Blowout panel forced opening system

Abstract

To prevent an overload of an electric motor upon moving a blowout panel.SOLUTION: A forced opening system 100 comprises: a blowout panel 16 that is installed in an opening 13 of a building (a nuclear reactor building 11); a shielding body (a shielding door 14) that moves along an outer wall 12 of the building; a forced opening mechanism 20 that causes the blowout panel to move to a more outer side retreat position than a closed position when closing the shielding body; a detection unit (a winding end limit switch 52b) that detects a movement of the blowout panel to an outward position rather than the closed position; and a control unit 50 that controls an operation of an electric motor (an electrically-driven winch 21) of the forced opening mechanism. The control unit is configured to cause the blowout panel to move to the retreat position in a state where a torque of the electric motor is controlled below an upper limit value load, while limiting an actuation time of the electric motor.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a forced opening system for a blow-out panel.

Background Art

[0002] In existing nuclear power plants, blow-out panels are installed to release the pressure generated inside the reactor building due to some factor to the outside of the building. In recent years, in order to open the blow-out panel and move it to a predetermined evacuation position, a forced opening mechanism that forcibly opens the blow-out panel by connecting the blow-out panel to a wire rope or the like and pulling it by an electric motor such as an electric winch (for example, see Patent Document 1) has been increasingly installed. The prior art disclosed in Patent Document 1 stops the winding of the electric winch when the winding end limit switch turns ON when a certain winding amount is reached when the wire rope is wound by the electric winch (electric motor).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The prior art disclosed in Patent Document 1 has a problem that the electric motor may be overloaded when moving the blow-out panel, as described below.

[0005] For example, a blowout panel may swing like a pendulum when open. In this case, the wire rope may behave irregularly and exceed the drum groove of the electric winch, potentially causing a winding error when the wire rope is wound up in this state. If a winding error occurs, the winding length will be irregular, which may prevent the winding end limit switch from turning on. As a result, there is a concern that the electric winch may wind up more wire rope than necessary, leading to an overloaded operation.

[0006] The present invention was made to solve the aforementioned problems, and its main objective is to provide a forced opening system for a blowout panel that prevents the electric motor from becoming overloaded when moving the blowout panel. [Means for solving the problem]

[0007] To achieve the above objective, the present invention provides a forced opening system for a blowout panel, comprising: a blowout panel installed in an opening of a building; a shielding body that moves along the outer wall of the building; a forced opening mechanism that moves the blowout panel to a retracted position outside the closed position when the shielding body is closed; a detection unit that detects when the blowout panel has moved outside the closed position; and a control unit that controls the operation of the electric motor of the forced opening mechanism, wherein the control unit moves the blowout panel to the retracted position while limiting the operating time of the electric motor and torque-controlled the traction load of the electric motor to be below an upper limit load. The above-mentioned upper limit load satisfies the conditions that it is equal to or greater than the rated load of the forced release mechanism and that it is equal to or less than the limit load of the equipment to which it is wound. This will be the structure. Other methods will be described later. [Effects of the Invention]

[0008] According to the present invention, it is possible to prevent the electric motor from entering an overloaded operating state when moving the blowout panel. [Brief explanation of the drawing]

[0009] [Figure 1]This is a diagram illustrating the configuration of a forced opening system for a blowout panel according to an embodiment of the system. [Figure 2] This is a schematic diagram of the control unit in a forced opening system for a blowout panel. [Figure 3] This is an explanatory diagram of the torque setting value for the forced release mechanism. [Figure 4] This is a flowchart showing the operation of the forced release system. [Modes for carrying out the invention]

[0010] The present invention also aims to provide a forced release system that moves the blowout panel to a predetermined retracted position relatively stably, even when the winding end limit switch is not turned ON. Furthermore, the present invention also aims to provide a forced release system that suppresses excessive stress on the wire rope and the equipment at the winding end.

[0011] Hereinafter, embodiments of the present invention (hereinafter referred to as "these embodiments") will be described in detail with reference to the drawings. Note that each figure is merely a schematic representation to the extent necessary for a thorough understanding of the present invention. Therefore, the present invention is not limited to the illustrated examples. Furthermore, in each figure, common or similar components are denoted by the same reference numerals, and their redundant descriptions are omitted.

