CN219692402U - Valve proximity switch, sensing equipment and nuclear island start control system - Google Patents

Abstract

The utility model provides a valve proximity switch, sensing equipment and a nuclear island starting control system, and relates to the technical field of valve proximity switches. By using the valve proximity switch provided by the embodiment of the utility model in a nuclear power valve of a nuclear island system, the first switch unit is connected with the second switch unit, so that control information can be output when the on-off states of the two switch units are the same, an electrical control system connected with the nuclear power valve is prevented from receiving an incorrect valve position feedback signal, and the reliability of the valve proximity switch can be improved.

Description

Valve proximity switch, sensing equipment and nuclear island start control system

Technical Field

The utility model relates to the technical field of valve proximity switches, in particular to a valve proximity switch, sensing equipment and a nuclear island starting control system.

Background

The nuclear power valve is a key part for transporting fuel and energy during shutdown and refueling in a nuclear island system, and the running stability and reliability of the nuclear power valve are critical to the safety of a nuclear power plant. The valve proximity switch is used as a non-contact type induction limit switch, the switch contact is driven to act through the magnetic field force of the magnetic target to realize signal switching, and the switch is not directly and mechanically connected with a valve, so that the influence of high temperature and vibration is avoided, and the switch is widely applied to nuclear power equipment.

In the related art, the valve proximity switch only comprises a switch unit, when the installation environment of the valve proximity switch has high-frequency vibration or impact, the valve proximity switch may have false triggering or false detachment phenomenon of a switch contact, that is, the reliability of the valve proximity switch is lower, and an electrical control system connected with a nuclear power valve may receive an incorrect valve position feedback signal, which may pose a serious threat to the normal operation of a nuclear island.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, the present utility model provides a valve proximity switch, a sensing device and a nuclear island start control system, so as to solve the above-mentioned technical problems.

The utility model provides a valve proximity switch, comprising:

each switch unit at least comprises an input end and a first output end, and a normally open switch for inducing the action of a magnet is arranged between the input end and the first output end; the first output end of the first switch unit is connected with the input end of the second switch unit, the input end of the first switch unit is the input end of the valve proximity switch, and the first output end of the second switch unit is the first output end of the valve proximity switch.

In an embodiment of the utility model, the valve proximity switch further includes at least two connectors and at least one wire, the first output end of the first switch unit is connected to one end of the wire through one of the connectors, and the input end of the second switch unit is connected to the other end of the wire through the other connector.

In an embodiment of the utility model, the valve proximity switch further includes at least a third switch unit, each switch unit further includes a second output end, a normally closed switch for sensing the action of the magnet is disposed between the input end and the second output end, the second output end of the first switch unit is connected with the input end of the third switch unit, and the second output end of the third switch is the second output end of the valve proximity switch.

In an embodiment of the utility model, the valve proximity switch further includes at least four connectors and at least two wires, the first output end of the first switch unit is connected to one end of the first wire through the first connector, the input end of the second switch unit is connected to the other end of the first wire through the second connector, the second output end of the first switch unit is connected to one end of the second wire through the third connector, and the input end of the third switch unit is connected to the other end of the second wire through the fourth connector.

In an embodiment of the present utility model, the first output end and the second output end of the first switch unit, the input end and the second output end of the second switch unit, and the input end and the first output end of the third switch unit are set to be a first length, and the input end of the first switch unit, the first output end of the second switch unit, and the second output end of the third switch unit are set to be a second length, and the second length is greater than the first length.

To achieve the above and other related objects, the present utility model provides an induction apparatus comprising: the valve proximity switch according to any one of the foregoing embodiments, wherein the valve proximity switch is configured to sense a magnetic body, one of the valve proximity switches is a first sensing switch, the other valve proximity switch is a second sensing switch, a distance value between the first sensing switch and the magnetic body is a first distance value, a distance value between the second sensing switch and the magnetic body is a second distance value, a difference value between the first distance value and the second distance value is greater than a preset value, and both the first sensing switch and the second sensing switch are sensing switches;

when the first inductive switch senses the magnet, a normally open switch in the first inductive switch is closed; when the second inductive switch senses the magnet, a normally open switch in the second inductive switch is closed.

