A temperature sensing cable made of a polymer material with a negative temperature coefficient and a method of using the same

Abstract

The present invention relates to a temperature-sensing cable made of a polymer material with a negative temperature coefficient and a method for using the same, belonging to the technical field of temperature-sensing fire detection cables, and comprising the following steps: Step 1): twisting a first temperature-sensing cable line and a second temperature-sensing cable line to form a temperature-sensing harness; Step 2): arranging the temperature-sensing harness in a location, connecting the two ends of the temperature-sensing harness to a signal processing device and a signal terminal respectively to form a complete temperature-sensing cable system, and using the temperature-sensing cable system to monitor environmental fires; The present invention has the following beneficial effects: the composition of the polymer material is improved, and the polymer material has a temperature-resistance characteristic on the basis of the original NTC characteristic or negative temperature coefficient characteristic of the polymer material, so that environmental fires can be easily detected.

Description

Technical Field

[0001] The present invention relates to the technical field of temperature-sensitive fire detection cables, and in particular to a temperature-sensitive cable made of a polymer material with a negative temperature coefficient and a use method thereof, which are applied to the detection and prevention of fires. Background Art

[0002] Fire is a vicious hazard that can take human life in an instant and endanger social undertakings and people's lives and property: Therefore, fire prevention is of great significance to promoting the modernization of Guihuifengyi and ensuring people's happy life. With the development of economy and science and technology, the causes of fires have become more complicated. Fires are no longer caused only by open flames. Mechanical friction, thermal effects of electricity, chemical exothermic reactions, release of nuclear energy, spontaneous combustion of materials, etc. can all lead to fires. How to prevent fires, discover them in time, deal with them quickly, and reduce material losses is the current primary issue. Therefore, it is necessary to use temperature-sensitive fire detection cables to detect the temperature of installed cables in order to reduce or eliminate the occurrence of cable fires. In the prior art, analog linear temperature-sensitive fire detection cables containing NTC material layers are commonly used, which are widely used fire detection cables.

[0003] NTC characteristic is negative temperature coefficient characteristic, that is, the resistance decreases as the temperature increases, and the temperature coefficient α T Indicates how fast the resistance of a material changes with temperature, α T Usually between -0.1% and -40%. When the NTC material layer is heated, as the temperature rises, the resistance between the two detection conductors will decrease, and a linear constant temperature or differential temperature fire detection cable will be formed according to the absolute value of the resistance change or the change rate, thereby achieving the purpose of temperature measurement and fire alarm.

[0004] Traditional negative temperature coefficient (NTC) materials are metal ceramic materials, which are not easy to process. Now it is necessary to make a new type of polymer material with negative temperature coefficient for use as a temperature sensing cable, which can solve the problem that the NTC characteristics or negative temperature coefficient characteristics of polymer materials have temperature-resistance characteristics, and can be conveniently used in fire detection and prevention. Summary of the invention

[0005] The technical problem to be solved by the present invention is that the NTC characteristic or negative temperature coefficient characteristic of the polymer material does not have the temperature-resistance characteristic. The present invention provides a temperature-sensing cable of a polymer material with a negative temperature coefficient and a method for using the same, improves the composition of the polymer material, and enables the polymer material to have the temperature-resistance characteristic on the basis of the original NTC characteristic or negative temperature coefficient characteristic of the polymer material, thereby conveniently detecting environmental fires.

[0006] In order to achieve the above object, the present invention is implemented by the following technical solutions:

[0007] A temperature sensing cable made of a polymer material with a negative temperature coefficient, comprising:

[0008] A first temperature-sensing cable, wherein the first temperature-sensing cable has an elastic stainless steel wire, the elastic stainless steel wire is coated with a conductive plastic, and the conductive plastic is coated with an insulating protective net;

[0009] A second temperature-sensitive cable, wherein the second temperature-sensitive cable comprises the elastic stainless steel wire, the elastic stainless steel wire is coated with a polymer material layer on the outside, and the polymer material layer is an NTC material;

[0010] The first temperature-sensing cable and the second temperature-sensing cable are twisted into a temperature-sensing wiring harness, one end of the temperature-sensing wiring harness is coated with an aluminum foil composite layer, the outside of the aluminum foil composite layer is coated with a plastic protective layer, one end of the temperature-sensing wiring harness passes through the aluminum foil composite layer and is connected to a signal processing device, and the other end of the temperature-sensing wiring harness is connected to a signal terminal.

