A redundant electrical overspeed protection device for the speed of a nuclear power plant steam-driven auxiliary feedwater pump

Abstract

The invention discloses a redundant electrical overspeed protection device for the speed of a steam-driven auxiliary water supply pump in a nuclear power plant, comprising a first-way speed sensor group, a speed signal optimization device, a speed switch, a protection relay, a first-way tripping solenoid valve, a main control room speed display device, a first-way speed protection reliable power supply unit, a main control room cabinet tripping protection button, a local cabinet tripping protection button, a pump body manual lever tripping mechanical protection, a mechanical protection connecting rod, a conical valve, a mechanical protection reset solenoid driver, a second-way speed sensor group, a multi-way signal processor, a protection relay, a second-way tripping solenoid valve, a second-way speed protection reliable power supply unit and a steam release pipeline. Its beneficial effect is that two independent redundant electrical overspeed automatic protection systems, as well as an emergency stop button and a lever are set, which can actively prevent the protection system from being paralyzed and unavailable due to a single device failure.

Description

Technical Field

[0001] The invention belongs to the field of steam-driven auxiliary feedwater pump control and protection, and in particular relates to a redundant electrical overspeed protection device for the rotation speed of a steam-driven auxiliary feedwater pump in a nuclear power plant. Background Art

[0002] The overspeed protection device of the existing nuclear power plant steam-driven auxiliary feedwater pump was originally designed with two sets of overspeed protection devices. One set is an electrical overspeed protection device, the principle of which is to open the solenoid valve through an electrical signal, so that the back pressure of the main steam valve is reduced to atmospheric pressure, the main steam valve is closed, and the steam-driven auxiliary pump is shut down; the other set is a mechanical overspeed protection device, the principle of which is that the overspeed hammer hits the mechanical tripping device under the action of centrifugal force, the mechanical tripping device is actuated, the conical valve is opened, the back pressure of the main steam valve is reduced to atmospheric pressure, the main steam valve is closed, and the steam-driven auxiliary pump is shut down.

[0003] Mechanical overspeed has the following disadvantages:

[0004] (1) The mechanical overspeed test needs to be conducted every 3 cycles (3C). During the test, personnel are required to operate and read data on-site in the steam-assisted pump room, which poses a great risk to personnel and industrial safety.

[0005] (2) During the mechanical overspeed process, the speed may exceed the designed speed, which may cause certain damage to the components of the steam-assisted pump equipment, including excessive speed causing excessive force on the components;

[0006] (3) The mechanical overspeed test process is complicated and requires closing the pump suction valve to unload the pump to create an overspeed condition. There is a high risk of equipment damage caused by human error. Experienced personnel are required to complete the test, and the overhaul critical path must be occupied. A normal test takes 8-24 hours. If the set speed of the overspeed hammer needs to be adjusted multiple times, the time will need to be further increased. Summary of the invention

[0007] The purpose of the present invention is to provide a redundant electrical overspeed protection device for the rotation speed of a nuclear power plant steam-driven auxiliary feedwater pump, which can effectively reduce the risk of damage to personnel and equipment and improve work efficiency.

[0008] The technical scheme of the present invention is as follows: a redundant electrical overspeed protection device for the speed of a steam-driven auxiliary feedwater pump in a nuclear power plant, comprising a first speed sensor group, a speed signal optimization device, a speed switch, a first protection relay, a first tripping solenoid valve, a speed display device in a main control room, a first speed protection reliable power supply unit, a main control room cabinet tripping protection button, a local cabinet tripping protection button, a pump body manual lever tripping mechanical protection, a mechanical protection connecting rod, a conical valve, a mechanical protection reset solenoid driver, a second speed sensor group, a multi-channel signal processor, a second protection relay, a second tripping solenoid valve, a second speed protection reliable power supply unit and a steam release pipeline;

[0009] The first speed protection reliable power supply unit is respectively connected to the first speed sensor group, the speed signal optimization device, the speed switch, the first protection relay and the first tripping solenoid valve and supplies power to them, the first speed sensor group is connected to the speed signal optimization device, the speed signal optimization device and the main control room speed display device are respectively connected to the speed switch, the speed switch, the main control room cabinet tripping protection button and the local cabinet tripping protection button are respectively connected to the first protection relay, the first protection relay is connected to the first tripping solenoid valve, and the first tripping solenoid valve is connected to the steam release pipeline;

