Comparison of fire extinguishing performance of four halon substitutes and Halon 1301

2021 ◽  
pp. 073490412110301
Author(s):  
Yawei Wang ◽  
Gaowan Zou ◽  
Conglin Liu ◽  
Y Gao
Keyword(s):  
Dilution Effect ◽  
Pool Fire ◽  
Design Standards ◽  
Ignition Probability ◽  
Fire Extinguishing ◽  
Halon 1301 ◽  
Efficient Alternative ◽  
Oil Pool ◽  
The Difference ◽  
Effect Of Oxygen

The Halon 1301 fixed gas fire extinguishing system used in ship engine rooms has been banned from production all over the world, because halon destroys the ozone layer. Therefore, it is necessary to find an environmentally friendly, compatible and efficient alternative firefighting system. In this study, we performed fire extinguishing tests in an ISO9705 standard room for four alternative fire extinguishing agents, as well as Halon 1301. The fire extinguishing efficiency of each agent was determined based on its cooling effect, dilution effect of oxygen concentration, the extinguishing time of the oil pool fire and the re-ignition probability of the wood stack. The test results provide data support for the selection of alternatives of Halon 1301 from the aspect of fire extinguishing efficiency. Among these results, Novec 1230 had the best ability to put out the oil pool fire, and HFC-227ea suppressed the wood stack fire the best. The difference between the cooling ability of each fire extinguishing agent was small, and the inert gas (IG-541) displayed the best ability to dilute oxygen. Hot aerosol required the longest time to extinguish fire. Consequently, under the existing design standards, HFC-227ea had the better firefighting efficiency, more suitable to replace Halon 1301.

Experimental and Numerical Study on the Suppression of Pool Fire with Water Mist

2013 ◽  
Vol 790 ◽  
pp. 686-689
Author(s):  
Chen Jian ◽  
Xu Yan Ying ◽  
Wang Yan Sheng
Keyword(s):  
Systems Engineering ◽  
Numerical Study ◽  
Fire Suppression ◽  
Inhibitory Effect ◽  
Water Mist ◽  
Pool Fire ◽  
Optimized Design ◽  
Operating Pressure ◽  
Fire Extinguishing ◽  
Oil Pool

The objective of this work is to investigate the diesel analog pool fire with water mist .For this purpose, a series of water mist fire suppression experiment are carried out by changing the nozzle operating pressure, the source of fire power, opening and closing the exhaust fan to analyze the inhibitory effect of water mist to oil pool fire in the enclosed compartment of 5.0m × 5.0m × 3.0m. The results shows that extinguishing efficiency first increases and then decreases when the nozzle operating pressure increases from 8MPa to 12MPa, reaching the highest efficiency at 10MPa; increasing the power of the source of fire, the burning speed increases and the water mist fire extinguishing efficiency decreases; fresh oxygen coming in when smoke exhaust fan is turned on and water mist fire suppression efficiency decreases. Using FDS to simulate the water mist extinguishing oil pool fire, the predict temperature field and extinguishing time are basically consistent with the experimental results. In the actual applications of water mist fire suppression systems engineering, we can use the FDS field simulation methods to predict the characteristic parameters variation of the fire fighting fire temperature and component concentration, which is significant to the fire extinguishing system optimized design.

scholarly journals Effects of Discharge Area and Atomizing Gas Type in Full Cone Twin-Fluid Atomizer on Extinguishing Performance of Heptane Pool Fire under Two Heat Release Rate Conditions in an Enclosed Chamber

2021 ◽  
Vol 11 (7) ◽  
pp. 3247
Author(s):  
Dong Hwan Kim ◽  
Chi Young Lee ◽  
Chang Bo Oh
Keyword(s):  
Heat Release ◽  
Flow Rate ◽  
Heat Release Rate ◽  
Release Rate ◽  
Water Mist ◽  
Pool Fire ◽  
Sauter Mean Diameter ◽  
Discharge Area ◽  
Fire Extinguishing ◽  
Enclosed Chamber