[0011] Optionally, the polymer material layer is a composite material made of styrene-ethylene-butadiene-styrene copolymer, ethylene-vinyl acetate, polyvinyl chloride and high-density polyethylene in proportions, and the composite material is used as the substrate;

[0012] The wire diameter of the elastic stainless steel wire ranges from 0.6mm to 0.9mm, and the material of the elastic stainless steel wire is 304H.

[0013] Optionally, the ratios of the styrene-ethylene-butadiene-styrene copolymer, ethylene-vinyl acetate, polyvinyl chloride and high-density polyethylene are 1-10 parts: 1-10 parts: 1-10 parts: 1-10 parts respectively.

[0014] Optionally, a metal material with conductive properties, a carbon nanotube, a conductive graphite and a graphene material are added to the composite material in a ratio of 1-10 parts: 1-10 parts: 1-10 parts: 1-10 parts respectively to prepare the polymer material layer with NTC characteristics.

[0015] Optionally, the polymer material layer of the NTC characteristic is made into a thin sheet with a thickness of 0.5-1.5 mm by vulcanization and pressing, and the thin sheet is used to measure the temperature-resistance characteristic of the NTC characteristic.

[0016] A method for using a temperature-sensing cable made of a polymer material with a negative temperature coefficient comprises the following steps:

[0017] Step 1): twisting the first temperature sensing cable and the second temperature sensing cable to form a temperature sensing harness;

[0018] Step 2): Arrange the temperature sensing harness in the place, connect the two ends of the temperature sensing harness to the signal processing device and the signal terminal respectively to form a complete temperature sensing cable system, and use the temperature sensing cable system to monitor the environmental fire.

[0019] Further, in step 2), the use of the temperature sensing cable system adopts the following steps:

[0020] Step 21): Input 24V voltage to the temperature sensing cable system to detect the resistance change of the temperature sensing harness in the place in real time;

[0021] Step 22): When a fire occurs in the environment around the temperature sensing harness, the temperature of the environment around the temperature sensing harness will rise, and the conductive plastic on the first temperature sensing cable will melt and expand due to the temperature rise, and the conductive plastic will contact the polymer material layer on the second temperature sensing cable through the insulating protection net woven from polyester monofilaments;

[0022] Step 23): As the temperature of the conductive plastic increases, the resistance of the polymer material layer decreases, and the polymer material layer gradually changes from an insulating state to a conductive state;

[0023] Step 24): After the conductive polymer material layer contacts the conductive plastic, the resistance between the two copper wires decreases, a short circuit is formed between the first temperature sensing cable and the second temperature sensing cable, the detection signal of the temperature sensing cable system changes, and an alarm signal is issued.

[0024] The temperature sensing cable system is used in the following manner:

[0025] When no fire occurs in the environment around the temperature sensing wiring harness, the temperature of the environment around the temperature sensing wiring harness decreases, the conductive plastic retracts into the insulating protective net, the conductive plastic does not contact the polymer material layer, and the polymer material layer is insulated, the resistance of the polymer material layer increases, the resistance between the two copper wires increases, the first temperature sensing cable line and the second temperature sensing cable line are insulated, the detection signal of the temperature sensing cable system returns to normal, and no alarm signal is issued.

[0026] Beneficial effects of the present invention:

[0027] 1. The present invention adds styrene-ethylene-butadiene-styrene copolymer, ethylene-vinyl acetate, polyvinyl chloride and high-density polyethylene into the polymer material layer in proportion to manufacture a composite material. The composite material satisfies the original NTC characteristics or negative temperature coefficient characteristics of the polymer material and enables the polymer material to have temperature-resistance characteristics.

