A nuclear power steam turbine first alarm judgment device and method

Abstract

The present invention discloses a first-out alarm determination device and method for a nuclear power steam turbine. The device comprises at least three redundant fault detection circuits, a first selection module, a second selection module, an AND gate, a first OR gate, and a second OR gate. Each fault detection circuit includes a forward fault detection circuit and a reverse fault detection circuit, and the forward and reverse fault detection circuits of the same fault detection circuit will not fail simultaneously. The AND gate output is configured to issue a first-out alarm signal when faults occur in fault detection circuits in different directions, and only one forward fault detection circuit and only one reverse fault detection circuit simultaneously fail. The device can provide a first-out alarm when fault detection circuits in different directions fail, thereby facilitating the timely investigation of the cause of the accident.

Description

Technical Field

[0001] The present invention relates to the technical field of nuclear power alarm technology, and in particular to a first-out alarm judgment device and method for a nuclear power steam turbine. Background Art

[0002] The first-out alarm of the steam turbine can record the alarm that causes the trip of the steam turbine for the first time. This alarm helps to accurately identify the cause of the turbine trip. When the detection circuit detects a fault signal in the same direction (for example, a high-discharge pressure high-high signal), the corresponding first-out alarm can be triggered through an independent first-out (high-discharge pressure high-high) alarm circuit. However, when the detection circuit detects faults in different directions (for example, the fault signal of one circuit is high and the fault signal of the other circuit is low), the protection circuit can ensure the normal operation of the protection circuit according to the abnormal combination of the high-discharge pressure circuit, but the first-out alarm does not have a corresponding judgment mechanism. In this case, the first-out alarm cannot be triggered, which will interfere with the search for the cause of the accident. Summary of the Invention

[0003] The present invention provides a nuclear power steam turbine first-out alarm judgment device and method, so as to enable the issuance of a first-out alarm when a nuclear power steam turbine fault detection circuit fails in different directions, thereby facilitating the timely investigation of the cause of the accident.

[0004] According to one aspect of the present invention, a first-out alarm determination device for a nuclear power steam turbine is provided. The first-out alarm determination device for a nuclear power steam turbine comprises: at least three redundant fault detection circuits, a first selection module, a second selection module, an AND gate, a first OR gate, and a second OR gate; wherein each of the fault detection circuits is connected to the nuclear power steam turbine; each of the fault detection circuits comprises a forward direction fault detection circuit and a reverse direction fault detection circuit; and the forward direction fault detection circuit and the reverse direction fault detection circuit of the same fault detection circuit will not fail simultaneously;

[0005] Wherein, each of the forward direction fault detection circuits is connected to the input end of the first selection module and the first OR gate input end; each of the reverse direction fault detection circuits is connected to the input end of the second selection module and the second OR gate input end; the first OR gate output end and the second OR gate output end are both connected to the AND gate input end;

[0006] The AND gate output terminal is used to send out a first-out alarm signal when different direction fault detection circuits fail, and only one of the forward direction fault detection circuits fails and only one of the reverse direction fault detection circuits fails.

[0007] Optionally, the nuclear power steam turbine first-out alarm judgment device further includes: a first NOT gate and a second NOT gate; wherein the first NOT gate input end is connected to the output end of the first selection module, and the first NOT gate output end is connected to the AND gate input end; the second NOT gate input end is connected to the output end of the second selection module, and the second NOT gate output end is connected to the AND gate input end;

[0008] The AND gate output terminal is further used to send out a first-out alarm signal when any fault condition occurs except the fault condition where the number of faults occurring in the fault detection circuits in different directions is equal to 2.

[0009] Optionally, the voting mechanism settings of the first selection module and the second selection module are the same.

[0010] Optionally, the voting mechanism settings of the first selection module and the second selection module include one of two out of three and two out of four.

[0011] Optionally, the forward direction fault detection circuit and the reverse direction fault detection circuit are in opposite directions.

[0012] Optionally, the forward direction fault detection circuit is a high-high signal fault detection circuit, and the reverse direction fault detection circuit is a low-low signal fault detection circuit; or, the forward direction fault detection circuit is a low-low signal fault detection circuit, and the reverse direction fault detection circuit is a high-high signal fault detection circuit.

[0013] Optionally, the fault types detected by the fault detection circuit include at least pressure faults and temperature faults of the nuclear power steam turbine.

[0014] Optionally, each redundant fault detection circuit simultaneously detects the same fault type.

[0015] According to another aspect of the present invention, a method for determining the first-out alarm of a nuclear power steam turbine is provided. The method for determining the first-out alarm of a nuclear power steam turbine is applicable to a first-out alarm determining device for a nuclear power steam turbine. The first-out alarm determining device for a nuclear power steam turbine comprises: at least three redundant fault detection circuits, a first selection module, a second selection module, an AND gate, a first OR gate, and a second OR gate; wherein each of the fault detection circuits is connected to the nuclear power steam turbine; each of the fault detection circuits comprises a forward direction fault detection circuit and a reverse direction fault detection circuit; and the forward direction fault detection circuit and the reverse direction fault detection circuit of the same fault detection circuit will not fail at the same time; wherein each of the forward direction fault detection circuits is connected to the input end of the first selection module and the input end of the first OR gate; each of the reverse direction fault detection circuits is connected to the input end of the second selection module and the input end of the second OR gate; the output end of the first OR gate and the output end of the second OR gate are both connected to the input end of the AND gate;

[0016] The method comprises:

[0017] When faults occur in the fault detection circuits in different directions, and only one of the forward direction fault detection circuits fails and only one of the reverse direction fault detection circuits fails, a first alarm signal is issued.

