A double-layer oil tank with online leak detection function and its detection and preparation process

Abstract

The present invention discloses a double-layer oil tank with an online leak detection function and a detection preparation process thereof, comprising an inner shell, an outer shell, and an intermediate layer between the inner shell and the outer shell; a detection tube is inserted into a guide tube to connect the intermediate layer, a detector is inserted into the detection tube, a plurality of optical fibers are evenly and tightly wound in the outer wall of the outer shell, and the ends of each optical fiber are led out from the contact point between the guide tube's wire groove and the outer shell, introduced into the guide tube through the wire groove and the threading notch, and then combined with the detector lead-out cable and led out through the lead-in hole. The present invention discloses a double-layer oil tank with an online leak detection function and a detection preparation process thereof, which can effectively distinguish the leakage of the inner shell and the outer shell, and can sense the leakage point when the leakage occurs.

Description

Technical Field

[0001] The invention relates to a double-layer oil tank with an online leak detection function and a detection and preparation process thereof, belonging to the technical field of oil tanks. Background Art

[0002] At present, double-layer oil tanks must have a leak detection function (used to detect leakage in the middle layer). The conventional leak detection methods are: sensor method (used for SF oil tanks), using a pressure sensor to detect the pressure of the middle layer; liquid medium method (used for FF oil tanks), brine is injected into the middle layer as a detection medium; vacuum method (used for FF oil tanks), the middle layer is evacuated to form a vacuum layer.

[0003] The present invention is based on SF oil tanks. In actual applications, it is found that the sensor of the SF oil tank can only detect whether leakage occurs, but it is impossible to timely and effectively distinguish whether the leakage point occurs in the outer shell or the inner shell, and it is even more impossible to effectively know where the cylinder leakage point occurs, so it is impossible to effectively evaluate its safety performance. Therefore, there are huge deficiencies and it is urgent to improve. Summary of the invention

[0004] The purpose of the present invention is to overcome the above-mentioned shortcomings and provide a double-layer oil tank preparation process with an online leak detection function, which can effectively distinguish the leakage of the inner shell and the outer shell, and can sense the position of the leakage point on the easily damaged cylinder when the leakage occurs.

[0005] The object of the present invention is achieved in that:

[0006] A double-layer oil tank with an online leak detection function, comprising an inner shell, an outer shell and an intermediate layer between the inner shell and the outer shell;

[0007] A guide tube is vertically welded on the top outer wall of the outer shell, a detection tube is inserted into the guide tube, passes through the top wall of the inner shell, and then abuts against the bottom inner wall of the inner shell, and a reinforcement ring is sleeved on the detection tube, the outer edge of the reinforcement ring is welded to the bottom inner wall of the inner shell, and the inner edge of the reinforcement ring is welded to the outer wall of the detection tube. A through hole is provided on a section of the inner shell located in the detection tube, and the detection tube is connected with the middle layer through the through hole; a wire groove is vertically provided on the lower outer wall of the guide tube, and the outer wall of the open end of the guide tube is recessed downward to form a threading notch, and the threading notch and the wire groove are located on the same straight line;

[0008] A detector is inserted into the detection tube, a locking ring is arranged on the top of the detector, the locking ring is arranged with an external thread, an internal thread is arranged on the top inner tube wall of the guide tube, the external thread of the locking ring is screwed on the internal thread of the guide tube, and the locking ring screwed into the guide tube is pressed against the top end surface of the detection tube;

[0009] The upper outer wall of the guide tube is provided with an external thread, the internal thread of the top cover is screwed onto the external thread of the guide tube, and the top cover is provided with a lead-in hole;

[0010] A plurality of optical fibers are evenly and tightly wound inside the outer wall of the outer shell, and both ends of each optical fiber are led out from the contact point between the wire groove of the guide tube and the outer shell, introduced into the guide tube through the wire groove and the threading notch, and then combined with the lead-out cable of the detector and led out through the lead-in hole.

[0011] A double-layer oil tank detection process with an online leak detection function, the steps are as follows:

[0012] One end of the multiple optical fibers is connected to the optical signal receiver, and the other end is divided into two paths after passing through an optical splitter. One path is connected to the optical signal generator, and the other is connected to the optical time domain reflectometer after passing through an optical switch.

