• Journal of the Korean Society of Safety
• /
• v.33 no.3
• /
• pp.46-51
• /
• 2018

A basic sprinkler system is a fire extinguishing system that can be easily installed in a fire-vulnerable place such as a publicly used establishments. However, the publicly used establishments are not only complicated in structure, but also have a large amount of flammable interior materials, and the users are not normally in a normal state, which is a very dangerous fire-fighting object. Therefore, due to the low fire extinguishing performance of the basic sprinkler system installed in the publicly used establishments, the fire suppression control can not be performed quickly in case of fire, which may increase the life and property damage. In this study, the cases of quantitative changes of extinguishing water used in basic sprinkler system and the cases of addition of additives such as wetting agents, reinforced agents to improve extinguishing performance were compared. Experimental results showed that the extinguishing performance was improved as the quantity of extinguishing water increase and the reinforced agents showed similar performance to that of 60% increase in the amount of extinguishing water. The cooling time to $200^{\circ}C$ and oxygen concentration were improved up to 14.3% and 34.5%, respectively. In the case of using the wetting agent, the cooling time to $200^{\circ}C$ and oxygen concentration did not show any significant improvement, but showed the effect of preventing deep seated fire. In order to prevent loss of life and property, it is necessary to improve the performance of the basic sprinkler system by increasing amount of extinguishing water or using additives like reinforced agents.

• Journal of the Korean Society of Safety
• /
• v.32 no.4
• /
• pp.16-21
• /
• 2017

The sprinkler system is a basic fire extinguishing system that uses water as an extinguishing agent. In order to evaluate the fire extinguishing performance of the sprinkler system, information such as the discharge angle, discharge speed, discharge pressure, flow rate, and water droplet size of the installed head are required. However, there is a lack of research on droplets size compared to other requirements. In this study, to evaluate the extinguishing characteristics of sprinkler system, the droplet size distribution was measured for various types of sprinkler heads actually used. The size of the droplet was measured using laser diffraction method. The 50% cumulative volume distribution ($D_{v50}$) according to discharge coefficient(K factor) was $540{\mu}m{\sim}695{\mu}m$ for K50, $542{\mu}m{\sim}1,192{\mu}m$ for K80, $980{\mu}m{\sim}1,223{\mu}m$ for K115 and $1,188{\mu}m{\sim}1,234{\mu}m$ for K202. Based on the measured results, the vaeiance of the droplet particle distribution and the distribution ($D_{v50}$) according to discharge coefficient(K factor) was $540{\mu}m{\sim}695{\mu}m$ for K50, $542{\mu}m{\sim}1,192{\mu}m$ for K80, $980{\mu}m{\sim}1,223{\mu}m$ for K115 and $1,188{\mu}m{\sim}1,234{\mu}m$ for K202. Based on the measured results, the vaeiance of the droplet particle distribution and the Rosin-Rammler index value are presented. As a result of the fire simulation with FDS, it was confirmed that the performance difference occurs according to the water droplet size distribution even when the same amount of water is used. Therefore, the extinguishing performance of the sprinkler system should be evaluated considering the droplet size distribution according to the sprinkler head type.

• Journal of the Korean Society of Safety
• /
• v.33 no.2
• /
• pp.32-38
• /
• 2018

The sprinkler system is a basic fire extinguishing system widely used, but there is a lack of quantitative assessment of its performance. In this study, to evaluate the fire extinguishing performance of the sprinkler head according to the discharge coefficients, experiments were conducted. Experimental sprinkler heads were selected with heads having K50, K80 and K115 water discharge coefficients, and the fire source was assumed to be an indoor fire in Class A Model 1. As experimental results, the time required for the fire chamber to cool down to $200^{\circ}C$ was 26 seconds for the K115 head, 414 seconds for the K80 head, and 481 seconds for the K50 head, so the cooling time of the K115 head was decreased by 94.5% compared to K50 head. In the case of restoring the oxygen concentration to 15%, the K115 head did not decrease below the oxygen concentration of 15%, and the K80 head took 145 seconds and the K50 head took 484 seconds. The lowest oxygen concentration in the fire chamber was 16.1% for the K115 head, 14.33% for the K80 head, and 11.28% for the K50 head, indicating that the K115 head was superior to the K80 and K50 heads by 13.1% and 43.7%, respectively. As the experimental results show, there is big difference in the extinguishing performance depending on the discharge coefficients of the sprinkler head. Therefore, in designing the sprinkler system, the discharge coefficients of the sprinkler head should be selected considering the heat release rate at the installation site and the fire extinguishing characteristics of sprinkler head.

