CN217153847U - External pressure type expansion joint with leakage monitoring function - Google Patents

Abstract

The utility model provides an outer die mould expansion joint with leakage monitoring function, including outer die mould expansion joint and leakage monitoring device, leakage monitoring device includes outside leak detection subassembly and middle part determine module, outside leak detection subassembly comprises attached liquid detector one and the sensor that sets up outside die mould expansion joint on outer die mould expansion joint bellows inlayer pipe inner wall, liquid detector one passing signal line is connected with sensor one, middle part determine module comprises liquid detector two and the sensor two that set up outside die mould expansion joint, liquid detector two sets up between the inlayer and the time inlayer pipe of outer die mould expansion joint bellows, liquid detector two passing signal lines are connected with sensor two. The corrosion rate of the corrugated pipe can be indirectly measured, economic loss caused by sudden failure accidents to a user is avoided, the long-period operation reliability and the functional value of the corrugated pipe are improved, and the long-period safe operation of a system pipe network is guaranteed.

Description

External pressure type expansion joint with leakage monitoring function

Technical Field

The utility model relates to an expansion joint technical field, what specifically say so is an outer die mould expansion joint with leakage monitoring function.

Background

According to statistics: corrosion is the primary cause of failure damage to bellows expansion joints, accounting for approximately 80% of the total failure types. Because the expansion joint in high-temperature, high-pressure and corrosive environment is mostly made of iron-nickel-based alloy and high-nickel alloy, corrosion damages such as pitting corrosion, stress corrosion, high-temperature oxidation and the like are mainly used, and the corrosion crack initiation positions are concentrated at the wave crest of the easy effusion, so that the expansion joint has the advantages of paroxysmal property and great harm.

At present, expansion joints applied in the fields of petrochemical industry and coal chemical industry are generally in an internal pressure type, a negative pressure gauge and a pre-vacuumizing are arranged between corrugated pipe layers by adopting the concept of single-layer pressure bearing and double-layer design, and the leakage condition of inner and outer pipe blanks of the corrugated pipe can be indicated according to the change of pressure indication numbers in actual operation. In the field of urban central heating, the expansion joint is generally in an external pressure type because the heating pipe network is located in the soil. In the actual operation process, the corrugated pipe of the external pressure type expansion joint is extremely easy to be corroded and damaged by external corrosive liquid, and certain uncertainty is added to the safe operation of the heat supply pipe network.

The leakage monitoring system of the buried heat supply pipe network has been widely applied in Europe for a long time, in recent years, with the promulgation of CJ/T254-2016 technical Specification for leakage monitoring system of urban heat supply direct-buried hot water pipeline, the impedance or resistance type leakage monitoring technology, the distributed optical fiber leakage monitoring technology, the temperature capsule monitoring technology and the negative pressure wave leakage monitoring technology in China are all applied or tested in corresponding thermal engineering, and the display measurement result has certain reliability. However, the above techniques are based on that the pipeline is damaged, the internal medium enters the environment around the pipeline and is deployed, and are not suitable for monitoring the corrosion leakage of the expansion joint.

"quantitative detection device for leakage of external pressure expansion joint" (patent No. CN 106287237A) provides a method for judging whether external pressure expansion joint leaks or not by adopting a liquid sensor and liquid collecting tanks with different heights. "a totally-enclosed bypass external pressure balanced expansion joint capable of on-line detection" (patent number: CN 208169794U) provides a structure and a method capable of monitoring leakage of a bypass external pressure balanced expansion joint working corrugated pipe and a balanced corrugated pipe. "a double-layer metal expansion joint online leakage monitoring device and method" (patent number: CN 110345330A) provides a double-layer metal expansion joint online leakage monitoring device and method, which can realize online monitoring of damage of any single layer of the double-layer metal expansion joint. 'a heat supply pipeline expansion joint state monitoring device based on a distributed optical fiber temperature sensing system and a method thereof' (patent number: CN 108896203A) provides a heat supply pipeline expansion joint state monitoring device based on a distributed optical fiber temperature sensing system and a method thereof. The prior art or the product does not relate to the early warning function of leakage.

SUMMERY OF THE UTILITY MODEL

For solving the technical problem, the utility model provides an outer die mould expansion joint with leakage monitoring function can indirectly calculate bellows corrosion rate, avoids the proruption failure accident to cause economic loss for the use unit, promotes the long period operational reliability and the functional value of bellows to in time guide the use unit according to corroding the feedback result, actively take corresponding solution, the long period safe operation of guarantee system pipe network.