[0018] Optionally, the nuclear power steam turbine first-out alarm judgment device further includes: a first NOT gate and a second NOT gate; wherein the first NOT gate input end is connected to the output end of the first selection module, and the first NOT gate output end is connected to the AND gate input end; the second NOT gate input end is connected to the output end of the second selection module, and the second NOT gate output end is connected to the AND gate input end;

[0019] The method further comprises:

[0020] When any fault condition occurs except the fault condition where the number of fault detection circuits in different directions that are faulty is equal to 2, a first-out alarm signal is issued.

[0021] The technical solution of the embodiment of the present invention provides a first-out alarm judgment device and method for a nuclear power steam turbine, wherein the first-out alarm judgment device for a nuclear power steam turbine includes: at least three redundant fault detection circuits, a first selection module, a second selection module, an AND gate, a first OR gate and a second OR gate; wherein each fault detection circuit is connected to the nuclear power steam turbine; each fault detection circuit includes a forward direction fault detection circuit and a reverse direction fault detection circuit; and the forward direction fault detection circuit and the reverse direction fault detection circuit of the same fault detection circuit will not fail at the same time; wherein each forward direction fault detection circuit is connected to the input end of the first selection module and the first OR gate input end; each reverse direction fault detection circuit is connected to the input end of the second selection module and the second OR gate input end; the first OR gate output end and the second OR gate output end are both connected to the AND gate input end; the AND gate output end is used to send a first-out alarm signal when faults occur in fault detection circuits in different directions, and only one forward direction fault detection circuit fails and only one reverse direction fault detection circuit fails at the same time. It can be seen from this that this device can not only realize the first-out alarm of the nuclear power steam turbine when an abnormal situation occurs in the same direction, but also realize the first-out alarm when its fault detection circuit fails in different directions, that is, when only one positive direction fault detection circuit fails and at the same time only one reverse direction fault detection circuit fails, a first-out alarm signal is issued, which is conducive to the timely investigation of the cause of the accident.

[0022] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present invention, nor is it intended to limit the scope of the present invention. Other features of the present invention will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of 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.

[0024] Figure 1 This is a logic diagram of the protection of the high-pressure cylinder exhaust pressure of a steam turbine using a protection cabinet as an example in the prior art;

[0025] Figure 2 It is a first-out alarm logic diagram in the prior art;

[0026] Figure 3 It is another first-out alarm logic diagram in the prior art;

[0027] Figure 4 It is another first-out alarm logic diagram in the prior art;

[0028] Figure 5 This is a schematic diagram of the principle structure of a nuclear power steam turbine first-out alarm judgment device provided in an embodiment of the present invention;

[0029] Figure 6 This is a structural diagram of a nuclear power steam turbine first-out alarm determination device using a two-out-of-four voting mechanism as an example provided in an embodiment of the present invention;

[0030] Figure 7 This is a schematic diagram of the principle structure of another nuclear power steam turbine first-out alarm judgment device provided in an embodiment of the present invention;

[0031] Figure 8 This is a structural diagram of another nuclear power steam turbine first-out alarm judgment device provided in an embodiment of the present invention, taking a two-out-of-four voting method as an example. DETAILED DESCRIPTION

[0032] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0033] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0034] The inventors have found through research that the protection system composed of multiple sensors, multiple signal processing units and multiple actuators often adopts software and hardware circuits such as "three out of two" and "four out of two" to complete the protection function. This can prevent the protection system from malfunctioning due to a single fault, so as to improve the reliability of the protection system. The detection circuit composed of sensors and signal processing units (hereinafter referred to as the detection circuit) is usually designed according to the requirements of the process system. For example, the detection circuit detects a high-high (or low-low) pressure "four out of two" circuit. When two or more detection circuits detect a high-high (or low-low) pressure signal, the protection system is activated. The high-high (or low-low) pressure signal detected by the detection circuit can be the result of the normal operation detection of the detection circuit, or it can be triggered by a detection circuit failure.

[0035] For example, a nuclear power plant steam turbine uses a two-out-of-four logic system for high-pressure cylinder exhaust pressure (HPEP) tripping. Four HPEP transmitters on-site send signals to four turbine protection cabinets. After signal processing, these signals are converted into high-high and low-low switching signals. These two signals (in an "OR" relationship) are collectively referred to as the HPEP abnormal shutdown. In addition to being combined with the HPEP abnormal shutdown signals sent by the other three protection cabinets to form a two-out-of-four logic judgment, they are also sent to the other three protection cabinets for two-out-of-four logic judgment to generate their own HPEP shutdown signals. This approach saves approximately half the software and hardware resources compared to using completely independent HPEP high-high and low-low shutdown circuits. The four protection cabinets output the HPEP abnormal shutdown signals to the shutdown solenoid valve, completing the turbine trip. The turbine first-out alarm records the alarm that triggered the first turbine trip, which helps accurately identify the cause of the turbine trip. The first-out alarm should accurately report whether the high-exhaust pressure is high-high or low-low, which is helpful to identify the cause. Therefore, two independent first-out high-high and low-low alarm circuits are designed.

