Exhaust steam pipe allowing for on-site air tightness / pneumatic testing, and testing method

Abstract

The present application relates to the technical field of condenser pipes, and specifically to an exhaust steam pipe allowing for on-site air tightness / pneumatic testing, and a testing method. The exhaust steam pipe comprises: a main pipe (1), wherein the main pipe (1) comprises a steam inlet end (1a) and a steam outlet end (1b); a bent pipe balance compensator (2), at least comprising a first port (2a) and a second port (2b) which are in communication with each other, wherein the first port (2a) is connected to the steam inlet end (1a) of the main pipe (1); a docking pipe (3), comprising a first pipe (31) and a second pipe (32), wherein a second end (31a) of the first pipe (31) and a second end (32a) of the second pipe (32) are coaxially and detachably connected in a first axis direction; and a gasket (4), detachably interposed between the second end (31a) of the first pipe (31) and the second end (32a) of the second pipe (32), wherein the thickness of the gasket (4) is greater than or equal to the thickness of a blind plate subsequently used for sealing the second end (31a) of the first pipe (31).

Description

Exhaust pipes and testing methods that can be tested for air tightness / pressure on site Technical Field

[0001] This application relates to the field of condenser piping technology, specifically to an exhaust pipe and testing method that can be tested for air tightness / pressure on site. Background Technology

[0002] The exhaust pipe is a pipe that connects the direct air-cooled condenser and the turbine exhaust port. Its main function is to transport the exhaust steam from the turbine to the air-cooled condenser for condensation. The pipe diameter is generally above DN1000 and the length varies from 10m to 30m. It is equipped with pipe accessories such as elbows, tees, expansion joints, and supports.

[0003] Currently, the design pressure of this pipeline is generally 0.1 MPa(g). The pipeline is assembled by welding on site, and after welding, 20% of the circumferential and longitudinal welds are subjected to non-destructive testing. After welding, the entire pipeline, together with the air cooler, undergoes an air tightness test. No leakage is considered a successful pipeline installation and acceptance test. However, with market demand, especially in the European and Russian markets, the design pressure of the entire direct air-cooled condenser system has gradually increased to 0.35 MPa(g). The exhaust pipeline design has entered the category of pressure pipelines, and after on-site assembly, not only is an air tightness test required, but also an on-site pressure test.

[0004] Currently, the exhaust pipe is arranged such that one end connects to the inlet of the air-cooled condenser, and the other end connects to the exhaust port of the steam turbine. Whether for pressure testing or airtightness testing, the exhaust pipe must be temporarily cut off and then sealed from the turbine exhaust port end. Due to structural limitations, the turbine exhaust port often cannot be completely sealed. Therefore, it is generally necessary to cut off a section of the intermediate pipe and weld a temporary blind flange to achieve airtightness or pressure testing. However, this approach has the following drawbacks:

[0005] (1) On-site cutting, welding and removal of blind flanges of pipelines are difficult to carry out and increase additional costs.

[0006] (2) The section of pipeline from the cut-off point to the exhaust port could not be included in the test.

[0007] (3) Temporary shutdown can only be a one-time test. After the unit is overhauled and restarted, a second air tightness or pressure test needs to be performed by shutting down again.

[0008] In light of the above points, on-site airtightness and pressure testing of exhaust pipes is currently difficult to achieve. Therefore, most projects have abandoned on-site testing, resulting in some leaks or on-site welding problems going undetected. This can lead to vacuum leaks during unit operation, affecting normal unit operation. However, with market demands, on-site airtightness and pressure testing are becoming increasingly important and are gradually becoming mandatory requirements. Therefore, the design, improvement, and innovation of exhaust pipes are particularly crucial. Application content

[0009] In order to solve at least one of the technical problems mentioned in the background art, the purpose of this application is to provide a steam exhaust pipe and a testing method that can be tested for air tightness / pressure on site.

[0010] To achieve the above objectives, this application provides the following technical solution:

[0011] On the one hand, this application provides a steam exhaust pipe that can be tested for air tightness / pressure on-site, comprising:

[0012] The main pipeline includes a steam inlet end and a steam outlet end. The steam inlet end is used to connect to the exhaust port of the steam turbine; the steam outlet end is used to connect to the inlet of the condenser.

[0013] The curved pipe balancing compensator includes at least a first port and a second port that are connected; the first port is connected to the steam inlet end of the main pipe.

