A nuclear power plant evaporator seal blanking plate control device with redundant safety functions

Abstract

The present application belongs to the technical field of mechanical design, and particularly relates to a nuclear power plant evaporator sealing baffle control device with a redundant safety function. A manual switch valve, a filtering pressure reducing valve, a pressure gauge, an electrically controlled switch valve, a one-way valve A, an air storage tank, a pressure sensor A, a one-way valve B, an electromagnetic reversing valve, a precision pressure reducing valve, a throttle valve, a flow meter, a pressure sensor B and a filter are sequentially connected; the manual switch valve is connected with an air source, and the filter is connected with the sealing baffle. The safety redundancy performance is high, and the influence caused by common field problems such as loss of the main air source of the sealing baffle device and slight leakage of the sealing baffle air bag can be effectively eliminated.

Description

Technical Field

[0001] This invention belongs to the field of mechanical design technology, specifically relating to a control device for sealing and plugging plates of nuclear power plant evaporators with redundant safety functions. Background Technology

[0002] During the comprehensive in-service inspection of a nuclear power plant's refueling overhaul, in order to ensure that the in-service inspection of pressure vessels and the in-service inspection of steam generator heat transfer tubes are carried out simultaneously, sealing plugs need to be installed on the primary side water chamber of the steam generator and the main pipeline connection port to isolate the medium. Since the radiation dose level in the primary side water chamber of the steam generator is relatively high, the sealing reliability of the sealing plugs is very important.

[0003] The sealing plate typically employs a double-bladder sealing structure. The airbags, located on the side of the cup-shaped capsule of the sealing plate, are hollow annular structures. Based on the contact position between the airbags and the medium, they are divided into a dry chamber and a wet chamber. A certain pressure is injected into the dry and wet chambers through air pipes connected to the sealing plate, causing the airbags to expand. This expansion creates compression deformation on the inner wall of the main pipeline inlet of the steam generator, thus achieving a sealing effect. After inflation, the airbags form a sealed cavity between the dry and wet chambers; this cavity is called the intermediate chamber. The intermediate chamber needs to maintain a certain gas pressure to monitor the sealing status of the dry and wet chambers.

[0004] Traditional sealing plate control devices consist of an air supply line and corresponding pressure regulating valves and pressure gauges. After the sealing plate is installed, the main air source supplies air to the dry chamber, wet chamber, and intermediate chamber of the sealing plate through a pneumatic control circuit. The pressure regulating valves and pressure gauges on the air supply line can be used to adjust and display the pressure in the corresponding gas chamber in real time. Traditional pneumatic control circuits lack safety redundancy and cannot effectively cope with common problems such as loss of main air source, power failure, or slight leakage of the sealing plate air bladder. This can easily lead to the loss of sealing function due to a single fault, resulting in serious consequences such as accidental loss of primary coolant. Summary of the Invention

[0005] To address the problem that current sealing plate control devices are prone to loss of sealing function due to single faults, this invention provides a nuclear power plant evaporator sealing plate control device with redundant safety functions. It boasts high safety redundancy and can effectively eliminate the impact of common field problems such as loss of main gas supply or minor leakage of the sealing plate gas bladder. Simultaneously, the electrical control system is designed with corresponding pressure control, pressure alarm, and backup power supply functions, effectively responding to the impact of unexpected power loss in the control device and improving the operational reliability of the sealing plate.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A nuclear power plant evaporator sealing plate control device with redundant safety functions: a manual switch valve, a filter pressure reducing valve, a pressure gauge, an electrically controlled switch valve, a check valve A, a gas storage tank, a pressure sensor A, a check valve B, a solenoid reversing valve, a precision pressure reducing valve, a throttle valve, a flow meter, a pressure sensor B, and a filter are connected in sequence; the manual switch valve is connected to the gas source, and the filter is connected to the sealing plate.

