Anti-freezing device for direct air cooling unit

Abstract

The utility model provides an anti-freezing device for a direct air cooling unit. The anti-freezing device comprises a pipeline fan, a ventilation pipeline, a first blocking side plate and a second blocking side plate. The first plugging side plate and the second plugging side plate are respectively arranged outside the corresponding radiating fin tube bundles, so that a heat collection space is formed between the plugging side plate and the corresponding radiating fin tube bundles; the ventilation pipeline is arranged below the two heat dissipation fin tube bundles, the ventilation pipeline and the two heat dissipation fin tube bundles form a triangular heat dissipation space of the air cooling island unit through the ventilation pipeline, a first air inlet of the ventilation pipeline is connected to the first heat collection space, and a second air inlet of the ventilation pipeline is connected to the second heat collection space; an air outlet of the ventilation pipeline extends into the triangular heat dissipation space of the air cooling island unit, and the pipeline fan is arranged at the preset position, close to the air outlet, of the ventilation pipeline. According to the air cooling island unit, the triangular heat dissipation space of the air cooling island unit is heated through mechanical plugging and recovery of heat dissipated by the air cooling island, and the anti-freezing effect is achieved.

Description

Technical Field

[0001] This application relates to the field of direct air-cooled antifreeze technology, and in particular to an antifreeze device for direct air-cooled units. Background Technology

[0002] In Northwest China, direct air cooling has become a common method for cooling exhaust steam in thermal power units. Exhaust steam from the turbine is fed into an air-cooled island cooling system, where it is cooled by convective heat transfer driven by air-cooled fans. However, in winter, the operation of directly air-cooled units is susceptible to freezing and cracking of the finned tube bundles on the air-cooled island due to ambient temperature fluctuations, severely impacting the safety and stability of the unit's operation. Especially in snowy weather, snowflakes absorbing heat and evaporating on the finned tube bundles carry away a significant amount of heat, leading to freezing. Under deep peak-shaving and low-load conditions, the turbine exhaust volume decreases, further increasing the subcooling and freezing risk of condensate in this section of the pipeline. At such times, ambient temperatures may reach around -20 degrees Celsius, causing large-scale freezing of the air-cooled finned tube bundles, affecting the safe and economical operation of the unit.

[0003] Currently, to prevent equipment freezing, a series of antifreeze technologies have been adopted, such as air-cooled island steam injection antifreeze, heating antifreeze protection, and emergency water drainage. However, existing heating antifreeze and steam injection antifreeze do not take into account energy consumption costs, require higher heat source temperatures, resulting in large resource consumption, low heating efficiency, and low antifreeze benefits. This does not conform to the low-carbon and energy-saving development concept of power plants, and increases antifreeze costs. Utility Model Content

[0004] In view of this, the purpose of this application is to provide an antifreeze device for direct air-cooled units to overcome at least one of the above-mentioned defects.

[0005] In a first aspect, embodiments of this application provide an anti-freezing device for a direct air-cooled unit. The anti-freezing device includes a waste heat recovery system. Each air-cooled unit is equipped with a waste heat recovery system, and each waste heat recovery system includes a duct fan, a ventilation duct, a first sealing side plate, and a second sealing side plate. The direct air-cooled unit includes multiple air-cooled units, and each air-cooled unit includes an exhaust duct, a first heat dissipation finned tube bundle, and a second heat dissipation finned tube bundle. One end of the exhaust duct is connected to the exhaust outlet of the generator turbine to receive steam, and the other end of the exhaust duct is connected to one end of each heat dissipation finned tube bundle to transmit steam to each heat dissipation finned tube bundle. The first sealing side plate is disposed on the first heat dissipation finned tube bundle. Externally, a first heat-collecting space is formed between the first sealing side plate and the first heat dissipation fin bundle. A second sealing side plate is disposed outside the second heat dissipation fin bundle, forming a second heat-collecting space between the second sealing side plate and the second heat dissipation fin bundle. The ventilation duct is arranged below the two heat dissipation fin bundles to form a triangular heat dissipation space for the air-cooled island unit. The first air inlet of the ventilation duct is connected to the first heat-collecting space, the second air inlet of the ventilation duct is connected to the second heat-collecting space, and the air outlet of the ventilation duct extends into the triangular heat dissipation space of the air-cooled island unit. The duct fan is disposed at a preset position near the air outlet of the ventilation duct.