[0010] The pump body manual lever tripping mechanical protection and the mechanical protection reset electromagnetic driver are respectively connected to the mechanical protection connecting rod, the mechanical protection connecting rod is connected to the cone valve, and the cone valve is connected to the steam discharge pipeline;

[0011] The second speed protection reliable power supply unit is respectively connected to the second speed sensor group, the multi-channel signal processor, the second protection relay and the second tripping solenoid valve to supply power to them;

[0012] The second speed sensor group is connected to a multi-channel signal processor, and the multi-channel signal processor is connected to a second protection relay;

[0013] The second protection relay is connected to the second tripping solenoid valve;

[0014] The second tripping solenoid valve is connected to the steam release pipeline.

[0015] The beneficial effects of the present invention are:

[0016] (1) The present invention is provided with two independent redundant electrical overspeed automatic protection systems, as well as an emergency stop button and a lever, which can actively prevent the protection system from being paralyzed and unavailable due to a single device failure.

[0017] (2) Each automatic protection of the present invention adopts a multi-sensor signal priority logic to ensure that the protection fails or malfunctions caused by a single-point failure of the speed sensor, thereby improving the reliability of the system.

[0018] (3) The present invention adopts two independent redundant power supply lines and tripping solenoid valves to avoid the overspeed protection function being unavailable due to abnormalities of a single power supply and pipeline.

[0019] (4) The present invention can replace the traditional fly hammer overspeed protection, effectively avoid the disadvantages of the fly hammer, and improve work efficiency.

[0020] (5) The system cost of the present invention is relatively low, and multiple fault prevention can be achieved with simple configuration. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram of a redundant electrical overspeed protection device for the rotation speed of a nuclear power plant steam-driven auxiliary feedwater pump provided by the present invention.

[0022] In the figure: 1 the first speed sensor group, 2 the speed signal optimization device, 3 the speed switch, 4 the first protection relay, 5 the first tripping solenoid valve, 6 the speed display device in the main control room, 7 the first speed protection reliable power supply unit, 8 the main control room cabinet tripping protection button, 9 the local cabinet tripping protection button, 10 the pump body manual lever tripping mechanical protection device, 11 the mechanical protection connecting rod, 12 the conical valve, 13 the mechanical protection reset solenoid driver, 14 the second speed sensor group, 15 the multi-channel signal processor, 16 the second protection relay, 17 the second tripping solenoid valve, 18 the second speed protection reliable power supply unit, 19 the steam release pipeline. DETAILED DESCRIPTION

[0023] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] The invention provides a redundant electrical overspeed protection device for the rotation speed of a pneumatic auxiliary feedwater pump in a nuclear power plant, which mainly includes two independent redundant rotation speed measurements and electrical overspeed protection tripping, a local pump body manual lever protection tripping, a local cabinet manual tripping button, and a main control room manual tripping button device.

[0025] like Figure 1 As shown, a redundant electrical overspeed protection device for the speed of a steam-driven auxiliary feedwater pump in a nuclear power plant includes a first speed sensor group 1, a speed signal optimization device 2, a speed switch 3, a first protection relay 4, a first tripping solenoid valve 5, a main control room speed display device 6, a first speed protection reliable power supply unit 7, a main control room cabinet tripping protection button 8, an on-site cabinet tripping protection button 9, a pump body manual lever tripping mechanical protection 10, a mechanical protection connecting rod 11, a conical valve 12, a mechanical protection reset solenoid driver 13, a second speed sensor group 14, a multi-channel signal processor 15, a second protection relay 16, a second tripping solenoid valve 17, a second speed protection reliable power supply unit 18, and a steam release pipeline 19.

