• Journal of Korean Society of Water and Wastewater
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• v.21 no.1
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• pp.131-138
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• 2007

A rainwater utilization facility consists of its catchment area, treatment facility, storage tank, supply facility and pipes in general. The rainwater storage tank which occupies the largest area of the facility has been usually considered quantitatively for determining the storage capacity. Hence, there is little information on water quality improvement by sedimentation in a rainwater storage tank in operation. In this study, we measured the rainwater quality in a rainwater storage tank in operation during late spring and summer, and showed water quality improvement of turbidity removal of 25~46% by sedimentation in a rainwater storage tank under a fixed water level without inflow and outflow after runoff ceased. It is necessary to have a considerable distance between the inlet and outlet of the tank and, if possible, it is recommended that the design should allow for an effective water depth of over 3 m and supply rainwater near the water surface. The operation method which increases the retention time by stopping rainwater supply for insuring low turbidity is recommended when the turbidity of rainwater runoff is high. And also more efficient operation and maintenance of the rainwater utilization facility is expected through the tailored design and operation of the facility considering particle removal and behavior.

• The KSFM Journal of Fluid Machinery
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• v.18 no.3
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• pp.20-25
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• 2015

In this study, there are 6 mixers that are installed in a 600,000 barrel tank. We identified internal flow characteristics of floating roof tank with varying the number of operation from 4 to 6 because mixer is a variable that influence flow characteristics of the tank. And while varying an angle from Right $60^{\circ}$, Right $30^{\circ}$, Left $30^{\circ}$ to Left $60^{\circ}$, we identified internal flow characteristics of the tank. As a result, maximum velocity of flow was 0.02m/s stationarily when we changed the number of operation from 4 to 6. Maximum velocity of flow by change of an angle was from 0.42m/s to 0.47m/s. Therefore, we identified that these factors don't have a great influence on internal flow characteristics of a tank by investigating results with varying the number of operation and an angle.

• Journal of Environmental Science International
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• v.18 no.6
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• pp.603-608
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• 2009

Activated sludge sewage treatment processes are difficult to be controlled because of their complex and nonlinear behaviour, however, the control of the dissolved oxygen level in the reactors plays an important role in the operation of the facility. For this reason, this study is designed to present a system which accurately measures DO, MLSS, pH and ORP in the aeration tank to alleviate situations above and provide the automatization of a sewage treatment plant (STP) using new DO control system. The automatic control systems must be guaranteed the accuracy. Therefore, the proposed automatic DO control system in this study could be commercial applications in the aeration tanks by means of operating cost analysis and user-friendly for operation and maintenance. We could get accurate data from the lab tank which has water quality checker because there was no vortex and air bubble during the measurement process. Improvement of confidence in the lab tank enabled effective and automatic operation of sewage treatment plants so that operation costs and manpower could be saved. If this result is put in place in every sewage treatment plant nationwide for practical purposes, it is estimated to cost 18.5 million dollars in installing the lab tank and to save 9.8 million dollars in management cost a year, except for cost saved by automation.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.11 no.1
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• pp.133-146
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• 1999

The charge operation of an ice storage system has been analyzed in this paper. The thermal characteristics of major components of the ice storage system. i.e., the refrigerator and the ice storage tank are evaluated from performance tests on an existing ice storage system. Based on the measured data for thermal characteristics, a simulation is carried out for the charge operation and the effect of the refrigerator size on the system performance is investigated. The results indicate that the larger the refrigerator size for a given storage capacity, the lower the inlet temperature of the ice storage tank so that the lower the efficiency of charge operation. It is also found that there exists an optimal size of the refrigerator with which the ice storage at the end of the charge operation is maximized, but the complete charge is not possible even with the optimally sized refrigerator. This leads to the result that the design capacity of the storage tank should be larger than the required amount of cold energy for the daytime cooling considering the practically chargeable amount of cold energy during the nighttime. Where the cooling load sharing of the storage is 40%, the nominal capacity of an ice storage tank needs to be larger than the required storage amount by 30%.