[0006] In one optional embodiment of this application, the antifreeze device further includes a first control butterfly valve and a second control butterfly valve, wherein the first control butterfly valve is disposed at a first position in the ventilation duct near the first air inlet; and the second control butterfly valve is disposed at a second position in the ventilation duct near the second air inlet.

[0007] In one optional embodiment of this application, the air outlet includes a T-shaped air outlet, wherein the first air outlet of the T-shaped air outlet is disposed opposite to the first heat dissipation fin bundle, the second air outlet of the T-shaped air outlet is disposed opposite to the second heat dissipation fin bundle, and the height of the T-shaped air outlet extending into the triangular heat dissipation space of the air-cooled island unit corresponds to a preset height at the bottom of each heat dissipation fin bundle.

[0008] In one optional embodiment of this application, the antifreeze device further includes a first bracket, a first baffle, a second bracket, and a second baffle. The first baffle is fixed to the outside of the first heat dissipation fin bundle below the first bracket, and the first air inlet of the ventilation duct is disposed between the first sealing side plate and the first baffle. The second baffle is fixed to the outside of the second heat dissipation fin bundle below the second bracket, and the second air inlet of the ventilation duct is disposed between the second sealing side plate and the second baffle.

[0009] In one optional embodiment of this application, the antifreeze device further includes a mechanical sealing system. A mechanical sealing system is provided outside each heat dissipation fin bundle of each air-cooled unit. Each mechanical sealing system includes a drive shaft, a motor, a crossbeam connecting rod, an insulation board, a drive steel wire rope, a C-shaped track, and guide wheels. The C-shaped track is located on the outside of the sealing side plate. Multiple crossbeam connecting rods are arranged at preset intervals along the length of the C-shaped track. The insulation board is composed of multiple sub-insulation boards spliced ​​together. Each sub-insulation board is positioned between each crossbeam connecting rod. Each sub-insulation board completes one inward fold. Both ends of each crossbeam connecting rod are connected to the drive steel wire rope. The two ends of the drive steel wire rope are respectively connected to the guide wheel and the drive shaft. The drive shaft is connected to the motor. The motor drives the drive shaft to rotate, thereby opening the sub-insulation board through the drive steel wire rope and the crossbeam connecting rod, covering the outer surface of the corresponding sealing side plate.

[0010] In one optional embodiment of this application, the antifreeze device further includes a first windbreak guide rail, a second windbreak guide rail, a first windbreak curtain, and a second windbreak curtain. The first windbreak guide rail and the second windbreak guide rail are spliced ​​together to form a total windbreak guide rail. The length of the total windbreak guide rail matches the length below the triangular heat dissipation space of the air-cooled island unit. The first windbreak curtain is arranged on the first windbreak guide rail to move along the guide rail direction to block cold air from entering the triangular heat dissipation space of the air-cooled island unit.

[0011] In one optional embodiment of this application, the air-cooled unit further includes two condensate pipes and an air-cooled island fan. Each condensate pipe is connected to the other end of each heat dissipation fin bundle to transport the condensate generated during the heat dissipation process of the corresponding heat dissipation fin bundle to the turbine cooling system. The air-cooled island fan is installed below the triangular heat dissipation space of the air-cooled island unit to drive cold air to convect and exchange heat with each heat dissipation fin bundle in the triangular heat dissipation space of the air-cooled island unit, cooling and condensing the turbine exhaust steam in the heat dissipation fin bundle into water, which then flows into the corresponding condensate pipe.

[0012] In one optional embodiment of this application, the antifreeze device further includes a temperature sensor, wherein the temperature sensor includes two upper temperature sensors and two lower temperature sensors. Each upper temperature sensor is disposed at a preset position on the upper part of the inner side of the corresponding heat dissipation fin tube bundle, and each lower temperature sensor is disposed at a preset position on the lower part of the inner side of the corresponding heat dissipation fin tube bundle. When the steam flow direction is in a co-current arrangement, a lower temperature sensor is provided; when the steam flow direction is in a counter-current arrangement, both upper and lower temperature sensors are provided.

