CN111443269A - A ternary gas distribution spark test device, test system and test method thereof - Google Patents

Abstract

The invention discloses a ternary gas distribution spark test device, a test system and a test method thereof. The experimental system comprises an oxygen analyzer, a flow controller, a ternary gas distribution spark test device, a gas circuit control valve, a filter, a control unit; the gas circuit control valve and the flow controller are sequentially arranged on the intake pipe between the gas cylinder and the ternary gas distribution spark test device, the oxygen analyzer is arranged on the outlet pipe of the ternary gas distribution spark test device, and the oxygen analyzer The output end, the filter and the control unit are connected in sequence, and the control unit is also connected with the air circuit control valve. The ternary gas distribution intrinsically safe spark test device of the present invention. The device solves the above-mentioned problem that only binary gas distribution can be realized and the gas distribution method is single by realizing the ternary simultaneous gas distribution mode for hydrogen, air and oxygen, and adopting the automatic-manual control method; at the same time, the device Modifications to components such as tungsten wires and cadmium discs allow it to test circuits that output 3‑10A.

Description

A ternary gas distribution spark test device, test system and test method thereof

technical field

The invention relates to the technical field of explosion-proof spark test, in particular to a ternary gas distribution spark test device, a test system and a test method thereof.

Background technique

In the spark test, due to the different safety spark test devices in different countries, the data contradict each other. In the early 1970s, the German spark test device was recommended by the International Electrotechnical Commission (IEC) as the standard spark test device. At present, the member countries around the world still use the IEC standard safety spark test device.

Domestic explosion-proof inspection institutions have also carried out research and development on intrinsically safe spark devices, mainly those developed by Chongqing Coal Research Institute and Shanghai explosion-proof inspection station. In GB3836.4-2010 "Explosive Atmospheres Part 4: Equipment Protected by Intrinsically Safe "i", a certain safety factor is required to be added to the spark test of intrinsically safe equipment, and the method of increasing the safety factor is in the above standard Two methods are mentioned: while testing, by increasing the voltage or current to increase the safety factor or if this is not suitable, the safety factor can be met by using a more severe explosive test mixture.

Based on the status quo of the intrinsically safe spark test devices at home and abroad described above, no matter what kind of intrinsically safe spark test device is used, there are certain limitations:

(1) Only binary gas distribution can be achieved; the intrinsically safe spark test device can only be used for binary gas distribution, which leads to the need to modify the circuit during the inspection and testing of intrinsically safe equipment to meet the requirements of the standard for safety factor, which is time-consuming It is laborious and increases the inspection cycle.

(2) The gas distribution method is single and cannot meet various needs; according to the research situation, the gas distribution system of the intrinsically safe spark test devices currently used by various inspection agencies is flow gas distribution or pressure gas distribution, and the flow gas distribution is suitable for automatic Air distribution has the disadvantage of accurate air distribution but slow speed; pressure mode air distribution is suitable for manual air distribution, which has the disadvantage of fast speed but low precision.

(3) The current range of the test circuit is limited to 0 ~ 3A: during the detection process of the high-current intrinsically safe equipment, the difference between the tungsten wire and the grid plate produces a high temperature, which affects the accuracy of the test. Therefore, the intrinsically safe spark test produced in Hungary is included. The device and the testing device independently developed by the domestic testing organization can only test the intrinsically safe equipment with a current in the range of 0 to 3A, and can do nothing for circuits with a current of 3 to 10A. In particular, the Power-i power supply system currently researched by German PTB has an output current greater than 3A. At this time, the above-mentioned detection equipment loses its value.

Based on the above problems, there is an urgent need in the industry to develop a ternary gas distribution intrinsically safe spark test device or system capable of automatic-manual hybrid control.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the above-mentioned deficiencies in the prior art, and to provide a ternary gas distribution spark test device, a test system and the same capable of automatic-manual hybrid control and capable of testing a circuit outputting a current of 3-10A. experiment method.

The object of the present invention is achieved through the following technical solutions:

A ternary gas distribution spark test device, comprising: a flameproof casing, a bottom plate, and an electrode assembly for generating closed sparks and open-circuit sparks in an explosive test mixture; the electrode assembly includes a tungsten wire, a pole grip, a first conductive screw, a second Two conductive screws, a cadmium disc, a transmission gear, a motor, a first current input piece and a second current input piece; the flameproof casing is fixed on the bottom plate, the flameproof casing and the bottom plate form a cavity that can accommodate the explosive test mixture, and the bottom plate is provided with There is an air inlet and an air outlet, the tungsten wire, the pole grip, the cadmium disc, the upper end of the first conductive screw and the upper end of the second conductive screw are all arranged in the cavity, and the upper end of the first conductive screw is fixed with a pole grip, a pole grip A tungsten wire vertically downward is arranged at the bottom of the second conductive screw, and a cadmium disk is fixed on the upper end of the second conductive screw; the pole grip, the tungsten wire and the cadmium disk constitute a group of electrodes; the middle of the second conductive screw and the middle of the first conductive screw are fixed on the On the transmission gear, the lower end of the first conductive screw is connected with the motor, one end of the first current input piece is connected with the first conductive screw, and one end of the second current input piece is connected with the second conductive screw.