In an embodiment of the present utility model, each of the inductive switches includes at least two valve proximity switches, an input end of the valve proximity switch in each of the inductive switches is connected to an input end of the inductive device, a first output end of each of the valve proximity switches in the first inductive switch is connected to a first normally open output end of the inductive device, and a first output end of each of the valve proximity switches in the second inductive switch is connected to a second normally open output end of the inductive device.

In one embodiment of the present utility model, all of the valve proximity switches are parallel to each other.

In an embodiment of the utility model, the sensing device further includes a circuit board, the first sensing switch is disposed on one surface of the circuit board, and the second sensing switch is disposed on the other surface of the circuit board.

To achieve the above and other related objects, the present utility model provides a nuclear island start control system, comprising:

a magnet and an induction device according to any of the preceding embodiments, the magnet being arranged on one side of the output end of the induction device.

As described above, the valve proximity switch, the sensing device and the nuclear island start control system provided by the utility model have the following beneficial effects:

the utility model relates to a valve proximity switch, which at least comprises two switch units, namely a first switch unit and a second switch unit, wherein each switch unit at least comprises an input end and a first output end, a normally open switch for sensing the action of a magnet is arranged between the input end and the first output end, the first output end of the first switch unit is connected with the input end of the second switch unit, the input end of the first switch unit is the input end of the valve proximity switch, and the first output end of the second switch unit is the first output end of the valve proximity switch. By connecting the first switch unit with the second switch unit, control information can be output when the on-off states of the two switch units are the same, and the reliability of the valve proximity switch can be improved.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the utility model as claimed.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the utility model and together with the description, serve to explain the principles of the utility model. It is evident that the drawings in the following description are only some embodiments of the present utility model and that other drawings may be obtained from these drawings without inventive effort for a person of ordinary skill in the art. In the drawings:

FIG. 1 is a schematic circuit diagram of a valve proximity switch according to an exemplary embodiment of the present utility model;

FIG. 2 is a schematic circuit diagram of a valve proximity switch shown in another exemplary embodiment of the present utility model;

FIG. 3 is a schematic view of the mounting structure of the valve proximity switch of FIG. 2;

FIG. 4 is a schematic view of the mounting base of the valve proximity switch of FIG. 3;

FIG. 5 is a schematic circuit diagram of an inductive device shown in an exemplary embodiment of the utility model;

fig. 6 is a schematic structural view of an induction device according to another exemplary embodiment of the present utility model;

FIG. 7 is a schematic circuit diagram of the connection of a plurality of inductive switches in the inductive device of FIG. 6;

FIG. 8 is a schematic diagram of a circuit board of the induction device shown in FIG. 6;

FIG. 9 is a left side view of an inductive device shown in another exemplary embodiment of the utility model;

fig. 10 is an isometric view of the sensing device of fig. 9.

110-a first switching unit; 111-a first output of a first switching unit; 112-an input of a first switching unit; 113-a second output of the first switching unit; 120-a second switching unit; 121-a first output of a second switching unit; 130-a third switching unit; 132-an input of a third switching unit; 133-a second output of the third switch; 140-conducting wires; 150-mounting seats; 151-mounting holes; 152-wire vias; 510-a first inductive switch; 510 a-a valve proximity switch of the first inductive switch; 510 b-another valve proximity switch of the first inductive switch; 520-a second inductive switch; 520 a-a valve proximity switch of the second inductive switch; 520 b-another valve proximity switch of the second inductive switch; 530-a circuit board; an input of a COM-sensing device; NC 1-a first normally closed output end; NO 1-a first normally open output; NC 2-a second normally closed output end; NO 2-a second normally open output NO2; welding holes with m-phi 1.5 pins; n-phi 3 internal part fixing holes; p-phi 2 terminal hole; 10-magnet.

