Temperature measurement optical fiber protection cylinder

Abstract

The utility model relates to a temperature measurement optical fiber protection cylinder, which structurally comprises an inner wall, a connecting piece A, a connecting piece B, a reaction ball A, a reaction ball B, a reaction film and an outer wall, the inner wall and the outer wall are both circular sections, the inner wall is smooth and continuous, and the outer wall is continuous in grids; the inner wall, the outer wall, the connecting piece A and the connecting piece B are all made of PE materials and have the characteristics of acid and alkali resistance and high temperature resistance; the connecting piece A and the connecting piece B are used for keeping the shape of the pile casing stable; the reaction film can react with a strongly acidic solution to form holes to promote the solution to enter the interior and react with the reaction balls rapidly to release heat, and the temperature of the optical cable is increased and maintained for a period of time; the DTS can timely position the leakage position and give an alarm according to the temperature rise of the optical fiber; and the reaction film does not react with a low-concentration acid solution, so that false alarms caused by interference of weak acid rainwater are avoided. The reaction balls can be replaced after being used, material waste is reduced, and the utilization rate is increased.

Description

Technical Field

[0001] The utility model relates to a temperature measuring optical fiber sheath, in particular to a temperature measuring optical fiber sheath which can be used to detect whether a leakage occurs in an acidic solution conveying pipeline. Background Technique

[0002] With the rapid development of China's economy, the increasing improvement of people's living quality, the continuous increase of the urbanization rate, and the continuous expansion of industrial production, pipeline transportation has become an indispensable part of people's lives. However, pipeline leakage has always been a difficult and key point in the safe operation of pipelines. Once a pipeline is damaged, especially an acidic solution transportation pipeline, it will not only cause huge resource waste and serious economic losses to society, but even endanger people's lives. Therefore, closely monitoring the operation status of pipelines to ensure the healthy development of the people's economy is of great significance. Distributed optical fiber sensing technology has become a research hotspot in recent years due to its own advantages such as long sensing distance, high spatial resolution, high insulation, high sensitivity, accurate positioning, anti-magnetic interference, safety and reliability, and has received more and more attention from researchers. Among them, the distributed optical fiber temperature sensing system (Distributed Temperature Sensing, DTS) is based on the temperature-sensitive characteristics of the spontaneous Raman scattering effect generated when laser propagates in the optical fiber and the optical time domain reflectometry technology to achieve accurate temperature measurement and precise positioning of temperature abnormal points. Generally, the distributed optical fiber temperature sensing system cannot be used for the detection and positioning of acidic solution leakage. Because when a leakage occurs in an acidic solution pipeline, the general distributed optical fiber temperature sensing system will not have a temperature change at the leakage point, and it cannot timely locate the leakage point and issue an alarm.

[0003] Currently, in the patent literature of China, some detection methods for the leakage of acidic medium pipelines can be seen. By designing a special self-sensing optical cable, the leakage detection of acidic medium pipelines can be realized. For example, by the exothermic reaction of the acidic medium and the outer sheath to create a temperature difference at the leakage point (publication number: CN111090153A, title: "A self-sensing optical cable and its application for detecting the leakage of acidic medium pipelines").

[0004] Although the above scheme can realize the leakage detection of acidic medium pipelines, the outer sheath that reacts with the acidic medium is integrated with the optical fiber, and there is a disadvantage of single leakage point detection at one time, which is easy to cause waste of resources and cannot make efficient use of the sensing optical fiber. Moreover, for micro-leakage, there are problems such as too small reaction area between the outer sheath and the acid solution, too low heat released by the reaction, and too short length of the optical fiber with temperature change. Due to the limitation of the spatial resolution of the distributed optical fiber temperature sensing system, the temperature change of the short-distance optical fiber cannot be detected by the system in time, and there are problems such as missed detection and false alarm in actual engineering applications. Summary of the Invention

[0005] To solve the problems of leakage detection of acidic solution pipelines at room temperature and replacement of detection substances, the utility model provides a temperature-measuring optical fiber sheath that is suitable for leakage detection of acidic solutions and can be disassembled and replaced. By adopting the distributed optical fiber temperature measurement technology, the problems of leakage detection and positioning warning of acidic solutions in long-distance transportation are solved. By adopting a detachable sheath structure, the problems of single-point leakage detection at one time and replacement of detection substances are solved, and the digital intelligent safety monitoring level of pipelines is further improved.

