• New & Renewable Energy
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• v.6 no.3
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• pp.22-29
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• 2010

The concept of Ocean Thermal Energy Conversion (OTEC) is simple and various types of OTEC have been proposed and tried. However the location of OTEC is limited because OTEC requires $20^{\circ}C$ of temperature difference as a minimum, so most of OTEC plants were constructed and experimented in tropical oceans. To solve this we proposed the modified OTEC which uses condenser discharged thermal energy of existing fossil or nuclear power plants. We call this system CTEC (Condenser Thermal Energy Conversion) as this system directly uses $32^{\circ}C$ partially saturated steam in condenser instead of $20{\sim}25^{\circ}C$ surface sea water as heat source. Increased temperature difference can improve thermal efficiency of Rankine cycle, but CTEC should be located near existing plant condenser and the length of cold water pipe between CTEC and deep cold sea water also increase. So friction loss also increases. Calculated result shows the change of efficiency, pumping power, net power and other parameters of modeled 7.9 MW CTEC at given condition. The calculated efficiency of CTEC is little larger than that of typical OTEC as expected. By proper location and optimization, CTEC could be considered another competitive renewable energy system.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.10
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• pp.408-413
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• 2016

The objective of this study is to investigate the performance of a heat recovery heat pump dryer using a R245fa refrigerant experimentally. In this study, the main components of the heat pump dryer were an evaporator, a compressor, a condenser, and an expansion valve. As a result, when the amount of refrigerant varied from 15 kg to 16 kg, the hot air outlet temperature in the condenser and the heat transfer rate were almost kept constant. Therefore, the amount of refrigerant at 16 kg was considered to be a suitable amount in the heat pump. As the air inlet velocity varied from 0.5 m/s to 1.5 m/s, the highest temperature in the condenser could be obtained when the air inlet velocity was 0.5 m/s. The heat transfer rate, system (COP), and hot air outlet temperature were 5.6 kW, 3.4, and $102.5^{\circ}C$, respectively, when the bypass ratio and water temperature were 0% and $60^{\circ}C$.

• Journal of Energy Engineering
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• v.29 no.3
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• pp.7-17
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• 2020

Heat recovery steam generator(HRSG) generate steam using the high-temperature exhaust energy of gas turbines. Structures of HRSG are damaged by flow induced vibration of flue gas in some cases. In order to evaluate fatigue life to predict damage to a structure, a vibration analysis caused from flue gas should be used to derive the Power Spectral Density(PSD). However, it is very difficult to experimentally derive the vibrations generated by the exhaust gas form of gas turbines, which is very fast and complex. It was able to establish a way to identify vibration characteristics depending on the location of the structure by using high computing resources, large eddy simulation (LES). Random vibration analysis through these vibration characteristics(PSD) can evaluate the fatigue life of a structure.

• Journal of Power System Engineering
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• v.13 no.6
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• pp.1-6
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• 2009

• 월간 기계설비
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• no.8 s.193
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• pp.70-71
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• 2006

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.38 no.2
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• pp.31-35
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• 2009

• Korean Chemical Engineering Research
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• v.51 no.2
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• pp.245-249
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• 2013

The depropanizing, debutanizing and deisobutanizing fractionation steps of processing natural gas liquids were improved through studying complex distillation arrangements, including the double dividing wall column arrangement (DDWC), the sequence including a dividing wall column (DWC) and a bottom DWC (BDWC), and the sequence including a DWC and a BDWC with top vapor recompression heat pump. These arrangements offer benefits by decreasing reboiler and condenser power consumption. Reducing the number of columns and their diameters can potentially reduce construction costs. The result also showed that operating cost could be reduced most significantly through novel combinations of internal and external heat integration: bottom dividing wall columns employing a top vapor recompression heat pump.

• Journal of computational fluids engineering
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• v.15 no.1
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• pp.17-23
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• 2010

Performance improvements of the heat recovery steam generator(HRSG) can be achieved by improving the flow distribution of exhaust gases for a various type of different equipments. A number of design parameters are systematically investigated and their effects on an index of velocity deviation established. The parameters include the three shape of the transition duct and the wide range of the guide vane angles. The numerical results clearly reveal feature of the flow pattern in the transition duct, velocity deviation and pressure drop at tube bank part.

• The KSFM Journal of Fluid Machinery
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• v.19 no.2
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• pp.43-48
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• 2016

This study proves successes of Energy Service Company (ESCO) business by heat pump performance test. The purpose of ESCO business is recover investment costs through saving energy from installation of energy reduction facility. The most important technology assessment items are heat recovery and generator output. Experimental result shows that increase quality of heat recovery (11.52Gcal/h), while decrease generator output (0.234kw). In its final analysis, the ESCO business is successful according to our data.

• Journal of KSNVE
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• v.9 no.6
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• pp.1116-1122
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• 1999

HRSG, which is one of main components of the combined cycle power plant,is composed of an inlet duct, a main body and casing, an outlet duct and a stack. It is important to design HRSG wihtin the allowable noise limit. For this purpose, it is necessary to analyze and predict the noise reduction and radiation at HRSG. In this paper, the technology for the noise prediction at each part of HRSG has been based on the empirical and field data, and also the HRSG noise prediction program has been developed. In order to verify the developed technology and program a field test is conducted. The results of noise prediction show good agreement with the measured.