• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
• /
• 2003.05a
• /
• pp.198-202
• /
• 2003

A small circulating water channel (CWC) for experiments ocean engineering is designed and made through the co-work of a company, MESTEC, and a college, Inha Technical Research Institute. General function of the elements of CWC are explained. The velocities in the test section are measured and analysed to estimate the performance of the CWC. The result of the velocity distribution is acceptable for experiments of ocean engineering.

• Analytical Science and Technology
• /
• v.13 no.1
• /
• pp.5-11
• /
• 2000

During the commissioning period in Tonghae thermal power plant which is the largest circulating fluidized bed boiler in the nation, a considerable amount of clinker was formed at FBAC and seal pot. Various attempts, for example, concentration analysis, surface phenomena, thermal characterization, and crystal structure of ash, bed sand, limestone, clinker, and mixture of each gradients have been studied to identify the causes of clinker formed in circulating fluidized bed boiler. As the results, the characterization of black particles in which separated from the clinker is more similar to that of bed sand, on the other hand, white particles are more similar to ash. In addition, the sintering temperature of sand is over $1,200^{\circ}C$ and this temperature was decreased as limestone is added to bed material. The cause of clinker was proved that ash was sticked to molten or sintered sand or limestone in the area of high temperature in the circulating system.

• Journal of Ocean Engineering and Technology
• /
• v.13 no.1 s.31
• /
• pp.105-112
• /
• 1999

This research is an experimental investigation of the region of the Biased Flow. This experiment was carried out in a circulating water channel, and the results are analyzed by using the PIV technique. The results are presented in velocity vector field, velocity contour and vorticity contour. The results were compared with those of Zdravkovich which were carried out in a wind tunnel. These results will be very useful to verify numerical codes.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.13 no.2
• /
• pp.109-121
• /
• 2001

This paper describes results of an experimental study to examine the effect of a submerged horizontal breakwater to sea water exchange. Flow measurements were taken by using a PIV(Particie Image Velocimetry) system, and mean currents and wave ellipses extracted through the harmonic analysis are presented. As results, the rates of circulating flow were closely connected with the volume flux of incident waves and the counter-rotating vortex pair was observed at the onshore side of a plate. The dye study showed that incoming sea water and polluted water body mixed up significantly due to turbulent motions induced by a jet-like flow.

• Journal of Institute of Control, Robotics and Systems
• /
• v.3 no.2
• /
• pp.162-168
• /
• 1997

Digital variable structure controller(DVSC) is implemented to control the temperature for the hot water heating circulating pump control system. For the DVSC, a control algorithm is suggested, which using a nonlinear sliding surface and a PID sliding surface outside and inside of steady state error boundary layer, respectively. Smith predictor algorithm is used for the compensation of long dead time. The DVSC of the suggested algorithm yields improved control performance compared with the one of existing algorithm. The system responses with the suggested DVSC shows good responses without overshoot and steady state error inspite of heating load change. By decreasing sampling time, dead time and rise time are increasing, and system output noise by flow dynamics is amplified.

• Journal of the Korean Society of Combustion
• /
• v.7 no.3
• /
• pp.16-22
• /
• 2002

Combustion performance of an internally cycloned circulating fluidized bed for paper sludge was discussed through a series of batch type experiments. Operation parameters such as water content, feeding mass of sludge and secondary air injection rate were varied to find out the effect on the combustion performance, which was examined with carbon conversion rate and pollutant emission such as CO and NOx. A conventional solid fuel reaction was observed in the experiments of varying water content and feeding mass of the sludge, which is characterized with kinetic limited reaction zone, diffusion limited reaction zone and transition zone. Secondary air injection with swirl enhances the mixing of the gas phase as well as the solid phase, and improves combustion efficiency accompanied with higher carbon conversion rate and lower pollutant emission rate.

• 한국연소학회:학술대회논문집
• /
• 2002.06a
• /
• pp.204-211
• /
• 2002

Combustion experiments are carried out to obtain the fundamental data for application of a internally circulating fluidized bed combustor to the combustion of paper sludge wastes. Experimental parameters are identified as secondary air ratio, sludge weight and water contents. The secondary air ratio was varied from 0 to 20% and water content was 14%, 25%, 35%, 45%, 62% and sludge weight was 30g, 60g, 90g. As a result, carbon conversion ratio was higher than injection of primary air. Emission of CO and NOx reduced with an increase of secondary air injection.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.10 no.1
• /
• pp.108-117
• /
• 1998

This study was performed to analyze the fluid flow characteristics and the temperature distribution of the aquarium for fish breeding. In this study, the finite volume method and turbulence k-$\varepsilon$ model with the SIMPLE computational algorithm are used to study the water flow in the aquarium. The calculation parameters are the circulating flow rate and the basin depth, and the experiments were carried out for the water flow visualization This numerical analysis gives reasonable velocity distributions in good agreement with the experimental data. As the results of the three dimmentional simulations, the sectional mean velocity increased as the sectional mean temperature increases for constant basin depth, and the mean velocity increased more rapidly for small basin depth than that of large basin depth, The mean velocity and temperature can be expressed as the function of the circulating flow rates and the basin depth.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2020.06a
• /
• pp.126-127
• /
• 2020

Recently, as interest in environmental issues increases, minimizing carbon dioxide generated during cement manufacturing is a problem to be solved. In order to solve such a problem, it is required to use an industrial by-product of recycled aggregate, blast furnace slag, and circulating fluidized bed boiler fly ash to replace it on the basis of geopolymer(=cementless). This study examines the characteristics of eco-friendly artificial stone according to the mixing ratio of geopolymer-based recycled aggregate. As a result of the experiment, when the addition rate of the alkali stimulant was 15% and the mixing ratio of the circulating aggregate was 70%, the flexural strength and compressive strength were the highest. Density and water absorption decreased as density of circulating aggregates increased and water absorption increased. However, when the mixing ratio of the circulating aggregate exceeded 70%, the flexural strength and compressive strength decreased. Therefore, in order to obtain strengths meeting the KS standards, the mixing ratio of recycled aggregate was set to 70%, and artificial stone was manufactured using industrial by-products.

• Journal of the Korean Solar Energy Society
• /
• v.22 no.2
• /
• pp.11-17
• /
• 2002

This paper is concerned with the development of a new method for making, separating ice and storage floated ice by installing an evaporation plate at under-water within a storage tank. In a conventional harvest-type ice storage system, a tank saves ice by separating an ice from an installed evaporation plate, which is located above an ice storage tank as an ice storage system. Developed new harvest-type method shows good heat transfer efficiency than a convectional method. It is because the evaporation panel is directly contacted with water in a storage tank. Also, at a conventional system a circulating pump, a circulating water distributor and a piping are installed, however these components are not necessary in a new method. In this study ice storage systems are experimentally investigated to study the charge and discharge of thermal energy. The results show the applicable possibility and performance enhancement of a new type.