A natural gas pipeline heat tracing device

Abstract

The utility model provides a natural gas pipeline heat tracing heat preservation device, including protection shell and pipeline main part, the protection shell is wrapped in the outside of pipeline main part. The utility model solves the problem that current electric heat tracing energy consumption is high, temperature can't be automatically regulated, and steam heat tracing system is complex, temperature is difficult accurate control. Through winding graphene heating film outside pipeline main part, and installing temperature sensor between both, temperature sensor can real -time monitoring pipeline main part surface temperature, after collocation suitable controller, can automatically regulate graphene heating film's heating power according to monitoring temperature - when environment temperature is too low, pipeline temperature is lower than setting, controller drives heating film to promote power to make up heat, when environment temperature rises, pipeline temperature reaches setting, controller reduces heating film power or closes, avoids condensate accumulation, frozen risk caused by too low temperature, prevents energy waste caused by too high temperature, realizes the dual effect of accurate temperature control and energy saving.

Description

Technical Field

[0001] This utility model relates to the field of pipeline heat tracing and insulation technology, and in particular to a natural gas pipeline heat tracing and insulation device. Background Technology

[0002] When natural gas pipelines operate in low-temperature environments during winter, the natural gas inside is prone to condensation and accumulation due to the excessively low temperature, leading to a decrease in pipeline transportation efficiency and, in severe cases, even causing pipeline freezing, blockage, rupture, and other safety accidents. Existing pipeline heat tracing and insulation technologies are mainly divided into two categories: electric heat tracing and steam heat tracing. Electric heat tracing technology: It uses constant power electric heat tracing tape to wind the pipe, which has the problems of high energy consumption and inability to automatically adjust the temperature according to the environment. When the ambient temperature rises, it is easy to waste energy, and when the temperature is too low, it is difficult to meet the heat preservation requirements. Steam tracing technology: This technology transfers heat to natural gas pipelines via steam pipelines. It requires the construction of a steam generator, making the system complex and costly. Furthermore, the steam temperature is difficult to control precisely, and localized overheating can easily damage the pipeline's anti-corrosion layer. In addition, existing insulation structures mostly use a single insulation material, resulting in poor adhesion between the insulation layer and the pipe, leading to rapid heat loss and unstable insulation performance.

[0003] Therefore, it is necessary to provide a natural gas pipeline heat tracing and insulation device to solve the above-mentioned technical problems. Utility Model Content

[0004] This utility model provides a heat tracing and insulation device for natural gas pipelines, which solves the problems in the background art. To address the aforementioned technical problems, this utility model provides a natural gas pipeline heat tracing and insulation device. The device uses the pipeline body for transporting natural gas as its core carrier. The pipeline body is arranged horizontally or at an angle, and its outer surface is tightly wrapped with a graphene heating film, forming a ring-shaped wrapping structure that can be fixed without additional fasteners. A temperature sensor is fixed in the gap between the pipeline body and the graphene heating film by adhesive or clips, maintaining close contact with both the outer surface of the pipeline body and the inner surface of the graphene heating film, enabling real-time acquisition of the pipeline body's temperature data. A protective outer shell is fitted over the graphene heating film, completely enclosing the pipeline body, the graphene heating film, and the temperature sensor. Simultaneously, a controller adapted to the graphene heating film is connected to the temperature sensor and the graphene heating film via wires, forming an electrical signal transmission link. During operation, the temperature sensor transmits the collected temperature data to the controller. The controller compares the data with the preset safe temperature range and sends an electrical signal to the graphene heating film to adjust the heating power. When the temperature is too low, the heating film is driven to heat up, and the heat is conducted to the main body of the pipe to prevent condensation. When the temperature is too high, the power is reduced or the power is cut off to avoid waste and damage. The protective shell isolates the internal parts from low temperature, rain and impact, and protects them to ensure stable operation.