[0013] When the detector detects no leakage signal, and the optical signal receiver receives the signal transmission between multiple optical fibers without delay or loss, it indicates that both the inner shell and the outer shell are in normal state;

[0014] When the detector detects a leakage signal, and the optical signal receiver receives the signal transmission between multiple optical fibers without delay or loss, it indicates that there is a leak in the inner shell;

[0015] When the detector does not detect a leakage signal, and the optical signal receiver receives a delayed or missing amount of a certain optical fiber among multiple optical fibers, the optical signal generator is controlled to stop working, the optical switch selects to conduct the link where the optical fiber is located, and the optical time domain reflectometer is started to obtain the distance S from the compression deformation point or break point of the optical fiber to the optical time domain reflectometer.

[0016] At this time, the outer diameter φ of the tightly wound optical fibers is known, the outer diameter D of the outer shell of the oil tank is known, and the distance L from the optical fiber lead-out point of the outer shell to the optical time domain reflectometer is known. The position of the leak point can be calculated to be (X, Y), where X is the axial distance between the radial plane where the leak point is located and the radial plane where the optical fiber and the outer shell contact, and Y is the arc angle of the radial plane where the leak point is located;

[0017] X=[(SL) / (Dπ+2φπ)]*φ;

[0018] Y={(SL)-[(SL) / (Dπ+2φπ)]*(Dπ+2φπ)} / (Dπ+2φπ);

[0019] When the detector detects a leakage signal and the optical signal receiver receives a delay or loss in signal transmission between multiple optical fibers, it appears that there are leaks in both the inner shell and the outer shell.

[0020] A double-layer oil tank inspection process with an online leak detection function, characterized in that:

[0021] Step 1: preparing and molding the inner shell;

[0022] Step 2: After the hole is opened on the top of the inner shell, the detection tube is inserted and a reinforcing ring is installed on one end of the detection tube located inside the inner shell;

[0023] Step 3, weld the bottom of the detection tube to the inner wall of the bottom of the inner shell, weld the outer edge of the reinforcement ring to the inner wall of the bottom of the inner shell, and weld the inner edge of the reinforcement ring to the outer wall of the detection tube; put a guide tube on the end of the top of the detection tube outside the inner shell, and the inner diameter of the guide tube is equal to the outer diameter of the detection tube, and weld the outer wall of the guide tube to the outer wall of the inner shell, and screw a top cover on the top open end of the guide tube;

[0024] Step 4: Drill a through hole on the bottom inner wall of the inner shell so that the through hole is connected to the detection tube;

[0025] Step 5: Laying an intermediate layer on the outer wall of the inner shell;

[0026] Step 6, the bottom glass fiber is wound outside the middle layer, and then the optical fiber is evenly and tightly wound on the bottom glass fiber to form the first detection optical fiber layer, and then the optical fiber is tightly wound again after the first detection optical fiber layer to form the second ranging optical fiber layer, and the second ranging optical fiber layer is only wound on the cylinder, and the end is not wound, and then the top cover is unscrewed, and the ends of the optical fiber are led out through the contact points between the wire groove of the guide tube and the outer shell, and then introduced into the guide tube through the wire groove and the threading notch, and then the top cover is screwed on; then the outer glass fiber is wound on the optical fiber for protection;

[0027] Step 7, unscrew the top cover, insert the detector into the detection tube, and screw the locking ring provided on the head of the detector into the guide tube and press it onto the end surface of the top opening of the detection tube;

[0028] Step 8: After the optical fiber introduced into the guide tube and the lead-out wire of the detector pass through the lead-in hole of the top cover, the top cover is screwed onto the guide tube, and then glass fiber paste is used to cure and seal the wire slot and the threading notch;