Preferably, it also includes: a pressure-bearing plate, a clamp and an insulating plate; the insulating plate is fixed on the lower end of the clamp, the flameproof casing is successively fixed under the clamp by the pressure-bearing plate and the clamping bolt, and both ends of the bottom plate pass through the clamp Clamps, and clamps are detachably attached.

Preferably, it also includes: a first insulating support member, a second insulating support member, a first insulating bolt for fixing the first current input member, a second insulating bolt for fixing the second current input member; the first insulating bolt and the second insulating bolts are all fixed on the insulating plate; the first conductive screw rod is fixed by the first insulating support after passing through the bottom plate; the second conductive screw rod is fixed by the second insulating supporting member after passing through the bottom plate.

Preferably, the number of tungsten wires is 4, the 4 tungsten wires are fixed on the pole grip with a circumferential diameter of 50mm, the distance between the pole grip and the cadmium disc is 10mm, and the second conductive screw, The first conductive screws are 31mm apart.

Preferably, the explosion-proof casing is a metal explosion-proof casing, and the metal explosion-proof casing is an explosion container with a volume of 250 cm ³ and capable of withstanding an explosion shock pressure of more than 1.5 MPa.

Preferably, the top of the metal explosion-proof casing is provided with a glass transparent member for observing the internal structure of the device.

A test system based on the above-mentioned ternary gas distribution spark test device, comprising: an oxygen analyzer, a flow controller, a ternary gas distribution spark test device, a gas circuit control valve, a filter, and a control unit; The controller is arranged on the intake pipe between the gas cylinder and the ternary gas distribution spark test device in turn, the oxygen analyzer is arranged on the outlet pipe of the ternary gas distribution spark test device, the output end of the oxygen analyzer, the filter, the control The units are connected in sequence, and the control unit is also connected to the gas circuit control valve, wherein the number of gas cylinders, gas circuit control valves, and flow controllers are all N, and each gas cylinder, gas circuit control valve, and flow controller form a gas distribution channel. After the N-way gas is mixed, it is input into the intake pipe of the ternary gas distribution spark test device.

A test method based on the above-mentioned test system, comprising:

S1, configure the gas with the preset standard concentration;

S2, input the gas into the ternary gas distribution spark test device, energize the spark test device, and conduct a spark test; if the gas is detonated, the test is passed, and step S3 is executed, if the gas is not detonated, the gas solubility is calibrated , and execute step S2;

S3, after the spark test, use compressed air to replace the gas inside the ternary gas distribution spark test device, and discharge the exhaust gas generated by the internal explosion to the outside.

Preferably, step S2 includes: connecting two ends of the external circuit to the other end of the first current input member and the other end of the second current input member respectively; setting the number of revolutions of the motor according to the external circuit; A conductive screw and a second conductive screw are driven to rotate, and through the relative movement between the tungsten wire and the cadmium disc, the circuit in the spark test device is constantly on and off, generating arc sparks, and detecting whether the energy of the arc spark can ignite the shell flammable gas inside the body.

Preferably, step S2 further includes: when the tungsten wire and the cadmium disk are in contact, the spark test device is short-circuited; when the electrode and the cadmium disk are separated, the spark test device is open-circuited; setting the number of revolutions of the motor according to the external circuit includes: if the external circuit If it is a DC circuit, the number of revolutions of the motor is 400 revolutions/5min, and each polarity is 200 revolutions; if the external circuit is an AC circuit, the number of revolutions of the motor is 1000 revolutions/12.5min; if the external circuit is a capacitor circuit, the number of revolutions of the motor 400 rpm/5min, 200 rpm for each polarity.

Compared with the prior art, the present invention has the following advantages:

The ternary gas distribution intrinsically safe spark test device of the present invention. The device solves the above-mentioned problem that only binary gas distribution can be realized and the gas distribution method is single by realizing the ternary simultaneous gas distribution mode for hydrogen, air and oxygen, and adopting the automatic-manual control method. By improving the components such as tungsten wire and cadmium disc, it can test the circuit outputting 3-10A current.

