Burning fake person for fire prevention heat protection performance test experiment

Firefighters involved in emergency rescue often need a variety of thermal threats such as high temperatures and flames, and operators must wear fire prevention to protect the human body from hot injury 1-2
. Different use environments have different heat sources that cause damage to the human body. The heat transfer method is also different, so fire prevention needs to have a variety of thermal protection properties such as flame retardancy, insulation, integrity 3-4
. In the development of fire prevention, how to accurately test and evaluate the thermal protection performance of clothing is an important basis for promoting fire prevention research and application. At present, China's foreign scholars have studied a lot of research on fire prevention thermal protection performance test methods and predictive models 5-7, although traditional textile flame retardant experiments and TPP experiments can evaluate thermal protection performance of fabrics, but they cannot reflect clothing and clothing. It is supported as an overall fire prevention performance and the degree of protection that can be provided by the install, because it ignores the cropping, design and other additional features of the clothing production process 8-9
. Objective and comprehensive evaluation of thermal protection clothing should simulate the human body actually wear protective clothing in the fire! 10
. The combustion dummy test method uses a fake person placed on an analog heat flow, combustion time, and flame distribution, and predicts the partial and extent of human skin to achieve dimensions and three-scale burn, thereby assessing the overall thermal protection performance of clothing. . The biggest feature is to quickly and accurately simulate the thermal exchange of the human body and clothing, the environment under the conditions of the flashfire 11. I have been using the combustion fake person in the 1960s, I started using the combustion dummy to carry out various thermal protection equipment, and China's development of the combustion dummy system is late, and has been using vertical burning methods and TPP test methods to evaluate the thermal protection of fabrics. Performance, from a certain extent, the research and development of China's thermal protection suit.
Civil fire service has an important role in national fire safety, and excellent thermal protection is one of its most important features. Based on the combustion dummy system of Donghua University Functional Protection Clothing Research Center - "Donghua Fire People", this paper evaluates the overall thermal protection performance of civil fire prevention, and analyzes other factors such as clothing design and structure other than fabrics. The influence of the heat shrinkage of the clothing surface has the effect of reflecting thermal protection performance, which is designed to explore certain related factors affecting the thermal protection of fire prevention, and provide a basis for the optimization design of fire clothing.
1 Real test
1. The test clothing in this experiment is the 3 sets of the same material for a certain product produced for a certain product. The garment is a long coat, standing,
with a sleeve, and the chest back is designed with reflective tape to facilitate identification, and there is a seat belt to escape. Fire prevention equipment is fragrant 1313, the heat insulating layer adhesive cotton, the TPP value of the fabric combination is 33.8, which is greater than the thermal protection value specified by the industry standard. The finished product specifications of the three sets of fire clothes are shown in Table 1.
1.2 Experimental Method
Test Instrument is the Research Center of Donghua University Functional Protection Clothing Research CenterBurning dummy system "Donghua Fire". The system fully meets the relevant technical indicators of ISO13506,
ASTMF1930 and other combustion dummy system evaluation. The dummy's body size uses China's adult male standards, all-body setting
135 hot flow sensors, covering all parts of the trunk, head, hand, and sufficiency, not only for the evaluation of thermal protection clothing, but also meets the helmet, The need for gloves, fire boots, etc., the need for hot protection equipment assessment; in addition, the combustion dummy also sets joint shoulders, elbow, hip, knee and ankle, etc., and
rotation, slip system, can simulate various humans Posture and activity status 12
.
In the experiment, the combustion fake person wearing firefall is placed in the combustion environment of the laboratory simulation, and exposed a certain period of time, and 135 thermal sensors distributed through the dummy through the test garment to the human body. The heat and temperature of the surfaces are predicted to the case of human burn, and the thermal protection performance of clothing is evaluated. The three sets of fire clothes were shown in Table 2. Before the experiment, the standard deviation controlled within 21 kW / m2 by calibration, the average heat flow reached 84 ± 2 kW / m2 specified by the standard. The real-time change in clothing during combustion is observed by video recording combustion processes. The burning test scene is shown in Figure 1.
In order to quantify the apparent variation of the clothing after combustion, the size of the fire prevention collar, the body, the sleeve, etc. Round seal. There is a mark on the seal, horizontal, left, left, right obliquely 4 directions, measure the length change amount of the mark in each direction after combustion, to obtain the shrinkage ratio of the various directions of the clothing, and the calculation method of the shrinkage α is shown in: α (L-L1) / L × 100% (1): L is the length of the printed printed before the combustion, and the length of the imprint after burning, CM.
2 Results and Discussion
2. 1 Skin Burn Ratio Evaluation Results
