Application of Combustion Dooler Test System in Field of Clothing Flame Retard

The combustion dummy test system guarantees the safety important test method of the staff under testing fire and thermal radiation, and China mainly uses the flame retardant protection performance of the textile vertical combustion test method and the limit oxygen index method. . Both of these methods can only explain whether the clothing fabric flame retardant is not possible to explain the high temperature and high thermal resistance of the garment to the flame or arc. The combustion dummy test system uses the dummy to test the limit of the survival environment under various harsh conditions in the simulated test environment.

First, the composition of the combustion dummy test system and the design principle

The system is mainly generated by the combustion dummy, data acquisition device, flame generation and Control device, skin heat transfer model and burn evaluation model and system centralized control and application software platform. The design principle is by simulating the thermal exposure process in the burning flame, testing the surface temperature of the dummy, is estimated that the skin can cause the skin, three-degree burns and total burns area percentage, the larger the burn area, the apparel The worse the flame retardant protection performance, the system test principle.

Second, the combustion dummy test system combustion dummy research

Search for foreign abroad, use non-metallic materials to make a combustion dummy body, the flame of the clothing test The duration is generally 4 s. The surface of the dummy may require a combustion flame of up to 300 ° C, so the dummy's body material must have good thermal stability under the short-time combustion flame of 300 ° C, to withstand the harsh fire The sensor of the dummy's surface is adjacent to the reaction of the burning flame should be proximate to the human skin; the data acquisition processing device quickly captures the dummy surface sensor data. 1, the dummy body According to the above design requirements, polyimide, the highest temperature resistance, mechanical properties, dielectric properties, and corrosion resistance, the best resistance to high temperature resistance. Examples of the combustion dummy body body material, according to the appearance characteristics of the prosthetic model,
Made a dummy body model according to the following process: synthetic polyimide → cured resin material → produce each decayment section of the human body and high temperature molding → vacuum curing → Surface processing.
2, the dummy surface heat sensor
The effect of the skin surface heat sensor is to sense the heat of the skin's skin in the fire environment, which predicts the degree of burns that the skin may occur. The thermal sensors used abroad mainly include TPP copper sheet heat flow sensors, adiabatic copper sheet sensors and embedded thermocouple sensors. Among these three sensors, the heatstick copper sheet sensor is the most reliable thermal sensor. Experiments show that the heat-insulating copper sheet sensor is similar to the TPP copper sheet heat flow sensor, the reading is stable, the reaction is rapid, the range is wide, and the sensor is small, and the space and quality are more than TPP copper sheet.Many of the accounts. In a high heat environment, the average reaction rate of the embedded thermocouple sensor is slower than the adiabatic copper sheet sensor. To this end, the topic group developed a thermally insulating copper plate sensor having a diameter of 1 cm and a thickness of 0.16 cm. The brazing process is used to connect the copper sheet to a K-type thermocouple of 0.2 mm with a wire diameter, and the measurement accuracy reaches 0.2 ° C. 3, sensor layout
Comprehensive considers of dummy area, data acquisition, burn evaluation calculation and other factors, 120 adiabatic copper plate sensors in the surface of the dummy. When installing the sensor, use the milling cutter to bore in diameter and depth of the copper sheet, ensuring that the sensor surface and the surroundings are closely fit to the dummy body, and the distribution of the sensor is uniform.

Third, Burning Dummy Test System Data Acquisition Device

The data acquisition device mainly completes the acquisition processing of 120 thermocouple temperature signals on the surface of the dummy. To ensure the synchronization and high speed acquisition of the 120-channel temperature signal, 20 data acquisition processing units are designed, each data acquisition processing unit consists of master CPU, AD acquisition circuit, real-time clock circuit, power supply circuit, thermocouple temperature sensor, and CAN bus communication. Partial composition, implementing the synchronous acquisition of the 6-way false surface temperature signal; uses the CAN bus communication technology to connect 20 data acquisition processing boards, by the PC via the PCI? 1680U high-speed CAN communication card to 20 data acquisition processing units Collect parameters and start collecting commands to achieve synchronous high speed acquisition of 120-road vacant surface temperature signals.

