Cable pyrolysis test equipment

Abstract

The invention relates to cable pyrolysis test equipment in the technical field of cable pyrolysis. The cable pyrolysis test equipment comprises a contact gas detection device, a non-contact gas detection device, a cooler, a gas collection bottle, a gas collection sleeve and a high-pressure bottle, the gas collection bottle comprises a bottle body part and two bottle neck parts, the bottle body part is made of a transparent heat-resistant material capable of expanding along with internal pressure, outer ports of the two bottle neck parts are respectively provided with a gas inlet and a gas outlet, and the non-contact gas detection device performs gas detection corresponding to the bottle body part; the gas collection sleeve comprises a heat transfer sleeve section, two heat insulation sleeve sections and two transition sleeve sections, the outer end walls of the two transition sleeve sections are sleeved with sealing hoops in a clamped mode, the end walls of the two transition sleeve sections are provided with a gas inlet pipe and a gas outlet pipe respectively, the gas inlet pipe is correspondingly communicated with a bottle opening of the high-pressure bottle, and the gas outlet pipe is correspondingly communicated with a gas inlet of the gas collection bottle; gas discharged from an exhaust port of the gas collecting bottle enters a cooler to be cooled and then is guided into a contact type gas detection device; according to the test equipment, characteristic gas can be more completely collected, and the detection diversity and accuracy are improved.

Description

Technical Field

[0001] The invention relates to the technical field of cable pyrolysis, in particular to a cable pyrolysis test device. Background Art

[0002] Cable pyrolysis test, also known as cable combustion test or cable thermal stability test, is a performance test method used to evaluate cables under high temperature or fire conditions. Its main purpose is to simulate the working state of cables in fire or high temperature environments, and evaluate the heat resistance, flame resistance, smoke generation, and toxic gas release of cables. This type of test is crucial to ensure the safety of cables, especially in key locations such as power facilities, chemical plants, hospitals, etc. The entire test process generally includes steps such as cable degradation characteristic gas collection, gas composition analysis, and test temperature and gas concentration relationship model establishment; As shown in a cable insulation layer pyrolysis product sampling device and sampling method disclosed in the Chinese invention patent with announcement number CN115655812A, the existing test methods are mostly to heat the cable for pyrolysis, and then use a straw structure to absorb the scattered characteristic gas, and then inject it into the gas detection device for detection. There are two defects: first, placing the pyrolysis cable in the external environment is not conducive to pyrolysis temperature control, and thus is not conducive to subsequent data analysis and model building. At the same time, it cannot ensure that the piston gas cylinder collects the decomposition characteristic gas completely, which may cause deviations in subsequent concentration measurements; second, the collected characteristic gas needs to be manually transferred, which is inefficient, and the gas detection method is single. Some detection instruments are easily affected by high-temperature gases, reducing detection accuracy. Summary of the invention

[0003] In order to overcome the deficiencies in the background technology and solve the existing technical problems, the present invention discloses a cable pyrolysis test device, which can collect characteristic gases more completely and improve the diversity and accuracy of detection.

[0004] To achieve the above object, the present invention adopts the following technical solution: A cable pyrolysis test device, comprising a contact gas detection device, a non-contact gas detection device, a cooler, a gas collection bottle, a gas collection sleeve arranged outside the cable and a high-pressure bottle for storing high-pressure air, wherein the gas collection bottle, the gas collection sleeve and the high-pressure bottle are respectively provided with a first pressure gauge, a second pressure gauge and a third pressure gauge for measuring internal pressure; the gas collection bottle comprises a bottle body and two bottlenecks symmetrically arranged at both ends of the bottle body, the bottle body is made of a transparent heat-resistant material that can expand with the internal pressure, the outer ports of the two bottlenecks are respectively set as an air inlet and an exhaust port with a switch valve, the non-contact gas detection device corresponds to the air inlet of the bottle body Gas detection is performed; the gas collecting sleeve includes a heat transfer sleeve section, both ends of the heat transfer sleeve section are connected to heat insulation sleeve sections, the outer ends of the two heat insulation sleeve sections are connected to transition sleeve sections, the outer end walls of the two transition sleeve sections are clamped with sealing clamps for clamping the transition sleeve sections close to the cable for sealing, the inner end walls of the two transition sleeve sections are respectively provided with an air inlet pipe and an air outlet pipe, the air inlet pipe is connected to the bottle mouth of the high-pressure bottle through a conduit with a control valve, the air outlet pipe is connected to the air inlet of the air collecting bottle, the gas discharged from the exhaust port of the air collecting bottle enters the cooler through the connected pipeline for cooling, and is then introduced into the contact gas detection device for detection.