Description of drawings

The accompanying drawings forming a part of the present application are used to provide further understanding of the present invention, and the exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the attached image:

FIG. 1 is a schematic structural diagram of the ternary gas distribution spark test device of the present invention.

Fig. 2 is the principle block diagram of the test system of the present invention.

Among them, 1-insulating plate, 201-first current input piece, 202-second current input piece, 301-first insulating bolt, 302-second insulating bolt, 401-first insulating support, 402-second insulating Support, 5-air inlet, 6-base plate, 7-tungsten wire, 8-pole grip, 9-clamp bolt, 10-pressure plate, 11-clamp, 12-flameproof shell, 13-cadmium plate , 14-insulation pad, 15-air outlet, 16-transmission gear, 17-insulation connector, 18-motor, 19-first conductive screw, 20-second conductive screw.

Detailed ways

The present invention will be further described below with reference to the accompanying drawings and embodiments.

Referring to Figure 1, a ternary gas distribution spark test device includes: a flameproof casing 12, a bottom plate 6 and an electrode assembly for generating closed sparks and open sparks in an explosive test mixture; the electrode assembly includes a tungsten wire 7, a pole grip 8. The first conductive screw 19, the second conductive screw 20, the cadmium disc 13, the transmission gear 16, the motor 18, the first current input member 201 and the second current input member 202; The explosion casing 12 and the bottom plate 6 form a cavity that can accommodate the explosive test mixture. The bottom plate 6 is provided with an air inlet 5 and an air outlet 15, a tungsten wire 7, a pole grip 8, a cadmium disc 13, the upper end of the first conductive screw 19, The upper ends of the second conductive screws 20 are all arranged in the cavity, the pole grip 8 is fixed on the upper end of the first conductive screw 19, the bottom of the pole grip 8 is provided with a vertically downward tungsten wire 7, and the upper end of the second conductive screw 20 is fixed There is a cadmium disc 13; the pole grip 8, the tungsten wire 7 and the cadmium disc 13 constitute a group of electrodes; the middle part of the second conductive screw 20 and the middle part of the first conductive screw 19 are fixed on the transmission gear 16, and the lower end of the first conductive screw 19 Connected to the motor 18 , one end of the first current input member 201 is connected to the first conductive screw 19 ; one end of the second current input member 202 is connected to the second conductive screw 20 .

Among them, binary gas distribution refers to the mixture of combustible gas and air; ternary gas distribution refers to the addition of a new gas distribution, that is, the mixture of combustible gas, air and oxygen.

In this embodiment, the ternary gas distribution spark test device further includes: a pressure-bearing plate 10, a clamp 11 and an insulating plate 1; the insulating plate 1 is fixed on the lower end of the clamp 11, and the flameproof casing 12 passes through the pressure-bearing plate 10, Under the clamping bolt 9 to fix the clamp 11 , both ends of the bottom plate 6 pass through the clamp 11 and are detachably connected to the clamp 11 .

In this embodiment, the ternary gas distribution spark test device further includes: a first insulating support member 401, a second insulating support member 402, a first insulating bolt 301 for fixing the first current input member 201, and a second insulating support member 401 for fixing the second The second insulating bolt 302 of the current input member 202; the first insulating bolt 301 and the second insulating bolt 302 are fixed on the insulating plate 1; The two conductive screws 20 are fixed by the second insulating support member 402 after passing through the bottom plate 6 . The ternary gas distribution spark test device also includes: insulating pads 14 and 17 - insulating connectors. The flameproof casing 12 is fixed on the bottom plate 6 through the insulating gasket 14 . The motor 8 drives the transmission gear 16 to rotate under working conditions through the insulating connector 17 .

In this embodiment, the number of tungsten wires 7 is 4, and the 4 tungsten wires 7 are fixed on the pole handle 8 with a circumferential diameter of 50mm. The second conductive screw 20 and the first conductive screw 19 of the pole grip 8 are separated by 31 mm. The explosion-proof casing 12 is a metal explosion-proof casing, and the metal explosion-proof casing is an explosion container with a volume of 250cm3 and capable of withstanding an explosion shock pressure above 1.5MPa. The top of the metal flameproof casing is provided with a transparent glass part for observing the internal structure of the device.

Referring to Figure 2, a test system based on the above-mentioned ternary gas distribution spark test device, including: an oxygen analyzer, a flow controller, a ternary gas distribution spark test device, a gas circuit control valve, a filter, and a control unit; a gas circuit The control valve and the flow controller are sequentially arranged on the intake pipe between the gas cylinder and the ternary gas distribution spark test device, the oxygen analyzer is arranged on the outlet pipe of the ternary gas distribution spark test device, and the output end of the oxygen analyzer, The filter and the control unit are connected in sequence, and the control unit is also connected with the gas circuit control valve, wherein the number of gas cylinders, gas circuit control valves, and flow controllers are all N, and each gas cylinder, gas circuit control valve, and flow controller form a One way gas distribution, N way gas is mixed and input into the intake pipe of the ternary air distribution spark test device. In this embodiment N=3, ternary gas distribution is realized.