[0014] The connecting pipeline includes a first pipeline and a second pipeline. The first end of the first pipeline is connected to the second port of the curved pipe balance compensator. The first end of the second pipeline is connected to the exhaust port of the steam turbine. The second ends of the first pipeline and the second ends of the second pipeline are coaxially and detachably connected along the first axis.

[0015] A gasket is detachably placed between the second end of the first pipe and the second end of the second pipe, and the thickness of the gasket is greater than or equal to the thickness of the blind flange subsequently used to seal the second end of the first pipe.

[0016] As an optional embodiment of this application, the second end of the first pipe and the second end of the second pipe are connected by a flange assembly.

[0017] As an optional embodiment of this application, the flange assembly includes a first flange and a second flange that can be coaxially connected by a bolt assembly; the first flange is fixed to the second end of the first pipe, and the second flange is fixed to the second end of the second pipe.

[0018] As an optional embodiment of this application, a sealing gasket is provided between the first flange and the gasket, and / or a sealing gasket is provided between the second flange and the gasket.

[0019] As an optional embodiment of this application, the gasket is provided with one or more lugs on its periphery.

[0020] As an optional implementation of this application, the first axis direction is vertical, and the first pipe is located below the second pipe.

[0021] As an optional embodiment of this application, the exhaust pipe further includes an elastic support member, which is disposed below the curved pipe balance compensator for vertical support of the curved pipe balance compensator.

[0022] As an optional embodiment of this application, the elastic support includes a spring bracket.

[0023] On the other hand, this application also provides a test method for exhaust pipes based on the above-mentioned on-site airtightness / pressure test, including the following steps:

[0024] S1. Disconnect the second ends of the first pipe and the second ends of the second pipe from each other, so that the second ends of the first pipe and the second ends of the second pipe are no longer connected.

[0025] S2. Apply force to move the second end of the first pipe a certain distance away from the second end of the second pipe along the first axis direction, so that the second end of the first pipe and the second end of the second pipe release the clamping of the gasket.

[0026] S3. Apply force to pull out the gasket;

[0027] S4. Provide a blind flange that can be detachably connected to the second end of the first pipe, and after inserting the blind flange between the second end of the first pipe and the second end of the second pipe, connect the blind flange to the second end of the first pipe to seal the second end of the first pipe.

[0028] S5. Test gas is introduced into the exhaust pipe to conduct an airtightness / pressure test.

[0029] As an optional implementation of this application, the above-described test method further includes the following steps:

[0030] S6. After the test is completed in step S5, remove the blind flange; reinstall the gasket between the second end of the first pipe and the second end of the second pipe, and reconnect and fix the second end of the first pipe and the second end of the second pipe.

[0031] Compared with existing technologies, the advantages of this solution are:

[0032] In this scheme, a curved pipe balance compensator, a first pipe and a second pipe are set to connect the main pipe and the condenser inlet, and the second end of the first pipe and the second end of the second pipe are connected along the disassembly point, and a gasket is set at the same time.

[0033] Therefore, when an airtightness / pressure test is required, the connection between the second end of the first pipe and the second end of the second pipe can be disassembled, the gasket can be removed, and the blind flange used to seal the second end of the first pipe can be connected to the second end of the first pipe to seal the second end of the first pipe before proceeding with the subsequent test operation.

[0034] As can be seen, the exhaust pipe provided in this application can be used for on-site air tightness / pressure testing; moreover, it eliminates the need for partial cutting or welding of blind flanges to the entire exhaust pipe for testing, simplifying the operation; and the test can be repeated multiple times.

[0035] It is worth noting that the main function of the gasket is to fill the space between the second ends of the first and second pipes, so that after the gasket is removed, there is sufficient space between the second ends of the first and second pipes for the blind flange to be installed.

[0036] The significance of installing the curved pipe balancing compensator is as follows:

[0037] First, it can absorb the thermal displacement generated by the main pipeline and other components during the operation of the entire turbine-condenser system.

[0038] Secondly, since the gasket is clamped between the second ends of the first and second pipes, the second ends of the first and second pipes exert a large clamping force on the gasket, making it very difficult to remove the gasket from between the second ends of the two pipes later. Therefore, a curved pipe balance compensator is set up because the curved pipe balance compensator itself has a certain degree of freedom of movement. For example, in this application, it has a certain degree of freedom of movement in at least the first axial direction (i.e., vertical), that is, it can move vertically a certain distance. In this way, after the connection between the second ends of the first and second pipes is released, a force can be applied to drive the first pipe to move downward a certain distance, thereby making the first and second pipes relatively far apart, so as to loosen the clamping force on the gasket. Without the clamping force of the two pipes, the gasket can be more easily removed.