[0005] Furthermore, the contact gas detection device is configured as a gas detector, and the non-contact gas detection device is configured as an infrared spectrometer.

[0006] Furthermore, the infrared spectrometer includes a supporting stand, the upper and lower ends of which are respectively equipped with corresponding light emitters and detectors, two cantilever rods are symmetrically fixed on both sides of the middle of the supporting stand, and the outer walls of the two bottlenecks are respectively connected to the outer ends of the two cantilever rods.

[0007] Furthermore, a telescopic cylinder is installed on the side of the gas collecting bottle away from the supporting stand, and an extrusion plate corresponding to the bottle body is fixed to the end of the telescopic rod of the telescopic cylinder.

[0008] Furthermore, an ignition unit corresponding to the cable is installed on the middle wall of the heat transfer sleeve section.

[0009] Furthermore, the central sleeve wall of the heat transfer sleeve section is concave to form a heat conduction portion that contacts the cable.

[0010] Furthermore, the heat-insulating sleeve section is provided with an annular cavity for storing pure water.

[0011] Furthermore, the outer end of the transition sleeve is reduced in diameter and made of rubber material, the sealing clamp is a throat clamp, and two are arranged side by side axially at intervals along each transition sleeve, and a plurality of convex tooth rings are arranged side by side axially on the inner wall of the outer end of the transition sleeve.

[0012] Furthermore, the air inlet pipe and the air outlet pipe are respectively located at the lower end and the higher end of the air collecting sleeve.

[0013] Furthermore, the body of the gas collecting bottle is made of a transparent film-like polysiloxane, polytetrafluoroethylene, polycarbonate or polyimide material.

[0014] Due to the adoption of the above-mentioned technical solution, the present invention has the following beneficial effects: The cable pyrolysis test equipment disclosed in the present invention is divided into two continuous processes: gas collection and gas analysis. The entire collection process is isolated from the external environment to avoid leakage, and air flow is generated through pressure changes, so that the characteristic gas generated in the gas collecting sleeve can be relatively more completely and evenly sent to the gas collecting bottle for collection, and the cable section to be pyrolyzed is placed in the gas collecting sleeve, which is also convenient for temperature control and avoids energy waste; more importantly, the transparent gas collecting bottle can expand adaptively according to the amount of collected gas, thereby further reducing the gas collection pressure compared to traditional piston thrust forced collection, maintaining the uniformity of the collected gas and the stability of the gas pressure, and can be convenient for direct measurement using non-contact measurement methods such as infrared absorption spectroscopy measurement methods, and can also be sent to a contact gas detection device for comprehensive measurement after the gas is cooled; in summary, the entire equipment is simple and easy to control, has strong continuity, and high test efficiency, and can greatly increase the completeness of gas collection and the accuracy of gas detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the implementation structure of the present invention; Figure 2 is a schematic cross-sectional structural diagram of the gas collecting sleeve; Figure 3 It is a side view structural schematic diagram of the infrared spectrometer.

