A condenser online leak detection device and method based on condenser vacuum detection

Abstract

The present invention discloses an online condenser leak detection device and method based on condenser vacuum detection. The device comprises a cooling water level measurement and control system, a condenser vacuum measurement system, an air compressor and compressed air delivery system, and a data collection and analysis system. The cooling water level measurement and control system includes a level gauge, a cooling water inlet chamber drain valve, and a cooling water outlet chamber drain valve installed on the condenser. The condenser vacuum measurement system includes a vacuum pressure gauge and a pressure transmitter, which are sequentially connected. The air compressor and compressed air delivery system includes an inlet air compressor. The data collection and analysis system includes a condenser leak heat exchange tube locating module, and the pressure transmitter and inlet air compressor are both electrically connected to the condenser leak heat exchange tube locating module. The present invention can be used in conjunction with existing condenser leak detection devices to further narrow the scope of leak detection.

Description

Technical Field

[0001] The present invention relates to the field of online detection, and in particular to a condenser online leakage detection device and method based on condenser vacuum degree detection. Background Art

[0002] The condenser is a critical cooling device in a power plant, and its operating status directly impacts the safe and economical operation of the entire unit. Cooling water with a high salt content flows through the condenser's heat exchange tubes, while pure steam, nearly free of impurities, flows outside the tubes. If a leak develops in the condenser's heat exchange tubes during operation, the high-salt cooling water leaks into the pure condensate, rapidly contaminating it and deteriorating the unit's steam quality, especially in seawater-cooled power plants. Therefore, condensers are equipped with heat exchange tube leak detection devices during the construction phase. However, existing leak detection devices can only diagnose which water chamber has a leak, not the specific heat exchange tube bank, and cannot analyze and detect leaks.

[0003] Condenser leak detection is a preliminary, rough inspection. A typical condenser has four water chambers, and the condenser leak detection device can only determine which water chamber is leaking, narrowing the search range to 1 / 4. However, it cannot determine which tubes within that water chamber are leaking. For a 600MW unit, each water chamber has approximately 10,000 heat exchange tubes. Maintenance personnel must conduct detailed inspections of each heat exchange tube using methods such as film coating, foam testing, candle flame testing, and helium mass spectrometry to determine which tubes are leaking. This is a massive, time-consuming, and labor-intensive task. Furthermore, leak detection is performed while half of the condenser is operating, creating a confined space with high temperature and high humidity. The conditions are extremely harsh, posing a significant safety hazard to personnel.

[0004] Therefore, if the leaking heat exchange tube can be accurately located and the leak detection range can be further narrowed, it will not only shorten the leak detection time and minimize or reduce the harm of cooling water leakage to the unit, but also greatly reduce the workload of maintenance personnel and reduce safety risks.

[0005] For a typical 600MW unit, each condenser water chamber has approximately 174 rows of heat exchange tubes, with an average of 60 tubes per row, and each row is 2.5cm high. If the positioning accuracy is 5cm, the leak detection range can be narrowed to two rows, reducing the detection workload by 1 / 87. If the positioning accuracy is less than 2.5cm, the range is reduced to one row, reducing the detection workload by 1 / 174. This is of great significance for leak detection. Summary of the Invention

[0006] The present invention aims to provide an online condenser leak detection device and method based on condenser vacuum detection, which can be used in conjunction with an existing condenser leak detection device to further narrow the leak detection range.

[0007] In order to achieve the above objectives, the present invention provides the following technical solutions.

[0008] A condenser online leak detection device based on condenser vacuum detection, including a cooling water level measurement and control system, a condenser vacuum measurement system, an air compressor and compressed air delivery system, and a data collection and analysis system;

[0009] The cooling water level measurement and control system includes a liquid level gauge, a cooling water inlet chamber drain valve, and a cooling water outlet chamber drain valve arranged on the condenser;

[0010] The condenser vacuum degree measurement system includes a vacuum pressure gauge and a pressure transmitter; the vacuum pressure gauge and the pressure transmitter are connected in sequence to obtain the vacuum degree inside the condenser;

[0011] The air compressor and compressed air delivery system includes an air inlet compressor; the air inlet compressor is used to pump oxygen into the cooling water inlet chamber of the condenser;

[0012] The data collection and analysis system includes a condenser leakage heat exchange tube positioning module, and the pressure transmitter and the air inlet compressor are both electrically connected to the condenser leakage heat exchange tube positioning module.

