CN111816505B - Control circuit of quick-closing electromagnetic valve of nuclear power plant and main steam system - Google Patents

Abstract

The invention belongs to the technical field of nuclear power station main steam systems, and provides a nuclear power plant quick-closing solenoid valve control circuit and a main steam system, wherein the nuclear power plant quick-closing solenoid valve control circuit comprises a first solenoid valve control circuit and a second solenoid valve control circuit which are designed in a redundant manner, the first solenoid valve control circuit comprises a first relay, a second relay, a third relay, a first self-holding loop, a second self-holding loop and a first quick-closing relay circuit, wherein the first relay and the second relay are changed into normally-open contacts which are connected in series to control the third relay, namely a conduction relay, the normally-open contacts of the third relay sent to the self-holding loop are changed into normally-closed contacts, so that the same logic function as the original design is realized, the third relay is changed into a normally-demagnetized state from normally-excited state during power operation, the excitation of an A-column quick-closing solenoid valve caused by single fault of the third relay can be effectively avoided, and further, the fault of closing the main steam isolation valve occurs, and the driving reliability of the main steam isolation valve is improved.

Description

Nuclear power plant quick-close solenoid valve control circuit and main steam system

technical field

The invention belongs to the technical field of main steam systems of nuclear power plants, and in particular relates to a control circuit of a quick-closing electromagnetic valve of a nuclear power plant and a main steam system.

Background technique

At present, the main steam system (VVP) isolation valve VVP001/002/003VV undertakes an important safety function. When the reactor protection system (RPR) sends a steam isolation signal, it must be quickly closed within 5s. Its control equipment mainly includes: relay circuit, solenoid valve, wrong oil valve, remote control operation switch and valve position switch, etc. It is divided into two columns to realize four operating modes: fast closing, slow closing, partial closing and valve opening.

VVP001/002/003VV valve control adopts two columns of redundant logic, and a dual-channel circuit (CH1/CH2) is specially set for the valve opening signal self-holding circuit. The overall reliability of the logic channel is high, which can basically avoid the failure of relay or relay during the power operation of the unit. A single fault in the line causes the valve to close unexpectedly. The fast-closing solenoid valve control relay circuit is the core of the main steam isolation valve control circuit, and its reliability determines the reliability of the main steam isolation valve control.

Among them, the valve closing signal outputs a level signal to the self-holding circuit through the relay, including two relays and a conduction relay at the back end of the emergency valve closing command and partial valve closing test signal. The normally closed contacts of the two relays that receive the signal pass through After being connected in parallel, it is connected to the coil of the conduction relay at the back end, the normally open contact of the conduction relay is connected to the self-holding circuit, and the third relay is in the normal excitation state, so that the self-holding circuit is in the excitation state, so as to ensure the fast closing of the back-end connection. The solenoid valve is in the state of demagnetization and stop working. However, when the conduction relay itself or the two relays at the front end work abnormally, the self-holding circuit resets and is in a demagnetization state, which causes the quick-closing solenoid valve connected at the back end to work, and finally Causes the main steam isolation valve to close.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a control circuit of a quick-closing solenoid valve in a nuclear power plant, which aims to solve the problem of low reliability of the traditional solenoid valve control circuit.

A first aspect of the embodiments of the present invention provides a control circuit for a quick-close solenoid valve in a nuclear power plant, including a first solenoid valve control circuit and a second solenoid valve control circuit;

The first solenoid valve control circuit includes a first relay, a second relay, a third relay, a first self-holding circuit, a second self-holding circuit and a first quick-closing relay circuit;

The first normally open contact of the first relay and the first normally open contact of the second relay are connected in series with the coil of the third relay, and the first normally closed node of the third relay is connected to the coil of the third relay. The signal input end of the first self-holding circuit is connected, the second normally closed contact of the third relay is connected with the signal input end of the second self-holding circuit, and the signal output end of the first self-holding circuit is connected and the signal output end of the second self-holding loop are respectively connected with the signal input end of the first fast-closing relay circuit;

The second solenoid valve control circuit is used to control the action of the quick-closing solenoid valve of the column B, and the quick-closing solenoid valve of the column A and the quick-closing solenoid valve of the column B indirectly and redundantly control the action of the main steam isolation valve;

The first relay is used to receive the emergency valve closing command of column A;

The second relay is used to receive the partial valve closing test signal of column A;

The first self-holding circuit and the second self-holding circuit are used to switch from the excitation state to the de-excitation state when the third relay is in the excitation state, and respectively output the solenoid valve closing signal to the first fast relay. Close the relay circuit;

The first quick-closing relay circuit is used to control the excitation of the quick-closing solenoid valve of column A when receiving the closing signal of the solenoid valve, so as to close the main steam isolation valve.

In one embodiment, the first solenoid valve control circuit further includes a fourth relay, and the coil AND operation of the fourth relay receives the B column emergency valve closing command and the B column partial valve closing test of the second solenoid valve control circuit signal, the first normally closed node of the fourth relay is connected to the signal input terminal of the first self-holding circuit, and the second normally closed contact of the fourth relay is connected to the signal input of the second self-holding circuit The signal output terminal of the first self-holding circuit and the signal output terminal of the second self-holding circuit are respectively connected to the signal input terminal of the first fast-closing relay circuit;

The first self-maintaining loop and the second self-maintaining loop are used to switch from the excitation state to the de-excitation state when the fourth relay is in the excitation state, and output a solenoid valve closing signal to the first fast close relay circuit;

The first quick-closing relay circuit is used to control the excitation of the quick-closing solenoid valve of column A when receiving the closing signal of the solenoid valve, so as to close the main steam isolation valve.

