A protection method and system for preventing water hammer from occurring in a steam turbine

Abstract

The present invention discloses a protection method and system for preventing water hammer from occurring in a steam turbine, and relates to the technical field of steam turbine protection, and comprises the following steps: installing conductivity probes on the steam inlet pipe, the steam exhaust pipe, the extraction and exhaust steam pipe, and the shaft seal leakage steam pipe of the steam turbine, and setting the upper and lower limits of the conductivity for each conductivity probe; judging whether the steam at the corresponding position is in a water-carrying state by the conductivity signal collected by the conductivity probe; and performing interlocking protection by a DCS control system. The present invention installs conductivity measuring points on the steam inlet, extraction and exhaust steam, shaft seal leakage steam and other pipes of the steam turbine. When the steam inlet of the steam turbine carries water, the steam entering the steam turbine is in a wet steam state, and the conductivity at this time is greatly increased compared to the normal dry steam conductivity.

Description

Technical Field

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

[0002] The existing method of judging whether there is condensed water only by whether there is conductivity between a single electrical contact and the pipe wall is incomplete. When the amount of condensed water is small, the condensed water may condense into beads and not at the electrical contact, or the amount of condensed water is not enough to form a path between the electrical contact and the pipe wall. At this time, the condensed water in the steam cannot be detected. Summary of the invention

[0003] In view of the problems existing in the existing protection and system for preventing water hammer from occurring in steam turbines, the present invention is proposed.

[0004] Therefore, the problem to be solved by the present invention is that the judgment effect of the existing method is not comprehensive.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] In a first aspect, an embodiment of the present invention provides a method for protecting a steam turbine from water hammer, comprising the following steps:

[0007] Conductivity probes are installed on the steam turbine inlet pipe, steam turbine exhaust pipe, steam extraction and exhaust pipe, and shaft seal steam leakage pipe, and the upper and lower limits of conductivity are set for each conductivity probe;

[0008] The conductivity signal collected by the conductivity probe is used to determine whether the steam at the corresponding position is in a water-containing state;

[0009] Interlocking protection is carried out through the DCS control system.

[0010] As a preferred solution of the protection method for preventing water hammer of the steam turbine of the present invention, the upper limit value of the conductivity probe is the conductivity value of normal dry steam plus the conductivity change of the steam turbine running with water;

[0011] The lower limit of the conductivity probe is the conductivity value of normal dry steam minus the conductivity change when the turbine is running with water.

[0012] As a preferred solution of the protection method for preventing water hammer from occurring in a steam turbine according to the present invention, the operation steps of the DCS control system include:

[0013] When the conductivity probe on the steam inlet pipe of the steam turbine detects that the conductivity is greater than the set upper limit, it will enter the delayed tripping interlock;

[0014] When the conductivity is lower than the set lower limit again, the delayed tripping interlock is eliminated and a timer is added to the control logic;

[0015] After the trip, the timer starts timing. If the steam conductivity of the steam inlet pipe detected by the conductivity probe is greater than the set upper limit again after the timer reaches the set time, the timer is reset and the conductivity probe is flushed, and the timer is cleared;

[0016] The upper and lower limits of the conductivity probe on the exhaust steam pipe are set to 0 in the DCS control system. Multiple conductivity probes are installed on the exhaust steam pipe. If the conductivity detected by the conductivity probe at one position is greater than the set upper limit, it is determined that feed water backflow occurs on the exhaust steam pipe, and the timer is triggered;

[0017] If the detection values ​​of two consecutive conductivity probes are greater than the set upper limit at the same time, and the timer reaches the set time, the turbine will be started to shut down, so that the steam inlet, extraction and exhaust of the turbine will be interlocked and the turbine will enter the shutdown process;

[0018] If the conductivity probe detection values ​​at only two consecutive positions are greater than the set upper limit value at the same time, the timer count will be reset;

[0019] During the timing process, the change of the conductivity probe detection signal is detected. If the exhaust pipe has feed water backflow and the conductivity probe detection value is less than the set upper limit, the timer is reset and the turbine continues to run.

[0020] If the conductivity probe detection value is still at the set upper limit after the timer exceeds the set value, the turbine will be started to shut down the steam inlet, extraction and exhaust, and the turbine will enter the shutdown process.

