• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.161-164
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• 2008

For the development of solar thermal power tower plant from the early 80' to today, various kinds of receiver have been tested and evaluated. Most of 1st generation receiver used water/steam as a working fluid to operate steam turbine and now the first commercial solar power tower PS-10 also makes saturated steam. However, to increase thermal efficiency of storage system and to obtain practical use of solar energy, molten salt system have been used from THEMIS project in France at 1984. The Solar Tres plant of 17 MWe power generation will be constructed in Spain and have plan to operate 24 hours in summer. The air volumetric receiver system can be integrated with combined cycle of gas turbine and HRSG and also with steam turbine easily. Therefore, related researches to develop higher efficient solar power tower plant and to operate with stable are widely performed in the world.

• 한국태양에너지학회:학술대회논문집
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• 2012.03a
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• pp.120-125
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• 2012

Daegu Solar Power Tower Plant of a 200 kW thermal capacity uses an open air receiver. An air receiver is generally based on the volumetric receiver concept with porous ceramic absorbers. Because absorber material is important in the volumetric receiver, ceramic materials with excellent thermal conductivity, high solar absorptivity and good thermal stability have been researched. KIER also developed SiC honeycomb absorber modules and evaluated performance of the modules at the KIER solar furnace. For performance evaluation, we made an open volumetric receiver containing the modules and measured the outlet temperature and the efficiency. It is demonstrated that performance of the KIER absorber is comparable to that of a reference absorber developed by DLR.

• Journal of the Korean Solar Energy Society
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• v.27 no.4
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• pp.121-128
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• 2007

Convective heat loss from solar tower receiver is experimentally investigated in wind tunnel with tilt angles and operating conditions. In order to simulate the receiver, an electric heater, which is made of aluminum (width : 100 mm, height : 100mm) is used and installed in the wind tunnel. The convective heat loss from the receiver is dependent on the direction and the velocity of the wind and the surface temperature of the receiver. The tilt angle and surface temperature of the receiver are varied from 0o (cavity facing straight down) and 90o(cavity aligned horizontally) and from $150^{\circ}C$ to $250^{\circ}C$, respectively. Also, the wind speed is changed from 0 to 4m/s. The convective heat loss is obtained by measuring consumed power to the heater to maintain the desired surface temperature. It is concluded that Nusselt number increases with increasing wind speed for all cases. Especially, it is showed that Nusselt number can be maximized when the tilt angle is 30o.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.157-160
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• 2008

Solar receiver in the solar power tower system has a similarity to a boiler of the thermal power plant in many aspects. However Boiler is operated long time without stopping while solar receiver repeats start and stop every day. The objective of this study is to investigate start-up characteristics of solar receiver. The experimental device was constructed in a bench scale. Basic experimental condition of water/steam was set by 25 bar and $223^{\circ}C$. Initially, the heat was added into risers only, then another experiment with input into drum additionally was done. When the heat flux was valid only risers, it took about 300 minutes until the water temperature in drum reached $223^{\circ}C$. Water temperature of drum was increased by $44^{\circ}C$/hr with 91.14 g/s of water circulation. With additional heat input into drum, 200 minutes was required to reach $223^{\circ}C$. In this case temperature was increased $66^{\circ}C$/hr with 96.5 g/s of water circulation.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.3
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• pp.277-284
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• 2012

In this study, a heat-transfer performance analysis is carried out for a multi-channel volumetric air receiver for a solar power tower. On the basis of a series of reviews regarding the relevant literature, a calculation process is proposed for the prediction of the wall- and air- temperature distributions of a single channel at given geometric and input conditions. Furthermore, a unique mathematical model of the receiver effectiveness is presented through analysis of the temperature profile. The receiver is made of silicon carbide. A total of 225 square straight channels per module are molded to induce the air flow, and each channel has the dimensions of $2mm(W){\times}2mm(H){\times}0.2mm(t){\times}320mm(L)$. The heat-transfer rate, temperature distribution and effectiveness are presented according to the variation of the channel and module number under uniform irradiation and mass flow rate. The available air outlet temperature applied to the solar power tower should be over $700^{\circ}C$. This numerical model was actually used in the design of a 200 kW-level commercial solar air receiver, and the required number of modules satisfying the thermal performance could be obtained for the specified geometric and input conditions.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.3389-3394
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• 2007

Characteristics of heat transfer and pressure drops of fills for solar tower volumetric air receivers are experimentally investigated with the material and the thickness. The volumetric air receiver considered in this paper consists of a ceramic tube and fills are inserted in the ceramic tube. Air is used as the working fluid. Two materials, which are a honeycomb(diameter: 100mm, thickness: 30mm) and laminated mesh(diameter: 100mm, thickness: 1mm), are considered as the fills. In order to investigate the characteristics of heat transfer of fills, this volumetric air receiver is heated by an electric heater and air temperatures in ceramic tube are measured. Also, the radiative shields are installed to measure the only air temperature. In addition, the pressure losses are measured with the thickness of fills while the air goes through the fills inserted in an acrylic tube. The flow becomes turbulent and fully developed in front of the fills. The results show that the heat transfer and pressure drop characteristics of the laminated mesh are superior to those of the honeycomb.

• Journal of the Korean Solar Energy Society
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• v.28 no.2
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• pp.1-9
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• 2008

This paper describes water circulation characteristics of a water/steam receiver at various heat fluxes. The water/steam receiver for a solar tower power system is a natural circulation type. Experimental conditions of water and steam were set at a pressure of 5 bar and temperature of $151.8^{\circ}C$. The experimental device for the water/steam receiver consisted of a steam drum, upper/lower header, riser tubes, and downcomer tube. The experiments were conducted by varying heat fluxes in terms of mass flow rate in each riser tube. However, the total mass flow rate on the riser tubes was fixed at 217.4 g/s. For the uniform heat flux, while the water temperature of the steam drum and upper header were kept at steady state, the temperature of the lower header was fluctuated. For the non-uniform heat flux, while the temperature of the steam drum was kept steady state, the temperature difference increased in the right and left side of the upper header, and the temperature of the lower header was fluctuated.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.676-679
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• 2007

This paper describes an experiment facility to measure the circulation characteristics of a water/steam receiver at various heat fluxes. The natural circulation type receiver was considered in this study. The experiment facility was designed to satisfy circulation balance with an appropriate scale down. As a result, riser tube inner diameter was 7.4 mm and water circulation was 0.319 kg/s. Downcomer tube inner diameter by circulation balance was 9.52 mm and the quality was from 0 to 0.23.

• Proceedings of the SAREK Conference
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• 2007.06a
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• pp.171-171
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• 2007

• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.184-187
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• 2006

The heat transfer characteristics of solar tower receivers are experimentally investigated with receiver shapes. Generally the heat transfer characteristics become different according to the shapes and materials of the volumetric air receiver. In order to study these effects, The experimental apparatus adopting laminated mesh and honeycombs as the volumetric air receiver is proposed. The receiver consists of laminated mesh (diameter; 100mm, thickness; 1mm), honeycombs (diameter; 100mm, thickness; 30 mm) inserted out the heat transfer characteristics of the laminated mesh the air temperatures are obtained by installing 3 thermocouples on each layer, dividing ceramic tube into 4 layers. Also, a radiative shield is installed to measure the only air temperature. The data for laminated mesh and honeycomb thickness of 30, 60, 90mm are obtained. The results show that the temperature of layer 3 is higher than those of layer 2 and layer 1.