CN208043762U - The experimental provision of cable fire characteristic under a kind of measurement oxygen-enriched environment - Google Patents

Abstract

The utility model relates to an experimental device for measuring the combustion characteristics of cables in an oxygen-enriched environment, comprising a housing, an air intake system, an exhaust system, a cable support system, an ignition system, a combustion parameter testing system, an oxygen monitoring system, and a data acquisition system. The air intake system is installed at the bottom of the shell, the exhaust system is installed at the top of the shell, the cable support system is fixed on the shell, and the experimental materials are placed through the crucible. The ignition system is arranged on the inner wall of the crucible to heat the material. The combustion parameter test system includes radiation heat flow meter, thermocouple and flue gas composition sensor. The oxygen monitoring system controls the oxygen sensor by the steering gear to monitor the oxygen concentration near the crucible. Control instruction. The utility model has simple structure and strong operability, and provides a simple and feasible experimental device for studying the combustion characteristics of cables in an oxygen-enriched environment.

Description

An experimental device for measuring the combustion characteristics of cables in an oxygen-enriched environment

technical field

The utility model relates to the field of fire combustion research, in particular to an experimental device for measuring the combustion characteristics of cables in an oxygen-enriched environment.

Background technique

With the development of the economy and the improvement of living standards, the level of electrification in production and life has increased, and electrical fire accidents have also increased. According to the "China Fire Statistical Yearbook", in the past ten years, electrical fires have ranked first among all fire causes, and electrical fires caused by wires and cables account for more than 50% of the annual electrical fires, ranking first among all types of fires, causing casualties and Property damage was also the most serious.

According to Xu Xiaonan et al.'s "Wire and Cable Fire and Flame Retardant Treatment", the insulation and sheath materials of most wires and cables are composed of various polymers, such as polyvinyl chloride (PVC), ethylene copolymer (PE), ethylene-acetic acid Copolymers such as ethylene copolymer (EVA), polypropylene (PP), and chloroprene have hazards such as large smoke generation, violent combustion, and easy generation of toxic gases in actual fires. Therefore, it is urgent to carry out research on the combustion characteristics of cables to develop more flame-retardant and safer wires and cables.

To study the combustion characteristics of cables under normal circumstances, instruments such as cone calorimeter and thermogravimetric analysis can be used. These research methods and experimental equipment are relatively mature. However, in some special environments, such as an oxygen-enriched environment due to the leakage of oxygen cylinders, the fire hazard, combustion characteristics and composition of smoke products of cables will be significantly different from those in normal environments. Oxygen cylinders are widely used in aerospace, medical, shipbuilding, industrial welding and other places. Every year there are several fire accidents caused by oxygen leakage. However, for the research on the combustion characteristics of cable fires in an oxygen-enriched environment, there are few relevant literatures at home and abroad, and the relevant experimental devices are also very scarce.

Utility model content

The utility model proposes an experimental device for measuring the combustion characteristics of cables in an oxygen-enriched environment, which has the advantages of simple device, strong operability, and good repeatability of experimental results.

In order to achieve the above object, the utility model adopts the following technical solutions:

An experimental device for measuring the combustion characteristics of cables in an oxygen-enriched environment, including a housing, an air intake system, an exhaust system, a cable support system, an ignition system, a combustion parameter testing system, an oxygen monitoring system, and a data acquisition system.

The shell is composed of cylindrical non-combustible material, the bottom and surrounding are sealed, and the top is open;

The intake system is divided into an oxygen intake system and a nitrogen intake system. Each system is composed of a gas cylinder, an intake pipe, and a flow controller. Installed in the middle of the intake pipe;

The exhaust system is composed of a smoke exhaust fan and an exhaust pipe. The smoke exhaust fan is installed inside the exhaust pipe, and the exhaust pipe is installed outside the shell, which is sealed and connected with the top opening of the shell; the cable support system includes a bracket, a crucible, and one end of the bracket It is fixed on the shell, and the other end of the bracket has a tray in the center of the shell, and the crucible is placed on the tray, and the cables to be tested are cut into sections and placed in the crucible;

The ignition system is composed of switches, wires, high-temperature ceramic tubes, and heating wires. The heating wires are arranged at the bottom of the crucible. The wires extend into the inside of the shell from the opening on the side wall of the shell, and the wires pass through the high-temperature ceramic tubes inside the shell;

