Power station air cooling island dry ice auxiliary cooling and cleaning system and method

Abstract

The invention discloses a power station air cooling island dry ice auxiliary cooling cleaning system and method, and belongs to the technical field of power station air cooling island cooling. The device is composed of a bimodal gas-solid two-phase flow nozzle, a flow field optimization nozzle support, a working medium supply unit and an intelligent control system. A dual-mode gas-solid two-phase flow nozzle is integrated on the flow field optimization nozzle support, an adjustable rotational flow generator is arranged in the nozzle, dry ice particles can be injected into the inner space of the air cooling unit, the environment temperature is reduced by means of the characteristic that dry ice sublimates to absorb heat, or the dry ice is directly injected to the outer surface of a heat dissipation pipe bundle to achieve efficient cleaning. The intelligent control system automatically switches a cooling mode and a cleaning mode and dynamically adjusts the rotational flow strength, the injection pressure and the dry ice particle size of the nozzle. The heat dissipating capacity of the air cooling island can be enhanced, and the heat dissipating tube bundle can be cleaned in a lossless mode.

Description

Technical Field

[0001] This invention belongs to the field of power plant air-cooled island cooling and maintenance technology, specifically relating to a dry ice-assisted cooling and cleaning system and method for power plant air-cooled islands. Background Technology

[0002] In the power industry, air-cooled islands are crucial cooling devices in power plants, and their cooling effect directly impacts the plant's operational efficiency and safety. During hot summer months, the ambient temperature around the air-cooled island rises, causing the temperature of the cool air blown in by the fans to increase. This significantly reduces the heat exchange efficiency of the air-cooled island, affecting the power plant's power generation efficiency and potentially leading to equipment failure due to inadequate cooling. Current common solutions include water spraying for cooling, but these methods have limited effectiveness and consume enormous amounts of water, contradicting the original purpose of air cooling.

[0003] Meanwhile, during long-term operation, the heat exchange tube bundles continuously accumulate dust, sand, oil, and other impurities from the atmosphere. These impurities adhere to the surface of the finned tubes, forming a thermal resistance layer that hinders heat exchange between the tube bundle and the airflow, further leading to a gradual decline in the heat dissipation efficiency of the air-cooled island. Currently, the cleaning methods for heat exchange finned tubes mostly involve high-pressure water washing or mechanical cleaning. High-pressure water washing may cause corrosion to the equipment and also wastes a large amount of demineralized water. Mechanical cleaning can easily damage the finned structure, and the cleaning effect is not ideal.

[0004] Therefore, there is an urgent need for a system that can effectively improve the heat dissipation performance of air-cooled islands in high-temperature weather, while also efficiently cleaning the heat dissipation tube bundles, in order to solve the problems existing in the current technology. Summary of the Invention

[0005] This invention aims to overcome the shortcomings of existing technologies and provides a dry ice-assisted cooling and cleaning system and method for air-cooled islands in power plants. This invention utilizes the heat absorption properties of dry ice sublimation and low-temperature impact to achieve integrated cooling and cleaning functions without requiring system shutdown and without damaging the heat dissipation tube bundles.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A dry ice-assisted cooling and cleaning system for an air-cooled island in a power plant includes: a dual-mode gas-solid two-phase flow nozzle, a working fluid supply unit, and an intelligent control system. The working fluid supply unit includes a compressed air tank, a pressure regulating valve, a dry ice storage and particle size separation device, a compressed air delivery pipeline, and a dry ice delivery pipeline. The outlet of the compressed air tank is connected to the compressed air inlet of the dual-mode gas-solid two-phase flow nozzle via the pressure regulating valve and the compressed air delivery pipeline. The outlet of the dry ice storage and particle size separation device is connected to the dry ice inlet of the dual-mode gas-solid two-phase flow nozzle via the dry ice delivery pipeline. The intelligent control system is communicatively connected to the pressure regulating valve, the dry ice storage and particle size separation device, and the dual-mode gas-solid two-phase flow nozzle. Based on a preset strategy or sensor feedback signals, it automatically switches between cooling and cleaning modes and dynamically adjusts the swirling intensity, injection pressure, and dry ice particle size of the nozzle.