[0026] Among them, the first speed protection reliable power supply unit 7 is respectively connected to the first speed sensor group 1, the speed signal optimization device 2, the speed switch 3, the first protection relay 4 and the first tripping solenoid valve 5 and supplies power to them, the first speed sensor group 1 is connected to the speed signal optimization device 2, the speed signal optimization device 2 and the main control room speed display device 6 are respectively connected to the speed switch 3, the speed switch 3, the main control room cabinet tripping protection button 8 and the local cabinet tripping protection button 9 are respectively connected to the first protection relay 4, the first protection relay 4 is connected to the first tripping solenoid valve 5, and the first tripping solenoid valve 5 is connected to the steam release pipeline 19.

[0027] The pump body manual lever tripping mechanical protection 10 and the mechanical protection reset electromagnetic driver 13 are respectively connected to the mechanical protection connecting rod 11, the mechanical protection connecting rod 11 is connected to the cone valve 12, and the cone valve 12 is connected to the steam release pipeline 19.

[0028] The second speed protection reliable power supply unit 18 is respectively connected to the second speed sensor group 14, the multi-channel signal processor 15, the second protection relay 16 and the second tripping solenoid valve 17 and supplies power to them. The second speed sensor group 14 is connected to the multi-channel signal processor 15, the multi-channel signal processor 15 is connected to the second protection relay 16, the second protection relay 16 is connected to the second tripping solenoid valve 17, and the second tripping solenoid valve 17 is connected to the steam release pipeline 19.

[0029] The specific models of the relevant components in the embodiments of the present invention are selected as follows:

[0030] The speed sensor group 1 can be a combination of one or two speed sensors, and the speed sensor of Electro Sensors 1101 or Jiangsu Lihe Instrument Control Technology Co., Ltd. ZH3200N is selected; the speed signal optimization device 2 uses Woodward505 speed regulator; the speed switch 3 uses Electro Sensors TR400; the first protection relay 4 uses a general relay with nuclear grade certification, and the first trip solenoid valve 5 uses Target Rock V2500-20 valve, or Anshan Solenoid Valve Co., Ltd. HZB1GG-15HX-III solenoid valve; the main control room speed display device 6 selects a universal secondary display head; the first speed protection reliable power supply unit 7 is mounted on the safe and reliable power supply of the power plant; the main control room cabinet tripping protection button 8 and the local cabinet tripping protection button 9 use certified universal protection buttons; the pump body manual lever tripping mechanical protection 10, mechanical protection connecting rod 11, and cone valve 12 follow the pump body manufacturer's design to ensure that the function is realized; the mechanical protection reset electromagnetic driver 13 uses Anshan Solenoid Valve Co., Ltd. DCQD-370; the second speed sensor group 14 is a combination of one to three speed sensors, and the model can be the same as the speed sensor group 1; the multi-channel signal processor 15 selects a universal nuclear-grade PLC or industrial computer equipment; the second protection relay 16 uses a universal relay with nuclear-grade certification; the second tripping solenoid valve 17 uses Target Rock's V2500-20 valve, or Anshan Solenoid Valve Co., Ltd.'s HZB1GG-15HX-III solenoid valve; the second speed protection reliable power supply unit 18 needs to be mounted to the power plant's safe and reliable power supply and has a different bus from the first power supply; the steam release pipeline 19 uses general nuclear-grade pipes.

[0031] The working process of the present invention is as follows:

[0032] Among them, the first speed sensor group 1 can adopt one speed sensor or two speed sensors. When one speed sensor is selected, the speed signal is sent to the speed switch 3 through the speed signal optimization device 2. In the speed switch, the speed signal is compared with the set speed setting value. When it is greater than the set value, the speed switch 3 outputs a high level; if two speed sensors are selected, from a safety perspective, among the two speed signals, the higher speed signal is preferred by the speed signal optimization device 2 to participate in the electrical tripping protection of the pump, and the selected speed signal is sent to the speed switch 3. In the speed switch, the speed signal is compared with the set speed setting value. When it is greater than the set value, the speed switch 3 outputs a high level.

[0033] After the control side coil of the first protection relay 4 receives the high level of the speed switch 3, the normally open point of the first protection relay 4 is closed, and the driving power is sent to the first tripping solenoid valve 5; after the first tripping solenoid valve 5 is energized, it jumps from the closed state to the open state, and the steam of the main steam valve of the pneumatic auxiliary water supply pump is bypassed and discharged through the first tripping solenoid valve 5 and the steam discharge pipeline 19 to achieve the purpose of shutdown.

