Metal armored safe heating cable and control cabinet

Abstract

The utility model relates to a metal armored safe heating cable and a control cabinet, the metal armored safe heating cable is used in an oil gas transmission pipeline, and the metal armored safe heating cable comprises a conductive outer armor and a conductive core wire; an insulating layer is arranged between the conductive outer armor and the conductive core wire, and the insulating layer is made of a single-layer or multi-layer oil-resistant and high-temperature-resistant material; wherein the insulating layer comprises an oil-resistant insulating layer and a high-temperature-resistant insulating layer; the oil-resistant insulating layer comprises oil-resistant nitrile or oil-resistant silica gel; and the high-temperature-resistant insulating layer comprises a mica braid layer. The insulating layer of the metal armored safe heating cable adopts the oil-resistant insulating layer and the high-temperature-resistant insulating layer which are matched with each other, so that the metal armored safe heating cable can resist high temperature and is high in oil resistance and long in service life.

Description

Technical Field

[0001] The present application relates to the field of cable technology, and in particular to a metal armored safety heating cable and a control cabinet. Background Art

[0002] The pipeline skin effect electric heating technology is a new metal pipeline heating method that has emerged in recent years. It is a new technology for heating and heat preservation of heat transmission pipelines in large petrochemical and other enterprises. This heating technology has high efficiency and is suitable for heating and heating of all long, medium and short distance metal liquid transmission pipelines. It is safe and reliable, has a long service life, and is easy to install and maintain. Therefore, it is widely used in pipeline heating of various liquid substances of different properties.

[0003] The current skin-collecting heating cables usually have the following structure: a conductor, which is a wire drawn from a copper rod; an insulating layer that wraps the conductor, which is usually made of a polypropylene insulating layer or an EPDM rubber insulating layer; and a sheath layer, which is usually made of carbon steel material with a more obvious skin effect.

[0004] The above prior art has the following problems:

[0005] The polypropylene (PP) insulation layer is a thermoplastic plastic, which is suitable for use in an environment of -20-100°C. Polypropylene is brittle at low temperatures and easily aged and deformed at high temperatures. EPDM rubber insulation is a widely used thermosetting resin material. It has good insulation properties and can work for a long time in an environment of -40-180°C, but EPDM rubber has poor oil resistance. Therefore, the insulation layer of the skin-collecting heating cable in the prior art has poor high temperature and oil resistance and a short service life.

[0006] Therefore, there is an urgent need to provide a metal armored safety heating cable and a control cabinet to solve the above-mentioned technical problems. Utility Model Content

[0007] Based on this, a metal armored safety heating cable and control cabinet are provided. The insulation layer is made of oil-resistant nitrile or oil-resistant silicone and a mica braided layer. It can withstand high temperature and oil resistance and has a long service life.

[0008] On the one hand, a metal armored safety heating cable is provided for use in an oil and gas pipeline, wherein the metal armored safety heating cable comprises: a conductive outer armor and a conductive core wire; an insulating layer is arranged between the conductive outer armor and the conductive core wire, and the insulating layer is arranged to be made of a single layer or multiple layers of oil-resistant and high-temperature resistant materials; wherein the insulating layer comprises an oil-resistant insulating layer and a high-temperature resistant insulating layer; the oil-resistant insulating layer comprises oil-resistant nitrile or oil-resistant silicone; the high-temperature resistant insulating layer comprises a mica braided layer.

[0009] A preferred solution is: the conductive outer armor, the high temperature resistant insulating layer, the oil resistant insulating layer and the conductive core wire constitute a heating cable; one end of the conductive outer armor and the conductive core wire are respectively connected to the positive and negative poles of the control cabinet, and the other ends of the conductive outer armor and the conductive core wire are short-circuited with each other through a wire.

[0010] On the other hand, a control cabinet is also provided, comprising the above-mentioned metal armored safety heating cable, and the control cabinet adopts external industrial alternating current or solar photovoltaic panels and energy storage devices as power sources.