[0028] 2. The present invention utilizes the expansion and contraction of the conductive plastic in a temperature environment, and the temperature-resistance characteristics of the polymer material layer in a temperature environment; that is, the conductive plastic expands when the temperature rises and contacts the polymer material layer, the temperature of the polymer material layer rises, the resistance of the polymer material layer decreases, and a short circuit occurs between the conductive plastic and the polymer material layer; the conductive plastic contracts when the temperature drops and separates from the polymer material layer, the temperature of the polymer material layer decreases, the resistance of the polymer material layer increases, and the conductive plastic and the polymer material layer are insulated, thereby facilitating the detection of environmental fires. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 The temperature-resistance characteristic curve of the traditional negative temperature polymer composite material to be obtained;

[0031] Figure 2 This is the temperature-resistance characteristic curve of the traditional negative temperature polymer composite material;

[0032] Figure 3 It is a product structure diagram of the present invention;

[0033] Figure 4 A schematic diagram of a sample for testing the temperature-resistance characteristics of a negative temperature coefficient polymer composite material of the present invention;

[0034] Figure 5 A temperature-resistance characteristic data diagram of a negative temperature coefficient polymer composite material according to an embodiment of the present invention;

[0035] Figure 6 This is a temperature-resistance characteristic data diagram of a negative temperature coefficient polymer composite material according to another embodiment of the present invention.

[0036] Icon: 1-first temperature sensing cable, 2-elastic stainless steel wire, 3-conductive plastic, 4-insulating protection net, 5-second temperature sensing cable, 6-polymer material layer, 7-aluminum foil composite layer, 8-plastic protective layer. DETAILED DESCRIPTION

[0037] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0038] Example 1

[0039] The basic structure of analog temperature sensing cable based on negative temperature coefficient polymer material is to twist two elastic conductors coated with negative temperature coefficient polymer layer together with a certain twist distance, and cover the outer sheath. Its working principle is that at room temperature or lower temperature, the resistance between the elastic conductors of the two polymer layers is maintained at a higher value. When the temperature rises to near the operating temperature, the resistance of the polymer material of the elastic conductor of the negative temperature coefficient polymer layer decreases, so that the resistance between the elastic conductors of the two polymer layers decreases to a certain value. The negative temperature coefficient polymer material has this temperature-resistance characteristic, and the signal detection device can control the equipment through this change.

[0040] According to the above working principle, the negative temperature coefficient polymer material used for temperature sensing cable should have the following characteristics: Figure 1 The temperature-resistance characteristic shown in the figure means that before the operating temperature, the resistance of the material changes little (no change is ideal), and when the temperature rises to near the operating temperature, the resistance of the material decreases exponentially. The temperature sensing cable made of this material can provide a sensitive alarm signal and is less affected by the ambient temperature or is basically unaffected. However, negative temperature coefficient polymer materials usually do not have temperature-resistance characteristics. Figure 2 The negative temperature coefficient polymer material shown has a temperature-resistance characteristic, that is, at room temperature or lower temperature, the resistance decreases more with temperature, but when it reaches near the operating temperature, the resistance change is smaller. However, the alarm sensitivity of the analog linear temperature sensing cable prepared using this negative temperature polymer composite material is poor and is greatly affected by the ambient temperature.

[0041] Example 2

[0042] Based on Example 1, Figure 3 As shown, this embodiment is improved compared with embodiment 1. This embodiment provides a temperature-sensing cable made of a polymer material with a negative temperature coefficient, including: a first temperature-sensing cable 1 and a second temperature-sensing cable 5. The first temperature-sensing cable 1 has an elastic stainless steel wire 2, and the elastic stainless steel wire 2 is coated with a conductive plastic 3 on the outside. The conductive plastic 3 (a functional polymer material processed by mixing resin and conductive material and processing in a plastic processing method) is coated with an insulating protective net 4 on the outside. The second temperature-sensing cable 5 has the elastic stainless steel wire 2, and the elastic stainless steel wire 2 is coated with a polymer material layer 6 on the outside. The polymer material layer 6 is an NTC material. The wire diameter of the elastic stainless steel wire 2 ranges from 0.6 mm to 0.9 mm. The material of the elastic stainless steel wire 2 is 304H, and the elastic stainless steel wire 2 is used as a conductive wire.