Detailed Description

Further advantages and effects of the present utility model will become readily apparent to those skilled in the art from the disclosure herein, by referring to the accompanying drawings and the preferred embodiments. The utility model may be practiced or carried out in other embodiments that depart from the specific details, and the details of the present description may be modified or varied from the spirit and scope of the present utility model. It should be understood that the preferred embodiments are presented by way of illustration only and not by way of limitation.

It should be noted that the illustrations provided in the following embodiments merely illustrate the basic concept of the present utility model by way of illustration, and only the components related to the present utility model are shown in the drawings and are not drawn according to the number, shape and size of the components in actual implementation, and the form, number and proportion of the components in actual implementation may be arbitrarily changed, and the layout of the components may be more complicated.

In the following description, numerous details are set forth in order to provide a more thorough explanation of embodiments of the present utility model, it will be apparent, however, to one skilled in the art that embodiments of the present utility model may be practiced without these specific details, in other embodiments, well-known structures and devices are shown in block diagram form, rather than in detail, in order to avoid obscuring the embodiments of the present utility model.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a valve proximity switch according to an exemplary embodiment of the present utility model. As can be seen with reference to fig. 1, the valve proximity switch 100 may include:

at least two switch units, namely a first switch unit 110 and a second switch unit 120, each switch unit at least comprises an input end and a first output end, and a normally open switch for sensing the action of the magnet is arranged between the input end and the first output end; the first output end 111 of the first switch unit 110 is connected to the input end 122 of the second switch unit 120, the input end 112 of the first switch unit 110 is an input end of a valve proximity switch, and the first output end 121 of the second switch unit 120 is a first output end of the valve proximity switch.

It should be noted that, in the process that the magnet approaches the valve proximity switch, only when both the first switch unit 110 and the second switch unit 120 are changed from normal open to normal closed, the input signal input through the input terminal of the first switch unit 110 may be output through the first output terminal of the second switch unit 120. That is, the output of the input signal needs to be achieved in the case that the on-off state of each switching unit is identical. By using the valve proximity switch provided by the embodiment of the utility model, the phenomenon of false triggering or false detachment of the contact caused by vibration and impact of the field working condition can be avoided, and the reliability of the valve proximity switch can be improved. The first output end 121 of the second switch unit 120 may be further connected to an input end of another switch unit, and the first output end of the other switch unit is used as a first output end of the valve proximity switch, that is, the valve proximity switch may include a series structure of a plurality of switch units, so as to output a control signal at the first output end when the actions of the plurality of switch units are consistent, otherwise, the first output end has no signal output, which may further improve the reliability of the valve proximity switch.

It should be noted that, the normally open switch of each switch unit can be located the sealed tube, and the input and the first output of each switch unit all stretch out the sealed tube, and the positional relationship of two at least switch units can stack from top to bottom, and the length of valve proximity switch can be reduced in so setting, is convenient for install the valve proximity switch. The positional relationship of at least two switch units may be a plane parallel, which is not limited in the embodiment of the present utility model.

When the valve proximity switch provided by the embodiment of the utility model is needed to be described, the valve proximity switch can be used for nuclear power valves of a nuclear island system. The nuclear power valve is used as a key component for transporting fuel and energy during shutdown and refueling of a nuclear island system, and the running stability and reliability of the nuclear power valve are critical to the safety of a nuclear power plant. The valve proximity switch is used as a core component of the nuclear power valve electrical control system, can be horizontally or vertically arranged on a valve limiting bracket, and monitors the key position state of the valve in real time in a mode of triggering the action of an internal element of the valve proximity switch by the action of an induction magnet (namely the induction magnetic field force), so that the action feedback of the valve and the accurate control of the valve position are completed, and the functions of interlocking control during normal operation of a nuclear island system, remote alarm indication under abnormal conditions of the system, automatic safety protection and the like are realized. The valve proximity switch is used as a non-contact type induction limit switch, the switch contact is driven to act through the magnetic field force of the magnetic target to realize signal switching, and the switch is not directly and mechanically connected with a valve, so that the influence of high temperature and vibration is avoided, and the switch is widely applied to nuclear power equipment.