[0012] <Configuration of the forced release system> The configuration of the blowout panel forced opening system 100 according to this embodiment will be described below with reference to Figure 1. Figure 1 is a configuration diagram of the blowout panel forced opening system 100 according to this embodiment.

[0013] As shown in Figure 1, the outer wall 12 of the reactor building 11 is provided with an opening 13 that opens to the outside. A blowout panel 16, shown by the dashed line in Figure 1, is fastened to the opening 13 by clips (not shown). The blowout panel 16 normally keeps the opening 13 closed. When the internal pressure of the reactor building 11 rises, the pressure causes the clips to detach, opening the blowout panel 16 and releasing the pressure and hydrogen inside the reactor building 11.

[0014] Furthermore, a shielding door 14 and a closing device 15 are provided on the outside of the outer wall 12 of the reactor building 11. The shielding door 14 is a shielding body for closing off the space inside the reactor building 11 and is configured to slide along the outer wall 12. The closing device 15 is a device that closes the opening 13, which is opened when the blowout panel 16 is opened, by sliding the shielding door 14.

[0015] Connecting members 19 are provided at relatively upper and lower positions on the outer wall side of the blowout panel 16. A chain 17 is attached to the connecting member 19 located relatively upper on the blowout panel 16. The chain 17 is attached to the end of a support member 18 located on the outside of the reactor building 11. A wire rope 22 is attached to the connecting member 19 located near the lower end of the blowout panel 16. The wire rope 22 is attached to the drum 21a of the electric winch 21, which will be described later. The electric winch 21 is the motor of the forced release mechanism 20, which will be described later. The blowout panel 16, chain 17, support member 18, and connecting members 19 constitute the equipment 30 to which the blowout panel 16 is wound.

[0016] When an event occurs that causes the blowout panel 16 to open, the opened blowout panel 16 often remains in an intermediate position. Therefore, the forced opening system 100 pulls the blowout panel 16 with the wire rope 22 by driving the electric winch 21 of the forced opening mechanism 20. As a result, the blowout panel 16 is forcibly opened and moves to the position shown by the solid line in Figure 1. At this time, the blowout panel 16 is suspended via the chain 17 from the end of the support member 18 provided on the outside of the reactor building 11. The winding end limit switch 52b detects the completion of winding the wire rope 22.

[0017] The wire rope 22 is wound onto the drum 21a of the electric winch 21. The forced release system 100 is configured to detect a certain amount of winding of the wire rope 22 using a winding end limit switch 52b. The winding end limit switch 52b functions as a detection unit that detects when the blowout panel 16 has moved to a retracted position outside the position where the shielding door 14 passes through (the closed position when the shielding body is closed) due to the operation of the forced release mechanism 20. As the winding end limit switch 52b, a rotation sensor that detects the rotation angle of the drum 21a of the electric winch 21 can be used. The winding end limit switch 52b detects the amount of winding of the wire rope 22 based on the winding angle θ of the drum 21a. The winding angle θ of the drum 21a is calculated based on the rotation angle of the drum 21a of the electric winch 21 detected by the winding end limit switch 52b. The forced release system 100 stops the winding of the electric winch 21 when the winding angle θ of the drum 21a reaches a preset angle, by turning on the winding end limit switch 52b.

[0018] When a snarling event occurs, the wire rope 22 can be wound up beyond the set position of the take-up end limit switch 52b, and the blow-out panel 16 stops at a position deviated from the predetermined retracted position, and excessive loads may be applied to the forced release mechanism 20 and the equipment 30 at the take-up end. Therefore, the electric winch 21 of the forced release mechanism 20 operates according to the flowchart of FIG. 4. The details of the operation will be described in the chapter <Operation of the Forced Release System> below. Basically, the forced release mechanism 20 automatically stops with the signal of the take-up end limit switch 52b as an interlock. However, when the take-up end limit switch 52b is not detected due to a snarling event or the like, the torque setting value shown in FIG. 3 is set in the inverter 51a, and the take-up time is set in the congestion monitoring timer 52a. Thereby, the winding is maintained at the torque setting value, and the electric winch 21 automatically stops with the take-up time set by the congestion monitoring timer 52a as an interlock. The congestion monitoring timer 52a starts measuring time at the timing when the forced release mechanism 20 is activated and stops the forced release mechanism 20 at the set time. The details of the torque setting value will be described in the chapter <Outline of Torque Setting Value> below.