[0013] In one optional embodiment of this application, the antifreeze device further includes a controller. The controller receives temperature values ​​detected by a temperature sensor and generates a first start signal when the temperature value is lower than a first alarm threshold and higher than a second alarm threshold. The first start signal is sent to a first and a second windproof curtain to control each windproof curtain to move along a corresponding windproof guide rail and, when it moves to a preset position, to block cold air from entering the triangular heat dissipation space of the air-cooled island unit. When the temperature value is lower than the second alarm threshold and higher than a third alarm threshold, a second start signal is generated and sent to the motor to drive the drive shaft to rotate, causing the sub-insulation plate to open and cover the outer surface of the corresponding sealing side plate. When the temperature value is lower than the third alarm threshold, a third start signal is generated and sent to the duct fan to control the hot air absorbed from each heat collection space to be sprayed through the air outlet of the ventilation duct into the triangular heat dissipation space of the air-cooled island unit for antifreeze purposes. When the temperature value is lower than the third alarm threshold, the controller issues a low-temperature warning. When the temperature value is lower than a fourth alarm threshold, the controller issues an ultra-low temperature alarm.

[0014] This application provides an anti-freezing device for direct air-cooled units. This device effectively divides and manages the heat collection space within the air-cooled unit through the design of a duct fan, ventilation ducts, a first sealing side plate, and a second sealing side plate. Specifically, the device utilizes the sealing side plates to form a heat collection space outside the heat dissipation fin bundle, connects these spaces through ventilation ducts, and is equipped with a duct fan to promote airflow. This application achieves an anti-freezing effect, ensuring the stable operation of the direct air-cooled unit.

[0015] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 One of the schematic diagrams of an antifreeze device for a direct air-cooled unit provided in the embodiments of this application;

[0018] Figure 2 This is a second schematic diagram of an antifreeze device for a direct air-cooled unit provided in an embodiment of this application.

[0019] Reference numerals in the attached drawings: 1. Exhaust pipe; 2. Side sealing plate; 3. Heat dissipation fin bundle; 4. Condensate pipe; 5. Lower temperature sensor; 6. Upper temperature sensor; 7. First control butterfly valve; 8. Second control butterfly valve; 9. Air outlet; 10. Duct fan; 11. Ventilation duct; 12. Windproof curtain; 13. Air-cooled island fan; 14. Drive shaft; 15. Motor; 16. Crossbeam connecting rod; 17. Sub-insulation board; 18. Drive wire rope; 19. C-shaped track; 20. Guide wheel; 21. Bracket; 22. Baffle plate. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0021] In the description of the embodiments of this application, it should be noted that the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model product is in use. They are only for the convenience of describing the utility model 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 the utility model. In addition, the terms "first," "second," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0022] In the description of the embodiments of this application, it should also be noted that, unless otherwise explicitly specified and limited, the terms "provided with," "installed," "connected," and "connected" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0023] First, the applicable application scenarios of this application will be introduced. This application can be applied to the field of direct air-cooling antifreeze technology.

[0024] Research has found that in snowy weather, snowflakes fall on the finned tube bundles, absorb heat and evaporate, taking away a large amount of heat and causing the finned tube bundles to freeze. Under the deep peak shaving and low load conditions of the unit, the turbine exhaust volume is reduced, which further increases the subcooling of condensate in this part of the pipeline and the risk of freezing. At this time, the ambient temperature may reach about minus 20 degrees Celsius, which will cause the air-cooled finned tube bundles to freeze in patches, affecting the safe and economical operation of the unit.

[0025] Furthermore, existing heating-based antifreeze and steam-assisted antifreeze methods require higher heat source temperatures, have lower heating efficiency, and do not provide significant antifreeze benefits, which does not align with the power plant's low-carbon and energy-saving development philosophy.

[0026] To address at least one of the aforementioned problems, this application provides an antifreeze device for a direct air-cooled unit. The antifreeze device includes a duct fan, a ventilation duct, a first sealing side plate, and a second sealing side plate. The direct air-cooled unit includes multiple air-cooled units. Each air-cooled unit includes an exhaust duct, a first heat dissipation finned tube bundle, and a second heat dissipation finned tube bundle. One end of the exhaust duct is connected to the exhaust outlet of the generator turbine to receive steam, and the other end of the exhaust duct is connected to one end of each heat dissipation finned tube bundle to transmit steam to each heat dissipation finned tube bundle. The first sealing side plate is disposed outside the first heat dissipation finned tube bundle to prevent frost damage to the first heat dissipation finned tube bundle. A first heat-collecting space is formed between the sealing side plate and the first heat dissipation fin bundle. A second sealing side plate is disposed outside the second heat dissipation fin bundle, forming a second heat-collecting space between the second sealing side plate and the second heat dissipation fin bundle. A ventilation duct is arranged below the two heat dissipation fin bundles to form a triangular heat dissipation space for the air-cooled island unit. The first air inlet of the ventilation duct is connected to the first heat-collecting space, the second air inlet of the ventilation duct is connected to the second heat-collecting space, and the air outlet of the ventilation duct extends into the triangular heat dissipation space of the air-cooled island unit. A duct fan is disposed at a predetermined position near the air outlet of the ventilation duct. This application prevents steam condensation at low temperatures, achieving an antifreeze effect.