Combustion parameter test system is composed of thermocouple beam, gas sensor and radiant heat flow meter. The thermocouple beam is arranged above the crucible. In the flue gas plume area above the flame, the gas sensor can measure gases in the combustion flue gas such as carbon dioxide, carbon monoxide, and hydrogen chloride;

The radiant heat flow meter is fixed on the inner wall of the shell, and is in a horizontal position with the cable flame, and the radiation receiving surface of the radiant heat flow meter faces the flame;

The oxygen monitoring system consists of a steering gear, a steering arm, and an oxygen sensor. The steering arm is connected to the steering gear and the oxygen sensor. The steering gear is fixed on the housing, and the steering gear control board is outside the housing. The steering gear control board and the steering gear pass through the control line. Connected, the steering gear can control the horizontal rotation of the steering arm, so that the oxygen sensor can move between the position close to the crucible and the area close to the inner wall of the shell;

The data acquisition system consists of a computer, a multi-function data acquisition card, and a digital-to-analog conversion module. The analog input terminal of the multi-function data acquisition card is connected to modules required for measurement such as thermocouples, various gas sensors, and radiant heat flow meters, and the output terminal is connected to the computer. , the computer is connected to the flow controller, steering gear control signal line, ignition signal control line, fan and other devices through the digital-to-analog conversion module.

It can be seen from the above that the air intake system of the utility model is installed at the bottom of the shell, and the oxygen and nitrogen intake volume is adjusted by the flow controller. The exhaust system is installed on the top of the shell, and the air volume is adjusted by the fan. The cable support system is fixed on the shell. The experimental materials are placed in full bloom. The ignition system consists of electric heating wires arranged on the inner wall of the crucible to heat the materials. The combustion parameter test system includes a radiant heat flow meter fixed on the inner wall of the shell, a thermocouple above the flame and a smoke composition sensor. The oxygen monitoring system consists of a steering gear The oxygen sensor connected to the steering arm is controlled to monitor the oxygen concentration near the crucible. The data acquisition system uses a computer, a multi-function data acquisition card, and an analog-to-digital conversion module to collect data from each sensor and issue control commands.

The beneficial effects of the utility model are:

1. The device of this utility model can conveniently adjust the oxygen content in the cabin inside the shell through the flow controller, create an oxygen-enriched environment, and provide a simple and feasible experimental device for studying the combustion characteristics of materials in an oxygen-enriched environment.

2. The device of this utility model adopts the ignition method of arranging electric heating wires in the crucible, which avoids the influence of ignition methods such as electric spark ignition and open flame ignition on the test results of combustion characteristics. The ignition structure is simple, the operation is convenient, and the ignition efficiency and combustion test results are improved. accuracy.

3. The device of the utility model integrates the combustion flame temperature, flame radiation, and smoke composition parameters of the cable material, and can conveniently obtain the combustion characteristics of the cable material in an oxygen-enriched environment.

Description of drawings

Fig. 1 is the structural representation of the utility model;

Fig. 2 is a structural schematic diagram of the ignition system of the present invention.

Detailed ways

Below in conjunction with accompanying drawing, the utility model is further described:

As shown in Figure 1, the experimental device for measuring the combustion characteristics of cables in an oxygen-enriched environment described in this embodiment includes a housing 1 on which an air intake system, an exhaust system, a cable support system, and an ignition system are arranged. , Combustion parameter testing system, oxygen monitoring system and data acquisition system.

The housing 1 is made of stainless steel with a diameter of 50 cm, a wall thickness of 2 mm, and a height of 120 cm. The bottom of the housing 1 is sealed, and the top has a mouth with a diameter of 100 mm;

The air intake system includes an oxygen intake system and a nitrogen intake system. Each system is composed of a gas cylinder 2, an air intake pipe 3, and a flow controller 4. Two 10mm thick air intake pipes 3 are threaded on a stainless steel on shell 1;

The exhaust pipe 6 of the exhaust system has a diameter of 100mm, and is welded with the shell 1 at the top opening, and a high-temperature-resistant smoke exhaust fan 5 is installed in the exhaust pipe 6;

The cable support system is welded on the inner wall of the stainless steel shell 1 by the bracket 7, located above the intake pipe, and the crucible 8 is placed on the other end of the bracket 7;

