Insulated pipes that monitor the loss of insulation layer in real time

Abstract

This utility model discloses an insulated pipe for real-time monitoring of insulation layer wear. The pipe includes a casing with an internal insulation structure. This insulation structure comprises a wear-resistant layer and an insulation layer located between the wear-resistant layer and the casing. The insulation layer includes a nano-insulation layer and an aluminum silicate insulation layer. Both the wear-resistant layer and the insulation layer are annular structures that completely fill the inner wall of the casing. Multiple anchors are embedded within the insulation and wear-resistant layers. Temperature sensors are mounted on the surface of each anchor. The anchors extend laterally within the horizontal cross-section of the insulation and wear-resistant layers, with the axis of the casing perpendicular to this horizontal cross-section. This utility model can record the wear condition of the internal wear-resistant layer in real-time based on temperature detection, providing data support for the safe and efficient operation of hot air ducts.

Description

Technical Field

[0001] This utility model relates to the field of thermal insulation pipe technology, and in particular to thermal insulation pipes for real-time monitoring of the loss of the insulation layer inside the pipe. Background Technology

[0002] In industrial applications, high-temperature hot air ducts serve as crucial conveying equipment for high-temperature hot air, as the flue gas temperature in these ducts is relatively high. Taking high-temperature hot air ducts in pellet production as an example, high-temperature hot air is transported from the annular cooler to the chain grate section via an exhaust fan and hot air duct. The hot air temperature in the blower drying section of the duct is 180–250°C, in the exhaust drying section it is 380–500°C, in preheating section I it is 650–700°C, and in preheating section II it is 950–1100°C. Simultaneously, the exhaust fan in the annular cooler section carries particles into the flue gas duct, with dust concentrations reaching up to 800 mg / m³. Therefore, there are two key issues in the production of high-temperature hot air ducts: firstly, minimizing heat loss during hot air transport; and secondly, reducing wear on the internal protective layer of the hot air duct under the high-speed impact of the flue gas. Hot air ducts widely adopt internal insulation structures. The insulation material near the steel pipe is generally made of high-temperature resistant aluminum silicate fiber, while the material near the internal high-temperature hot air is generally made of wear-resistant spray coating.

[0003] Patent CN 202947146U proposes a thermal insulation structure for a smelting flue gas combustion pipeline, featuring a concentric four-layer structure. The outermost layer is a steel plate, the innermost layer is a hexagonal wire mesh, and between these layers, from the outside in, are a calcium silicate board layer and a mullite high-strength refractory castable layer. Patent CN202972377U proposes a thermal insulation pipe for a submerged arc furnace flue gas, with anchors evenly distributed and fixed on the inner wall of the flue gas pipeline. Coal tar paint is applied to the inner wall of the flue gas pipeline and the anchors. The insulation layer consists of an aluminum silicate layer, a wire mesh, an asbestos board, and a ceramic fiber layer sequentially arranged on the inner wall of the flue gas pipeline. Both patents propose different insulation structures for pipeline insulation, but it can be seen that the insulation materials used are both aluminum silicate, a material with a high thermal conductivity, which limits the insulation capacity of the pipeline. Furthermore, they address the issue of flue gas wear in the pipeline.

[0004] Patent CN 202992524U proposes a wear-resistant and heat-insulating structure for high-temperature flue gas ducts, including a steel pipe, a fire-resistant and wear-resistant layer, an inner heat insulation layer, reinforcing ribs, an outer heat insulation layer, galvanized iron sheet, heat-insulating fasteners, iron wire, and iron wire mesh. The axial outer surface of the fire-resistant and wear-resistant layer is connected to the axial inner surface of the inner heat insulation layer. This wear-resistant and heat-insulating structure can better reduce heat loss from high-temperature flue gas, resulting in better heat insulation, while also providing wear resistance. A review of existing patents for high-temperature hot air ducts reveals that conventional duct internal insulation widely uses insulation materials with high thermal conductivity, such as aluminum silicate. Even with wear-resistant layers, wear on the ducts is still unavoidable in actual production. The wear-resistant and insulation materials for hot air ducts require maintenance workers to inspect and repair them during maintenance periods, which is difficult and makes it impossible to monitor the insulation and wear status of the insulation layer in real time.