[0019] FIG. 2 is a schematic configuration diagram of the control unit 50 of the forced release system 100. As shown in FIG. 2, the control unit 50 of the forced release system 100 includes a field panel 51 and a monitoring operation panel 52. The field panel 51 is a device that directly controls the electric winch 21. The monitoring operation panel 52 is a device that gives instructions to the field panel 51. The field panel 51 is provided with an inverter 51a for torque control of the electric winch 21. Further, the monitoring operation panel 52 is provided with a congestion monitoring timer 52a for monitoring the congestion of the winding operation of the wire rope 22 and a take-up end limit switch 52b for detecting a certain take-up amount of the wire rope 22.

[0020] <Outline of Torque Setting Value> FIG. 3 is an explanatory diagram of the torque setting value of the forced release mechanism 20. In the example shown in FIG. 3, the load required to open the blowout panel 16, the rated load of the forced release mechanism 20, the limit load of the winding destination device 30, and the maximum load value during overload of the motor (electric winch 21) are shown in order from the smallest value. As shown in FIG. 3, the torque setting value is a value that takes into account the error of torque control, with the load required to open the blowout panel 16 set as the lower limit load value and the limit load of the winding destination device 30 set as the upper limit load value. More preferably, the upper limit load value (torque upper limit load value) of the torque setting value should satisfy the conditions that it is not less than the rated load of the forced release mechanism 20 and not more than the limit load of the winding destination device 30. The torque upper limit load value is set according to the maximum load value during overload of the motor (electric winch 21). In this embodiment, the forced release mechanism 20 will be described as operating within an error range from - error Min to + error Max with respect to the upper limit load value of the torque setting value.

[0021] <Operation of the forced release system> FIG. 4 is a flowchart showing the operation of the forced release system 100. Here, the case where the operator operates the monitoring operation panel 52 to activate the forced release mechanism 20 when the blowout panel 16 is opened will be described. However, the forced release system 100 may be configured such that when the blowout panel 16 is opened, the control unit 50 activates the forced release mechanism 20 without the operator operating the monitoring operation panel 52.

[0022] In a nuclear power plant, when the internal pressure of the reactor building 11 increases due to some factor, a clip (not shown) that holds the blowout panel 16 at the opening 13 is disengaged by the pressure, the blowout panel 16 opens, and the pressure and hydrogen inside the reactor building 11 are released. At that time, the operator operates the monitoring operation panel 52 to activate the forced release mechanism 20.

[0023] At this time, as shown in Figure 4, the control unit 50 of the forced release system 100 accepts an operation from the operator via the monitoring control panel 52 (step S110). Then, the control unit 50 activates the congestion monitoring timer 52a and sets a time limit to restrict the operating time of the electric winch 21 (motor) of the forced release mechanism 20 (step S120).

[0024] The "time limit" is the maximum time from the start to the stop of the forced release mechanism 20. The "time limit" can be set in advance on the monitoring control panel 52. Here, the "time limit" is explained as being the time obtained by adding an arbitrary amount of time (a few minutes) to the time scheduled when the winding end limit switch 52b is turned ON (scheduled ON time). The "scheduled ON time" is the time required for the electric winch 21 to wind up a certain amount of wire rope 22 at the initial load (the time required to move the blowout panel 16 to a predetermined position), and is determined according to the winding speed of the wire rope 22 by the electric winch 21. The "scheduled ON time" can be set in advance on the monitoring control panel 52. Here, the "scheduled ON time" is explained as being ((certain amount of wire rope 22 wound up) / (winding speed of wire rope 22 by the electric winch 21) + (allowable operating time α)). Here, "certain amount of wire rope 22 wound up" means the amount of winding required to move the blowout panel 16 to a predetermined retracted position. Furthermore, the "predetermined retraction position" refers to a position outside the closed position of the shielding door 14 when it is closed. The retraction position is such that the blowout panel 16 does not obstruct the movement of the shielding door 14 when it slides. The "allowable operation time α" is a settable time of several minutes.