In one embodiment, the first self-holding loop includes a first AND gate and a fifth relay in a normally-excited state, the second self-holding loop includes a second AND gate and a sixth relay in a normally-excited state, The first quick-closing relay circuit includes a first delay relay and a first OR gate;

The input end of the first AND gate is connected to the third relay, the fourth relay and receives the full-close control signal and the slow-close control signal, and the output end of the first AND gate is connected to the coil of the fifth relay connect;

The input end of the second AND gate is connected to the third relay, the fourth relay and receives the full-close control signal and the slow-close control signal, and the output end of the second AND gate is connected to the coil of the sixth relay connect;

The normally closed contact of the fifth relay and the normally closed contact of the sixth relay are connected in series with the coil of the first delay relay, and the normally open contact of the first delay relay is connected to the coil of the first delay relay. The signal input end of the first OR gate is connected, and the signal output end of the first OR gate is connected with the coil of the column A quick-closing solenoid valve.

In one embodiment, the first solenoid valve control circuit further includes a second time delay relay, the coil of the second time delay relay is connected to the full-off control signal, and the first time delay relay of the second time delay relay is connected to the fully-closed control signal. The normally closed contact is connected to the signal input end of the first AND gate, and the second normally closed contact of the second delay relay is connected to the signal input end of the second AND gate.

In one embodiment, the second solenoid valve control circuit includes a seventh relay, an eighth relay, a third self-holding loop, a fourth self-holding loop, and a second fast-closing relay circuit;

The normally closed contact of the seventh relay and the normally closed contact of the eighth relay are connected in series with the coil of the fourth relay, and the normally open contact of the seventh relay is also connected to the eighth relay. The coil is connected with the partial valve closing test signal OR operation of the B column, the normally open contact of the eighth relay is connected with the signal input end of the second fast-closing relay circuit, and the third self-holding circuit is The signal input terminal is connected with the signal output terminal of the first self-holding loop, the signal input terminal of the fourth self-holding loop is connected with the signal output terminal of the second self-holding loop, and the signal output terminal of the third self-holding loop is connected. The signal output end and the signal output end of the fourth self-holding loop are also respectively connected with the signal input end of the second quick-closing relay circuit;

The seventh relay is used to receive the emergency valve closing command of column B;

The eighth relay is used to receive the partial valve closing test signal of column B;

The third self-holding loop is used to switch from the excitation state to the loss-of-excitation state when the first self-holding loop loses the excitation state, and outputs a solenoid valve closing signal to the second fast-closing relay circuit;

the fourth self-holding loop is used to switch from the excitation state to the loss-of-excitation state when the second self-holding loop loses the excitation state, and outputs a solenoid valve closing signal to the second fast-closing relay circuit;

The second quick-closing relay circuit is used to control the excitation of the quick-closing solenoid valve of column B when receiving the closing signal of the solenoid valve, so as to close the main steam isolation valve.

In one embodiment, the third self-holding circuit includes a ninth relay in a normally-excited state, the fourth self-holding circuit includes a tenth relay in a normally-excited state, and the second fast-closing relay circuit includes a Three delay relays and a second OR gate;

The normally closed contact of the ninth relay and the normally closed contact of the tenth relay are connected in series with the coil of the third delay relay, and the normally open contact of the third delay relay is connected to the coil of the third delay relay. The signal input end of the second OR gate is connected, and the signal output end of the second OR gate is connected with the coil of the A-row quick-closing solenoid valve.

In one embodiment, the second normally open contact of the first relay is connected to the coil of the second relay, and the level signal input by the normally open contact of the first relay is related to the column A part. The valve test signal or operation is input to the coil of the second relay, the second normally open contact of the second relay is connected to the signal input end of the first quick-closing relay circuit, and the second normally open contact of the second relay is connected to the signal input end of the first quick-closing relay circuit. Two normally open contacts are connected to the input end of the first OR gate.

In one embodiment, the normally open contact of the seventh relay is connected to the coil of the eighth relay, and the level signal input by the normally open contact of the seventh relay is connected to the partial valve closing test in column B The signal is input to the coil of the eighth relay after OR operation, and the normally open contact of the eighth relay is also connected to the input end of the second OR gate.

In one embodiment, the first solenoid valve control circuit further includes an eleventh relay, a coil of the eleventh relay inputs the slow closing control signal, and a first normally closed contact of the eleventh relay It is connected with the signal input end of the first AND gate, and the second normally closed contact of the eleventh relay is connected with the signal input end of the second AND gate.

A second aspect of the embodiments of the present invention provides a main steam system, including a high-pressure nitrogen tank, a column A hydraulic system, a column B hydraulic system, a fuel tank, a gas supply system, and the control circuit for the quick-closing solenoid valve of the nuclear power plant as described above , the hydraulic system of column A and the hydraulic system of column B are redundantly arranged on the pipeline between the high-pressure nitrogen tank and the oil tank, and the gas supply system is used to pass the liquid in the oil tank through The gas is pumped into the pipeline, and the control circuit of the quick-closing solenoid valve of the nuclear power plant is electrically connected to the quick-closing solenoid valves in the hydraulic system of the column A and the hydraulic system of the column B, respectively.

