Hyun Seok Cho

Particles fluidized bed receiver/reactor with a beam-down solar concentrating optics: 30-kWth performance test using a big sun-simulator

A novel concept of particles fluidized bed receiver/reactor with a beam-down solar concentrating optics was performed using a 30-kWth window type receiver by a big sun-simulator. A fluidized bed of quartz sand particles was created by passing air from the bottom distributor of the receiver, and about 30 kWth of high flux visible light from 19 xenon-arc lamps of the sun-simulator was directly irradiated on the top of the fluidized bed in the receiver through a quartz window. The particle bed temperature at the center position of the fluidized bed went up to a temperature range from 1050 to 1200°C by the visible light irradiation with the average heat flux of about 950 kW/m2, depending on the air flow rate. The output air temperature from the receiver reached 1000 - 1060°C.

Particles fluidized bed receiver/reactor tests with quartz sand particles using a 100-kWth beam-down solar concentrating system at Miyazaki

A window-type, solar fluidized bed receiver with quartz sand particles was tested by a 100-kWth novel beam-down solar concentrating system at Miyazaki, Japan. A compound parabolic concentrator (CPC) was placed above the quartz window of the receiver to increase the concentration of the solar fluxes from the beam-down solar concentrating system. The solar tests were performed in the middle of December, 2015. The central bed temperature of the receiver was reached around 960-1100° C. It was found that only 20 Ndm3/min of air flow rate was enough to create the uniform fluidization of the particles at the given temperature range. It was predicted that if the central bed temperature could have been higher than 1100°C if solar receiver test had conducted in other seasons than winter. The next solar campaign of the receiver test will be carried out in October, 2016.A window-type, solar fluidized bed receiver with quartz sand particles was tested by a 100-kWth novel beam-down solar concentrating system at Miyazaki, Japan. A compound parabolic concentrator (CPC) was placed above the quartz window of the receiver to increase the concentration of the solar fluxes from the beam-down solar concentrating system. The solar tests were performed in the middle of December, 2015. The central bed temperature of the receiver was reached around 960-1100° C. It was found that only 20 Ndm3/min of air flow rate was enough to create the uniform fluidization of the particles at the given temperature range. It was predicted that if the central bed temperature could have been higher than 1100°C if solar receiver test had conducted in other seasons than winter. The next solar campaign of the receiver test will be carried out in October, 2016.

Development and experimental study for hydrogen production from the thermochemical two-step water splitting cycles with a CeO2 coated new foam device design using solar furnace system

A solar reactor containing a CeO2-coated reactive foam device for producing hydrogen via a thermochemical two-step water splitting cycle was proposed and experimentally tested. Modeling of the optical properties of the 40 kWth KIER (Korea Institute of Energy Research) solar furnace was performed to design and prepare the optimized foam matrix shape and the new solar reactor. Solar demonstration of the solar reactor was accomplished in the KIER 40 kWth solar furnace and hydrogen was produced successfully during the water decomposition step. The conical shape foam device was suggested and tested the temperature gradients and hydrogen productivity. Finally, five cyclic test was conducted with the conical shape CeO2-coated foam device, the total hydrogen production was 1394.32 Ncm3 during the five cycles and the average hydrogen production per cycle was 278.86 Ncm3.A solar reactor containing a CeO2-coated reactive foam device for producing hydrogen via a thermochemical two-step water splitting cycle was proposed and experimentally tested. Modeling of the optical properties of the 40 kWth KIER (Korea Institute of Energy Research) solar furnace was performed to design and prepare the optimized foam matrix shape and the new solar reactor. Solar demonstration of the solar reactor was accomplished in the KIER 40 kWth solar furnace and hydrogen was produced successfully during the water decomposition step. The conical shape foam device was suggested and tested the temperature gradients and hydrogen productivity. Finally, five cyclic test was conducted with the conical shape CeO2-coated foam device, the total hydrogen production was 1394.32 Ncm3 during the five cycles and the average hydrogen production per cycle was 278.86 Ncm3.