A method for exogenous dynamic micro-positive pressure protection and measurement based on a cellular network

Abstract

The application discloses an exogenous dynamic micro-positive pressure protection and measurement method based on a cellular network, relates to the technical field of steam turbine generators, and is suitable for the protection operation of 350,000-kilowatt air-cooled steam turbine generator units in long-term sea transportation or humid environment storage. The application adopts an exogenous micro-positive pressure working principle, does not need to set large special equipment or complex special tooling, does not occupy extra space, does not need a large amount of manual inspection and maintenance, and can realize full-automatic inspection, monitoring, early warning, correction and protection. The application can realize the moisture-proof, rust-proof and protection requirements of 350,000-kilowatt air-cooled steam turbine generator units in long-term sea transportation or humid environment storage, and has the characteristics of low cost, high stability and strong adaptability.

Description

Technical Field

[0001] This invention relates to the field of steam turbine generator technology, and in particular to an exogenous dynamic micro-positive pressure protection and measurement method based on cellular networks, which is applicable to the long-term marine or humid environment storage protection operation of 350 MW class air-cooled steam turbine generator sets. Background Technology

[0002] The 350MW air-cooled steam turbine generator is nearly 10 meters long and 4.5 meters in diameter, classifying it as a large steam turbine generator set with a complex internal structure and numerous components. During long-term sea transport or storage in humid environments, without proper protection, its internal stator core is highly susceptible to moisture and rust, resulting in significant cost losses. Due to its enormous size, the integrated sealed enclosure commonly used for smaller generator sets cannot be employed. The current traditional protection method involves placing a large amount of desiccant inside the unit, while sealing all openings on both sides of the generator and the entire casing with conformally placed metal covers secured with rubber sealing strips. The metal covers are bolted in place. Theoretically, this method protects the generator by sealing off external airflow and simultaneously removing internal humidity. However, traditional protection methods are ineffective, mainly due to two unresolved issues: First, in actual operation, the large size of the unit, with over 30 openings of varying sizes and shapes on its outer surface, results in numerous and large open structures requiring sealing. During hoisting, transportation, and storage, vibrations and deformations inevitably occur, causing the metal covers on the outer surface to become loose, allowing humid air to enter and damage internal components. Second, even if all the sealed covers remain intact upon arrival at the transport ship or location, the rubber sealing strips that mate with the metal covers will inevitably lose elasticity and fail to provide a tight seal after a period of time due to prolonged exposure to temperature fluctuations and humid, salty air. This allows external humid, salty air to gradually enter the unit, causing widespread moisture damage and rust on components, resulting in significant cost losses. Therefore, we need a process that can effectively deoxygenate and prevent moisture inside the unit for a long time even when it cannot be completely sealed. This method must be able to adapt to the requirements of long-term sea transport or storage in humid environments, and because the protection period is long, this method must be able to achieve real-time monitoring and protection. Summary of the Invention

[0003] In view of this, the purpose of this invention is to disclose an exogenous micro-positive pressure protection and measurement method based on a cellular network. This method utilizes an exogenous micro-positive pressure working principle, requires no large-scale proprietary equipment or complex proprietary tooling, occupies no extra space, requires minimal manual supervision and maintenance, and provides fully automated inspection, monitoring, early warning, correction, and protection. It can meet the protection requirements of 350MW-class air-cooled steam turbine generator sets for long-term marine or humid environments, and features low cost, high stability, and strong adaptability. The technical solution of this invention includes the following steps:

[0004] Step 1: Set up measurement points: Bury 4 inert gas concentration meters inside the steam turbine generator, with each pair spaced 2 meters apart and evenly distributed along the axial direction;

[0005] Step 2: Set up inert gas input points; Install one inert gas input device at the center of the outer side of turbine generator cover plate A using a clamping mechanism; Install one inert gas input device at the center of the outer side of turbine generator cover plate B using a clamping mechanism.

[0006] Step 3: Conduct a leak test: Install test gas tank A into all inert gas input devices and charge the turbine generator with constant pressure saturation at 1 kPa for 30-45 minutes. After visually observing red gas escaping from the outer surface of the turbine generator, mark all leak points with a marker. After completion, close the inert gas input device, open the ventilation valve A, replace test gas tank A in the inert gas input device with test gas tank B, and quickly charge the turbine generator with 5 kPa until no red gas is visible escaping from the opened ventilation valve A. Continue charging while remotely turning on the inert gas concentration meter and observing the reading. When all inert gas concentration meters show a reading ≥85% and remain stable for more than 3 minutes, close the inert gas input device and close the ventilation valve A.