• Journal of the Society of Disaster Information
• /
• v.16 no.2
• /
• pp.237-247
• /
• 2020

Purpose: This study aims to draw the problems and improvements of NFSC 103 sprinkler head discharge obstruction prevention standard to increase the fire extinguishing performance of sprinkler system in order to contribute to the protection of people's lives and property in the event of a fire. Method: NFSC 103 was compared to NFPA 13 which is the latest 2019 version in U.S in terms of sprinkler head discharge obstruction prevention. Results: This study found that NFSC 103 doesn't define even the basic concept of sprinkler discharge obstruction. And NFSC 103 doesn't have detailed standard for side wall sprinkler head discharge obstruction prevention as well as the "height" criteria of the "three times" separation rule. Conclusion: NFSC 103 needs a lot of supplements and improvements such as the addition of definition for water discharge obstructions, the adoption of sidewall sprinkler heads standard for preventing water discharge obstructions and the additional establishment of the "three times rule" considering the "height" of obstacles to promote the advance of fire safety standard equal or above fire fighting advanced country and increase the reliability for the suppression performance of sprinkler system.

• Fire Science and Engineering
• /
• v.32 no.1
• /
• pp.24-32
• /
• 2018

There are two kinds of method on hydraulic calculation of fire sprinkler system design. The one is using the computational program and the other is designer calculate system for oneself. In case of using the computational program, putting the input data in, the program calculate the friction loss, water flow, total height and so forth. If program user or designer doesn't know the basic idea and procedure of hydraulic calculation. Then, the outputs are different from each other. This paper suggests the hydraulic calculation procedure in design area as follow. Equivalent lengths of tees on the branch are selected base on the same pipe diameter which the tees are established, although the diameter of tee outlet is different. Even though there is a different friction loss of head from the other head, the pressure from the hydraulic end is bigger than a head loss, discharge flow is calculated by pressure from the hydraulic end.

• Journal of Korean Association for Spatial Structures
• /
• v.10 no.2
• /
• pp.135-145
• /
• 2010

The objective of this study is to draw basic data for the application of the fire protection planning for the future plan large enclosure buildings in Korea through an analysis of its characteristics by case studies of the domestic and foreign large scale gymnasiums. In this study, domestic building codes for the fire protection are investigated and fire detection systems, fire extinguishing systems, smoke control systems and evacuation systems of three large scale gymnasiums located at Korea and eight foreign countries are compared and analyzed. The results of this study show that infrared light fire detection system and flame detector for spacial characteristics are potentially used in fire protection systems of large scale gymnasiums: dry type sprinkler and sprinkler water gun are adopted in fire detection system; and smoke accumulation system is widely utilized in smoke control system.

• Korean Journal of Agricultural Science
• /
• v.48 no.4
• /
• pp.703-718
• /
• 2021

An irrigation monitoring system is an efficient approach to save water and to provide effective irrigation scheduling for rice cultivation in desert soils. This research aimed to design, fabricate, and evaluate the basic performance of an irrigation monitoring system based on information and communication technology (ICT) for rice cultivation under drip and micro-sprinkler irrigation in desert soils using a Raspberry Pi. A data acquisition system was installed and tested inside a rice cultivating net house at the United Arab Emirates University, Al-Foah, Al-Ain. The Raspberry Pi operating system was used to control the irrigation and to monitor the soil water content, ambient temperature, humidity, and light intensity inside the net house. Soil water content sensors were placed in the desert soil at depths of 10, 20, 30, 40, and 50 cm. A sensor-based automatic irrigation logic circuit was used to control the actuators and to manage the crop irrigation operations depending on the soil water content requirements. A developed webserver was used to store the sensor data and update the actuator status by communicating via the Pi-embedded Wi-Fi network. The maximum and minimum average soil water contents, ambient temperatures, humidity levels, and light intensity values were monitored as 33.91 ± 2 to 26.95 ± 1%, 45 ± 3 to 24 ± 3℃, 58 ± 2 to 50 ± 4%, and 7160-90 lx, respectively, during the experimental period. The ICT-based monitoring system ensured precise irrigation scheduling and better performance to provide an adequate water supply and information about the ambient environment.