[0013] As a further improvement of the present invention, the condenser vacuum degree measurement system further includes a sampling valve; the sampling valve, vacuum pressure gauge and pressure transmitter are arranged in sequence, and the sampling valve is arranged close to the condenser.

[0014] As a further improvement of the present invention, the air compressor and compressed air delivery system also include an air intake electric valve, a flow meter and a pressure gauge; the air intake electric valve, the flow meter, the pressure gauge and the air compressor are connected in sequence, and the air intake electric valve is connected to the cooling water inlet chamber of the condenser; the air intake electric valve, the flow meter and the pressure gauge are all electrically connected to the condenser leakage heat exchange tube positioning module.

[0015] As a further improvement of the present invention, the air compressor and compressed air delivery system further include a pressure reducing valve and a safety valve; the air compressor, safety valve, pressure reducing valve and pressure gauge are connected in sequence.

[0016] As a further improvement of the present invention, the liquid level meter adopts at least one of a cooling water inlet chamber liquid level meter and a cooling water outlet chamber liquid level meter.

[0017] As a further improvement of the present invention, the "0" level line of the liquid level gauge is based on the bottom plate of the water chamber, the highest water level is not lower than the height of the top row of heat exchange tubes of the condenser, and the display accuracy is not less than 1 cm.

[0018] A method for online leak detection of a condenser based on condenser vacuum detection comprises the following steps:

[0019] When a condenser leaks, after locating the water chamber where the leaking heat exchange tube is located, the unit load is reduced, and the condenser leaking heat exchange tube positioning module adjusts the opening of the cooling water inlet chamber drain valve and the cooling water outlet chamber drain valve, isolating and draining half of the condenser;

[0020] Start the air compressor and compressed air delivery system. The air compressor starts running and the opening of the pressure reducing valve is adjusted to continuously deliver compressed air to the cooling water inlet chamber of the condenser.

[0021] Open the sampling valve of the condenser vacuum measurement system, and the condenser leakage heat exchange tube positioning module collects the pressure data of the condenser vacuum measurement system pressure transmitter in real time; determine the leakage pipe row position through the correspondence between the condenser vacuum pressure change and the water discharge level.

[0022] As a further improvement of the present invention, the air compressor and the compressed air delivery system are started and the pressure is adjusted to 0.3-0.6 MPa and the opening is adjusted to 200-400 ml / min.

[0023] As a further improvement of the present invention, when adjusting the opening of the cooling water inlet chamber drain valve and the cooling water outlet chamber drain valve, the cooling water chamber water level drop speed is controlled to be 10 to 30 mm / min.

[0024] As a further improvement of the present invention, the condenser leaking heat exchange tube positioning module provides a time-condenser vacuum-drain level dual-axis curve in real time.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The present invention includes a condenser leaking heat exchange tube positioning module through the data collection and analysis system, and the pressure transmitter and the air inlet compressor are both electrically connected to the condenser leaking heat exchange tube positioning module. The vacuum pressure gauge and pressure transmitter obtain the internal vacuum degree of the condenser; the air inlet compressor pumps oxygen to the cooling water inlet chamber of the condenser; the leaking heat exchange tube can be located without the maintenance personnel entering the condenser water chamber, which greatly reduces the workload of leak detection, reduces the workload of maintenance personnel, improves work efficiency, and reduces safety risks; the present invention saves leak detection time through online real-time detection. All current methods for locating leaking heat exchange tubes in condensers require maintenance personnel to enter the water chamber to check for leaks after draining the cooling water in the water chamber. However, this method can narrow the location of the leaking heat exchange tube to a certain row or several rows during the draining process, which greatly reduces the workload of maintenance personnel entering the water chamber to check for leaks and saves a lot of leak detection time.

