Device and method for dedusting and purifying outlet gas of primary loop of high-temperature gas cooled reactor

Abstract

The invention relates to the technical field of nuclear reactor thermotechnical hydraulic engineering, and discloses a high-temperature gas cooled reactor primary loop outlet gas dedusting and purifying device and method.The dedusting and purifying device comprises a cyclone dust collector and a high-temperature electrostatic precipitator, the cyclone dust collector is provided with a gas inlet and a gas outlet, and the inner wall face of the cyclone dust collector is provided with a protective layer; the protective layer is used for isolating high-temperature airflow from impacting an air inlet of the cyclone dust collector and is communicated with a reactor container; an air inlet and an air outlet are formed in the high-temperature electrostatic dust collector, the air inlet of the high-temperature electrostatic dust collector is communicated with the air outlet of the cyclone dust collector, and the air outlet of the high-temperature electrostatic dust collector is communicated with the steam generator; according to the invention, through the cooperation of the cyclone dust collector and the high-temperature electrostatic dust collector, graphite dust in helium can be subjected to secondary filtration treatment, so that the graphite dust in helium is effectively purified, and the inner wall of the cyclone dust collector can be prevented from being corroded by high-temperature gas through an arranged protective layer; the service life and the stability of equipment are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of nuclear reactor thermal hydraulics, in particular to a device and method for dust removal and purification of gas at a primary circuit outlet of a high-temperature gas-cooled reactor. Background Art

[0002] In the primary circuit of a high-temperature gas-cooled reactor (HTGR), gas (typically helium) is used to cool the reactor core and transfer heat to the secondary circuit for steam generation or other industrial uses. Because the gas contains tiny solid particles (such as dust and metal particles), these particles can cause wear and corrosion to equipment and systems in the circulating gas flow, and even affect the efficiency and safety of gas flow. Particularly when the gas flows through critical equipment such as the reactor and heat exchangers, the accumulation of particulate contaminants can severely degrade heat exchange performance and increase the frequency of equipment maintenance and replacement.

[0003] Therefore, how to effectively remove particulate matter in the air flow and ensure the long-term stable operation of the primary circuit of the high-temperature gas-cooled reactor has become a key issue in this technology.

[0004] Filters are used to purify particulate matter in the airflow. Although these filters can remove particulate matter in the airflow to a certain extent, due to the high temperature and high pressure environment and gas flow rate characteristics unique to high-temperature gas-cooled reactors, flue gas emissions are usually accompanied by higher temperatures, which can easily cause high-temperature corrosion to the filter devices and affect their service life. In addition, the sizes of particulate matter entrained in the airflow vary, and it is difficult for a single filter device to completely remove them. Therefore, the effectiveness and reliability of traditional dust removal methods under high temperature conditions face many challenges. It is urgent to develop new high-efficiency filtration, high-temperature resistance, and low-maintenance gas dust removal technologies to meet the operating requirements of the primary loop system of high-temperature gas-cooled reactors and ensure the long-term stability of the equipment and the safety of the system. Summary of the Invention

[0005] The purpose of the present invention is to provide a device and method for dust removal and purification of gas at the primary circuit outlet of a high-temperature gas-cooled reactor, so as to solve the problems existing in filtering and dust removal of the high-temperature helium gas flow discharged from the high-temperature gas-cooled reactor.

[0006] The technical solution of the present invention is: A high-temperature gas-cooled reactor primary circuit outlet gas dust removal and purification device comprises a cyclone dust collector, a protective layer and a high-temperature electrostatic precipitator, the cyclone dust collector is provided with an air inlet and an air outlet, the air inlet of the cyclone dust collector is used to communicate with the reactor vessel; the protective layer is arranged on the inner wall surface of the cyclone dust collector, and is used to isolate the impact of the high-temperature airflow; the high-temperature electrostatic precipitator is provided with an air inlet and an air outlet, the air inlet of the high-temperature electrostatic precipitator is communicated with the air outlet of the cyclone dust collector, and the air outlet of the high-temperature electrostatic precipitator is used to communicate with a steam generator.

[0007] Preferably, as a further improvement of the present invention, the inlet end of the cyclone dust collector is a spiral air inlet.

[0008] Preferably, as a further improvement of the present invention, an induced draft fan is provided between the high-temperature electrostatic precipitator and the steam generator, the induced draft fan having an air inlet end and an air outlet end, the air inlet end of the induced draft fan is connected to the air outlet of the high-temperature electrostatic precipitator, and the air outlet end of the induced draft fan is connected to the steam generator.