[0043] The first temperature sensing cable 1 and the second temperature sensing cable 5 are twisted into a temperature sensing harness. One end of the temperature sensing harness is coated with an aluminum foil composite layer 7, which serves as an anti-signal interference layer. The outside of the aluminum foil composite layer 7 is coated with a plastic protective layer 8, which serves as a protective aluminum foil composite layer 7. One end of the temperature sensing harness passes through the aluminum foil composite layer 7 and is connected to a signal processing device. One end of the temperature sensing harness is connected to a temperature sensor, and the other end of the temperature sensing harness is connected to a signal terminal, that is, the other end of the temperature sensing harness is connected to an alarm.

[0044] based on Figure 1 According to the principle, in order to improve the temperature-resistance characteristics of the negative temperature coefficient polymer material, the polymer material layer 6 is a composite material made of styrene-ethylene-butadiene-styrene copolymer (SEBS), ethylene-vinyl acetate (EVA), polyvinyl chloride (PVC) and high-density polyethylene (HDPE) in proportion, and the composite material is used as the substrate, that is, the proportion of styrene-ethylene-butadiene-styrene copolymer, ethylene-vinyl acetate, polyvinyl chloride and high-density polyethylene is 1~10 parts: 1~10 parts: 1~10 parts: 1~10 parts. When the temperature of the composite material with olefins changes, the polymer chain segments inside the material move, changing the electrical properties of the material itself, thereby obtaining the temperature-resistance characteristics we need.

[0045] Metal materials with conductive properties (such as iron, copper and aluminum, etc.), carbon nanotubes, conductive graphite and graphene materials can be added to the composite material as functional materials in a ratio of 1~10 parts: 1~10 parts: 1~10 parts: 1~10 parts respectively to prepare a polymer material layer 6 with NTC characteristics. The polymer material layer 6 with NTC characteristics can further obtain temperature-resistance characteristics.

[0046] Therefore, the polymer material layer 6 of this embodiment is relatively Figure 1 In general, it has the temperature-resistance characteristics of polymer materials with negative temperature coefficient.

[0047] Example 3

[0048] Based on Example 2, and Figure 3 As shown, this embodiment provides a method for using a temperature sensing cable made of a polymer material with a negative temperature coefficient, comprising the following steps:

[0049] Step 1): twisting the first temperature sensing cable 1 and the second temperature sensing cable 5 to form a temperature sensing harness;

[0050] Step 2): Arrange the temperature sensing harness in the place, connect the two ends of the temperature sensing harness to the signal processing device and the signal terminal respectively to form a complete temperature sensing cable system, and use the temperature sensing cable system to monitor the environmental fire.

[0051] The use of the temperature sensing cable system adopts the following steps:

[0052] Step 21): Input 24V voltage to the temperature sensing cable system to detect the resistance change of the temperature sensing harness in the place in real time;

[0053] Step 22): When a fire occurs in the environment around the temperature sensing harness, the temperature of the environment around the temperature sensing harness will rise, and the conductive plastic 3 on the first temperature sensing cable 1 will melt and expand due to the temperature rise, and the conductive plastic 3 will contact the polymer material layer 6 on the second temperature sensing cable 5 through the insulating protection net 4 woven from polyester monofilaments;

[0054] The industrial use of polyester monofilament is mainly used for weaving filter screens, Meiji mesh cloths, rubber wire external sleeves, etc. Among them, the filter screen woven from polyester monofilament has the functions of high strength, good elasticity, good wear resistance and good light resistance. Therefore, the insulating protection net 4 woven from polyester monofilament has elastic contraction function;

[0055] Step 23): As the temperature of the conductive plastic 3 increases, the resistance of the polymer material layer 6 decreases, and the polymer material layer 6 gradually changes from an insulating state to a conductive state;

[0056] Step 24): After the conductive polymer material layer 6 contacts the conductive plastic 3, the resistance between the two copper wires 2 decreases, a short circuit is formed between the first temperature sensing cable 1 and the second temperature sensing cable 5, the detection signal of the temperature sensing cable system changes, and an alarm signal is issued.

