• Journal of the Semiconductor & Display Technology
• /
• v.18 no.4
• /
• pp.87-91
• /
• 2019

The diagnosis of the failure for the existing electrical facilities was based on regular preventive maintenance, but this preventive maintenance was limited in preventing a lot of cost loss and sudden system failure. To overcome these shortcomings, fault prediction and diagnostic techniques are critical to increasing system reliability by monitoring electrical installations in real time and detecting abnormal conditions in the facility early. As the performance and quality deterioration problem occurs frequently due to the increase in the number of users of the motor pump, the purpose is to build an intelligent control system that can control the motor pump to maximize the performance and to improve the quality and reliability. To this end, a vibration sensor, temperature sensor, pressure sensor, and low water level sensor are used to detect vibrations, temperatures, pressures, and low water levels that can occur in the motor pump, and to build a system that can identify and diagnose information to users in real time.

• Fire Science and Engineering
• /
• v.26 no.5
• /
• pp.85-91
• /
• 2012

This paper analyzed firefighting officers' use situations such as the use time, maximum working pressure, hose diameter, etc. of fire pumps at fire sites and carried out various performance tests by pressures, hose diameters and quantities of fire pumps based on its results because the waterproof performance criterion for a fire pump installed in a fire engine is different from the operation situations at the site and is not clearly prescribed. As a result of site survey, the site uses a higher pressure than the standard water discharge pressure (0.85 MPa) or the high-pressure water discharge pressure (1.4 MPa) prescribed by the approval Standard of the fire pump performance on fire truck. In addition, as a result of pump performance test, the discharged water flow rate, water discharge pressure, etc. was measured to be very different from the currently prescribed the approval standard depending on the hose diameter and firefighting nozzle, so the result of this study proposes a new standard.

• Journal of Power System Engineering
• /
• v.21 no.6
• /
• pp.79-85
• /
• 2017

A heat pump system is a highly efficient, eco-friendly device which consumes a small amount of energy and supply a lot of energy for heat formation. In addition, it is a single device system that has low generation effect about carbon dioxide. There are many researches related to the electronic expansion valve and the heat pump, but the detailed data analysis of each influence is insufficient. In this study, the cooling capacity and COP of the heat pump system were investigated by varying frequency of the inverter connected to compressor, inlet temperature of chilled water into evaporator and inlet temperature of cooling water into condenser. The results are as follows : (1) The cooling capacity increased as the inverter frequency, inlet temperature of chilled water into evaporator increased, and inlet temperature of cooling water into condenser decreased. (2) The COP increased as the frequency of inverter, inlet temperature of cooling water into condenser decreased and the inlet temperature of chilled water into evaporator increased.

• Fire Science and Engineering
• /
• v.26 no.4
• /
• pp.10-17
• /
• 2012

This study classifies the fire suppression measures implemented by wooden temples into four types according to availability of the pump trucks (water tanks) at the fire sites. And this study outlines the strategies and methods based on each type of fire suppression measure. The results show that the fire suppression strategy applied in general buildings is also employed in temples where pump trucks (water tanks) and fire-fighting water are available. For temples where trucks and water are not available, the helicopter, water bag, fire suppression strategy focused on water supply link, automatic transmission system of a fire engine's level by using radio communication network, and water bladder are used. In addition, general four-wheel-drive vehicles equipped with fire fighting tools such as motor pump, hose, nozzle, and water bladder should be deployed in fire stations around the temples. A fire suppression strategy using A-type ladders is also required.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2022.05a
• /
• pp.458-458
• /
• 2022

It is essential to reduce global carbon emissions, mainly from energy use. The water supply and distribution sector is a vital part of human society and is one of the primary energy consumers. The procurement and distribution of water require electricity to operate the pump to deliver water to users with sufficient pressure. As the water users are spatially distributed over a wide area, the energy required to deliver water to each user differs depending on the corresponding supplying element (reservoir, tank, pipe, pump, and valve). This difference in energy required for each user also comes with a difference in pressure availability which affects the level of service for individual users and the whole network. Typically, there is a disproportion where users close to the source experience excessively high pressure with low energy consumption. In contrast, remote users need more energy to get the minimum pressure. This study proposes the Energy Return Index (ERI) to quantify the pressure return from particular energy consumption to supply water to each node. The disproportionality can be quantified and identified in the network using the proposed ERI. The index can be applied to optimize the network elements such as pump operation and tank location/size to reach a balanced energy consumption with the appropriate level of service.

