Protection device and method for preventing water impact of steam turbine

Abstract

The invention relates to the technical field of steam turbines, and discloses a protection device and method for preventing water impact of a steam turbine, and the device comprises a conductivity measuring point 1 which is disposed on a steam inlet pipeline of the steam turbine and is used for monitoring the conductivity change of a medium in the pipeline; and the conductivity measuring point 2, the conductivity measuring point 3 and the conductivity measuring point 4 are arranged on the steam extraction and exhaust pipeline and are used for monitoring the conductivity change of a medium in the pipeline. According to the invention, different conductivities among demineralized water, wet steam and dry steam are utilized to more accurately detect whether water is contained in the steam inlet pipeline and the steam extraction and exhaust pipeline of the steam turbine, even trace water can be detected, the detection sensitivity and accuracy are improved, the conductivity of the medium in the pipeline is monitored in real time, and the detection accuracy is improved. And protection measures such as alarming and steam turbine jumping stop are taken in time when abnormity is detected, so that steam turbine water impact accidents caused by steam with water are effectively prevented, and the intrinsic safety of equipment operation is improved.

Description

Technical Field

[0001] The invention relates to the technical field of steam turbines, and in particular to a protection device and method for preventing water hammer from occurring in steam turbines. Background Art

[0002] In the prior art, a single electrical contact is installed on the inner wall at the bottom of a high-temperature steam pipe to detect whether there is condensed water. This detection method relies on the conductive properties of water and the non-conductive properties of steam, that is, when a conductive path is formed between the electrical contact and the pipe wall, it indicates that there is water in the pipe; conversely, if the two are in an open circuit state, it is considered that there is no water in the pipe. However, this method has limitations, especially when the amount of condensed water is small, the water may be dispersed in the form of beads inside the pipe without contacting the electrical contact, or even if there is a small amount of condensed water, a sufficient conductive path cannot be established between the electrical contact and the pipe wall. Therefore, when there is a trace amount of condensed water in the steam, the detection method cannot effectively identify it, resulting in incomplete and inaccurate detection results. Summary of the invention

[0003] In view of the problems existing in the above-mentioned existing protective device and method for preventing water hammer from occurring in a steam turbine, the present invention is proposed.

[0004] Therefore, the object of the present invention is to provide a protective device and method for preventing water hammer in a steam turbine, and its purpose is to provide a device which utilizes the difference in electrical conductivity of desalted water, wet steam, and dry steam to accurately and sensitively detect whether steam carries water, the degree of water carrying, or pure water entering the steam turbine inlet and exhaust steam pipes.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: A protective device for preventing water hammer in a steam turbine comprises: a conductivity measuring point 1, which is arranged on a steam inlet pipe of the steam turbine and is used to monitor the conductivity change of a medium in the pipe;

[0006] Conductivity measuring point 2, conductivity measuring point 3, and conductivity measuring point 4 are set on the steam extraction and exhaust pipes to monitor the conductivity changes of the medium in the pipes.

[0007] As a preferred solution of the protective device for preventing water hammer of a steam turbine described in the present invention, the conductivity measuring point 1, the conductivity measuring point 2, the conductivity measuring point 3 and the conductivity measuring point 4 are connected to a distributed control system DCS.

[0008] As a preferred solution of the protective device for preventing water hammer of a steam turbine described in the present invention, the DCS is capable of receiving signals from conductivity measuring points and triggering corresponding alarms or tripping actions according to a preset conductivity threshold.

[0009] As a preferred solution of the protective device for preventing water hammer of a steam turbine according to the present invention, the DCS includes an alarm unit for sending an alarm signal when the conductivity measurement value exceeds a preset threshold value.

[0010] As a preferred solution of the protection device for preventing water hammer of a steam turbine according to the present invention, the DCS further comprises a shutdown unit for executing a shutdown operation when the conductivity measurement value exceeds another preset threshold value.