[0006] The purpose of the utility model is to provide a temperature-measuring optical fiber sheath for detecting leakage of acidic solution pipelines, so as to solve some deficiencies existing in the application of distributed optical fiber temperature measurement technology in leakage detection of acidic solutions transported in pipelines at room temperature.

[0007] The technical solution adopted by the utility model to solve the above problems is as follows: a temperature-measuring optical fiber sheath, which is a cylindrical hollow structure, and from the inside to the outside are an inner wall, a connecting piece A, a connecting piece B, a reaction ball A, a reaction ball B, a reaction film and an outer wall in sequence; the cross-section of the inner wall is a smooth continuous cross-section, and the cross-section of the outer wall is a grid continuous cross-section.

[0008] Preferably, the preparation material of the reaction ball A includes calcium hydroxide, and the preparation raw materials of the reaction ball B include iron powder, activated carbon, inorganic salts, vermiculite, water-absorbing resin, and peg4000. The diameter sizes of the reaction ball A and the reaction ball B are larger than the diameter size of the outer wall grid, preventing the reaction balls from slipping out of the outer wall grid, and the reaction ball A and the reaction ball B are evenly placed between the inner wall and the outer wall.

[0009] Preferably, the inner wall (1) is made of PE material, and its cross-section is a smooth continuous cross-section; the connecting piece A (3a) and the connecting piece B (3b) are made of PE material, connecting the inner wall and the outer wall to keep the structural shape stable; the outer wall (2) is made of PE material, and its cross-section is a grid continuous cross-section, facilitating strong acid solution to enter between the inner wall and the outer wall and react smoothly with the reaction ball A (5a).

[0010] Preferably, the material of the outer wall is PE material, and the diameter size of the outer wall grid is smaller than the diameter size of the reaction ball. The reaction film material attached to the outer wall is polycarbonate, which does not react in low-acid solutions and does not produce holes;

[0011] Optionally, the reaction film material attached to the outer wall has good tolerance to weak acids.

[0012] Optionally, the outer wall reaction film has good tolerance to weak acids. After contacting with a hydrochloric acid solution with a concentration of more than 20%, pores can be quickly formed, enabling the subsequent hydrochloric acid solution to smoothly enter the space between the inner wall and the outer wall and rapidly react with the reaction spheres A therein, releasing a large amount of heat. When the outer wall reaction film contacts with a hydrochloric acid solution with a concentration of less than 20%, no reaction occurs. Controlling the material of the outer wall reaction film to only react with solutions of a specific acidity can reduce false alarms caused by influencing factors such as acid rain and improve the accuracy of detecting acid solution leakage.

[0013] For the application of the above temperature-measuring optical fiber sheath in detecting acid solution leakage, the sheath is wound around the acid solution conveying pipeline or fixed on the outer wall of the acid solution conveying pipeline. When the pipeline leaks, the reaction film pasted on the outer wall of the sheath will react with it to form pores. The strong acid solution passes through the pores and reacts with calcium hydroxide in the reaction sphere A, releasing a large amount of heat. The outer film of the reaction sphere B melts when encountering high temperature, and the exposed iron powder will react with oxygen and water in the air, releasing a large amount of heat, causing the local temperature of the optical fiber at the leakage point to rise rapidly. After being monitored by the optical fiber temperature measurement system DTS, the leakage position is located and an alarm is issued.

