• Korean Journal of Agricultural Science
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• v.47 no.4
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• pp.1057-1069
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• 2020

For most upland crops in Korea, underground water is used to ensure an adequate water supply. Thus, surface water storage tanks are needed to supply surface water from reservoirs or streams. This study discusses the design, manufacture and monitoring of a water storage tank capable of reliably supplying water to crops and preventing the inflow of floating debris. The study was conducted in an apple orchard in Yesan-gun, Chungcheongnam-do in Korea. Based on the water requirements of the crops and size of the orchard, a required flow volume of about 0.6 ㎥·h-1 was determined, along with a surface water storage tank capacity of 1.2 ㎥. Following a comparison with other materials, stainless steel (STS) was used to construct the water tank. The tank was designed to provide 14 hours of irrigation, enabling a small-capacity, cost-efficient tank design to be used. A surface water irrigation test was performed using the surface water storage tank. The average surface water irrigation flow rate was 0.00045 ㎥·m-2·h-1. The water quality test showed that the pH, suspended solids (SS), total nitrogen (TN), and total phosphorus (TP) values satisfied the reference values for agricultural water. The test results showed that the surface water storage tank evaluated in this study allows for crop irrigation when there is a lack of groundwater during droughts.

• 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.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.3
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• pp.927-935
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• 2013

In this study, reservoir routings for 1 hour-50 year precipitation frequency were carried out at the Engineering Water Fall and the Amphitheater located at the downstream of Seoul National University Dam. Main analysis was focus on the following matters: (1) storage amount by the tank; (2) reduction of the outflow and the peak water surface elevation; (3) change of phase lag time; and (4) design of new boxes at the inlet and outlet of storage tank. As for the storage tank of $25,000m^3$ built in the Amphitheater area, the tank induced 49.43 % storage effect, 28 min. phase lag time, and reduced the peak outflow by 49.64 %. In addition, the peak water surface elevation was lowered by 35 cm compared with that of $15,000m^3$ storage tank. It is concluded that combined management of previous storage facility and new underground storage tank would control the excessive rainfall runoff efficiently.

• Journal of Korea Water Resources Association
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• v.36 no.3 s.134
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• pp.455-464
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• 2003

In this paper, the experiments with installing a rainfall storage tank in the sub-surface were conducted and the reduction rates of the total runoff volume were investigated. The analysis were conducted based upon the variations of the rainfall intensity, surface coverage and surface slope. The reduction rate of the runoff volume was varied from 42.3% to 52.9% with the soil in the bank of the Seung Gi stream. In the experiments, the rainfall intensities were varied from 40mm/hr to 100mm/hr and the results indicate that the direct runoff reduction can be obtained with the installation of the rainfall storage tank in the sub-surface. The variation of the stored volume in the tank is very large in the mild slope but very small in the steep slope with over 3% slope. With this results, the reduction of the direct runoff volume for the longtime flood is expected with the installation of the rainfall storage tank in the region haying the steep slope such as the mountain area.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.23 no.5
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• pp.327-333
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• 2011

In the present work, a new freeze protection method has been proposed for a natural circulation system of solar water heater. Though electrothermal wire is popularly used for the purpose, there are freezing troubles by wire cut-off and shortage of excessive electric power consumption. In the experimental device, hot water in storage tank was used to heat the outlet pipe from the tank if the pipe surface temperature falls lower than a set point. The cold water pipe to the storage tank was installed to directly contact the hot water pipe surface temperature rose by transferred heat.