[0021] As a preferred solution of the protection method for preventing water hammer from occurring in a steam turbine according to the present invention, the operation steps of the DCS control system further include:

[0022] Install conductivity probe on the steam extraction pipeline and set upper and lower limits;

[0023] If the conductivity of the conductivity probe is greater than the set upper limit, and the conductivity detected at two consecutive positions is greater than the set upper limit, the extraction interlock is triggered to close, the turbine is started to shut down, the steam inlet, extraction and exhaust of the turbine are interlocked and closed, and the turbine enters the shutdown process;

[0024] Two interlocking conductivity probes are installed at the inlet and outlet of the shaft seal leakage pipe, and the upper and lower limits of the conductivity are set;

[0025] If the conductivity of the conductivity probe is greater than the set upper limit value, and the conductivity detected at the first position is greater than the set upper limit value and lasts for a period of time, the first conductivity probe interlock is triggered, and the direction of steam entering the steam extraction pipeline from the turbine shaft seal pipeline is determined through logical configuration;

[0026] If the conductivity detected at the first position is greater than the set upper limit and returns to the set lower limit, the steam seal system of the steam turbine is self-sealed through the shaft seal steam supply system. If the conductivity detected at the second position increases, it is confirmed that steam has entered the steam extraction pipeline from the steam turbine shaft seal pipeline, and the steam turbine is started to open the gate, so that the steam inlet, extraction and exhaust of the steam turbine are interlocked and closed, and the steam turbine enters the shutdown process;

[0027] When the conductivity of the conductivity probe is less than the set lower limit, the logic configuration determines that the steam seal system has returned to stability and triggers the second conductivity probe to be interlocked and eliminated. If the conductivity of the conductivity probe is greater than the set upper limit again and is re-triggered, the first judgment is performed again and the cycle continues.

[0028] As a preferred solution of the protection method for preventing water hammer of the steam turbine according to the present invention, the upper limit value of the conductivity of the steam inlet pipe is 1.2 times the maximum conductivity of the normal steam turbine detected by the conductivity probe during the startup and warm-up process, and the lower limit value of the conductivity is set to the conductivity of normal dry steam;

[0029] When the conductivity detected by the conductivity probe of the steam inlet pipe exceeds 1.2 times the maximum conductivity of the normal turbine warm-up when starting, and the signal lasts for more than 3S, the steam inlet pipe interlock of the turbine is triggered, and the DCS trips with a delay time of 3S to 5S.

[0030] The DCS logic configuration determines that the steam inlet pipe conductivity probe detects that the steam inlet pipe conductivity is less than the upper limit of the conductivity probe conductivity again, and the duration is more than 5S, and the delayed tripping interlock is released;

[0031] If the delayed trip interlock is not released within the set time range, the logic configuration adds a interlock flushing procedure, the timer in the DCS is reset to zero, so that the steam conductivity of the steam inlet pipe detected by the steam inlet pipe conductivity probe is greater than the set upper limit again, and the delayed trip interlock procedure is restarted;

[0032] After the DCS timer is reset, the DCS logic configuration is used to delay for 2 seconds. If the conductivity of the steam inlet pipe is detected to be greater than the upper limit of the conductivity probe again, the conductivity probe is flushed and purged 3 to 5 times through the DCS control program, each time lasting 5 to 10 seconds, and the cumulative flushing times are increased by 1. If the steam inlet pipe conductivity probe interlock is continuously triggered after 4 times, the DCS interlock delay trips, otherwise the next step is carried out;

[0033] After the time in the DCS timer expires, if the value detected by the steam inlet pipe conductivity probe is still greater than the upper limit of the conductivity probe, the steam inlet pipe conductivity probe interlock is triggered and the DCS interlock delay trips, otherwise the next step is performed.

[0034] As a preferred solution of the protection method for preventing water hammer of the steam turbine described in the present invention, when the conductivity probe detects that the conductivity is greater than the set upper limit value, the location where the feed water backflow occurs in the exhaust pipe is determined by the logic configuration in the DCS.

[0035] As a preferred solution of the protection method for preventing water hammer of the steam turbine of the present invention, a timer is added to the DCS logic configuration of the steam turbine system. If the conductivity detected by the conductivity probe of the shaft seal system recovers to the set lower limit value again within the time of the timer, it is determined that the normal shaft seal drain leaks into the steam extraction pipeline;

[0036] If the timer is within the timing, and if the conductivity probe detection value is not less than the timer upper limit value, it is determined that the shaft seal is backflowing, the timer is triggered, the turbine is started to open the gate, and the steam inlet, extraction and exhaust of the turbine are interlocked and closed, and the turbine enters the shutdown process.