[0011] A preferred solution is that the output power supply of the control cabinet is configured with an isolation transformer and a constant current output controller whose positions are interchangeable; the conductive outer armor and the conductive core wire are respectively connected to the isolation transformer or the constant current output controller through wires.

[0012] A preferred solution is: the cross-sectional area of ​​the heating cable is set to a first threshold; the heating cable is in a first state when the damaged area reaches 0-25% of the first threshold; and the control cabinet is a normal cabinet when the heating cable is in the first state.

[0013] A preferred solution is that: the heating cable is in the second state when the damaged area reaches 25% of the first threshold; and the control cabinet is an abnormal cabinet when the heating cable is in the second state.

[0014] A preferred solution is: the cross-sectional area of ​​the heating cable is set to a first threshold; the heating cable is in a third state when the damaged area reaches 0-75% of the first threshold; and the control cabinet is an abnormal cabinet when the heating cable is in the third state.

[0015] A preferred solution is that: the heating cable is in the fourth state when the damaged area reaches 75% of the first threshold; and the control cabinet is an abnormal cabinet when the heating cable is in the fourth state.

[0016] A better solution is: the cross-sectional area of ​​the heating cable is set to a first threshold; the heating cable is in the fifth state when the damaged area reaches 75%-100% of the first threshold; and the control cabinet is an abnormal cabinet when the heating cable is in the fifth state.

[0017] A preferred solution is that: when the damaged area of ​​the heating cable reaches 100% of the first threshold value, it is in the sixth state; and the control cabinet is an abnormal cabinet when the heating cable is in the sixth state.

[0018] Beneficial effects:

[0019] The above-mentioned metal armored safety heating cable and control cabinet, the metal armored safety heating cable is used in the oil and gas pipeline, and has an oil-resistant insulation layer and a high-temperature resistant insulation layer between the conductive outer armor and the conductive core wire. The oil-resistant insulation layer is made of oil-resistant nitrile or oil-resistant silicone. This material has good oil resistance and the oil resistance temperature can adapt to temperatures above 170 degrees. The high-temperature resistant insulation layer is made of mica braided layer. This material has excellent high-temperature resistant insulation performance and has good cost performance among high-temperature resistant insulation materials. Therefore, the insulation layer of the skin-heating cable has good high-temperature and oil resistance and a long overall service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the structure of a metal armored safety heating cable in one embodiment;

[0021] Figure 2 is a schematic diagram of a control cabinet in one embodiment;

[0022] Figure 3 A schematic diagram of the flow direction of current when the metal armored safety heating cable is intact in one embodiment;

[0023] Figure 4 A schematic diagram of the flow direction of current when the metal armored safety heating cable is damaged by 0-25% in one embodiment;

[0024] Figure 5 A schematic diagram of the flow of current when the metal armored safety heating cable is damaged by 25% in one embodiment;

[0025] Figure 6 A schematic diagram of the flow of current when the metal armored safety heating cable is damaged by 0-75% in one embodiment;

[0026] Figure 7 A schematic diagram of the flow of current when the metal armored safety heating cable is damaged by 75% in one embodiment;

[0027] Figure 8 A schematic diagram of the flow of current when the metal armored safety heating cable is damaged by 75%-100% in one embodiment;

[0028] Fig. 9 It is a schematic diagram of the flow of current when the metal armored safety heating cable is 100% damaged in one embodiment.

[0029] Figure numerals: 1. conductive outer armor; 2. high temperature resistant insulating layer; 3. oil resistant insulating layer; 4. conductive core wire; 5. control cabinet. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0031] It should be noted that the illustrations provided in this embodiment only illustrate the basic concept of the present application in a schematic manner, and therefore the drawings only show components related to the present application rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0032] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with this technology. They are not used to limit the conditions under which this application can be implemented, and therefore have no substantive technical significance. Any structural modification, change in proportion or adjustment of size, without affecting the effects and purposes that can be achieved by this application, should still fall within the scope of the technical contents disclosed in this application.