The experimental principle of the test system of this scheme is:

The gas passes through the gas circuit control valve and the flow controller, enters the mixing tank of the ternary gas distribution spark test device and flows out, and enters the oxygen analyzer for sampling. The electrical signal generated by the sampling is filtered by the filter and then enters the control unit. After processing and analysis, the feedback signal is provided to the air circuit control valve to control the opening of the air circuit valve.

A flow controller is installed before the inlet end of the ternary gas distribution spark test device, and the flow controller calculates the volume of gas entering the interior of the shell of the ternary gas distribution spark test device, so as to realize the ternary control of hydrogen, air and oxygen. Gas distribution at the same time. For example, it can be calculated that oxygen enters 1L, air 1L, and combustible gas 2L. The flow ratio mixing method is one of the dynamic gas distribution methods. It is to obtain standard gas by strictly controlling the flow rate of a certain proportion of combustible gas and combustion-supporting gas and mixing them. Compared with the preparation of bottled standard gas (gas with mixed gas concentration already configured), this method can prepare various standard gases with different component contents that meet the needs on the same gas distribution device, and is especially suitable for preparation laboratories. Required low level standard gas. A gas circuit control valve is also arranged before the intake end of the ternary gas distribution spark test device. On the one hand, the air circuit control valve can be manually adjusted to control the speed of the intake air; on the other hand, the control unit processes and analyzes the electrical signals obtained by sampling and provides feedback signals to the air circuit control valve to dynamically adjust the gas intake valve. The opening degree can be adjusted automatically to realize the automatic adjustment of the gas circuit control valve, and finally the automatic-manual mixed control is realized, which solves the problem that the current intrinsically safe spark experimental device can only realize binary gas distribution and the gas distribution method is single.

In this scheme, the diameter of the tungsten wire 7 is changed from 0.2mm to the tungsten wire 7 between 0.37mm and 0.43mm, and the free length of the tungsten wire 7 is shortened to 10.5mm. The shortening of the net length of the tungsten wire 7 can reduce the cadmium disk. 13 wear. When the tungsten wire 7 is rotated to contact the cadmium disc 13, a short circuit occurs in the spark test device; at this time, the external circuit, the first current input member 201, the first conductive screw 19, the pole grip 8, the tungsten wire 7, the cadmium disc 13, The second conductive screw 20, the second current input member 202 and the external circuit form a closed loop. At this time, the total resistance of the device including the commutation contact resistance (the resistance when the tungsten wire 7 and the cadmium disc 13 are in contact) is reduced to less than 10mΩ, which is used in combination with the brush type of the automobile industry and the brass bushing on the device shaft The same method can be used to increase the contact area and reduce the contact resistance. The increase in the diameter of the tungsten wire 7 can reduce the resistance, flow a larger current, and reduce its own heating, increase the thermal effect, reduce the minimum ignition current, improve the ignition ability of the device, and avoid the test results caused by the hot temperature ignition invalid. The total inductance of the test device and the inductance of the wiring to the circuit under test must be minimized and not exceed 1 μH.

A test method for the above-mentioned test system, comprising:

S1, configure gas with preset standard concentration; configure gas with standard concentration, see Table 1 and Table 2 for specific data;

S2, input the gas into the ternary gas distribution spark test device, energize the spark test device, and conduct a spark test; if the gas is detonated, the test is passed, and step S3 is executed, if the gas is not detonated, the gas solubility is calibrated , and perform step S2; specifically, step S2 includes: connecting the two ends of the external circuit to the other end of the first current input member 201 and the other end of the second current input member 202 respectively; setting the rotation of the motor 18 according to the external circuit The electrode and the cadmium disk 13 are rotated under the driving of the first conductive screw 19 and the second conductive screw 20, respectively, through the relative movement between the tungsten wire 7 and the cadmium disk 13, the circuit in the spark test device is kept on and off, An arc spark is generated to detect whether the energy of the arc spark can ignite the combustible gas inside the casing.

Among them, the calibration of the gas solubility includes: using the specified calibration current, see Table 1 and Table 2, to calibrate the gas solubility.

