An online leak detection bellows compensator and leak detection method for high temperature applications

Abstract

The present invention belongs to the field of intelligent industrial pipeline technology, and specifically relates to an online leak detection bellows compensator and a leak detection method for high temperature occasions. The compensator includes a bellows, an external insulation structure with variable length, at least two temperature sensors, a data processing device and a terminal display device. The bellows is connected to the detection pipeline, and the external insulation structure is arranged on the outside of the bellows. The detection pipeline, the outer wall of the bellows, and the external insulation structure form a circumferential insulation cavity. The probe of at least one temperature sensor extends into the insulation cavity, and the probe of at least one temperature sensor extends into the inside of the detection pipeline. The temperature sensor is connected to the data processing device, and the data processing device is connected to the terminal display device. The present invention monitors in real time whether the bellows compensator leaks from the system pressure test after the pipe network is installed to the long-term working state, and can continue to operate safely after the online leakage report, providing sufficient decision-making and maintenance time for the pipe network manager.

Description

Technical Field

[0001] The invention belongs to the technical field of intelligent industrial pipelines, and in particular relates to an online leak detection bellows compensator and a leak detection method for high temperature applications. Background Art

[0002] As a common flexible element in pipeline design, bellows compensator mainly compensates for the displacement of pipeline caused by temperature change. In high-temperature medium occasions, the temperature difference is large, and the thermal expansion and contraction of the pipeline are obvious. Bellows compensator plays a vital role, so it is widely used, such as hot blast furnace pipelines in steel plants (medium temperature is about 1300℃) or regeneration inclined pipes and flue gas energy recovery systems in the petrochemical industry (medium temperature is about 700℃). In high-temperature occasions, once the working medium in the pipe leaks, it may cause economic losses or personal injuries. Therefore, it is necessary to take measures to prevent the leakage of bellows compensators and improve their safety in use.

[0003] In order to improve flexibility, bellows are mostly thin-walled structures. The circumferential welds connected to the pipeline under high temperature conditions are weak links and are prone to cracking, leading to leakage. The traditional method is generally to find the leak point one by one by opening the valves in sections after discovering that the pressure in the pipeline is unstable. The operation of the equipment in the pipeline system is often closely linked. If the equipment is shut down, it will cause great losses. Therefore, the equipment is generally not shut down, and the leak is temporarily blocked by spraying refractory mud. The bellows compensator here is replaced when the equipment is overhauled. There are often a large number of bellows compensators on the high-temperature pipelines of complex systems. The equipment is not shut down. The uninterrupted inspection of the bellows compensators on the complex high-temperature pipelines can neither find the bellows compensators at the leaking places in time, nor can it increase the labor intensity of the operation and maintenance personnel, and increase safety hazards, which need to be solved. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides an online leak detection bellows compensator and a leak detection method for use in high temperature occasions, which can monitor in real time whether there is leakage in the bellows compensator from the system pressure test after the pipeline network is installed to the long-term working state, and can continue to operate safely after reporting the leakage online, providing pipeline managers with sufficient decision-making and maintenance time.

[0005] The present invention is implemented in this way. It provides an online leak detection bellows compensator for use in high-temperature occasions, including a bellows, an external insulation structure with variable length, at least two temperature sensors, a data processing device and a terminal display device. The bellows is connected to the detection pipeline, and the external insulation structure is arranged on the outside of the bellows. One end of the external insulation structure is fixedly connected to the detection pipeline on one side of the bellows, and the other end of the external insulation structure is fixedly connected to the detection pipeline on the other side of the bellows. The detection pipeline, the outer wall of the bellows, and the external insulation structure form a circumferential insulation cavity. The probe of at least one temperature sensor extends into the insulation cavity, and the probe of at least one temperature sensor extends into the inside of the detection pipeline. The temperature sensor is connected to the data processing device, and the data processing device is connected to the terminal display device.

[0006] Preferably, the outer insulation structure includes a first outer insulation ring structure and a second outer insulation ring structure, one end of the first outer insulation ring structure is fixedly connected to the detection pipeline on one side of the bellows, one end of the second outer insulation ring structure is fixedly connected to the detection pipeline on the other side of the bellows, and the other end of the first outer insulation ring structure is staggered and inserted with the other end of the second outer insulation ring structure to form an outer insulation structure with variable length.