[0036] Figure 1 This is a logic diagram of the protection of the high-pressure cylinder exhaust pressure of a steam turbine using a protection cabinet as an example in the prior art. Figure 2This is a first alarm logic diagram in the prior art. Figure 3 This is another first alarm logic diagram in the prior art. Figure 4 This is another first alarm logic diagram in the prior art. Figures 1 to 4 The symbols in the code are as follows: Trip Demand: turbine trip command, HPT: turbine high pressure cylinder exhaust pressure, HH: high high alarm, LL: low low alarm, - number: circuit identification, First Out: alarm first out. Figures 1 to 4 ,refer to Figure 1 , after taking the threshold value, the No. 1 high-pressure transmitter generates high-pressure high-high-1 (HPT Pre.HH-1) and high-pressure low-low-1 (HPTPre.LL-1). The two signals are "OR" logically to form the high-pressure abnormal trip signal-1 (HPT Pre.AbnormalTrip-1) of circuit 1, and the other three circuits are combined to form HPT Abnormal Trip-1 after taking two out of four and sent to Figure 2 , Figure 1 HPTPre.HH-1 or HPT Pre.LL-1 in the output are respectively combined with the signal after taking two out of four through the "AND" logic to form the signal HPT HH-1 or HPT LL-1 and sent to Figure 3 . Figure 2 HPT Abnormal Trip-1 is composed of other protection circuits. After passing through the delay module T2, it forms the Trip Demand-1 signal and is sent to Figure 3 .

[0037] Figure 2 The Trip Demand-1 signal sent to Figure 3 , after the "not" logic, Figure 1 The incoming signal HPTHH-1 or HPT LL-1 is sent to the S end of the RS trigger after the "AND" logic, and the signal after the "NOT" logic is sent to the R end of the RS trigger after the pulse. The output terminal Q of the RS trigger outputs the signal HPT HH (First out) -1 and HPT LL (First out) -1, which is used to trigger the first-out alarm signal HPT HH (First out) -1 or HPT LL (First out) -1. The output signal is sent to Figure 4 This logic ensures that only the high-pressure high-high and low-pressure low-low first-out alarms are sent, without interference from other alarms. The signal after the "not" logic is pulsed and sent to the R terminal of the RS trigger. When the Trip Demand-1 signal disappears, the first-out alarm signal can be reset. Figure 3 The HPT HH (First out)-1 and HPT LL (First out)-1 signals are sent to Figure 4 , Figure 4 The HPT HH (First out)-1 or HPT LL (First out)-1 signal is respectively combined with the other three signals to output HPT HH-Trip First out or HPT LL-Trip First out after selecting two out of four. These two alarm signals are the first-out alarm signals finally issued and are used to improve the operation of operating personnel and for accident analysis.

[0038] Based on the above logical judgment, the detection circuit can effectively determine the high-discharge pressure high-high and low-low first-out alarms. However, if the detection circuits in different directions fail, although the protection circuit can effectively perform its protection function, the failure of the detection circuits in different directions will not trigger any first-out alarms, which makes accident analysis difficult. That is, when the detection circuit detects a fault signal in the same direction (for example, a high-discharge pressure high-high signal), the corresponding first-out alarm can be triggered through an independent first-out (high-discharge pressure high-high) alarm circuit. However, when the detection circuits detect faults in different directions (for example, a high fault signal in one circuit and a low fault signal in another circuit), the protection circuit can ensure the normal operation of the protection circuit according to the abnormal high-discharge pressure combination circuit, but the first-out alarm lacks a corresponding judgment mechanism. In this case, the four-out-two first-out alarm cannot be triggered. Furthermore, when two or more detection circuits fail, the existing first-out alarm circuit will generate two alarms, which cannot achieve the first-out alarm effect. Therefore, it is necessary to design the first-out alarm of nuclear power steam turbines.

[0039] To this end, an embodiment of the present invention provides a nuclear power steam turbine first-out alarm judgment device and method, so as to enable the issuance of a first-out alarm when a nuclear power steam turbine fault detection circuit fails in different directions, which is conducive to timely investigation of the cause of the accident.

[0040] Figure 5 This is a schematic diagram of the principle structure of a nuclear power steam turbine first alarm judgment device provided in an embodiment of the present invention. Figure 5The nuclear power steam turbine first-out alarm judgment device includes: at least three redundant fault detection circuits, a first selection module 10, a second selection module 20, an AND gate 30, a first OR gate 40 and a second OR gate 50; wherein each fault detection circuit is connected to the nuclear power steam turbine; each fault detection circuit includes a forward direction fault detection circuit and a reverse direction fault detection circuit; and the forward direction fault detection circuit and the reverse direction fault detection circuit of the same fault detection circuit will not fail at the same time; wherein each forward direction fault detection circuit is connected to the input end of the first selection module 10 and the input end of the first OR gate 40; each reverse direction fault detection circuit is connected to the input end of the second selection module 20 and the input end of the second OR gate 50; the output end of the first OR gate 40 and the output end of the second OR gate 50 are both connected to the input end of the AND gate 30; the output end of the AND gate 30 is used to send a first-out alarm signal when faults occur in fault detection circuits in different directions, and only one forward direction fault detection circuit fails and only one reverse direction fault detection circuit fails at the same time.

[0041] For example, take the redundant setting of three fault detection loops as an example, refer to Figure 5 , which are respectively the first fault detection circuit 100, the second fault detection circuit 200 and the third fault detection circuit 300. The first fault detection circuit 100, the second fault detection circuit 200 and the third fault detection circuit 300 are all connected to the nuclear power steam turbine (not shown).

