A device for enhancing the emergency response capacity of the containment spray system by means of charge injection

Abstract

The present invention relates to a device for enhancing the emergency response capability of a containment spray system using charge injection, belonging to the field of heat and mass transfer technology. The device comprises a negative-pressure high-voltage power supply and a positive-pressure high-voltage power supply disposed outside the containment, an insulated spray system, and a needle-mesh electrode disposed within the containment. A high-voltage needle-tip electrode is disposed within the spray manifold outside the containment. The negative electrode of the negative-pressure high-voltage power supply is connected to the needle-tip electrode, with the positive electrode grounded. The positive electrode of the positive-pressure high-voltage power supply is connected to the needle-mesh electrode, with the negative electrode grounded. The tip of the needle-mesh electrode points vertically upward toward the spray system's nozzle. The present invention utilizes discharge from the needle-mesh electrode to generate positively charged droplets and radioactive aerosols. The Coulomb force between these droplets and the negatively charged spray droplets disrupts the non-condensable gas layer near the spray droplets. Furthermore, the spray droplets oscillate and oscillate under the electric field, thereby reducing heat transfer resistance and increasing the adsorption rate of radioactive aerosols, thereby enhancing heat and mass transfer.

Description

Technical Field

[0001] The present invention relates to the technical field of heat and mass transfer, and in particular to a device for improving the emergency response capability of a containment spray system by utilizing charge injection. Background Art

[0002] The nuclear power plant containment spray system is one of the specialized safety features of pressurized water reactor (PWR) nuclear power plants. In the event of a serious accident, the spray system condenses steam within the containment and absorbs radioactive aerosols, thereby reducing the temperature and pressure within the containment and removing radioactive aerosols, ensuring the safety and integrity of the containment.

[0003] On the one hand, the spray system's cooling and pressure reduction primarily depends on the steam heat transfer efficiency, but the thermal resistance of the spray droplets and the thermal resistance of the non-condensable gas layer both reduce heat transfer efficiency. On the other hand, the spray system's removal rate of radioactive aerosols depends on the probability of collision between the spray droplets and the aerosols. Therefore, the current focus of enhancing the emergency response capabilities of the containment spray system is to reduce the diameter of the spray droplets, increase the spray flow rate, and increase the spray coverage area by increasing pressure or modifying complex nozzles. This requires a higher-performance spray system power pump and more complex spray pipes and nozzles. While this strengthening technology also has a high strengthening effect, its production process is complex, requires higher equipment performance, and consumes a lot of energy. Summary of the Invention

[0004] One of the purposes of the present invention is to provide a device that uses charge injection to enhance the emergency response capability of the containment spray system, which can enhance the containment spray system's ability to cool and depressurize the containment under severe accident conditions and increase the adsorption of radioactive aerosols, thereby quickly and effectively removing radioactive products such as airborne particles or elemental iodine.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A device for improving the emergency response capability of a containment spray system by using charge injection, comprising a negative-pressure high-voltage power supply and a positive-pressure high-voltage power supply arranged outside the containment, an insulation-treated spray system, and a needle-mesh electrode arranged inside the containment. A high-voltage needle-tip electrode is provided in a spray header outside the containment, wherein the negative-pressure high-voltage power supply has a negative electrode connected to the high-voltage needle-tip electrode and a positive electrode grounded, and the positive electrode of the positive-pressure high-voltage power supply has a positive electrode connected to the needle-mesh electrode and a negative electrode grounded, and the tip of the needle-mesh electrode points vertically upward toward the nozzle of the spray system.

[0007] Furthermore, the spray header, nozzles and other remaining parts of the spray system of the present invention are all treated with insulating materials.

[0008] Furthermore, the needle-mesh electrode tips of the present invention are arranged on several layers of concentric metal rings.

[0009] Furthermore, the metal rings of the present invention are connected in series, and each metal ring and the series connection lines between them are covered with insulating materials.

[0010] Furthermore, the tip of the needle-mesh electrode of the present invention is made of a needle-tip-shaped metal material, and the curvature radius of the tip is ≤50 μm.

[0011] Furthermore, the high-voltage needle tip electrode of the present invention is a gold-plated stainless steel needle.