• International Journal of Computer Science & Network Security
• /
• v.24 no.4
• /
• pp.197-205
• /
• 2024

This paper presents a fully automated stand-alone irrigation system with GSM (Global System for Mobile Communication) module. Solar energy is utilized to power the system and it is aimed to conserve water by reducing water losses. The system is based on a DC water pump that draws energy from solar panels along with automated water flow control using a moisture sensor. It is also fitted with alert and protection system that consists of an ultrasonic sensor and GSM messages sender that transmits signals showing the levels of the water in the reservoir and the battery charge. The control system is designed to stop the water pump from pumping water either when the battery level drops to equal or less than 10% of its full charge, or when the water level becomes less than 10 cm high in the reservoir. The experimental results revealed that the system is appropriate to use in remote areas with water scarcity and away from the national grid.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2012.10a
• /
• pp.737-738
• /
• 2012

• Progress in Medical Physics
• /
• v.14 no.1
• /
• pp.51-53
• /
• 2003

The results of the measured specific activities of Rn-222 in water for public water supply pump houses (wells) of Ulaanbaatar City, Mongolia using the HP-Ge gamma-spectrometer, are described. The average of the specific radioactivies for the Rn-222 were for the station “Centre” 82.59 Bq/l, station “Combinat” 91.35 Bq/l and station “Makh” 158.25 Bq/l, respectively.

• Journal of Electrical Engineering and Technology
• /
• v.10 no.3
• /
• pp.1304-1310
• /
• 2015

In remote islands, due to expense of existing generation systems, installation of photovoltaic cells (PVs) and wind turbines has a chance of reducing generation costs. However, in island power systems, even short-term power fluctuations change the frequency of grids because of their small inertia constant. In order to compensate power fluctuations, the authors proposed the power consumption control of pumps which send water to tanks. The power control doesn’t affect water users’ convenience as long as tanks hold water. Based on experimental characteristics of a pump system, this paper shows methods to determine reference power consumption of the system with compensation for short-term PV fluctuations while satisfying water demand. One method uses a PI controller and the other method calculates reference power consumption from water flow reference. Simulations with a PV and a pump system are carried out to find optimum parameters and to compare the methods. Results show that both PI control method and water flow calculation method are useful for satisfying the water demand constraint. The water demand constraint has a little impact to suppression of the short-term power fluctuation in this condition.

• Transactions of The Korea Fluid Power Systems Society
• /
• v.4 no.3
• /
• pp.7-12
• /
• 2007

This paper presents an energy saving hydrostatic pressure exchanger for sea water desalination equipment. In a reverse osmosis(RO) system for desalinating sea water, more than 70 percent of the supplied sea water, brines which were impassable through RO membrane are bypassed, resulting in high energy losses. In this paper, a hydrostatic pressure exchanger consisting of an embedded water hydraulic piston motor and a water hydraulic piston pump was proposed and investigated in order to recover the energy of the bypassed brines. The pressurized brines are supplied to the embedded water hydraulic piston motor as power sources and the water hydraulic piston pump is driven by the output torque of the embedded water hydraulic piston motor as well as electric motor. Consequently, the energy of the bypassed brines can be recovered. To examine the electric energy saving characteristics of the hydrostatic pressure exchanger, a simulation model was constructed using commercial software and experiments were conducted. Through the results of simulation and experiment, the feasibility of the electric energy saving effect of the proposed hydrostatic pressure exchanger was investigated.