[0007] Step 4: Seal the leaks: Apply sealant to all leaks in a saturated manner, wait 60 minutes for the sealant to set, and then securely seal with industrial non-residual tape.

[0008] Step 5, Protective Operation: Install the working gas tank into the inert gas input device, fully open the ventilation valve B, and quickly charge the turbine generator with 5 kPa pressure. When all inert gas concentration gauge readings are ≥90% and can remain stable for more than 3 minutes, and no light green gas escapes from the ventilation valve B, close the inert gas input device and quickly close the ventilation valve B. Then open and adjust the input pressure of the inert gas input device to 0.1 kPa. When all inert gas concentration gauge readings are ≥95% and can remain stable for more than 3 minutes, close the inert gas input device.

[0009] Step 6: Preset and maintain a slight positive pressure state: Set the inert gas concentration meter alarm value to 90%, and set the inert gas input device input pressure to 0.05 kPa. The inert gas input device will continuously and slowly input at 0.05 kPa only when a hold signal is received, maintaining a slight positive pressure state inside the turbine generator.

[0010] Step 7: Failure Warning and Automatic Correction. An alarm signal is issued when the detection value of any inert gas concentration meter is <90%. Upon receiving the alarm signal, the inert gas input device automatically increases the input pressure until all inert gas concentration meters detect values ​​≥90% and issue a hold signal. Then, the inert gas input device automatically adjusts the input pressure to 0.05 kPa and continues to slowly input the gas. This process is automated via a cellular network connection and simultaneously generates information alerts and process records on the user interface.

[0011] Step 7 also includes:

[0012] Step 7.1, First-order correction: When the inert gas input device, which is under slight positive pressure, receives an alarm signal from the inert gas concentration meter, it automatically adjusts the input pressure to 0.1 kPa for continuous input according to the preset program.

[0013] Step 7.2, Second-order correction: If the inert gas input device does not receive a holding signal from the inert gas concentration meter within 10 minutes of running according to step 7.1, the inert gas input device will automatically adjust the input pressure to 0.15 kPa and continue inputting;

[0014] Step 7.3, Third-order correction: If the inert gas input device does not receive a holding signal from the inert gas concentration meter within 5 minutes of running according to step 7.2, the inert gas input device will automatically adjust the input pressure to 0.3 kPa for rapid input;

[0015] In the above-mentioned exogenous dynamic micro-positive pressure protection and measurement method based on cellular networks, the inert gas concentration meter remotely transmits measurement data to the operator based on the cellular network, and can issue alarm and hold signals according to preset values. The warning logic of the inert gas concentration meter is that an alarm signal is issued when the detection value of any one of the four inert gas concentration meters is <90%, and a hold signal is issued when the detection values ​​of all four inert gas concentration meters are ≥90%.

[0016] In the above-mentioned exogenous dynamic micro-positive pressure protection and measurement method based on cellular networks, the inert gas input device is linked with the inert gas concentration meter, remotely receives alarm and hold signals based on the cellular network, automatically adjusts the input pressure, and forms a process record to provide real-time feedback to the operator.

[0017] In the aforementioned exogenous dynamic micro-positive pressure protection and measurement method based on cellular networks, the test gas tank A contains a tracer gas, which is low-density, highly fluid, and red. The test gas tank B contains a mixed gas of carbon dioxide and inert gas, which is relatively high-density, low-fluidity, and pale green. The working gas tank contains a deoxygenated, moisture-free, inert mixed gas that is colorless.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] After using the method of this invention, a slightly positive pressure environment can be formed inside the steam turbine generator, that is, the air pressure inside the steam turbine generator is slightly greater than that outside. At this time, even if there are several unsealed air gaps in the steam turbine generator, the gas flow direction at the air gap location is always from inside to outside. This prevents the external humid and salty air from flowing into the steam turbine generator through the unsealed air gaps. By using slightly positive pressure, the unidirectional flow of air between the inside and outside is achieved, and the external airflow cannot enter the steam turbine generator. Secondly, this invention continuously injects deoxygenated and moisture-free inert mixed gas into the steam turbine generator, so that the oxygen content and humidity inside the steam turbine generator approach zero, thereby achieving long-term effective deoxygenation inside the unit under unsealed conditions. The purpose of oxygen-free protection is threefold: First, the invention innovatively employs a concentration measurement method to determine whether the protection requires correction. Compared to pressure or humidity measurements, the concentration measurement method is more sensitive and accurate, providing rapid and effective early warning signals to prevent device failure. Second, the invention abandons the traditional design concept of pursuing complete sealing and instead adopts a continuous improvement approach. It uses all-time concentration monitoring and early warning linked to a cellular network to control the inert gas input device to adjust the input pressure as needed, thereby ensuring that the turbine generator is in a slightly positive pressure protection state at all times. At the same time, early warnings and various operations are transmitted to the operator in real time through the cellular network, so that the operator can perform timely inspection and maintenance, saving a lot of human resources. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall layout.