[0042] Each fault detection circuit includes a forward fault detection circuit and a reverse fault detection circuit, and the forward and reverse fault detection circuits of the same fault detection circuit will not fail simultaneously. For example, the first fault detection circuit 100 includes a forward fault detection circuit 101 of the first fault detection circuit and a reverse fault detection circuit 102 of the first fault detection circuit, and the forward fault detection circuit 101 of the first fault detection circuit and the reverse fault detection circuit 102 of the first fault detection circuit will not fail simultaneously. The second fault detection circuit 200 includes a forward fault detection circuit 201 of the second fault detection circuit and a reverse fault detection circuit 202 of the second fault detection circuit, and the forward fault detection circuit 201 of the second fault detection circuit and the reverse fault detection circuit 202 of the second fault detection circuit will not fail simultaneously. The third fault detection circuit 300 includes a forward direction fault detection circuit 301 and a reverse direction fault detection circuit 302 of the third fault detection circuit, and the forward direction fault detection circuit 301 and the reverse direction fault detection circuit 302 of the third fault detection circuit will not fail at the same time.

[0043] Each forward fault detection circuit is connected to the input of the first selection module 10 and the input of the first OR gate 40; each reverse fault detection circuit is connected to the input of the second selection module 20 and the input of the second OR gate 50; and the outputs of the first OR gate 40 and the second OR gate 50 are both connected to the input of the AND gate 30. For example, the forward fault detection circuit 101 of the first fault detection circuit, the forward fault detection circuit 201 of the second fault detection circuit, and the forward fault detection circuit 301 of the third fault detection circuit are connected to the input of the first selection module 10 and the input of the first OR gate 40. The reverse fault detection circuit 102 of the first fault detection circuit, the reverse fault detection circuit 202 of the second fault detection circuit, and the reverse fault detection circuit 302 of the third fault detection circuit are all connected to the input of the second selection module 20 and the input of the second OR gate 50.

[0044] The first selection module 10 and the second selection module 20 can employ a voting mechanism such as a two-out-of-three or a two-out-of-four voting mechanism. The number of redundant fault detection loops is related to the number of voting mechanisms. For example, when the selection module employs a two-out-of-three voting mechanism, three redundant fault detection loops are configured; when the selection module employs a two-out-of-four voting mechanism, four redundant fault detection loops are configured.

[0045] In the technical solution of this embodiment, the nuclear power steam turbine first-out alarm judgment device provided by the embodiment of the present invention can realize the first-out alarm when only the same-direction fault detection circuit fails under normal circumstances, and can also realize the first-out alarm when fault detection circuits in different directions fail under abnormal circumstances, and only one forward-direction fault detection circuit fails and only one reverse-direction fault detection circuit fails at the same time. Among them, the first-out alarm under normal circumstances means: for example, when at least one forward-direction fault detection circuit fails and none of the reverse-direction fault detection circuits fail, according to the three-out-two voting mechanism, when two or more forward-direction fault detection circuits fail, a first-out alarm signal can be issued by the first selection module 10. For example, let fault occurrence be 1 and no fault occurrence be 0, let the fault conditions of the forward direction fault detection circuit 101 of the first fault detection circuit, the forward direction fault detection circuit 201 of the second fault detection circuit, and the forward direction fault detection circuit 301 of the third fault detection circuit be 1, 0, 1, and the fault conditions of the reverse direction fault detection circuit 102 of the first fault detection circuit, the reverse direction fault detection circuit 202 of the second fault detection circuit, and the reverse direction fault detection circuit 302 of the third fault detection circuit be 0, 0, 0, then the output of the first selection module 10 is 1 to issue a first-out alarm, and the outputs of the second selection module 20 and the AND gate 30 are both 0 and no first-out alarm is issued. Conversely, when at least one reverse direction fault detection circuit fails and none of the forward direction fault detection circuits fails, the principle is the same and will not be repeated here.

[0046] It should be noted that under normal circumstances, the first-out alarm when only the same-direction fault detection circuit fails is a normal fault alarm for the nuclear power steam turbine process system. However, when fault detection circuits in different directions fail, and only one forward-direction fault detection circuit fails, and only one reverse-direction fault detection circuit fails, the first-out alarm refers to a detection circuit failure.

[0047] The first-out alarm in an abnormal situation refers to the situation when fault detection circuits in different directions fail, only one forward fault detection circuit fails, and only one reverse fault detection circuit fails. For example, a two-out-of-three voting mechanism is used, with a fault value of 1 and no fault value of 0. When only one of the forward direction fault detection circuit 101 of the first fault detection circuit, the forward direction fault detection circuit 201 of the second fault detection circuit, and the forward direction fault detection circuit 301 of the third fault detection circuit fails (such as 1, 0, 0), and only one of the reverse direction fault detection circuit 102 of the first fault detection circuit, the reverse direction fault detection circuit 202 of the second fault detection circuit, and the reverse direction fault detection circuit 302 of the third fault detection circuit fails (such as 0, 1, 0, and the forward direction fault detection circuit and the reverse direction fault detection circuit of the same fault detection circuit will not fail at the same time), according to the three-out-of-two voting mechanism, the output of the first selection module 10 and the second selection module 20 is 0 and no alarm will be issued, the output of the first OR gate 40 and the second OR gate 50 are both 1, then the output of the AND gate 30 is 1, and the output end of the AND gate 30 sends a first-out alarm signal.