The results of the combustion dummy test showed that in the first and 2nd fire clothes, the fake people did not reach the burn level, but Wearing 3 fire clothes, the surface of the dummy has a large extent and scope of burns, and its burns are shown in Figure 2. The total surface area of the fake person is 1.816m2. When wearing 3 clothing, the total burn area ratio of the dummy is 62.6%, of which the three-degree burn area ratio is 28.0%, and the divided area ratio is 34.6%. (Once burns is not included in the burn area statistics). The most severe part of burn is concentrated in hip abdomen, chest back, thigh, calf and head, and arm part burn. In addition, the knee joint covered with the underwear of the foot cover is almost no burns. Comparing the test conditions of 3 sets of clothing, the 3rd fire service burned 6s in the 12-piece fireworks. Whether it is burning time or the flame effect is significantly greater than No. 1 and No. 2 clothing. In addition such large hem flames quickly fled on serverWithin the installation, the flame continues to burn nearly 10s in the inner surface of the clothing relatively poor flame retardant, so that the combustion dummy in the experiment has a large extent to be burn. After the hem of the fire prevention in No. 1 and No. 2 utilizes the provincial road to reduce the opening, the flame did not slam into the fire service inside, and the fire prevention did not have a continuous ignition. Therefore, the opening of the critical part of the garment is reduced, and the flame retardancy of the inner layer material in the clothing is more conducive to improving its thermal protection. In addition, the reflective bonding and melt phenomenon of the clothing chest and the melt phenomenon were observed. Although in TPP testing, the garment meets the relevant requirements, but the performance of the reflective belt is not reflected. This also shows that the thermal protection of clothing is not only related to the performance of fabrics, but also the use of clothing's style structural design, clothing accessories and accessories such as buttons, magic stickers, reflective belts, and clothing use environments are equally important to protective clothing.
2.2 The heat shrinkage of the clothing
No. 3 clothing combustion experiments have a significant contraction, and there is a lot of holes, and the insulation layer is exposed. Due to the severe damage after the fire in fire prevention, the size of the critical part of the clothing after combustion experiment was not accurately measured, and thus the shrinkage of the garment surface after combustion was analyzed, mainly for 1 and 2 fire service. According to Table 3, the shrinkage amount of each portion of the burning body is generally larger than the contraction of the portion of the sleeve after 1 and 2 clothing. The largest portion of the contracted volume is the hip wide, with an average of 11 cm, followed by a lumbar width, and the shrinkage amount is gradually reduced from the buttocks to the chest direction. In addition, the total length of the total length of the shaded body is also large, reaching 7 cm. The shrinkage of the periphery of the top 1 clothing is taken to 8cm, which is obviously greater than the surplus of the periphery of the 2nd garment, which may be equipped with the fireproof mask with the experiment. The rigging of the neck should be closely fitted with the outer wall of the mask when wearing 1 fire service, thereby increasing the area of the combustion experiment neutralizing the contacted flame. The variance analysis of the key part of the 1st and 2 clothing, found that there is no significant difference in the difference, Pu003e 0.05.1 and No. 2 clothing for materials, styles and size exactly the same two-piece clothing, The difference in shrinkage of clothing does not significantly indicates that the distribution of combustion heat sources is consistent, and the experimental results are stable and repeatable.
According to the formula (1), each seal on the garment is calculated in the shrinkage, the horizontal, left obvene, right obliquely 4 directions, then taking the average value, obtain a shrinkage of the corresponding sensor portion on the clothing, which distributes Figure 3 shows. It can be seen that the front shrinkage ratio is more than 5% of the back, and the front severity variable portion is in the back surface, the front main deformation area is 3cm on the hip line, the main deformation area of the back is the chest line. About 3cm under the hip line, which may be related to the distribution of the air layer under the shot and the amount of heat flow obtained at the site. The inverse two sides of the clothing are the largest contraction of the bantles, and the shrinkage ratio is between 15% to 20%. Take the shape of the seal in the galvan of the left film of the clothing into an example to draw the shape of the seal in all directions.Variable rate, as shown in Table 4. According to the statistical analysis of SPSS16.0, there is no significant difference in the same seal site in the horizontal, vertical and oblique deformation rate, and Pu003e 0.05. Note For this experimental costume, the same
portion is more uniform in different directions.
In summary, in the combustion dummy test, the main deformation of fire prevention in 1 and 2 is the chest to the lapse area, where the most severe part is a bistem. The deformation not only affects the structure of the clothing and the integrity of the clothing, but also reduces the protection of the human body to the human body. When the costume continues to expose in the flame, the probability of burns in the prosthetic chest to the knee area will increase significantly, so the shrinkage of the garment surface can also affect the thermal protection performance of the clothing to a certain extent.

Combination This paper uses the combustion fake person to evaluate the overall thermal protection performance of civil fire prevention. The results show that the thermal protection performance of clothing depends not only on the thermal protection performance of the fabric, but also closely related to the style of clothing, the performance of the accessories and the use of clothing. In the 3rd clothing, the total burn area of the dummy reached 62.6%, and the part of the three-degree burn and the three-degree burn were concentrated in the bistem, the chest back and the thigh. After the 1st and 2nd clothing is collected, the flame does not turn into the clothing to cause sustained burning. Reduce the critical parts of the garment, more beneficial to improve the thermal protection performance of clothing.
Using the combustion fake person can quantify the overall thermal protection performance of the garment, predict the partial and extent of the human skin by the dimensions and three-degree burn, the contraction form of the garment surface can also reflect the thermal protection of the clothing. Although the surface of the dummy is not predicted in the No. 1 and No. 2 clothing test, it has been burn, but the chest to the knee area exhibits a large contraction shape, and the casifer even reaches 15% to 20%. Exploring the heat shrinkage mechanism of clothing surface in high temperature and its impact on thermal protection performance, it is of great significance for clothing thermal protection performance.



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