In the present invention, a control circuit of a quick-closing solenoid valve of a nuclear power plant is composed of a first solenoid valve control circuit and a second solenoid valve control circuit, and the two solenoid valves respectively control the actions of the redundantly designed first and second quick-closing solenoid valves. , the first solenoid valve control circuit includes a first relay, a second relay, a third relay, a first self-holding circuit, a second self-holding circuit and a first quick-closing relay circuit, wherein the first relay and the second relay are changed to The normally open contact is connected in series to control the third relay, that is, the conduction relay. The normally open contact sent by the third relay to the self-holding circuit is changed to a normally closed contact to achieve the same logic function as the original design. Changing from constant excitation to constant demagnetization can effectively avoid the excitation of the quick-closing solenoid valve of column A caused by a single fault of the third relay, which in turn causes the failure of the main steam isolation valve to close, and improves the driving reliability of the main steam isolation valve.

Description of drawings

1 is a schematic structural diagram of a main steam system provided by an embodiment of the present invention;

2 is a schematic structural diagram of a conventional first solenoid valve control circuit;

3 is a schematic structural diagram of a conventional second solenoid valve control circuit;

4 is a schematic structural diagram of a first solenoid valve control circuit according to an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a second solenoid valve control circuit according to an embodiment of the present invention.

Detailed ways

In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention.

In addition, the terms "first" and "second" are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature defined as "first" or "second" may expressly or implicitly include one or more of that feature. In the description of the present invention, "plurality" means two or more, unless otherwise expressly and specifically defined.

A first aspect of the embodiments of the present invention provides a control circuit for a quick-closing solenoid valve of a nuclear power plant, which is suitable for a main steam system.

As shown in Figure 1, the main steam system includes a high-pressure nitrogen tank, a column A hydraulic system, a column B hydraulic system, an oil tank, a gas supply system and the control circuit of the quick-closing solenoid valve of the nuclear power plant as above, the A column hydraulic system and the B column The hydraulic system is redundantly arranged on the pipeline between the high-pressure nitrogen tank and the fuel tank. The gas supply system is used to pump the liquid in the fuel tank into the pipeline through the gas. The high-pressure nitrogen tank is switched on and off through the main steam isolation valve MSIV. SM3, SM5 and SM7 are respectively the fully open limit switch, fully closed limit switch and partially closed limit switch of the main steam isolation valve MSIV. 251EL is the switch solenoid valve in the hydraulic system of column A, and 271EL is the hydraulic system of column B. 251DR is the quick-closing and wrong oil valve in the hydraulic system of column A, 271DR is the quick-closing and wrong oil valve in the hydraulic system of column B, 261EL is the test solenoid valve in the hydraulic system of column A, VVP281EL is the test solenoid valve in the hydraulic system of row B, VVP261DR is the fault oil valve in the hydraulic system of row A, VVP281DR is the test valve of the fault oil valve, each solenoid valve, fault oil valve and the main steam isolation valve The working status of MSIV is shown in Table 1.

Table 1

As shown in Figure 1, the VVP001 valve control adopts the redundant logic of columns A and B, and sets a dual-channel circuit (CH1/CH2) for the self-holding circuit of the valve opening signal. The overall reliability of the logic channel is high, which can basically avoid the operation period of the unit power. Unexpected closing of the valve due to a single fault in a relay or line. The quick-closing solenoid valve control circuit is the core of the main steam isolation valve MSIV control circuit, and its reliability determines the reliability of the main steam isolation valve MSIV control, as shown in Figure 2 and Figure 3, Figure 2 and Figure 3 are A, Logic control circuit diagram of column B quick-closing solenoid valve 271EL.

According to the circuit analysis, the first relay J1 and the second relay J2 receive the emergency valve closing command of column A and the partial valve closing test signal of column A, and are respectively connected to the coil of the third relay J3 at the rear through the normally closed contact after being connected in parallel. , the normally open contact of the third relay J3 is connected to the first self-holding circuit and the second self-holding circuit 20, and the third relay J3 is in a normal excitation state, so that the self-holding circuit is in an excitation state, thereby ensuring the fast connection of the rear end The closing solenoid valve is in the demagnetization stop working state, but when the third relay J3 itself or the two relays at the front end work abnormally, the first self-holding circuit and the second self-holding circuit 20 are reset and are in a demagnetization state, resulting in The quick-closing solenoid valve connected at the rear end is energized, which eventually causes the main steam isolation valve MSIV to close.

Therefore, in order to solve this problem, the present invention proposes a control circuit for a quick-closing solenoid valve of a nuclear power plant. The control circuit for a quick-closing solenoid valve of a nuclear power plant includes a first solenoid valve control circuit and a second solenoid valve control circuit. The first solenoid valve controls The circuit and the second solenoid valve control circuit are respectively used to control the actions of the quick-closing solenoid valve 251EL of column A and the quick-closing solenoid valve 271EL of column B, wherein the first solenoid valve control circuit includes a first relay J1, a second relay J2, a third Relay J3 , the first self-holding circuit 10 , the second self-holding circuit 20 and the first quick-closing relay circuit 30 .