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

[0015] (1) By using the reaction film on the outer wall of the optical fiber sheath to react with the acid solution to form pores, the strong acid solution passes through the pores and reacts with calcium hydroxide in the reaction sphere A, releasing a large amount of heat. The outer film of the reaction sphere B melts when encountering high temperature, and the exposed iron powder will react with oxygen and water in the air, releasing a large amount of heat, causing the local temperature of the optical fiber at the leakage point to rise rapidly. The principle is simple and the detection accuracy is high; (2) The optical fiber sheath protects the optical fiber in sections, and the length of each sheath is about 1 m. After the reaction substances in the optical fiber sheath react with the acid solution, the sheath can be replaced to repeatedly monitor a single leakage point, improving the utilization efficiency of the optical fiber; (3) After the reaction sphere A in the present application reacts with the acid solution, a large amount of heat can be released, causing the outer film of the reaction sphere B to melt, exposing the iron powder in the reaction sphere B. The iron powder then reacts with oxygen and water in the air, releasing a large amount of heat. Other reaction spheres B are similar, thus forming a chain reaction, lengthening the length of the optical fiber with temperature changes, and avoiding false alarms caused by the limitation of too small spatial resolution; (4) The optical fiber sheath of the present application can quickly react with hydrochloric acid, sulfuric acid or nitric acid of a certain concentration, causing the local temperature of the optical fiber to rise rapidly, and the reaction is highly targeted; (5) The reaction film on the outer wall of the sheath has good tolerance to weak acids and does not react with acid solutions with a concentration of less than 20%, reducing the influence of interference factors such as acid rain and improving the accuracy of acid solution leakage monitoring. Description of the Drawings

[0016] Figure 1 is the plan view after the temperature - measuring optical fiber casing of the present utility model is closed;

[0017] Figure 2 is the three - dimensional view after the temperature - measuring optical fiber casing of the present utility model is closed;

[0018] Figure 3 is the schematic diagram of the casing buckle of the temperature - measuring optical fiber casing of the present utility model;

[0019] Figure 4 is the schematic diagram of the buckle and snap ring of the temperature - measuring optical fiber casing of the present utility model;

[0020] Figure 5 is the schematic diagram of the reaction ball and connecting piece of the temperature - measuring optical fiber casing of the present utility model;

[0021] Figure 6 is the developed view of the outer wall grid of the temperature - measuring optical fiber casing of the present utility model Detailed implementation manners

[0022] The present utility model will be further described in detail below in conjunction with the embodiments in the drawings. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions from beginning to end. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present utility model, and should not be construed as limiting the present utility model.

[0023] The terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present utility model, the meaning of "a plurality" is two or more, unless otherwise specifically and clearly defined.

[0024] In the present utility model, unless otherwise clearly specified and limited, the terms such as "installation", "connection", "connection", "fixation" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0025] Such as Figure 1 and 2As shown in the figure, this embodiment relates to a temperature-measuring optical fiber casing, and particularly to a temperature-measuring optical fiber casing for monitoring the leakage of an acidic solution conveying pipeline. From the inside to the outside, it includes an inner wall (1), a connector A (3a), a connector B (3b), a reaction ball A (5a), a reaction ball B (5b), a reaction film (4), and an outer wall (2). The cross-sections of the inner wall (1) and the outer wall (2) are both circular. The cross-section of the inner wall is a smooth continuous cross-section, and the cross-section of the outer wall is a grid continuous cross-section. The reaction balls A (5a) and B (5b) are evenly distributed between the inner wall and the outer wall. The connectors A (3a) and B (3b) are staggered between the inner wall and the outer wall. The reaction film (4) is tightly pasted inside the outer wall (2) to prevent foreign objects from blocking the grid holes of the outer wall.

[0026] The material of the above reaction film has good tolerance to weak acids and is composed of polycarbonate. The reaction film can react with hydrochloric acid solution above 20%. After the polycarbonate is corroded by hydrochloric acid, holes are formed on the reaction film. Hydrochloric acid enters between the inner wall and the outer wall along the holes and quickly releases heat through the neutralization reaction with calcium hydroxide in the reaction ball A. After the reaction ball B encounters high temperature, it melts, and the exposed iron powder undergoes a reduction reaction with water and oxygen in the air, quickly releasing a large amount of heat. Other reaction balls B are similar, thus forming a chain reaction, which causes the temperature of the optical fiber inside this section of the optical fiber casing to rise rapidly.

[0027] The reaction film on the outer wall also has the effects of preventing ultraviolet aging and flame retardancy, and the neutralization reaction and redox reaction will not cause a fire.

[0028] Both the inner wall and the outer wall of the optical fiber temperature-measuring casing are made of PE plastic material, which has good corrosion resistance and high temperature resistance. When repeatedly monitoring a single measurement point, only the optical fiber casing that has participated in the reaction needs to be replaced, and the operation is simple, energy-saving, and environmentally friendly.