[0048] The technical solution of this embodiment provides a first-out alarm judgment device for a nuclear power steam turbine, which includes: at least three redundant fault detection circuits, a first selection module, a second selection module, an AND gate, a first OR gate, and a second OR gate; wherein each fault detection circuit is connected to the nuclear power steam turbine; each fault detection circuit includes a forward direction fault detection circuit and a reverse direction fault detection circuit; and the forward direction fault detection circuit and the reverse direction fault detection circuit of the same fault detection circuit will not fail at the same time; wherein each forward direction fault detection circuit is connected to the input end of the first selection module and the first OR gate input end; each reverse direction fault detection circuit is connected to the input end of the second selection module and the second OR gate input end; the first OR gate output end and the second OR gate output end are both connected to the AND gate input end; the AND gate output end is used to send a first-out alarm signal when faults occur in fault detection circuits in different directions, and only one forward direction fault detection circuit fails and only one reverse direction fault detection circuit fails at the same time. It can be seen from this that this device can not only realize the first-out alarm of the nuclear power steam turbine when an abnormal situation occurs in the same direction, but also realize the first-out alarm when faults occur in different directions in its fault detection circuit, that is, when only one positive direction fault detection circuit fails and at the same time only one reverse direction fault detection circuit fails, a first-out alarm signal is issued, which is conducive to the timely investigation of the cause of the accident and avoids affecting the normal operation of the nuclear power system.

[0049] On the basis of the above-mentioned technical implementation scheme, optionally, the voting mechanism of the first selection module and the second selection module are set to be the same.

[0050] Since each fault detection loop includes a forward direction fault detection loop and a reverse direction fault detection loop, the voting mechanism settings of the first selection module and the second selection module are the same.

[0051] Optionally, the voting mechanism settings of the first selection module and the second selection module include one of two out of three and two out of four.

[0052] The two-out-of-three and two-out-of-four voting schemes are related to the number of redundant fault detection circuits actually configured in the nuclear power turbine. For example, when the selection module uses a two-out-of-three voting mechanism, three fault detection circuits are configured for redundancy; when the selection module uses a two-out-of-four voting mechanism, four fault detection circuits are configured for redundancy. Therefore, the voting mechanism settings for the first and second selection modules can be customized based on actual circumstances and are not specifically limited here.

[0053] In addition, the voting mechanism can also be set to other forms of voting mechanisms, which can be set specifically according to actual conditions and are not specifically limited here.

[0054] Optionally, the forward direction fault detection loop and the reverse direction fault detection loop are in opposite directions.

[0055] The forward direction fault detection circuit and the reverse direction fault detection circuit in the same fault detection circuit will not fail at the same time.

[0056] Optionally, the forward direction fault detection circuit is a high-high signal fault detection circuit, and the reverse direction fault detection circuit is a low-low signal fault detection circuit; or, the forward direction fault detection circuit is a low-low signal fault detection circuit, and the reverse direction fault detection circuit is a high-high signal fault detection circuit.

[0057] It should be noted that whether the forward direction fault detection circuit is a high-high signal or the reverse direction fault detection circuit is a high-high signal can be set according to actual conditions and is not specifically limited here.

[0058] Optionally, the fault types detected by the fault detection circuit include at least pressure faults and temperature faults of the nuclear power steam turbine.

[0059] Among them, nuclear power steam turbine failures may occur due to pressure failures, temperature failures, etc. Therefore, the fault detection circuit connected to the nuclear power steam turbine can be used to detect pressure failures, temperature failures, etc. Therefore, the fault types detected by the fault detection circuit include at least pressure failures and temperature failures of the nuclear power steam turbine.

[0060] Optionally, each redundant fault detection circuit simultaneously detects the same fault type.

[0061] For example, Figure 5 The first fault detection circuit 100, the second fault detection circuit 200 and the third fault detection circuit 300 detect the same fault type at the same time or in the same detection state. For example, they all detect the high-pressure discharge signal of the nuclear power steam turbine or the temperature signal of the nuclear power steam turbine.

[0062] Figure 6 This is a schematic diagram of the structure of a nuclear power steam turbine first alarm judgment device provided in an embodiment of the present invention, taking a four-out-two voting mechanism as an example. For example, the high-pressure exhaust cylinder pressure protection of a nuclear power steam turbine is taken as an example, and the four-out-two voting mechanism is used as an example for explanation. Figure 6 ,The first selection module and the second selection module both adopt a four-out-of-two voting mechanism. ,The nuclear power steam turbine high pressure exhaust cylinder pressure protection redundancy sets four pressure fault detection ,circuits. Each pressure fault detection circuit includes a high-high direction pressure fault detection ,circuits and a low-low direction pressure fault detection ,circuits. Figure 6 Left side HPTHH (First out)-1 to HPT HH (First out)-4, Figure 6HPT LL (First out) -1 to HPT LL (First out) -4 on the right. Among them, HPT HH (First out) -1 to HPT HH (First out) -4 represent the high-high signal first-out alarm signals of the 1-4 detection circuits of the high-pressure cylinder exhaust pressure of the turbine, and HPT LL (First out) -1 to HPT LL (First out) -4 represent the low-low signal first-out alarm signals of the 1-4 detection circuits of the high-pressure cylinder exhaust pressure of the turbine. Specifically, let 1 be the occurrence of a fault and 0 be no fault. Assuming that the fault conditions of HPT HH (First out) -1 to HPT HH (First out) -4 on the left are 1, 0, 0, 0, and the fault conditions of HPT LL (First out) -1 to HPT LL (First out) -4 on the right are 0, 0, 1, 0, then Figure 6 The outputs of the left four-out-of-two and the right four-out-of-two are both 0 and no first alarm is issued. The outputs of the left OR gate and the right OR gate are both 1, then the output of the AND gate is 1, and the AND gate issues a first alarm signal.