The switching unit may be, for example, a SPST (single pole single throw) valve proximity switch. The SPST valve proximity switch can be packaged in a glass sealing tube, the inside of the glass sealing tube is in a vacuum state or filled with inert protective gas, the SPST valve proximity switch can sense the action of a magnet and is changed from a normally open state to a closed state or is restored from the closed state to the normally open state, and the structure can also be called as a reed switch structure.

In one embodiment of the present utility model, the valve proximity switch may further include at least two connectors and at least one wire, the first output terminal of the first switching unit is connected to one end of the wire through one connector, and the input terminal of the second switching unit is connected to the other end of the wire through the other connector. The connection between the first switch unit and the second switch unit is realized through the connecting piece and the lead, so that the second switch unit can be conveniently arranged at any relative position of the first switch unit, and the connection is realized. None of which are shown in fig. 1.

Referring to fig. 2, a schematic diagram of a valve proximity switch according to another exemplary embodiment of the present utility model is shown. As can be seen with reference to fig. 2, the valve proximity switch 200 may further include:

the third switch units 130 (not labeled in fig. 2), each of which further includes a second output end, a normally closed switch for sensing the action of the magnet is disposed between the input end and the second output end, the second output end 113 of the first switch unit 110 (not labeled in fig. 2) is connected to the input end 132 of the third switch unit 130, and the second output end 133 of the third switch 130 is a second output end of the valve proximity switch.

In one embodiment of the present utility model, the switching unit shown in fig. 1 or the switching unit shown in fig. 2 may be selected according to the number of control signals, which is not limited in the embodiment of the present utility model.

For example, in the valve proximity switch shown in fig. 2, the switching unit may be an SPDT (SinglePole DoubleThrow ) valve proximity switch, which may be formed of NC (Normal Close), NO (Normal open), COM (Common). The SPDT valve proximity switch can be packaged in a glass sealing tube and can sense the action of a magnet. The SPDT valve proximity switch can be composed of two magnetizable reeds (NO and COM) and a non-magnetic conductive reed (NC), wherein one magnetizable reed (COM) and the non-magnetic conductive reed (NO) can form a normally open switch, the two magnetizable reeds (COM and NC) can form a normally closed switch, when a magnetic field of the triggering device (namely a magnetic field determined by a magnet) approaches the SPDT valve proximity switch, a magnetic field line passes through the two magnetizable reeds (COM and NO), the two magnetizable reeds are magnetized to different polarities, and the two magnetizable reeds are attracted to realize conduction, so that signal switching is completed; when the magnetic field is far away from the reed pipe, two magnetizable reeds demagnetize, one magnetizable reed (COM) is connected with a non-magnetic conductive reed (NC) under the action of self elasticity, and signal restoration is completed.

Please refer to fig. 3, which is a schematic diagram illustrating a mounting structure of the valve proximity switch shown in fig. 2. The valve proximity switch further comprises at least four connecting pieces and at least two wires, the first output end of the first switch unit is connected with one end of the first wire through the first connecting piece, the input end of the second switch unit is connected with the other end of the first wire through the second connecting piece, the second output end of the first switch unit is connected with one end of the second wire through the third connecting piece, and the input end of the third switch unit is connected with the other end of the second wire through the fourth connecting piece. The switch units can be connected through lead wires and copper strip cold-pressing connectors. The first output 111 of the first switching unit 110 may be connected to the input 122 of the second switching unit 120 by means of copper strip cold-pressed connections and wires 140, for example.

Fig. 4 is a schematic structural diagram of a mounting seat in the valve proximity switch shown in fig. 3. Referring to fig. 4, it can be seen that the valve proximity switch may further include a mounting seat 150, which may be a cylinder, where three mounting holes 151 penetrate through the mounting seat 150 along the direction of the axis, each mounting hole 151 is correspondingly provided with a switch unit, an input end of each switch unit is located in a mounting hole on one side of the mounting seat, and a first output end and a second output end of the switch unit are located in a mounting hole on the other side of the mounting seat.