[0016] In the figure: 1. gas collecting bottle; 2. gas collecting sleeve; 201. heat transfer sleeve section; 202. heat insulation sleeve section; 203. transition sleeve section; 204. air inlet pipe; 205. air outlet pipe; 206. annular cavity; 207. heat conduction part; 3. high-pressure bottle; 301. third pressure gauge; 4. sealing clamp; 5. infrared spectrometer; 501. supporting stand; 502. detector; 503. light emitter; 6. cantilever rod; 7. telescopic cylinder; 8. extrusion plate; 9. cooler; 10. gas detector. DETAILED DESCRIPTION

[0017] The technical solution of the present invention will be described below in conjunction with the drawings in the embodiments of the present invention. In the description, it should be understood that if there are terms such as "upper", "lower", "front", "back", "left", "right", etc. indicating directions or positional relationships, they only correspond to the drawings of the present invention and are for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific direction. Embodiment 1:

[0018] Combined with Figure 1 The cable pyrolysis test equipment comprises a contact gas detection device, a non-contact gas detection device, a cooler 9, a gas collecting bottle 1, a gas collecting sleeve 2 arranged outside the cable and a high-pressure bottle 3 for storing high-pressure air. The contact gas detection device is generally set as a gas detector 10. The gas detector 10 is a mature instrument based on electrochemical sensors and semiconductors for detection. It has the advantages of being small and portable and having rapid detection. Of course, a gas chromatograph with the highest sensitivity and the most accurate quantitative analysis can also be used. Both the gas chromatograph and the gas detector 10 only need to inject the gas into the air inlet end to perform contact measurement, which will not be described in detail here; the non-contact gas detection device is set as an infrared spectrometer 5, an infrared The external spectrometer 5 generally adopts a Fourier transform infrared spectrometer. The infrared spectrometer 5 is a mature instrument that uses the absorption characteristics of infrared radiation of different wavelengths of a substance to analyze molecular structure and chemical composition. Its detection method is a prior art and will not be described in detail here. It should be noted that the gas chromatograph is expensive, large in size, and has a slow detection time. Although the infrared spectrometer 5 and the gas detector 10 are not as good as the gas chromatograph in terms of detection types and accuracy, they are better in portability and detection speed. The combination of the two can also make up for the lack of accuracy and diversity. The gas collection bottle 1, the gas collection sleeve 2 and the high-pressure bottle 3 are respectively provided with a first pressure gauge, a second pressure gauge and a third pressure gauge 301 for measuring the internal pressure; The gas collecting bottle 1 comprises a bottle body 101 and two bottlenecks 102 symmetrically arranged at both ends of the bottle body 101. The bottleneck 102 is made of hard material, and the bottle body 101 is made of a transparent heat-resistant material that can expand with the internal pressure. Specifically, the bottle body of the gas collecting bottle 1 is made of a transparent film-like polysiloxane, polytetrafluoroethylene, polycarbonate or polyimide material, etc., which has a certain flexibility or elasticity to meet the needs of gas collection and swelling to expand the volume, can reduce the pressure of the collected gas, ensure the stability of the gas, and because the temperature of the pyrolysis gas is relatively high, it meets the heat resistance requirements. At the same time, if it is necessary to directly use the infrared absorption spectrum measurement method to measure the type and concentration of the characteristic gas, it must also meet the transparent light transmission requirements; the external ports of the two bottlenecks 102 are respectively set as the air inlet and exhaust with a switch valve. The opening and closing of the air inlet and the air outlet can be controlled by two switch valves respectively, so as to collect characteristic gases and release characteristic gases after detection; the non-contact gas detection device performs gas detection corresponding to the bottle body 101; as needed, the infrared spectrometer 5 includes a support stand 501, and the upper and lower ends of the support stand 501 are respectively