[0025] Next, the control unit 50 activates the forced release mechanism 20 (step S130). At this time, the electric winch 21 of the forced release mechanism 20 pulls the wire rope 22 with the initial load. The initial load is a value greater than the torque upper limit load (see Figure 3).

[0026] Next, the control unit 50 determines whether the winding end limit switch 52b was turned ON within the scheduled ON time (step S140).

[0027] In step S140, if it is determined that the winding end limit switch 52b is not turned ON within the scheduled ON time ("No"), the blowout panel 16 will swing like a pendulum, and the wire rope 22 may be behaving irregularly. If this condition persists for a relatively long time, the wire rope 22 will exceed the groove (drum groove) of the drum 21a of the electric winch 21, and winding the wire rope in this state will cause a winding error. Therefore, in this case, to prevent a winding error from occurring, the control unit 50 starts torque control by the inverter 51a within the time limit measured by the congestion monitoring timer 52a (step S150). In torque control, the forced release system 100 moves the blowout panel 16 by pulling the wire rope 22 while controlling the traction load of the electric winch 21 with the inverter 51a to a torque upper limit load smaller than the initial setting load.

[0028] After step S150, if the winding end limit switch 52b is turned ON, or if the congestion monitoring timer 52a determines that the time limit has elapsed, the control unit 50 stops the congestion monitoring timer 52a (step S160).

[0029] If, in step S140, it is determined that the winding end limit switch 52b has been turned ON within the scheduled ON time ("Yes"), or after step S160, the control unit 50 stops the forced release mechanism 20 (step S170). This completes the series of processes.

[0030] If, in step S170, the forced release mechanism 20 stops while the wire rope 22 has exceeded the drum groove of the electric winch 21, the operator operates the monitoring control panel 52 to rotate the drum 21a of the electric winch 21 in the reverse direction to return the wire rope 22 to the drum groove of the electric winch 21. After this, the operator operates the monitoring control panel 52 to rotate the drum 21a of the electric winch 21 in the forward direction to pull the wire rope 22 and move the blowout panel 16 to the predetermined position.

[0031] <Main features of the forced release system> (1) As shown in Figure 1, the forced opening system 100 according to this embodiment includes a blowout panel 16 installed in an opening 13 of the reactor building 11, a shielding door 14 (shielding body) that moves along the outer wall 12 of the reactor building 11, a forced opening mechanism 20 that moves the blowout panel 16 to an outward position beyond the closed position when the shielding door 14 is closed, a winding end limit switch 52b (detection unit) that detects when the blowout panel 16 has moved to a retracted position outside the closed position, and a control unit 50 that controls the operation of the electric winch 21 (motor) of the forced opening mechanism 20. The control unit 50 moves the blowout panel 16 to the retracted position while limiting the operating time of the electric winch 21 with a congestion monitoring timer 52a and torque-controlling the traction load of the electric winch 21 to be less than or equal to the upper limit load with an inverter 51a.

[0032] In this embodiment of the forced release system 100, the operating time of the electric winch 21 is limited by the congestion monitoring timer 52a, and the torque of the electric winch 21 is controlled by the inverter 51a to keep the traction load of the electric winch 21 below the torque upper limit, while the blowout panel 16 is moved to the forced release mechanism 20. Even if the blowout panel 16 were to swing like a pendulum between steps S130 and S150 in Figure 4, causing the wire rope 22 to exceed the drum groove of the electric winch 21, the traction load of the electric winch 21 is controlled to be below the torque upper limit, and the operating time of the electric winch 21 is limited to within the time limit. Therefore, the forced release system 100 can prevent the electric winch 21 from winding up the wire rope 22 more than necessary. This prevents excessive load from being placed on the wire rope and the equipment to which it is wound. As a result, the electric motor (electric winch 21) can not be operated under an overload condition when moving the blowout panel 16. Furthermore, even if the winding end limit switch does not turn ON within the scheduled ON time, the wire rope 22 is pulled until the time limit expires, thereby moving the blowout panel 16 to a predetermined retracted position in a relatively stable manner.