[0005] Preferably, the outer surface of the graphene heating film is covered with a modified polyurethane foam layer. This foam layer, with its own flexibility and adhesion (or auxiliary adhesive), tightly wraps the heating film without obvious gaps. A glass wool felt layer is then fixed to the outside of the modified polyurethane foam layer by wrapping or bonding. Both insulation materials are tightly fitted to the inner components without loosening, forming a multi-layered nested structure from the inside out: "pipe body → temperature sensor → graphene heating film → modified polyurethane foam layer → glass wool felt layer → protective shell". When the graphene heating film generates heat, the heat is preferentially conducted to the pipe body. Some of the heat diffusing outward is absorbed and locked by the tightly fitted modified polyurethane foam layer, reducing heat loss due to gaps between layers. Its flexibility also ensures a good fit and prevents localized leakage. The outer glass wool felt layer, with its porous structure, further blocks heat diffusion to the outside, forming a dual insulation effect of "inner layer heat locking + outer layer heat insulation," improving heat utilization efficiency and maintaining stable pipe temperature, avoiding the influence of low external temperatures.

[0006] Preferably, the protective shell consists of two symmetrical arc-shaped protective plates, the curvature of which matches the outer curvature of the glass wool felt layer. The two arc-shaped protective plates are fastened together from the top and bottom (or left and right) sides of the pipe body. Each arc-shaped protective plate has a closing plate (integrated with or welded to the protective plate) fixed at both ends. The closing plate has through fixing holes on its surface. After the two protective plates are fastened together, the closing plates at both ends fit together, and fasteners (such as bolts and nuts) pass through the corresponding fixing holes to lock them together, forming a complete cylindrical protective shell. The arc design ensures that the protective plate fits tightly with the glass wool felt layer, avoiding gaps that could lead to heat loss. The cooperation between the closing plate and the fasteners allows the shell to be disassembled, facilitating later maintenance of the internal insulation and heating components. At the same time, the overall closed structure can prevent rainwater and dust from entering, preventing the temperature sensor and graphene heating film from becoming damp or contaminated and malfunctioning.

[0007] Preferably, the protective shell has multiple fasteners, the number of which is determined according to the pipe diameter (usually one every 10-20cm), and they are evenly distributed on the closing plate along the axial direction of the protective shell (the direction of pipe transport). Each fastener passes through two fixing holes that fit the closing plate. The even distribution ensures that the protective shell is subjected to uniform force when closed, avoiding insufficient local fastening force that could cause the shell to loosen, thereby preventing the internal insulation layer from shifting. At the same time, the uniform fastening force can maintain a tight fit between the protective shell and the glass wool felt layer, reducing interlayer gaps and helping to improve the overall insulation effect.

[0008] Preferably, the protective outer shell is made of polyethylene, which completely covers the outside of the glass wool felt layer. This material has the characteristics of low temperature resistance, impact resistance, and corrosion resistance. In low-temperature environments in winter, polyethylene will not become brittle and crack due to low temperatures, thus providing stable protection for the internal heating and insulation components; its impact resistance can withstand damage to the internal system from external collisions such as accidental contact with construction equipment and impacts from wind and snow; and its corrosion resistance can prevent rainwater and corrosive substances in the soil from corroding the outer shell, extending the overall service life of the device and ensuring long-term stable operation.

[0009] Preferably, the graphene heating film is equipped with a corresponding controller. The controller is typically installed in a distribution box near the pipeline (or mounted on the outside of a protective casing for easy operation), and is connected to the graphene heating film and the temperature sensor via wires. As the system's "core control unit," the controller receives real-time temperature data from the temperature sensor and sends precise electrical signals to the graphene heating film according to a preset program, achieving automatic adjustment of heating power. Simultaneously, the controller can store temperature data and record the heating film's operating status. When abnormal temperatures occur (such as exceeding the safe range) or component malfunctions (such as no data feedback from the sensor), it can promptly issue alarm signals, ensuring the intelligent and safe operation of the heat tracing and insulation system.