[0007] A further improvement of the present invention is that the dual-mode gas-solid two-phase flow nozzle includes, in sequence along the medium flow direction, an ejector zone, a mixing chamber, and a diffusion section; compressed air serves as a power source, generating a high-speed jet and negative pressure in the ejector zone, automatically ejecting dry ice particles into the mixing chamber; in the mixing chamber, the dry ice particles are fully mixed with air and form a swirling flow to reduce wall impact and blockage; the mixed gas-solid two-phase flow is depressurized and accelerated through the diffusion section, resulting in a high-speed, uniform jet ejection.

[0008] A further improvement of the present invention is that an adjustable swirl generator is provided in the mixing chamber.

[0009] A further improvement of the present invention is that the adjustable swirling generator is a set of circumferentially distributed guide vanes with adjustable tilt angle; the intelligent control system drives the tilt angle of the guide vanes through a micro stepper motor, thereby changing the swirling intensity of the gas-solid two-phase flow in the mixing chamber to adapt to the diffuse flow field required for the cooling mode or the aggregated impact flow field required for the cleaning mode.

[0010] A further improvement of the present invention is that it also includes a flow field optimization nozzle support, wherein the dual-mode gas-solid two-phase flow nozzle is arranged on the flow field optimization nozzle support.

[0011] A further improvement of the present invention is that the flow field optimization nozzle support is an inverted V-shaped truss structure, installed in the space above the fan and below the heat dissipation tube bundle inside the air-cooling unit, and arranged parallel to the plane of the heat dissipation tube bundle on both sides.

[0012] A further improvement of the present invention is that the internal channel of the flow field optimization nozzle support adopts a sleeve structure, the inner tube is a dry ice channel, and the annular gap between the outer tube and the inner tube is a compressed air channel; multiple dual-mode gas-solid two-phase flow nozzles are installed on the flow field optimization nozzle support.

[0013] A further improvement of the present invention is that the dry ice storage and particle size sorting device internally stores dry ice particles of two or more different particle sizes, and integrates a particle size selection mechanism based on the principle of electromagnetic vibrating screen or airflow sorting, which can output dry ice particles of a specific particle size as needed under the instruction of the intelligent control system.

[0014] A further improvement of this invention is that the intelligent control system, based on the temperature sensor installed in the air-cooling unit and the back pressure data fed back by the unit, executes the following control logic: when the ambient temperature is higher than the set threshold, it automatically enters the auxiliary cooling mode, adjusts the compressed air pressure through the pressure regulating valve, adjusts the tilt angle of the guide vanes through the stepper motor, and controls the adjustable vortex generator to be in a weak vortex state; when the accumulated running time exceeds the set threshold, it automatically enters the online cleaning mode, adjusts the compressed air pressure through the pressure regulating valve, adjusts the tilt angle of the guide vanes through the stepper motor, and controls the adjustable vortex generator to be in a strong vortex state.

[0015] A method for dry ice-assisted cooling and cleaning of a power plant air-cooled island, the method being based on the aforementioned dry ice-assisted cooling and cleaning system for a power plant air-cooled island, comprising: The compressed air tank stores compressed air, and the pressure regulating valve adjusts the pressure of the compressed air so that the compressed air is delivered to the compressed air inlet of the dual-mode gas-solid two-phase flow nozzle through the compressed air delivery pipeline at the set pressure. The dry ice storage and particle size separation device stores dry ice and performs particle size separation on the dry ice; the separated dry ice is transported to the dry ice inlet of the dual-mode gas-solid two-phase flow nozzle through the dry ice conveying pipeline. The intelligent control system automatically switches between cooling and cleaning modes based on preset strategies or sensor feedback signals, and dynamically adjusts the swirling intensity, spray pressure, and dry ice particle size of the nozzles.