[0011] As a preferred solution of the protective device for preventing water hammer of a steam turbine described in the present invention, when the conductivity detected by the conductivity measuring point 1 exceeds 0.4μs / cm, the DCS sends an alarm signal; when the conductivity exceeds 10μs / cm, the DCS sends an emergency shutdown signal.

[0012] As a preferred solution of the protection device for preventing water hammer of a steam turbine described in the present invention, when the conductivity at the economizer inlet detected by the conductivity measuring point 2, the conductivity measuring point 3, and the conductivity measuring point 4 is less than 3μs / cm, the DCS sends an alarm signal and executes the actions of tripping the steam turbine and interlocking and closing related valves.

[0013] As a preferred solution of the protective device for preventing water hammer of a steam turbine described in the present invention, the conductivity measuring point 1, the conductivity measuring point 2, the conductivity measuring point 3, and the conductivity measuring point 4 can distinguish the conductivity differences among desalted water, wet steam and dry steam, thereby realizing accurate monitoring of the water content of the steam inlet of the steam turbine.

[0014] As a preferred solution of the protective device for preventing water hammer of a steam turbine described in the present invention, the conductivity measuring point 1, the conductivity measuring point 2, the conductivity measuring point 3, and the conductivity measuring point 4 are made of corrosion-resistant materials to adapt to high temperature and high pressure environments.

[0015] In order to solve the above technical problems, the present invention also provides the following technical solutions: including the above-mentioned protection device for preventing water hammer of a steam turbine, wherein: a. conductivity measuring points are installed on the steam inlet pipe and the exhaust steam pipe of the steam turbine; b. the conductivity of the medium in the pipe is continuously monitored by the conductivity measuring points; c. the data obtained by the conductivity measuring points are transmitted to the DCS; d. the DCS determines whether there is water-carrying phenomenon according to the preset conductivity threshold value, and if so, triggers the corresponding alarm or tripping action.

[0016] The beneficial effects of the present invention are as follows: by utilizing the different electrical conductivities among desalted water, wet steam and dry steam, it is possible to more accurately detect whether there is moisture in the steam inlet and exhaust pipes of the steam turbine. Even trace amounts of moisture can be detected, thereby improving the sensitivity and accuracy of the detection. By real-time monitoring of the electrical conductivity of the medium in the pipeline and taking protective measures such as alarming and stopping the steam turbine in a timely manner when an abnormality is detected, it is possible to effectively prevent water shock accidents of the steam turbine caused by water in the steam, thereby improving the inherent safety of the equipment operation and reducing the difficulty of accident judgment for the operating personnel. The automated monitoring system reduces the impact of human factors, reduces the misjudgment or omission of potential accidents by the operating personnel, simplifies the accident response process, and makes the operation easier and more reliable.

[0017] In summary, the protection device not only improves the protection capability against water hammer of the steam turbine, but also enhances the overall reliability of the system, while reducing the workload of operation and maintenance personnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0019] Figure 1 The logic diagram of the present invention is shown in FIG. Figure 1 .

[0020] Figure 2 The logic diagram of the present invention is shown in FIG. Figure 2 .

[0021] Figure 3 The logic diagram of the present invention is shown in FIG. Figure 3 .

[0022] Figure 4 It is a schematic diagram of the installation of the conductivity measuring point 1 of the present invention.

[0023] Figure 5 It is a schematic diagram of the installation of conductivity measuring points 2, 3, and 4 of the present invention. DETAILED DESCRIPTION

[0024] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0025] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0026] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0027] Secondly, the present invention is described in detail with reference to the schematic diagram. When describing the embodiments of the present invention in detail, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0028] Example 1

[0029] Reference Figures 1-2 , which is the first embodiment of the present invention, provides a protection device and method for preventing water hammer in a steam turbine. The device includes a conductivity measuring point 1, which is arranged on the steam inlet pipe of the steam turbine and is used to monitor the conductivity change of the medium in the pipe.

[0030] Specifically, conductivity measuring point 1, conductivity measuring point 2, conductivity measuring point 3, and conductivity measuring point 4 are connected to a distributed control system DCS.