[0010] Compared with related technologies, the natural gas pipeline heat tracing and insulation device provided by this utility model has the following beneficial effects: Compared to existing technologies, this method solves the problems of high energy consumption and lack of automatic temperature adjustment in electric heat tracing systems, as well as the complexity and difficulty in precise temperature control in steam heat tracing systems. By wrapping a graphene heating film around the outside of the pipe body and installing a temperature sensor between them, the temperature sensor can monitor the surface temperature of the pipe body in real time. With a suitable controller, it can automatically adjust the heating power of the graphene heating film according to the monitored temperature. When the ambient temperature is too low and the pipe temperature is below the set value, the controller drives the heating film to increase its power to supplement heat; when the ambient temperature rises and the pipe temperature reaches the set value, the controller reduces the power of the heating film or shuts it off. This avoids the risk of condensation and freezing due to excessively low temperatures, and also prevents energy waste caused by excessively high temperatures, achieving the dual effect of precise temperature control and energy saving.

[0011] Compared with existing technologies, this invention improves upon the shortcomings of existing single insulation materials, such as poor adhesion, rapid heat loss, and unstable insulation performance. The modified polyurethane foam layer wrapped around the graphene heating film has excellent flexibility and adhesion, tightly wrapping the heating film and the main pipe body, reducing heat loss caused by gaps between layers. The outer glass wool felt layer has excellent high-temperature resistance and thermal insulation properties, further preventing the heat generated by the heating film from diffusing to the outside. This forms a dual insulation structure of "tightly bonded modified polyurethane foam layer for heat locking + highly efficient glass wool felt layer for heat insulation," significantly reducing the rate of heat loss, improving the stability of the insulation effect, and avoiding the problem of localized insulation failure caused by poor adhesion when using single materials.

[0012] The parts of the device not covered herein are the same as or can be implemented using existing technologies. Attached Figure Description

[0013] Figure 1 A schematic diagram of the structure of a natural gas pipeline heat tracing and insulation device provided by this utility model; Figure 2 A cross-sectional view of a natural gas pipeline heat tracing and insulation device provided by this utility model; Figure 3 A schematic diagram of the graphene heating film structure of a natural gas pipeline heat tracing and insulation device provided by this utility model; Figure 4 A schematic diagram of the arc-shaped protective plate structure of a natural gas pipeline heat tracing and insulation device provided by this utility model.

[0014] Numbering on the map: 1. Protective outer shell; 2. Pipe body; 3. Closure plate; 4. Fasteners; 5. Controller; 6. Glass wool felt layer; 7. Modified polyurethane foam layer; 8. Graphene heating film; 9. Temperature sensor; 10. Arc-shaped protective plate; 11. Fixing holes. Detailed Implementation

[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0016] Example 1 Please refer to the following: Figure 1-4A natural gas pipeline heat tracing and insulation device is described. The device centers on a cylindrical metal pipeline body 2 (made of materials such as carbon steel or stainless steel, suitable for the pressure resistance requirements of natural gas transportation). Before installation, the outer surface of the pipeline must be cleaned of oil and rust to ensure flatness. A rolled graphene heating film 8 (width matched to the pipeline diameter, e.g., a 50mm wide heating film is suitable for a 100mm diameter pipeline) is spirally wound onto the outer surface of the pipeline, with a winding spacing of 5-10mm (adjustable according to insulation requirements). It is fixed with self-adhesive or high-temperature resistant adhesive to ensure 100% adhesion to the outer surface of the pipeline without gaps. A patch-type PT1000 temperature sensor 9 (low-temperature resistant, high-precision) is preferably installed in the lower half of the horizontal section of the pipeline (area where low-temperature condensable liquids accumulate). Before installation, thermally conductive silicone grease is applied to the corresponding position on the pipeline to improve heat conduction efficiency, then the sensor is pasted and fixed, and finally the graphene heating film 8 is covered, so that the inner surface of the heating film tightly presses against the sensor, forming a "pipeline body 2 - thermally conductive silicone grease - sensor - The graphene heating film 8” features a tight contact structure to prevent poor contact from causing temperature monitoring delays. Before installation, the polyethylene protective shell 1 (prefabricated arc structure) requires the internal components to be assembled. Two arc-shaped protective plates 10 (the arc matching the outer diameter of the pipe body 2 plus the thickness of the heating film) are fastened from the top and bottom sides of the pipe, aligning with the pipe axis. A 2-3mm gap is left between the inner side and the outer side of the graphene heating film 8 (to allow space for thermal expansion and prevent damage from compression). The industrial-grade controller 5 (operating temperature range -40℃ to 85℃) with temperature display and automatic adjustment functions is installed in a distribution box 1-2m away from the pipe. It is connected to the temperature sensor 9 via a low-temperature resistant wire (passed through a metal corrugated pipe for interference prevention) and to the power supply terminal of the graphene heating film 8 via a wire. The wiring distinguishes between positive and negative terminals to ensure signal stability. During operation, temperature sensor 9 transmits temperature data to controller 5 every second with an accuracy of ±0.5℃. Controller 5 is preset to a temperature range of 5℃~15℃ (based on the freezing point of natural gas). When the temperature is <5℃, it outputs 220V AC power, causing the heating film to heat up at a power of 20-30W / m. The heat is quickly conducted to the main body of the pipe 2 through the tight contact surface to achieve temperature rise. When the temperature is >15℃, the power is cut off and heating stops. The protective shell 1 maintains structural stability due to its low-temperature resistance with an embrittlement temperature below -70℃, preventing wind, snow, and dust from contacting the internal components and avoiding short circuits caused by moisture in the heating film and damage to the sensor. Ultimately, through the combination of "tightly wrapped heating film + accurate temperature measurement by sensor + automatic temperature control by controller 5", the problems of high energy consumption of existing electric heat tracing and difficult temperature control of steam heat tracing are solved, achieving the technical effects of accurate temperature control, energy saving, and prevention of condensate freezing and blockage.