[0021] Figure 2 for Figure 1 A-direction view.

[0022] Figure 3 for Figure 1 View B.

[0023] Figure 4 for Figure 2 The C-direction view.

[0024] Figure 5 This is a schematic diagram of sealing a leak.

[0025] Figure 6 This is a flowchart illustrating the process of this method.

[0026] The markings in the diagram are as follows: 1-Steam turbine generator; 2-Inert gas concentration meter; 3-Steam turbine generator cover plate A; 4-Steam turbine generator cover plate B; 5-Inert gas input device; 7-Ventilator A; 10-Ventilator B; 11-Sealing cover plate C; 12-Sealing cover plate D; 13-Sealing cover plate E; 14-Sealing cover plate F; 15-Sealing cover plate G; 16-Sealing cover plate H; 17-Sealing cover plate J; 18-Sealing cover plate K; 19-Sealing cover plate L; 20-Sealing cover plate M; 21-Sealing cover plate N; 22-Location of sealant application; 23-Location of industrial non-residual adhesive tape; 24-Location of leak point. Detailed Implementation

[0027] The present invention will now be described in further detail with reference to the accompanying drawings.

[0028] A method for exogenous dynamic micro-positive pressure protection and measurement based on cellular networks includes the following steps:

[0029] Step 1: Set the measurement points. For example... Figure 4 As shown, four inert gas concentration meters 2 are embedded inside the steam turbine generator 1, with each pair spaced 2 meters apart and evenly distributed along the axial direction. This distribution method can improve the effective range of concentration monitoring and maximize the sensitivity and accuracy of the inert gas concentration meters 2.

[0030] Step 2: Set the inert gas input point. For example... Figure 2 , Figure 3 As shown, an inert gas input device 5 is installed at the center of the outer side of the turbine generator cover plate A3 using a clamping mechanism; another inert gas input device 5 is installed at the center of the outer side of the turbine generator cover plate B4 using a clamping mechanism. Since the turbine generator set is nearly 10 meters long, inert gas input devices 5 are installed at its leftmost and rightmost ends respectively. Inert gas is input from the edge towards the center, resulting in the best filling effect and minimizing the appearance of blank areas.

[0031] Step 3: Conduct a leak test. For example... Figure 1As shown, test gas cylinders A6 are installed in all inert gas input devices 5, and the turbine generator 1 is charged with constant pressure saturation at 1 kPa for 30-45 minutes. After visually observing red gas escaping from the outer surface of the turbine generator 1, all leakage points are marked with a marker. After completion, the inert gas input device 5 is closed, the ventilation valve A7 is opened, and the test gas cylinders A6 in the inert gas input device 5 are replaced with test gas cylinders B8. The turbine generator 1 is quickly charged with 5 kPa until no red gas is visible escaping from the opened ventilation valve A7. The charging continues, and the inert gas concentration meter 2 is remotely turned on and the reading is observed. When the readings of all inert gas concentration meters 2 are ≥85% and can be stably maintained for more than 3 minutes, the inert gas input device 5 is closed and the ventilation valve A7 is closed. Test gas tank A6 contains tracer gas, which is low-density, highly fluid, and red. After saturation filling, red gas will seep out from all air gaps and leaks on the outer surface of turbine generator 1, making it easy for maintenance personnel to mark them. Test gas tank B8 contains a mixture of carbon dioxide and inert gas, which is relatively high-density, low-fluidity, and light green. After filling it, because its density is greater than that of the tracer gas in test gas tank A6, opening the ventilation valve A7 can completely replace the tracer gas filled in test gas tank A6.

