• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.402-407
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• 2003

The main reason to select the maxium plant efficiency through the performance test in fossil power plant is to increase the efficiency of power plant as well as saving energy collated with the policy of government. This study is aimed at unerstanding the variantion trend of efficiency and analyzing the efficiency of boiler and turbine through each of the performance test. Ultimately, the maxium efficiency of power plant will be presented in super-critical pressure type power plant.

• 한국물환경학회지
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• 제24권4호
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• pp.499-503
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• 2008

In order to control the non-point source pollution, a vegetative filter strips (VFS) was set up and the site-monitoring was performed. The objective of this study is to investigate the influence of the plant coverage on treatment efficiency of total nitrogen (T-N) and total phosphorus (T-P) using vegetative filter strips. According to the results, it seemed that the treatment efficiencies of T-N and T-P were closely related with the plant coverage ratio. The results showed that treatment efficiency of T-P average 50% at higher than 50% of the plant coverage and 20~23% at lower than 50% of the plant coverage. Also, the treatment efficiency of T-N increased with the increase of the plant coverage ratio.

• 신재생에너지
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• 제5권3호
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• pp.32-39
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• 2009

The Samcheonpo ocean small hydropower plant (SHP) has a special feature of using marginal hydraulic head of circulating water system of fossil fuel power plant as a power source and having the characteristics of general hydropower generation and tidal power generation as well. Also, it contributes to reducing green house gases and developing clean energy source by recycling circulating water energy otherwise dissipated into the ocean. The efficiency of small hydropower plant is directly affected by effective head and flow rate of discharged water. Therefore, the efficiency characteristics of ocean hydropower plant are analyzed with the variation of water level and flow rate of discharged water, which is based on the accumulated operation data of the Samcheonpo hydropower plant. After the start of small hydropower plant operation, definite rise of water level was observed. As a result of flow pattern change from free flow to submerged flow, the instability of water surface in overall open channel is increased but it doesn't reach the extent of overflowing channel or having an effect on circulation system. Performance evaluation result shows that the generating power and efficiency of small hydropower exceeds design requirements in all conditions. Analysis results of CWP's water flow rate verify that the amount of flowing water is measured less and the highest efficiency of small hydropower plant is achieved when the effective head has its maximum value. In conclusion, efficiency curve derived from water flow rate considering tidal level shows the best fitting result with design criteria curve and it is verified that overall efficiency of hydropower system is satisfactory.

• Journal of Applied Biological Chemistry
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• 제44권1호
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• pp.16-19
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• 2001

Soybean plants(Glycine max [L.] merr.) inoculated with Bradyrhizobium japonicum MN110 were grown in growth chambers under 400 or $800{\mu}l{\cdot}l^{-1}$ atmospheric $CO_2$ and harvested at 25, 28, 32, and 35 DAT to examine the effect of $CO_2$ enrichment on phosphorus accumulation, uptake, and utilization efficiency during vegetative growth. Phosphorus concentration in leaf was lower in high $CO_2$ plant by 47% at 25 DAT and 34% at 35 DAT than those in the control plant but phosphorus concentrations in stem, root and nodule were not affected by $CO_2$ enrichment. Total phosphorus accumulation increased 3.9-fold in high $CO_2$ plant and 3.2-fold in the control plant between 25 and 35 DAT. Elevated $CO_2$ caused a decrease in the whole plant phosphorus concentration by 35%, which was due almost entirely to a decrease in the phosphorus concentration of leaves. $CO_2$ enrichment increased phosphorus utilization efficiency in the whole plant by 70% during the experimental period. Plants exposed to high $CO_2$ had larger root systems than under ambient $CO_2$, but high $CO_2$ plants had lower P-uptake efficiency. Averaged over four harvests, plants at high $CO_2$ had 38% larger root mass that was more than offset the 20% lower efficiency of P-uptake and accounted for increased phosphorus accumulation by high $CO_2$ plant. These results suggest that the reduced phosphorus concentration in soybean plant under $CO_2$ enrichment may be an acclimation response to high $CO_2$ concentration or enhanced starch accumulation, resulting in the plants to have a lower phosphorus requirement on a unit dry weight basis or a high phosphorus utilization efficiency under these conditions.

• 전기학회논문지
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• 제61권10호
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• pp.1496-1501
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• 2012

A fine tuning on a control system is essential not only for stable operation but also for efficient operation of the power plant. There has been a very few studies on efficiency change by control system tuning. So, it was not clear that if it could be improved or not when the control is stable by fine tuning and how much it could be improved if it works. An accurate algorithm for measurement of the plant efficiency was newly introduced and implemented to measure integrated fuel flow and electricity MW output and to calculate the mean efficiency for given time. As a result, stable operation after fine tuning of control parameters for major controlled variables brought higher efficiency than un-stable operations like a cycling or an oscillation. The plant efficiency has been monitored during various tests and tunings to confirm how much it changes by tuning of the control system on power plant. Now, we can say that the efficiency can be improved in stable operation by fine tuning of the control system.