[0039] Moreover, in this scheme, the blind flange is sealed at the second end of the first pipe, which is relatively close to the turbine exhaust port, thus allowing as many pipes as possible to participate in the test. Attached Figure Description

[0040] Figure 1 is a schematic diagram of the structure of this application;

[0041] Figure 2 is a partial structural schematic diagram of the connecting pipeline of this application;

[0042] Figure 3 is a schematic diagram of the structure of the gasket in this application;

[0043] Figure 4 is a schematic diagram of the curved pipe balance compensator of this application;

[0044] Figure 5 is a schematic structural view of the curved tube balancing compensator of this application. Detailed Implementation

[0045] The technical solutions of the embodiments of this application will be explained and described below with reference to the accompanying drawings. However, the following embodiments are only preferred embodiments of this application and not all of them. Other embodiments obtained by those skilled in the art based on the embodiments in the implementation methods without creative effort are all within the protection scope of this application.

[0046] In the following description, terms such as “inner,” “outer,” “upper,” “lower,” “left,” and “right” that indicate orientation or positional relationship are used only for the convenience of describing the embodiments and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Example

[0047] Please refer to Figures 1-5. This embodiment provides a steam exhaust pipe that can be tested for air tightness / pressure on site. That is, the steam exhaust pipe provided in this embodiment can be used for both air tightness and pressure tests; in particular, it can be used for on-site air tightness or pressure tests of steam exhaust pipes.

[0048] The exhaust pipe, sometimes also called the main exhaust pipe, is a pipe that connects the direct air-cooled condenser (hereinafter referred to as the condenser) and the turbine exhaust port. Its main function is to transport the exhaust steam from the turbine to the air-cooled condenser for condensation. The pipe diameter is generally above DN1000 and the length varies from 10m to 30m. It is equipped with pipe accessories such as elbows, tees, expansion joints, and supports.

[0049] The air tightness test of the exhaust pipe is mainly used to test the air tightness of the exhaust pipe; while the air pressure test is mainly used to test the compressive strength of the exhaust pipe.

[0050] Additionally, it is worth noting that the field test mentioned above refers to the test conducted under the condition that the turbine, condenser, and exhaust pipe have been assembled. For example, after the entire system has been running for a period of time, an airtightness or pressure test is conducted on the exhaust pipe in the system. This is different from the test conducted before the exhaust pipe is assembled.

[0051] As shown in Figure 1, the exhaust pipe provided in this embodiment mainly includes a main pipe 1, a curved pipe balance compensator 2, a connecting pipe 3, a gasket 4, and elastic support components. The following is a detailed description of each component:

[0052] As shown in Figure 1, the main pipeline 1 includes an inlet end 1a and an outlet end 1b. The inlet end 1a is used to connect to the exhaust port of the steam turbine; the outlet end 1b is used to connect to the inlet of the condenser. During operation, the steam discharged from the exhaust port of the steam turbine enters the main pipeline 1 through the inlet end 1a, and then enters the condenser through the outlet end 1b via the inlet of the condenser.

[0053] It is worth noting that the steam outlet 1b of the main pipeline 1 can be one or more to correspond to multiple condensers. For example, as shown in Figure 1 of this embodiment, the main pipeline 1 has one steam inlet 1a and four steam outlets 1b. Specifically, it mainly includes a main pipe 11 and four branch pipes 12 connected to the main pipe 11. The end of the main pipe 11 away from the branch pipes 12 constitutes the steam inlet 1a of the main pipeline 1, while the end of the branch pipes 12 away from the main pipe 11 constitutes the steam outlet 1b of the main pipeline 1. Thus, the four branch pipes 12 form four steam outlets 1b.

[0054] Understandably, in some embodiments, each steam outlet 1b or branch pipe 12 is equipped with a valve to control the opening / closing of the steam outlet 1b.

[0055] As shown in Figures 1 and 4, the curved pipe balance compensator 2 includes at least a first port 2a and a second port 2b that are connected. The curved pipe balance compensator 2 is similar to a multi-port pipe with multiple ports. Unlike traditional rigid pipes, it has a certain degree of freedom of movement, or deformation capability. Generally speaking, the curved pipe balance compensator 2 can move a distance of about 50mm.