[0029] The application of the optical fiber temperature-measuring casing in this embodiment: Place the optical fiber in the optical fiber temperature-measuring casing and make them closely connected to form a whole. Then arrange this whole of equal length on the outer wall of the conveying pipeline. When local leakage occurs in the conveying pipeline, the leaked acidic solution reacts with the reaction substances in the optical fiber casing. The reaction releases heat, causing the local temperature of the optical fiber inside the optical fiber casing to rise rapidly. The distributed optical fiber temperature measurement system DTS can measure the temperature change of the optical fiber at the acidic solution leakage point by Raman scattering and optical time domain reflectometry technology and can accurately monitor the location of the acidic solution leakage.

[0030] For the optical fiber temperature measurement protection cylinder with the above structure, the reaction film pasted on the outer wall is made of a material that can react with strong acid media. It can react with an acidic solution of a certain concentration within a short time to form holes, enabling the subsequent acidic solution to smoothly enter the protection cylinder, rapidly react with the reaction substances in the protection cylinder to release heat, causing the local optical fiber temperature to rapidly rise and maintain for a period of time. The reaction film does not react in a low-concentration acidic solution, maintaining the weak acid resistance and flame retardant properties of the protection cylinder. The optical fiber temperature measurement system DTS can accurately detect the solution leakage in the acidic solution conveying pipeline based on the temperature change at the local optical fiber. Moreover, due to the weak acid resistance of the reaction film, it can effectively avoid the influence of interference factors such as weak acid rain on the leakage detection.

[0031] Although the preferred embodiments of the present invention have been described in detail above, it should be clearly understood that various modifications and changes can be made to the present invention for those skilled in the art. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A temperature measuring optical fiber protective sleeve, which is a cylindrical hollow structure, characterized in that: From the inside to the outside, they are the inner wall (1), the connecting piece A (3a), the connecting piece B (3b), the reaction ball A (5a), the reaction ball B (5b), the reaction membrane (4), and the outer wall (2); the cross-sections of the inner wall (1) and the outer wall (2) are both circular, the inner wall cross-section is a smooth continuous cross-section, and the outer wall cross-section is a grid continuous cross-section.

2. The temperature measuring optical fiber sheath according to claim 1, characterized in that: The inner wall (1) is made of PE material and has a smooth continuous cross section; the connector A (3a) and the connector B (3b) are made of PE material and connect the inner wall and the outer wall to maintain the stability of the structural shape; the outer wall (2) is made of PE material and has a grid continuous cross section, which facilitates the strong acid solution to enter between the inner wall and the outer wall and react smoothly with the reaction ball A (5a).

3. The temperature measuring optical fiber sheath according to claim 1, characterized in that: The outer wall (2) is a continuous grid section, the size of the grid being smaller than the size of the reaction ball, thereby preventing the reaction ball from slipping out of the casing through the grid.

4. The temperature measuring optical fiber sheath according to claim 1, characterized in that: The raw material for preparing the reaction membrane (4) is polycarbonate.

5. The temperature measuring optical fiber sheath according to claim 2, characterized in that: The raw materials for preparing the reaction ball A (5a) include calcium hydroxide; the raw materials for preparing the reaction ball B (5b) include iron powder, activated carbon, inorganic salt, vermiculite, water-absorbing resin, and PEG4000.

6. The temperature measuring optical fiber protective sleeve according to claim 2, characterized in that: The reaction ball A (5a) can react quickly with the strong acid solution, releasing a large amount of heat, causing the local temperature to rise. The outer membrane of the reaction ball B (5b) will quickly dissolve under high temperature conditions. After the outer membrane of the reaction ball B (5b) dissolves, the exposed iron powder will quickly react with oxygen and water in the air, releasing a large amount of heat, causing the local temperature to rise, so that the optical fiber temperature measurement system DTS can successfully detect the temperature change.

7. The temperature measuring optical fiber sheath according to claim 1, characterized in that: The reaction membrane (4) does not react in a low-acid solution and does not generate holes; the reaction membrane does not react under the interference of acid rain, thereby reducing the false alarm rate of the system.

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