[0027] The positioning method of the present invention fully utilizes the leak detection device and condenser vacuum measurement system provided with the condenser. Only a cooling water level control system, an air compressor and compressed air delivery system, and a data collection and analysis system need to be added to realize the positioning of the leaking heat exchange tube of the condenser, which is easy to implement. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings described herein are for illustrative purposes only and are not intended to limit the scope of the present invention in any way. In addition, the shapes and proportional dimensions of the components in the drawings are only schematic and are used to help understand the present invention, and are not intended to specifically limit the shapes and proportional dimensions of the components of the present invention. In the drawings:

[0029] Figure 1 The present invention is a schematic diagram of an online condenser leak detection device and method based on condenser vacuum detection. DETAILED DESCRIPTION

[0030] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0031] It should be noted that when an element is referred to as being "disposed on" another element, it may be directly on the other element or there may be an element centered thereon. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an element centered thereon. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only embodiments.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0033] Example 1

[0034] The present invention provides a condenser online leak detection device based on condenser vacuum detection, comprising a cooling water level measurement and control system, a condenser vacuum measurement system, an air compressor and compressed air delivery system, and a data collection and analysis system;

[0035] The cooling water level measurement and control system includes a level gauge provided on the condenser 1, a cooling water inlet chamber drain valve 3, and a cooling water outlet chamber drain valve 12;

[0036] The condenser vacuum degree measurement system includes a vacuum pressure gauge 15 and a pressure transmitter 16; the vacuum pressure gauge 15 and the pressure transmitter 16 are connected in sequence to obtain the internal vacuum degree of the condenser 1;

[0037] The air compressor and compressed air delivery system includes an air inlet compressor 10; the air inlet compressor 10 is used to pump oxygen into the cooling water inlet chamber of the condenser 1;

[0038] The data collection and analysis system includes a condenser leaking heat exchange tube positioning module 11 , and the pressure transmitter 16 and the air inlet compressor 10 are both electrically connected to the condenser leaking heat exchange tube positioning module 11 .

[0039] The principle is:

[0040] When the condenser drain level reaches the location of the leaking pipe bank, a large amount of compressed air will enter the condenser steam side, causing the condenser vacuum pressure to change immediately. The location of the leaking pipe bank can be determined by the corresponding relationship between the condenser vacuum pressure change and the drain level.

[0041] The present invention can locate the leaking heat exchange tube without maintenance personnel entering the condenser water chamber, greatly reducing the workload of leak detection, alleviating the work intensity of maintenance personnel, improving work efficiency, and reducing safety risks; the present invention saves leak detection time through online real-time detection.

[0042] The present invention also provides a method for online leak detection of a condenser based on condenser vacuum detection, comprising the following steps:

[0043] When a condenser leaks, after determining the water chamber where the leaking heat exchange tube is located, the unit load is reduced, and the condenser leaking heat exchange tube positioning module 11 adjusts the opening of the cooling water inlet chamber drain valve 3 and the cooling water outlet chamber drain valve 12, isolating and draining half of the condenser;

[0044] Start the air compressor and compressed air delivery system, the air compressor 10 starts to operate, and the opening of the pressure reducing valve 8 is adjusted to continuously deliver compressed air to the condenser cooling water inlet chamber;

[0045] Open the sampling valve 14 of the condenser vacuum measurement system, and the condenser leakage heat exchange pipe positioning module 9 collects the pressure data of the condenser vacuum measurement system pressure transmitter 16 in real time; determine the leakage pipe row position through the correspondence between the condenser vacuum pressure change and the water discharge level.

[0046] Start the air compressor and compressed air delivery system, adjusting the pressure to 0.3-0.6 MPa and the opening to 200-400 ml / min. When adjusting the openings of the cooling water inlet chamber drain valve 3 and the cooling water outlet chamber drain valve 10, control the cooling water chamber water level drop rate to 10-30 mm / min. The condenser leaking heat exchange tube locating module 9 generates a real-time dual-axis curve of time, condenser vacuum, and drain level.

[0047] The positioning method of the present invention fully utilizes the leakage detection device and the condenser vacuum degree measurement system matched with the condenser, and can realize online positioning of the leaking heat exchange tube of the condenser.

[0048] Example 2

[0049] like Figure 1 As shown, the present invention provides an online condenser leak detection device and method based on condenser vacuum detection. The system includes a cooling water level measurement and control system, a condenser vacuum measurement system, an air compressor and compressed air delivery system, and a data collection and analysis system.