[0016] Compared with the prior art, the present invention has at least the following beneficial technical effects: This invention provides a dry ice-assisted cooling and cleaning system for power plant air-cooled islands to solve the problems of low heat dissipation efficiency of air-cooled islands and low heat exchange efficiency caused by dust accumulation on the fins of heat dissipation tubes under high temperatures. This invention uses dry ice spraying to cool the high-temperature airflow drawn into the fan, improving the heat exchange efficiency of the air-cooled island, and also to clean the heat dissipation tubes online, ensuring good heat exchange performance. This improves the operating efficiency and reliability of the power plant. Furthermore, the dry ice cleaning system uses dry ice instead of water as the cleaning and cooling material, making it effectively adaptable to arid and water-scarce regions.

[0017] Furthermore, this invention allows the compressed air injection pressure to be adjusted to 3-6 bar (lower pressure) via a pressure regulating valve, and the guide vane tilt angle to 9-10º via a stepper motor. This pressurized airflow entrains fine dry ice particles with a diameter of approximately 0.5 mm, spraying them into the vast space inside the air-cooling unit (rather than directly impacting the tube bundle). During their flight and suspension within the air-cooling unit, the dry ice particles rapidly sublimate, absorbing a large amount of heat, thereby significantly reducing the air temperature entering the heat dissipation tube bundle area, increasing the heat exchange temperature difference, and ultimately enhancing the overall cooling capacity of the air-cooling unit, effectively coping with high-temperature conditions in summer.

[0018] Furthermore, this invention allows the compressed air injection pressure to be adjusted to 10-17 bar (higher pressure) via a pressure regulating valve, and the guide vane tilt angle to 3-5º via a stepper motor. This pressurized airflow entrains larger dry ice particles with a diameter of approximately 2.8 mm, spraying them at high speed and with precision onto the outer surface of the heat dissipation tube bundle. The low-temperature dry ice (temperature -78.5℃) impacts the contaminant layer, causing the contaminants (such as oil and dust) to freeze rapidly, become brittle, and shrink, weakening their adhesion to the substrate. Simultaneously, the instantaneous sublimation of the dry ice generates a micro-explosion effect, and the shock wave peels and removes the brittle contaminants from the fin surface. The entire process requires no water or chemical agents, causes no wear or corrosion damage to the aluminum finned tubes, and can be carried out during normal unit operation.

[0019] In summary, this invention integrates both cooling and cleaning functions into a single system. Mode switching is achieved simply by adjusting the air pressure and dry ice particle size, offering high cost-effectiveness. The auxiliary cooling mode directly reduces the inlet air temperature, improving unit vacuum and thermal efficiency; the online cleaning mode keeps the heat sinks clean, maintaining the designed heat exchange efficiency, resulting in dual energy savings. Dry ice cleaning is a non-contact, abrasive-free process that does not damage the delicate heat sink fins. After cleaning, the dry ice sublimates and disappears, eliminating secondary waste. Cleaning operations do not require system shutdown, avoiding power generation loss and improving power plant availability. It does not use water or chemical cleaning agents, making it environmentally friendly. The system can automatically identify needs based on operating conditions and environmental conditions, seamlessly switching operating modes and optimizing operating parameters to achieve unmanned, precise operation and maximized energy efficiency. This invention utilizes an adjustable vortex generator to actively control the dry ice jet morphology, ensuring sufficient dispersion and sublimation of dry ice during cooling and powerful jet convergence during cleaning, significantly improving energy utilization efficiency and cleaning effectiveness. Attached Figure Description

[0020] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the overall structure of the system of the present invention applied in an air-cooled unit.

[0022] Figure 2 This is a cross-sectional view of the structural principle of the dual-mode gas-solid two-phase flow nozzle of the present invention.

[0023] Figure 3 This is a schematic diagram of the nozzle support structure of the present invention.

[0024] Figure 4 This is a schematic diagram of the adjustable swirl generator structure of the present invention.