[0017] Example 2 Please refer to the following: Figure 1-4The modified polyurethane foam layer 7 is a prefabricated tubular shape with an inner diameter consistent with the outer diameter of the pipe after the graphene heating film 8 is wrapped. During installation, it is cut along the axial direction to wrap the outer side of the heating film. The overlap is bonded with polyurethane special adhesive with a width of ≥10mm to ensure a tight fit without gaps. At the same time, the joints of the foam layer are staggered with the joints of the heating film (to avoid double joints and heat leakage). Each section of the foam layer is 2-3m long, and the sections are bonded with the same overlap to form a continuous insulation layer. The width of the centrifugal glass wool felt layer 6 matches the length of the foam layer. It is wrapped around the outside of the foam layer along the axial direction of the pipe. When wrapping, it is kept flat and wrinkle-free. The overlap width of each circle is ≥50mm. The overlap is bonded and fixed with high-temperature resistant aluminum foil tape (which has both sealing and heat reflection functions). The outside of the felt layer is then wrapped with a layer of glass fiber cloth in a spiral winding manner to enhance the structural strength and prevent it from falling off. During operation, over 90% of the heat from the graphene heating film 8 is conducted to the main pipe body 2. A small amount of heat diffusing outward is trapped by the closed-cell structure of the modified polyurethane foam layer 7, reducing convective heat transfer and preventing heat penetration. The remaining trace heat is further blocked by the porous structure of the glass wool felt layer 6 with a porosity ≥90%, weakening heat radiation and heat conduction. The aluminum foil tape can also reflect some heat back to the foam layer, forming a triple insulation effect of "foam layer heat locking + glass wool felt layer 6 heat insulation + aluminum foil reflection". This structure, through the combination of "tightly bonded modified polyurethane foam layer 7 + multi-layered wrapping of glass wool felt layer 6", solves the defects of poor adhesion and rapid heat dissipation of existing single insulation materials. The composite thermal conductivity of the double insulation layer is ≤0.020W / (m•K), reducing the heat loss rate of the pipe by more than 60%, improving the stability of the insulation effect by 50%, avoiding local insulation failure, and ensuring that the pipe temperature remains stable within the preset range.