[0009] Preferably, as a further improvement of the present invention, the bottom of the cyclone dust collector is provided with an ash discharge port, the bottom of the high-temperature electrostatic dust collector is provided with multiple ash hoppers, and the ash discharge port and the outlet of each ash hopper are connected to a dust collecting tank.

[0010] Preferably, as a further improvement of the present invention, a transition funnel is connected to the dust discharge port of the cyclone dust collector, a vibration motor is provided on the outer wall of the transition funnel, and the outlet end of the transition funnel is connected to the dust collecting tank.

[0011] Preferably, as a further improvement of the present invention, there are two dust collecting tanks connected to the outlet end of the transition funnel, the two dust collecting tanks are connected to the outlet end of the transition funnel through a three-way pipeline, and a control valve is provided on the inlet pipeline of each dust collecting tank.

[0012] Preferably, as a further improvement of the present invention, the shell size parameters of the cyclone dust collector satisfy the following functional relationship: in θ is the helix angle, x is the radial dimension of the housing, y is the axial dimension of the housing, x 0 range is 4.2 m~4.6 m, y 0 range is 8.7 m~10.9 m.

[0013] Preferably, as a further improvement of the present invention, the protective layer is a ceramic lining.

[0014] Preferably, as a further improvement of the present invention, the material of the cyclone dust collector, the material of the dust collecting tank, and the material of the high-temperature electrostatic precipitator are all stainless steel.

[0015] The present invention also discloses a method for dust removal and purification of gas at the outlet of a high-temperature gas-cooled reactor primary circuit, which is implemented using the above-mentioned dust removal and purification device and includes the following steps: The high-temperature flue gas discharged from the reactor vessel is introduced into the cyclone dust collector for primary dust removal. The cyclone dust collector separates the dust particles in the flue gas through the centrifugal force of the rotating airflow. The dust particles move toward the inner wall of the cyclone dust collector due to the centrifugal force and are eventually collected in the dust collection tank. The helium gas processed by the cyclone dust collector is transported to the high-temperature electrostatic precipitator for secondary dust removal. The high-temperature electrostatic precipitator applies voltage to the airflow to generate an electric field. The dust particles that are not separated by the cyclone dust collector undergo a charge reaction under the action of the electric field and are adsorbed to the electrode surface. The helium treated by the high-temperature electrostatic precipitator is sent to the steam generator through the induced draft fan for heat exchange, completing a single-loop cycle.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. The cyclone dust collector can be used as a primary dust removal mechanism to remove larger graphite dust particles in the helium flow. The high-temperature electrostatic precipitator can be used as a secondary dust removal mechanism to further remove smaller graphite dust particles in the helium flow. The two can work together to efficiently remove graphite dust in the helium, significantly reducing the amount of dust carried in the helium before entering the steam generator, ensuring the cleanliness of the helium flow, and meeting the use requirements of the helium at the outlet of the high-temperature gas-cooled reactor.

[0017] 2. The protective layer set on the inner wall of the cyclone dust collector can achieve high-temperature protection when filtering the discharged high-temperature helium flow, avoiding corrosion and wear of the cyclone dust collector and improving the service life and stability of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the overall structure of a gas dust removal and purification device at the primary circuit outlet of a high-temperature gas-cooled reactor according to an embodiment of the present invention.

[0019] Figure 2 This is a schematic diagram of the optimized structure of a cyclone dust collector in a gas dust removal and purification device at the primary circuit outlet of a high-temperature gas-cooled reactor according to an embodiment of the present invention.

[0020] Figure 3 This is a schematic diagram of the structural dimension parameters of a cyclone dust collector in a gas dust removal and purification device at the primary circuit outlet of a high-temperature gas-cooled reactor according to an embodiment of the present invention. DETAILED DESCRIPTION

[0021] The following combination Figures 1 to 3, a detailed description of the specific embodiments of the present invention is provided. In the description of the invention, it should be understood that the terms "center," "upper," "lower," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inside," "outside," and the like, indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings and are intended only to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific direction, be constructed, or operate in a specific direction. Therefore, they should not be construed as limiting the present invention.

[0022] The terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the quantity of the technical features indicated. Therefore, features specified as "first" or "second" may explicitly or implicitly include one or more of such features; and in the description of the invention, unless otherwise specified, "plurality" means two or more.