[0037] In a second aspect, an embodiment of the present invention provides a protection system for preventing water hammer from occurring in a steam turbine, comprising: a conductivity measurement module, a signal processing module, a DCS control system module, and an abnormal interlock processing module;

[0038] The conductivity measurement module is used to measure the conductivity in the steam to determine whether the steam contains water;

[0039] The signal processing module is used to process through a signal converter so that the DCS system can read;

[0040] The DCS control system module is responsible for receiving the signal from the conductivity probe and performing logical judgment according to the preset conductivity upper limit and lower limit;

[0041] The abnormal interlock processing module specifies the interlock processing flow when abnormal conditions occur in the equipment, requiring timely alarm and taking corresponding emergency measures.

[0042] In a third aspect, an embodiment of the present invention provides a computer device, including a memory and a processor, wherein the memory stores a computer program, wherein: when the processor executes the computer program, any step of the above-mentioned protection method for preventing water hammer from occurring in a steam turbine is implemented.

[0043] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein: when the computer program is executed by a processor, any step of the above-mentioned protection method for preventing water hammer from occurring in a steam turbine is implemented.

[0044] The beneficial effects of the present invention are as follows: conductivity measuring points are installed on steam inlet, exhaust steam, shaft seal leakage and other pipelines of the steam turbine. When the steam inlet of the steam turbine carries water, the steam entering the steam turbine is in a wet steam state. At this time, the conductivity is greatly increased compared with the normal dry steam conductivity. Interlocks such as alarms and turbine tripping can be added in the DCS. When feed water backflows into the exhaust steam and shaft seal leakage pipelines, the conductivity in the pipeline increases from the conductivity of dry steam to the conductivity of desalted water. The DCS interlock is used to close the relevant valves and exit the relevant systems until the machine is shut down. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] 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:

[0046] Figure 1 Flowchart of the protection method for preventing water hammer in a steam turbine. DETAILED DESCRIPTION

[0047] In order to make the above-mentioned purposes, 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 drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0048] 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.

[0049] 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.

[0050] The present invention is described in detail with reference to schematic diagrams. When describing the embodiments of the present invention, 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.

[0051] At the same time, in the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper, lower, inner and outer" are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first, second or third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0052] In the present invention, unless otherwise clearly specified and limited, the terms "install, connect, connect" should be understood in a broad sense, for example: it can be a fixed connection, a detachable connection or an integral connection; it can also be a mechanical connection, an electrical connection or a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0053] Example 1

[0054] Reference Figure 1 , which is the first embodiment of the present invention, provides a method for protecting a steam turbine from water hammer, comprising the following steps:

[0055] S1. Install conductivity probes on the steam turbine inlet pipe, steam turbine exhaust pipe, steam extraction and exhaust pipe and shaft seal steam leakage pipe, and set the upper and lower limits of conductivity for each conductivity probe.

[0056] Conductivity is an important indicator for measuring the ion concentration in water or steam. By installing conductivity probes, the conductivity changes of the media (mainly water and steam) in these pipes can be monitored in real time. This is essential to ensure the safe operation of equipment and improve efficiency. High conductivity usually means higher ion concentration, which may cause corrosion or scaling of pipes and equipment, thereby affecting the performance of the turbine. By setting reasonable upper and lower limits of conductivity, once an abnormality is detected, timely measures can be taken to adjust the water quality, thereby effectively preventing these problems from occurring.

[0057] The upper limit of the conductivity probe is the conductivity value of normal dry steam plus the conductivity change of the turbine running with water;

[0058] The lower limit of the conductivity probe is the conductivity value of normal dry steam minus the conductivity change when the turbine is running with water.

[0059] S2. The conductivity signal collected by the conductivity probe is used to determine whether the steam at the corresponding position is in a water-containing state.

[0060] If there is water in the steam, its conductivity will be significantly higher than that of dry steam. Therefore, the conductivity probe can be used to very accurately identify whether there is water in the steam. The conductivity probe can immediately reflect the change of the steam state. When the steam begins to contain water, the probe can respond quickly and provide timely warnings to the operator so that necessary measures can be taken. Unlike some measurement methods that require direct contact with the steam, the conductivity probe can be measured indirectly (such as through the pipe wall), which reduces the impact on the normal operation of the system and also reduces the difficulty of maintenance.