[0018] Example 3 Please refer to the following: Figure 1-4The arc-shaped protective plate 10 is a polyethylene extrusion molded part. The rectangular closed plate 3 of the same material is fixed to both ends of the protective plate by hot melt welding. The weld depth is ≥3mm to prevent cracking. M8 threaded holes are pre-drilled on the surface of the closed plate 3. The positional error of the closed plate 3 of the two arc-shaped protective plates 10 is ≤0.5mm to ensure that the fastener 4 can pass smoothly after fastening. During installation, first place the lower arc-shaped protective plate 10 on the pipe support, and then fasten the upper protective plate from above. Adjust the position so that the gap between the two closed plates 3 is ≤0.2mm. Then, use M8×30mm stainless steel bolts (corrosion resistant) to pass through the fixing holes 11, and use spring washers and flat washers to tighten with a torque wrench to a torque of 15N•m to ensure that the protective plate is tightly fixed without loosening. During operation, the arc of the curved protective plate 10 perfectly matches the outer diameter of the glass wool felt layer 6. After fastening, the gap between the inner side and the outer side of the felt layer is ≤1mm. This not only restricts the displacement of the felt layer but also absorbs external forces such as collisions with construction equipment and impacts from stones due to structural strength, preventing damage to the internal insulation layer. The closing plate 3 and the fasteners 4 work together to form a sealed structure, preventing rainwater and dust from entering the interior and preventing the modified polyurethane foam layer 7 from absorbing moisture (moisture absorption will increase the thermal conductivity and reduce the insulation effect) and the graphene heating film 8 from short-circuiting. This design solves the problems of poor sealing and easy damage to the internal insulation layer of existing protective structures through the combination of "arc-shaped fitting + closed sealing + fastening". The low-temperature resistance and impact resistance of the polyethylene protective plate, combined with the sealed structure, ensures stable operation of the device in low-temperature environments such as winter snow. The detachable fastening method facilitates later maintenance (it can be opened by loosening the bolts without damaging the internal structure).

[0019] Example 4 Please refer to the following: Figure 1-4 Multiple fasteners 4 are installed on the protective shell 1, the number of which is determined according to the pipe diameter. They are evenly distributed on the closing plate 3 along the axial direction of the protective shell 1 (pipe transport direction), and each fastener 4 passes through two fixing holes 11 that fit the closing plate 3. The even distribution ensures that the protective shell 1 is subjected to uniform force when closed, avoiding insufficient local fastening force that could cause the shell to loosen, thereby preventing the internal insulation layer from shifting. At the same time, the uniform fastening force can maintain a tight fit between the protective shell 1 and the glass wool felt layer 6, reducing interlayer gaps and helping to improve the overall insulation effect.

[0020] Example 5 Please refer to the following: Figure 1-4 The protective outer shell 1 is made of polyethylene and completely covers the outside of the glass wool felt layer 6. This material has the characteristics of low temperature resistance, impact resistance, and corrosion resistance. In low-temperature environments in winter, polyethylene will not become brittle and crack due to low temperatures, and can stably protect the internal heating and insulation parts; its impact resistance can resist damage to the internal system from external collisions such as accidental contact with construction equipment and impacts from wind and snow; its corrosion resistance can prevent rainwater and corrosive substances in the soil from corroding the outer shell, extending the overall service life of the device and ensuring long-term stable operation.

[0021] Example 6 Please refer to the following: Figure 1-4 The graphene heating film 8 is equipped with a corresponding controller 5. The controller 5 is usually installed in a distribution box near the pipeline (or mounted on the outside of the protective shell 1 for easy operation), and is connected to the graphene heating film 8 and the temperature sensor 9 via wires. As the "core control unit" of the system, the controller 5 receives real-time temperature data transmitted by the temperature sensor 9 and sends precise electrical signals to the graphene heating film 8 according to a preset program to achieve automatic adjustment of heating power. At the same time, the controller 5 can store temperature data and record the working status of the heating film. When abnormal temperature occurs (such as exceeding the safe range) or component failure occurs (such as no data feedback from the sensor), it can promptly issue an alarm signal to ensure the intelligent and safe operation of the heat tracing and insulation system.

[0022] It should be noted that the control circuit of controller 5 can be implemented by those skilled in the art through simple programming, and is common knowledge in the field. It is only used and not modified, so the control method and circuit connection will not be described in detail.