installed with corresponding light emitters 503 and detectors 502, and two cantilever rods 6 are symmetrically fixed on both sides of the middle part of the support stand 501, and the outer walls of the two bottlenecks 102 are respectively connected to the outer ends of the two cantilever rods 6, so that the gas collection bottle 1 can be supported and maintained between the light emitter 503 and the detector 502, so as to facilitate detection; in addition, the outer end of the cantilever rod 6 is installed with a card set corresponding to the bottleneck 102, and the card set is generally set as a quick-release clamp; The gas collection sleeve 2 includes a heat transfer sleeve section 201, through which the pyrolysis temperature is applied to the cable. Of course, a thermometer can be installed on the outer wall of the heat transfer sleeve section 201 for temperature measurement, thereby meeting the monitoring requirements of different test temperatures; as shown in the attached Figure 2 As shown, as needed, the central sleeve wall of the heat transfer sleeve section 201 is concave to form a heat conduction part 207 that contacts the cable, that is, it can directly heat up with open flame or electric heating from the heat conduction part 207, so as to transfer the temperature to the cable more quickly, simulate the ambient temperature, and cause it to pyrolyze; both ends of the heat transfer sleeve section 201 are connected with a heat insulation sleeve section 202. When the pyrolysis test temperature is high, the heat insulation sleeve section 202 can be used for insulation to prevent affecting the sealing effect of the two ends of the gas collecting sleeve 2 and causing the sealing clamp 4 to be too high in temperature and inconvenient to disassemble; as needed, the heat insulation sleeve section 202 is provided with an annular cavity 206 for storing pure water. Pure water has a large specific heat capacity and can absorb and isolate heat; the outer ends of the two heat insulation sleeve sections 202 are connected There is a transition sleeve section 203, and the outer end walls of the two transition sleeve sections 203 are both provided with a sealing clamp 4 for squeezing the transition sleeve section 203 tightly against the cable for sealing; according to needs, the outer end of the transition sleeve section 203 is reduced in diameter and set to rubber material, the sealing clamp 4 is set to a throat clamp, and two are arranged side by side along the axial interval of each transition sleeve section 203, and the inner wall of the outer end of the transition sleeve section 203 is provided with a plurality of convex tooth rings side by side along the axial direction, which greatly improves the sealing effect and prevents the characteristic gas from leaking out; the inner end walls of the two transition sleeve sections 203 are respectively provided with an inlet pipe 204 and an outlet pipe 205, and the inlet pipe 204 and the outlet pipe 205 are respectively located at the lower end and the higher end of the gas collecting sleeve 2, so that the cold gas of the intake air can push the hot gas of the pyrolysis upward for collection; The air inlet pipe 204 is connected to the bottle mouth of the high-pressure bottle 3 through a conduit with a control valve, and the air outlet pipe 205 is connected to the air inlet of the gas collecting bottle 1. The control valve and the switch valve can be set as manual regulating valves to manually control the switch and flow, and can also be set as automatic control valves. After the first pressure gauge, the second pressure gauge and the third pressure gauge 301 are set as pressure sensors at the same time, data feedback, monitoring and measurement, parameter setting and switch flow control can be performed by an additional controller at the same time, so as to achieve the effect of continuous automatic control; the gas discharged from the exhaust port of the gas collecting bottle 1 enters the cooler 9 through the connected pipeline for cooling, and is then introduced into the contact gas detection device for detection. The cooler 9 is set as a shell and tube heat exchanger, one end of the tube side is connected to the exhaust port of the gas collecting bottle 1, and the other end is connected to the air inlet end of the contact gas detection device. Cooling water is circulated in the shell side to cool the gas to prevent high temperature from interfering with the gas detector 10, causing equipment damage or inaccurate measurement.