[0032] Step 4: Seal the leak. For example... Figure 5 As shown, apply saturated sealant to all leak points and seal them. Wait 60 minutes for the sealant to set, then use industrial non-marking tape to firmly seal all leak points 24 of the turbine generator 1. This helps to reduce air gaps.

[0033] Step 5, Protective Operation. Insert the working gas tank 9 into the inert gas input device 5, fully open the ventilation valve B10, and rapidly charge the turbine generator 1 with gas at a pressure of 5 kPa. When the readings of all inert gas concentration gauges 2 are ≥90% and remain stable for more than 3 minutes, and no pale green gas escapes from the ventilation valve B10, close the inert gas input device 5 and quickly close the ventilation valve B10. Then, open and adjust the input pressure of the inert gas input device 5 to 0.1 kPa. When the readings of all inert gas concentration gauges 2 are ≥95% and remain stable for more than 3 minutes, close the inert gas input device 5. The working gas tank 9 contains a deoxygenated, moisture-free, colorless inert gas mixture. Fill the turbine generator 1 completely, ensuring a concentration of 95%. At this point, the oxygen content inside the turbine generator 1 is extremely low, and water molecules are close to zero, placing it in a dry, oxygen-free protective state.

[0034] Step 6: Preset and maintain a slight positive pressure state. For example... Figure 6As shown, the alarm value of the inert gas concentration meter 2 is set to 90%, and the input pressure of the inert gas input device 5 is set to 0.05 kPa. The inert gas input device 5 continuously and slowly inputs at 0.05 kPa only when a hold signal is received, so as to maintain the micro-positive pressure state inside the turbine generator 1.

[0035] Step 7, Failure Warning and Automatic Correction. For example... Figure 6 As shown, when any inert gas concentration meter 2 detects a value <90%, an alarm signal is issued. Upon receiving the alarm signal, the inert gas input device 5 automatically increases the input pressure until all inert gas concentration meters 2 detect a value ≥90% and issue a hold signal. Then, the inert gas input device 5 automatically adjusts the input pressure to 0.05 kPa and continues to slowly input the gas. This process is conducted automatically via a cellular network connection, and information alerts and process records can be generated on the user interface.

[0036] Furthermore, such as Figure 6 As shown, step 7 should include the following steps:

[0037] Step 7.1, First-order correction. When the inert gas input device 5, which is under slight positive pressure, receives the alarm signal from the inert gas concentration meter 2, the inert gas input device 5 automatically adjusts the input pressure to 0.1 kPa for continuous input according to the preset program.

[0038] Step 7.2, Second-order correction. If the inert gas input device 5 does not receive a hold signal from the inert gas concentration meter 2 within 10 minutes of operation according to step 7.1, the inert gas input device 5 will automatically adjust the input pressure to 0.15 kPa and continue inputting.

[0039] Step 7.3, Third-order correction. If the inert gas input device 5 does not receive a hold signal from the inert gas concentration meter 2 within 5 minutes of running according to step 7.2, the inert gas input device 5 automatically adjusts the input pressure to 0.3 kPa for rapid input.

[0040] like Figure 6 As shown, the inert gas concentration meter 2 remotely transmits measurement data to the operator via a cellular network and can issue alarm and hold signals according to preset values. The warning logic of the inert gas concentration meter 2 is as follows: when the detection value of any one of the four inert gas concentration meters 2 is <90%, an alarm signal is issued; when the detection values ​​of all four inert gas concentration meters 2 are ≥90%, a hold signal is issued. The inert gas input device 5 is linked with the inert gas concentration meter 2, remotely receives alarm and hold signals via a cellular network, automatically adjusts the input pressure, and forms a process record that is fed back to the operator in real time.