• Journal of Animal Environmental Science
• /
• v.21 no.2
• /
• pp.55-64
• /
• 2015

This survey was conducted to give the basic information and temperature and humidity variation by cooling systems in dairy farms in Korea. A total of 36 farms were surveyed in Gyeonggi province with the general information of farms such as milk production, and milk quality, types of cooling systems, and its operation method of dairy farms. All of surveyed farms have cooling fan and some have 1 more cooling systems such as sprinkler, foggy systems, ventilation duct, and shower system. Although the indoor THI of cow house was decreased by either ventilation duct or foggy system during hot season, the range belongs to mild heat stress scale for dairy cows.

• Journal of the Korean Institute of Rural Architecture
• /
• v.10 no.4
• /
• pp.25-32
• /
• 2008

The prevention of disasters in cultural property is very important management and historical duties. The reason can't be measured values with monetary scale of our contemporary. Therefore, this paper was considered fire-safety as one of terrible threat-disasters about the wooden buildings. This research deal with 47 cases cultural property wooden building by whole investigation(field survey and interview) in Gangnung province. The most buildings have basic fire extinguisher; ABC powder. A few buildings are rarely installed fire extinguishing equipments; outdoor fire hydrant, heat sensor, ground sprinkler, CO2-hose-reel. But these state is very insufficient for the fire-safety in cultural property wooden buildings. Specially as particular attention in province, forest fire of regional characteristic have close relation with cultural property fire. The majority of factor against forest and building fire is to provide monitoring and security system; CCTV, Fence, Sensor, Alarm and paid guard man against incendiary. Ultimately it is necessary to construct comprehensive disaster prevention system with the organic cooperation such as National Emergency Management Agency, Cultural Heritage Administration, Forest Service, local government officials and regional citizen.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.50 no.4
• /
• pp.20-36
• /
• 2022

This study aims to provide basic data for high-quality street tree management by setting reasonable management items and appropriate unit prices by reviewing the adequacy of current street tree management. Currently, street tree management items, except for street tree pruning, use general landscape tree quantity per unit for the street tree management quantity per unit. KEPCO (Korea Electric Power Corporation) applied pruning items from standard electric production infrastructure and carried out the activities at an average unit price of 51% lower for heavy pruning and 39% lower for light pruning than the standard estimate. This was judged to be a level that could not maintain or increase the quality of street tree management. It was determined that an appropriate standard unit price for street tree management was necessary. To improve the quantity per unit for the proper management of street trees, it was necessary to review costs in the field. However, due to the absence of data on actual construction costs in the domestic landscape field, detailed items of the US RSMeans Building Construction Cost Data (RSMeans) were reviewed, and the actual construction costs were calculated by applying personal domestic expenses. As a result, the standard of the estimated unit showed a good ratio of 107% for heavy pruning of street tree pruning compared to the actual construction cost, but light pruning was underestimated with a 59% ratio. Shrub pruning was 82%, weeding was 92%, tree fertilization was 87%, and windbreak wall installation was 91% under-engineered. In addition, it was also confirmed that the watering by sprinkler trucks and chemical spraying were over-designed compared to the actual construction cost at the rates of 118% and 124%, respectively. Due to the specificity of the street trees, the increase in personal expenses and the input cost of equipment, such as road safety controls, were judged to be the main cause of the underestimation of items. Therefore, it is necessary to add items related to street trees and general landscape trees to the landscape maintenance items of the standard of the estimated unit.