[0019] The cable pyrolysis test equipment of the present invention comprises the following steps: Step 1: First, place the gas collection sleeve 2 outside the cable section to be pyrolyzed, then tighten the sealing clamp 4, and seal the two ends of the gas collection sleeve 2 against the cable; the initial pressure of the high-pressure air in the high-pressure bottle 3 is at least 3 times the atmospheric pressure; Step 2: Apply pyrolysis temperature to the cable through the heat transfer sleeve section 201 of the gas collecting sleeve 2; the specific pyrolysis temperature is determined according to the test requirements, and of course different temperatures can be set to collect tests and obtain different experimental data; Step 3, when the second pressure gauge measures the pressure change, while keeping the switch valve of the exhaust port of the gas collecting bottle 1 closed, open the switch valve of the gas inlet of the gas collecting bottle 1, and control the control valve of the high-pressure bottle 3 to adjust the pressure of the gas collecting sleeve 2 during the pyrolysis process to maintain 1 to 1.2 times the atmospheric pressure; under this limitation, the amount of characteristic gas generated is related to the duration of pyrolysis. If there are specific test requirements for the duration of pyrolysis, in order to achieve this time and keep the pressure, it is necessary to change the collection volume of the gas collecting bottle 1. In general, the pressure range is kept unchanged. The longer the pyrolysis test time required, the larger the volume of the gas collecting bottle 1 needs to be. If the pyrolysis test time is a fixed value, the volume of the gas collecting bottle 1 can also be determined; Step 4: When the pressure in the gas collection sleeve 2 reaches 1.2 times the atmospheric pressure, open the control valve of the high-pressure bottle 3, monitor the pressure changes of the second pressure gauge and the first pressure gauge, and when the pressure of the first pressure gauge reaches 1.5 times the atmospheric pressure, quickly close the switch valve of the gas inlet of the gas collection bottle 1 to complete the collection of characteristic gases; Step 5: Start the infrared spectrometer 5 to detect the characteristic gas in the bottle body 101; Step 6: After the infrared spectrometer 5 has finished detecting, the switch valve of the exhaust port of the gas collecting bottle 1 is opened, and the characteristic gas in the bottle body 101 is pressed out, cooled by the cooler 9, and then enters the gas detector 10 for secondary detection. Embodiment 2:

[0020] The difference from the first embodiment is that, if a direct ignition pyrolysis test is desired on the cable, an ignition unit corresponding to the cable can be installed on the middle wall of the heat transfer sleeve 201. Of course, during combustion, it is necessary to adjust the release of the high-pressure bottle 3 to provide the oxygen required for combustion. Embodiment three:

[0021] As attached Figure 3 As shown, in order to avoid manually squeezing the bottle body 101 for complete deflation, on the basis of the first embodiment, a telescopic cylinder 7 can be installed on the side of the gas collecting bottle 1 away from the supporting stand 501, and a squeezing plate 8 corresponding to the bottle body 101 is fixed to the telescopic rod end of the telescopic cylinder 7, thereby ensuring that after the exhaust port switch valve is opened, the telescopic rod 7 is controlled to push the squeezing plate 8 to move and squeeze the bottle body 101, and the characteristic gas in the bottle body 101 can be released more cleanly.

[0022] The parts of the present invention that are not described in detail are prior art. It is obvious to those skilled in the art that the present invention is not limited to the details of the above-mentioned exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, no matter from which point of view, the above-mentioned embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is limited by the attached claims rather than the above description. Therefore, it is intended to include all changes within the meaning and scope of the equivalent elements of the claims in the present invention, and any figure marks in the claims should not be regarded as limiting the content of the claims involved.