[0023] Example 1 like Figures 1 to 2 As shown, an embodiment of the present invention provides a gas dust removal and purification device for the first-loop outlet of a high-temperature gas-cooled reactor, comprising a cyclone dust collector 2, a protective layer 8 and a high-temperature electrostatic precipitator 4. The cyclone dust collector 2 is provided with an air inlet and an air outlet, and the air inlet of the cyclone dust collector 2 is used to communicate with the reactor vessel 1; the protective layer 8 is arranged on the inner wall surface of the cyclone dust collector 2 to isolate the impact of the high-temperature airflow; the high-temperature electrostatic precipitator 4 is provided with an air inlet and an air outlet, the air inlet of the high-temperature electrostatic precipitator 4 is connected to the air outlet of the cyclone dust collector 2, and the air outlet of the high-temperature electrostatic precipitator 4 is used to communicate with the steam generator 6.

[0024] In this embodiment, the high-temperature helium discharged from the reactor vessel 1 is sent to the cyclone dust collector 2. The cyclone dust collector 2 serves as a primary dust removal mechanism to remove larger particles of graphite dust in the helium flow. The helium with fine dust particles after being treated by the cyclone dust collector 2 is input into the high-temperature electrostatic precipitator 4. The high-temperature electrostatic precipitator 4 serves as a secondary dust removal mechanism to further remove smaller particles of graphite dust in the helium flow, thereby achieving secondary treatment of the graphite dust in the helium, effectively purifying the graphite dust in the helium, significantly reducing the dust carrying amount in the helium before entering the steam generator, ensuring the cleanliness of the helium flow, and meeting the use requirements of the helium at the outlet of the high-temperature gas-cooled reactor; the protective layer 8 provided on the inner wall surface of the cyclone dust collector 2 can achieve high-temperature protection when filtering the discharged high-temperature helium flow, avoiding wear and corrosion problems of the dust removal equipment, and improving the service life and stability of the equipment.

[0025] In another embodiment of the present invention, the air inlet provided on the cyclone dust collector 2 is a spiral air inlet 7. Through the provided spiral air inlet 7, the airflow enters the cyclone dust collector more smoothly, forming a more stable rotating flow field, thereby increasing the dust removal efficiency. The high-temperature air duct and the spiral air inlet adopt a gradual form to avoid uneven distribution of the airflow.

[0026] In another embodiment of the present invention, an induced draft fan 5 is provided between the high-temperature electrostatic precipitator 4 and the steam generator 6. The induced draft fan 5 has an air inlet end and an air outlet end. The air inlet end of the induced draft fan 5 is connected to the air outlet of the high-temperature electrostatic precipitator 4, and the air outlet end of the induced draft fan 5 is connected to the steam generator 6. The treated helium is sent to the steam generator 6 for heat exchange through the provided induced draft fan 5 to complete a one-loop circulation. Through this process, the airflow can not only smoothly enter the steam generator, but also ensure the normal operation of the equipment and avoid the interference of dust on the heat exchange process.

[0027] In another embodiment of the present invention, an ash discharge port is provided at the bottom of the cyclone dust collector 2, and a plurality of ash hoppers are provided at the bottom of the high-temperature electrostatic precipitator 4. At the same time, in order to collect the separated dust particles, a dust collecting tank 3 is connected to the ash discharge port and the outlet of each ash hopper.

[0028] In another embodiment of the present invention, a transition funnel 10 is connected to the dust discharge port of the cyclone dust collector 2, and a vibration motor 9 is provided on the outer wall of the transition funnel 10. The outlet end of the transition funnel 10 is connected to the dust collecting tank 3. The vibration motor 9 is provided to apply periodic vibration to the transition funnel 10, and the dust attached to the inner wall of the transition funnel 10 is regularly discharged, so that the dust can be removed in time to prevent accumulation and reduce the dust removal efficiency.

[0029] In another embodiment of the present invention, there are two dust collecting tanks 3 connected to the outlet end of the transition funnel 10. The two dust collecting tanks 3 are connected to the outlet end of the transition funnel 10 via a three-way pipe, and a control valve is provided on the inlet pipe of each dust collecting tank 3. By adopting a dual-tank parallel design for the dust collecting tanks 3, each dust collecting tank 3 is equipped with an independent inlet control valve. During normal operation, in order to achieve continuous operation, only the inlet control valve of the dust collecting tank 3 is open, and dust particles flow into the dust collecting tank 3 with the airflow. When the dust inside the dust collecting tank 3 reaches the rated capacity, the inlet control valve of the dust collecting tank 3 will be closed and switched to the spare dust collecting tank 3. The inlet control valve of the spare dust collecting tank 3 is opened to receive a new round of dust. Through this alternating method, the continuous collection of dust is guaranteed, and the risk of equipment shutdown caused by overfilling of one dust collecting tank 3 is avoided.