In this study, the effects of discharge area and atomizing gas type in a twin-fluid atomizer on heptane pool fire-extinguishing performance were investigated under the heat release rate conditions of 1.17 and 5.23 kW in an enclosed chamber. Large and small full cone twin-fluid atomizers were prepared. Nitrogen and air were used as atomizing gases. With respect to the droplet size of water mist, as the water and air flow rates decreased and increased, respectively, the Sauter mean diameter (SMD) of the water mist decreased. The SMD of large and small atomizers were in the range of approximately 12–60 and 12–49 μm, respectively. With respect to the discharge area effect, the small atomizer exhibited a shorter extinguishing time, lower peak surface temperature, and higher minimum oxygen concentration than the large atomizer. Furthermore, it was observed that the effect of the discharge area on fire-extinguishing performance is dominant under certain flow rate conditions. With respect to the atomizing gas type effect, nitrogen and air appeared to exhibit nearly similar extinguishing times, peak surface temperatures, and minimum oxygen concentrations under most flow rate conditions. Based on the present and previous studies, it was revealed that the effect of atomizing gas type on fire-extinguishing performance is dependent on the relative positions of the discharged flow and fire source.

scholarly journals The enzymes of B. coli communis . Part V.—(a) anaerobic growth followed by anaerobic and aerobic fermentation. (b) the effects of aeration during the fermentation

1921 ◽  
Vol 92 (644) ◽  
pp. 135-150
Keyword(s):  
Anaerobic Growth ◽  
Aerobic Growth ◽  
Aerobic Fermentation ◽  
The Subject ◽  
The Difference ◽  
Effect Of Oxygen ◽  
Present Section ◽  
Ferment Glucose

In the present communications the effect of oxygen upon the fermentation of glucose and upon the growth of the bacteria, in so far as this affects fermentation, is considered. To this end the organisms have been grown both aerobically and anaerobically, and subsequently made to ferment glucose, both aerobically and anaerobically, with the object of comparing the products of decomposition in the two cases. There are clearly two problems : firstly, the effect of exposure to oxygen during growth upon the subsequent fermentation, whether aerobic or anaerobic, and, secondly, the effect of oxygen admitted during the fermentation. The first question relates to the part played by oxygen in the formation of enzymes, the second to the part played by oxygen in their action on carbohydrates. The first question is considered, though in but a preliminary way, in Section A, the second, more fully, in Section B. Section A. Object of the Experiments . Two results were aimed at in these experiments. Firstly, to compare the products of fermentation of glucose anaerobically, after anaerobic growth, with the products of fermentation anaerobically after previous growth aerobically. And, secondly, to obtain information as to the effect of introducing oxygen during the fermentation itself. This latter consideration, however, though brought to notice by these experiments, is considered only incidentally here because it forms the subject of Section B. In the present section we wish to direct attention particularly to those differences which exist between the fermentation after anaerobic and aerobic growth, not upon the effect of aeration during the fermentation. To point out the difference which previous growth aerobically or anaerobically has made, several analyses from previous experiments are included in Table IV side by side with the completely anaerobic experiments of Tables I, II, and III.

scholarly journals Comprehensive Assimilation of Fire Suppression Modeling and Simulation of Radiant Fire by Water and Its Synergistic Effects with Carbon Dioxide

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5850
Author(s):  
Hassan Raza Shah ◽  
Kun Wang ◽  
Xu Qing Lang ◽  
Jing Wu Wang ◽  
Jing Jun Wang ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Synergistic Effects ◽  
Fire Suppression ◽  
Water Mist ◽  
Pool Fire ◽  
Water Suppression ◽  
Water Droplets ◽  
Film Forming ◽  
The Difference ◽  
Suppression Effects

Recently, water has been employed as a supportive agent for the preparation of multiple suppressing agents including aqueous film forming foams (AFFF), which is combined with different kinds of gases for its various applications. In this study, the water mist is chosen for the gas-suppressing agent such as carbon dioxide. Our work investigated the suppression effects of water droplets on the n-heptane pool fire, and its mixture with carbon dioxide, respectively. The size and frequency of droplets with their effect on temperature and suppression was compared to observe the difference in the suppression. Initially, it was found that the droplets having a larger droplet size were found to be more efficient as compared to the smaller droplets with respect to the heat release rate, temperature, and radiation. Afterwards, a mixture of water droplets and carbon dioxide was simultaneously discharged to compare the difference between these two suppressing agents. It was found that the synergistic effect of the mixture has higher advantages over the use of only water suppression. It helps reduce the hot gases that surround the pool fire and allows the water mist to travel efficiently towards the fuel. Both suppression mechanisms were set to similar initial parameters that lead to different outcomes.