As shown in FIG. 4 , the first normally open contact of the first relay J1 and the first normally open contact of the second relay J2 in the first solenoid valve control circuit are connected in series with the coil of the third relay J3, and the first normally open contact of the second relay J2 is connected in series. The first normally closed node of the three relays J3 is connected to the signal input terminal of the first self-holding circuit 10, the second normally closed contact of the third relay J3 is connected to the signal input terminal of the second self-holding circuit 20, and the first self-holding circuit 20 The signal output end of the loop 10 and the signal output end of the second self-holding loop 20 are respectively connected with the signal input end of the first quick-closing relay circuit 30;

The second solenoid valve control circuit is used to control the action of the quick-closing solenoid valve 271EL of the column B, and the quick-closing solenoid valve 251EL of the column A and the quick-closing solenoid valve 271EL of the column B indirectly and redundantly control the action of the main steam isolation valve MSIV;

The first relay J1 is used to receive the emergency valve closing command of column A;

The second relay J2 is used to receive the partial valve closing test signal of column A;

The first self-holding circuit 10 and the second self-holding circuit 20 are used to switch from the excitation state to the de-excitation state when the third relay J3 is in the excitation state, and respectively output the solenoid valve closing signal to the first fast-closing relay circuit 30;

The first quick-close relay circuit 30 is used to control the excitation of the quick-close solenoid valve 251EL of column A when receiving the solenoid valve closing signal, so as to close the main steam isolation valve MSIV.

In this embodiment, the first relay J1 and the second relay J2 are changed to normally open contacts connected in series to control the third relay J3 to realize AND operation control, and the normally open contact sent by the third relay J3 to the self-holding circuit is changed to a normally open contact Close the contact to realize the same logic function as the original design. The third relay J3 changes from the normally excited state to the normally demagnetized state during the power operation, and the third relay J3 switches from the normally demagnetized state to the abnormal action of the normally excited state. Compared with the original probability of abnormal action of switching from the normally excited state to the normally demagnetized state, the probability is greatly reduced. At the same time, the normally closed contacts of the original first relay J1 and the second relay J2 are connected in parallel with the coil of the third relay J3, The OR operation is realized. When one of them fails, the third relay J3 will behave abnormally, causing the excitation of the quick-closing solenoid valve 251EL of column A, and finally causing the main steam isolation valve MSIV to close abnormally. In the improved scheme, the first relay J1 and the second relay J2 are connected in series with the coil of the third relay J3 through the normally open contact to realize the AND operation. If and only when the first relay J1 and the second relay J2 fail at the same time, the third relay J3 will have an abnormal movement Therefore, the probability of failure of the improved third relay J3 is reduced, thereby improving the driving reliability of the column A quick-closing solenoid valve 251EL and the main steam isolation valve MSIV.

The first self-holding circuit 10 and the second self-holding circuit 20 are used to hold and output the input valve opening signal and valve closing signal, so as to ensure that the quick-closing solenoid valve at the rear end is in a normally de-excited state or a normally-excited state, and its internal relay keeps Normally excited state.

The first fast-closing relay circuit 30 includes a delay relay J16, an abnormal fast-closing relay J18, a slow-closing relay J17, and a corresponding OR gate J20 structure, and the OR gate J20 is electrically connected to the column A fast-closing solenoid valve 251EL, and is received Control the excitation of the quick-closing solenoid valve 251EL of column A when the command of protection quick-closing, test slow-closing, manual quick-closing command or abnormal quick-closing command, so as to control the quick-closing wrong oil valve of column A hydraulic system to open the pressure relief, and finally control the main steam Isolation valve MSIV closed valve.

In the present invention, a control circuit of a quick-closing solenoid valve of a nuclear power plant is composed of a first solenoid valve control circuit and a second solenoid valve control circuit, and the two solenoid valves respectively control the actions of the redundantly designed first and second quick-closing solenoid valves. , the first solenoid valve control circuit includes a first relay J1, a second relay J2, a third relay J3, a first self-holding circuit 10, a second self-holding circuit 20 and a first fast-closing relay circuit 30, wherein the first relay J1 and the second relay J2 are changed to normally open contacts connected in series to control the third relay J3, which is a conduction relay, and the normally open contact sent to the self-holding circuit by the third relay J3 is changed to a normally closed contact to achieve the same as the original design. Logic function, the third relay J3 changes from constant excitation to constant demagnetization during power operation, which can effectively avoid the failure of the single fault of the third relay J3 to cause the excitation of the quick-closing solenoid valve 251EL of column A, which in turn causes the main steam isolation valve MSIV to close. occurred, improving the driving reliability of the main steam isolation valve MSIV.

It can be understood that the two columns of hydraulic systems and the corresponding solenoid valve control circuit are redundantly designed, and the signals between them interact. When a valve closing or valve opening command occurs in one of the columns, the two are synchronized through signal transmission, such as As shown in Figure 2 and Figure 3, when the seventh relay J22 and the seventh relay J23 of the second solenoid valve control circuit receive the emergency valve closing command of column B and the partial closing test signal of column B, the two relays will also feedback The valve command is sent to the fourth relay J4 of the first solenoid valve control circuit, wherein the seventh relay J22 and the seventh relay J23 are connected to the fourth relay J4 by means of parallel OR operation through normally closed contacts, which are the same as the third relay J3. In principle, there is also a risk that a single fault will cause the column A quick-closing solenoid valve 251EL and the main steam isolation valve MSIV to close abnormally. Therefore, based on the same solution, as shown in Figure 4, the first solenoid valve control circuit also includes a fourth relay. J4, the coil and operation of the fourth relay J4 receives the emergency valve closing command of column B and the partial valve closing test signal of column B of the second solenoid valve control circuit, the first normally closed node of the fourth relay J4 and the first self-holding circuit 10 The signal input terminal of the fourth relay J4 is connected to the signal input terminal of the second self-holding circuit 20, the signal output terminal of the first self-holding circuit 10 and the signal output terminal of the second self-holding circuit 20. The terminals are respectively connected with the signal input terminals of the first quick-closing relay circuit 30;