[0057] When no fire occurs in the environment around the temperature sensing harness, the temperature of the environment around the temperature sensing harness decreases, the conductive plastic 3 is retracted into the insulating protection net 4, the conductive plastic 3 is not in contact with the polymer material layer 6, and the polymer material layer 6 is in an insulating state, the resistance of the polymer material layer 6 increases, the resistance between the two copper wires 2 increases, the first temperature sensing cable line 1 and the second temperature sensing cable line 5 are insulated, the detection signal of the temperature sensing cable system returns to normal, and no alarm signal is issued.

[0058] It can be seen from this embodiment that when a fire occurs in the environment around the temperature sensing harness, the temperature of the environment around the temperature sensing harness will increase, and the conductive plastic 3 contacts the polymer material layer 6 on the second temperature sensing cable 5 through the insulating protection net 4, and the resistance of the polymer material layer 6 decreases, and the polymer material layer 6 gradually tends from an insulating state to a conductive state. After the conductive polymer material layer 6 contacts the conductive plastic 3, the resistance between the two copper wires 2 becomes smaller, a short circuit is formed between the first temperature sensing cable 1 and the second temperature sensing cable 5, and the detection signal of the temperature sensing cable system changes, and an alarm signal is issued; when no fire occurs in the environment around the temperature sensing harness, the temperature of the environment around the temperature sensing harness decreases, the conductive plastic 3 does not contact the polymer material layer 6, the resistance of the polymer material layer 6 increases, the resistance between the two copper wires 2 increases, the first temperature sensing cable 1 and the second temperature sensing cable 5 are insulated, and the detection signal of the temperature sensing cable system returns to normal, and no alarm signal is issued.

[0059] Example 4

[0060] Based on Example 2, Figure 4 As shown, the thin film of the polymer material layer 6 with NTC characteristics is made and tested as follows:

[0061] 1. Add SEBS, PVC and HDPE into a mixer in a certain proportion, set the temperature to 160°C and mix at 60 rpm for 120 minutes.

[0062] 2. Add the conductive material (metal powder) into the internal mixer in a certain proportion and mix for 30 minutes.

[0063] 3. Lower the temperature of the internal mixer to 90°C, add the EVA weighed in advance, and mix for 50 minutes.

[0064] 4. Reduce the temperature of the internal mixer to 40°C, add dicumyl peroxide (DCP) in proportion, and mix for 20 minutes.

[0065] 5. Take out the material and use a flat vulcanizer to press the composite material into a 1mm thick sheet (vulcanization temperature 160℃, vulcanization time 30 minutes), and press two copper sheets into it as electrodes, with a distance of 1cm between the two electrodes ( Figure 3 ). Connect the two probes of the multimeter to the two electrodes, put them in the oven, and use a thermometer to monitor the temperature.

[0066] In this way, the polymer material layer 6 of the NTC characteristic is made into a thin sheet with a thickness of 1 mm by vulcanization and pressing, and the thin sheet is used to measure the temperature-resistance characteristic of the NTC characteristic.

[0067] Example 5

[0068] Specifically, based on Example 2, Figure 5As shown, the polymer material layer 6 is made as follows:

[0069] 1. Weigh 500 g of SEBS, 200 g of PVC, and 150 g of HDPE, add them into an internal mixer, set the temperature to 160°C, and mix at 60 rpm for 120 minutes.

[0070] 2. Weigh 100 g of metal powder and 25 g of graphene powder and add them into an internal mixer in a certain proportion, and mix for 30 minutes.

[0071] 3. Lower the temperature of the internal mixer to 90°C, weigh 150g of EVA, and mix for 50 minutes.

[0072] 4. Reduce the temperature of the internal mixer to 40°C, add 15 g of dicumyl peroxide (DCP), and mix for 20 minutes.