Experimental study on burning behavior of crude oil pool fire in annular ice cavities

Fuel ◽  
2018 ◽  
Vol 234 ◽  
pp. 464-472 ◽  
Author(s):  
Depeng Kong ◽  
Zhen Zhang ◽  
Ping Ping ◽  
Guoming Chen ◽  
Xu He ◽  
...  
Keyword(s):  
Experimental Study ◽  
Crude Oil ◽  
Pool Fire ◽  
Burning Behavior ◽  
Oil Pool

Effects of the initial fuel temperature on burning behavior of crude oil pool fire in ice cavities

2018 ◽  
Vol 31 (5) ◽  
pp. 436-449 ◽  
Author(s):  
Depeng Kong ◽  
Zhen Zhang ◽  
Ping Ping ◽  
Xu He ◽  
Hanbing Yang
Keyword(s):  
Crude Oil ◽  
Pool Fire ◽  
Fuel Temperature ◽  
Burning Behavior ◽  
Initial Fuel ◽  
Oil Pool

Research on the Combustion Characteristics of Small-Scaled Ethanol Pool Fire of Different Aspect Ratios

2011 ◽  
Vol 347-353 ◽  
pp. 1161-1165
Author(s):  
Cui Peng Kuang ◽  
Yuan Zhou Li ◽  
Shi Zhu ◽  
Shao Hua Mao
Keyword(s):  
Temperature Distribution ◽  
Aspect Ratio ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
Pool Fire ◽  
Aspect Ratios ◽  
Fire Experiment ◽  
The Difference ◽  
Experimental Values ◽  
Centerline Temperature

Four groups of small-scaled ethanol pool fire experiment with different aspect-ratio(s) is undertaken, to gauge the mass loss rate of fuel as well as the plume centerline temperature distribution. Comparison of plume centerline temperature is made between the theoretical values estimated by Heskestad plume model and experimental results, which indicates that: with the increasing of s, the difference between theoretical values and experimental values tend to grow greater; and when s≈1, theoretical values and experimental values cohere well.

Analyte Transport Studies of Aqueous Solutions and Slurry Samples Using Electrothermal Vaporization ICP-MS

1995 ◽  
Vol 49 (10) ◽  
pp. 1403-1410 ◽  
Author(s):  
R. W. Fonseca ◽  
N. J. Miller-Ihli
Keyword(s):  
Aqueous Solutions ◽  
Inductively Coupled Plasma ◽  
Oyster Tissue ◽  
Electrothermal Vaporization ◽  
Experimental Conditions ◽  
Carbon Particles ◽  
Icp Ms ◽  
The Difference ◽  
Effect Of Oxygen ◽  
Analyte Transport

Analyte transport of both aqueous solutions and slurry samples was studied with the use of ultrasonic slurry sampling electrothermal vaporization inductively coupled plasma mass spectrometry (USS-ETV-ICP-MS). The elements studied included V, Mn, Ni, Cu, and Pb, and the materials analyzed included NIST SRM 1548 Total Diet, SRM 1632a Coal, SRM 1566a Oyster Tissue, and NRCC LUTS-1 Lobster Hepatopancreas. The effect of microgram amounts of Pd as well as the effect of oxygen ashing on analyte transport were studied. Slurry samples were found to have better analyte transport in comparison to aqueous solutions when no physical carriers were added. Under these experimental conditions, the determined slurry concentrations were apparently high when quantified with the use of external calibration. Microgram amounts of Pd were used to investigate whether it was possible to reduce the difference in analyte transport between slurry samples and aqueous standards. The use of microgram amounts of Pd resulted in signal intensity suppression. Such a signal reduction could be related to the presence of space charge effects or losses of analyte due to condensation of the physical carrier together with the analyte on different parts of the ETV cell or the transfer line. On the other hand, quantitation for slurry samples was improved by the use of Pd as a physical carrier. Pd by itself was not completely effective for samples with high carbon content; therefore the effect of oxygen ashing combined with Pd was studied. An enhancement of signal intensities was observed when oxygen ashing was used, as well as a shift in the carbon signal to earlier times. In this case, signal enhancement was associated with an improvement in analyte transport caused by an increased number of carbon particles leaving the furnace at the same time as the analytes studied. With oxygen ashing, slurry samples behaved more similarly to aqueous solutions, facilitating quantitation with aqueous standards.

A study of the probability distribution of pool fire extinguishing times using water mist

2015 ◽  
Vol 93 ◽  
pp. 240-248 ◽  
Author(s):  
Tianshui Liang ◽  
Mengjie Liu ◽  
Zhonglin Liu ◽  
Wei Zhong ◽  
Xiukun Xiao ◽  
...  
Keyword(s):  
Probability Distribution ◽  
Water Mist ◽  
Pool Fire ◽  
Fire Extinguishing
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