The first self-holding circuit 10 and the second self-holding circuit 20 are used to switch from the excitation state to the de-excitation state when the fourth relay J4 is in the excitation state, and output the solenoid valve closing signal to the first quick-closing relay circuit 30;

The first quick-closing relay circuit 30 is used to control the excitation of the quick-closing solenoid valve 251EL of column A when receiving the solenoid valve closing signal, so as to close the main steam isolation valve MSIV.

In this embodiment, the fourth relay J4 changes from the normally excited state to the normally demagnetized state during the power operation, and the probability of the abnormal action of the fourth relay J4 switching from the normally demagnetized state to the normally excited state is compared with the original one from the normally excited state The probability of abnormal action of state switching in the normal loss-of-magnetization state is greatly reduced. At the same time, the normally closed contacts of the original seventh relay J22 and the seventh relay J23 are connected in parallel with the coil of the fourth relay J4 to achieve OR operation. When one of them appears In the event of a fault, the fourth relay J4 will act abnormally, causing the excitation of the quick-closing solenoid valve 251EL of column A, and finally causing the main steam isolation valve MSIV to close abnormally. The open contact is connected in series with the coil of the fourth relay J4 to realize the AND operation. If and only when the seventh relay J22 and the seventh relay J23 fail at the same time, the fourth relay J4 will have an abnormal movement. Therefore, the improved fourth relay J4 The probability of failure of relay J4 is reduced, thereby improving the driving reliability of the quick-closing solenoid valve 251EL of column A and the main steam isolation valve MSIV.

As shown in Figure 2, the fifth relay J10 is one of the relays in the first self-holding circuit 10. Through further analysis, it is found that the fifth relay J10 has an abnormal coil or its normally closed contact of the first delay relay is abnormal. , will cause the excitation of the first delay relay, and trigger the excitation of the quick-closing solenoid valve 251EL of column A after a delay of the first preset time, resulting in the rapid closing of the main steam isolation valve MSIV. In order to solve this problem, in one embodiment, the first A self-holding circuit 10 includes a first AND gate J7 and a fifth relay J10 in a normally excited state, the second self-holding circuit 20 includes a second AND gate J12 and a sixth relay J14 in a normally excited state, and a first fast-closing relay The circuit 30 includes a first delay relay J16 and a first OR gate J20;

The input end of the first AND gate J7 is connected to the third relay J3, the fourth relay J4 and receives the full closing control signal and the slow closing control signal, and the output end of the first AND gate J7 is connected to the coil of the fifth relay J10;

The input end of the second AND gate J12 is connected to the third relay J3, the fourth relay J4 and receives the full-close control signal and the slow-close control signal, and the output end of the second AND gate J12 is connected to the coil of the sixth relay J14;

The normally closed contact of the fifth relay J10 and the normally closed contact of the sixth relay J14 are connected in series with the coil of the first delay relay J16, and the normally open contact of the first delay relay J16 is connected to the first OR gate J20 The signal input end of the first OR gate J20 is connected to the coil of the column A quick-closing solenoid valve 251EL.

In the present embodiment, the sixth relay J14 in the first self-holding loop 10 is connected in series with the fifth relay J10, so that the first delay relay J16 is controlled after the AND operation, and the fifth relay J10 can be effectively avoided. A single fault causes the first delay relay J16 to act.

As shown in Figure 1 and Figure 2, in the original circuit, SM5 is the valve closing limit switch of VVP001VV, and the self-holding circuit is opened through a conventional relay reset. During power operation, the relay is in a demagnetized state, such as SM5 mistakenly triggers the valve to close Signal (such as accidental touch by a person), the second delay relay J6 will be excited, reset the first self-holding circuit 10 and the second self-holding circuit 20, causing the excitation of the quick-closing solenoid valve 251EL of column A, and finally causing the main steam isolation valve MSIV to close , therefore, in order to solve this problem, in one embodiment, the first solenoid valve control circuit further includes a second delay relay J6, the coil of the second delay relay is connected to the fully-off control signal, and the second delay relay J6 A normally closed contact is connected to the signal input terminal of the first AND gate J7, and the second normally closed contact of the second delay relay is connected to the signal input terminal of the second AND gate J12.

In this embodiment, by setting the conventional relay as a delay relay, and the delay time is set to more than 5 seconds, when the full-close control signal is received for 5 seconds or more, the delay relay triggers the action, and resets the self-holding circuit, otherwise it will not act, thus avoiding the problem of closing the main steam isolation valve MSIV due to accidental touch by personnel.