In this embodiment, since the tungsten wire 7 is fixed on the pole holder 8, the first conductive screw 19 is rotated and rubbed against the cadmium disc 13. Therefore, step S2 also includes: when the tungsten wire 7 and the cadmium disk 13 are in contact, a short circuit occurs in the spark test device; when the tungsten wire 7 and the cadmium disk 13 are separated, an open circuit occurs in the spark test device; and the number of revolutions of the motor 18 is set according to the external circuit. Including: if the external circuit is a DC circuit, the number of revolutions of the motor 18 is 400 revolutions/5min, and each polarity is 200 revolutions; if the external circuit is an AC circuit, the number of revolutions of the motor 18 is 1000 revolutions/12.5min; if the external circuit is Capacitive circuit, the number of revolutions of the motor 18 is 400 revolutions/5min, and each polarity is 200 revolutions.

S3, after the spark test, use compressed air to replace the gas inside the ternary gas distribution spark test device, and discharge the exhaust gas generated by the internal explosion to the outside.

The technical indicators of this program include the following:

1. At both ends of the electrode structure, when the electrode is open, the self-capacitance of the test device (ternary gas spark test device) should not exceed 30pF (under 1V 1000Hz and 1.5MHz test conditions), and when the electrode is closed, the resistance should be under 1A DC current. It does not exceed 0.15Ω, and its own inductance does not exceed 3μH (under 1V 1000Hz and 1.5MHz test conditions).

2. Sensitivity of spark device (ternary gas distribution spark test device): The spark test device should be operated in a 24V DC circuit with an air-core coil of 95(±5)mH. The circuit should be set according to the current given value in the calibration circuit of the corresponding category in Table 7 and Table 8 of GB 3836.4-2010. When the pole grip 8 of the spark test device is connected to the positive pole and rotates within 440 revolutions, if an explosive mixture ignites, the sensitivity of the device is considered to be qualified.

3. Gas concentration: The spark test device conducts gas distribution according to the gas concentration given values of the corresponding categories in GB 3836.4-2010 Table 1 and Table 8, and measures whether the actual gas concentration is consistent with the set value.

4. Spark test device pole grip 8 disc speed (tolerance: 0-10%):

(a) For DC circuits, 400 turns (5min), 200 turns for each polarity;

(b) For AC circuits, 1000 rpm (12.5min);

(c) For capacitive circuits, 400 turns (5min), 200 turns per polarity. The charging time of the capacitor (the charging time of the capacitor is about 20ms);

(d) The actual rotational speed of the motor 18 can be adjusted by a program.

5. Mechanical dimensions: Four tungsten wires 7 are fixed on the pole handle 8 with a circumference of 50mm, the distance between the pole handle 8 and the cadmium plate 13 is 10mm, and the two axes driving the cadmium plate 13 and the pole handle 8 are separated by 31mm.

6. Tungsten wire 7: The diameter is 0.37-0.43mm.

7. For circuits with a test current of 3-10A. The total resistance of the device (ternary gas distribution spark test device) including the reversing contact resistance (the resistance when the tungsten wire 7 and the cadmium disc 13 are in contact) should be reduced to less than 10mΩ, the total inductance of the test device and the connection line with the circuit under test. Inductance must be minimized and not exceed 1μH.

The ternary gas distribution spark test device has the following functions:

(1) The device can test the intrinsic safety performance of intrinsically safe circuits of various mine and factory explosion-proof electrical equipment.

(2) The device should be able to test and calibrate after the test parameters are set.

(3) The device can realize ternary gas distribution, that is, three gases can be automatically and proportionally configured in real time at one time, and the connected gas sources must include hydrogen (H2), methane (CH4), propane (C3H8), ethylene ( C2H4), oxygen (O2) and air (AIR).

(4) The device should be able to real-time closed-loop gas distribution during each test process to ensure the concentration of mixed gas, the gas distribution time should be as short as possible, and the hydrogen, oxygen, methane, propane, and ethylene concentrations should be displayed accurately in real time during the gas distribution process. Displays the concentration of hydrogen (or methane, propane, ethylene) and oxygen in the ternary gas distribution, and only displays the hydrogen (or methane, propane, ethylene) concentration in the binary gas distribution.

(5) The device can monitor the whole test process in real time, and can display the action flow chart and various key data of the whole test on the computer screen.

(6) The device realizes control functions such as exhausting, vacuuming, gas distribution, concentration control, concentration measurement, spark test, ignition judgment, main electrode revolution count, etc. It should automatically stop and display the revolution value when it is ignited.

(7) The device can measure and display the voltage and current parameters of the calibration circuit and the circuit under test. The external circuit is provided with a DC switching power supply, which has a voltmeter and an ammeter, which can display the output voltage and current.

(8) The device should be able to complete the entire test process without turning on the computer if the tester does not need to monitor the entire test process in real time.