[0029] The present invention provides a double-layer oil tank detection process with an online leak detection function. In the optical fiber winding of the above step 6, the first layer of detection optical fiber is wound in three sections and then led out. The three sections are a left-to-multiple spiral winding section, a middle single winding section, and a right-to-multiple winding section; the middle single winding section is the optical fiber that starts from the contact point and is wound to the contact guide tube and then reversely wound to the contact guide tube again, and the reciprocating cycle is repeated until the space between the left-to-multiple spiral winding sections and the right-to-multiple winding sections is completely wound.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The present invention can conveniently identify where the leakage is inside and outside through the double-sided leak detection method, so as to facilitate the signing of responsibilities during and after the process of transforming conventional metal oil tanks into SF tanks; at the same time, when the outer tank is broken, the leakage point can be quickly determined, so as to make a safety judgment and quickly repair it, and the optical fiber adopts a multi-bundle surrounding structure, and the breakage of one bundle or a small number of bundles during the tank body rupture process will not affect its use after repair, but when a large number of leakage points appear and the OTDR cannot perform global effective detection, the optical fiber detection will fail, and the oil tank needs to be replaced as a whole or the outer shell needs to be replaced. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a schematic diagram of the structure of a double-layer oil tank with an online leak detection function according to the present invention (the optical fiber only illustrates the second layer of ranging optical fiber layer).

[0033] Figure 2 The present invention is a partial cross-sectional view of a double-layer oil tank with an online leak detection function.

[0034] Figure 3 and Figure 4 This is a schematic diagram of the parameters calculated for the present invention.

[0035] in:

[0036] Inner shell 1, outer shell 2;

[0037] Guide tube 101, detection tube 102, reinforcement ring 103, detector 104, locking ring 105, top cover 106;

[0038] Wire duct 101.1, wire threading notch 101.2;

[0039] Lead hole 106.1;

[0040] Fiber 201. DETAILED DESCRIPTION

[0041] See also Figure 1 and Figure 2The present invention relates to a double-layer oil tank with an online leak detection function, comprising an inner shell 1, an outer shell 2, and an intermediate layer between the inner shell 1 and the outer shell 2; a guide tube 101 is vertically welded on the top outer wall of the outer shell 2, a detection tube 102 is inserted into the guide tube 101, passes through the top wall of the inner shell 1, and then abuts against the bottom inner wall of the inner shell 1, and a reinforcement ring 103 is sleeved on the detection tube 102, and the outer edge of the reinforcement ring 103 is welded to the inner shell 1. On the inner wall of the bottom, the inner edge of the reinforcement ring 103 is welded to the outer wall of the detection tube 102. A through hole is provided on a section of the inner shell 1 located inside the detection tube 102, and the detection tube 102 is connected to the middle layer through the through hole; a wire groove 101.1 is vertically provided on the lower outer wall of the guide tube 101, and the outer wall of the open end of the guide tube 101 is concave downward to form a threading notch 101.2, and the threading notch 101.2 is located on the same straight line as the wire groove 101.1;

[0042] A detector 104 is inserted into the detection tube 102. A locking ring 105 is provided on the top of the detector 104. The locking ring 105 is provided with an external thread. The inner tube wall at the top of the guide tube 101 is provided with an internal thread. The external thread of the locking ring 105 is screwed onto the internal thread of the guide tube 101. The locking ring 105 screwed into the guide tube 101 is pressed against the top end surface of the detection tube 102, thereby fastening the detector 104 to prevent shaking.

[0043] The upper outer wall of the guide tube 101 is provided with an external thread, the internal thread of the top cover 106 is screwed onto the external thread of the guide tube 101, and the top cover 106 is provided with a lead-in hole 106.1;

[0044] A plurality of optical fibers 201 are evenly and tightly wound inside the outer wall of the outer shell 2, and the head and tail ends of each optical fiber 201 are led out from the contact point between the wire groove 101.1 of the guide tube 101 and the outer shell 2, introduced into the guide tube 101 through the wire groove 101.1 and the threading notch 101.2, and then combined with the lead-out cable of the detector 104 and led out through the lead-in hole 106.1;

[0045] When in use, one end of the multiple optical fibers 201 is connected to an optical signal receiver, and the other end is divided into two paths after passing through an optical splitter, one path is connected to an optical signal generator, and the other path is connected to an optical time domain reflectometer after passing through an optical switch, an optical time domain reflectometer (English name: optical time-domain reflectometer, OTDR);

[0046] When the detector 104 does not detect a leakage signal, and the optical signal receiver receives the signal transmission between the multiple optical fibers 201 without delay or loss, it indicates that the inner housing 1 and the outer housing 2 are both in a normal state;