[0034] When the first speed sensor group fails or there is other emergency situation, the control side coil of the first protection relay 4 is powered through the main control room cabinet tripping protection button 8 and the local cabinet tripping protection button 9, respectively, to ensure that the first tripping solenoid valve 5 is energized and the valve is opened to release pressure and shut down.

[0035] At the same time, the machine can also be shut down manually on the local pump body. First, the pump body manual lever tripping mechanical protection 10 is tapped, and the pump body manual lever tripping mechanical protection 10 is connected to the mechanical protection connecting rod 11, and the mechanical protection connecting rod 11 is connected to the valve stem of the conical valve 12. When the pump body manual lever tripping mechanical protection 10 is manually tapped, the mechanical linkage cone valve 12 is opened, and the steam of the main steam valve of the steam-driven auxiliary water supply pump is bypassed and discharged through the cone valve 12 and the steam discharge pipeline 19 to achieve the purpose of shutdown; when the manual lever is tapped, the electromagnetic driver 13 can be reset through the mechanical protection to remotely lift the manual lever tripping mechanical protection 10 to reset it to the normal position.

[0036] The first speed protection reliable power supply unit 7 provides a reliable power supply for the first speed protection related equipment and the reset electromagnetic driver 13 to ensure the safe and reliable operation of the equipment.

[0037] The second speed sensor group 14 consists of three speed sensors. The three speed sensor signals are preferably compared through the multi-channel signal processor 15, and the "second largest" signal among the three speed signals is compared with the set value. If it exceeds the set value, the multi-channel signal processor 15 outputs a high-level signal to the control side coil of the second protection relay 16. After the second protection relay 16 coil is energized, the normally open contact is closed, and the driving power is sent to the second tripping solenoid valve 17; after the second tripping solenoid valve 17 is energized, it jumps from a closed state to an open state, and the steam of the main steam valve of the pneumatic auxiliary water supply pump is bypassed and discharged through the second tripping solenoid valve 17 and the steam discharge pipeline 19 to achieve the purpose of shutdown. The second speed protection reliable power supply unit 18 provides an independent, safe and reliable power supply for the second speed protection related equipment to ensure stable operation of the equipment.

Claims

1. A redundant electrical overspeed protection device for the rotation speed of a steam-driven auxiliary feedwater pump in a nuclear power plant, characterized in that: It includes a first speed sensor group, a speed signal optimization device, a speed switch, a first protection relay, a first tripping solenoid valve, a speed display device in the main control room, a first speed protection reliable power supply unit, a main control room cabinet tripping protection button, a local cabinet tripping protection button, a pump body manual lever tripping mechanical protection, a mechanical protection connecting rod, a cone valve, a mechanical protection reset solenoid driver, a second speed sensor group, a multi-channel signal processor, a second protection relay, a second tripping solenoid valve, a second speed protection reliable power supply unit and a steam release pipeline; The first speed protection reliable power supply unit is respectively connected to the first speed sensor group, the speed signal optimization device, the speed switch, the first protection relay and the first tripping solenoid valve and supplies power to them, the first speed sensor group is connected to the speed signal optimization device, the speed signal optimization device and the main control room speed display device are respectively connected to the speed switch, the speed switch, the main control room cabinet tripping protection button and the local cabinet tripping protection button are respectively connected to the first protection relay, the first protection relay is connected to the first tripping solenoid valve, and the first tripping solenoid valve is connected to the steam release pipeline; The pump body manual lever tripping mechanical protection and the mechanical protection reset electromagnetic driver are respectively connected to the mechanical protection connecting rod, the mechanical protection connecting rod is connected to the cone valve, and the cone valve is connected to the steam discharge pipeline; The second speed protection reliable power supply unit is respectively connected to the second speed sensor group, the multi-channel signal processor, the second protection relay and the second tripping solenoid valve to supply power to them; The second speed sensor group is connected to a multi-channel signal processor, and the multi-channel signal processor is connected to a second protection relay; The second protection relay is connected to the second tripping solenoid valve; The second tripping solenoid valve is connected to the steam release pipeline.

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