[0050] The cooling water level measurement and control system includes a cooling water inlet chamber level gauge 2, a cooling water inlet chamber drain valve 3 and a cooling water outlet chamber drain valve 12 arranged on the condenser 1;

[0051] The condenser vacuum degree measurement system includes a sampling valve 14, a vacuum pressure gauge 15, and a pressure transmitter 16, which are connected in sequence;

[0052] The air compressor and compressed air delivery system includes an air intake manual valve 4, a flow meter 5, a tubular filter 6, a pressure gauge 7, a pressure reducing valve 8, a safety valve 9, and an air compressor 10. The air intake manual valve 4, the flow meter 5, the tubular filter 6, the pressure gauge 7, the pressure reducing valve 8, the safety valve 9, and the air compressor 10 are connected in sequence;

[0053] The data collection and analysis system includes a condenser leaking heat exchange tube positioning module 11 , and the air compressor and compressed air delivery system, cooling water level measurement and control system, and condenser vacuum measurement system are all electrically connected to the condenser leaking heat exchange tube positioning module 11 .

[0054] After determining the water chamber where the leaking heat exchange tube is located, the system of the present invention reduces the unit load and gradually drains the cooling water from the leaking water chamber. During the draining process, compressed air at a pressure of 0.3 to 0.6 MPa is introduced. When the drain reaches the location of the leaking tube row, a large amount of compressed air enters the steam side of the condenser, causing the condenser vacuum to change accordingly. The corresponding relationship between the condenser vacuum change and the drain level can be used to locate the leaking heat exchange tube in a specific row, significantly narrowing the scope of leak detection and reducing the workload of leak detection personnel. The method of the present invention is fast, accurate, low-cost, and highly reliable, providing a reliable decision-making basis for power plants to handle condenser leaks without shutting down.

[0055] Specifically, the cooling water inlet chamber level gauge 2 and the cooling water outlet chamber level gauge 13 in the cooling water level control system display the water level in their respective chambers in real time and transmit water level signals. The "0" value on the level gauges is based on the bottom plate of the chamber, and the highest water level is no lower than the height of the top row of heat exchange tubes, with a display accuracy of no less than 1 cm.

[0056] In the condenser vacuum measurement system, the condenser vacuum is measured by opening the sampling valve 14 and starting the pressure transmitter 16. The pressure transmitter 16 transmits the value to the condenser leakage heat exchange tube positioning module 11. The condenser leakage heat exchange tube positioning module 11 converts the pressure value into a condenser vacuum value and monitors the changes in the condenser vacuum value in real time.

[0057] The condenser leakage heat exchange tube positioning module 11 in the data collection and analysis system can respectively control the cooling water level control system, the air compressor and the compressed air delivery system, collect the values ​​from the cooling water inlet chamber level gauge 2, the cooling water outlet chamber level gauge 13 and the pressure transmitter 16 of the condenser vacuum measurement system in real time, and draw them into a time-condenser vacuum-drain level dual-axis curve, and determine the position of the leaking pipe row through the corresponding relationship between the condenser vacuum change and the drain level.

[0058] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0059] Example 3

[0060] Taking a 600MW supercritical unit as an example, when a condenser leak occurs, the condenser leak detection device first locates the water chamber where the leaking heat exchange tube is located. Then, the unit load is reduced to below 70%. The condenser leaking heat exchange tube positioning module 11 adjusts the opening of the cooling water inlet chamber drain valve 3 and the cooling water outlet chamber drain valve 12 to control the cooling water chamber water level drop rate to 20mm / min.

[0061] Start the air compressor and compressed air delivery system, the air compressor 10 starts to run, adjust the opening of the pressure reducing valve 8 so that the value of the pressure gauge 7 is 0.5MPa, adjust the opening of the air intake manual valve so that the float of the air intake flow meter is at 300ml / min, and continuously deliver the compressed air to the condenser cooling water inlet chamber.

[0062] Open the sampling valve 14 and the pressure transmitter 16 of the condenser vacuum measurement system, observe whether the values ​​of the vacuum pressure gauge 15 and the pressure transmitter 16 are close, and determine whether the performance of the vacuum pressure gauge 15 and the pressure transmitter 16 is normal.

[0063] The condenser leaking heat exchanger tube locating module 11 collects real-time pressure data from the condenser vacuum measurement system's pressure transmitter 16 and converts this pressure into the condenser's real-time vacuum value. When the condenser drain reaches the location of the leaking pipe bank, a large amount of compressed air enters the condenser steam side. At this point, the condenser vacuum pressure gauge 15 and the pressure transmitter 16 change immediately and synchronously. The condenser leaking heat exchanger tube locating module 11 monitors the vacuum changes in real time and determines the location of the leaking pipe bank based on the corresponding relationship between the condenser vacuum changes and the drain level. The module not only plots a dual-axis curve of time, condenser vacuum, and drain level, but also displays the location and height of the leaking pipe bank, facilitating timely leak repair.

