• Economic and Environmental Geology
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• v.38 no.6 s.175
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• pp.717-729
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• 2005

Peak cooling load of large buildings is generally greater than their peak heating load. Internal and solar heat gains are used fur selection of adquate equipment in large building in cold winter climate like Canada and even Korea. The cost of geothermal heat exchanger to meet the cooling loads can increase the initial cost of ground source heat pump system to the extend less costly conventional system often chosen. Thermal ice storage system has been used for many years in Korea to reduce chiller capacity and shift Peak electrical time and demand. A distribution system designed to take advantage of heat extracted from the ice, and use of geothermal loop (geothermal heat exchanger) to heat as an alternate heat source and sink is well known to provide many benifits. The use of thermal energy storage (TES) reduces the heat pump capacity and peak cooling load needed in large building by as much as 40 to $60\%$ with less mechanical equipment and less space for mechanical room. Additionally TES can reduce the size and cost of the geothermal loop by 1/3 to 1/4 compared to ground coupled heat pump system that is designed to meet the peak heating and cooling load and also can eliminate difficuties of geothermal loop installation such as space requirements and thermal conditions of soil and rock at the urban area.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.3
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• pp.553-558
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• 2019

Global auto parts companies are making efforts to develop EWP(: Electric Water Pump) which is one of the core parts of environment friendly car. In eco-friendly automobiles, an independent cooling system is used rather than a cooling system that is linked to an internal combustion engine. Therefore, the research and development of the water pump operating separately from the engine and the related production system are being actively carried out. In order to overcome the shortcoming of EWP of PPS material suitable for injection system, G company which is a global parts company that researches and develops EWP around SUS and is in the process of developing robot-based production equipment for mass production. In this paper, a heat shock simulation system is designed and implemented that works with the robot-based production system to test the performance of the produced EWP. By using this system, it is possible to test the EWP in an virtual environment similar to the actual environment, thereby reducing the defect rate of the product. At the same time, all the data produced during the entire process for testing can be stored, which can be utilized in the future development of CPS(: Cyber Physical System) of EWP system based on big data.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.11
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• pp.913-918
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• 2016

A three-way reversing valve, which provides rapid and accurate changes in the water flow direction without requiring any precise control device, is used in automotive washing machines to remove oil and dirt that remain on the machined engine and transmission blocks. Because of the complicated shape of the bottom-plug, however, cavitation occurs in the plug. In this study, the cavitation index and POC (percent of cavitation) were used to quantitatively evaluate the cavitation effect occurring in the bottom-plug on the downstream side. An optimal shape design was conducted via parametric study with a simple CAE model to avoid time-consuming CFD analysis and hard-to-achieve convergence. To verify the results of the numerical analysis, a flow visualization test was conducted using a specimen prepared according to ISA-RP75.23. In this test, the flow characteristics, such as cavitation occurring on the downstream side, were investigated using flow test equipment that included a valve, pump, flow control system, and high-speed camera.

• Journal of the Korean Society of Propulsion Engineers
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• v.9 no.3
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• pp.74-84
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• 2005

This paper include the investigation of finding the system characteristics of facility by simulating open-type turbo-pump fed system, which has commercial control valves, using AMESIM (Advanced Modeling Environment Simulation) commercial software. After developing a flight-type control valve on the basis of the results, the system characteristics of facility for control and valve tests is estimated. Especially, one of purposes of this paper is to find PID value of each commercial control valve in the facility for system test. To find suitable control logic, PI and PID modes are also compared. This paper also introduces design parameters of valve and equipment for thrust control and TDS simulation, which are using control valves.

• Fire Science and Engineering
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• v.31 no.1
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• pp.58-62
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• 2017

There is a growing need for seismic resistance design. But it is controversial that standards of sway brace device in non-structural elements for buildings like pump waterway is vary widely. Therefore, in this study to get a valid range of sway brace device in seismic resistance design, using load test of sway brace device. As a result, load of safe range from 0 to 18.5 kN and under 29.4 kN, no structural fault of sway brace device. And using internet of things get a data of seismic resistance design from sensor node like accelerometer, GPS, tilt sensor and temperature sensor through steps of sampling and prediction. These results will be acceptable for monitoring system for seismic resistance in non-structural elements.