(9) The device can automatically calculate the number of revolutions of each polarity according to the total number of revolutions specified by the characteristics of different equipment under test, and automatically realize the change of polarity and the calculation of the number of test revolutions required for each polarity during the test. . The motor 18 has a rotation speed counter. After a fixed number of revolutions can be set, the motor 18 stops rotating. The motor 18 has a rotary encoder that can count the number of revolutions of the motor 18 .

(10) The device can print the test results, and the data is true and reliable, which is convenient for later reference.

(11) Unless otherwise specified, the mechanical dimension tolerance of the machined parts of the device should be ±2.0%, the length and diameter tolerance of tungsten wire 7 should be ±10%, and the voltage and current tolerance should be ±1.0%.

(12) The appearance of the console of the device is beautiful and generous, the layout and arrangement of the internal components are reasonable, and the gas path and line direction are clear and tidy, which is convenient for maintenance. The buttons and switches on the table are simple and reasonable in design and easy to operate.

(13) The device console is composed of explosion container, calibration circuit, PLC, industrial computer, vacuum pump, gas concentration controller, explosion-proof solenoid valve, various sensors and various digital instruments.

(14) The tested voltage, tested current, calibration current, test speed, test speed, explosion vessel pressure, hydrogen concentration, oxygen concentration, methane concentration, propane concentration, and ethylene concentration are digitally displayed on the device console, and the display accuracy is required High, real-time refresh is fast.

(15) Set binary and ternary test selection, safety factor selection, subject and calibration selection device, calibration category selection switch, ignition, subject and calibration indicator lights, power supply, air intake and rotary buttons on the device console , set the potentiometer to adjust the speed of the motor 18.

(16) A large-screen display of 22# or more must be embedded in the device console to display the dynamic flow chart of the test process and various key data.

The environmental adaptability requirements of this ternary gas distribution spark test device:

Ambient temperature: 20±15℃

Ambient humidity≤95%RH

Atmospheric pressure: 86～110kPa

The performance of this ternary gas distribution spark test device:

(1) Explosive container

The explosion container generally meets the requirements of Appendix B of the GB3836.4-2010 standard.

A set of electrodes is arranged in the explosion container, one is a rotating cadmium disk 13 with two grooves, and the other is a pole grip 8 composed of four tungsten wires 7 .

The explosion container is made of stainless steel and transparent plexiglass, both of which can withstand the explosion pressure of 1500kPa.

The volume of the explosion container is 250cm ³ , and the thickness of the container is 6mm±0.5mm (stainless steel) and 9.5mm±0.5mm (transparent organic glass).

The free length of the tungsten wire 7 of the explosion container is 11mm, and the diameter is divided into two types: 0.2mm and 0.4mm.

The explosive container tungsten wire 7 is fixed on a pole handle 8 made of brass with a diameter of 50mm.

The distance between the pole handle 8 of the explosion container and the cadmium plate 13 should be 10mm, the two axes driving the cadmium plate 13 and the pole handle 8 should be separated by 31mm, and the two axes and the chassis of the test device must be insulated from each other.

Electric current from the explosion vessel flows in and out through sliding electrodes on the shafting.

The two shafts of the explosion container are meshed by non-conductive gears with a gear ratio of 50:12.

The self-capacitance of the two ends of the electrode structure of the explosion container does not exceed 30pF when the electrodes are open-circuited.

When both ends of the electrode structure of the explosion container are closed, the resistance does not exceed 0.15Ω under 1-3A direct current, and the resistance does not exceed 0.01Ω under 3-10A direct current.

When both ends of the electrode structure of the explosion container are closed, the self-inductance does not exceed 3μH under 1-3A DC current, and the self-inductance does not exceed 1μH under 3-10A DC current.

(2) Device sensitivity calibration

The device should use 24V voltage to calibrate its sensitivity, and the calibration loop inductance is 95(±5)mH. The device can adjust its calibration loop current to the following values according to different safety factors and equipment categories (I, IIA, IIB, IIC).

When the safety factor of Class I equipment is 1.0 times, the calibration current is 110 ~ 111mA.

The calibration current is 100 ~ 101mA when the safety factor is 1.0 times for Class IIA equipment

The calibration current is 65～66mA when the safety factor is 1.0 times for Class IIB equipment

The calibration current is 30 ~ 30.5mA when the safety factor is 1.0 times for Class IIC equipment

When the safety factor of Class I equipment is 1.5 times, the calibration current is 73 ~ 74mA.

The calibration current is 66～67mA when the safety factor is 1.5 times for Class IIA equipment

The calibration current is 43~44mA when the safety factor is 1.5 times for Class IIB equipment

The calibration current is 20 ~ 21mA when the safety factor is 1.5 times for Class IIC equipment

(3) Number of revolutions control:

The rotational speed of the device pole grip 8 is usually set at 80 rpm, but can be adjusted for different types of test circuits.