In order to realize the technical purpose, the adopted technical scheme is as follows: the utility model provides an outer die mould expansion joint with leakage monitoring function, including outer die mould expansion joint and leakage monitoring device, leakage monitoring device sets up the lowest department at outer die mould expansion joint bellows inlayer pipe, leakage monitoring device includes outside leak detection subassembly and middle part detection module, outside leak detection subassembly comprises attached liquid detector one and the sensor that sets up outside die mould expansion joint on outer die mould expansion joint bellows inlayer pipe inner wall, liquid detector one passes through the signal line and is connected with sensor one, middle part detection module comprises liquid detector two and the sensor two that set up outside die mould expansion joint, liquid detector two sets up between the inlayer and the inferior inlayer pipe of outer die mould expansion joint bellows, liquid detector two passes through the signal line and is connected with sensor two.

The first liquid detector is a monitoring line, the first sensor is a resistance sensor, and small holes are machined in the surface of the contact position of the monitoring line and the wave crest of the inner wall of the innermost pipe blank of the corrugated pipe.

The second liquid detector is a sacrificial anode sheet, the sacrificial anode sheet is insulated with the innermost layer and the secondary inner layer tube blank of the corrugated tube, and the second sensor is a current sensor.

The first liquid detector is fixed by water absorption materials.

The coverage range of the sacrificial anode sheet is within 60 degrees of the bottom of the expansion joint.

The utility model has the advantages that: the utility model discloses an outer die mould expansion joint with corrosion monitoring function can be applied to and bury ground, the trench, the heat supply pipe network that forms such as piping lane laid and other similar application occasions, it has certain corrosivity to be particularly suitable for outside hydrops, gather the occasion that easily leads to the pipe to leak at the bellows crest, can promote expansion joint own security and reliability of being on active service effectively, and when producing the property obvious change that appears, send the early warning to the user before leaking, avoid the accident to cause emergency stop.

Drawings

Fig. 1 is a schematic structural view of the leakage monitoring device of the present invention;

FIG. 2 is a schematic structural view of the present invention;

fig. 3 is a schematic structural view of the outlet end ring and the butt joint pipe of the present invention.

In the figure: 1. the device comprises a limiting ring, 2, a corrugated pipe, 3, a monitoring line, 4, a water absorbing material, 5, a sacrificial anode sheet, 6, a butt joint pipe, 7, a communicating pipe, 8, a signal line, 9, a data acquisition controller, 10, an inlet end pipe, 11, a guide cylinder, 12, an outer pipe, 13, an outlet pipe, 6-1, a communicating pipe penetrating hole, 6-2, an anode sheet communicating hole, 6-3 and a leading-out wire communicating hole.

Detailed Description

As shown in fig. 1 and 2, the external pressure type expansion joint with the leakage monitoring function comprises an external pressure type expansion joint and a leakage monitoring device, wherein the external pressure type expansion joint comprises an inlet end pipe 10, a guide cylinder 11, a corrugated pipe 2, an outer pipe 12, an outlet pipe 13, an outlet end ring 14, an end pipe 6 and a limiting ring 1.

The leakage monitoring device is arranged at the lowest part of the innermost pipe blank of the external pressure expansion joint corrugated pipe and comprises an outer side leakage detection assembly and a middle detection assembly; the leakage monitoring device is also suitable for the condition that two groups of corrugated pipes and three groups of corrugated pipes are connected in series.

The outer side leakage detection assembly is composed of a first liquid detector attached to the innermost inner wall of the outer compression expansion joint corrugated pipe and a first sensor arranged outside the outer compression expansion joint, and the outer side leakage detection assembly can be used for early warning and judging whether corrosion effusion exists at the wave crest position of the corrugated pipe or not. The first liquid detector is connected with the first sensor through a signal line, the first liquid detector is arranged on the non-medium contact side of the bottom of the corrugated pipe and is a monitoring line 3, the first sensor is a resistance sensor, and small holes are machined in the surface of the contact part of the monitoring line 3 and the wave crest of the inner wall of the innermost pipe blank of the corrugated pipe. When no liquid exists, the monitoring wire 3 is insulated from the metal cylinder of the expansion joint; once liquid is accumulated, the resistance between the monitoring line and the metal cylinder of the expansion joint is reduced; and applying power excitation between the leading-out end of the monitoring wire and the exposed metal through the data acquisition controller, and judging whether the accumulated liquid exists or not according to the magnitude of the feedback current.