[0025] The list of labels in the diagram is as follows: 1. Heat dissipation tube bundle, 2. Fan, 3. Dry ice storage and particle size sorting device, 4. Compressed air tank, 5. Pressure regulating valve, 6. Dual-mode gas-solid two-phase flow nozzle, 7. Flow field optimization nozzle support, 8. Compressed air delivery pipeline, 9. Dry ice delivery pipeline, 7a. Dry ice channel, 7b. Compressed air channel, 10. Guide vane. Detailed Implementation

[0026] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0027] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0028] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0029] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0030] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0031] It should be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0032] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0033] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0034] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0035] See Figure 1 In one embodiment of the present invention, it is installed in a standard air-cooling unit in the air-cooled island of a power plant. The air-cooling unit includes a heat dissipation tube bundle 1, a fan 2, and other structures.

[0036] This invention provides a dry ice-assisted cooling and cleaning system for an air-cooled island in a power plant, comprising: a dual-mode gas-solid two-phase flow nozzle 6, a flow field optimized nozzle support 7, a working fluid supply unit, and an intelligent control system. The working fluid supply unit includes a compressed air tank 4, a pressure regulating valve 5, a dry ice storage and particle size sorting device 3, a compressed air delivery pipeline 8, and a dry ice delivery pipeline 9. The intelligent control system is communicatively connected to the pressure regulating valve 5, the dry ice storage and particle size sorting device 3, and the dual-mode gas-solid two-phase flow nozzle 6. Based on a preset strategy or sensor feedback signals, it automatically switches between cooling and cleaning modes and dynamically adjusts the nozzle's swirling intensity, injection pressure, and dry ice particle size.

[0037] See Figure 2 and Figure 4 The dual-mode gas-solid two-phase flow nozzle 6 includes, sequentially along the medium flow direction, an ejection zone, a mixing chamber, and a diffusion section. Compressed air serves as the power source, generating a high-speed jet and negative pressure in the ejection zone to automatically eject dry ice particles into the mixing chamber. Inside the mixing chamber, the dry ice particles are thoroughly mixed with air, forming a swirling flow to reduce wall impact and blockage. The mixed gas-solid two-phase flow then passes through the diffusion section where pressure is reduced and speed is increased, resulting in a high-speed, uniform jet. An adjustable swirling generator is installed within the mixing chamber; this generator consists of a set of circumferentially distributed, angle-adjustable guide vanes 10. The intelligent control system drives the guide vanes to adjust their angle via a micro stepper motor, thereby changing the swirling intensity of the gas-solid two-phase flow within the mixing chamber to adapt to the diffused flow field required for cooling mode or the concentrated impact flow field required for cleaning mode.

[0038] See Figure 1 The flow field optimization nozzle support 7 is made of high-strength weather-resistant steel and has an overall inverted V-shaped truss structure. It is fixedly installed inside the air-cooled unit, above the fan 2 and below the heat dissipation tube bundle 1, and arranged parallel to the plane of the heat dissipation tube bundle 1 on both sides. (See also...) Figure 3 The internal channel of the flow field optimization nozzle support 7 adopts a sleeve structure, with the inner tube being a dry ice channel 7a and the annular gap between the outer and inner tubes being a compressed air channel 7b. Multiple dual-mode gas-solid two-phase flow nozzles 6 can be installed on the flow field optimization nozzle support 7, and the arrangement, orientation, and spacing of the nozzles can be optimized according to the actual size of the air-cooling unit and engineering requirements.

[0039] See Figure 1 The dry ice storage and particle size sorting device 3 is located on an air-cooled platform and stores dry ice particles of two or more different sizes. It supplies dry ice particles to nozzles through insulated conveying pipes. The dry ice storage and particle size sorting device 3 integrates a particle size selection mechanism based on electromagnetic vibrating screens or airflow separation principles, enabling it to output dry ice particles of specific sizes as needed under the instructions of the intelligent control system.

[0040] The intelligent control system, based on the temperature sensor installed in the air-cooling unit and the back pressure data fed back by the unit, executes the following control logic: when the ambient temperature is higher than the set threshold, it automatically enters the auxiliary cooling mode, adjusts the compressed air pressure through the pressure regulating valve 5, adjusts the tilt angle of the guide vanes through the stepper motor, and controls the adjustable vortex generator to be in a weak vortex state; when the accumulated running time exceeds the set threshold, it automatically enters the online cleaning mode, adjusts the compressed air pressure through the pressure regulating valve 5, adjusts the tilt angle of the guide vanes through the stepper motor, and controls the adjustable vortex generator to be in a strong vortex state.