[0063] according to Figure 5 and Figure 6 The provided implementation scheme can achieve the first-out alarm effect when different direction fault detection circuits fail, and only one forward direction fault detection circuit fails and only one reverse direction fault detection circuit fails at the same time. However, when the number of fault detection circuits in different directions that fail is equal to 2, and any fault condition other than only one forward direction fault detection circuit fails and only one reverse direction fault detection circuit fails at the same time, then Figure 5 and Figure 6 The implementation scheme provided will not achieve the effect of first-out alarm.

[0064] For example, reference Figure 6 , assuming that the fault conditions of HPT HH(First out)-1 to HPT HH(First out)-4 on the left are 1, 0, 0, 0, and the fault conditions of HPT LL(First out)-1 to HPT LL(First out)-4 on the right are 1, 0, 1, 0, then Figure 6 The output of the left-side four-out-of-two is 0 and will not be the first alarm, while the output of the right-side four-out-of-two is both 1 and will be the first alarm. The outputs of the left-side OR gate and the right-side OR gate are both 1, then the output of the AND gate is 1, so the AND gate and the right-side four-out-of-two will both send out the first alarm signal, which loses the meaning of the first alarm and interferes with fault analysis.

[0065] On the other hand, if two or more detection circuits fail, a high discharge pressure high signal is detected. Figure 4 Logic, high high four take two logic can first trigger HPT HH-Trip First out; Figure 1 In the logic, the high pressure high signal is detected to trigger HPT Abnormal Trip-1, which is transmitted to Figure 2 After that, the signal Trip Demand-1 is formed; Figure 1 The logic also triggers HPT HH-1 to pass to Figure 3 , together with the Trip Demand-1 signal, forms Figure 3 The high exhaust pressure high first out logic on the left triggers HPT HH (First out)-1. HPT HH (First out)-1 and another alarm with the same principle (such as HPT HH (First out)-2) are connected through Figure 6 The left logic selects two out of four and issues HPT HH-Trip First out. After the turbine is shut down due to faults in two or more detection circuits, the turbine steam inlet valve cuts off the steam source and the high-discharge pressure decreases. At this time, the high-high signal mistakenly sent by the high-discharge pressure sensor may disappear (the sensor's force-bearing element may recover or partially recover after the pressure on the pressure side disappears, and the corresponding signal disappears). Figure 3 The logic shows that when Trip Demand-1 disappears and the turbine is shut down, the high exhaust steam pressure will decrease, triggering the high exhaust pressure low signal. Figure 3 On the right side of the logic, the Trip Demand-1 disappearance signal is negated and set to true, and then the high pressure low signal is ANDed to trigger HPT LL (First out)-1; Figure 6 The same alarm logic as other detection circuits (such as HPT LL (First out) - 2) generates HPT LL-Trip First out through a two-out-of-four selection process. Therefore, the high-exhaust pressure high-high first-out alarm HPT HH-Trip First out will appear first, followed by the high-exhaust pressure low-low alarm HPT LL-Trip First out. The low-low alarm should not appear and its appearance will mislead fault analysis.

[0066] Therefore, the embodiment of the present invention can solve this problem through the following solution based on the above implementation scheme.

[0067] Figure 7 This is a schematic diagram of the principle structure of another nuclear power steam turbine first alarm judgment device provided in an embodiment of the present invention. Figure 7The nuclear power steam turbine first-out alarm judgment device also includes: a first NOT gate 60 and a second NOT gate 70; wherein, the input end of the first NOT gate 60 is connected to the output end of the first selection module 10, and the output end of the first NOT gate 60 is connected to the input end of the AND gate 30; the input end of the second NOT gate 70 is connected to the output end of the second selection module 20, and the output end of the second NOT gate 70 is connected to the input end of the AND gate 30; the output end of the AND gate 30 is also used to issue a first-out alarm signal when any fault condition occurs, except for the fault condition in which the number of faults in the fault detection circuits in different directions is equal to 2.

[0068] Among them, any fault condition other than the fault condition in which the number of fault detection circuits in different directions is equal to 2 can be, for example, that fault detection circuits in different directions fail, and the number of fault detection circuits in different directions is not equal to 2 at the same time. Figure 7 , take the three-out-of-two voting mechanism as an example, and assume that a fault occurs as 1 and no fault occurs as 0. For example, assuming that the fault conditions of the forward direction fault detection circuit 101 of the first fault detection circuit, the forward direction fault detection circuit 201 of the second fault detection circuit, and the forward direction fault detection circuit 301 of the third fault detection circuit are 1, 0, and 1, respectively, and the fault conditions of the reverse direction fault detection circuit 102 of the first fault detection circuit, the reverse direction fault detection circuit 202 of the second fault detection circuit, and the reverse direction fault detection circuit 302 of the third fault detection circuit are 0, 1, and 0, respectively (the forward direction fault detection circuit and the reverse direction fault detection circuit of the same fault detection circuit will not fail at the same time), then the first selection module 10 outputs 1 and sends a first-out alarm signal, the first OR gate 40 outputs 1, and the first selection module 1 0 outputs 1 and then outputs 0 to the input of the AND gate 30 after passing through the first NOT gate 60; the second selection module 20 outputs 0 and will not issue a first-out alarm signal, the second OR gate 50 outputs 1, and the second selection module 20 outputs 0 and then outputs 1 to the input of the AND gate 30 after passing through the second NOT gate 70, so that the output of the AND gate 30 is 0 and will not issue a first-out alarm signal, so only the first selection module 10 will issue a first-out alarm signal, thereby achieving the first-out alarm effect when the fault detection circuit fails in different directions and the number of faults in the detection circuits in any direction is greater than or equal to 2 (that is, except for the fault conditions where only one positive direction fault detection circuit fails and at the same time only one reverse direction fault detection circuit fails).