• Membrane and Water Treatment
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• 제10권1호
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• pp.39-44
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• 2019

LID facilities do not consider environmental factors, and due to inappropriate vegetation planting causing degradation in efficiency due to plant damage and difficulty in maintenance. Therefore, in this study, assessment of impact environmental factor by seasonal variation of chlorophyll and growth of vegetation planted in LID technologies and change of pollutant reduction were conducted. In the case of B-SJ and B-RI, growth rate decreased after summer (August), and B-MG showed steady growth until autumn (September). Chlorophyll was found to increase during spring season while it decreased during autumn season. The chlorophyll concentration was found to affect the plant growth pattern. TN reduction efficiency was highest with greater than 80% efficiency in summer, and it was analyzed that plants were identified as the main factor affecting the seasonal reduction efficiency of TN. Also, temperature and relative humidity were analyzed to affect plant growth, activity and pollutant removal efficiency. Plant type and growth pattern are considered as factors to be considered in selection of appropriate plant types in LID technologies.

• Journal of Biosystems Engineering
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• 제20권1호
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• pp.47-57
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• 1995

Rice Processing Complex(RPC) have being constructed with a rice mill plant and a facility of drying and storage to overcome problems caused by UR and to produce good quality of rice. An optimal design of a rice mill plant was required to successfully construct and operate it. The development of a simulation model was essential to the design of a rice mill plant. So, all the objectives of this study were to develop a simulation model for the design of a rice mill plant and to develop and evaluate the rice mill system. In this study the simulation model was developed to design a rice mill plant using SLAMSYSTEM, one of simulation languages. The results of this study were as followings. 1. A simulation model was developed with SLAMSYSTEM to represent the processes of a rice mill plant. The simulation model was used to design a rice mill pilot plant with the capacity of 0.5 ton per hour. The rice mill pilot plant was analyzed by the model with alternatives. 2. In the simulation the rice mill system was much influenced by the separating efficiency of a brown rice separator. Especially, the bottleneck of grain flow occurred at the buffer tank for brown rica. separator under 50% separating efficiency of brown rice separator. Hence, as the alternative simulation was conducted under 60% , 70% separating efficiency of brown rice separator, the bottleneck of the system could be minimized at the 60% separating efficiency of brown rice separator. 3. In the alternative simulation the bottleneck of the system was minimized under the hulling capacity of 1 t/h and 60% separating efficiency of brown rice separator with the capacity of 1 t/h. Under such a condition the max. weight of waiting entities at buffer tanks was less 250kg. So, the capacities of the buffer tanks were determined in the basis of simulation results. 4. The milled rice recovery and head rice recovery of the milling system were 74% and 92% in the simulation, respectively. These results of simulation almost corresponded to those of actual rice mill plants. The developed simulation model could be well applied to design a rice mill plant.

• 한국해양공학회지
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• 제33권3호
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• pp.205-213
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• 2019

Recently, because of the global recession of the offshore plant industry and low-cost orders, there has been increasing interest in strengthening the competitiveness of domestic companies for the design and production technologies of offshore plants. However, in the offshore plant design field, the Plant Design Management System (PDMS), which is a 3D CAD program for plant layout developed by AVEVA Marine, is already commonly used as offshore plant design software and widely used in large domestic shipyards and cooperative design companies. Under this background, we have been thinking about ways to design better with the existing software. In this study, we developed a parametric design program to maximize the efficiency and reduce the working time for offshore plant electrical outfit production design based on the Programmable Macro Language (PML) of PDMS. We also examined its performance. By applying the developed program to the offshore plant module selected as an application example, it was confirmed that a 50% improvement in the work efficiency of cable tray design could be obtained compared with the existing method, with work efficiency improvements of 80% or more in other field design work.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집D
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• pp.721-725
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• 2001

The main reason for applying pulverizer classifier-rotary type in fossil power plant is boiler high efficiency and energy saving movement in the government. This study intends to analyze the boiler efficiency through the pulverizer classifier-rotary type improvement in thermal power plant and makes its comparison to that of the used fixed type.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집D
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• pp.715-720
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• 2001

The main reason for applying positive pressure variable clearance packing in fossil power plant is high efficiency and energy saving movement in the government. This study intends to analyze the turbine efficiency through the shaft packing improvement in thermal power plant and makes its comparison to that of the used packing.