• Journal of computational fluids engineering
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• v.21 no.1
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• pp.19-29
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• 2016

A Prototype Gen-IV Sodium-cooled Fast Reactor which is one of the $4^{th}$ generation nuclear reactors is in development by Korea Atomic Energy Research Institute. The reactor is composed of four main fluid systems which are categorized by its functions, i.e., Primary Heat Transport System, Intermediate Heat Transport System, Decay Heat Removal System and Sodium-Water Reaction Pressure Relief System. The coolant of the reactor is liquid sodium and sodium-to-sodium heat exchangers are installed at the interfaces between two fluid systems, Intermediate Heat Exchangers between the Primary Heat Transport System and the Intermediate Heat Transport System and Decay Heat Exchangers between the Primary Heat Transport System and the Decay Heat Removal System. For the design and performance analysis of the Intermediate Heat Exchanger and the Decay Heat Exchanger, a computer code was written during previous step of research. In this work, the computer code named "SHXSA" has been validated preliminarily by computational fluid dynamics simulations.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.6 no.2
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• pp.166-174
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• 1994

An experimental study has been performed to identify the evaporation characteristics of HCFC-22 for transport refrigeration system. Heat transfer coefficients were measured in a horizontal, smooth evaporating tube with an inner diameter of 10.7mm and a length of 2.8m. The refrigerant was heated electrically by surface-wrapped heaters and uniform power is applied along the tube. The entire tube was divided into 7 sections. Surface temperatures of tube and refrigerant temperature in each test section were measured. Pressure drops in each section and the inlet pressure were also measured. The mass flowrate of the refrigerant was controlled and measured. A single tube evaporation test was conducted for different ranges of mass flux of refrigerant, heat flux of evaporator and condensing temperature of transport refrigeration system. The evaporation heat transfer coefficients of HCFC-22 were compared with predictions from the well known Chen's correlations. Averaged heat transfer coefficients in this experiment range from $2kW/m^2/^{\circ}C$ to $3kW/m^2/^{\circ}C$. Most of the experimental results differ from the predicted ones by less than ${\pm}30%$.

• Journal of the Korean Society for Heat Treatment
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• v.35 no.4
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• pp.193-202
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• 2022

Manholes and underground spaces are installed to manage the buried heat transport pipes of the district heating system, and the corrosion damage of the equipment placed in this space often occurs. The purpose of this work is to identify locations with a high risk of corrosion damage in the air vent and to establish preventive measures based on precise analysis via sampling of heat transport pipes and air vents that have been used for about 30 years. The residual thickness of the air vent decreased significantly by reaching ~1.1 mm in thickness, and locations of 60~70 mm away from a transport pipe were the most vulnerable to corrosion. The energy dispersive X-ray spectroscopy (EDS) analysis was performed in the corroded oxides, and it was found that chloride ion was contained in the corrosion products. Anodic polarization tests were carried out on the air vent materials (SPPS250, SS304) with varying the amounts of chloride ions at two different temperatures (RT, 80℃). The higher concentration of chloride ions and temperature are, the lower corrosion resistances of both alloys are.

• Solar Energy
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• v.12 no.2
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• pp.9-17
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• 1992

This is an experimental work concerning about an application of a heat pipe to an evacuated-glass-tube solar collector system. A methanol heat pipe with length of 0.7 m and diameter of 8 mm was manufactured and tested to compare its performance with that of freon thermosyphon which was originally used in a solar collector system fabricated at Thermomax Co.. Then this methanol heat pipe was utilized to be one component, i.e. heat transfer element, of the present experimental model of a solar collector. This model was performed the operation test as its absorber plate was irradiated by infrared lamps. The following results were obtained. (1) The methanol heat pipe was showed a stable operation when the variation of axial heat transport was $0{\sim}40$ watts and that of inclination angle was $30{\sim}90^{\circ}$. (2) The heat transport capability of the heat pipe was proved to be higher than that of the thermosyphon, because the heat transport limitation of the latter was occured at about 30 watt. (3) The heat pipe in a solar collector was also showed good performance as it transmitted absorbed energy.