[0027] This application effectively blocks the space below the triangular heat dissipation space of the air-cooled island unit, reducing the impact of cold air on the heat dissipation system and preventing icing. The overall design of the antifreeze device aims to improve the stability and reliability of the generator set and reduce the risk of downtime caused by icing of the heat dissipation system.

[0028] Specifically, the air-cooled unit also includes two condensate pipes and an air-cooled island fan 13;

[0029] Each condensate pipe is connected to the other end of each heat dissipation fin bundle to transfer the condensate generated during the heat dissipation process of the corresponding heat dissipation fin bundle to the turbine's cooling system.

[0030] The air-cooled island fan 13 is installed below the triangular heat dissipation space of the air-cooled island unit to drive the cold air to convect and exchange heat with each heat dissipation fin bundle 3 in the triangular heat dissipation space of the air-cooled island unit, cooling and condensing the turbine exhaust steam in the heat dissipation fin bundle 3 into water, which is then collected into the corresponding condensate pipe 4.

[0031] Please see Figure 1 , Figure 1 This is one of the schematic diagrams of an anti-freezing device for a direct air-cooled unit provided in an embodiment of this application. For example... Figure 1 As shown, the antifreeze device provided in this application embodiment includes an exhaust pipe 1, a sealing side plate 2, a heat dissipation fin bundle 3, a condensate pipe 4, a lower temperature sensor 5, an upper temperature sensor 6, a first control butterfly valve 7, a second control butterfly valve 8, an air outlet 9, a duct fan 10, a ventilation duct 11, a main windproof curtain 12, an air-cooled island fan 13, a first bracket 21, and a first baffle plate 22.

[0032] The direct air-cooled unit includes multiple air-cooled units. Each air-cooled unit includes an exhaust pipe 1, a first heat dissipation fin tube bundle, and a second heat dissipation fin tube bundle. One end of the exhaust pipe 1 is connected to the exhaust outlet of the generator turbine to receive steam, and the other end of the exhaust pipe is connected to one end of each heat dissipation fin tube bundle 3 to transmit steam to each heat dissipation fin tube bundle 3.

[0033] Specifically, the antifreeze device includes a waste heat utilization system. Each air-cooled unit is equipped with a waste heat utilization system. Each waste heat utilization system includes a duct fan 10, a ventilation duct 11, a first sealing side plate, and a second sealing side plate. The first sealing side plate is located outside the first heat dissipation fin tube bundle to form a first heat collection space between the first sealing side plate and the first heat dissipation fin tube bundle. The second sealing side plate is located outside the second heat dissipation fin tube bundle to form a second heat collection space between the second sealing side plate and the second heat dissipation fin tube bundle.

[0034] Here, the exhaust pipe 1 serves as the main channel for steam transmission, connecting one end to the exhaust outlet of the generator turbine and the other end to the heat dissipation finned tube bundle 3, ensuring that steam can flow smoothly into the heat dissipation system. The heat dissipation finned tube bundle 3 is used to receive and dissipate heat from the steam. The finned structure increases the heat dissipation area and improves heat dissipation efficiency.

[0035] For example, the exhaust steam from the steam turbine of a thermal power generating unit is discharged through a pipeline to the exhaust steam pipe 1 of an outdoor air-cooled island. The exhaust steam pipe 1 of the air-cooled island has multiple rows, and each exhaust steam pipe 1 of the air-cooled island is equipped with a steam inlet valve. Each exhaust steam pipe 1 of the air-cooled island has two inclined heat dissipation fin bundles 3 forming a triangular cooling unit. Each row of air-cooled island heat dissipation fin bundles 3 includes a co-current row and a counter-current row. The steam turbine exhaust first enters the co-current row for cooling and then enters the counter-current row for cooling. Therefore, in cold weather, under the deep peak shaving and low load conditions of the unit, the low temperature region of the direct air-cooled unit is the lower end of the co-current row and the counter-current row.

[0036] This application enables the unit to effectively maintain the air-cooled island at a suitable temperature during deep peak shaving and low load conditions in winter, preventing tube bundle icing or even freezing and cracking, and ensuring the normal operation of the cooling system.