• Journal of Biosystems Engineering
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• v.31 no.3 s.116
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• pp.161-167
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• 2006

The purpose of this study is to find the optimal conditions of PCM slurry manufacturing equipment for saving the marketing cost and keeping the original quality of products. In addition, the characteristics of the movable container for shipping or distributing products is analysed. The major results are as follows. 1. PCM thermal storage system is designed with the conditions of temperature($-5{\sim}10^{\circ}C$), cold chain time(30 minutes), and one time usage(50 liter). This system includes tank, freezer, circulating pump, cycle type heat exchanger, swelling tank, equipment of supplying PCM supplying unit includes cold tank, cycle type heat exchanger, suction unit and control equipments, etc. 2. After ability test of PCM thermal storage system, it shows that the required freezing time of PCM thermal storage system is less than one of the previous system. The reason is that churn (top and bottom) and compulsion circulation are occurred simultaneously and unit cooler type method is better than chiller type method. 3. By the experiment of transportation latent heat container, it is decided that the best container is $K_1$ with latent heat temperature($0{\sim}5^{\circ}C$) and density(0.15%). However, for $K_l\;and\;K_2$, it is necessary more studies on latent heat thermal conditions and conditions of making method.

• Journal of Drive and Control
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• v.12 no.4
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• pp.71-76
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• 2015

The therapy of injecting a fixed amount of a prescribed drug for a predetermined time is an effective treatment in relieving pain during anticancer treatments. Due to recent medical technology development, cancer is currently classified as a disease that can be managed in the patient's lifetime. If patients were able to use a drug delivery system that was portable, sustainable and had an accurate flow control, they would be able to inject medication whenever they need. In this study we developed a piezoelectric micropump for a drug delivery system by designing a pump chamber, check valve and diaphragm. We also developed a driving circuit that consumes low power and to which we applied a variety of signals. We fabricated a portable drug delivery system with this piezoelectric micropump and driving circuit. In addition, through a performance test, we confirmed that the system can precisely control the drug flow rate.

• International Journal of Advanced Culture Technology
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• v.8 no.2
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• pp.246-251
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• 2020

Dimethyl Ether(DME) engine use a highly efficient alternative fuel having a great quantity of oxygen and has a advantage no polluting PM gas. The existing DME fuel cam material is a highly expensive carbide alloy, and it is difficult to take a price advantage. Therefore the study of replacing body area with inexpensive steel material excluding piston shoe and contact area which demands high characteristics is needed. The development of WC-Ni base carbide alloy optimal bonding composition technique was accomplished in this study. To check out the influence of bonding temperature and time, bonding characteristics of sintering temperature was experimented. The hardness of specimen and bonding rate were measured using ultrasound equipment. The bonding state of each condition was excellent, and the thickness of mid-layer, temperature and maintaining time were measured. The mid-layer thickness according to bonding temperature and maintaining time were observed with optical microscope. We analyzed the micro-structural analysis, formation of bonding specimen, wafer fabrication and fuel cam abrasion test. Throughout this study, we confirmed that the fuel cam for DME engine which demands high durability against velocity and pressure is excellent.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.12
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• pp.2944-2951
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• 2013

Recently, the offshore plant has been revived by rise in oil prices and energy consumption. Due to the external environmental impact, the ballast system is essential for an offshore plant. The ballast system for the existing offshore plant, consist of pump 6EA and Ballast tank 4EA, is performed by the tilt control. However, this system is vulnerable to a failure due to the fact that a lot of equipment needs to be installed within the system. In this paper, a new concept of ballast system and the control algorithm based on IT is proposed. Simulator has been created to test the proposed system and algorithm, and as a result, it has proven that it is controlled stably.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.9
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• pp.35-41
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• 2022

The moisture content of many inorganic sludges is less than 70% during dewatering. Hence, a mono or piston pump cannot feed the sludge dryer. Thus, most inorganic sludge should be moved to a landfill or recycled directly without any reduction method. This development was invented to apply cyclone dryers using air and specially designed for the continuous injection of sludge sources by negative pressure and high air velocity for low moisture inorganic matter. Therefore, wastewater sludge and raw water treatment sludge discharged from various industrial fields might be settled by this development. The cyclone dryer was commercialized useful as moisture reduction equipment. This development was applied using a sludge injection system for sludge feeding and under the cooperation of ejector design computational fluid dynamics. Furthermore, this paper presented good ejector model results, blowing an airflow of 264 m³/min at an actual performance test.