[0023] The working principle of the natural gas pipeline heat tracing and insulation device provided by this utility model is as follows: The working principle of this natural gas pipeline heat tracing and insulation device revolves around a coherent process of "temperature monitoring - intelligent heat control - double insulation - anomaly response." Specifically, after installation, the entire insulation system is encased in a protective shell 1 (made of low-temperature resistant and impact-resistant polyethylene material, protecting the internal structure from external damage) secured by two arc-shaped polyethylene protective plates and equidistant fasteners 4. When the pipeline body 2 is normally transporting natural gas, the temperature sensor 9 located between the pipeline body 2 and the graphene heating film 8 is activated first, collecting real-time temperature data of the outer surface of the pipeline body 2 and continuously transmitting it to the matching controller 5, forming a real-time temperature feedback link. The controller 5 has a preset safe temperature range set according to the requirements of the natural gas transportation process (the lower limit is the temperature to avoid condensation accumulation, and the upper limit is the temperature to prevent damage to the pipeline anti-corrosion layer). After receiving the temperature data, it compares and analyzes it with the preset range. If the monitored temperature is below the lower limit, the controller 5 drives the graphene heating film 8 to generate heat, utilizing its high thermal conductivity and uniform heating characteristics to quickly replenish the heat of the pipeline body 2, preventing the accumulation of natural gas condensate inside the pipe. If the temperature is within the range, the controller 5 maintains the heating film at low power to offset normal heat loss and ensure temperature stability. If the temperature is above the upper limit, the controller 5 reduces the power of the heating film or cuts off the power to avoid energy waste and damage to the anti-corrosion layer. At the same time, the modified polyurethane foam layer 7 on the outside of the graphene heating film 8 tightly wraps the heating film with its good flexibility and fit, filling tiny gaps to achieve "close-range heat locking". The outer glass wool felt layer 6 is porous. The structure blocks heat from spreading to the outside, forming a double insulation structure. This reduces heat loss from the heating film, extends the insulation time, and also blocks the impact of low external temperatures on the pipeline. In addition, if the temperature sensor 9 malfunctions or the heating film power is abnormal, the controller 5 will issue an alarm signal to remind maintenance through a preset fault detection program (such as identifying that the temperature data has not changed for a long time or that the power and temperature changes are mismatched). The arc-shaped structure and tight fit design of the protective shell 1 can also prevent rainwater and impurities from entering, helping to maintain a stable internal insulation environment. Ultimately, this ensures that the device can operate reliably for a long time in low-temperature winter environments, avoiding safety accidents such as condensate accumulation, freezing blockage, and rupture in the pipeline.

[0024] It should be noted that all components used in this application are standard parts that can be purchased from the market. The specific connection methods of each part adopt conventional methods such as bolts, rivets and welding that are mature in the prior art. The mechanical parts and electrical equipment adopt conventional models in the prior art. The circuit connection adopts conventional connection methods in the prior art. The electrical equipment is connected to an external safe power source. These will not be described in detail here.

[0025] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the description and drawings of this utility model, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A natural gas pipeline heat tracing device comprising a protective outer shell (1) and a pipeline body (2), characterized in that, The protective shell (1) is wrapped around the outside of the pipe body (2), and a graphene heating film (8) is wrapped around the outer surface of the pipe body (2). A temperature sensor (9) is installed between the pipe body (2) and the graphene heating film (8).

2. A natural gas pipeline heat tracing device according to claim 1, wherein, The graphene heating film (8) has a modified polyurethane foam layer (7) wrapped on its outer surface, and a glass wool felt layer (6) is wrapped on the outer side of the modified polyurethane foam layer (7).

3. A natural gas pipeline heat tracing device according to claim 1, wherein, The protective shell (1) is composed of two arc-shaped protective plates (10). The arc-shaped protective plates (10) are equipped with closing plates (3) at both ends. The closing plates (3) have fixing holes (11) on their surfaces. The two arc-shaped protective plates (10) are fixed by fasteners (4) through the fixing holes (11).

4. A natural gas pipeline heat tracing device according to claim 3, wherein, Multiple fasteners (4) are installed, and the multiple fasteners (4) are installed at equal intervals on the protective shell (1).

5. A natural gas pipeline heat tracing device according to claim 1, wherein, The protective shell (1) is made of polyethylene.

6. A natural gas pipeline heat tracing device according to claim 1, wherein, The graphene heating film (8) is adapted to a corresponding controller (5).

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