[0033] (2) As shown in Figure 3, the upper limit load should satisfy the conditions that it is equal to or greater than the rated load of the forced release mechanism 20 and that it is equal to or less than the limit load of the winding destination equipment 30.

[0034] The forced release system 100 according to this embodiment can move the blowout panel 16 to a predetermined retracted position relatively stably, even when a winding event occurs.

[0035] (3) The control unit 50 may operate the forced opening mechanism 20 to guide the blowout panel 16 to a position that does not obstruct the movement of the shielding door 14 and to restrain it in that position.

[0036] In this embodiment of the forced release system 100, even when a winding disorder occurs, the blowout panel 16 can be moved to a predetermined retracted position in a relatively stable manner, thereby preventing excessive stress on the wire rope 22 and the equipment to which it is wound.

[0037] (4) The control unit 50 may set the operating time limit for the electric winch 21 to satisfy the conditions that the time is longer than the time required to restrain the blowout panel 16 with the forced opening mechanism 20, and that the time is less than or equal to the time required for the shielding door 14 to be fully closed.

[0038] In this embodiment of the forced release system 100, even when a winding disorder occurs, the occurrence of an overload operation condition caused by the electric winch 21 (motor) of the forced release mechanism 20 winding the wire rope 22 more than necessary can be reduced.

[0039] As described above, the forced opening system 100 according to this embodiment prevents the electric motor (electric winch 21) from becoming overloaded when moving the blowout panel 16.

[0040] The present invention is not limited to the embodiments described above, and includes various modifications. For example, the embodiments described above are described in detail for the purpose of clearly illustrating the present invention, and are not necessarily limited to those having all the configurations described. Furthermore, it is possible to replace some of the configurations of the embodiments with other configurations, and it is also possible to add other configurations to the configurations of the embodiments. In addition, it is possible to add, delete, or replace some of the configurations of each configuration with other configurations. [Explanation of Symbols]

[0041] 11. Reactor building (building) 12 Exterior Walls 13 Opening 14. Shielding door (shield) 15 Closing device 16 Blowout Panel 17 chain 18 Support Member 19 Connecting member 20 Forced opening mechanism 21 Electric winch (motorized motor) 21a Drum 22 Wire rope 30 equipment 50 Control Unit 51 On-site board 51a Inverter 52 Monitoring operation panel 52a Traffic congestion monitoring timer 52b Winding end limit switch (detection unit) 100 Forced Release System θ Winding angle

Claims

1. A blowout panel installed at the opening of the building, A shielding body that moves along the outer wall of the aforementioned building, A forced opening mechanism that moves the blowout panel to an external position beyond the closed position when the shielding body is closed, A detection unit that detects when the blowout panel moves to a retracted position outside the closed position, The system comprises a control unit that controls the operation of the electric motor of the forced release mechanism, The control unit moves the blowout panel to the retracted position while limiting the operating time of the electric motor and controlling the torque of the electric motor to keep the traction load below the upper limit load. The aforementioned upper limit load satisfies the conditions that it is equal to or greater than the rated load of the forced release mechanism, and that it is equal to or less than the limit load of the equipment to which it is wound. A forced opening system for blowout panels, characterized by the following features.

2. In the forced opening system for the blowout panel according to claim 1, The control unit operates the forced release mechanism to guide the blowout panel to a position that does not obstruct the movement of the shielding body and to restrain it in that position. A forced opening system for blowout panels, characterized by the following features.

3. In the forced opening system for the blowout panel according to claim 1, The control unit sets the operating limit time of the electric motor such that it satisfies the conditions of being at least the time required to restrain the blowout panel in the forced opening mechanism, and being at least the time required for the shielding body to be fully closed. A forced opening system for blowout panels, characterized by the following features.

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