[0008] Start the control device: Open the manual switch valve; adjust the filter pressure reducing valve to adjust the inlet air pressure to the allowable pressure, and check the pressure value after pressure reduction using the pressure gauge; open the electric control switch valve, at which point the air source will replenish the air tank; check the pressure in the air tank using pressure sensor A until the pressure displayed by pressure sensor A matches the pressure displayed by the pressure gauge; operate the solenoid reversing valve to the filling position, at which point the medium in the air tank will be output to the sealing plate; adjust the precision pressure reducing valve to adjust the output pressure to the allowable value, and check the pressure value after pressure reduction using pressure sensor B; adjust the throttle valve to adjust the flow rate of the output medium, and check the adjusted medium flow rate using the flow meter; the filter needs to be cleaned regularly after use.

[0009] Shutting down the control device: Disconnect the manual switch valve from the gas source; operate the solenoid directional valve to the exhaust position, at which time the medium in the sealing plate will be discharged through the solenoid directional valve; disconnect the filter from the sealing plate; operate the solenoid directional valve to the charging position, at which time the medium in the gas tank will be discharged; observe that the pressure sensor A value returns to zero; close the manual switch valve and the electric switch valve in sequence.

[0010] Manual on / off valve 0-18 bar.

[0011] Filter pressure reducing valve 40μm, 4-14bar.

[0012] The electrically controlled switch valve is a two-position three-way valve, 0-10 bar.

[0013] The gas storage tank is SS316L, 5L, 10MPa.

[0014] Precision pressure reducing valve 1-8 bar.

[0015] Throttling valve 0-8 bar.

[0016] Filter 0-20 bar, 40 μm.

[0017] The beneficial effects achieved by this invention are as follows:

[0018] This invention incorporates an air storage tank in the main gas path. If the downstream airbag leaks, the tank can promptly replenish pressure, preventing downstream malfunctions from causing sealing plate failure. A one-way valve is incorporated into the pressure control circuit to prevent main gas path loss from causing sealing plate failure. The invention uses a series control system with an electromagnetic control valve, a precision pressure reducing valve, a pressure sensor, and a flow meter to achieve pressure filling and discharging, pressure and flow regulation in user branch gas paths. This system is simple in principle and highly reliable. A UPS (Uninterruptible Power Supply) is included to provide backup power in case of power failure and to issue audible and visual alarms, preventing solenoid valve malfunction due to power loss. Filters are incorporated into the main gas path and downstream user circuits to filter impurities, preventing pneumatic component malfunctions caused by foreign objects. The invention isolates the gas paths between downstream users, ensuring that the function of a single gas path is unaffected by malfunctions in other gas paths, thus ensuring normal sealing plate function. Downstream user circuits can be added as needed; the invention has a simple structure, high reliability, and effectively guarantees the normal function of the sealing plate. Attached Figure Description

[0019] Figure 1 A schematic diagram of a nuclear power plant evaporator sealing plate control device with redundant safety functions;

[0020] In the diagram: 1-Manual on / off valve 2-Filter pressure reducing valve 3-Pressure gauge 4-Electrically controlled on / off valve 5-Check valve A 6-Gas storage tank 7-Pressure sensor 8-Check valve B 9-Solenoid directional valve 10-Precision pressure reducing valve 11-Throttle valve 12-Flow meter 13-Filter 14-Pressure sensor 15-Expandable circuit. Detailed Implementation

[0021] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0022] A nuclear power plant evaporator sealing plate control device with redundant safety functions comprises a manual switch valve 1, a filter pressure reducing valve 2, a pressure gauge 3, an electrically controlled switch valve 4, a one-way valve A5, a gas storage tank 6, a pressure sensor 7, a one-way valve B8, a solenoid reversing valve 9, a precision pressure reducing valve 10, a throttle valve 11, a flow meter 12, a pressure sensor 14, and a filter 13 connected in sequence.