[0031] Furthermore, the DCS can receive signals from the conductivity measuring points and trigger corresponding alarms or tripping actions according to preset conductivity thresholds. The DCS includes an alarm unit for sending an alarm signal when the conductivity measurement value exceeds the preset threshold.

[0032] Among them, when the conductivity detected by conductivity measuring point 1 exceeds 0.4μs / cm, DCS sends an alarm signal; when the conductivity exceeds 10μs / cm, DCS sends an emergency shutdown signal.

[0033] In summary, conductivity measuring point 1 is placed on the steam inlet pipe of the steam turbine, specifically used to monitor the conductivity changes of the medium inside the pipe. In addition, conductivity measuring points 2, 3 and 4 are also arranged in key parts of the steam turbine, such as the steam extraction and exhaust pipes. These measuring points work together to provide comprehensive monitoring coverage.

[0034] When the water content of steam is high, there will be condensed water or the humidity at the lower wall will be higher. The main steam pipe contains steam and needs to be more sensitive. Therefore, the measuring point is placed in the horizontal pipe and two electrodes are installed at the lower wall.

[0035] All conductivity measurement points are connected to the distributed control system (DCS). As a central control unit, the DCS can collect and process data from each conductivity measurement point in real time. Through the pre-set conductivity threshold, the DCS can intelligently determine whether there is too much moisture in the pipeline and respond accordingly. When the conductivity value detected by conductivity measurement point 1 exceeds 0.4μs / cm, it means that the steam in the steam inlet pipe may begin to carry a certain amount of moisture. At this time, the DCS will activate the alarm unit and send an alarm signal to the operating personnel to alert them to potential risks. If the conductivity further increases to more than 10μs / cm, it means that the moisture content has reached a dangerous level. The DCS will immediately initiate the emergency shutdown procedure and automatically cut off the power supply to the turbine to prevent serious damage caused by water shock.

[0036] Example 2

[0037] Reference Figures 1 to 3 , which is the second embodiment of the present invention. This embodiment is different from the first embodiment in that: conductivity measuring points 2, 3 and 4 are arranged on the steam extraction and exhaust pipes to monitor the conductivity changes of the medium in the pipes.

[0038] Furthermore, when the conductivity at the economizer inlet detected by conductivity measuring point 2, conductivity measuring point 3, and conductivity measuring point 4 is less than 3 μs / cm, the DCS sends an alarm signal and executes the actions of tripping the steam turbine and interlocking and closing related valves.

[0039] Furthermore, conductivity measuring point 1, conductivity measuring point 2, conductivity measuring point 3, and conductivity measuring point 4 can distinguish the conductivity difference between desalted water, wet steam, and dry steam, thereby realizing accurate monitoring of the water content of the turbine inlet steam.

[0040] When in use, conductivity measuring points 2, 3 and 4 are carefully set on the steam extraction and exhaust pipes to monitor the changes in medium conductivity at these key locations. This layout ensures effective monitoring of the entire steam cycle path of the steam turbine, especially those places prone to water leakage or feed water backflow.

[0041] When conductivity measuring point 2, conductivity measuring point 3 or conductivity measuring point 4 detects that the economizer inlet conductivity of the medium in the pipeline is less than 3μs / cm, it means that desalted water or wet steam may have appeared in the pipeline instead of normal dry steam. In this case, the distributed control system (DCS) will immediately issue an alarm signal to remind the operator to pay attention to the potential risk of water shock. At the same time, in order to prevent possible serious consequences, the DCS will automatically perform the operation of tripping the turbine and interlock the closing of related valves to prevent more water or wet steam from entering the turbine, thereby protecting the equipment from damage.

[0042] More importantly, all conductivity measuring points 1, 2, 3 and 4 have the ability to distinguish between different media, that is, they can identify the conductivity differences between desalted water, wet steam and dry steam. This function allows the system to not only detect whether there is moisture in the pipeline, but also accurately assess the degree of water in the inlet steam. This precise monitoring capability is crucial to preventing water shock because it allows the system to take action before the water content reaches a dangerous level, thereby effectively preventing damage to the steam turbine.