[0007] Further preferably, the first outer insulation ring structure is closer to the bellows than the second outer insulation ring structure, and a flexible metal mesh sleeve is fixedly disposed on one end of the first outer insulation ring structure and the second outer insulation ring structure that are staggered and inserted into each other.

[0008] Further preferably, an inner insulation layer is provided on the inner wall of the detection pipeline.

[0009] Further preferably, the position where the online leak detection bellows compensator is installed in the detection pipeline is a reducing pipeline, the bellows is installed in the reducing section of the reducing pipeline, one end of the external insulation structure is connected to the reducing section on one side of the reducing pipeline, and the other end is connected to the reducing section on the other side of the reducing pipeline.

[0010] Further preferably, the position where the online leak detection bellows compensator is installed in the detection pipeline is a straight pipeline, the bellows is connected to the straight pipeline, and fixing rings are respectively provided on the straight pipelines on both sides of the bellows, one end of the external insulation structure is connected to the fixing ring on one side of the straight pipeline, and the other end is connected to the fixing ring on the other side of the straight pipeline, and an insulation cotton layer is provided on the outer side of the two fixing rings away from the insulation cavity.

[0011] The present invention also provides a method for leak detection using the above-mentioned online leak detection bellows compensator for high temperature applications, comprising the following steps:

[0012] 1) Air tightness test of bellows compensator;

[0013] 2) Calibrate and debug the temperature sensor, data processing equipment and terminal display equipment;

[0014] 3) Turn on the temperature sensor, data processing equipment and terminal display equipment. The temperature sensor with a probe in the insulation cavity monitors the maximum temperature value T0 in the insulation cavity of the bellows compensator in real time, and sends the temperature signal to the data processing equipment. The probe is located in the detection pipeline to monitor the medium temperature value T in the detection pipeline in real time, and sends the temperature signal to the data processing equipment. The data processing equipment compares the data and sends the final result to the terminal display equipment;

[0015] 4) When the temperature value of the insulation chamber rises rapidly and the monitored temperature value T0 is close to the temperature value T of the medium in the pipeline, the terminal display device issues a leakage alarm for the bellows compensator at this position.

[0016] Compared with the prior art, the advantages of the present invention are:

[0017] The present invention solves the problem of rapid positioning and alarming of leaking bellows compensators in a complex high-temperature pipe network containing multiple bellows compensators without stopping the equipment, so that management personnel can take timely measures. Remote online monitoring is achieved, and there is no need for operation and maintenance personnel to conduct frequent inspections of bellows compensators, reducing labor costs. The bellows compensator has secondary protection after the high-temperature medium leaks, avoiding direct damage to personnel and the external environment by the high-temperature medium. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A structural diagram of an online leak detection bellows compensator provided in Example 1 of the present invention;

[0019] Figure 2 This is a schematic diagram of the online leak detection bellows compensator provided in Example 1 of the present invention when the medium leaks.

[0020] Figure 3 This is a structural diagram of the online leak detection bellows compensator provided in Example 2 of the present invention. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention 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 invention and are not used to limit the present invention.

[0022] Embodiment 1,

[0023] refer to Figure 1The present invention provides an online leak detection bellows compensator for high temperature occasions, comprising a bellows 1, an external insulation structure with variable length, two temperature sensors 2, a data processing device 3 and a terminal display device 4, the bellows 1 is connected to a detection pipeline 5, an external insulation structure is arranged on the outside of the bellows 1, one end of the external insulation structure is fixedly connected to the detection pipeline 5 on one side of the bellows 1, and the other end of the external insulation structure is fixedly connected to the detection pipeline 5 on the other side of the bellows 1, the detection pipeline 5, the outer wall of the bellows 1 and the external insulation structure form a circumferential insulation cavity, the probe of at least one temperature sensor 2 extends into the insulation cavity, the probe of at least one temperature sensor 2 extends into the inside of the detection pipeline 5, the temperature sensor 2 is connected to the data processing device 3, and the data processing device 3 is connected to the terminal display device 4.

[0024] The position where the detection pipeline 5 is installed with the online leak detection bellows compensator is a reducing pipeline, the bellows 1 is installed in the reduced diameter section of the reducing pipeline, one end of the external insulation structure is connected to the reducing section on one side of the reducing pipeline, and the other end is connected to the reducing section on the other side of the reducing pipeline.