[0041] Example 1: Auxiliary Cooling Mode When the ambient temperature reaches above 35℃ in summer, the efficiency of the air-cooled island decreases. Activate the auxiliary cooling mode of this system.

[0042] (1) Parameter setting: The outlet pressure of the pressure regulating valve 5 is set to 4 bar by the intelligent control system, and the tilt angle of the guide vane is adjusted to 9º by the stepper motor. The dry ice storage and particle size sorting device 3 supplies dry ice particles with a particle size of 0.5 mm.

[0043] (2) Working process: Compressed air guides fine dry ice particles into the internal space of the air-cooled unit. The dry ice particles diffuse in the air and sublimate rapidly, absorbing a large amount of heat, causing the local air temperature inside the unit to drop by 5~8℃. This low-temperature air passes through the heat dissipation tube bundle 1, significantly enhancing the heat exchange capacity of the heat dissipation tube bundle, thereby improving the vacuum degree of the unit.

[0044] (3) Effect: The unit can maintain its rated output in high temperature weather, avoiding load limitation due to excessive back pressure.

[0045] Example 2: Online Cleaning Mode After one cycle of operation, the surface of heat dissipation tube bundle 1 became heavily dusty, resulting in decreased cleanliness. The system's online cleaning mode was activated.

[0046] (1) Parameter setting: The outlet pressure of the pressure regulating valve 5 is set to 15 bar by the intelligent control system, and the tilt angle of the guide vane is adjusted to 4º by the stepper motor. The dry ice storage and particle size sorting device 3 supplies dry ice particles with a particle size of 2.8 mm.

[0047] (2) Working process: High-pressure air sprays dry ice particles at high speed onto the surface of dirt through the dual-mode gas-solid two-phase flow nozzle 6. The low-temperature freezing effect and sublimation micro-explosion effect of dry ice work together to make the dirt layer brittle and peel off rapidly, and be carried away by the airflow of the fan.

[0048] (3) Effect: The cleaning process does not require shutdown. The cleaning of one unit can be completed in 2 to 4 hours. After cleaning, the cleanliness and heat exchange efficiency of the heat exchange tube bundle 1 are restored to close to the design level, and the economic efficiency of the unit operation is significantly improved.

[0049] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the scope of the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0050] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A dry ice-assisted cooling and cleaning system for an air-cooled island in a power plant, characterized in that, include: Dual-mode gas-solid two-phase flow nozzle (6), working fluid supply unit and intelligent control system; The working fluid supply unit includes a compressed air tank (4), a pressure regulating valve (5), a dry ice storage and particle size sorting device (3), a compressed air delivery pipeline (8), and a dry ice delivery pipeline (9). The outlet of the compressed air tank (4) is connected to the compressed air inlet of the dual-mode gas-solid two-phase flow nozzle (6) through the pressure regulating valve (5) and the compressed air delivery pipeline (8). The outlet of the dry ice storage and particle size sorting device (3) is connected to the dry ice inlet of the dual-mode gas-solid two-phase flow nozzle (6) through the dry ice delivery pipeline (9). The intelligent control system communicates with the pressure regulating valve (5), the dry ice storage and particle size sorting device (3), and the dual-mode gas-solid two-phase flow nozzle (6). Based on the preset strategy or sensor feedback signal, it automatically switches between cooling and cleaning modes and dynamically coordinates the swirling intensity, spray pressure, and dry ice particle size of the nozzle.

2. The dry ice-assisted cooling and cleaning system for a power plant air-cooled island according to claim 1, characterized in that, The dual-mode gas-solid two-phase flow nozzle (6) includes an ejector zone, a mixing chamber, and a diffusion section in sequence along the medium flow direction. Compressed air serves as the power source, generating a high-speed jet and negative pressure in the ejector zone, which automatically ejects dry ice particles into the mixing chamber. In the mixing chamber, the dry ice particles are fully mixed with the air and form a swirling flow to reduce wall impact and blockage. The mixed gas-solid two-phase flow is depressurized and accelerated through the diffusion section, and a high-speed, uniform jet is ejected.