The mounting seat may be in other forms such as a mounting plate for securing at least two switch units in the valve proximity switch.

It should be noted that two wire vias 152 may be disposed through the mounting hole 151, so that when each switch unit is located in the mounting seat 150, the wire 140 passes through the wire via 152, and the copper strip cold-pressed connector connects the wire 140 and each switch unit outside the mounting seat 150.

In one embodiment of the present utility model, the switching units are uniformly distributed with the axis of the mounting base 150.

It should be noted that, the switch units are uniformly distributed on the axis of the mounting base 150, so that each switch unit may be uniformly disposed in the mounting base 150, and the volume of the valve proximity switch may be smaller.

In an embodiment of the utility model, the material of the mounting seat is an insulating material.

It should be noted that, the mount pad can adopt high temperature resistant, irradiation resistant, nonmetallic material PEEK (polyether ether ketone) or ceramic that insulativity is high, on the one hand can improve valve proximity switch's high temperature tolerance and anti-radiation ageing performance, on the other hand also can play the mechanical protection effect to the glass seal tube, can reduce each switch unit and hang, shake, strike the mechanical damage even broken inefficacy that cause because of rubbing in installation, test, cycle life work.

In one embodiment of the present utility model, the first and second output terminals of the first switching unit 110, the input and second output terminals of the second switching unit 120, and the input and first output terminals of the third switching unit 130 may be set to a first length, and the input terminal of the first switching unit 110, the first output terminal of the second switching unit 120, and the second output terminal of the third switching unit 130 may be set to a second length, which is greater than the first length.

When the valve proximity switch is assembled, the input end and the first output end of the third switch unit, the input end and the second output end of the second switch unit, and the first output section and the second output end of the first switch unit need to be sheared and shortened to a first length so as to facilitate series connection and avoid the risk of false contact with other terminals; then placing the three switch units and the two wires into the mounting holes or the wire through holes of the mounting seat, respectively connecting the input end of the second switch unit with the left end of the first wire through the copper strip cold-pressing connecting piece, connecting the input end of the third switch unit with the left end of the second wire through the copper strip cold-pressing connecting piece, connecting the second output end of the first switch unit with the right end of the second wire through the copper strip cold-pressing connecting piece, and connecting the first output end of the first switch unit with the right end of the first wire through the copper strip cold-pressing connecting piece to complete circuit connection of the valve proximity switch shown in figure 3; and finally, bending the input end of the first switch unit, the second output end of the third switch unit and the first output end of the second switch unit by 90 degrees and intercepting a certain height to respectively serve as the input end, the second output end and the first output end of the valve proximity switch, wherein the bending direction and the intercepting height are required to be kept consistent, and the serial assembly can be conveniently installed and fixed on a circuit board.

In summary, the embodiment of the utility model provides a valve proximity switch, which at least includes two switch units, namely a first switch unit and a second switch unit, each switch unit at least includes an input end and a first output end, a normally open switch for sensing a magnet action is disposed between the input end and the first output end, wherein the first output end of the first switch unit is connected with the input end of the second switch unit, the input end of the first switch unit is the input end of the valve proximity switch, and the first output end of the second switch unit is the first output end of the valve proximity switch. By connecting the first switch unit with the second switch unit, control information can be output when the on-off states of the two switch units are the same, and the reliability of the valve proximity switch can be improved.

Fig. 5 is a schematic structural diagram of an induction device according to an exemplary embodiment of the present utility model. As can be seen with reference to fig. 5, the inductive device 500 may include:

at least two valve proximity switches (fig. 5 shows a case including the valve proximity switch shown in fig. 1) provided in any one of the embodiments are used for sensing a magnet, one of the valve proximity switches is a first sensing switch 510, the other valve proximity switch is a second sensing switch 520, a distance value between the first sensing switch 510 and the magnet 10 is a first distance value, a distance value between the second sensing switch 520 and the magnet 10 is a second distance value, and a difference value between the first distance value and the second distance value is greater than a preset value, and both the first sensing switch 510 and the second sensing switch 520 are sensing switches.