• Proceedings of the Safety Management and Science Conference
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• 2001.11a
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• pp.193-202
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• 2001

The individual rotten water purification tank recently discharges wastewater and sewage through the outlet without purification ability. The outlet water and affiliated water purification tank with microorganism cultivator tank cultivates microorganism and then drops the value BOD, COD of sewage and discharges the quality of water into the outlet. The blower and water pump operating continuously prompts the waste of energy and deterioration of equipment. Each room of deposition tank, foaming tank, microorganism cultivator tank is equipment with the sludge detection senses so it can detect the density of each room. The power-drive plant of the blower and water pump which ate the system cultivating the microorganism must be made as fuzzy controlization (If the sludge amount of each room become higher, the rate of operation of blower and water pump must heighten, on the contrary, in case of row sludge amount, the total handling amount and microorganism handling amount of each room of control. Tank reducing the rate of operation must be DB. At present, the blower amount in proportion to the sludge and oxygen demanding amount has to control. Each mom must be checked outlet level of the outlet, also each room must flow backward discharge materials, and must operate feed-back control until we want to be come as a below value of BOD/COD(10PPM ; KS).

• Journal of the Korea Safety Management & Science
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• v.3 no.4
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• pp.53-63
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• 2001

The individual rotten water purification tank recently discharges wastewater and sewage through the outlet without purification ability. The outlet water and affiliated water purification tank with microorganism cultivator tank cultivates microorganism and then drops the value BOD, COD of sewage and discharges the quality of water into the outlet. The blower and water pump operating continuously prompts the waste of energy and deterioration of equipment. Each room of deposition tank, foaming tank, microorganism cultivator tank is equipment with the sludge detection senses so it can detect the density of each room. The power-drive plant of the blower and water pump which are the system cultivating the microorganism must be made as fuzzy controlization (If the sludge amount of each room become higher, the rate of operation of blower and water pump must heighten, on the contrary, in case of row sludge amount, the total handling amount and microorganism handling amount of each room of control. Tank reducing the rate of operation must be DB. At present, the blower amount in proportion to the sludge and oxyzen demanding amount has to control. Each room mus be checked outlet level of the outlet, also each room must flow backward discharge materials, and must operate feed-back control until we want to be come as a below value of BOD/COD(10PPM ; KS).

• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.5
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• pp.721-729
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• 1994

In this paper an optimization of the industrial congeneration system which have a thermal storage tank is proposed for the short-term operation strategy. Short-term operation costs of topping cycle and bottoming cycle are calculated by using the proosed model of a thermal storage tank. Simulation result of four cases are compared and analyzed each other.By these simulations which are similar to real operation circumstances. the validity of the proposed model is verified.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.6 no.2
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• pp.93-102
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• 1994

It is the goal of this study to provide the essential data for design and operation of optimum water supply system. Experimental and theoretical analyses have been conducted for various parameters, for example, volume and air percent of pressurizing tank, pump speed and pressure range inside tank, etc. Pressure inside tank with time, flow rate, energy consumption rate and pump operation time have been obtained for design and operating parameters to optimize the components and to establish the operating method of system, and therefore to contribute to the development of technology from a point of view of the improvement of quality, the enhancement of system efficiency and the reduction of construction cost.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.7
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• pp.616-622
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• 2012

In this paper, we examined the problems of the flare operation of tactic maneuvering flight of fighter aircraft with 150GL center external fuel tank and proposed the possible solution of it's operation. The damage scope of horizontal fin of fuel tank and flare trajectory when the flare ejected from the maneuvering aircraft were analyzed by the wind tunnel test and the numerical analysis. We investigated the two different option to avoid the damage of fin; i) the adjustment of flare dispenser angle and ii) the change of horizontal fin's shape. For the considering of practical operation of present system, we chose the second option. We estimated the drop safety of external fuel tank with redesigned fin by the wind tunnel experiments.

• Journal of the Korea Institute of Military Science and Technology
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• v.3 no.1
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• pp.218-230
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• 2000

In the weapon system development/operation stage, the goals of RAM activities are to support the cost effective performance optimization in design and operation supports. In the study, the main contents are as follows; 1) To establish the operational concept and circumstance of the subsequent tank, the combat/operation scenario, the operational mode summary and mission profile for subsequent tank development are analyzed. 2) To evaluate the administrative and logistics down time for subsequent tank, the prefigured logistics circumstance and maintenance system are analyzed. 3) To calculate the RAM object values, a mathematical model for the user are developed. 4) To examinate the propriety of the RAM object values, the combat readiness are reviewed. The obtained RAM object values are provided to predict and analyze for the combat readiness, staying power, mission reliability, equipment availability and the logistic support capability.