[0023] This invention relates to a process design scheme for a sealing plate control device. The pneumatic control circuit comprises a main air intake circuit, an air storage tank, a gas filter, a pressure regulating valve, and a check valve. The pneumatic control circuit is connected to an external electrical control system to power electronic components such as solenoid valves, pressure sensors, and electronic flow meters. The electrical control system includes a 220V power supply, a UPS backup power supply, a solenoid valve power supply circuit, and an audible and visual alarm to enhance the redundancy and safety of the electrical control components.

[0024] The main working principle of the device is described as follows: Component 1 – before the manual switch valve is the inlet of the control circuit, connected to the air source interface; Components 1-7 form the main air path of the pneumatic control circuit, connected downstream to the user-end circuit; the main function of the main air path is to control the on / off state of the air source input and regulate the pressure of the input air source, etc.; Components 8-13 form the user-end circuit of the pneumatic control circuit, with component 8 – before the check valve being the inlet of the user-end circuit, connected to the outlet of the main air path; the main functions of the user-end circuit are to control the on / off state of the output air source, regulate the flow rate and output pressure of the output air source, discharge the pneumatic medium from the user's premises, and provide air source. The filter function of the medium; the downstream of component 13-filter is the output end of the control loop, which is connected to the sealing plate (user); during operation, the electrical control system is used to control and monitor the pressure of the main air circuit and each branch air circuit. When the pressure is lower or higher than the set pressure standard, it will issue an audible and visual alarm signal through indicator lights and buzzers to remind the operator to take appropriate measures; the UPS backup power supply in the electrical control system is used for temporary power supply when the control device loses power unexpectedly. At the same time, it can issue audible and visual alarm signals through indicator lights and buzzers to remind the operator to take appropriate measures.

[0025] Specifications of main components:

[0026] Part Number Component Name Specifications 1 Manual switch valve 0-18 bar 2 Filter pressure reducing valve 40μm 4-14bar 4 Electrically controlled switching valve Two-way three-way 0-10 bar 6 Gas storage tank SS316L 5L 10MPa 9 Solenoid directional valve Two-position five-way dual electric control 1.5-8 bar 10 Precision pressure reducing valve 1-8 bar 11 Throttling valve 0-8 bar 14 Filter 0-20 bar 40 μm 15 ups 800W

[0027] Functional description of each component: The gas storage tanks of components 1-6 are mainly used when the gas source is lost during operation. The gas stored inside can meet the needs of the sealing plate to continue working for more than 1 hour. The gas storage tank can simultaneously supply gas to multiple downstream sealing plates without interference between their respective gas supply channels. Pressure sensors 1-7 and 1-14 are installed on the main gas line and each user branch gas line of the sealing plate, respectively, to detect whether the gas supply system is under-pressure, over-pressure, or under-pressure, and issue corresponding alarm signals through the electronic control device. The one-way valve 1-5 prevents gas leakage through the solenoid valve in case of gas supply loss. The precision pressure reducing valve 1-10 and the throttle valve 1-11 can regulate the pressure and flow rate of the medium in the user-end gas line. The solenoid directional valve 1-9 allows the medium to be supplied from the main gas line to the branch gas lines, and pressurized gas in the sealing plate to be discharged through the pressure relief position. The solenoid directional valve 1-9 and the pressure sensor 1-14 work together to close the solenoid directional valve 1-9 and stop the gas supply when the medium pressure reaches the set standard value of the pressure sensor 1-14 during gas supply.

[0028] Start the control device: Connect the inlet of the pneumatic control circuit to the air source interface and the outlet to the sealing plug (user); open component 1 - manual switch valve; adjust component 2 - filter pressure reducing valve to adjust the inlet air pressure to the allowable pressure, and check the pressure value after pressure reduction through component 3 - pressure gauge; open component 4 - solenoid switch valve, at which time the air source will replenish air to component 6 - air tank; check the pressure in component 6 - air tank through component 7 - pressure gauge until the pressure displayed by component 7 - pressure gauge is consistent with the pressure displayed by component 3 - pressure gauge; operate component 9 - solenoid reversing valve to the charging position, at which time the medium in the air tank will be output to the sealing plug (user); adjust component 10 - filter pressure reducing valve to adjust the output pressure to the allowable value, and check the pressure value after pressure reduction through component 14 - pressure gauge; adjust component 11 - throttle valve to adjust the flow rate of the output medium, and check the adjusted medium flow rate value through component 12 - flow meter; after use, component 13 - filter should be cleaned regularly to avoid impurities clogging; component 15 - expandable circuit can be added repeatedly as needed.