[0030] In another embodiment of the present invention, in order to reduce local stress and wear caused by drastic changes in airflow, thereby extending the service life of the cyclone dust collector and improving separation efficiency, the cyclone dust collector housing is designed. The design process includes the following steps: By adjusting the spiral angle, radius growth rate, and cone length, computational fluid dynamics simulation was used to compare the flow field changes under different shell shapes and adjust the curvature and shape of the shell; Computational fluid dynamics was used to analyze the effects of different shell geometry parameters on separation efficiency, pressure loss, and flow field stability, and to obtain the optimal ranges for the helix angle, radius growth rate, and cone length. According to the obtained spiral angle, radius growth rate, and cone length, the spiral shape function suitable for the high-temperature gas-cooled reactor primary circuit outlet gas dust removal and purification device is obtained using the least squares method: in θ is the helix angle, x is the radial dimension of the housing, y is the axial dimension of the housing, x 0 range is 4.2 m~4.6 m, y 0 range is 8.7 m~10.9 m.

[0031] This function has been optimized through calculation and selects a smoother radial change to prevent sudden changes in the airflow, making the airflow more evenly distributed in the casing, reducing the local stress and wear caused by drastic changes in the airflow, and extending the service life of the cyclone dust collector. The smooth radial change can make the airflow flow inside the cyclone dust collector more stable and reduce irregular fluctuations in the airflow; this can avoid large turbulence in the airflow during rotation, reduce the local stress and wear caused by drastic changes in the airflow, thereby extending the service life of the cyclone dust collector and improving the separation efficiency.

[0032] Among them, Figure 3 As shown in the figure, the cyclone dust collector is designed based on the operating temperature of 568℃, pressure of 6.64MPa and flow rate of 114.7kg / s of the primary loop hot gas duct of the high-temperature gas-cooled reactor. The optimal range of the inner diameter of the outer cylinder is 4.2m~4.6m, the optimal range of the outer cylinder length is 6.7m~9m, the optimal range of the tapered diameter is 0.7m~1.8m, the optimal range of the cone barrel height is 8.7m~10.9m, the inner diameter of the inner cylinder is 1.4m~2.3m, the air inlet height is 1.8m~3.4m, the width is 1.1m, the total length of the funnel is 7.3m, and the dust removal rate can reach 80%.

[0033] Specifically, the protective layer is a ceramic lining, which has good corrosion resistance and high temperature resistance and can effectively resist the corrosion of high temperature gas.

[0034] In another embodiment of the present invention, the cyclone dust collector 2, the dust collecting tank 3, and the high-temperature electrostatic precipitator 4 are all made of stainless steel with a wall thickness of 250 mm, which has a shielding effect on the trace radiation carried by the high-temperature dust.

[0035] A method for dust removal and purification of gas at the outlet of a high-temperature gas-cooled reactor primary circuit is implemented using the above-mentioned dust removal and purification device, comprising the following steps: The high-temperature flue gas discharged from the reactor vessel 1 is introduced into the cyclone dust collector 2 for primary dust removal. The cyclone dust collector 2 separates most of the dust particles in the flue gas through the centrifugal force of the rotating airflow. The larger dust particles move toward the inner wall of the cyclone dust collector 2 due to the centrifugal force and are eventually collected by the dust collecting tank 3. The helium gas containing the fine dust particles after being processed by the cyclone dust collector 2 is transported to the high-temperature electrostatic precipitator 4 for secondary dust removal. The high-temperature electrostatic precipitator 4 applies a high voltage to the airflow to generate an electric field. The fine dust particles that have not been separated by the cyclone dust collector 2 undergo a charge reaction under the action of the electric field and are adsorbed onto the electrode surface. The helium treated by the high-temperature electrostatic precipitator 4 is sent to the steam generator 6 through the induced draft fan 5 for heat exchange, completing a one-loop cycle.

[0036] The above disclosures are only several preferred specific embodiments of the present invention. However, the embodiments of the present invention are not limited thereto. Any changes that can be conceived by those skilled in the art should fall within the scope of protection of the present invention.