[0033] The directions or positional relationships indicated by the terms "upper", "lower", "left", "right", "middle", "longitudinal", "lateral", "horizontal", "inner", "outer", "radial", "circumferential" and the like in this specification are based on the directions or positional relationships shown in the drawings and are only for the convenience of simplifying the description. They do not indicate or imply that the devices or elements referred to must have a specific direction, be constructed and operate in a specific direction, and therefore cannot be understood as limiting the present application. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0034] The following is a detailed description of a metal armored safety heating cable and a control cabinet provided in this embodiment. The metal armored safety heating cable in this embodiment is used in an oil and gas pipeline, such as Figure 1 As shown, it includes: a conductive outer armor 1 and a conductive core wire 4, an insulating layer is arranged between the conductive outer armor 1 and the conductive core wire 4, and the insulating layer is arranged to be made of a single layer or multiple layers of oil-resistant and high-temperature resistant materials; wherein, the insulating layer includes an oil-resistant insulating layer 3 and a high-temperature resistant insulating layer 2; the oil-resistant insulating layer 3 includes oil-resistant nitrile or oil-resistant silicone; the high-temperature resistant insulating layer 2 includes a mica braided layer.

[0035] In this embodiment, an insulating layer is arranged between the conductive outer armor 1 and the conductive core wire 4, and the insulating layer adopts an oil-resistant insulating layer 3 and a high-temperature resistant insulating layer 2 to cooperate with each other. The oil-resistant insulating layer 3 selects oil-resistant nitrile or oil-resistant silicone. This material has good oil resistance and the oil resistance temperature can adapt to temperatures above 170 degrees. The high-temperature resistant insulating layer 2 selects a mica braided layer. This material has excellent high-temperature resistant insulation performance and has good cost performance among high-temperature resistant insulating materials. Therefore, the insulating layer of the metal armored safety heating cable in this embodiment has good high-temperature and oil resistance and a long overall service life.

[0036] In this embodiment, it should be noted that the conductive outer armor 1, the high temperature resistant insulating layer 2, the oil resistant insulating layer 3 and the conductive core wire 4 constitute a heating cable. The heating cable has excellent electrical properties of oil resistance, high temperature resistance, high pressure resistance, corrosion resistance and high strength, and is particularly suitable for high temperature and high pressure oil pipelines and oil extraction pipelines. When in use, one end of the conductive outer armor 1 and the conductive core wire 4 are respectively connected to the positive and negative poles of the control cabinet, and the other ends of the conductive outer armor 1 and the conductive core wire 4 are short-circuited with each other through a wire, thereby forming a loop. The heating cable is designed based on the skin effect. According to the natural phenomenon that positive and negative charges attract each other, a conductive core wire 4 with conductive properties is inserted into the conductive outer armor 1. The conductive outer armor 1 is connected to the positive pole of the control cabinet, and the conductive core wire 4 is connected to the negative pole of the supply control cabinet. Since positive and negative charges attract each other, the positive charge at the positive end is concentrated on the inner edge of the conductive outer armor 1, and the negative electrons at the negative end are concentrated on the outer edge of the conductive core wire 4. With this design, there are no electrons on the surface of the conductive outer armor 1 that contacts the oil, and there is no voltage, so there is no risk of ignition when directly heating the oil, and it has strong reliability and safety. Of course, the conductive outer armor 1 can also be connected to the negative pole of the control cabinet, and the conductive core wire 4 is connected to the positive pole of the supply control cabinet. There is no specific limitation in this embodiment.