As shown in Figure 2, the ignition system consists of a switch 10, wires 11, high-temperature ceramic tube 12, and heating wire 13. The heating wire is made of nickel-chromium heating wire, and the heating temperature can reach about 900°C. The heating wire 12 is arranged inside the crucible 8 , close to the inner surface of the crucible 8, the test cable 9 is cut into sections and placed on the heating wire, the wire 11 extends into the inside of the housing 1 from the opening on the side wall of the housing 1, and the wire 11 passes through the high-temperature ceramic tube 12 inside the housing 1 , the high-temperature ceramic tube 12 protects the electric wire 11 from being burned by the high-temperature flame;

Combustion parameter test system is made up of thermocouple bundle 14, gas sensor 15, radiant heat flowmeter 16, and thermocouple bundle 14 is arranged above crucible 8, and the vertical distance with crucible 8 can measure cable 9 flame centerline temperature by thermocouple bundle 14 As the standard, the gas sensor 15 is arranged in the flue gas plume area above the flame of the cable 9. The gas sensor 15 can measure gases in the combustion flue gas such as carbon dioxide, carbon monoxide, and hydrogen chloride. The radiant heat flow meter 16 is fixed on the inner wall of the housing 1, and The flame of the cable 9 is in a horizontal position, and the radiation receiving surface of the radiant heat flow meter 16 faces the flame;

The oxygen monitoring system consists of a steering gear 17, a steering arm 18, an oxygen sensor 19, and a steering gear control board 23. The steering gear 18 is connected to the steering gear 17 and the oxygen sensor 19. Outside the housing 1, the steering gear control board 23 and the steering gear 17 are connected by a control line, and the steering gear can control the horizontal rotation of the steering arm 18, so that the oxygen sensor 19 is between the position close to the crucible 8 and the inner wall area of the housing 1 move;

The data acquisition system is arranged outside the housing 1, and includes a computer 20, a multi-function data acquisition card 21, and a digital-to-analog conversion module 22. The heat flow meter 16 and other modules that need to be measured are connected to the computer 20 at the output end, and the computer 20 is connected to devices such as the flow controller 4, the steering gear control board 23, the ignition switch 10, and the blower fan 5 through the digital-to-analog conversion module 22.

The specific experimental method of the utility model embodiment comprises the following steps:

1. Assemble and install all system accessories firmly.

2, debug the connection between computer 20 and multifunctional data acquisition card 21, analog-to-digital conversion module 22, multifunctional data acquisition card 21 can collect the data of thermocouple beam 14, gas sensor 15 and radiant heat flow meter 16, computer 20 The ignition system switch 10, the gas flow controller 4, the smoke exhaust fan 5 and the steering gear control board 23 can be controlled through the digital-to-analog conversion module 22 to ensure that the data collection and control functions of each system are normal, and the whole system is energized and preheated for more than 30 minutes .

3. Cut the test cable 9 into 30 mm long sections and place them on the heating wire 13 in the crucible 8 .

4. Turn on the oxygen and nitrogen cylinders 2 respectively, turn on the oxygen and nitrogen flow controllers 4, adjust the ratio of oxygen and nitrogen intake, so that the inner chamber of the housing 1 forms an oxygen-enriched environment, and use the steering gear 17 to control the oxygen sensor 19 to be in the crucible 8 Nearby, test the oxygen content near the crucible, and then move the oxygen sensor 19 close to the inner wall of the housing 1 to prevent the flame temperature in the crucible 8 from burning out the oxygen sensor 19.

5. Turn on the ignition switch 10, the heating wire 13 heats the test cable 9, the temperature of the heating wire 13 can reach 900°C, after igniting the test cable 9, turn off the ignition switch 10, and turn on the exhaust fan 5.

6. Record the data of thermocouple beam 14, gas sensor 15, and radiant heat flow meter 16, and obtain the flame temperature and flame radiation of the test cable burning in an oxygen-enriched environment, as well as carbon dioxide, carbon monoxide, hydrogen chloride and other gases in the generated flue gas concentration.

7. After the cable 9 is burnt out, turn off the gas cylinder 2, save the experimental data, turn off the data acquisition related modules, turn off the fan 5, and clean the crucible after the temperature of the crucible 8 drops to normal temperature.

8. Organize the data to obtain the flame temperature, flame radiation, smoke composition and other combustion characteristics of cables under different oxygen-enriched environments, and provide a basis for analyzing the fire hazard analysis of cables under oxygen-enriched environments.

This embodiment has a simple structure and strong operability, and provides a simple and feasible experimental device for studying the combustion characteristics of cables in an oxygen-enriched environment, and the test results are accurate and repeatable.