[0037] Specifically, the antifreeze device also includes a first windbreak guide rail, a second windbreak guide rail, a first windbreak curtain, and a second windbreak curtain. The first windbreak guide rail and the second windbreak guide rail are spliced ​​together to form a total windbreak guide rail. The length of the total windbreak guide rail matches the length below the triangular heat dissipation space of the air-cooled island unit. The first windbreak curtain is arranged on the first windbreak guide rail to move along the guide rail direction to block cold air from entering the triangular heat dissipation space of the air-cooled island unit from below.

[0038] Preferably, when the first and second windproof curtains are in the unfolded state, the width of the total windproof curtain 12 corresponds to the width below the triangular heat dissipation space of the air-cooled island unit, and the length of the total windproof curtain 12 is half the length of the total windproof guide rail.

[0039] Here, the antifreeze device is equipped with first and second wind-blocking guide rails and wind-blocking curtains, which effectively block cold air from entering from below the air-cooled island and reduce heat loss. At the same time, it forms a triangular sealed space with the two heat dissipation fin bundles in the air-cooled island unit.

[0040] The ventilation duct 11 is arranged below the two heat dissipation fin bundles 3 to form a triangular heat dissipation space of the air-cooled island unit through the ventilation duct 11 and the two heat dissipation fin bundles. The first air inlet of the ventilation duct 11 is connected to the first heat collection space, the second air inlet of the ventilation duct 11 is connected to the second heat collection space, and the air outlet 9 of the ventilation duct 11 extends into the triangular heat dissipation space of the air-cooled island unit. The duct fan 10 is set at a preset position near the air outlet 9 of the ventilation duct 11.

[0041] In a preferred embodiment, the duct fan can be a variable frequency fan to adjust the ventilation volume of the ventilation duct. Based on the temperature monitoring system, temperature data and condensate temperature are collected. By adjusting the power of the duct fan 10, the amount of hot air entering the triangular heat dissipation space of the air-cooled island unit is increased through the ventilation duct 11, ensuring that the heat dissipation fin bundle 3 will not freeze and crack. This application can achieve air-cooled island antifreeze under the deep peak-shaving and low-load conditions of the unit in winter.

[0042] Depending on whether the air outlet is in the forward or reverse flow configuration, it can be located in the lower or upper half of the triangular heat dissipation space of the air-cooled island unit.

[0043] The antifreeze device of this application is suitable for generator sets in cold climates, especially those that need to operate continuously for a long time. The device can ensure that the generator set can maintain efficient and stable operation even under extreme weather conditions.

[0044] Specifically, the waste heat utilization system also includes a first control butterfly valve 7 and a second control butterfly valve 8. The first control butterfly valve 7 is located at a first position in the ventilation duct 11 near the first air inlet; the second control butterfly valve 8 is located at a second position in the ventilation duct 11 near the second air inlet.

[0045] Here, by adjusting the opening of the first control butterfly valve 7 and the second control butterfly valve 8, the airflow entering the two heat collection spaces can be precisely controlled. In low-temperature environments, by adjusting the amount of hot air entering the heat dissipation space, the risk of finned tube bundle freezing can be reduced. This adjustment capability is crucial for preventing freezing.

[0046] Specifically, the waste heat utilization system also includes an air outlet 9, which is a T-shaped air outlet. The first air outlet of the T-shaped air outlet is arranged opposite to the first heat dissipation fin tube bundle, and the second air outlet of the T-shaped air outlet is arranged opposite to the second heat dissipation fin tube bundle. The height of the T-shaped air outlet extending into the triangular heat dissipation space of the air-cooled island unit corresponds to the preset height of the bottom of each heat dissipation fin tube bundle.

[0047] The T-shaped air outlet design allows for more even air distribution across the two heat dissipation fin bundles, thus improving heat dissipation efficiency. Precise control of the outlet's position and height ensures that the airflow fully contacts the heat dissipation fin bundles, effectively carrying away heat.

[0048] In low-temperature environments, the T-shaped air outlet design helps reduce the accumulation of cold air around the heat sink finned tube bundle, thereby reducing the risk of the finned tube bundle freezing. By adjusting the position and height of the air outlet, the airflow path can be further optimized, reducing the direct impact of cold air on the heat sink finned tube bundle.