[0047] When the detector 104 detects a leakage signal, and the optical signal receiver receives that there is no delay or loss in the signal transmission between the multiple optical fibers 201, it is apparent that there is a leakage point in the inner shell 1;

[0048] When the detector 104 does not detect a leakage signal, and the optical signal receiver receives a delayed or missing amount of a certain optical fiber among the multiple optical fibers 201, it indicates that only the outer shell 2 has a leak. At this time, the leak in the outer shell 2 has compressed or broken the optical fiber 201. At this time, the optical signal generator stops working, the optical switch selects to conduct the link where the optical fiber 201 is located, and the optical time domain reflectometer starts to obtain the distance S from the compression deformation point or break point of the optical fiber 201 to the optical time domain reflectometer.

[0049] See also Figure 3 and Figure 4 At this time, the outer diameter φ of the tightly wound optical fiber 201 is known, the outer diameter D of the oil tank outer shell 2 is known, and the distance L from the lead-out point of the optical fiber 201 from the outer shell 2 to the optical time domain reflectometer is known. The position of the leak point can be calculated as (X, Y), where X is the axial distance between the radial plane where the leak point is located and the radial plane of the contact point between the optical fiber 201 and the outer shell 2, and Y is the arc angle of the radial plane where the leak point is located. According to the value of X, the radial plane where the leak point is located can be quickly known, and then the specific position of the leak point on the circumference can be quickly known through Y. The derivation process is:

[0050] The total number of turns of the optical fiber at the location of the leak is [(SL) / (Dπ+2φπ)], that is, the number of turns is obtained by rounding (SL) / (Dπ+φπ);

[0051] Therefore: X=[(SL) / (Dπ+2φπ)]*φ;

[0052] The length of the arc corresponding to the arc angle Y is (SL)-[(SL) / (Dπ+2φπ)]*(Dπ+2φπ);

[0053] Therefore: Y={(SL)-[(SL) / (Dπ+2φπ)]*(Dπ+2φπ)} / (Dπ+2φπ);

[0054] When the detector 104 detects a leakage signal, and the optical signal receiver receives a signal transmission delay or loss between the multiple optical fibers 201, it is apparent that there are leakage points in both the inner shell 1 and the outer shell 2;

[0055] A preparation process of a double-layer oil tank with an online leak detection function is as follows:

[0056] Step 1, the inner shell 1 is prepared and formed;

[0057] Step 2: After the top of the inner shell 1 is opened, the detection tube 102 is inserted, and a reinforcement ring 103 is sleeved on one end of the detection tube 102 located inside the inner shell 1;

[0058] Step 3, weld the bottom of the detection tube 102 to the inner wall of the bottom of the inner shell 1, weld the outer edge of the reinforcement ring 103 to the inner wall of the bottom of the inner shell 1, and weld the inner edge of the reinforcement ring 103 to the outer wall of the detection tube 102; put the guide tube 101 on the end of the top of the detection tube 102 outside the inner shell 1, and the inner diameter of the guide tube 101 is equal to the outer diameter of the detection tube 102, and weld the outer wall of the guide tube 101 to the outer wall of the inner shell 1, and screw a top cover 106 on the top open end of the guide tube 101;

[0059] Step 4: Drill a through hole on the bottom inner wall of the inner shell 1 so that the through hole is connected to the detection tube 102;

[0060] Step 5: Laying an intermediate layer on the outer wall of the inner shell 1;

[0061] Step 6, the bottom glass fiber is wound outside the middle layer, and then the optical fiber 201 is evenly and tightly wound on the bottom glass fiber to form a first detection optical fiber layer, and then the optical fiber 201 is tightly wound again after the first detection optical fiber layer to form a second ranging optical fiber layer, and the second ranging optical fiber layer is only wound on the cylinder, and is not wound at the end, and then the top cover 106 is unscrewed, and the two ends of the optical fiber 201 are led out through the contact point between the wire groove 101.1 of the guide tube 101 and the outer shell 2, and then introduced into the guide tube 101 through the wire groove 101.1 and the threading notch 101.2, and then the top cover 106 is screwed on; then the outer glass fiber is wound on the optical fiber 201 for protection;

[0062] Step 7, unscrew the top cover 106, insert the detector 104 into the detection tube 102, and screw the locking ring 105 provided on the head of the detector 104 into the guide tube 101 and press it on the end surface of the top open end of the detection tube 102;