[0037] Please refer to Figure 2 As shown, in some embodiments, a control cabinet is also provided, which includes the above-mentioned metal armored safety heating cable. The control cabinet 5 uses external industrial AC power or solar photovoltaic panels and energy storage devices as power sources. In this embodiment, the control cabinet 5 is used as the output power supply of the heating cable. The output power supply of the control cabinet 5 is configured with an isolation transformer and a constant current output controller with interchangeable positions. The conductive outer armor 1 and the conductive core wire 4 are respectively connected to the isolation transformer or the constant current output controller through wires. After the ordinary AC power output by the control cabinet 5 is electromagnetically isolated by the isolation transformer, the positive and negative poles of the output voltage are both zero to the ground, and there is only a voltage difference between the positive and negative poles. The control cabinet 5 is equivalent to turning ordinary AC power into a dry battery that can output AC power. The control cabinet structure using an isolation transformer and a constant current output controller can ensure that the heating cable does not leak electricity to the outside when it is damaged, while ensuring the safety of use.

[0038] In this embodiment, it should also be noted that when the heating cable suffers 1 to 100% damage, the heating cable and the control cabinet will have different operating states, which are explained below respectively.

[0039] Reference Figure 3 As shown, when the conductive outer armor 1, the high temperature resistant insulating layer 2, the oil resistant insulating layer 3 and the conductive core wire 4 are intact and undamaged and are in a conductive flammable and explosive liquid or a mixture of gas, liquid and solid particles, Figure 3 The path in the diagram indicates the path through which the current flows.

[0040] In order to facilitate the description of the situation in which the heating cable is damaged by 1 to 100%, in this embodiment, the conductive outer armor 1, the high temperature resistant insulation layer 2, the oil resistant insulation layer 3 and the conductive core wire 4 are regarded as having the same proportion, and the cross-sectional area of ​​the heating cable is set to the first threshold. The current path of the heating cable when it is damaged from 0 to 100% is as follows:

[0041] Reference Figure 4 As shown, when the damaged area of ​​the heating cable reaches 0-25% of the first threshold value, it is in the first state. At this time, the control cabinet is a normal cabinet when the heating cable is in the first state.

[0042] When the damaged area of ​​the heating cable reaches 0-25% of the first threshold, the conductive outer armor 1 is damaged but not completely disconnected, and the insulation layer between the conductive outer armor 1 and the conductive core wire 4 has good insulation. At this time, the conductive cross-sectional area of ​​the damaged conductive outer armor 1 becomes smaller. Since the heating cable is immersed in the conductive liquid, the current will flow through the path with the least resistance, that is, the current that the conductive outer armor 1 cannot carry will be conducted through the surrounding conductive liquid. In this case, there will be no leakage to the ground, and it will not cause local high heat or electric sparks. Figure 4 As shown, the black part indicates that the damaged part is immersed in the conductive material, and the red part in the black part indicates the path through which the current flows from the conductive material. At this time, the current value is detected to be constant, and the unit cable heating power is constant, that is, when the damaged area of ​​the heating cable reaches 0-25% of the first threshold, it is in the first state of constant current value and constant unit cable heating power, and at this time the output voltage of the control cabinet is normal, that is, it is a normal cabinet when the heating cable is in the first state.

[0043] Reference Figure 5 As shown, the heating cable is in the second state when the damaged area reaches 25% of the first threshold; the control cabinet is an abnormal cabinet when the heating cable is in the second state.

[0044] When the damaged area of ​​the heating cable reaches the limit state of 25% of the first threshold, the conductive outer armor 1 is completely damaged and disconnected, and the insulation of the insulating layer between the conductive outer armor 1 and the conductive core 4 is good. At this time, the conductive cross-sectional area of ​​the damaged conductive outer armor 1 becomes smaller. Since the heating cable is immersed in the conductive liquid, the current will flow through the path with the least resistance, that is, the current will be conducted through the conductive liquid between the cracks of the conductive outer armor 1. In this case, there will be no leakage to the ground, and it will not cause local high heat or electric sparks. Figure 5 As shown, the red part within the black part represents the path through which the current flows from the conductive material. At this time, the current detection finds that the current value is constant and the unit cable heating power is constant, that is, the damaged area of ​​the heating cable reaches the limit state of the first threshold value. 25% is in the second state in which the current value is constant and the unit cable heating power is constant; because the current is conducted in the conductive liquid and is not bound by the conductive outer armor 1, the resistance at the disconnected position becomes smaller at this time. Due to the constant current output, the output voltage of the control cabinet becomes smaller, and the control cabinet prompts an abnormality, that is, the control cabinet is an abnormal cabinet when the heating cable is in the second state.