[0073] 5. Take out the material and use a flat vulcanizer to press the composite material into a thin sheet with a thickness of 1 mm (vulcanization temperature 160°C, vulcanization time 30 minutes), and test the temperature-resistance characteristics of the sample material.

[0074] based on Figure 1 The principle, Figure 5 The improvement is, Figure 5 When the polymer material layer 6 is in a specified temperature range, i.e., a temperature range below 90°C, when the temperature of the polymer material layer 6 increases, the resistance value of the polymer material layer 6 increases appropriately; when the polymer material layer 6 is in a specified temperature range, i.e., above 90°C, when the temperature of the polymer material layer 6 increases, the resistance value of the polymer material layer 6 decreases, satisfying the NTC characteristics or negative temperature coefficient characteristics of the polymer material with temperature-resistance characteristics.

[0075] Example 6

[0076] Based on Example 2, Figure 6 As shown, the polymer material layer 6 is made as follows:

[0077] 1. Weigh 450g of SEBS, 250g of PVC and 100g of HDPE, add them into an internal mixer, set the temperature to 160°C and mix at 60rpm for 120 minutes.

[0078] 2. Weigh 30 g of metal powder, 70 g of conductive graphite and 20 g of graphene powder, add them into an internal mixer in a certain proportion, and mix for 30 minutes.

[0079] 3. Lower the temperature of the internal mixer to 90°C, weigh 200g of EVA, and mix for 50 minutes.

[0080] 4. Reduce the temperature of the internal mixer to 40°C, add 15 g of dicumyl peroxide (DCP), and mix for 20 minutes.

[0081] 5. Take out the material and use a flat vulcanizer to press the composite material into a thin sheet with a thickness of 1 mm (vulcanization temperature 160°C, vulcanization time 30 minutes), and test the temperature-resistance characteristics of the sample material.

[0082] based on Figure 1 The principle, Figure 6 The improvement is, Figure 6 When the polymer material layer 6 is in a specified temperature range, i.e., a temperature range below 90°C, when the temperature of the polymer material layer 6 increases, the resistance value of the polymer material layer 6 increases appropriately; when the polymer material layer 6 is in a specified temperature range, i.e., above 90°C, when the temperature of the polymer material layer 6 increases, the resistance value of the polymer material layer 6 decreases, satisfying the NTC characteristics or negative temperature coefficient characteristics of the polymer material with temperature-resistance characteristics.

[0083] Example 7

[0084] It can be seen from all the above embodiments that the improvements of the present invention are:

[0085] 1. The material composition of the polymer material layer 6 is improved so that the negative temperature coefficient polymer material has this temperature-resistance characteristic.

[0086] 2. Utilize the expansion and contraction of the conductive plastic 3 in a temperature environment, and the temperature-resistance characteristics of the polymer material layer 6 in a temperature environment; that is, when the conductive plastic 3 is heated up and expands, and contacts the polymer material layer 6, the temperature of the polymer material layer 6 increases, the resistance of the polymer material layer 6 decreases, and a short circuit occurs between the conductive plastic 3 and the polymer material layer 6; when the conductive plastic 3 is cooled and contracts, and separates from the polymer material layer 6, the temperature of the polymer material layer 6 decreases, the resistance of the polymer material layer 6 increases, and the conductive plastic 3 and the polymer material layer 6 are insulated.