4, Flame Generation and Control Device
Flame Generation and Control Device mainly generate combustion flames for clothing flame retardant protection performance test requirements. Includes 3 parts of the use of fuel, gas delivery pipe design, and combustors.

1, the fuel selection

Comparative analysis of conventional clean, combustible gas physicochemical properties, widely available propane, to form water vapor and carbon dioxide after combustion, is an environmentally friendly fuel, and a high heat of combustion values, a lower boiling point, security is good, more suitable for use in the colder northern laboratory test so that the fuel system is selected as propane.
2, gas pipeline design The main gas delivery conduit for delivering vaporized under reduced pressure to a burner propane in the liquid storage cylinders. The foreign similar technical requirements, the control device generating the flame must burn in a 5 s time gas pipeline pressure fluctuation is less than 10%, the maximum heat flux of 84 kW / m2, the design requirements to achieve this, using only difficult to achieve automatic control technology and, therefore, the buffer tank multi-block design, and take multiple measures in the design of the gas pipeline, with the pipeline pressure and flow monitoring, the gas pipeline has quickly add capacity and adequate gas transmission capacity. propane gas tank pressure is typically 0.5 ~ 2.5 MPa, in order to ensure safety, the gas pressure before the burner is set to about 0.1 MPa, so it is necessary to step down step by step by step by air delivery. To this end, design three-stage pressure regulation and two-stage large-capacity gas storage tank buffer circuit, the working pressure of the three-stage gas conveying pipe is set to 0.6 MPa, 0.3 MPa and 0.1 MPa, respectively.
A pressure transmitter, electric regulator, safety valve, solenoid valve, and shut-off valve are matched on the three-stage gas delivery pipe, and the monitoring, adjustment and switching control of pipe gas pressure is achieved. The flow rate is equipped with the gas flow rate in the third stage pipe for metering the gas flow in the combustion process, and is equipped with a safety check valve on the pipe connected to the burner to prevent turf when the flame is turned off.
3, combustor design
designed 12 ring firefire burners for generating a combustion flame having a maximum heat flow of 84 kW / m2, 12 ring fire burners were simultaneously ignited at the same time, flame A combustion cylinder to swallow the dummy's body from a fake person. At the same time, the ring fuel burner fixture is developed, and the flame size, shape, and strength adjustment are achieved by adjusting the height of the burner and the distance to the dummy.

Five, the application software development

The application software platform is the nerve center of the entire system, mainly by data acquisition module, monitoring and control module, matrix Computer module, burns predictive analysis processing module and system resource management module, realizing the acquisition processing, combustion process, and all instrument equipment of the 120-way dummy temperature signal, calculating the degree of skin burn ω value, the percentage of two-degree burn area, The percentage of three-degree burn area and the total burn area percentage, assess the overall flame retardant protection performance of clothing. The composition framework of the application software platform.

Sixth, the combustion dummy test system is blended with cotton, aramid / carbon fiber blended by this system to a research firm, Nitrite / cotton blending flame retardant overalls, waterproof flame retardant, three-layer film-resistant high-temperature fire clothing and flame retardant protection performance of single-layer coil fire clothes, quantitative testing and comparative analysis, 84 kW / m2 Under the combustion flame, 4 S's clothing flame retardant protection performance test, test results. As can be seen from Table 1, the flame retardant protective properties of cotton flame retardant overalls with 416 g / m2 and a flame retardant protective protection of a nitrile / pecton / cotton blended waterproof flame retardant in 319 g / m2 Performance, the flame retardant protective properties of the three-layer film-resistant anti-fire clothing are better than the single-layer structure of the same fabric. Although the flame retardant protection of aramid fabrics is very good, the fabric is thinner, and the flame retardant protection performance of clothing is still relatively thick and the flame retardant protection of cotton and nitrile / pecton / cotton clothing. The above test trials show that the system can test the flame retardation of different materials and structural clothing better test.Protection performance.