[0045] Reference Figure 6 As shown, the heating cable is in the third state when the damaged area reaches 0-75% of the first threshold; the control cabinet is an abnormal cabinet when the heating cable is in the third state.

[0046] When the damaged area of ​​the heating cable reaches 0-75% of the first threshold, the conductive outer armor 1 is damaged but not completely disconnected, the insulation layer between the conductive outer armor 1 and the conductive core wire 4 is damaged, and the damaged area of ​​the insulation layer is very small. The current will flow through the path with the smallest resistance. At this time, the current of the conductive outer armor 1 and the conductive core wire 4 will not flow completely through the conductive liquid. In this case, there will be no leakage to the ground, and it will not cause local high heat or electric sparks. In this case, the output current of the control cabinet minus the short-circuit current at the damaged part will flow from the damaged part to the tail end, and the heating power of the heating cable will be reduced. Figure 6 As shown, the black part indicates that the damaged part is immersed in the conductive material, and the red part in the black part indicates the path through which the current flows from the conductive material. Since the damaged area of ​​the insulation layer is very small, the current flow paths at this time include paths ① and ②. The current between the damaged part and the short-circuited part at the tail end will decrease, and the heating power after the reduction will decrease in the same proportion. Whether it will drop to zero depends on whether there is current flowing through the current path ② at the damaged part. It can be understood that when the damaged area of ​​the heating cable reaches 0-75% of the first threshold, the current value from the control cabinet to the damaged part is constant, and the heating power per unit cable is constant, that is, when the damaged area of ​​the heating cable reaches 0-75% of the first threshold, it is in the third state of constant current value and constant heating power per unit cable; at this time, the output voltage of the control cabinet becomes smaller, and the control cabinet prompts an abnormality, that is, the control cabinet is an abnormal cabinet when the heating cable is in the third state.

[0047] Reference Figure 7 As shown, the heating cable is in the fourth state when the damaged area reaches 75% of the first threshold; the control cabinet is an abnormal cabinet when the heating cable is in the fourth state.

[0048] When the damaged area of ​​the heating cable reaches 75% of the first threshold limit state, the conductive outer armor 1 is completely damaged and disconnected, and the insulating layer between the conductive outer armor 1 and the conductive core wire 4 is completely damaged and disconnected. At this time, the damaged area of ​​the insulating layer is large enough, and the current will flow through the path with the smallest resistance, that is, the current of the conductive outer armor 1 and the conductive core wire 4 is completely connected through the conductive liquid. In this case, there will be no leakage to the ground, and it will not cause local high heat or electric sparks. In this case, no current will flow between the damaged part and the tail end, and the heating cable will no longer heat up. Figure 7 As shown, the black part indicates that the damaged part is immersed in the conductive material, and the red part in the black part indicates the path of the current flowing through the conductive material. The current between the damaged part and the short-circuited part at the tail end will be reduced to zero, and the heating power will be zero after the current is reduced to zero. At this time, the current value from the control cabinet to the damaged part is constant, and the heating power per unit length is constant, that is, the damaged area of ​​the heating cable reaches the limit state of the first threshold. In 75% of the cases, it is in the fourth state of constant current value and constant heating power per unit length; at this time, the output voltage of the control cabinet becomes smaller, and the control cabinet prompts an abnormality. The control cabinet is an abnormal cabinet when the heating cable is in the fourth state.

[0049] Reference Figure 8 As shown, the heating cable is in the fifth state when the damaged area reaches 75-100% of the first threshold; the control cabinet is an abnormal cabinet when the heating cable is in the fifth state.