[0061] S3. Interlocking protection is carried out through the DCS control system.

[0062] The operation steps of the DCS control system include:

[0063] When the conductivity probe on the steam inlet pipe of the steam turbine detects that the conductivity is greater than the set upper limit, it will enter the delayed tripping interlock;

[0064] When the conductivity is lower than the set lower limit again, the delayed tripping interlock is eliminated and a timer is added to the control logic;

[0065] After the trip, the timer starts timing. If the steam conductivity of the steam inlet pipe detected by the conductivity probe is greater than the set upper limit again after the timer reaches the set time, the timer is reset and the conductivity probe is flushed, and the timer is cleared;

[0066] The upper and lower limits of the conductivity probe on the exhaust steam pipe are set to 0 in the DCS control system. Multiple conductivity probes are installed on the exhaust steam pipe. If the conductivity detected by the conductivity probe at one position is greater than the set upper limit, it is determined that feed water backflow occurs on the exhaust steam pipe, and the timer is triggered;

[0067] If the detection values ​​of two consecutive conductivity probes are greater than the set upper limit at the same time, and the timer reaches the set time, the turbine will be started to shut down, so that the steam inlet, extraction and exhaust of the turbine will be interlocked and the turbine will enter the shutdown process;

[0068] If the conductivity probe detection values ​​at only two consecutive positions are greater than the set upper limit value at the same time, the timer count will be reset;

[0069] During the timing process, the change of the conductivity probe detection signal is detected. If the exhaust pipe has feed water backflow and the conductivity probe detection value is less than the set upper limit, the timer is reset and the turbine continues to run.

[0070] If the conductivity probe detection value is still at the set upper limit after the timer exceeds the set value, the turbine will be started to shut down the steam inlet, extraction and exhaust, and the turbine will enter the shutdown process.

[0071] The operation steps of the DCS control system also include:

[0072] Install conductivity probe on the steam extraction pipeline and set upper and lower limits;

[0073] If the conductivity of the conductivity probe is greater than the set upper limit, and the conductivity detected at two consecutive positions is greater than the set upper limit, the extraction interlock is triggered to close, the turbine is started to shut down, the steam inlet, extraction and exhaust of the turbine are interlocked and closed, and the turbine enters the shutdown process;

[0074] Two interlocking conductivity probes are installed at the inlet and outlet of the shaft seal leakage pipe, and the upper and lower limits of the conductivity are set;

[0075] If the conductivity of the conductivity probe is greater than the set upper limit value, and the conductivity detected at the first position is greater than the set upper limit value and lasts for a period of time, the first conductivity probe interlock is triggered, and the direction of steam entering the steam extraction pipeline from the turbine shaft seal pipeline is determined through logical configuration;

[0076] If the conductivity detected at the first position is greater than the set upper limit and returns to the set lower limit, the steam seal system of the steam turbine is self-sealed through the shaft seal steam supply system. If the conductivity detected at the second position increases, it is confirmed that steam has entered the steam extraction pipeline from the steam turbine shaft seal pipeline, and the steam turbine is started to open the gate, so that the steam inlet, extraction and exhaust of the steam turbine are interlocked and closed, and the steam turbine enters the shutdown process;

[0077] When the conductivity of the conductivity probe is less than the set lower limit, the logic configuration determines that the steam seal system has returned to stability and triggers the second conductivity probe to be interlocked and eliminated. If the conductivity of the conductivity probe is greater than the set upper limit again and is re-triggered, the first judgment is performed again and the cycle continues.

[0078] 5. The upper limit of the conductivity of the steam inlet pipe is 1.2 times the maximum conductivity of the normal steam turbine detected by the conductivity probe during the startup and warm-up process, and the lower limit of the conductivity is set to the conductivity of normal dry steam;

[0079] When the conductivity detected by the conductivity probe of the steam inlet pipe exceeds 1.2 times the maximum conductivity of the normal turbine warm-up when starting, and the signal lasts for more than 3S, the steam inlet pipe interlock of the turbine is triggered, and the DCS trips with a delay time of 3S to 5S.