[0056] Curved tube balance compensators are widely used in some condenser-turbine systems, mainly to absorb the thermal displacement generated by the operation of the system pipeline.

[0057] In some embodiments, the curved pipe balance compensator 2 adopts a three-way structure, as shown in Figure 1. It mainly includes three interconnected ports, two of which are located on opposite sides, and the other port is located in the middle of the curved pipe balance compensator 2 and faces upward. In this embodiment, of the three ports, one of the two ports on opposite sides is used as the first port 2a, and the other is blocked by a sealing plate; while the middle port is used as the second port 2b.

[0058] As shown in Figure 4, the first port 2a of the curved pipe balance compensator 2 is connected to the steam inlet 1a of the main pipe 1.

[0059] The connecting pipe 3 is mainly used to connect the exhaust port of the steam turbine and the second port 2b of the curved pipe balance compensator 2.

[0060] Referring to Figures 1 and 2, the connecting pipe 3 includes a first pipe 31 and a second pipe 32; the first end of the first pipe 31 is connected to the second port 2b of the curved pipe balance compensator 2, and the two are coaxially arranged and connected.

[0061] Taking the perspective shown in Figure 1 as an example, the first end of the first pipe 31 can be considered as the lower end of the first pipe 31; the second end of the first pipe 31 can be considered as the upper end of the first pipe 31; the first end of the second pipe 32 can be considered as the upper end of the second pipe 32, and the second end of the second pipe 32 can be considered as the lower end of the second pipe 32.

[0062] Taking the perspective of Figure 2 as an example, the second end of the first pipe 31 is shown as 31a in the figure, and the second end of the second pipe is shown as 32a in the figure.

[0063] The first end of the second pipe 32 is connected to the exhaust port of the steam turbine; the second ends of the first pipe 31 and the second ends of the second pipe 32 are coaxially and detachably connected along the first axis direction; in some embodiments, as shown in Figures 1 and 2, both the first pipe 31 and the second pipe 32 are straight pipe structures, and they are coaxially arranged along the first axis direction. For example, as shown in Figure 1, the main pipe 11 extends laterally, and the curved pipe balance compensator 2 is coaxially connected to the main pipe 11 laterally; wherein the second port 2b of the curved pipe balance compensator 2 is vertically arranged, and the first axis direction can also be understood as vertical, or the axial direction of the second port 2b. In addition, the first pipe 31 is located below the second pipe 32.

[0064] In addition, due to the presence of the curved pipe balance compensator 2, the second end of the first pipe 31 and the second end of the second pipe 32 can move relative to each other along the first axis direction (i.e., vertically) a certain distance when the first pipe 31 and the second pipe 32 are disassembled.

[0065] For example, the second pipe 32 is connected to the exhaust port of the steam turbine and remains stationary; while after the second end of the first pipe 31 is separated from the second end of the second pipe 32, the second end of the first pipe 31 can move downward a certain distance relative to the second end of the second pipe 32 so that the second ends of the first pipe 31 and the second pipe 32 can loosen their clamping on the gasket 4, so as to facilitate the subsequent removal of the gasket 4 and the installation of the blind flange.

[0066] It is worth noting that when conducting airtightness / pressure tests on exhaust pipes, test gas needs to be introduced into the exhaust pipes to create a certain pressure. Therefore, both sides of the exhaust pipes need to be sealed before the test. The side of the exhaust pipe near the condenser inlet can be sealed directly by closing the valve on branch pipe 12; while the exhaust port near the turbine side can be sealed by a blind flange. At this time, the section of the exhaust pipe between the valve and the blind flange is the section of the pipe to be tested.

[0067] In this embodiment, a blind flange (not shown in the figure) is detachably connected to the second end of the first pipe 31 to seal the second end of the first pipe 31. That is, after the gasket 4 is removed, the blind flange is inserted between the second ends of the first pipe 31 and the second pipe 32 and connected to the second end of the first pipe 31 to seal the second end of the first pipe 31.

[0068] The main function of the gasket 4 is to fill the space between the second ends of the first pipe 31 and the second pipe 32, so that after the gasket 4 is removed, there is enough space between the second ends of the first pipe 31 and the second ends of the second pipe 32 for the blind plate to be installed. Therefore, in this embodiment, the thickness of the gasket 4 needs to be greater than or equal to the thickness of the blind plate.