[0069] For another example, assuming that the fault conditions of the forward direction fault detection circuit 101 of the first fault detection circuit, the forward direction fault detection circuit 201 of the second fault detection circuit, and the forward direction fault detection circuit 301 of the third fault detection circuit are 0, 0, and 1 respectively, and the fault conditions of the reverse direction fault detection circuit 102 of the first fault detection circuit, the reverse direction fault detection circuit 202 of the second fault detection circuit, and the reverse direction fault detection circuit 302 of the third fault detection circuit are 1, 1, and 0 respectively (the forward direction fault detection circuit and the reverse direction fault detection circuit of the same fault detection circuit will not fail at the same time), then the output of the first selection module 10 is 0 and no signal is issued. For the first-out alarm signal, the output of the first OR gate 40 is 1, and the first selection module 10 outputs 0 and then outputs 1 to the input of the AND gate 30 after passing through the first NOT gate 60; the output of the second selection module 20 is 1 and a first-out alarm signal is issued, the output of the second OR gate 50 is 1, and the output of the second selection module 20 is 1 and then outputs 0 to the input of the AND gate 30 after passing through the second NOT gate 70, so that the output of the AND gate 30 is 0 and no first-out alarm signal is issued, so only the second selection module 20 will issue a first-out alarm signal, thereby achieving the first-out alarm effect of the fault detection circuit in any fault situation except the fault situation where the number of faults in the fault detection circuits in different directions is equal to 2.

[0070] Figure 8 This is a schematic diagram of the structure of another nuclear power steam turbine first alarm judgment device provided in an embodiment of the present invention, which takes a four-out-two voting method as an example. For example, the high-pressure exhaust cylinder pressure protection of a nuclear power steam turbine is taken as an example, and the four-out-two voting mechanism is used as an example for explanation. Figure 8 ,The first selection module and the second selection module both adopt a four-out-of-two voting mechanism. ,The nuclear power steam turbine high pressure exhaust cylinder pressure protection redundancy sets four pressure fault detection ,circuits. Each pressure fault detection circuit includes a high-high direction pressure fault detection ,circuits and a low-low direction pressure fault detection ,circuits. Figure 8 Left side HPT HH (First out)-1 to HPT HH (First out)-4, Figure 8HPT LL (First out) -1 to HPT LL (First out) -4 on the right. Among them, HPT HH (First out) -1 to HPT HH (First out) -4 represent the high-high signal first-out alarm signals of the 1-4 detection circuits of the high-pressure cylinder exhaust pressure of the turbine, and HPT LL (First out) -1 to HPT LL (First out) -4 represent the low-low signal first-out alarm signals of the 1-4 detection circuits of the high-pressure cylinder exhaust pressure of the turbine. Specifically, let 1 be the occurrence of a fault and 0 be the absence of a fault. For example, assuming that the fault conditions of HPT HH (First out) -1 to HPT HH (First out) -4 on the left are 1, 0, 1, 0, and the fault conditions of HPT LL (First out) -1 to HPT LL (First out) -4 on the right are 0, 1, 0, 0, then Figure 8 The output of the left four-out-of-two is 1 and a first-out alarm signal will be issued, the output of the right four-out-two is 0 and no first-out alarm will be issued, and the output of the left four-out-two is 1 and outputs 0 to the AND gate via the left NOT gate, and the output of the right four-out-two is 0 and outputs 1 to the AND gate via the right NOT gate, and the outputs of the left OR gate and the right OR gate are both 1, then the output of the AND gate is 0, so that the AND gate will not issue a first-out alarm signal, and only the left four-out-two will issue a first-out alarm signal, thereby achieving the first-out alarm effect of the fault detection circuit in any fault situation except the fault situation where the number of faults in the fault detection circuits in different directions is equal to 2.

[0071] An embodiment of the present invention also provides a method for determining a first-out alarm of a nuclear power steam turbine. The method is applicable to a first-out alarm determination device for a nuclear power steam turbine, which includes at least three redundant fault detection circuits, a first selection module, a second selection module, an AND gate, a first OR gate, and a second OR gate. Each fault detection circuit is connected to the nuclear power steam turbine. Each fault detection circuit includes a forward fault detection circuit and a reverse fault detection circuit. The forward fault detection circuit and the reverse fault detection circuit of the same fault detection circuit will not fail simultaneously. Each forward fault detection circuit is connected to the input of the first selection module and the input of the first OR gate. Each reverse fault detection circuit is connected to the input of the second selection module and the input of the second OR gate. The output of the first OR gate and the output of the second OR gate are both connected to the input of the AND gate.

[0072] The method comprises: sending a first-out alarm signal when faults occur in different direction fault detection circuits, and only one forward direction fault detection circuit fails and only one reverse direction fault detection circuit fails at the same time.