[0080] The DCS logic configuration determines that the steam inlet pipe conductivity probe detects that the steam inlet pipe conductivity is less than the upper limit of the conductivity probe conductivity again, and the duration is more than 5S, and the delayed tripping interlock is released;

[0081] If the delayed trip interlock is not released within the set time range, the logic configuration adds a interlock flushing procedure, the timer in the DCS is reset to zero, so that the steam conductivity of the steam inlet pipe detected by the steam inlet pipe conductivity probe is greater than the set upper limit again, and the delayed trip interlock procedure is restarted;

[0082] After the DCS timer is reset, the DCS logic configuration is used to delay for 2 seconds. If the conductivity of the steam inlet pipe is detected to be greater than the upper limit of the conductivity probe again, the conductivity probe is flushed and purged 3 to 5 times through the DCS control program, each time lasting 5 to 10 seconds, and the cumulative flushing times are increased by 1. If the steam inlet pipe conductivity probe interlock is continuously triggered after 4 times, the DCS interlock delay trips, otherwise the next step is carried out;

[0083] After the time in the DCS timer expires, if the value detected by the steam inlet pipe conductivity probe is still greater than the upper limit of the conductivity probe, the steam inlet pipe conductivity probe interlock is triggered and the DCS interlock delay trips, otherwise the next step is performed.

[0084] When the conductivity probe detects that the conductivity is greater than the set upper limit, the logic configuration in the DCS is used to determine the location where the make-up water backflow occurs in the exhaust pipe.

[0085] A timer is added to the DCS logic configuration of the steam turbine system. If the conductivity detected by the conductivity probe of the shaft seal system of the steam turbine system returns to the set lower limit value within the time of the timer, it is determined that the normal shaft seal drain has leaked into the steam extraction pipeline.

[0086] If the timer is within the timing, and if the conductivity probe detection value is not less than the timer upper limit value, it is determined that the shaft seal is backflowing, the timer is triggered, the turbine is started to open the gate, and the steam inlet, extraction and exhaust of the turbine are interlocked and closed, and the turbine enters the shutdown process.

[0087] When the shaft seal system is backflowing, the timer can immediately trigger the protection mechanism, start the turbine brake, ensure that the turbine stops running quickly, and prevent potential safety accidents. The shaft seal backflow may cause steam to enter the shaft seal system, causing equipment overheating, corrosion or other mechanical failures. By shutting down in time, these damages can be effectively avoided and the life of the equipment can be extended. Secondly, by setting the timer, the system can observe the change of conductivity within a certain period of time. If the conductivity returns to the set lower limit before the end of the timer, it means that the shaft seal is drained normally; otherwise, it is judged as shaft seal backflow. This method improves the accuracy of judgment and avoids misjudgment.

[0088] In summary, conductivity measuring points are installed on the turbine steam inlet, exhaust steam, shaft seal leakage and other pipelines. When the turbine steam inlet carries water, the steam entering the turbine is in a wet steam state. At this time, the conductivity is greatly increased compared to the normal dry steam conductivity. In the DCS, alarms, turbine tripping and other interlocks can be added. When feed water backflows into the exhaust steam and shaft seal leakage pipelines, the conductivity in the pipeline increases from the conductivity of dry steam to the conductivity of desalted water. The relevant valves are closed through the DCS interlock to exit the relevant systems until the machine is shut down.

[0089] Example 2

[0090] On the basis of the first embodiment, this embodiment further provides a protection system for preventing water hammer from occurring in a steam turbine, comprising a conductivity measurement module, a signal processing module, a DCS control system module, and an abnormal interlock processing module;

[0091] The conductivity measurement module is used to measure the conductivity in the steam to determine whether the steam contains water;

[0092] The signal processing module is used to process through a signal converter so that the DCS system can read;

[0093] The DCS control system module is responsible for receiving the signal from the conductivity probe and performing logical judgment according to the preset conductivity upper limit and lower limit;

[0094] The abnormal interlock processing module specifies the interlock processing flow when abnormal conditions occur in the equipment, requiring timely alarm and taking corresponding emergency measures.

[0095] This embodiment also provides a computer device, which is suitable for the protection method of preventing water hammer from occurring in a steam turbine, and includes a memory and a processor; the memory is used to store computer executable instructions, and the processor is used to execute computer executable instructions to implement the protection method of preventing water hammer from occurring in a steam turbine as proposed in the above embodiment.