[0069] In other words, assuming that the gasket 4 is not installed and the second ends of the first pipe 31 and the second pipe 32 are directly connected, when a blind flange is needed for sealing, even if the first pipe 31 moves downward a certain distance with the curved pipe balance compensator 2, the distance between the second ends of the first pipe 31 and the second pipe 32 is not enough for the blind flange to be installed. This is mainly because the thickness of the blind flange used is generally more than 50mm, while the floating distance of the curved pipe balance compensator 2 is generally around 50mm. That is to say, the first pipe 31 can only descend by a maximum of about 50mm. Therefore, the maximum distance between the second ends of the first pipe 31 and the second pipe 32 is only 50mm, which is obviously difficult to insert a blind flange with a thickness of more than 50mm.

[0070] Therefore, in this embodiment, a gasket 4 is provided to fill the space between the second ends of the first pipe 31 and the second pipe 32, so that there is a sufficient initial gap between the second ends of the first pipe 31 and the second pipe 32, which is the thickness of the gasket 4; thus, after the gasket 4 is subsequently removed, the gap between the second ends of the first pipe 31 and the second pipe 32 is sufficient for the blind plate to be inserted.

[0071] Therefore, the significance of setting up the curved pipe balance compensator 2 in this embodiment is as follows:

[0072] First, it can absorb the thermal displacement generated by the main pipeline 1 during the operation of the entire turbine-condenser system.

[0073] Secondly, since the gasket 4 is clamped between the second ends of the first pipe 31 and the second pipe 32, the second ends of the first pipe 31 and the second pipe 32 will exert a large clamping force on the gasket 4. Therefore, it is very difficult to remove the gasket 4 from between the second ends of the two pipes later. Therefore, a curved pipe balance compensator 2 is set. Because the curved pipe balance compensator 2 has a certain degree of freedom of movement, for example, in this application, it has at least a certain degree of freedom of movement in the vertical direction, that is, it can move vertically a certain distance. In this way, after the connection between the second ends of the first pipe 31 and the second pipe 32 is released, force can be applied to drive the first pipe 31 to move downward a certain distance, so that the first pipe 31 and the second pipe 32 are relatively far apart, so as to loosen the clamping force on the gasket 4. Without the clamping force of the two pipes, the gasket 4 can be pulled out more easily.

[0074] Furthermore, in this embodiment, the blind flange is sealed at the second end of the first pipe 31, which is relatively close to the turbine exhaust port. This allows as much of the exhaust pipe as possible to participate in the test. In other words, the shorter the second pipe 32, the closer the sealing point (i.e., the blind flange sealing position) of the entire exhaust pipe is to the turbine exhaust port, and thus the longer the exhaust pipe travels in the test.

[0075] In some embodiments, when performing blind flange sealing, the blind flange is also connected to the second end of the first pipe 31 in a detachable manner.

[0076] In some embodiments, the second end of the first pipe 31 and the second end of the second pipe 32 can be detachably connected to each other via the flange assembly 5. Specifically:

[0077] As shown in Figure 2, the flange assembly 5 includes a first flange 51 and a second flange 52 that can be coaxially connected by a bolt assembly (not shown in the figure); the first flange 51 is fixed to the second end of the first pipe 31, and the second flange 52 is fixed to the second end of the second pipe 32.

[0078] In some embodiments, the bolt assembly includes bolts and nuts adapted to the bolts; during connection, the first flange 51 and the second flange 52 are aligned with each other, and then the bolts are passed through the flange holes on the two flanges in sequence and the nuts are tightened to achieve the flange connection.

[0079] Of course, in some other alternative implementations, the bolt assembly may consist of only bolts, with one flange having a flange hole designed to fit the bolts as threaded holes, and the other flange having a through hole. In this way, after the two flanges are aligned, the bolts pass through the bolt holes and are threaded into the threaded holes to lock the two flanges. This method can also achieve the connection of the two flanges.

[0080] When it is necessary to disassemble the first pipe 31 and the second pipe 32, remove the bolt assembly and disconnect the connection between the two first flanges 51 and the second flange 52. At this time, force can be applied to drive the second ends of the first pipe 31 and the second pipe 32 away from each other to loosen the clamping on the gasket 4.