• Journal of Sensor Science and Technology
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• v.27 no.5
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• pp.352-356
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• 2018

This paper relates to a technology for monitoring a liquefied gas storage tank in the special gas field where demand is increasing owing to the continuous growth of related fields such as the semiconductor, display, and ICT convergence electronics industries. We have proposed a system for real - time monitoring using wireless sensor network technology, and implemented a system consisting of a sensor unit, transmitter module, and receiver module to be attached to a liquefied gas storage tank. The system was applied to LCO2 tanks among various liquefied gas storage tanks to verify the feasibility. The storage tanks employed in the experiments has capacities of 16,179 l and was 1,920 mm in inner diameter. Furthermore, the density was 1.03 g/l. The measured data were compared with reference data on the remaining gas level versus the $CO_2$ height of the surface, expressed using a conventional water meter, provided by an existing storage tank supplier. The experimental results show that the data is similar to the standard data provided by the tank supplier, and has a high accuracy and reliability within an error range of 0.03%.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.2
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• pp.80-87
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• 2001

Microencapsulated PCM particles are mixed with distilled water and utilized to evaluate its characteristics and performance as a thermal storage medium transporting heat. For the present study, tetradecane(C$_14H_30, T_m=5.5^{\circ}C$) is capsulated in the core with the melamine of its surface. The size of particles is well-controlled under 10${\mu}{\textrm}{m}$ in the way of in-situ polymerization with melamine-formaldehyde resin. For the experiment, the concentrations of slurries are prepared for 20wt%, 30wt%, and 40wt%. The results are compared with those of water and 100% tetradecane oil. The pure water and tetradecane start solidifying within 20 minutes after introducing cooling water into the thermal storage tank whose tank whose flow rates are varied by 125cc/min, 250cc/min, and 500cc/min. However, MicroPCM slurries are required relatively longer period of time for their phase change than pure phase change materials. That is, the entrained MicroPCM particles control its heat transfer in terms of natural convection and conducting to them.

• Journal of the Society of Naval Architects of Korea
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• v.40 no.6
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• pp.88-95
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• 2003

Liquid storage rectangular tank structures are used in many fields of airplane and marine engineering. Fatigue damages are sometimes observed in these tanks which seem to be caused by resonance. Therefore it is essentially important to estimate vibration characteristics of tank structures. Many Investigators studied the vibration of cylindrical and rectangular tank structures containing still fluid. In general, the eigenbehavior of interior liquid is characterized by the sloshing mode while that of the structure by the bulging mode. However, the structure deformation to the sloshing mode and the liquid free-surface fluctuation to the bulging mode have been neglected in the classical added-mass computation. in the present paper, we study the vibration characteristics with sloshing mode effect.

• Journal of the Korean Society of Visualization
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• v.18 no.2
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• pp.28-34
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• 2020

In this study, we numerically investigated the thermal stratification in solar seasonal thermal storage tanks. The vertical in/out flows were unsuitable for the thermal stratification in a large scale. The effect of an aspect ratio (AR) on the thermal stratification was investigated. When AR was less than 2, water adheres and flows along the upper wall due to buoyance and the surface effect. Thereafter, hot water flows down and a large scale vortex occurs in entire tank. For high AR, jet flows ejected from the inlet pipe impinges to the opposite wall and splits. The divided flows create two vortex flows in the upper and lower regions. These different flows strongly influence temperature and thermal stratification. The thermal stratification was evaluated in terms of the thermocline thickness and degree of stratification. Compared to ARs, the maximum degree of stratification was obtained with AR of 5 having the minimum thermocline thickness.

• Ocean Systems Engineering
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• v.8 no.1
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• pp.57-77
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• 2018

The present paper deals with the finite element analysis of water tanks with rigid baffle. Fluid is discretized by two dimensional eight-node isoparametric elements and the governing equation is simulated by pressure based formulation to reduce the degrees of freedom in the domain. Both free vibration and force vibration analysis are carried out for different sizes and positions of block at tank bottom. The fundamental frequency depends on block height and it reduces with the increase of block height. The variation of hydrodynamic pressure on tank walls not only depends of the exciting frequency but also on the size and position of rigid block at tank bottom. The hydrodynamic pressure has higher value when the exciting frequency is equal and lower than the fundamental frequency of the water in the tank. Similarly, the hydrodynamic pressure increases with the increase of width of the block for all exciting frequencies when the block is at the centre of tank. The left and right walls of tank have experienced different hydrodynamic pressure when the block is placed at off-centre. However, the increase in hydrodynamic pressure on nearest tank wall becomes insignificant after a certain value of the distance between the wall and the rigid block.