Claims

1. A cable pyrolysis test equipment, characterized by: The invention comprises a contact gas detection device, a non-contact gas detection device, a cooler (9), a gas collection bottle (1), a gas collection sleeve (2) sleeved outside a cable, and a high-pressure bottle (3) for storing high-pressure air, wherein the gas collection bottle (1), the gas collection sleeve (2) and the high-pressure bottle (3) are respectively provided with a first pressure gauge, a second pressure gauge and a third pressure gauge (301) for measuring internal pressure; the gas collection bottle (1) comprises a bottle body (101) and two bottlenecks (102) symmetrically arranged at both ends of the bottle body (101); the bottle body (101) is made of a transparent heat-resistant material capable of expanding with internal pressure; the external ports of the two bottlenecks (102) are respectively provided as an air inlet and an air outlet with a switch valve; the non-contact gas detection device performs gas detection corresponding to the bottle body (101); the gas collection sleeve (2) comprises a first pressure gauge (101) and a second pressure gauge (301) for measuring internal pressure; the gas collection bottle (1) comprises a first pressure gauge (101) and a second pressure gauge (301) for measuring internal pressure; the gas collection bottle (1) comprises a second pressure gauge (101) and a third pressure gauge (301) for measuring internal pressure; the gas collection bottle (1 ... The invention comprises a heat transfer sleeve section (201), both ends of the heat transfer sleeve section (201) are connected to a heat insulation sleeve section (202), the outer ends of the two heat insulation sleeve sections (202) are connected to a transition sleeve section (203), the outer end walls of the two transition sleeve sections (203) are clamped with a sealing clamp (4) for clamping the transition sleeve section (203) tightly against the cable for sealing, and the inner end walls of the two transition sleeve sections (203) are respectively provided with an air inlet pipe (204) and an air outlet pipe (205), the air inlet pipe (204) is correspondingly connected to the bottle mouth of the high-pressure bottle (3) through a conduit with a control valve, the air outlet pipe (205) is correspondingly connected to the air inlet of the air collecting bottle (1), and the gas discharged from the exhaust port of the air collecting bottle (1) enters the cooler (9) through the connected pipeline to reduce the temperature, and is then introduced into the contact gas detection device for detection.

2. The cable pyrolysis test equipment according to claim 1, characterized in that: The contact-type gas detection device is configured as a gas detector (10), and the non-contact-type gas detection device is configured as an infrared spectrometer (5).

3. The cable pyrolysis test equipment according to claim 2, characterized in that: The infrared spectrometer (5) comprises a supporting frame (501), the upper end and the lower end of the supporting frame (501) are respectively mounted with a light emitter (503) and a detector (502) corresponding to each other, two cantilever rods (6) are symmetrically fixed on both sides of the middle part of the supporting frame (501), and the outer walls of the two bottlenecks (102) are respectively connected to the outer ends of the two cantilever rods (6).

4. The cable pyrolysis test equipment according to claim 3, characterized in that: A telescopic cylinder (7) is installed on the side of the gas collecting bottle (1) away from the supporting stand (501), and a squeezing plate (8) corresponding to the bottle body (101) is fixed to the end of the telescopic rod of the telescopic cylinder (7).

5. The cable pyrolysis test equipment according to claim 1, characterized in that: An ignition unit corresponding to the cable is installed on the middle wall of the heat transfer sleeve section (201).

6. The cable pyrolysis test equipment according to claim 1, characterized in that: The central sleeve wall of the heat transfer sleeve section (201) is concave to form a heat conducting portion (207) that contacts the cable.

7. The cable pyrolysis test equipment according to claim 1, characterized in that: The heat-insulating sleeve section (202) is provided with an annular cavity (206) for storing pure water.

8. The cable pyrolysis test equipment according to claim 1, characterized in that: The outer end of the transition sleeve segment (203) is reduced in diameter and is made of rubber material. The sealing clamp (4) is a throat clamp, and two of them are arranged side by side at intervals along the axial direction of each transition sleeve segment (203). The inner wall of the outer end of the transition sleeve segment (203) is provided with a plurality of convex tooth rings side by side along the axial direction.

9. The cable pyrolysis test equipment according to claim 1, characterized in that: The air inlet pipe (204) and the air outlet pipe (205) are respectively located at the lower end and the upper end of the air collecting sleeve (2).

10. The cable pyrolysis test equipment according to claim 1, characterized in that: The body of the gas collecting bottle (1) is made of a transparent film-like material such as polysiloxane, polytetrafluoroethylene, polycarbonate or polyimide.

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