As shown in FIG. 5 , in one embodiment, the second solenoid valve control circuit includes a seventh relay J22 , a seventh relay J23 , a third self-holding circuit 40 , a fourth self-holding circuit 50 and a second quick-closing relay circuit 60 ;

The normally closed contact of the seventh relay J22 and the normally closed contact of the seventh relay J23 are connected in series with the coil of the fourth relay J4, and the normally open contact of the seventh relay J22 is also connected to the coil of the seventh relay J23 and is connected to the coil of the fourth relay J4. Part of the valve closing test signal OR operation in column B, the normally open contact of the seventh relay J23 is connected to the signal input terminal of the second quick-closing relay circuit 60, and the signal input terminal of the third self-holding circuit 40 is connected to the first self-holding circuit 10. The signal output terminal of the fourth self-holding loop 50 is connected to the signal output terminal of the second self-holding loop 20, the signal output terminal of the third self-holding loop 40 is connected to the signal output terminal of the fourth self-holding loop 50 are also respectively connected with the signal input ends of the second quick-closing relay circuit 60;

The seventh relay J22 is used to receive the emergency valve closing command of column B;

The seventh relay J23 is used to receive the partial valve closing test signal of column B;

The third self-holding loop 40 is used for switching from the excitation state to the de-excitation state when the first self-holding loop 10 is in the de-excitation state, and outputs the solenoid valve closing signal to the second quick-closing relay circuit 60;

the fourth self-holding loop 50 is used for switching from the excitation state to the de-excitation state when the second self-holding loop 20 is in the de-excitation state, and outputs a solenoid valve closing signal to the second quick-closing relay circuit 60;

The second quick-close relay circuit 60 is used to control the excitation of the quick-close solenoid valve 271EL of column B when receiving the solenoid valve closing signal, so as to close the main steam isolation valve MSIV.

In this embodiment, based on the problem that the main steam isolation valve MSIV is closed due to a single abnormality of the fourth relay J4, the first solenoid valve control circuit is improved accordingly. At the same time, the seventh relay J22 and the seventh The normally closed contact of the relay J23 is improved to a normally open contact to connect the fourth relay J4, the fourth relay J4 is changed from the normally excited state to the normally demagnetized state during the power operation, and the fourth relay J4 is switched from the normally demagnetized state to the normal state. The probability of abnormal action in the excitation state is greatly reduced compared to the original probability of abnormal action in which the normal excitation state is switched to the normal demagnetization state. At the same time, the normally closed contacts of the original seventh relay J22 and the seventh relay J23 are connected in parallel. The coil of the four relays J4 realizes OR operation. When one of the relays fails, the fourth relay J4 will behave abnormally, causing the excitation of the quick-closing solenoid valve 251EL of column A, and finally causing the main steam isolation valve MSIV to close abnormally. In the scheme, the seventh relay J22 and the seventh relay J23 are connected in series with the coil of the fourth relay J4 through the normally open contact to realize the AND operation. If and only when the seventh relay J22 and the seventh relay J23 fail at the same time, the fourth relay The relay J4 will have abnormal movement. Therefore, the probability of failure of the improved fourth relay J4 is reduced, thereby improving the driving reliability of the column A quick-closing solenoid valve 251EL and the main steam isolation valve MSIV.

The second fast-closing relay circuit 60 includes a delay relay J28, an abnormal fast-closing relay J31, a slow-closing relay J30, and a corresponding OR gate J32 structure, and the OR gate J32 is electrically connected to the fast-closing solenoid valve 271EL of column B, and is Control the excitation of the quick-close solenoid valve 271EL of column B when the protection quick-close, test slow-close, manual quick-close command or abnormal quick-close command, so as to control the quick-close wrong oil valve of the hydraulic system of column B to open the pressure relief, and finally control the main steam Isolation valve MSIV closed valve.

As shown in Figure 3, the ninth relay J25 is one of the relays in the second self-holding circuit 20. Through further analysis, it is found that the ninth relay J25 has an abnormal coil or the normally closed contact of the third delay relay J28 is abnormal. , it will cause the excitation of the third delay relay J28, and trigger the excitation of the quick-closing solenoid valve 271EL of column B after the first preset time delay, resulting in the rapid closing of the main steam isolation valve MSIV. In order to solve this problem, as shown in Figure 5 In one embodiment, the third self-holding circuit 40 includes a ninth relay J25 in a normally excited state, the fourth self-holding circuit 50 includes a ninth relay J27 in a normally excited state, and the second fast-closing relay circuit 60 includes a Three delay relay J28 and second OR gate J32;

The normally closed contact of the ninth relay J25 and the normally closed contact of the ninth relay J27 are connected in series with the coil of the third delay relay J28, and the normally open contact of the third delay relay J28 is connected to the second OR gate J32 The signal input end of the second OR gate J32 is connected to the coil of the column A quick-closing solenoid valve 251EL.

In this embodiment, based on the same solution as the fifth relay J10, the ninth relay J27 in the third self-holding loop 40 leads a contact to be connected in series with the ninth relay J25, so as to realize the control of the third delay relay after the AND operation. J28, it can effectively avoid the action of the third delay relay J28 caused by the single fault of the ninth relay J25.

As shown in FIG. 4, in one embodiment, the second normally open contact of the first relay J1 is connected to the coil of the second relay J2, and the level signal input by the normally open contact of the first relay J1 is connected to the part of column A. The valve closing test signal or operation is input to the coil of the second relay J2, the second normally open contact of the second relay J2 is connected to the signal input end of the first quick-closing relay circuit 30, and the second normally open contact of the second relay J2 The contact is connected to the input terminal of the first OR gate J20.