The middle detection assembly is used for monitoring whether the innermost pipe blank of the corrugated pipe is corroded and penetrated, the middle detection assembly consists of a second liquid detector and a second sensor arranged outside the outer pressure expansion joint, the second liquid detector is arranged between the innermost layer of the outer pressure expansion joint corrugated pipe and the second inner layer pipe blank, and the second liquid detector is connected with the second sensor through a signal line. The second liquid detector is a sacrificial anode sheet 5, the sacrificial anode sheet 5 is insulated from the innermost and secondary inner layer tube blanks of the corrugated tube, and the second sensor is a current sensor. By utilizing the difference of the electrode potential difference between the built-in anode sheet 5 and the corrugated pipe 2, when the accumulated liquid conductive liquid exists, a current loop is formed, and the built-in anode sheet 5 with lower potential is corroded and also generates corrosion current. And obtaining the information whether the first layer of tube blank is damaged or not by monitoring whether the current signal is fed back or not.

Through outside leakage detection subassembly and middle part detection subassembly, the corruption severity of corroding the hydrops is inferred indirectly to the time difference that first layer pipe run through from corroding the hydrops existence.

The device with the functions of the resistance sensor and the current sensor is a data acquisition controller 9, can acquire resistance signals and current signals, and has the functions of displaying and alarming. After receiving the resistance and current signals, the data acquisition controller 9 can be connected with a peripheral signal acquisition system, process and transmit the signals, and feed the monitored signal change conditions back to the user side in time, so that the user can know the intact condition of the product in time, and make the best early warning treatment measures.

As shown in fig. 3, a monitoring wire leading-out hole and an embedded part hole are processed on the end joint pipe connected with the corrugated pipe, and a connecting channel of a corrugated pipe monitoring element and an external sensor is established; but also can meet the strength requirement and the manufacturing requirement of each component of the product. In order to facilitate the leading-out of the signal wire, a communicating pipe penetrating hole 6-1, an anode sheet communicating hole 6-2 and a leading-out wire communicating hole 6-3 are processed on the end connecting pipe 6. The monitoring line 3 and the sacrificial anode sheet 5 are respectively connected with the signal line 8 and are connected with the data acquisition controller 9 through a channel which is arranged on an outlet end ring and an outlet wire communication hole 6-3 on a butt joint pipe, an anode sheet communication hole 6-2 and a communicating pipe through hole 6-1. To protect the signal wires, the signal wires may be placed in a communication tube 7 secured to the outlet end ring 14 and the end-connected tube 6.

The first liquid detector is fixed by a water absorption material 4, and the water absorption material 4 can be polyurethane foam or water absorption fiber and the like.

The coverage range of the sacrificial anode sheet is within 60 degrees of the bottom of the expansion joint, and the monitoring can be better carried out within the range.

The structure and the method capable of monitoring the corrosion on line can effectively improve the service safety and reliability of the external pressure type expansion joint, timely send out early warning to a using unit when the product performance is obviously changed, avoid the emergency shutdown of the whole device piping system caused by sudden corrosion damage and reduce the economic loss of the using unit.

The utility model discloses an expansion joint structure and monitoring method function is reliable, compact structure, and the method can reference the nature by reference strong, easily extension.

Claims (5)

1. The utility model provides an outer die mould expansion joint with leak detection function which characterized in that: including external pressure type expansion joint and leakage monitoring device, leakage monitoring device sets up the lowest of the most inboard pipe of external pressure type expansion joint bellows, leakage monitoring device includes outside leak detection subassembly and middle part determine module, outside leak detection subassembly comprises attached liquid detector one and the sensor that sets up outside external pressure type expansion joint on the most inboard pipe inner wall of external pressure type expansion joint bellows, liquid detector one passing signal line is connected with sensor one, middle part determine module comprises liquid detector two and the sensor two that set up outside external pressure type expansion joint, liquid detector two sets up outside external pressure type expansion joint bellows between the inlayer and inferior inlayer, liquid detector two passing signal line is connected with sensor two.

2. An externally profiled expansion joint with leak monitoring as claimed in claim 1 wherein: the first liquid detector is a monitoring line (3), the first sensor is a resistance sensor, and small holes are machined in the surface of the contact part of the monitoring line (3) and the wave crest of the inner wall of the innermost corrugated pipe.

3. An externally profiled expansion joint with leak monitoring as claimed in claim 1 wherein: the second liquid detector is a sacrificial anode sheet (5), the sacrificial anode sheet (5) is insulated from the innermost layer and the secondary inner layer of the corrugated pipe, and the second sensor is a current sensor.

4. An externally profiled expansion joint with leak monitoring as claimed in claim 1 or 2 wherein: the first liquid detector is fixed by a water absorption material (4).

5. An externally profiled expansion joint with leak monitoring as claimed in claim 3 wherein: the coverage range of the sacrificial anode sheet is within 60 degrees of the bottom of the expansion joint.

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