The above-mentioned embodiments are only described to the preferred implementation of the utility model, and are not limited to the scope of the utility model. Various deformations and improvements made should fall within the protection scope of the present utility model.

Claims (7)

1. An experimental device for measuring the combustion characteristics of cables in an oxygen-enriched environment, comprising a housing (1), characterized in that: it also includes an air intake system, an exhaust system, a cable support system, an ignition system, a combustion parameter testing system, an oxygen Monitoring system and data acquisition system; The air intake system includes a gas cylinder (2), an air intake pipe (3) and a flow controller (4), the flow controller (4) is arranged on the air intake pipe (3), and one end of the air intake pipe (3) Connect the cylinder (2), and connect the other end to the housing (1); The exhaust system includes an exhaust pipe (6) and a smoke exhaust fan (5). The exhaust pipe (6) is arranged on the top of the casing (1) and communicates with the casing (1). The inside of the exhaust pipe (6) A high temperature resistant smoke exhaust fan (5) is installed; The cable support system includes a bracket (7), one end of the bracket (7) is arranged laterally on the inner wall of the casing (1), and is located above the air intake duct (3), and the other end of the bracket (7) is set with a crucible (8 ); The ignition system includes a switch (10), wires (11), high-temperature ceramic tube (12) and heating wire (13), the switch (10), wires (11) and heating wire (13) are connected in sequence, and the heating wire (13 ) is arranged inside the crucible (8), the test cable (9) is cut into sections and placed on the heating wire (13), and the wire (11) extends into the inside of the housing (1) from the opening on the side wall of the housing (1); The combustion parameter testing system includes a thermocouple bundle (14), a gas sensor (15), and a radiant heat flow meter (16). The thermocouple bundle (14) is arranged above the crucible (8), and the thermocouple bundle (14) can measure The flame center line temperature of the test cable (9) is set on the heating wire (13), the gas sensor (15) is set in the smoke plume area above the flame of the test cable (9), and the radiation heat flow meter (16) is fixed on the shell ( 1) on the inner wall; The oxygen monitoring system includes a steering gear (17), a steering arm (18), an oxygen sensor (19) and a steering gear control panel (23), the steering arm (18) is connected to the steering gear (17) and the oxygen sensor (19), The steering gear (17) is fixed on the housing (1), the steering gear (17) control board (23) is arranged outside the housing (1), and the steering gear control board (23) and the steering gear (17) are connected by a control wire , the steering gear (17) can control the horizontal rotation of the steering arm (18), so that the oxygen sensor (19) is close to the crucible (8); The data acquisition system is arranged outside the casing (1), and includes a computer (20), a multi-function data acquisition card (21), a digital-to-analog conversion module (22), and the analog input terminals of the multi-function data acquisition card (21) are respectively Connect the thermocouple bundle (14), the gas sensor (15) and the radiant heat flow meter (16), the output end of the multi-function data acquisition card (21) is connected to the computer (20), and the computer (20) is respectively connected to the flow controller (4) , steering gear control panel (23), ignition switch (10) and fan (5). 2. The experimental device for measuring the combustion characteristics of cables in an oxygen-enriched environment according to claim 1, wherein the air intake system includes an oxygen air intake system and a nitrogen air intake system, and each system includes a gas cylinder ( 2), intake pipe (3), flow controller (4). 3. The experimental device for measuring the combustion characteristics of cables in an oxygen-enriched environment according to claim 2, characterized in that: the heating wire (13) is a nickel-chromium heating wire, and the heating temperature can reach 900°C. 4. The experimental device for measuring the combustion characteristics of cables in an oxygen-enriched environment according to claim 3, characterized in that: the electric wire (11) passes through the high-temperature ceramic tube (12) inside the casing (1). 5. The experimental device for measuring cable combustion characteristics in an oxygen-enriched environment according to claim 4, characterized in that: the gas sensor (15) can measure carbon dioxide, carbon monoxide, and hydrogen chloride gas. 6. The experimental device for measuring the combustion characteristics of cables in an oxygen-enriched environment according to claim 5, characterized in that: the radiant heat flow meter (16) and the flame of the test cable (9) are in a horizontal position. 7. The experimental device for measuring the combustion characteristics of cables in an oxygen-enriched environment according to claim 6, characterized in that: the computer (20) is connected to the flow controller (4) and steering gear control through a digital-to-analog conversion module (22) plate (23), ignition switch (10) and fan (5).