When the first inductive switch 510 senses the magnet 10, a normally open switch in the first inductive switch 510 is closed; when the second inductive switch 520 senses the magnet 10, a normally open switch in the second inductive switch 520 is closed.

It should be noted that, because the first inductive switch 510 and the second inductive switch 520 are not normally open switches at the same time, the operator needs to set the positions of the first inductive switch 510 and the second inductive switch 520 according to the magnetic fields of the magnets, and the first inductive switch 510 and the second inductive switch 520 may be disposed on two sides of the central axis of the magnet 10.

For example, the start-up of the nuclear power reactor may be classified into a cold start-up and a hot start-up, and the position of the induction switch may be set according to the control temperature. The first inductive switch can be a cold start inductive switch, the second inductive switch can be a hot start inductive switch, and the second inductive switch can be arranged at a position in the inductive device, which is closer to the magnet, according to the influence of temperature on the magnetic field of the magnet, and the first inductive switch is arranged at a position in the inductive device, which is farther from the magnet. Through set up first inductive switch and second inductive switch simultaneously on inductive device, can improve inductive device's suitability to nuclear island operating mode. The installation positions of the first inductive switch and the second inductive switch on the inductive device can be designed according to the strength of the triggering magnetic field and the high-temperature attenuation rate thereof.

Referring to fig. 6, a schematic structural diagram of an induction device according to another exemplary embodiment of the present utility model is shown. The inductive switch may comprise at least two valve proximity switches in the inductive device. That is, the first inductive switch 510 includes valve proximity switches 510a and 510b, and the second inductive switch 520 may include valve proximity switches 520a and 520b.

Please refer to fig. 7, which is a schematic diagram illustrating a connection relationship of a plurality of inductive switches in the inductive device shown in fig. 6. The input of the valve proximity switch in each of the sensing switches is connected to the input COM of the sensing device, i.e. the input of the valve proximity switches 510a, 510b, 520a and 520b may be connected to the input COM of the sensing device. The first output ends of the valve proximity switches 510a and 510b in the first inductive switch 510 are connected with the first normally open output end NO1 of the inductive device, and the first output ends of the valve proximity switches 520a and 520b in the second inductive switch 520 are connected with the second normally open output end NO2 of the inductive device.

In one embodiment of the present utility model, when the valve proximity switch includes a second output terminal, the second output terminals of the valve proximity switches 510a and 510b in the first sensing switch 510 are connected to the first normally closed output terminal NC1 of the sensing device, and the second output terminals of the valve proximity switches 520a and 520b in the second sensing switch 520 are connected to the second normally closed output terminal NC2 of the sensing device.

It should be noted that, four sets of valve proximity switches are designed in double parallel: the valve proximity switches 510a and 510b are connected in parallel to be cold start inductive switches, the valve proximity switches 520a and 520b are connected in parallel to be hot start inductive switches, and the two inductive switches 510 and 520 are connected in parallel to enter the circuit bus. For a single inductive switch, the output channel of a feedback signal is increased through the parallel valve proximity switch, on one hand, the contact resistance of the contact is reduced through the parallel shunt characteristic, and on the other hand, the failure of the whole inductive device caused by the phenomena of mechanical abrasion, fatigue aging, arc corrosion and the like of one valve proximity switch is avoided, the failure rate of the valve proximity switch of the nuclear power valve is reduced, and the stability of a nuclear power valve control system is improved. For different induction switches, the high-low temperature cold and hot starting general function is realized by connecting the induction switches in parallel to the signal circuit, and the applicability of single induction equipment to the working condition of the nuclear island is improved. Of particular note is the manner in which the double parallel design is installed: the valve proximity switches of the same induction switch are required to be installed in parallel and flush, the valve proximity switches of different induction switches are required to be installed at staggered intervals, the cold start induction switch is farther from the magnet, and the installation position is designed according to the strength of the triggering magnetic field and the high-temperature attenuation rate of the triggering magnetic field.