In this embodiment, the second relay J2 is used to receive the partial closing test signal of column A and transmit the emergency valve closing command of column A output by the first relay J1. At the same time, as shown in FIG. 5 , in one embodiment, the seventh The normally open contact of the relay J22 is connected to the coil of the seventh relay J23. The level signal input by the normally open contact of the seventh relay J22 and the valve closing test signal of column B are input to the coil of the seventh relay J23 after calculation. The normally open contact of the seventh relay J23 is also connected to the input end of the second OR gate J32. The seventh relay J23 is used to receive the partial closing test signal of column B and transmit the emergency valve closing command of column B output by the seventh relay J22.

In one embodiment, the first solenoid valve control circuit further includes an eleventh relay J5, the coil of the eleventh relay J5 inputs a slow closing control signal, the first normally closed contact of the eleventh relay J5 is connected to the first AND gate The signal input terminal of J7 is connected, and the second normally closed contact of the eleventh relay J5 is connected to the signal input terminal of the second AND gate J12. In this embodiment, the eleventh relay J5 is used to transmit a manual slow closing signal.

As shown in FIG. 1 , the present invention also proposes a main steam system, which includes a high-pressure nitrogen tank, a column A hydraulic system, a column B hydraulic system, an oil tank, a gas supply system and a nuclear power plant quick-close solenoid valve control The specific structure of the control circuit of the quick-closing solenoid valve of the nuclear power plant refers to the above-mentioned embodiments. Since the main steam system adopts all the technical solutions of the above-mentioned embodiments, it has at least all the benefits brought by the technical solutions of the above-mentioned embodiments. The effect will not be repeated here. Among them, the hydraulic system of column A and the hydraulic system of column B are redundantly arranged on the pipeline between the high-pressure nitrogen tank and the fuel tank, and the gas supply system is used to pump the liquid in the fuel tank into the pipeline through the gas. The valve control circuit is respectively electrically connected with the quick-closing solenoid valves in the hydraulic system of column A and the hydraulic system of column B.

The high-pressure nitrogen tank is controlled by the main steam isolation valve MSIV. SM3, SM5 and SM7 are respectively the fully open limit switch, fully closed limit switch and partially closed limit switch of the main steam isolation valve MSIV. 251EL is the hydraulic pressure of column A. The switch solenoid valve in the system, 271EL is the quick-close solenoid valve in the B-row hydraulic system, 251DR is the quick-close wrong oil valve in the A-row hydraulic system, and 271DR is the quick-close wrong oil valve in the B-row hydraulic system Valve, 261EL is the test solenoid valve in column A hydraulic system, VVP281EL is the test solenoid valve in column B hydraulic system, VVP261DR is the error checking oil valve in column A hydraulic system, VVP281DR is the test error checking oil valve oil valve.

As shown in Figure 1, the VVP001 valve control adopts the redundant logic of columns A and B, and sets a dual-channel circuit (CH1/CH2) for the self-holding circuit of the valve opening signal. The overall reliability of the logic channel is high, which can basically avoid the operation period of the unit power. Unexpected closing of the valve due to a single fault in a relay or line.

The above-mentioned embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it is still possible to implement the foregoing implementations. The technical solutions described in the examples are modified, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the within the protection scope of the present invention.

Claims (10)

1. A control circuit of a quick-closing electromagnetic valve of a nuclear power plant is characterized by comprising a first electromagnetic valve control circuit and a second electromagnetic valve control circuit;

the first electromagnetic valve control circuit comprises a first relay, a second relay, a third relay, a first self-holding loop, a second self-holding loop and a first quick-closing relay circuit;

the first normally open contact of the first relay and the first normally open contact of the second relay are connected in series and then connected with a coil of the third relay, the first normally closed node of the third relay is connected with the signal input end of the first self-holding loop, the second normally closed contact of the third relay is connected with the signal input end of the second self-holding loop, and the signal output end of the first self-holding loop and the signal output end of the second self-holding loop are respectively connected with the signal input end of the first quick-closing relay circuit;

the second electromagnetic valve control circuit is used for controlling the action of the B-column fast-closing electromagnetic valves, and the A-column fast-closing electromagnetic valves and the B-column fast-closing electromagnetic valves indirectly control the action of the main steam isolating valve in a redundant manner;

the first relay is used for receiving an emergency valve closing command of the A column;

the second relay is used for receiving a partial valve closing test signal of the column A;

the first self-holding loop and the second self-holding loop are used for switching from an excitation state to a de-excitation state when the third relay is in an excitation state, and respectively outputting electromagnetic valve closing signals to the first quick-closing relay circuit;

and the first quick-closing relay circuit is used for controlling the excitation of the A-column quick-closing solenoid valves when receiving the solenoid valve closing signal so as to close the main steam isolation valve.

2. The nuclear power plant quick-closing solenoid valve control circuit of claim 1, wherein the first solenoid valve control circuit further comprises a fourth relay, a coil of the fourth relay is connected with a signal input end of a first self-holding loop, a second normally-closed contact of the fourth relay is connected with a signal input end of a second self-holding loop, and a signal output end of the first self-holding loop and a signal output end of the second self-holding loop are respectively connected with the signal input end of the first quick-closing relay circuit;

the first self-holding loop and the second self-holding loop are used for switching from an excitation state to a de-excitation state when the fourth relay is in an excitation state and outputting an electromagnetic valve closing signal to the first quick-closing relay circuit;

and the first quick-closing relay circuit is used for controlling the excitation of the A-column quick-closing solenoid valve when receiving the closing signal of the solenoid valve so as to close the main steam isolation valve.

