerative After Fogging Gas Turbine (RAF). Effects of pressure ratio, steam injection ratio and steam injection method on the system performance was theoretically investigated. The results showed that the order of the highest exergy efficiency is RSTIG, RAF, and STIG for low pressure ratios but STIG, RSTIG, and RAF for high pressure ratios. In each arrangement, the combustion chamber has the highest exergy destruction and the compressor has the second one.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.6
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• pp.877-885
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• 2008

Steam injection heater is the most widely used method for fresh water generator throughout industry. This method is often chosen because of its simplicity. The steam bubbles condense and give up their heat to the surrounding liquid. Experimental study on steam injection heater has been performed in order to find the effect of major parameter. And conservation equation and Bernoulli obstruction theory are used for numerical simulation model of vapor flow-rate. Qualitative comparisons between simulations and measurements show a good agreement and the simulation models are thereby verified.

• Nuclear Engineering and Technology
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• v.56 no.3
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• pp.1052-1065
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• 2024

Advanced Pressurized Water Reactors (APWRs) and Boiling Water Reactors (BWRs) employ a suppression pool as a heat sink to prevent containment overpressure. Steam can be discharged into the pool through multi-hole spargers or blowdown pipes in both normal and accident conditions. Direct Contact Condensation (DCC) creates sources of momentum and heat. The competition between these two sources determines the development of thermal stratification or mixing of the pool. Thermal stratification is of safety concern as it reduces the cooling capability compared to a completely mixed pool condition. In this work we develop a scaling approach to prediction of the thermal stratification in a water pool induced by steam injection through spargers. Experimental data obtained from large-scale pool tests conducted in the PPOOLEX and PANDA facilities, as well as simulation results obtained using validated codes are used to develop the scaling. Two injection orientations, namely radial injection through multi-hole Sparger Head (SH) and vertical injection through Load Reduction Ring (LRR), are considered. We show that the erosion rate of the cold layer can be estimated using the Richardson number. In this work, scaling laws are proposed to estimate both the (i) transient erosion velocity and (ii) the stable position of the thermocline. These scaling laws are then implemented into a 1D model to simulate the thermal behavior of the pool during steam injection through the sparger.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.1
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• pp.77-86
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• 1992

This paper discusses the thermodynamic study on the suction cooling-steam injected gas turbine cycle. The aim of this study is to improve the thermal efficiency and the specific output by steam injection produced by the waste heat from the waste heat recovery boiler and by cooling compressor inlet air by an ammonia absorption-type suction cooling system. The operating region of this newly devised cycle depends upon the pinch point limit and the outlet temperature of refrigerator. The higher steam injection ratio and the lower the evaporating temperature of refrigerant allow the higher thermal efficiency and the specific output. The optimum pressure ratios and the steam injection ratios for the maximum thermal efficiency and the specific output can be found. It is evident that this cycle considered as one of the most effective methods which can obtain the higher thermal efficiency and the specific output comparing with the conventional simple cycle and steam injected gas turbine cycle.

• Journal of the Korean Society of Propulsion Engineers
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• v.14 no.1
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• pp.29-39
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• 2010

The system performance of the regenerative gas-turbine cycle with the steam injection into the combustor has been studied through the thermodynamic cyclic analysis. The effects of the pressure ratio, the steam injection ratio, the ambient temperature, and the turbine inlet temperature are investigated on the thermal efficiency, the fuel consumption, and the specific power as well as the operating conditions for the maximum thermal efficiency of the system. The results of the present analysis find that the use of steam injection in the regenerative gas-turbine system can greatly enhance the thermal efficiency and the specific power of the system.