[0050] When the damaged area of ​​the heating cable reaches 75-100% of the first threshold, the conductive outer armor 1 is damaged and completely disconnected, the insulating layer between the conductive outer armor 1 and the conductive core wire 4 is completely damaged, and the conductive core wire 4 is damaged; at this time, the current will flow through the path with the least resistance. At this time, the current of the conductive outer armor 1 and the conductive core wire 4 is completely connected through the conductive liquid. In this case, there will be no leakage to the ground, and it will not cause local high heat or electric sparks. At the same time, in this case, no current will flow between the damaged part and the tail end, and the heating cable will no longer heat up. Figure 8As shown, the black part indicates that the damaged part is immersed in the conductive material, and the red part in the black part indicates the path of the current flowing from the conductive material. The current between the damaged part and the short-circuited part at the tail end will be reduced, and the heating power after the reduction will be reduced in the same proportion. Whether it will drop to zero depends on whether there is current flowing through the current path ② at the damaged part. When the damage is near the tail end, the resistance value between the damaged part and the tail end is very small, so some current may also flow through the current path ②. At this time, the current value from the control cabinet to the damaged part is constant, and the heating power per unit length is constant, that is, when the damaged area of ​​the heating cable reaches 75-100% of the first threshold, it is in the fifth state of constant current value and constant heating power per unit length; at this time, the output voltage of the control cabinet becomes smaller, and the control cabinet is abnormal. The control cabinet is an abnormal cabinet when the heating cable is in the fifth state.

[0051] Reference Fig. 9 As shown, when the damaged area of ​​the heating cable reaches 100% of the first threshold value, it is in the sixth state; the control cabinet is an abnormal cabinet when the heating cable is in the sixth state.

[0052] When the damaged area of ​​the heating cable reaches the limit state of 100% of the first threshold, the conductive outer armor 1 is damaged and completely disconnected, the insulating layer between the conductive outer armor 1 and the conductive core wire 4 is completely damaged, and the conductive core wire 4 is completely damaged; Fig. 9 As shown, the black part indicates that the damaged part is immersed in the conductive material, and the red part in the black part indicates the path of the current flowing through the conductive material. The current between the damaged part and the short-circuited part at the tail end will be reduced to zero. After the current is reduced to zero, the heating power will be zero, and the heating cable will no longer generate heat. At this time, the current value from the control cabinet to the damaged part is constant, and the heating power per unit length is constant, that is, when the damaged area of ​​the heating cable reaches 100% of the first threshold, it is in the sixth state of constant current value and constant heating power per unit length; the output voltage of the control cabinet becomes smaller, the control cabinet is abnormal, and the control cabinet is an abnormal cabinet when the heating cable is in the sixth state.

[0053] Implementation principle of this embodiment: In this embodiment, a control cabinet structure of an isolation transformer and a constant current output controller is adopted. After ordinary AC power is electromagnetically isolated by the isolation transformer, the voltage of the positive and negative poles of the output voltage to the ground is zero, and there is only a voltage difference between the positive and negative poles. The control cabinet is equivalent to turning ordinary AC power into a dry battery that can output AC power, and the heating cable will not experience a surge in output power or high-temperature breakage of the heating wire after being damaged to different degrees. By adopting constant current output, the control cabinet will not have the hidden danger of a surge in output current and thus a surge in output power caused by a decrease in resistance when the heating cable suffers any damage.

[0054] The following example illustrates the safety brought by the constant current output of the control cabinet in this application in the special field of oil transportation;

[0055] by Figure 7 Take this as an example, L represents the total length, L1 represents the length with current, L2 represents the length without current, and W represents the power of a single meter of heating cable. At this time:

[0056]

[0057]

[0058]

[0059] From the above, it can be concluded that when the control cabinet adopts constant voltage output, that is, the voltage is constant, if the heating cable is damaged: the heating power of a single meter heating cable increases When the current value exceeds the load limit of the heating cable, the cable power will be overloaded in a very short time, and there are hidden dangers of fire and explosion caused by high heat. The closer the damaged point is to the control cabinet, the greater the risk of hidden dangers. If the heating cable breaks in the middle, the heating power per meter will increase by 4 times, far exceeding the load limit of the cable.