[0043] In exhaust pipes, what needs to be prevented is water backflowing into the steam turbine. Conductivity measuring points 2, 3 and 4 are installed on the vertical pipes. When water backflows, the vertical pipes will inevitably be filled.

[0044] By distinguishing the conductivity of different types of media, accurate monitoring of the water content in the turbine inlet steam is achieved, ensuring sensitivity to small changes. Once abnormal conductivity is detected, the DCS can quickly issue an alarm and implement necessary safety measures, greatly shortening the time interval from problem discovery to problem solving. By automatically tripping the turbine and closing the valve, the system can instantly interrupt the process that may cause water shock, greatly improving the safety performance of the equipment.

[0045] Example 3

[0046] Reference Figures 1 to 3 , which is the third embodiment of the present invention.

[0047] The operation process of this device is as follows: conductivity measuring point 1 is installed on the steam inlet pipe of the steam turbine, and conductivity measuring points 2, 3 and 4 are installed on the steam extraction and exhaust pipes. These measuring points are responsible for monitoring the conductivity changes of the media in their respective pipes.

[0048] All conductivity measurement points are connected to a distributed control system (DCS). The DCS serves as a central control unit and is responsible for receiving conductivity data from each measurement point and processing it according to preset thresholds.

[0049] For conductivity measuring point 1, two thresholds are set: when the detected conductivity exceeds 0.4μs / cm, the DCS issues an alarm signal; when the conductivity exceeds 10μs / cm, the DCS issues an emergency shutdown signal. For conductivity measuring points 2, 3, and 4, when the detected conductivity at the economizer inlet is less than 3μs / cm, the DCS issues an alarm signal and executes the actions of tripping the steam turbine and interlocking and closing related valves.

[0050] The conductivity measuring point continuously monitors the conductivity of the medium in the pipeline and transmits the data to the DCS in real time. The DCS determines whether there is water in the steam based on the preset conductivity threshold.

[0051] When the conductivity detected at conductivity measuring point 1 exceeds 0.4μs / cm, the DCS issues an alarm signal to alert the operator. If the conductivity continues to rise and exceeds 10μs / cm, the DCS will trigger an emergency shutdown signal and automatically stop the operation of the steam turbine. For conductivity measuring points 2, 3, and 4, when the conductivity at the economizer inlet is detected to be less than 3μs / cm, the DCS issues an alarm signal and immediately executes the operation of tripping the steam turbine, while interlocking and closing the relevant valves to prevent more moisture from entering the steam turbine.

[0052] According to actual on-site conditions, more measuring points are generally used to ensure stability and accuracy.

[0053] In summary, by using multiple conductivity measurement points, the device can comprehensively monitor the entire steam turbine system. Even the presence of trace moisture can be discovered in time, which greatly improves the accuracy of monitoring. Once an abnormal situation is detected, the DCS can respond quickly, whether it is a simple alarm or a complex trip operation, it can be completed in the shortest time, greatly reducing the possibility of potential accidents. Through effective management of steam water, the chance of water shock damage to the steam turbine is significantly reduced, the service life of the equipment is extended, and the continuity and stability of power production are ensured.

[0054] Importantly, it should be noted that the construction and arrangement of the present application shown in a plurality of different exemplary embodiments are only exemplary. Although only a few embodiments are described in detail in this disclosure, it should be readily understood by those who refer to this disclosure that many modifications are possible (e.g., the size, scale, structure, shape and proportion of various elements, and parameter values ​​(e.g., temperature, pressure, etc.), installation arrangement, use of materials, color, directional changes, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in the application. For example, the element shown as integrally formed can be composed of multiple parts or elements, the position of the element can be inverted or otherwise changed, and the nature or number or position of the discrete element can be changed or changed. Therefore, all such modifications are intended to be included in the scope of the present invention. The order or sequence of any process or method steps can be changed or reordered according to alternative embodiments. In the claims, any "device plus function" clause is intended to cover the structure of performing the function described herein, and is not only structurally equivalent but also equivalent structure. Without departing from the scope of the present invention, other replacements, modifications, changes and omissions can be made in the design, operating conditions and arrangement of the exemplary embodiments. Therefore, the invention is not limited to a specific embodiment, but extends to numerous modifications still falling within the scope of the appended claims.