[0096] The computer device may be a terminal, and the computer device includes a processor, a memory, a communication interface, a display screen and an input device connected via a system bus. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be achieved through WIFI, an operator network, NFC (near field communication) or other technologies. The display screen of the computer device may be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device may be a touch layer covering the display screen, or a key, trackball or touchpad provided on the housing of the computer device, or an external keyboard, touchpad or mouse, etc.

[0097] This embodiment also provides a storage medium on which a computer program is stored. When the program is executed by a processor, the protection method for preventing water hammer from occurring in a steam turbine as proposed in the above embodiment is implemented.

[0098] The storage medium proposed in this embodiment and the data storage method proposed in the above embodiment belong to the same inventive concept. The technical details not fully described in this embodiment can be found in the above embodiment, and this embodiment has the same beneficial effects as the above embodiment.

[0099] 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 can 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 present invention.

Claims

1. A method for protecting a steam turbine from water hammer, characterized in that: The following steps are included: Conductivity probes are installed on the steam turbine steam inlet pipe, steam turbine exhaust pipe, steam extraction and exhaust pipe and shaft seal steam leakage pipe, and the upper and lower limits of conductivity are set for each conductivity probe; The conductivity signal collected by the conductivity probe is used to determine whether the steam at the corresponding position is in a water-containing state; Interlocking protection is carried out through the DCS control system.

2. The method for protecting a steam turbine from water hammer as claimed in claim 1, characterized in that: The upper limit of the conductivity probe is the conductivity value of normal dry steam plus the conductivity change of the turbine running with water; The lower limit of the conductivity probe is the conductivity value of normal dry steam minus the conductivity change when the turbine is running with water.

3. The method for protecting a steam turbine from water hammer as claimed in claim 2, characterized in that: The operation steps of the DCS control system include: When the conductivity probe on the steam inlet pipe of the steam turbine detects that the conductivity is greater than the set upper limit, it will enter the delayed tripping interlock; When the conductivity is lower than the set lower limit again, the delayed tripping interlock is eliminated and a timer is added to the control logic; After the trip, the timer starts timing. If the steam conductivity of the steam inlet pipe detected by the conductivity probe is greater than the set upper limit again after the timer reaches the set time, the timer is reset and the conductivity probe is flushed, and the timer is cleared; The upper and lower limits of the conductivity probe on the exhaust steam pipe are set to 0 in the DCS control system. Multiple conductivity probes are installed on the exhaust steam pipe. If the conductivity detected by the conductivity probe at one position is greater than the set upper limit, it is determined that feed water backflow occurs on the exhaust steam pipe, and the timer is triggered; If the detection values ​​of two consecutive conductivity probes are greater than the set upper limit at the same time, and the timer reaches the set time, the turbine will be started to shut down, so that the steam inlet, extraction and exhaust of the turbine will be interlocked and the turbine will enter the shutdown process; If the conductivity probe detection values ​​at only two consecutive positions are greater than the set upper limit value at the same time, the timer count will be reset; During the timing process, the change of the conductivity probe detection signal is detected. If the exhaust pipe has feed water backflow and the conductivity probe detection value is less than the set upper limit, the timer is reset and the turbine continues to run. If the conductivity probe detection value is still at the set upper limit after the timer exceeds the set value, the turbine will be started to shut down the steam inlet, extraction and exhaust, and the turbine will enter the shutdown process.

4. The method for protecting a steam turbine from water hammer as claimed in claim 3, characterized in that: The operation steps of the DCS control system also include: Install conductivity probe on the steam extraction pipeline and set upper and lower limits; If the conductivity of the conductivity probe is greater than the set upper limit, and the conductivity detected at two consecutive positions is greater than the set upper limit, the extraction interlock is triggered to close, the turbine is started to shut down, the steam inlet, extraction and exhaust of the turbine are interlocked and closed, and the turbine enters the shutdown process; Two interlocking conductivity probes are installed at the inlet and outlet of the shaft seal leakage pipe, and the upper and lower limits of the conductivity are set; If the conductivity of the conductivity probe is greater than the set upper limit value, and the conductivity detected at the first position is greater than the set upper limit value and lasts for a period of time, the first conductivity probe interlock is triggered, and the direction of steam entering the steam extraction pipeline from the turbine shaft seal pipeline is determined through logical configuration; If the conductivity detected at the first position is greater than the set upper limit and returns to the set lower limit, the steam seal system of the steam turbine is self-sealed through the shaft seal steam supply system. If the conductivity detected at the second position increases, it is confirmed that steam has entered the steam extraction pipeline from the steam turbine shaft seal pipeline, and the steam turbine is started to open the gate, so that the steam inlet, extraction and exhaust of the steam turbine are interlocked and closed, and the steam turbine enters the shutdown process; When the conductivity of the conductivity probe is less than the set lower limit, the logic configuration determines that the steam seal system has returned to stability and triggers the second conductivity probe to be interlocked and eliminated. If the conductivity of the conductivity probe is greater than the set upper limit again and is re-triggered, the first judgment is performed again and the cycle continues.

