WO-2026091214-A1 - EXHAUST STEAM PIPE ALLOWING FOR ON-SITE AIR TIGHTNESS/PNEUMATIC TESTING, AND TESTING METHOD

WO2026091214A1WO 2026091214 A1WO2026091214 A1WO 2026091214A1WO-2026091214-A1

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).

Inventors

WANG, JING
WANG, Zhanchi
HU, YI
DU, Hongyu
FENG, Yixiong
HU, Bingtao
LIU, YUJUN
JIANG, Cihai

Assignees

杭州国能汽轮工程有限公司

Dates

Publication Date: 20260507
Application Date: 20241127
Priority Date: 20241104

Claims (10)

A steam exhaust pipe capable of on-site airtightness/pressure testing is characterized by comprising: 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.
According to claim 1, the exhaust pipe capable of on-site airtightness/pressure testing is characterized in that the second end of the first pipe and the second end of the second pipe are connected by a flange assembly.
According to claim 1, the exhaust pipe capable of on-site airtightness/pressure testing is characterized in that 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.
The exhaust pipe capable of on-site airtightness/pressure testing according to claim 3 is 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.
According to claim 1, the exhaust pipe capable of on-site airtightness/pressure testing is characterized in that one or more lifting lugs are provided around the gasket.
The exhaust pipe capable of on-site airtightness/pressure testing according to claim 1 is characterized in that the first axial direction is vertical, and the first pipe is located below the second pipe.
According to claim 1, the exhaust pipe capable of on-site airtightness/pressure testing is characterized in that 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.
According to claim 7, the exhaust pipe capable of on-site airtightness/pressure testing is characterized in that the elastic support includes a spring bracket.
The test method for exhaust pipes capable of on-site airtightness/pressure testing as described in any one of claims 1-8 is characterized by comprising 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.
The test method according to claim 9 is characterized in that it further 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.

Description

Exhaust pipes and testing methods that can be tested for air tightness/pressure on site Technical Field 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 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. 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. 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: (1) On-site cutting, welding and removal of blind flanges of pipelines are difficult to carry out and increase additional costs. (2) The section of pipeline from the cut-off point to the exhaust port could not be included in the test. (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. 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 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. To achieve the above objectives, this application provides the following technical solution: On the one hand, this application provides a steam exhaust pipe that can be tested for air tightness/pressure on-site, comprising: 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. 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. 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