It should be noted that in each of the inductive switches, the number of the valve proximity switches may be greater, that is, a plurality of valve proximity switches may be connected in parallel in each inductive switch.

In the sensing device shown in fig. 6, the sensing device may further include a circuit board 530, the first sensing switch 510 is disposed on one side of the circuit board 530, and the second sensing switch 520 is disposed on the other side of the circuit board 530. The circuit board 530 may be a printed circuit board (PrintedCircuitBoard, PCB).

It should be noted that, the valve proximity switches in each induction switch are installed in parallel on the plane of the circuit board 530, the valve proximity switches in different induction switches are installed in a staggered manner in space, and the staggered distance is accurately designed according to the magnetic field intensity difference of the magnet under different temperature working conditions (such as a high-temperature working condition and a low-temperature working condition) of the nuclear island.

For example, in the sensing device shown in fig. 6, four valve proximity switches (valve proximity switch 510a, valve proximity switch 510b, valve proximity switch 520a, valve proximity switch 520b, respectively), one magnet 10, and one circuit board 530 may be included. The valve proximity switch 520a and the valve proximity switch 520b can be used as hot start induction switches, the other two valve proximity switches 510a and the valve proximity switch 510b can be used as cold start induction switches, two valve proximity switches with the same function are arranged in parallel on the plane of the circuit board 530, two valve proximity switches with different functions are arranged in a staggered manner in space, and the staggered distance is accurately designed according to the magnetic field intensity difference of the magnet 10 under the high-temperature working condition and the low-temperature working condition of the nuclear island; the magnet 10 may be mounted on the axis of the sensing device with the valve proximity switch completing the contact actuation and valve position signal feedback when the magnet 10 is in proximity to the sensing device.

Fig. 8 is a schematic diagram of a circuit board in the induction device shown in fig. 6. Five phi 2 terminal holes p are formed in the rightmost side of the circuit board 530 for welding signal cables (a first normally open output end NO1, a second normally open output end NO2, a first normally closed output end NC1, a second normally closed output end NC2 and an input end COM of the sensing device shown in fig. 7, an arrangement sequence of the terminal holes p can be determined according to an actual circuit wiring), 12 phi 1.5 pin welding holes m are uniformly distributed in two sides of the circuit board 530 for welding and fixing a valve proximity switch on the circuit board 530, four phi 3 internal part fixing holes n can be formed in the middle of the circuit board 530, and the internal part fixing holes n can be connected through screws to realize installation and fixation of an internal structure of the sensing device and a valve proximity switch installation seat or a supporting seat.

Exemplary, as shown in fig. 9, a schematic structural diagram of an induction device according to another exemplary embodiment of the present utility model is shown. Wherein, the switch units of the same functional group can be uniformly distributed around the ring, wherein the hot start inductive switches 520a and 520b can be positioned at the inner ring, the cold start inductive switches 510a and 510b can be positioned at the outer ring, the connection relation of the switch units in the valve proximity switches in each inductive switch can be referred to as fig. 2, the two are arranged at staggered intervals in the axial direction of the magnet (as shown in fig. 10), the cold press connecting piece of the copper belt and the lead wire can be connected with each inductive switch according to the circuit schematic diagram shown in fig. 7, the magnet is coaxially arranged with the center of the inductive device, and the utilization rate of the inner space of the inductive device and the convenience of product installation, debugging and maintenance can be improved while the same functional characteristics as the inductive device shown in fig. 6 are realized.

In one embodiment of the utility model, all of the valve proximity switches are parallel to each other.

In summary, an embodiment of the application provides an induction device, where the induction device includes at least two valve proximity switches provided in any one of the embodiments, where the valve proximity switch is used for sensing a magnet, one of the valve proximity switches is a first induction switch, the other valve proximity switch is a second induction switch, a distance value between the first induction switch and the magnet is a first distance value, a distance value between the second induction switch and the magnet is a second distance value, a difference value between the first distance value and the second distance value is greater than a preset value, and both the first induction switch and the second induction switch are induction switches; when the first inductive switch senses the magnet, a normally open switch in the first inductive switch is closed; when the second inductive switch senses the magnet, a normally open switch in the second inductive switch is closed. That is, the first inductive switch and the second inductive switch can correspond to different temperature working conditions, and control over different temperature working conditions is achieved by arranging one inductive device. The space utilization of the induction device can be improved.