[0060] In this embodiment, the control cabinet adopts a constant current output mode, that is, when the current is constant:

[0061]

[0062]

[0063]

[0064] From the above, it can be concluded that since the current is constant, no matter where the heating cable is damaged, it will not cause changes in the power per meter, completely eliminating the hidden risks of previous equipment.

[0065] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0066] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A metal armored safety heating cable, characterized in that: Used in a petroleum oil and gas pipeline, the metal armored safety heating cable comprises: a conductive outer armor (1) and a conductive core wire (4); an insulating layer is arranged between the conductive outer armor (1) and the conductive core wire (4), and the insulating layer is arranged to be made of a single layer or multiple layers of oil-resistant and high-temperature resistant material; Wherein, the insulating layer comprises an oil-resistant insulating layer (3) and a high-temperature-resistant insulating layer (2); The oil-resistant insulating layer (3) comprises oil-resistant nitrile or oil-resistant silicone; The high temperature resistant insulating layer (2) comprises a mica braided layer.

2. The metal armored safety heating cable according to claim 1, characterized in that: The conductive outer armor (1), the high temperature resistant insulating layer (2), the oil resistant insulating layer (3) and the conductive core wire (4) constitute a heating cable; One end of the conductive outer armor (1) and the conductive core wire (4) are respectively connected to the positive and negative poles of the control cabinet, and the other ends of the conductive outer armor (1) and the conductive core wire (4) are short-circuited with each other via a wire.

3. A control cabinet, characterized in that: It comprises the metal armored safety heating cable as described in claim 2, and the control cabinet (5) adopts external industrial alternating current or solar photovoltaic panels and energy storage devices as power supply sources.

4. The control cabinet according to claim 3, characterized in that: The output power supply of the control cabinet (5) is configured with an isolation transformer and a constant current output controller whose positions are interchangeable; The conductive outer armor (1) and the conductive core wire (4) are respectively connected to the isolation transformer or the constant current output controller via conductive wires.

5. The control cabinet according to claim 4, characterized in that: The cross-sectional area of ​​the heating cable is set to a first threshold; The heating cable is in a first state when the damaged area reaches 0-25% of the first threshold value; the control cabinet (5) is a normal cabinet when the heating cable is in the first state.

6. The control cabinet according to claim 5, characterized in that: When the damaged area of ​​the heating cable reaches 25% of the first threshold value, the heating cable is in the second state; and the control cabinet (5) is an abnormal cabinet when the heating cable is in the second state.

7. The control cabinet according to claim 4, characterized in that: The cross-sectional area of ​​the heating cable is set to a first threshold; When the damaged area of ​​the heating cable reaches 0-75% of the first threshold value, the heating cable is in the third state; and the control cabinet (5) is an abnormal cabinet when the heating cable is in the third state.

8. The control cabinet according to claim 7, characterized in that: When the damaged area of ​​the heating cable reaches 75% of the first threshold value, the heating cable is in the fourth state; and the control cabinet (5) is an abnormal cabinet when the heating cable is in the fourth state.

9. The control cabinet according to claim 4, characterized in that: The cross-sectional area of ​​the heating cable is set to a first threshold; When the damaged area of ​​the heating cable reaches 75%-100% of the first threshold value, the heating cable is in the fifth state; and the control cabinet (5) is an abnormal cabinet when the heating cable is in the fifth state.

10. The control cabinet according to claim 9, characterized in that: When the damaged area of ​​the heating cable reaches 100% of the first threshold value, the heating cable is in the sixth state; and the control cabinet (5) is an abnormal cabinet when the heating cable is in the sixth state.

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