[0041] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. However, these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for exogenous dynamic micro-positive pressure protection and measurement based on a cellular network, characterized in that: It includes the following steps: Step 1, Set up measurement points: Bury 4 inert gas concentration meters (2) inside the steam turbine generator (1), with a 2-meter interval between each pair, and evenly distributed along the axial direction; Step 2: Set up inert gas input points: Install one inert gas input device (5) at the center of the outer side of the turbine generator cover plate A (3) by means of a clamping mechanism; Install one inert gas input device (5) at the center of the outer side of the turbine generator cover plate B (4) by means of a clamping mechanism. Step 3: Conduct a leak test: Install test gas tank A (6) into all inert gas input devices (5), and charge the steam turbine generator (1) with constant pressure saturation at 1 kPa for 30-45 minutes. After visually observing the red gas escaping from the outer surface of the steam turbine generator (1), mark all leak points with a marker. After completion, close the inert gas input device (5), open the ventilation valve A (7), replace the test gas tank A (6) in the inert gas input device (5) with test gas tank B (8), and charge the steam turbine generator (1) quickly at 5 kPa until no red gas escapes from the open ventilation valve A (7). Continue charging while remotely turning on the inert gas concentration meter (2) and observing the reading. When the readings of all inert gas concentration meters (2) are ≥85% and can be stably maintained for more than 3 minutes, close the inert gas input device (5) and close the ventilation valve A (7). Step 4: Seal the leaks: Apply sealant to all leaks in a saturated manner and seal them. Wait 60 minutes for the sealant to set, and then use industrial non-residual tape to firmly seal them. Step 5, Protective Operation: Insert the working gas tank (9) into the inert gas input device (5), fully open the ventilation valve B (10), and quickly charge the steam turbine generator (1) at a pressure of 5 kPa. When the readings of all inert gas concentration meters (2) are ≥90% and can be maintained stably for more than 3 minutes, and no light green gas escapes from the ventilation valve B (10), close the inert gas input device (5), quickly close the ventilation valve B (10), and then open and adjust the input pressure of the inert gas input device (5) to 0.1 kPa. When the readings of all inert gas concentration meters (2) are ≥95% and can be maintained stably for more than 3 minutes, close the inert gas input device (5). Step 6: Preset and maintain a micro-positive pressure state: Set the alarm value of the inert gas concentration meter (2) to 90%, set the input pressure of the inert gas input device (5) to 0.05KPa, and only when a hold signal is received, the inert gas input device (5) continuously and slowly inputs at 0.05KPa to maintain the micro-positive pressure state inside the steam turbine generator (1); Step 7, Failure Indication and Automatic Correction: When the detection value of any inert gas concentration meter (2) is <90%, an alarm signal is issued. After receiving the alarm signal, the inert gas input device (5) automatically increases the input pressure until the detection values ​​of all inert gas concentration meters (2) are ≥90% and a hold signal is issued. Then, the inert gas input device (5) automatically adjusts the input pressure to 0.05KPa and continues to input slowly.

2. The exogenous dynamic micro-positive pressure protection and measurement method based on a cellular network according to claim 1, characterized in that: The warning logic of the inert gas concentration meter (2) is as follows: when the detection value of any one of the four inert gas concentration meters (2) is <90%, an alarm signal is issued; when the detection values ​​of all four inert gas concentration meters (2) are ≥90%, a hold signal is issued.

3. The exogenous dynamic micro-positive pressure protection and measurement method based on a cellular network according to claim 1, characterized in that: The inert gas input device (5) is linked with the inert gas concentration meter (2). It remotely receives alarm and hold signals based on the cellular network, automatically adjusts the input pressure, and forms a process record to provide real-time feedback to the operator.

4. The exogenous dynamic micro-positive pressure protection and measurement method based on a cellular network according to claim 1, characterized in that: The test gas tank A (6) contains tracer gas, which is low in density, highly fluid, and red. The test gas tank B (8) contains a mixture of carbon dioxide and inert gas, which is relatively high in density, low in fluidity, and light green. The working gas tank (9) contains a deoxygenated, moisture-free, inert mixed gas, which is colorless.

5. The exogenous dynamic micro-positive pressure protection and measurement method based on a cellular network according to claim 1, characterized in that: Step 7 also includes: Step 7.1, First-order correction: When the inert gas input device (5) under a slightly positive pressure state receives the alarm signal from the inert gas concentration meter (2), according to the preset program, the inert gas input device (5) automatically adjusts the input pressure to 0.1KPa for continuous input; Step 7.2, Second-order correction: If the inert gas input device (5) does not receive a holding signal from the inert gas concentration meter (2) within 10 minutes of running according to step 7.1, the inert gas input device (5) will automatically adjust the input pressure to 0.15 kPa and continue inputting; Step 7.3, Third-order correction: If the inert gas input device (5) does not receive a hold signal from the inert gas concentration meter (2) within 5 minutes of running according to step 7.2, the inert gas input device (5) automatically adjusts the input pressure to 0.3KPa for rapid input.

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