[0073] The technical solution of this embodiment provides a method for determining a first-out alarm for a nuclear power steam turbine. The method includes: issuing a first-out alarm signal when faults occur in different-direction fault detection circuits, only one forward-direction fault detection circuit fails, and only one reverse-direction fault detection circuit fails simultaneously. As can be seen, this method not only enables a first-out alarm for a nuclear power steam turbine when a same-direction abnormality occurs, but also enables a first-out alarm for faults in different directions within the fault detection circuits. Specifically, it issues a first-out alarm signal when only one forward-direction fault detection circuit fails and only one reverse-direction fault detection circuit fails simultaneously. This facilitates the timely investigation of the cause of the accident and avoids affecting the normal operation of the nuclear power system.

[0074] Optionally, the nuclear power steam turbine first-out alarm judgment device further includes: a first NOT gate and a second NOT gate; wherein the first NOT gate input end is connected to the output end of the first selection module, and the first NOT gate output end is connected to the AND gate input end; the second NOT gate input end is connected to the output end of the second selection module, and the second NOT gate output end is connected to the AND gate input end;

[0075] The method further includes: issuing a first-out alarm signal when any fault condition occurs except the fault condition in which the number of fault detection circuits in different directions that have faults is equal to 2.

[0076] It should be understood that the various forms of the processes shown above can be used to reorder, add, or delete steps. For example, the steps described in the present invention can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution of the present invention can be achieved. This is not limited herein.

[0077] The above specific embodiments do not limit the scope of protection of the present invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A nuclear power steam turbine first alarm judgment device, characterized in that: include: At least three redundant fault detection circuits, a first selection module, a second selection module, an AND gate, a first OR gate, and a second OR gate; wherein each of the fault detection circuits is connected to the nuclear power steam turbine; each of the fault detection circuits includes a forward direction fault detection circuit and a reverse direction fault detection circuit; and the forward direction fault detection circuit and the reverse direction fault detection circuit of the same fault detection circuit will not fail at the same time; Each of the forward fault detection circuits is connected to the input of the first selection module and the input of the first OR gate; each of the reverse fault detection circuits is connected to the input of the second selection module and the input of the second OR gate; the output of the first OR gate and the output of the second OR gate are both connected to the input of the AND gate; and the voting mechanism of the first selection module and the second selection module includes one of two out of three and two out of four. The AND gate output terminal is used to send out a first-out alarm signal when different direction fault detection circuits fail, and only one of the forward direction fault detection circuits fails and only one of the reverse direction fault detection circuits fails.

2. The nuclear power steam turbine first-out alarm judgment device according to claim 1, characterized in that: The invention also includes: a first NOT gate and a second NOT gate; wherein the first NOT gate input is connected to the output of the first selection module, and the first NOT gate output is connected to the AND gate input; the second NOT gate input is connected to the output of the second selection module, and the second NOT gate output is connected to the AND gate input; The AND gate output terminal is further used to send out a first-out alarm signal when any fault condition occurs except the fault condition where the number of faults occurring in the fault detection circuits in different directions is equal to 2.

3. The nuclear power steam turbine first-out alarm judgment device according to claim 1, characterized in that: The voting mechanism settings of the first selection module and the second selection module are the same.

4. The nuclear power steam turbine first-out alarm judgment device according to claim 1, characterized in that: The forward direction fault detection circuit is a high-high signal fault detection circuit, and the reverse direction fault detection circuit is a low-low signal fault detection circuit; or, the forward direction fault detection circuit is a low-low signal fault detection circuit, and the reverse direction fault detection circuit is a high-high signal fault detection circuit.

5. The nuclear power steam turbine first-out alarm judgment device according to claim 1, characterized in that: The fault types detected by the fault detection circuit include at least pressure faults and temperature faults of the nuclear power steam turbine.

6. The nuclear power steam turbine first-out alarm judgment device according to claim 5, characterized in that: Each fault detection circuit in the redundant setting detects the same fault type at the same time.

7. A method for determining the first alarm of a nuclear power steam turbine, characterized in that: The method is applicable to a first-out alarm judgment device for a nuclear power steam turbine, which comprises: at least three redundant fault detection circuits, a first selection module, a second selection module, an AND gate, a first OR gate, and a second OR gate; wherein each of the fault detection circuits is connected to the nuclear power steam turbine; each of the fault detection circuits comprises a forward direction fault detection circuit and a reverse direction fault detection circuit; and the forward direction fault detection circuit and the reverse direction fault detection circuit of the same fault detection circuit will not fail at the same time; wherein each of the forward direction fault detection circuits is connected to the input end of the first selection module and the input end of the first OR gate; each of the reverse direction fault detection circuits is connected to the input end of the second selection module and the input end of the second OR gate; the output end of the first OR gate and the output end of the second OR gate are both connected to the input end of the AND gate; the voting mechanism setting of the first selection module and the second selection module comprises one of three-out-of-two and four-out-of-two; The method comprises: When faults occur in the fault detection circuits in different directions, and only one of the forward direction fault detection circuits fails and only one of the reverse direction fault detection circuits fails, a first alarm signal is issued.

8. The nuclear power steam turbine first alarm judgment method according to claim 7, characterized in that: The nuclear power steam turbine first-out alarm judgment device further includes: a first NOT gate and a second NOT gate; wherein the first NOT gate input end is connected to the output end of the first selection module, and the first NOT gate output end is connected to the AND gate input end; the second NOT gate input end is connected to the output end of the second selection module, and the second NOT gate output end is connected to the AND gate input end; The method further comprises: When any fault condition occurs except the fault condition where the number of fault detection circuits in different directions that are faulty is equal to 2, a first-out alarm signal is issued.

Images