5. The method for protecting a steam turbine from water hammer as claimed in claim 4, characterized in that: The upper limit value of the conductivity of the steam inlet pipe is 1.2 times the maximum conductivity of the normal steam turbine detected by the conductivity probe during the startup and warm-up process, and the lower limit value of the conductivity is set to the conductivity of normal dry steam; When the conductivity detected by the conductivity probe of the steam inlet pipe exceeds 1.2 times the maximum conductivity of the normal turbine warm-up when starting, and the signal lasts for more than 3S, the steam inlet pipe interlock of the turbine is triggered, and the DCS trips with a delay time of 3S to 5S. The DCS logic configuration determines that the steam inlet pipe conductivity probe detects that the steam inlet pipe conductivity is less than the upper limit of the conductivity probe conductivity again, and the duration is more than 5S, and the delayed tripping interlock is released; If the delayed trip interlock is not released within the set time range, the logic configuration adds a interlock flushing procedure, the timer in the DCS is reset to zero, so that the steam conductivity of the steam inlet pipe detected by the steam inlet pipe conductivity probe is greater than the set upper limit again, and the delayed trip interlock procedure is restarted; After the DCS timer is reset, the DCS logic configuration is used to delay for 2 seconds. If the conductivity of the steam inlet pipe is detected to be greater than the upper limit of the conductivity probe again, the conductivity probe is flushed and purged 3 to 5 times through the DCS control program, each time lasting 5 to 10 seconds, and the cumulative flushing times are increased by 1. If the steam inlet pipe conductivity probe interlock is continuously triggered after 4 times, the DCS interlock delay trips, otherwise the next step is carried out; After the time in the DCS timer expires, if the value detected by the steam inlet pipe conductivity probe is still greater than the upper limit of the conductivity probe, the steam inlet pipe conductivity probe interlock is triggered and the DCS interlock delay trips, otherwise the next step is performed.

6. The method for protecting a steam turbine from water hammer as claimed in claim 5, characterized in that: When the conductivity probe detects that the conductivity is greater than the set upper limit, the logic configuration in the DCS is used to determine the location where the make-up water backflow occurs in the exhaust pipe.

7. The method for protecting a steam turbine from water hammer as claimed in claim 6, characterized in that: A timer is added to the DCS logic configuration of the steam turbine system. If the conductivity detected by the conductivity probe of the shaft seal system of the steam turbine system returns to the set lower limit value within the time of the timer, it is determined that the normal shaft seal drain has leaked into the steam extraction pipeline. If the timer is within the timing, and if the conductivity probe detection value is not less than the timer upper limit value, it is determined that the shaft seal is backflowing, the timer is triggered, the turbine is started to open the gate, and the steam inlet, extraction and exhaust of the turbine are interlocked and closed, and the turbine enters the shutdown process.

8. A protection system for preventing water hammer in a steam turbine, based on the protection method for preventing water hammer in a steam turbine according to any one of claims 1 to 7, characterized in that: It includes conductivity measurement module, signal processing module, DCS control system module, and abnormal interlocking processing module; The conductivity measurement module is used to measure the conductivity in the steam to determine whether the steam contains water; The signal processing module is used to process through a signal converter so that the DCS system can read; The DCS control system module is responsible for receiving the signal from the conductivity probe and performing logical judgment according to the preset conductivity upper limit and lower limit; The abnormal interlock processing module specifies the interlock processing flow when abnormal conditions occur in the equipment, requiring timely alarm and taking corresponding emergency measures.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method for protecting a steam turbine from water hammer as claimed in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for protecting a steam turbine from water hammer as claimed in any one of claims 1 to 7 are implemented.

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