[0063] Step 8: After the optical fiber 201 introduced into the guide tube 101 and the lead wire of the detector 104 pass through the lead wire hole 106.1 of the top cover 106, the top cover 106 is screwed onto the guide tube 101, and then glass fiber is pasted in the wire groove 101.1 and the threading notch 101.2 for curing and sealing;

[0064] Furthermore, in the winding of the optical fiber 201 in the above step 6, the first layer of the detection optical fiber layer is wound in three sections and then led out, and the three sections are respectively a left-to-multiple spiral winding section, a middle single winding section, and a right-to-multiple winding section; the middle single winding section is the optical fiber 201 that is wound from the contact point to the contact guide tube 101 and then reversely wound to the contact guide tube 101 again, and the reciprocating cycle is repeated until the space between the left-to-multiple spiral winding section and the right-to-multiple winding section is completely wound;

[0065] In addition: It should be noted that the above specific implementation is only an optimization scheme of this patent. Any changes or improvements made by technicians in this field based on the above concept are within the scope of protection of this patent.

Claims

1. A double-layer oil tank preparation process with online leak detection function, Features: Step 1: preparing and molding the inner shell (1); Step 2: After a hole is opened at the top of the inner shell (1), a detection tube (102) is inserted therein, and a reinforcement ring (103) is sleeved onto one end of the detection tube (102) located inside the inner shell (1); Step 3, welding the bottom of the detection tube (102) to the inner wall of the bottom of the inner shell (1), welding the outer edge of the reinforcement ring (103) to the inner wall of the bottom of the inner shell (1), and welding the inner edge of the reinforcement ring (103) to the outer wall of the detection tube (102); sleeve the guide tube (101) on the end of the top of the detection tube (102) outside the inner shell (1), and the inner diameter of the guide tube (101) is equal to the outer diameter of the detection tube (102), and a top cover (106) is screwed onto the top open end of the guide tube (101); Step 4, drilling a through hole on the bottom inner wall of the inner shell (1) so that the through hole is connected to the detection tube (102); Step 5: Laying an intermediate layer on the outer wall of the inner shell (1); Step 6, the bottom glass fiber is wound outside the middle layer, and then the optical fiber (201) is evenly and tightly wound on the bottom glass fiber to form a first detection optical fiber layer, and then the optical fiber (201) is tightly wound again after the first detection optical fiber layer to form a second ranging optical fiber layer, the second ranging optical fiber layer is only wound on the cylinder body, and is not wound at the end, and then the top cover (106) is unscrewed, and the head and tail ends of the optical fiber (201) are led out through the contact point between the wire groove (101.1) of the guide tube (101) and the outer shell (2), and then introduced into the guide tube (101) through the wire groove (101.1) and the wire threading notch (101.2), wherein the wire groove (101.1) is vertically arranged on the lower outer wall of the guide tube (101), and the outer wall of the open end of the guide tube (101) is concave downward to form a wire threading notch (101.2), and the wire threading notch (101.2) is located on the same straight line as the wire groove (101.1); Step 7, insert the detector (104) into the detection tube (102), and screw the locking ring (105) provided on the head of the detector (104) into the guide tube (101) and press it onto the end surface of the top open end of the detection tube (102); Step 8: After the optical fiber (201) introduced into the guide tube (101) and the lead wire of the detector (104) are passed through the lead wire hole (106.1) of the top cover (106), the top cover (106) is screwed onto the guide tube (101), and then glass fiber paste is used to cure and seal the wire groove (101.1) and the wire threading notch (101.2).

2. A double-layer oil tank preparation process with an online leak detection function as claimed in claim 1, Features: In the winding of the optical fiber (201) in the above step 6, the first layer of the detection optical fiber layer is wound in three sections and then led out, and the three sections are a left-facing multiple spiral winding section, a middle single winding section, and a right-facing multiple winding section; the middle single winding section is the optical fiber (201) that is wound from the contact point to the contact guide tube (101) and then reversely wound to the contact guide tube (101) again, and the reciprocating cycle is repeated until the space between the left-facing multiple spiral winding section and the right-facing multiple winding section is completely wound.

Images