[0005] Nano-insulation materials, as a new type of insulation material, are characterized by the use of nanotechnology. The material has a low thermal conductivity, which is 1 / 10 of that of general insulation materials, reaching 0.02 W / (m·K). However, the disadvantage is that the heat resistance is poor and it is easy to melt and fail at high temperatures. Traditional hot air duct insulation causes great wear to the inner lining due to flue gas, and it is impossible to monitor the wear of the inner lining of the duct in a timely manner. Utility Model Content

[0006] The purpose of this invention is to address the shortcomings of existing technologies by proposing a real-time monitoring system for the wear of the insulation layer inside the pipe. This system can record the wear of the wear-resistant layer inside the pipe based on real-time temperature detection, providing data support for the safe and efficient operation of hot air ducts.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] An insulated pipe for real-time monitoring of insulation layer loss includes a pipe skin. An insulation structure is installed inside the pipe skin. The insulation structure includes a wear-resistant layer and an insulation layer located between the wear-resistant layer and the pipe skin. The insulation layer includes a nano-insulation layer and an aluminum silicate insulation layer. Both the wear-resistant layer and the insulation layer have annular structures and completely fill the inner wall of the pipe skin. Multiple anchors are embedded inside the insulation layer and the wear-resistant layer. Temperature sensors are installed on the surface of the anchors. The anchors extend to both sides within the horizontal cross-section of the insulation layer and the wear-resistant layer. The axis of the pipe skin is perpendicular to the horizontal cross-section. Multiple temperature sensors are arranged along the length of the anchors. The multiple temperature sensors are electrically connected to a central processing unit via sensor data cables on the outside of the pipe skin.

[0009] Preferably, the anchor is V-shaped and includes two cross-arranged anchor rods, with a plurality of temperature sensors extending along the length of the anchor rods.

[0010] Preferably, the anchor further includes an anchor base, which is detachably connected to the intersection of the two anchor rods, and the anchor base is located on the side closer to the tube skin.

[0011] Preferably, the plurality of temperature sensors are arranged at equal intervals along the length of the anchor.

[0012] Preferably, multiple anchors and temperature sensors are arranged equidistantly around the circumference of the pipe skin, with the number of temperature sensors being less than the number of anchors, and a number of anchors separating two adjacent temperature sensors.

[0013] Preferably, the thickness of the nano-insulation layer and the aluminum silicate insulation layer is 10-50 mm.

[0014] Compared with the prior art, the advantages of this utility model are as follows:

[0015] The use of nano-insulation materials can greatly improve the thermal insulation effect of pipelines. Furthermore, by setting anchors, the positioning of the wear-resistant layer and insulation layer can be enhanced, and the fixing and adhesion of the materials inside the pipeline can be strengthened. Multiple temperature sensors are set on the surface of the anchors, which can detect the temperature inside and outside the pipeline in real time. By detecting temperature changes, the degree of wear of the insulation layer inside the pipeline can be detected. When the wear of the insulation layer exceeds the threshold, the relevant structure can be adjusted and the machine stopped in time to avoid production safety accidents. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of this utility model.

[0017] Figure 2 This is a schematic diagram of the internal structure of the present invention in a vertical cross-section.

[0018] Figure 3 This is a schematic diagram of the internal structure of the present invention in a horizontal cross-section.

[0019] Figure 4 This is a schematic diagram of the anchor and temperature sensor structure of this utility model.

[0020] In the diagram: 1. Pipe sheath; 2. Insulation layer; 3. Wear-resistant layer; 4. Sensor data cable; 5. Anchor; 501. Anchor rod; 502. Anchor base; 6. Temperature sensor; 601. Sensor 1; 602. Sensor 2; 603. Sensor 3; 604. Sensor 4. Detailed Implementation

[0021] To make the above-mentioned objectives, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0022] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0023] See attached document Figure 1 -Appendix Figure 4 This system monitors the real-time loss of insulation layers in insulated pipes, including flue gas ducts, nano-insulation layers, aluminum silicate insulation layers, and wear-resistant layers. Anchors are evenly distributed along the flue to secure the insulation layer to the inner wall of the pipe.

[0024] The thickness of the nano-insulation layer inside the flue gas duct is 10-50mm. The thickness of the aluminum silicate insulation layer inside the flue gas duct is 10-50mm. The thickness of the wear-resistant layer inside the flue gas duct is 150mm. The thermal conductivity of the composite insulation layer nano-insulation material is 0.01-0.03W / (m·K).