3. The dry ice-assisted cooling and cleaning system for a power plant air-cooled island according to claim 2, characterized in that, An adjustable swirl generator is installed in the mixing chamber.

4. The dry ice-assisted cooling and cleaning system for a power plant air-cooled island according to claim 3, characterized in that, The adjustable swirling generator consists of a set of circumferentially distributed guide vanes with adjustable tilt angles. The intelligent control system drives the tilt angle of the guide vanes through a micro stepper motor, thereby changing the swirling intensity of the gas-solid two-phase flow in the mixing chamber to adapt to the diffuse flow field required for cooling mode or the aggregated impact flow field required for cleaning mode.

5. The dry ice-assisted cooling and cleaning system for a power plant air-cooled island according to claim 1, characterized in that, It also includes a flow field optimization nozzle support (7), on which a dual-mode gas-solid two-phase flow nozzle (6) is arranged.

6. A dry ice-assisted cooling and cleaning system for a power plant air-cooled island according to claim 5, characterized in that, The flow field optimization nozzle support (7) has an overall inverted V-shaped truss structure. It is installed in the space above the fan (2) and below the heat dissipation tube bundle (1) inside the air-cooled unit, and is arranged parallel to the plane of the heat dissipation tube bundle (1) on both sides.

7. A dry ice-assisted cooling and cleaning system for a power plant air-cooled island according to claim 6, characterized in that, The internal channel of the flow field optimization nozzle support (7) adopts a sleeve structure, with the inner tube being a dry ice channel (7a) and the annular gap between the outer tube and the inner tube being a compressed air channel (7b); multiple dual-mode gas-solid two-phase flow nozzles (6) are installed on the flow field optimization nozzle support (7).

8. The dry ice-assisted cooling and cleaning system for a power plant air-cooled island according to claim 1, characterized in that, The dry ice storage and particle size sorting device (3) has two or more dry ice particles of different sizes stored inside, and integrates a particle size selection mechanism based on the principle of electromagnetic vibrating screen or airflow sorting. Under the instruction of the intelligent control system, it can output dry ice particles of a specific size as needed.

9. A dry ice-assisted cooling and cleaning system for a power plant air-cooled island according to claim 1, characterized in that, The intelligent control system executes the following control logic based on the temperature sensor installed in the air-cooled unit and the back pressure data fed back by the unit: when the ambient temperature is higher than the set threshold, it automatically enters the auxiliary cooling mode, adjusts the compressed air pressure through the pressure regulating valve (5), adjusts the guide vane tilt angle through the stepper motor, and controls the adjustable vortex generator to be in a weak vortex state; when the running time accumulates to exceed the set threshold, it automatically enters the online cleaning mode, adjusts the compressed air pressure through the pressure regulating valve (5), adjusts the guide vane tilt angle through the stepper motor, and controls the adjustable vortex generator to be in a strong vortex state.

10. A method for dry ice-assisted cooling and cleaning of an air-cooled island in a power plant, characterized in that, This method is based on a dry ice-assisted cooling and cleaning system for a power plant air-cooled island according to any one of claims 1 to 9, comprising: The compressed air tank (4) stores compressed air, and the pressure regulating valve (5) regulates the pressure of the compressed air so that the compressed air is delivered to the compressed air inlet of the dual-mode gas-solid two-phase flow nozzle (6) through the compressed air delivery pipeline (8) at the set pressure. The dry ice storage and particle size sorting device (3) stores dry ice and sorts the dry ice by particle size; the sorted dry ice is transported to the dry ice inlet of the dual-mode gas-solid two-phase flow nozzle (6) through the dry ice conveying pipe (9); The intelligent control system automatically switches between cooling and cleaning modes based on preset strategies or sensor feedback signals, and dynamically adjusts the swirling intensity, spray pressure, and dry ice particle size of the nozzles.

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