• International journal of advanced smart convergence
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• v.10 no.3
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• pp.232-244
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• 2021

This study analyzed the changes in carbon monoxide, carbon dioxide, oxygen and visual distance by presence of sprinkler heads and their types in the event of a fire in an indoor gymnasium. Based on carbon monoxide and visual distance that affects human bodies enormously, first, if there is no sprinkler head, carbon monoxide will reach 0.4% within five seconds and visual distance rapidly shrank within five seconds. Seconds, in the event of standard sprinkler heads, carbon monoxide gradually increased from 30 seconds onwards and visual distance rapidly shrank after five seconds. Second, Third, if there are special sprinkler heads, carbon monoxide fluctuated after opening the head and visual distance became 5m or below from 15 seconds. Finally, in the event of early response sprinkler heads, carbon monoxide fluctuated up and down at 3 seconds due to falling water drops. Visual distance shrank up to 5m or below at 6 seconds. In the future, time for operation of each sprinkler head shall be analyzed.

• Journal of the Korean Society of Safety
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• v.16 no.2
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• pp.13-21
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• 2001

The effect of water spray for the fire sprinkler depends on droples distribution over maximum possible floor area. The present study are carried out for the characteristics of water spray and droplets experimentally and numerically km two fire sprinkler heads which are CHM head and CHl heal CHl head is self-production and CHl head is widely used up to date. As the result of using CHM head, water spray and droplets are distributed over large area because CHM head has smooth surface and non-flamed shape. When the pressure of fire sprinkler head is low, SMD(sauter mean diameter) is large and when the pressure of fire sprinkler head is high, SMD is small.

• International journal of advanced smart convergence
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• v.10 no.4
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• pp.117-123
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• 2021

This study aims to analyze working hours of sprinkler heads when a fire occurs at an indoor gymnasium while sprinkler heads are installed in division of standard response type, special response type, and earlier response type. The fire scenario was designed under the assumption that the fire started from overheating of a heater in the indoor gymnasium has transferred on to a couch to spread. The analysis on the operation time of the standard response type sprinkler head, the special response type sprinkler head and the early response sprinkler head was conducted. The result showed that, in case of fire in a gymnasium, the time for opening of the heat sensor due to the heat from the fire varies by the type of the sprinkler head. When a special response type sprinkler is installed, it worked below the assessment standards. When an early response sprinkler head is installed, it worked appropriately according to assessment standards. Based on the results, we found that sprinkler heads will work properly when installed according to design relevant to laws and regulations. This means that there is a limit in installation of sprinkler heads based on the existing law-based design as for indoor gymnasiums. Again, we conclude that if sprinkler heads are installed based on design made through laws and regulations, more time will be needed for operation, making it highly likely to fail to stop a fire at an earlier point of time.

• Journal of the Korean Society of Safety
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• v.33 no.2
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• pp.32-38
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• 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 ILASS-Korea
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• v.28 no.2
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• pp.97-104
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• 2023

A sprinkler is a fire suppression system that extinguishes combustible materials in the early stages of a fire, creating a spray. However, spray formation method of the sprinkler can result in an uneven distribution of water spray on the surface of combustible materials. It is necessary to ensure a consistent water flux density regardless of the spray direction and angle. In this study, the water flux distribution was analyzed for the various types of sprinkler head: circular, flush, pendent, and upright types. All sprinkler heads have a K-factor of 80 LPM/(0.1MPa)^0.5. In this study, water collection cubes were used to examine the water flux distribution. The upright type sprinkler head showed a low standard deviation in total sprayed area, indicating a high level of uniformity. The upright type head showed the lowest standard deviation in the radial direction, and also showed the lowest standard deviation in the azimuthal direction. Upright sprinkler head has no obstructing structure along the path of droplets after they are generated. For this reason, upright sprinkler head showed the most uniform water flux distribution on the floor.

• Fire Science and Engineering
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• v.9 no.1
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• pp.20-29
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• 1995

The sprinkler head is a component of the sprinkler system intended to discharge water for automatic detection and extinguishment of fires. On this study, thermal characteristic values affecting the sensitivity of the fusible alloy type sprinkler head were obtained and analyzed under heated air stream condition which had constant temperature and velocity. The experiment was carried out under the forced convection condition with both the conductive heat loss considered and neglected. The thermal characteristic values of the sprinkler head were obtained in accordance with the material and shape of the heat responsive element and the conditions of the main body.

• Fire Science and Engineering
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• v.31 no.3
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• pp.54-62
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• 2017

The aim of this study is to find out the water spray features of in-rack sprinklers for rack storage. This study conducted cold water flow test, measurement of spray angle and densities by angles for sprinkler head manufactured by a Korean company and a U.S. company. Korean sprinkler head had a wide angle of water spary. The water spray angle of a U.S. sprinkler head was narrow compared to the Korean sprinkler. In comparison of the Korean head with U.S. head of the same K80, the Korean head can send water to parts that are difficult to directly spray, but the spraying density by angle was low. U.S. head can send more water than Korean head at a narrow angle. In conclusion, for flammable materials placed in two or more rows in a rack storage, a zigzag arrangement with face sprinklers will be effective.

• Fire Science and Engineering
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• v.34 no.4
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• pp.45-51
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• 2020

The aim of this study is to investigate the gas temperature and velocity during sprinkler activation considering the fire growth scenario based on the thermal response model of the sprinkler. The fire source is assumed to have time square fire growth scenarios with a maximum heat release rate of 3 MW. Eight types of standard and fast-response sprinkler heads with an operating temperature range of 65-105 ℃ and a response time index range of 25-171 m^1/2s^1/2 were adopted. The temperature difference between the gas stream and the sensing element of the sprinkler head decreased as the fire growth slowed down, and the RTI value decreased. The overall gas temperature and velocity conditions predicted using the FDS model at sprinkler activation were in reasonable agreement with those of standard test conditions of the sprinkler head response. However, the sprinkler head could be activated at lower limits of gas temperature and velocity under the current test conditions for a slowly growing fire scenario.

• Journal of the Korean Society of Safety
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• v.13 no.4
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• pp.59-70
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• 1998

In this study, response time index(RTI) of standard and quick response type sprinkler head are measured and compared through ramp and plunge test in heated wind tunnel. Also discharge rate and water distribution, actual delivered density(ADD), fire test with wood cribs are performed to compare the fire suppression capability and the operation time and temperature between standard and quick response type sprinkler head.

• Fire Science and Engineering
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• v.7 no.2
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• pp.3-12
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• 1993

The closed type sprinkler head is a component of sprinkler system for fire protection. The purpose of this study is to inverstigate the influence factors of the responsiveness of the head by heated wind tunnel experiment. As the result of this study, it was found that response time index and conduction parameter showed the same characteristic quantitative changes to head types and test methods.