For the DC circuit, the number of test revolutions is 400 revolutions (5min), 200 revolutions for each polarity, and the tolerance is 0% to +10%.

For the AC circuit, the number of test revolutions is 1000 revolutions (12.5min), and the tolerance is 0% to +10%.

The number of test revolutions for the capacitive circuit is 400 revolutions (5min), 200 revolutions for each polarity, and the tolerance is 0% to +10%. And it must be ensured that the capacitor has enough charging time, which is not less than 3 times the time constant. The normal charging time is about 20ms. When the charging time is insufficient, the device can slow down the rotation speed of the spark test device to drag the motor 18 and increase the test time. , keeping the number of test revolutions unchanged to maintain the same number of sparks.

(4) Safety factor:

The device can use a safety factor of 1.0 times or 1.5 times to test the test circuit. The purpose of the test with a safety factor of 1.5 times is to ensure that the type test and evaluation are carried out under the circuit conditions that are easier to ignite together than the original circuit.

For inductive and resistance circuits, the device can obtain 1.5 times the safety factor by reducing the current limiting resistance value, and should also be able to obtain 1.5 times the safety factor by increasing the power supply voltage to increase the current to 1.5 times the fault current.

For capacitive circuits, the device shall be able to obtain a safety factor of 1.5 times by increasing the voltage to 1.5 times the fault voltage. The device was able to obtain a safety factor of 1.5 times by testing the original circuit with a more flammable gas mixture. When the device is tested according to 1.5 times the explosive gas mixture, it is equivalent to 1.5 times the safety factor.

(5) Explosive gas mixture

Table 1 Explosive gas mixture with a safety factor of 1.5 times

Table 2 Explosive gas mixtures with a safety factor of 1.0 times

(6) Device test stability:

The device is tested continuously for 5 times according to the requirements of the sensitivity test conditions, and the gas concentration and current are all ignited as the qualified test.

(7) Tungsten wire 7 fuse device:

It is required to fuse the tungsten wire 7 conveniently and quickly, so as to prevent the end from cracking and small balls.

5.2 Main technical indicators:

(1) The volume of the explosion container is 250cm3

(2) Pressure of explosion container: 1.5MPa

(3) Diameter of tungsten wire 7: Φ0.2mm±0.02mm (under 1～3A DC current),

Φ0.40±0.03mm (under 3～10A DC current)

(4) The internal resistance of the device is less than or equal to 0.15Ω (under 1~3A DC current)

≤10mΩ(under 3～10A DC current)

(5) The self-inductance of the device is less than or equal to 3μH (under 1~3A DC current)

≤1μH (under 3～10A DC current)

(6) The self-capacitance of the device is less than or equal to 30pF (open circuit state)

(7) Test ignition signal: pressure or light

(8) Test speed: 0～120r/min adjustable

(9) Test count: 0～400r (DC test), 0～1000r (AC test)

(10) Test voltage: 0～300V

(11) Test current: 0～10A

(12) Test inductance circuit inductance≤1.0H

(13) Test circuit frequency≤1.5MHz

(14) Criterion for passing the test: the mixed gas is ignited 5 times

(15) Quantity of intake air: binary or ternary gas

(16) Inlet pressure: 0.05～0.15MPa (0.1MPa recommended)

(17) Gas distribution accuracy: ±0.5%

(18) Gas distribution time≤180 seconds (when the container is 250cm ³ )

In summary, this solution provides a manual integrated ternary gas distribution spark test device, which can test circuits with a current of 0 to 10A; the software-controlled gas distribution system is used to achieve short gas distribution cycles and high precision. High requirements; realize the ternary gas distribution mode, eliminate the modification of the test circuit, and improve the inspection efficiency.

The above-mentioned specific embodiments are the preferred embodiments of the present invention, and do not limit the present invention. Any other changes or other equivalent replacement methods that do not deviate from the technical solutions of the present invention are included in the protection scope of the present invention. within.