[0055] Additionally, in order to provide a concise description of exemplary embodiments, all features of an actual embodiment (ie, those features that are not relevant to the best mode presently contemplated for carrying out the invention or those that are not relevant to implementing the invention) may not be described.

[0056] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A protective device for preventing water hammer from occurring in a steam turbine, characterized in that: include, Conductivity measuring point 1 is set on the steam inlet pipe of the steam turbine and is used to monitor the conductivity change of the medium in the pipe; Conductivity measuring point 2, conductivity measuring point 3, and conductivity measuring point 4 are set in the steam extraction and exhaust pipes to monitor the conductivity changes of the medium in the pipes.

2. A protective device for preventing water hammer from occurring in a steam turbine according to claim 1, characterized in that: The conductivity measuring point 1, the conductivity measuring point 2, the conductivity measuring point 3 and the conductivity measuring point 4 are connected to a distributed control system DCS.

3. A protection device for preventing water hammer from occurring in a steam turbine according to claim 2, characterized in that: The DCS can receive signals from conductivity measuring points and trigger corresponding alarms or tripping actions according to preset conductivity thresholds.

4. A protection device for preventing water hammer from occurring in a steam turbine according to claim 3, characterized in that: The DCS includes an alarm unit for issuing an alarm signal when the conductivity measurement value exceeds a preset threshold.

5. A protection device for preventing water hammer from occurring in a steam turbine according to claim 4, characterized in that: The DCS further comprises a shutdown unit for performing a shutdown operation when the conductivity measurement value exceeds another preset threshold value.

6. A protection device for preventing water hammer from occurring in a steam turbine according to claim 5, characterized in that: When the conductivity detected by the conductivity measuring point 1 exceeds 0.4 μs / cm, the DCS sends an alarm signal; when the conductivity exceeds 10 μs / cm, the DCS sends an emergency shutdown signal.

7. A protection device for preventing water hammer from occurring in a steam turbine according to claim 6, characterized in that: When the conductivity at the economizer inlet detected by the conductivity measuring point 2, the conductivity measuring point 3, and the conductivity measuring point 4 is less than 3 μs / cm, the DCS sends an alarm signal and executes the actions of tripping the steam turbine and interlocking and closing related valves.

8. The protective device for preventing water hammer from occurring in a steam turbine according to claim 7, characterized in that: The conductivity measuring point 1, the conductivity measuring point 2, the conductivity measuring point 3 and the conductivity measuring point 4 can distinguish the conductivity difference between desalted water, wet steam and dry steam, thereby realizing accurate monitoring of the water content of the turbine inlet steam.

9. A protection device for preventing water hammer from occurring in a steam turbine according to claim 8, characterized in that: The conductivity measuring point 1, the conductivity measuring point 2, the conductivity measuring point 3, and the conductivity measuring point 4 are made of corrosion-resistant materials to adapt to high temperature and high pressure environments.

10. A method for using a protective device for preventing water hammer from occurring in a steam turbine, characterized in that: A protective device for preventing water hammer from occurring in a steam turbine as claimed in any one of claims 1 to 9, comprising: a. Install conductivity measuring points on the steam inlet pipe and exhaust pipe of the steam turbine; b. Continuously monitor the conductivity of the medium in the pipeline through the conductivity measuring point; c. Transmit the data obtained from the conductivity measurement point to the DCS; d. DCS determines whether there is water in the system based on the preset conductivity threshold. If so, it triggers the corresponding alarm or trip action.

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