[0029] Shut down the control device: Disconnect the pneumatic control circuit inlet from the air source interface; operate component 9 - solenoid directional valve to the exhaust position, at which time the medium in the user's body will be discharged through component 9 - solenoid directional valve; disconnect the pneumatic control circuit inlet from the sealing plate (user); operate component 9 - solenoid directional valve to the inflation position, at which time the medium in the air storage tank will be discharged through the outlet; observe component 7 - pressure gauge value returning to zero; close component 1 - manual switch valve and component 4 - solenoid switch valve in sequence.

Claims

1. A control device for a nuclear power plant evaporator sealing plate with redundant safety functions, characterized in that: The manual on / off valve, filter pressure reducing valve, pressure gauge, electrically controlled on / off valve, check valve A, air tank, pressure sensor A, check valve B, solenoid directional valve, precision pressure reducing valve, throttle valve, flow meter, pressure sensor B, and filter are connected in sequence; the manual on / off valve is connected to the air source, and the filter is connected to the sealing plug.

2. The nuclear power plant evaporator sealing plate control device with redundant safety functions according to claim 1, characterized in that: Start the control device: Open the manual switch valve; Adjust the filter pressure reducing valve to adjust the inlet air pressure to the allowable pressure, and check the pressure value after pressure reduction using a pressure gauge; Open the electronically controlled switch valve; the gas source will then replenish the gas tank. Check the pressure inside the gas tank using pressure sensor A until the pressure displayed on pressure sensor A matches the pressure gauge. Operate the solenoid directional valve to the filling position; the medium inside the gas tank will then be output to the sealing plate. Adjust the precision pressure reducing valve to adjust the output pressure to the allowable value; check the pressure value after pressure reduction using pressure sensor B. Adjust the throttle valve to regulate the flow rate of the output medium; check the adjusted flow rate using a flow meter. Clean the filter regularly after use.

3. The nuclear power plant evaporator sealing plate control device with redundant safety functions according to claim 1, characterized in that: Shutting down the control device: Disconnect the manual switch valve from the gas source; operate the solenoid directional valve to the exhaust position, at which time the medium in the sealing plate will be discharged through the solenoid directional valve; disconnect the filter from the sealing plate; operate the solenoid directional valve to the charging position, at which time the medium in the gas tank will be discharged; observe that the pressure sensor A value returns to zero; close the manual switch valve and the electric switch valve in sequence.

4. The nuclear power plant evaporator sealing plate control device with redundant safety functions according to claim 1, characterized in that: Manual on / off valve 0-18 bar.

5. The nuclear power plant evaporator sealing plate control device with redundant safety function according to claim 1, characterized in that: Filter pressure reducing valve 40μm, 4-14bar.

6. The nuclear power plant evaporator sealing plate control device with redundant safety functions according to claim 1, characterized in that: The electrically controlled switch valve is a two-position three-way valve, 0-10 bar.

7. The nuclear power plant evaporator sealing plate control device with redundant safety function according to claim 1, characterized in that: The gas storage tank is SS316L, 5L, 10MPa.

8. The nuclear power plant evaporator sealing plate control device with redundant safety functions according to claim 1, characterized in that: Precision pressure reducing valve 1-8 bar.

9. The nuclear power plant evaporator sealing plate control device with redundant safety function according to claim 1, characterized in that: Throttling valve 0-8 bar.

10. The nuclear power plant evaporator sealing plate control device with redundant safety functions according to claim 1, characterized in that: Filter 0-20 bar, 40 μm.

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