[0081] In some embodiments, the connection between the blind flange and the first pipe 31 can also adopt a structure similar to that of a flange connection, that is, a flange hole is also opened on the blind flange at the position corresponding to the flange hole of the first flange 51. In this way, the blind flange and the first flange 51 can also be connected in a manner similar to that of a flange connection using bolt assemblies to seal the second end of the first pipe 31.

[0082] To facilitate the subsequent removal of the gasket 4 from between the first flange 51 and the second flange 52, one or more lifting lugs 41 are provided around the gasket 4. The lifting lugs 41 serve as the force points for the subsequent removal of the flange, and the gasket 4 is pulled out by connecting the lifting lugs 41 through mechanical equipment.

[0083] To improve the sealing between the flange and the gasket 4, a sealing gasket 53 is provided between the first flange 51 and the gasket 4, and / or a sealing gasket 53 is provided between the second flange 52 and the gasket 4.

[0084] In addition, the gasket 4 can be connected to the first flange 51 using the aforementioned bolt assembly connection method, that is, a hole for bolt assembly connection is also opened at the flange hole position of the gasket 4 corresponding to the first flange 51.

[0085] In order to support the curved pipe balance compensator 2, in this embodiment, the exhaust pipe also includes an elastic support member. The elastic support member is located below the curved pipe balance compensator 2 for vertical support of the curved pipe balance compensator 2. In specific installation, elastic support members are set on both sides of the bottom of the curved pipe balance compensator 2.

[0086] The elastic support can be an existing spring bracket 6, which mainly includes a base and a shaft that can extend and retract vertically relative to the base. A spring is provided between the base and the shaft, and the spring provides elastic force to drive the shaft to have an upward lifting tendency. This type of spring bracket 6 has been described and applied extensively in the prior art, and will not be elaborated on here. In addition, some existing spring brackets 6 are usually equipped with a locking device, such as a screw, which can lock the shaft at any extension height to keep the shaft and the base relatively fixed.

[0087] The advantage of using this lockable spring bracket 6 is that after the first pipe 31 and the second pipe 32 are separated, during the downward movement of the first pipe 31, the elastic force of the spring bracket 6 will be overcome to push the shaft downward. When the shaft moves to the set position, the locking member locks the shaft. At this time, the shaft will not be pushed upward under the action of the spring, ensuring that the second ends of the first pipe 31 and the second pipe 32 are kept apart. Example

[0088] This embodiment provides a test method for an exhaust pipe that can be tested on-site for air tightness / pressure, based on Embodiment 1. The specific structure of the exhaust pipe is described in detail in Embodiment 1, so it will not be repeated here. The test method mainly includes the following steps:

[0089] S1. Disconnect the second end of the first pipe 31 and the second end of the second pipe 32 from each other, so that the second end of the first pipe 31 and the second end of the second pipe 32 are disconnected.

[0090] Taking the second end of the first pipe 31 and the second end of the second pipe 32 as an example, the connection can be released by removing the bolt assembly during disassembly.

[0091] S2. Apply force to move the second end of the first pipe 31 a certain distance away from the second end of the second pipe 32 along the first axis direction, so that the second end of the first pipe 31 and the second end of the second pipe 32 release the clamping of the gasket 4.

[0092] For example, mechanical equipment (such as hydraulic equipment) is used to press down the spring bracket 6 and / or the curved pipe balance compensator 2 and / or the first pipe 31, so that the first pipe 31 moves down a certain distance, thereby releasing the clamping of the gasket 4 by the second end of the first pipe 31 and the second end of the second pipe 32. Then, the spring bracket 6 is locked.

[0093] S3. Apply force to pull out the gasket. This can be done using mechanical equipment with the lifting lugs on the gasket.

[0094] S4. Provide a blind flange that can be detachably connected to the second end of the first pipe 31, and insert the blind flange into the gap space to connect it to the second end of the first pipe 31 to seal the second end of the first pipe 31; wherein the blind flange is also connected to the second end of the first pipe 31 using a bolt assembly. And close the valve on the side of the exhaust pipe near the condenser inlet. At this time, the exhaust pipe forms a closed pipe section between the blind flange and the valve, which will participate in subsequent tests.

[0095] S5. Test gas is introduced into the exhaust pipe to conduct an airtightness / pressure test.