[0012] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0013] First, the present invention utilizes high-voltage needle-tip electrode discharge in the spray manifold to make the spray droplets negatively charged. The spray droplets oscillate and deform under the electric field, causing disturbances inside the droplets, thereby reducing the thermal resistance of the spray droplets.

[0014] Second, the present invention utilizes a positive-pressure high-voltage power supply to form a strong electric field near the needle tip of the needle-mesh electrode to ionize the nearby air and generate positive ions. On the one hand, the positive ions can act as condensation nuclei to adsorb steam to form positively charged droplets. On the other hand, the positive ions will also adhere to the radioactive aerosol and cause it to carry a positive charge. Under the action of Coulomb force, the positively charged radioactive aerosol and droplets and the negatively charged spray droplets disturb the non-condensable gas layer outside the spray droplets, reduce the thermal resistance of the non-condensable gas layer and enhance the migration process of steam and radioactive aerosol to the spray droplets, thereby enhancing the heat transfer efficiency and increasing the probability of aerosol adhesion.

[0015] Third, although the present invention uses a high-voltage power supply, the energy consumption is extremely low due to the extremely small discharge current, and each part is fully insulated and protected, effectively increasing the safety and feasibility of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the present invention.

[0017] Figure 2 It is a schematic diagram of the arrangement of high-voltage needle-tip electrodes in the spray header of the present invention.

[0018] Figure 3 It is a microscopic principle diagram of the oscillation of spray droplets under the electric field of the present invention.

[0019] Figure 4 It is a microscopic principle diagram of the heat and mass transfer process of the present invention.

[0020] Figure numerals: 1-negative high-voltage power supply, 2-positive high-voltage power supply, 3-insulated spray system, 4-needle-mesh electrode, 5-spray collection pipe, 6-high-voltage needle tip electrode, 7-nozzle, 8-needle-mesh electrode tip, 9-metal concentric rings, 10-wire, 11-positive ions, 12-spray droplets, 13-non-condensable gas layer, 14-radioactive aerosol, 15-droplets. DETAILED DESCRIPTION

[0021] The present invention provides a device for enhancing the emergency response capability of a containment spray system by utilizing charge injection. To make the objectives, technical solutions, and effects of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments. The accompanying drawings are for illustrative purposes only and represent only schematic diagrams, not actual images, and should not be construed as limiting this patent. To better illustrate the embodiments of the present invention, certain components and device connections in the drawings are omitted, enlarged, or reduced in size, and do not represent the dimensions of the actual product. It is understandable to those skilled in the art that certain well-known structures and their descriptions may be omitted from the drawings.

[0022] like Figure 1-Figure 2 Figure 1 shows a device that uses charge injection to enhance the emergency response capability of a containment spray system. The device's main structure includes a negative-pressure high-voltage power supply 1 and a positive-pressure high-voltage power supply 2, located outside the containment; an insulated spray system 3; and a needle-mesh electrode 4 located within the containment. A high-voltage needle-tip electrode 6 is located within a manifold outside the containment. The negative electrode 1 of the negative-pressure high-voltage power supply is connected to the needle-tip electrode 6 via a wire 10, with the positive electrode grounded. The positive electrode of the positive-pressure high-voltage power supply 2 is connected to the needle-mesh electrode 4 via a wire 10, with the negative electrode grounded. The needle-mesh electrode tip 8 is a gold-plated stainless steel needle pointing vertically upward toward the spray system's nozzle 7. The spray manifold 5, nozzle 7, and other remaining components of the spray system 3 are treated with insulating material. In this embodiment, the needle-mesh electrode tips are arranged on several layers of concentric metal rings, which are connected in series. Each metal ring and the connecting circuit are coated with insulating material.