[0025] The technical solution of this utility model is to fix anchors on the inner wall of the pipe. The anchors are "V" shaped and have special anchors (anchors capable of detecting temperature) spaced apart. The specific structure is hollow. Temperature sensors, numbered 1-4, are placed at different heights on the anchors. The temperature sensors are thermocouples with a temperature range of -270℃ to 1800℃, which can realize real-time monitoring of the temperature inside the pipe. Temperature sensor 1 is located on the inner wall of the pipe. Temperature sensor 2 is located 10-50mm away from the wall inside the pipe, at the interface between the nano-insulation layer and the aluminum silicate insulation layer. Temperature sensor 3 is located 10-50mm away from the wall inside the pipe, at the interface between the aluminum silicate insulation layer and the wear-resistant layer. Temperature sensor 4 is located outside the wear-resistant layer in direct contact with the flue gas.

[0026] The anchors of this invention are evenly distributed, with the "V"-shaped anchors arranged in the same direction and spaced 200mm apart. Specifically, hollow "V"-shaped anchors are specially incorporated into the "V"-shaped anchors, evenly distributed at bends and horizontal sections of the high-temperature hot air duct. Taking the bend as an example, the "V"-shaped anchors are evenly distributed with a 200mm interval. Within a 1m... 2 Approximately 36 anchors are installed internally, with seven hollow anchors spaced 600mm apart at the center. These hollow anchors are labeled V1, V2, V3, and V4. Temperature sensors are installed on the anchors to record temperature data in real time, denoted as TV1, TV2, TV3, and TV4. The average temperature values ​​collected by sensors 1-4 at four points are recorded as T1, T2, T3, and T4.

[0027] This invention uses temperature sensors to obtain the temperature of the pipe insulation layer in real time. Four hollow anchors, each spaced one meter apart and equipped with a temperature sensor, are used to collect temperature values ​​at four points, and the computer automatically calculates the average temperature. The average temperature values ​​of sensors 1-4 are denoted as T1, T2, T3, and T4. The ambient temperature is denoted as ta, the temperature of the medium inside the pipe is denoted as t, and the temperature of the outer wall of the pipe is ts. The physical properties of each insulation layer are known in the system, including the thermal conductivity from the inner wear-resistant layer to the pipe skin, denoted as λ1, λ2, and λ3 respectively, and the pipe diameter from the inside to the outside, denoted as D0, D1, D2, and Dw respectively. The thermal resistance of the single-layer insulation material from the inside to the outside is denoted as R1, R2, and R3, and the convective and radiative thermal resistance of the outer wall of the pipe is denoted as Rh. The heat loss per unit pipe can be calculated by collecting temperature data, using formula (3).

[0028]

[0029] in The radiative heat transfer coefficient of the pipe surface, W / m 2 ·K;

[0030] The convective heat transfer coefficient of the pipe surface, W / m 2 ·K;

[0031] Heat loss due to pipe insulation, W / m;

[0032] The outer surface temperature of the pipe is ℃;

[0033] The ambient temperature is in °C.

[0034] For pipe opacity;

[0035] λ1, λ2, and λ3 are the thermal conductivity of the inner wear-resistant layer, the insulation layer, and the pipe skin, respectively, in W / m·K.

[0036] D0, D1, D2, D W These are the inner diameter of the high-temperature flue, the outer diameter of the wear-resistant layer of the high-temperature flue, the outer diameter of the insulation layer of the high-temperature flue, and the outer diameter of the high-temperature flue, respectively, in mm.

[0037] The following is a further detailed description of this application: This utility model sets up a composite insulation structure based on nano-insulation materials. Taking a certain flue gas pipeline as an example, the original pipeline insulation material is 50mm aluminum silicate fiber blanket and 150mm thick refractory castable for wear resistance. The flue gas temperature is 300℃. Formula (1)-(3) calculates that the wall temperature under this condition is 59℃ and the heat loss is 3066W / m. When using nano-insulation materials with a thickness of 10mm, the pipe wall temperature is 51℃ with 40mm aluminum silicate fiber blanket and 150mm thick refractory castable for wear resistance. When using nano-insulation materials with a thickness of 20mm, the pipe wall temperature is 46℃ with 30mm aluminum silicate fiber blanket and 150mm thick refractory castable for wear resistance. When using nano-insulation materials with a thickness of 50mm, the pipe wall temperature is 39℃ with 0mm aluminum silicate fiber blanket and 150mm thick refractory castable for wear resistance.