[0064] It should be understood that the above description is for illustrative purposes only and is not intended to be limiting. Many embodiments and many applications beyond the examples provided will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of the present teachings should not be determined with reference to the above description, but rather with reference to the preceding claims and the full scope of equivalents to which such claims are entitled. For the purpose of completeness, all articles and references, including disclosures of patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein from the preceding claims is not a disclaimer of such subject matter, nor should it be considered that the applicants did not consider such subject matter to be part of the disclosed inventive subject matter.

Claims

1. A leak detection method for a condenser online leak detection device based on condenser vacuum detection, characterized in that: Including cooling water level measurement and control system, condenser vacuum measurement system, air compressor and compressed air delivery system, data collection and analysis system; The cooling water level measurement and control system comprises a liquid level gauge provided on the condenser (1), a cooling water inlet chamber drain valve (3), and a cooling water outlet chamber drain valve (12); The condenser vacuum degree measurement system comprises a vacuum pressure gauge (15) and a pressure transmitter (16); the vacuum pressure gauge (15) and the pressure transmitter (16) are connected in sequence to obtain the internal vacuum degree of the condenser (1); The air compressor and compressed air delivery system includes an air inlet compressor (10); the air inlet compressor (10) is used to pump oxygen into the cooling water inlet chamber of the condenser (1); The data collection and analysis system comprises a condenser leaking heat exchange tube positioning module (11), and the pressure transmitter (16) and the air inlet compressor (10) are both electrically connected to the condenser leaking heat exchange tube positioning module (11); The condenser vacuum degree measurement system further comprises a sampling valve (14); the sampling valve (14), a vacuum pressure gauge (15) and a pressure transmitter (16) are arranged in sequence, and the sampling valve (14) is arranged close to the condenser (1); The air compressor and compressed air delivery system further comprises an air intake electric valve (4), a flow meter (5) and a pressure gauge (7); the air intake electric valve (4), the flow meter (5), the pressure gauge (7) and the air compressor (10) are connected in sequence, and the air intake electric valve (4) is connected to the cooling water inlet chamber of the condenser (1); the air intake electric valve (4), the flow meter (5) and the pressure gauge (7) are all electrically connected to the condenser leakage heat exchange tube positioning module (11); The leak detection method comprises the following steps: When a condenser leaks, after determining the water chamber where the leaking heat exchange tube is located, the unit load is reduced, and the condenser leaking heat exchange tube positioning module (11) adjusts the opening of the cooling water inlet chamber drain valve (3) and the cooling water outlet chamber drain valve (12), and isolates and drains half of the condenser; Start the air compressor and the compressed air delivery system, the air compressor (10) starts to operate, and the opening of the pressure reducing valve (8) is adjusted to continuously deliver the compressed air to the condenser cooling water inlet chamber; The sampling valve (14) of the condenser vacuum measurement system is opened, and the condenser leakage heat exchange pipe positioning module (9) collects the pressure data of the condenser vacuum measurement system pressure transmitter (16) in real time; the leakage pipe row position is determined through the corresponding relationship between the condenser vacuum pressure change and the water discharge level; Start the air compressor and the compressed air delivery system and adjust the pressure to 0.3~0.6MPa and the opening to 200~400ml / min; When adjusting the opening of the cooling water inlet chamber drain valve (3) and the cooling water outlet chamber drain valve (10), the cooling water chamber water level drop speed is controlled to be 10-30 mm / min; The air compressor and compressed air delivery system further comprises a pressure reducing valve (8) and a safety valve (9); the air compressor (10), the safety valve (9), the pressure reducing valve (8) and the pressure gauge (7) are connected in sequence; The liquid level meter is at least one of a cooling water inlet chamber liquid level meter (2) and a cooling water outlet chamber liquid level meter (13); The "0" level line of the liquid level gauge is based on the bottom plate of the water chamber. The highest water level is not lower than the height of the top row of heat exchange tubes of the condenser, and the display accuracy is not less than 1 cm.

2. The leak detection method according to claim 1, wherein: The condenser leakage heat exchange tube positioning module (9) provides a time-condenser vacuum-drain level double-axis curve in real time.

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