[0023] Figure 3 and Figure 4This is a microscopic principle diagram of the present invention. The specific process is described as follows: when the spray system is started, the high-voltage needle tip electrode 6 can discharge the spray liquid, so that the spray droplets 12 are negatively charged. The spray droplets oscillate and deform under the electric field, and disturbances occur inside the droplets, thereby reducing the thermal resistance of the spray droplets 12. The tip of the needle-mesh electrode 4 is made of a needle-tip-shaped metal material, and its tip curvature radius is ≤50μm. The curvature radius of the needle-mesh electrode tip 8 is very small. When the applied voltage is large, the strong electric field formed near the needle-mesh electrode tip 8 ionizes the surrounding air and generates positive ions 11. On the one hand, the positive ions 11 can act as condensation nuclei to adsorb steam to form positively charged droplets 15. On the other hand, the positive ions will also adhere to the radioactive aerosol 14 and cause it to be positively charged. Under the action of Coulomb force, the positively charged radioactive aerosol 14 and droplets 15 and the negatively charged spray droplets 12 disturb the non-condensable gas layer 13 outside the spray droplets 12, reducing the thermal resistance of the non-condensable gas layer 13 and enhancing the migration process of steam and radioactive aerosol to the spray droplets, thereby enhancing the heat transfer efficiency and increasing the probability of aerosol adhesion.

[0024] The device of this embodiment uses a high-voltage needle-tip electrode 6 to discharge the spray liquid, negatively charging spray droplets 12. Under the electric field, the spray droplets 12 oscillate and deform, creating internal disturbances within the droplets, thereby reducing the thermal resistance of the spray droplets 12. Simultaneously, the strong electric field formed near the needle-mesh electrode tip 8 ionizes the surrounding air and generates positive ions 11. These positive ions 11 act as condensation nuclei, adsorbing vapor to form positively charged droplets 15. Furthermore, these positive ions also attach to radioactive aerosols 14, imparting a positive charge to them. The positively charged radioactive aerosols 14 and droplets 15, combined with the negatively charged spray droplets 12, act under Coulomb force to disrupt the non-condensable gas layer 13 outside the spray droplets 12, reducing the thermal resistance of the non-condensable gas layer 13 and enhancing the migration of vapor and radioactive aerosols into the spray droplets, thereby enhancing heat transfer and increasing the probability of aerosol adhesion. Furthermore, despite the device's high operating voltage, its minimal discharge current results in extremely low energy consumption, and all components are fully insulated and protected, effectively ensuring the device's safety and feasibility. In summary, the present invention enhances the spray system's heat transfer efficiency and increases the probability of radioactive aerosol adsorption during accident conditions. Furthermore, the device boasts a simple structure, easy operation, and active control capabilities, effectively improving the containment spray system's emergency response capabilities and ensuring the safety and stability of the containment.

[0025] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A device for improving the emergency response capability of the containment spray system by using charge injection, characterized in that , including a negative pressure high voltage power supply (1) and a positive pressure high voltage power supply (2) arranged outside the containment, a spray system (3) after insulation treatment, and a needle mesh electrode (4) arranged inside the containment. The spray system (3) after the insulation treatment includes a spray header (5) and a nozzle (7); a high-voltage needle tip electrode (6) is provided in the spray header (5) outside the containment, the negative electrode of the negative high-voltage power supply is connected to the high-voltage needle tip electrode, the positive electrode is grounded, the positive electrode of the positive high-voltage power supply is connected to the needle mesh electrode, the negative electrode is grounded, and the tip of the needle mesh electrode is vertically upward pointing to the nozzle (7) of the spray system; The needle mesh electrode (4) comprises a needle mesh electrode tip (8) and a metal ring (9), wherein the needle mesh electrode tip (8) is arranged on a plurality of layers of concentric metal rings (9); the metal rings (9) are connected in series, and each metal ring (9) and the series connection lines therebetween are covered with an insulating material; The needle mesh electrode tip (8) is vertically pointed upward toward the nozzle (7) of the spray system, so that the negatively charged spray droplets (12) oscillate and deform under the electric field to reduce thermal resistance. At the same time, the positively charged droplets (15) and radioactive aerosols (14) disturb the non-condensable gas layer (13) outside the spray droplets through Coulomb force and enhance aerosol adsorption.

2. The device for improving the emergency response capability of the containment spray system by using charge injection according to claim 1, characterized in that: The spray header (5), the spray head (7) and other remaining parts of the spray system are all treated with insulating materials.

3. The device for improving the emergency response capability of the containment spray system by using charge injection according to claim 1, characterized in that: The needle mesh electrode needle tip (8) is made of a needle tip-shaped metal material, and the tip curvature radius is ≤50 μm.

4. The device for improving the emergency response capability of the containment spray system by using charge injection according to claim 1, characterized in that: The high-voltage needle tip electrode (6) is a gold-plated stainless steel needle.

Images