[0038] In practice, the inner layer of the pipe will wear down due to the scouring effect of flue gas, meaning the thickness of the wear-resistant layer gradually decreases from D1 to D0. Based on the principle of thermal balance, the heat flux density through each layer is the same under steady state. The theoretical heat loss of the insulation structure can be calculated by recording the flue gas temperature and ambient temperature inside the pipe. This utility model patent calculates the wear of the wear-resistant layer based on the principle of thermal balance by real-time monitoring of the temperature between the insulation layers, as well as the flue gas temperature, ambient temperature, and the inner and outer surface temperatures of the insulation layer. The specific operation is as follows: After the insulation layer is installed and the pipe is started normally, the theoretical heat loss q is calculated based on the flue gas temperature and ambient temperature. L During normal production, real-time temperature data is collected and recorded for the inner and outer surfaces of the insulation layer. Calculate the thermal resistance of the insulation layer The actual heat loss is By comparison To determine the wear condition of the wear-resistant layer, calculate the wear resistance layer using formulas (1) to (3). This allows for the determination of the actual thickness of the wear-resistant layer, enabling real-time monitoring of its wear status.

[0039] This invention proposes a composite internal insulation structure based on nano-insulation materials. Specifically, the structure consists of a layer of nano-insulation material on the inner wall of the pipe, a layer of aluminum silicate insulation cotton on the inner surface of the nano-insulation material, and a layer of refractory castable on the innermost side of the pipe. The insulation layers are connected by V-shaped anchors, with each anchor spaced 200mm apart. A hollow anchor with a thermal sensor is specifically included, with the sensor located at the joint of each insulation layer, designated as sensor 1-4. The anchors are spaced 1m apart. 2 Four hollow anchors with thermal sensors are installed inside. The data from the four sensors is collected and the average value is taken as the temperature of each layer of sensors in this area. A signal acquisition cable is installed every meter in the pipeline to collect the thermal sensor signals.

[0040] This invention provides a composite insulation structure based on nano-insulation materials, which offers superior insulation performance compared to conventional aluminum silicate materials. Furthermore, to address the wear of the wear-resistant layer within the insulation layer, an anchor with a temperature sensor is incorporated. These anchors are spaced apart to enable real-time monitoring and control of the temperature between the insulation layers. The wear condition of the wear-resistant layer is calculated through real-time temperature monitoring, comparison, and analysis.

[0041] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. An insulated pipe for real-time monitoring of insulation layer loss, comprising a pipe skin (1), wherein an insulation structure is provided inside the pipe skin (1), characterized in that: The insulation structure includes a wear-resistant layer (3) and an insulation layer (2) located between the wear-resistant layer (3) and the tube skin (1). The insulation layer (2) includes a nano-insulation layer and an aluminum silicate insulation layer. Both the wear-resistant layer (3) and the insulation layer (2) are annular structures and completely fill the inner wall of the tube skin (1). Multiple anchors (5) are embedded inside the insulation layer (2) and the wear-resistant layer (3). Temperature sensors (6) are provided on the surface of the anchors (5). The anchors (5) are located in the horizontal section of the insulation layer (2) and the wear-resistant layer (3) and extend to both sides. The axis of the tube skin (1) is perpendicular to the above-mentioned horizontal section. Multiple temperature sensors (6) are arranged along the length direction of the anchors (5). Multiple temperature sensors (6) are electrically connected to a central processing unit through a sensor data cable (4) on the outside of the tube skin (1).

2. The insulated pipeline for real-time monitoring of insulation layer loss according to claim 1, characterized in that, The anchor (5) is V-shaped and includes two cross-arranged anchor rods (501), and multiple temperature sensors (6) extend along the length of the anchor rods (501).

3. The insulated pipeline for real-time monitoring of insulation layer loss according to claim 2, characterized in that, The anchor (5) also includes an anchor base (502), which is detachably connected to the intersection of the two anchor rods (501) and is located on the side close to the tube (1).

4. The insulated pipeline for real-time monitoring of insulation layer loss according to claim 1, characterized in that, The plurality of temperature sensors (6) are arranged at equal intervals along the length of the anchor (5).

5. The insulated pipeline for real-time monitoring of insulation layer loss according to claim 1, characterized in that, Multiple anchors (5) and temperature sensors (6) are arranged equidistantly around the circumference of the pipe (1). The number of temperature sensors (6) is less than the number of anchors (5). There are several anchors (5) between two adjacent temperature sensors (6).

6. The insulated pipeline for real-time monitoring of insulation layer loss according to claim 1, characterized in that, The thickness of the nano-insulation layer and the aluminum silicate insulation layer is 10-50mm respectively.

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