Claims

1. A dust removal and purification device for the gas at the outlet of the primary circuit of a high-temperature gas-cooled reactor, characterized in that: include: A cyclone dust collector (2), wherein the cyclone dust collector (2) is provided with an air inlet and an air outlet, and the air inlet of the cyclone dust collector (2) is used to communicate with the reactor vessel (1); A protective layer (8) is provided on the inner wall surface of the cyclone dust collector (2) and is used to isolate the impact of the high-temperature airflow; A high-temperature electrostatic precipitator (4) is provided with an air inlet and an air outlet, the air inlet of the high-temperature electrostatic precipitator (4) is connected to the air outlet of the cyclone dust collector (2), and the air outlet of the high-temperature electrostatic precipitator (4) is used to communicate with the steam generator (6).

2. The dust removal and purification device for the primary circuit outlet gas of a high-temperature gas-cooled reactor according to claim 1 is characterized in that: The air inlet provided on the cyclone dust collector (2) is a spiral air inlet (7).

3. The dust removal and purification device for the primary circuit outlet gas of a high-temperature gas-cooled reactor according to claim 1, characterized in that: An induced draft fan (5) is provided between the high-temperature electrostatic precipitator (4) and the steam generator (6), the induced draft fan (5) having an air inlet end and an air outlet end, the air inlet end of the induced draft fan (5) being in communication with the air outlet of the high-temperature electrostatic precipitator (4), and the air outlet end of the induced draft fan (5) being in communication with the steam generator (6).

4. The dust removal and purification device for the primary circuit outlet gas of a high-temperature gas-cooled reactor according to claim 3, characterized in that: The bottom of the cyclone dust collector (2) is provided with an ash discharge port, and the bottom of the high-temperature electrostatic dust collector (4) is provided with multiple ash hoppers, and the ash discharge port and the outlet of each ash hopper are connected to a dust collecting tank (3).

5. The dust removal and purification device for the primary circuit outlet gas of a high-temperature gas-cooled reactor according to claim 3, characterized in that: A transition funnel (10) is connected to the dust discharge port of the cyclone dust collector (2), a vibration motor (9) is provided on the outer wall of the transition funnel (10), and the outlet end of the transition funnel (10) is in communication with the dust collecting tank (3).

6. The dust removal and purification device for gas at the primary circuit outlet of a high-temperature gas-cooled reactor according to claim 3, characterized in that: There are two dust collecting tanks (3) connected to the outlet end of the transition funnel (10), the two dust collecting tanks (3) are connected to the outlet end of the transition funnel (10) via a three-way pipeline, and a control valve is provided on the inlet pipeline of each dust collecting tank (3).

7. The dust removal and purification device for primary circuit outlet gas of a high-temperature gas-cooled reactor according to claim 1, characterized in that: The shell size parameters of the cyclone dust collector (2) satisfy the following functional relationship: in θ is the helix angle, x is the radial dimension of the housing, y is the axial dimension of the housing, x 0 range is 4.2 m~4.6 m, y 0 range is 8.7 m~10.9 m.

8. The dust removal and purification device for primary circuit outlet gas of a high-temperature gas-cooled reactor according to claim 1, characterized in that: The protective layer (8) is a ceramic lining.

9. The dust removal and purification device for gas at the primary circuit outlet of a high-temperature gas-cooled reactor according to claim 8, characterized in that: The material of the cyclone dust collector (2), the material of the dust collecting tank (3), and the material of the high-temperature electrostatic dust collector (4) are all made of stainless steel.

10. A method for dust removal and purification of gas at the outlet of a high-temperature gas-cooled reactor primary circuit, implemented using the dust removal and purification device according to any one of claims 4 to 9, characterized in that: The following steps are involved: The high-temperature flue gas discharged from the reactor vessel (1) is introduced into the cyclone dust collector (2) for primary dust removal. The cyclone dust collector (2) separates dust particles from the flue gas by the centrifugal force of the rotating airflow. The dust particles move toward the inner wall of the cyclone dust collector (2) due to the centrifugal force and are finally collected by the dust collecting tank (3); The helium gas processed by the cyclone dust collector (2) is transported to the high-temperature electrostatic precipitator (4) for secondary dust removal. The high-temperature electrostatic precipitator (4) applies voltage to the airflow to generate an electric field, so that the dust particles not separated by the cyclone dust collector (2) undergo charge reaction under the action of the electric field and are adsorbed onto the electrode surface. The helium treated by the high-temperature electrostatic precipitator (4) is sent to the steam generator (6) through the induced draft fan (5) for heat exchange, completing a single-loop cycle.

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