[0096] One way to introduce the test gas is to leave a reserved port on the exhaust pipe for the test gas to enter; or to use some built-in ports on the exhaust pipe (such as the drain port of the exhaust pipe) as channels for gas to enter; in this way, the gas is filled into the exhaust pipe.

[0097] When conducting an airtightness test, the main focus is on checking whether there are any leaks in the exhaust pipe.

[0098] The main purpose of the air pressure test is to check the pressure resistance of the exhaust pipe.

[0099] Using gas to conduct air pressure or airtightness tests on pipelines has many existing implementation methods, which will not be specifically limited here.

[0100] Finally, after the test is completed in step S5, remove the blind plate; reinstall the gasket 4 between the second end of the first pipe 31 and the second end of the second pipe 32, and reconnect and fix the second end of the first pipe 31 and the second end of the second pipe 32.

[0101] It will be apparent to those skilled in the art that this application is not limited to the details of the exemplary embodiments described above, and that this application can be implemented in other specific forms without departing from the spirit or essential characteristics of this application. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of this application is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this application.

Claims

1. A steam exhaust pipe capable of on-site airtightness / pressure testing, characterized in that, include: The main pipeline includes a steam inlet end and a steam outlet end. The steam inlet end is used to connect to the exhaust port of the steam turbine; the steam outlet end is used to connect to the inlet of the condenser. The curved pipe balancing compensator includes at least a first port and a second port that are connected; the first port is connected to the steam inlet end of the main pipe. The connecting pipeline includes a first pipeline and a second pipeline. The first end of the first pipeline is connected to the second port of the curved pipe balance compensator. The first end of the second pipeline is connected to the exhaust port of the steam turbine. The second ends of the first pipeline and the second ends of the second pipeline are coaxially and detachably connected along the first axis. A gasket is detachably placed between the second end of the first pipe and the second end of the second pipe, and the thickness of the gasket is greater than or equal to the thickness of the blind flange subsequently used to seal the second end of the first pipe.

2. The exhaust pipe capable of on-site airtightness / pressure testing according to claim 1, characterized in that, The second end of the first pipe and the second end of the second pipe are connected by a flange assembly.

3. The exhaust pipe capable of on-site airtightness / pressure testing according to claim 1, characterized in that, The flange assembly includes a first flange and a second flange that can be coaxially connected via a bolt assembly; the first flange is fixed to the second end of the first pipe, and the second flange is fixed to the second end of the second pipe.

4. The exhaust pipe capable of on-site airtightness / pressure testing according to claim 3, characterized in that, A sealing gasket is provided between the first flange and the gasket, and / or a sealing gasket is provided between the second flange and the gasket.

5. The exhaust pipe capable of on-site airtightness / pressure testing according to claim 1, characterized in that, The gasket has one or more lugs around its periphery.

6. The exhaust pipe capable of on-site airtightness / pressure testing according to claim 1, characterized in that, The first axis is vertical, and the first pipe is located below the second pipe.

7. The exhaust pipe capable of on-site airtightness / pressure testing according to claim 1, characterized in that, The exhaust pipe also includes an elastic support component, which is located below the curved pipe balance compensator for vertical support of the curved pipe balance compensator.

8. The exhaust pipe capable of on-site airtightness / pressure testing according to claim 7, characterized in that, The elastic support includes a spring bracket.

9. A test method for exhaust pipes capable of on-site airtightness / pressure testing as described in any one of claims 1-8, characterized in that, Includes the following steps: S1. Disconnect the second ends of the first pipe and the second ends of the second pipe from each other, so that the second ends of the first pipe and the second ends of the second pipe are no longer connected. S2. Apply force to move the second end of the first pipe a certain distance away from the second end of the second pipe along the first axis direction, so that the second end of the first pipe and the second end of the second pipe release the clamping of the gasket. S3. Apply force to pull out the gasket; S4. Provide a blind flange that can be detachably connected to the second end of the first pipe, and after inserting the blind flange between the second end of the first pipe and the second end of the second pipe, connect the blind flange to the second end of the first pipe to seal the second end of the first pipe. S5. Test gas is introduced into the exhaust pipe to conduct an airtightness / pressure test.

10. The test method according to claim 9, characterized in that, It also includes the following steps: S6. After the test is completed in step S5, remove the blind flange; reinstall the gasket between the second end of the first pipe and the second end of the second pipe, and reconnect and fix the second end of the first pipe and the second end of the second pipe.

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