3. The nuclear power plant quick-closing solenoid valve control circuit of claim 2, wherein the first self-holding loop comprises a first and gate and a fifth relay in a normally excited state, the second self-holding loop comprises a second and gate and a sixth relay in a normally excited state, and the first quick-closing relay circuit comprises a first delay relay and a first or gate;

the input end of the first AND gate is connected with the third relay and the fourth relay and receives a full-off control signal and a slow-off control signal, and the output end of the first AND gate is connected with a coil of the fifth relay;

the input end of the second AND gate is connected with the third relay and the fourth relay and receives a full-off control signal and a slow-off control signal, and the output end of the second AND gate is connected with a coil of the sixth relay;

the normally closed contact of the fifth relay and the normally closed contact of the sixth relay are connected in series and then connected with the coil of the first time delay relay, the normally open contact of the first time delay relay is connected with the signal input end of the first OR gate, and the signal output end of the first OR gate is connected with the coil of the A-row quick-closing electromagnetic valve.

4. The nuclear power plant quick-closing solenoid valve control circuit of claim 3, wherein the first solenoid valve control circuit further comprises a second time delay relay, a coil of the second time delay relay is connected to the fully-closed control signal, a first normally-closed contact of the second time delay relay is connected to a signal input end of the first AND gate, and a second normally-closed contact of the second time delay relay is connected to a signal input end of the second AND gate.

5. The nuclear power plant fast-closing solenoid valve control circuit of claim 2, wherein the second solenoid valve control circuit comprises a seventh relay, an eighth relay, a third self-holding loop, a fourth self-holding loop, and a second fast-closing relay circuit;

the normally closed contact of the seventh relay and the normally closed contact of the eighth relay are connected in series and then connected with a coil of the fourth relay, the normally open contact of the seventh relay is further connected with the coil of the eighth relay and is used for performing valve closing test signals or calculation with the column B part, the normally open contact of the eighth relay is connected with the signal input end of the second quick-closing relay circuit, the signal input end of the third self-holding loop is connected with the signal output end of the first self-holding loop, the signal input end of the fourth self-holding loop is connected with the signal output end of the second self-holding loop, and the signal output end of the third self-holding loop and the signal output end of the fourth self-holding loop are further connected with the signal input end of the second quick-closing relay circuit respectively;

the seventh relay is used for receiving a B-column emergency valve closing command;

the eighth relay is used for receiving a partial valve closing test signal of the column B;

the third self-holding loop is used for switching from an excitation state to a demagnetization state when the first self-holding loop is in the demagnetization state, and outputting an electromagnetic valve closing signal to the second quick-closing relay circuit;

the fourth self-holding loop is used for switching from an excitation state to a demagnetization state when the second self-holding loop is in the demagnetization state and outputting an electromagnetic valve closing signal to the second quick-closing relay circuit;

and the second quick-closing relay circuit is used for controlling the B-column quick-closing electromagnetic valves to be excited when receiving the electromagnetic valve closing signal so as to close the main steam isolation valve.

6. The nuclear plant quick-closing solenoid valve control circuit of claim 5, wherein the third self-holding loop comprises a ninth relay in a normally energized state, the fourth self-holding loop comprises a tenth relay in a normally energized state, and the second quick-closing relay circuit comprises a third delay relay and a second OR gate;

the normally closed contact of ninth relay with the normally closed contact series connection back of tenth relay with third time delay relay's coil connection, third time delay relay's normally open contact with the signal input part of second OR gate is connected, the signal output part of second OR gate with the coil connection of A row fast closed solenoid valve.

7. The control circuit of the nuclear power plant quick-closing solenoid valve according to claim 3, wherein a second normally open contact of the first relay is connected with a coil of the second relay, a level signal input by the normally open contact of the first relay is input to the coil of the second relay after being subjected to the on-column partial valve closing test signal or operation, a second normally open contact of the second relay is connected with a signal input end of the first quick-closing relay circuit, and a second normally open contact of the second relay is connected with an input end of the first or gate.

8. The control circuit of the nuclear power plant quick-closing solenoid valve according to claim 6, wherein a normally open contact of the seventh relay is connected with a coil of the eighth relay, a level signal input by the normally open contact of the seventh relay is input to the coil of the eighth relay after being subjected to the or operation with the column B partial valve closing test signal, and the normally open contact of the eighth relay is further connected with an input end of the second or gate.

9. The nuclear power plant quick-closing solenoid valve control circuit of claim 3, wherein the first solenoid valve control circuit further comprises an eleventh relay, a coil of the eleventh relay inputs the slow-closing control signal, a first normally closed contact of the eleventh relay is connected with a signal input end of the first AND gate, and a second normally closed contact of the eleventh relay is connected with a signal input end of the second AND gate.

10. A main steam system, including high-pressure nitrogen gas jar, A row hydraulic system, B row hydraulic system, oil tank, gas supply system and according to any one of claims 1 ~ 9 the quick-closing solenoid valve control circuit of nuclear power plant, A row hydraulic system with B row hydraulic system redundancy sets up high-pressure nitrogen gas jar with on the pipeline between the oil tank, gas supply system is used for with liquid in the oil tank passes through high-pressure gas pump and goes into in the pipeline, nuclear power plant quick-closing solenoid valve control circuit respectively with A row hydraulic system with quick-closing solenoid valve electric connection in the B row hydraulic system.

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