Claims (10)

1. a ternary gas distribution spark test device, is characterized in that, comprises: flameproof casing, bottom plate and the electrode assembly for producing closed spark and open-circuit spark in explosive test mixture; Electrode assembly comprises tungsten wire, pole grip, a first conductive screw, a second conductive screw, a cadmium disc, a transmission gear, a motor, a first current input member and a second current input member; The flameproof casing is fixed on the bottom plate, the flameproof casing and the bottom plate form a cavity that can accommodate the explosive test mixture, the bottom plate is provided with an air inlet and an air outlet, tungsten wire, pole grip, cadmium plate, the upper end of the first conductive screw, The upper ends of the second conductive screws are all arranged in the cavity, the upper end of the first conductive screw is fixed with a pole grip, the bottom of the pole grip is provided with a vertically downward tungsten wire, and the upper end of the second conductive screw is fixed with a cadmium disk; , tungsten wire and cadmium disc form a group of electrodes; the middle part of the second conductive screw and the middle part of the first conductive screw are fixed on the transmission gear, the lower end of the first conductive screw is connected to the motor, and one end of the first current input piece is connected to the first conductive screw. The conductive screw is connected; one end of the second current input piece is connected with the second conductive screw. 2. The ternary gas distribution spark test device according to claim 1, further comprising: a pressure-bearing plate, a clamp and an insulating plate; The insulating plate is fixed on the lower end of the clamp, the flameproof casing is successively fixed under the clamp through the pressure-bearing plate and the clamping bolt, and both ends of the bottom plate pass through the clamp and are detachably connected with the clamp. 3 . The ternary gas distribution spark test device according to claim 2 , further comprising: a first insulating support member, a second insulating support member, a first insulating bolt for fixing the first current input member, The second insulating bolt used to fix the second current input piece; the first insulating bolt and the second insulating bolt are both fixed on the insulating plate; the first conductive screw is fixed by the first insulating support after passing through the bottom plate; the second conductive screw After passing through the bottom plate, it is fixed by a second insulating support. 4. ternary gas distribution spark test device according to claim 1, is characterized in that, the quantity of tungsten wire is 4, and 4 tungsten wires are fixed on the pole grip with a circumference diameter of 50mm, between the pole grip and the cadmium plate The distance is 10mm, and the second conductive screw and the first conductive screw that drive the cadmium disc and the pole grip respectively are separated by 31mm. 5. The ternary gas distribution spark test device according to claim 1 is characterized in that, the flameproof casing is a metal flameproof casing, and the metal flameproof casing is a volume of 250cm ³ , which can withstand the explosion of the explosion shock pressure of more than 1.5MPa container. 6 . The ternary gas distribution spark test device according to claim 1 , wherein the top of the metal flameproof casing is provided with a glass transparent member for observing the internal structure of the device. 7 . 7. A test system based on the ternary gas distribution spark test device according to any one of claims 1-6, characterized in that, comprising: an oxygen analyzer, a flow controller, a ternary gas distribution spark test device, a gas Circuit control valve, filter, control unit; The gas circuit control valve and the flow controller are sequentially arranged on the intake pipe between the gas cylinder and the ternary gas distribution spark test device, the oxygen analyzer is arranged on the outlet pipe of the ternary gas distribution spark test device, and the output of the oxygen analyzer The terminal, the filter, and the control unit are connected in sequence, and the control unit is also connected to the gas circuit control valve. The number of gas cylinders, gas circuit control valves, and flow controllers are all N. Each gas cylinder, gas circuit control valve, and flow control valve The device forms a one-way gas distribution, and the N-way gas is mixed and fed into the intake pipe of the ternary gas distribution spark test device. 8. a test method based on the described test system of claim 7, is characterized in that, comprises: S1, configure the gas with the preset standard concentration; S2, input the gas into the ternary gas distribution spark test device, energize the spark test device, and conduct a spark test; if the gas is detonated, the test is passed, and step S3 is executed, if the gas is not detonated, the gas solubility is calibrated , and execute step S2; S3, after the spark test, use compressed air to replace the gas inside the ternary gas distribution spark test device, and discharge the exhaust gas generated by the internal explosion to the outside. 9. test method according to claim 8, is characterized in that, step S2 comprises: two ends of the external circuit are respectively connected to the other end of the first current input member and the other end of the second current input member; Set the number of revolutions of the motor according to the external circuit; The electrode and the cadmium disc rotate under the driving of the first conductive screw and the second conductive screw, respectively. Through the relative movement between the tungsten wire and the cadmium disc, the circuit in the spark test device is constantly on and off, generating arc sparks and detecting arc sparks. Whether the energy can ignite the combustible gas inside the shell. 10. The ternary gas distribution spark test device according to claim 1, wherein step S2 further comprises: when the tungsten wire and the cadmium disk are in contact, a short circuit occurs in the spark test device; when the electrode and the cadmium disk are separated, the spark The test device has an open circuit; Setting the number of revolutions of the motor according to the external circuit includes: If the external circuit is a DC circuit, the number of revolutions of the motor is 400 revolutions/5min, and each polarity is 200 revolutions; If the external circuit is an AC circuit, the number of revolutions of the motor is 1000 revolutions/12.5min; If the external circuit is a capacitor circuit, the number of revolutions of the motor is 400 revolutions/5min, and each polarity is 200 revolutions.

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