• Nuclear Engineering and Technology
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• v.27 no.3
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• pp.358-373
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• 1995

The Heat Transport system loop stability of CANDU-6 reactor using the CANFLEX fuel bundle was studied. The Thermal-hydraulic behavior of CANFLEX fuel bundle is similar to the conventional 37-element fuel bundle since the reactor power and the frictional pressure drop through the fuel channel is almost the same each other, Mounter the CANFLEX fuel bundle gives higher critical channel power and more homogeneous enthalpy distributions in the subchannels than 37-element fuel bundle. The SOPHT modelling or the CANFLEX fuel bundle and the Reactor outlet Header(ROH) interconnection line was made and the stability analysis response of Wolsong-1 reactor with CANFLEX fuel bundle was obtained. Without the ROH interconnection line the Heat Transport system loop using 43-element fuel bundle is unstable like the current 37-element fuel bundle. With the ROH interconnection line, however, the Heat Transport system is stable within $\pm$1％ of nominal flow. In the Heat Transport system loop stability point of view for Wolsong-1 plant therefore, the CANFLEX fuel loading is considered to be acceptable.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1993.11a
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• pp.103-108
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• 1993

In nuclear power plants using pressurized water as the main coolant, it is necessary to maintain system pressure within operational range. During transients, the coolant shrinks and expands causing insurge and outsurge of coolant in the pressurizer. In CANDU system, the pressure is controlled mainly by the pressurizer/degasser-condenser system. In CANDU system, the control of heat transport system pressure is achieved by giving heat to the pressurizer by activating the heaters to compensate a diminution in pressure or by removing heat from the pressurizer by bleeding steam to the degasser-condenser to compensate an increase in pressure. This study aims at developing a theoretical model capable to simulate various operational transients in the CANDU primary heat transport system (PHTS), applicable to CANDU engineering simulator on real time basis.

• Journal of Energy Engineering
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• v.25 no.1
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• pp.15-22
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• 2016

The heat transport system transients of Wolsong 2,3,4 nuclear power plants were analysed during abnormal operating conditions. The compliance with requirements of AECB Regulatory Document R-77 for CANDU reactor was estimated. The analysis results showed that for each postulated accident the peak pressure values in the reactor headers are within the acceptance criteria given in ASME code requirements. The effect of LRV that is one of the overpressure protection device was very minor.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.285-290
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• 2007

KALIMER-600 is a sodium cooled fast reactor with a fast spectrum neutron reactor core. The NSSS design has three heat transport systems of a PHTS (Primary Heat Transport System), a IHTS (Intermediate Heat Transport System) and a SGS (Steam Generation System). PHTS is a pool type and has a large amount of sodium in the pool. The mechanical design targets are maintaining the enough structural integrity for a seismic load of SSE 0.3g and the thermal and mechanical loads by the high temperature environments and an economical competitiveness when compared with other reactor types.

• Fibers and Polymers
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• v.4 no.4
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• pp.215-221
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• 2003

A vertical skin model with two detachable environmental chambers was developed to simulate a Human-Clothing-Environment system and to evaluate heat and moisture transport properties of textile materials under severe conditions and during transient states. The construction of the system was described and data reproducibility and accuracy of the instrument were verified by using PEG treated nonwovens. Also advantages over a traditional static type experiment were demonstrated based on a series of experiments.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.277-281
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• 2008

This paper presents the development of a high efficiency transport refrigeration system for sliced-raw fish transportation. The refrigeration system is equipped with heat storage for reverse cycle-hot gas defrost (the stored heat is used during defrost cycle of the system). System performance and container operating conditions are analyzed during experimental investigation on a $3,225{\times}1,740{\times}1,640\;mm$ full-scale refrigerated container under cooling and defrosting conditions. The prototype system indicates better performance in terms of shorter cooling-down time, shorter defrost time and smaller fluctuations of refrigerated container's temperature.