The embodiment of the utility model also provides a nuclear island starting control system, which can comprise:

the magnet and the induction device provided by any of the embodiments above may be arranged on one side of the output end of the induction device.

The above embodiments are merely illustrative of the principles of the present utility model and its effectiveness, and are not intended to limit the utility model. Modifications and variations may be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the utility model. It is therefore intended that all equivalent modifications and changes made by those skilled in the art without departing from the spirit and technical spirit of the present utility model shall be covered by the appended claims.

Claims (10)

1. A valve proximity switch, comprising:

each switch unit at least comprises an input end and a first output end, and a normally open switch for inducing the action of a magnet is arranged between the input end and the first output end; the first output end of the first switch unit is connected with the input end of the second switch unit, the input end of the first switch unit is the input end of the valve proximity switch, and the first output end of the second switch unit is the first output end of the valve proximity switch.

2. The valve proximity switch according to claim 1, further comprising at least two connectors and at least one wire, wherein a first output terminal of the first switching unit is connected to one end of the wire through one of the connectors, and an input terminal of the second switching unit is connected to the other end of the wire through the other of the connectors.

3. The valve proximity switch according to claim 1, further comprising at least a third switching unit, each switching unit further comprising a second output, a normally closed switch for sensing a magnet action being arranged between the input and the second output, the second output of the first switching unit being connected to the input of the third switching unit, the second output of the third switching unit being the second output of the valve proximity switch.

4. A valve proximity switch according to claim 3, further comprising at least four connectors and at least two wires, wherein a first output of the first switching unit is connected to one end of the first wire via a first connector, an input of the second switching unit is connected to the other end of the first wire via a second connector, a second output of the first switching unit is connected to one end of the second wire via a third connector, and an input of the third switching unit is connected to the other end of the second wire via a fourth connector.

5. A valve proximity switch according to claim 3, wherein the first and second outputs of the first switching unit, the input and second outputs of the second switching unit, the input and first outputs of the third switching unit are provided with a first length, and the input of the first switching unit, the first output of the second switching unit and the second output of the third switching unit are provided with a second length, the second length being larger than the first length.

6. An inductive device, comprising:

at least two valve proximity switches according to any one of claims 1-5, wherein the valve proximity switches are used for sensing a magnet, one of the valve proximity switches is a first sensing switch, the other valve proximity switch is a second sensing switch, a distance value between the first sensing switch and the magnet is a first distance value, a distance value between the second sensing switch and the magnet is a second distance value, a difference value between the first distance value and the second distance value is larger than a preset value, and the first sensing switch and the second sensing switch are both sensing switches;

when the first inductive switch senses the magnet, a normally open switch in the first inductive switch is closed; when the second inductive switch senses the magnet, a normally open switch in the second inductive switch is closed.

7. The inductive device of claim 6, wherein each of said inductive switches comprises at least two of said valve proximity switches, wherein an input of each of said valve proximity switches is connected to an input of said inductive device, wherein a first output of each of said valve proximity switches in said first inductive switch is connected to a first normally open output of said inductive device, and wherein a first output of each of said valve proximity switches in said second inductive switch is connected to a second normally open output of said inductive device.

8. The sensing apparatus of claim 6, wherein all of said valve proximity switches are parallel to each other.

9. The inductive device of claim 6, further comprising a circuit board, wherein said first inductive switch is disposed on one side of said circuit board and said second inductive switch is disposed on the other side of said circuit board.

10. A nuclear island start-up control system, comprising: a magnet and an inductive device as claimed in any one of claims 6 to 9, the magnet being arranged on one side of the output end of the inductive device.