[0025] The temperature sensor 2 is a wireless intelligent temperature sensor, which realizes wireless transmission of temperature data, reduces complex wiring settings, facilitates equipment installation, and increases the reliability of sensor monitoring.

[0026] The method for leak detection using the above-mentioned online leak detection bellows compensator for high temperature applications comprises the following steps:

[0027] 1) Air tightness test of bellows compensator;

[0028] 2) Calibrate and debug the temperature sensor 2, data processing device 3 and terminal display device 4, and input the set threshold value [△T] of the difference between the temperature of the insulation cavity and the temperature of the medium in the pipeline into the program of the data processing device 3, and the threshold value needs to be determined through experiments;

[0029] 3) Turn on the temperature sensor 2, the data processing device 3 and the terminal display device 4. The temperature sensor 2 with a probe located in the insulation cavity monitors the maximum temperature value T0 in the insulation cavity of the bellows compensator in real time, and sends the temperature signal to the data processing device 3. The probe is located in the detection pipeline 5 to monitor the medium temperature value T in the detection pipeline 5 in real time, and sends the temperature signal to the data processing device 3. The data processing device 3 compares the data and sends the final result to the terminal display device 4. The temperature difference value △T=T-T0<[△T] between the two is calculated by the program as the alarm basis of the terminal display device;

[0030] 4)Reference Figure 2When the bellows compensator leaks, the high-temperature medium in the pipeline quickly rushes into the insulation cavity under pressure, forming strong convection in a limited space, causing the air temperature in the insulation cavity to rise sharply in a short period of time. By monitoring the instantaneous sharp increase in the air temperature in the insulation cavity and approaching the medium temperature in the pipeline, the terminal display device 4 issues a leakage alarm for the bellows compensator at this position to ensure that the location of the leaking bellows compensator in the pipeline is discovered in time. When a high-temperature medium leaks, the presence of the external insulation structure also avoids direct damage to personnel and the external environment by the high-temperature medium.

[0031] As a specific implementation mode of the external insulation structure, the external insulation structure includes a first external insulation ring structure 6 and a second external insulation ring structure 7, one end of the first external insulation ring structure 6 is fixedly connected to the detection pipeline 5 on one side of the bellows 1, one end of the second external insulation ring structure 7 is fixedly connected to the detection pipeline 5 on the other side of the bellows 1, and the other end of the first external insulation ring structure 6 and the other end of the second external insulation ring structure 7 are staggered and inserted into each other to form an external insulation structure with variable length.

[0032] The staggered and plugged structure of the two insulation rings of the outer insulation structure can ensure that the bellows can move freely along the axial direction to compensate for the thermal displacement of the pipeline. The first outer insulation ring structure 6 and the second outer insulation ring structure 7 are filled with insulation material, which can be common aluminum silicate insulation cotton.

[0033] In order to prevent the insulation material at the end of the first outer insulation ring structure 6 from falling into the insulation cavity, as an improvement of the technical solution, the first outer insulation ring structure 6 is closer to the corrugated pipe 1 than the second outer insulation ring structure 7, and a flexible metal mesh sleeve 8 is fixedly disposed at one end of the first outer insulation ring structure 6 and the second outer insulation ring structure 7, which are staggered and inserted. The metal mesh sleeve 8 is fixed to the first outer insulation ring structure 6 by a mesh sleeve fixing element 11.

[0034] In order to do this, an inner insulation layer 9 is provided on the inner wall of the detection pipeline 5. When the bellows compensator is operating normally, the heat of the air in the insulation cavity mainly comes from the heat radiation of the outer wall of the bellows 1. The inner wall of the bellows 1 is provided with an inner insulation layer 9. When the high-temperature medium of the pipeline is operating normally, the temperature of the air in the insulation cavity will tend to a lower value. The insulation layer 9 is filled with insulation material. The selection of insulation material depends on the insulation requirements of the pipeline design, specifically the temperature of the internal medium. High temperature may require the use of refractory bricks or ceramic fiber materials. The ultimate goal is to prevent the temperature of the outer wall of the pipeline from being too high.