[0087] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope recorded in the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A temperature sensing cable made of a polymer material with a negative temperature coefficient, characterized in that: include: A first temperature-sensing cable (1), the first temperature-sensing cable (1) comprising an elastic stainless steel wire (2), the elastic stainless steel wire (2) being coated with a conductive plastic (3), the conductive plastic (3) being coated with an insulating protective net (4), the conductive plastic (3) being a mixture of resin and conductive material, and being a functional polymer material processed in a plastic processing manner; A second temperature-sensing cable (5), wherein the second temperature-sensing cable (5) comprises the elastic stainless steel wire (2), the elastic stainless steel wire (2) is coated with a polymer material layer (6) on the outside, the polymer material layer (6) is an NTC material, the polymer material layer (6) is a composite material made of styrene-ethylene-butadiene-styrene copolymer, ethylene-vinyl acetate, polyvinyl chloride and high-density polyethylene in proportion, the composite material is used as a substrate, the wire diameter of the elastic stainless steel wire (2) ranges from 0.6 mm to 0.9 mm, and the elastic stainless steel wire (2) is made of 304H material; Wherein, the ratios of styrene-ethylene-butadiene-styrene copolymer, ethylene-vinyl acetate, polyvinyl chloride and high-density polyethylene are 1-10 parts: 1-10 parts: 1-10 parts: 1-10 parts respectively; Adding a metal material having conductive properties, a carbon nanotube, a conductive graphite and a graphene material to the composite material in a ratio of 1-10 parts: 1-10 parts: 1-10 parts: 1-10 parts respectively, to prepare the polymer material layer (6) having NTC properties; A first temperature-sensing cable (1) and a second temperature-sensing cable (5) are twisted into a temperature-sensing harness, one end of the temperature-sensing harness is coated with an aluminum foil composite layer (7), the outside of the aluminum foil composite layer (7) is coated with a plastic protective layer (8), one end of the temperature-sensing harness passes through the aluminum foil composite layer (7) and is connected to a signal processing device, and the other end of the temperature-sensing harness is connected to a signal terminal.

2. The temperature sensing cable made of a polymer material with a negative temperature coefficient according to claim 1, characterized in that: The NTC characteristic polymer material layer (6) is made into a thin sheet with a thickness of 0.5-1.5 mm by vulcanization and pressing, and the thin sheet is used to measure the temperature-resistance characteristic of the NTC characteristic.

3. A method for using a temperature-sensing cable made of a polymer material with a negative temperature coefficient, using a temperature-sensing cable made of a polymer material with a negative temperature coefficient according to any one of claims 1-2, characterized in that: The steps include: Step 1): twisting a first temperature sensing cable (1) and a second temperature sensing cable (5) to form a temperature sensing cable harness; Step 2): Arrange the temperature sensing harness in the place, connect the two ends of the temperature sensing harness to the signal processing device and the signal terminal respectively to form a complete temperature sensing cable system, and use the temperature sensing cable system to monitor the environmental fire.

4. The method for using a temperature-sensing cable made of a polymer material with a negative temperature coefficient according to claim 3, characterized in that: In step 2), the temperature sensing cable system is used by the following steps: Step 21): Input 24V voltage to the temperature sensing cable system to detect the resistance change of the temperature sensing harness in the place in real time; Step 22): When a fire occurs in the environment around the temperature sensing harness, the temperature of the environment around the temperature sensing harness will rise, and the conductive plastic (3) on the first temperature sensing cable (1) will melt and expand due to the temperature rise, and the conductive plastic (3) will contact the polymer material layer (6) on the second temperature sensing cable (5) through the insulating protection net (4) woven from polyester monofilaments; Step 23): As the temperature of the conductive plastic (3) increases, the resistance of the polymer material layer (6) decreases, and the polymer material layer (6) gradually changes from an insulating state to a conductive state; Step 24): After the conductive polymer material layer (6) contacts the conductive plastic (3), the resistance between the two copper wires (2) decreases, a short circuit is formed between the first temperature sensing cable (1) and the second temperature sensing cable (5), the detection signal of the temperature sensing cable system changes, and an alarm signal is issued.

5. The method for using a temperature-sensing cable made of a polymer material with a negative temperature coefficient according to claim 3, characterized in that: In the step 2), the temperature sensing cable system is used in the following manner: When no fire occurs in the environment around the temperature sensing harness, the temperature of the environment around the temperature sensing harness decreases, the conductive plastic (3) is retracted into the insulating protection net (4), the conductive plastic (3) is not in contact with the polymer material layer (6), and the polymer material layer (6) is in an insulating state, the resistance of the polymer material layer (6) increases, the resistance between the two copper wires (2) increases, the first temperature sensing cable (1) and the second temperature sensing cable (5) are insulated, the detection signal of the temperature sensing cable system returns to normal, and no alarm signal is issued.

Images