[0035] Embodiment 2,

[0036] refer to Figure 3The difference between this embodiment and embodiment 1 is that the position where the detection pipeline 5 is installed with the online leak detection bellows compensator is a straight pipeline, the bellows 1 is connected to the straight pipeline, and fixing rings 10 are respectively arranged on the straight pipelines on both sides of the bellows 1, one end of the external insulation structure is connected to the fixing ring 10 on one side of the straight pipeline, and the other end is connected to the fixing ring 10 on the other side of the straight pipeline, and a thermal insulation cotton layer is arranged on the outer side of the two fixing rings 10 away from the insulation cavity.

[0037] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention.

Claims

1. An online leak detection bellows compensator for high temperature applications, characterized in that: The invention comprises a bellows (1), an external insulation structure with a variable length, at least two temperature sensors (2), a data processing device (3) and a terminal display device (4); the bellows (1) is connected to a detection pipeline (5); the external insulation structure is arranged on the outside of the bellows (1); one end of the external insulation structure is fixedly connected to the detection pipeline (5) on one side of the bellows (1); the other end of the external insulation structure is fixedly connected to the detection pipeline (5) on the other side of the bellows (1); the detection pipeline (5), the outer wall of the bellows (1) and the external insulation structure form a circumferential temperature insulation cavity; the probe of at least one temperature sensor (2) extends into the temperature insulation cavity; the probe of at least one temperature sensor (2) extends into the interior of the detection pipeline (5); the temperature sensor (2) is connected to the data processing device (3); and the data processing device (3) is connected to the terminal display device (4); The outer thermal insulation structure comprises a first outer thermal insulation ring structure (6) and a second outer thermal insulation ring structure (7); one end of the first outer thermal insulation ring structure (6) is fixedly connected to the detection pipeline (5) on one side of the bellows (1); one end of the second outer thermal insulation ring structure (7) is fixedly connected to the detection pipeline (5) on the other side of the bellows (1); the other end of the first outer thermal insulation ring structure (6) and the other end of the second outer thermal insulation ring structure (7) are staggered and inserted into each other to form an outer thermal insulation structure with a variable length; The first outer insulation ring structure (6) is closer to the corrugated pipe (1) than the second outer insulation ring structure (7), and a flexible metal mesh sleeve (8) is fixedly provided at one end of the first outer insulation ring structure (6) and the second outer insulation ring structure (7) which are staggered and inserted into each other.

2. The online leak detection bellows compensator for high temperature applications according to claim 1, characterized in that: An inner thermal insulation layer (9) is provided on the inner wall of the detection pipeline (5).

3. The online leak detection bellows compensator for high temperature applications according to claim 1, characterized in that: The position where the detection pipeline (5) is installed with the online leak detection bellows compensator is a reducing pipeline, the bellows (1) is installed in the reduced diameter section of the reducing pipeline, one end of the external thermal insulation structure is connected to the reducing section on one side of the reducing pipeline, and the other end is connected to the reducing section on the other side of the reducing pipeline.

4. The online leak detection bellows compensator for high temperature applications according to claim 1, characterized in that: The position where the detection pipeline (5) is installed with the online leak detection bellows compensator is a straight pipeline, the bellows (1) is connected to the straight pipeline, and fixing rings (10) are respectively arranged on the straight pipelines on both sides of the bellows (1), one end of the external thermal insulation structure is connected to the fixing ring (10) on one side of the straight pipeline, and the other end is connected to the fixing ring (10) on the other side of the straight pipeline, and a thermal insulation cotton layer is arranged on the outer side of the two fixing rings (10) away from the thermal insulation cavity.

5. A method for leak detection using the online leak detection bellows compensator for high temperature applications as claimed in claim 1, characterized in that: The steps include: 1) Air tightness test of bellows compensator; 2) calibrating and debugging the temperature sensor (2), data processing equipment (3) and terminal display equipment (4); 3) Turn on the temperature sensor (2), the data processing device (3) and the terminal display device (4); the temperature sensor (2) with a probe located in the insulation cavity monitors the maximum temperature value T0 in the insulation cavity of the bellows compensator in real time, and sends the temperature signal to the data processing device (3); the probe is located in the detection pipeline (5) to monitor the temperature value T of the medium in the detection pipeline (5) in real time, and sends the temperature signal to the data processing device (3); the data processing device (3) compares the data and sends the final result to the terminal display device (4); 4) When the temperature value of the insulation chamber rises rapidly and the monitored temperature value T0 approaches the temperature value T of the medium in the pipeline, the terminal display device (4) issues a leakage alarm for the bellows compensator at this position.

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