[0049] The T-shaped air outlet design helps maintain the temperature balance of the triangular heat dissipation space in the air-cooled island unit. By precisely controlling the airflow and distribution, the occurrence of localized overcooling can be reduced, thereby improving the stability of the entire system and enabling the air-cooled island to prevent freezing during periods of severe winter cold or deep peak shaving under low load conditions.

[0050] The waste heat utilization system also includes a first support, a first baffle, a second support, and a second baffle. Taking the first baffle 22 and the first support 21 as examples, the first baffle 22 is fixed to the outside of the first heat dissipation fin tube bundle below the first support 21. The first air inlet of the ventilation duct 11 is located between the first sealing side plate and the first baffle 22. The second baffle is fixed to the outside of the second heat dissipation fin tube bundle below the second support. The second air inlet of the ventilation duct 11 is located between the second sealing side plate and the second baffle. The first baffle 22 is used to enhance the collection of hot air in the first heat collection space by the ventilation duct 11. Here, the size of the first baffle 22 can be adjusted according to the size of the air-cooled island.

[0051] The first and second baffles are fixed to the outside of the first and second heat dissipation fin bundles, respectively, effectively guiding the airflow in the ventilation duct. The design of the baffles ensures that air can enter the heat collection space more evenly, avoiding the formation of local eddies or dead zones, thereby improving the heat dissipation efficiency of the heat dissipation fin bundles.

[0052] By precisely setting the position and angle of the baffle, the contact area and time between the air and the heat dissipation fin bundle can be further optimized, thereby enhancing the heat dissipation effect. This helps to utilize waste heat more effectively, improve the energy efficiency of the entire system, help maintain the temperature balance of the heat collection space, prevent steam condensation and freezing, and ensure the normal operation of the system. The design of the first and second brackets allows the baffle to be easily fixed to the outside of the heat dissipation fin bundle. This design not only simplifies the installation process but also facilitates subsequent maintenance and repair work.

[0053] Please see Figure 2 , Figure 2 This is a second schematic diagram of an antifreeze device for a direct air-cooled unit provided in an embodiment of this application. (See diagram below.) Figure 2 As shown, the antifreeze device provided in this application embodiment also includes a drive shaft 14, a motor 15, a crossbeam connecting rod 16, a sub-insulation plate 17, a drive steel wire rope 18, a C-shaped track 19, and a guide wheel 20.

[0054] Here, the antifreeze device also includes a mechanical sealing system. A mechanical sealing system is installed on the outside of each heat dissipation fin bundle of each air-cooled unit. Each mechanical sealing system includes a drive shaft 14, a motor 15, a crossbeam connecting rod 16, a sub-insulation plate 17, a drive steel wire rope 18, a C-shaped track 19, and a guide wheel 20.

[0055] C-shaped track 19 is set on the outside of the sealing side plate 2. Multiple crossbeam connecting rods 16 are set at preset intervals along the length of C-shaped track 19. The insulation board is spliced ​​together from multiple sub-insulation boards 17. Each sub-insulation board 17 is set between each crossbeam connecting rod 16. Each sub-insulation board completes one inward fold. Both ends of each crossbeam connecting rod 16 are connected to the transmission steel wire rope 18. Both ends of the transmission steel wire rope 18 are connected to the guide wheel 20 and the transmission shaft 14, respectively. The transmission shaft 14 is connected to the motor 15. The motor 15 drives the transmission shaft 14 to rotate so as to open the sub-insulation board 17 through the transmission steel wire rope 18 and the crossbeam connecting rod 16 and cover the outer surface of the corresponding sealing side plate 2.

[0056] Here, the mechanical sealing side plate 2 is installed on the outside of each heat dissipation fin tube bundle 3, serving as the main structure of the sealing system, and is used to seal the top of the heat dissipation fin tube bundle when needed.

[0057] The C-shaped track 19 is located on the outside of the sealing side plate 2 to guide the movement of the crossbeam connecting rod 16 and the insulation plate 17. The design of the C-shaped track allows the crossbeam connecting rod 16 and the sub-insulation plate 17 to move smoothly within the track.

[0058] The crossbeam connecting rod 16 is connected between the C-shaped rails 19 to support and connect the sub-insulation panels 17, ensuring that the sub-insulation panels can be opened or closed stably.

[0059] The transmission wire rope 18 is connected between multiple crossbeam connecting rods 16 and is connected to the motor 15 through the guide wheel 20 and the transmission shaft 14. When the motor 15 is running, the transmission wire rope 18 will drive the crossbeam connecting rods 16 and the sub-insulation plate 17 to move.

[0060] The guide wheel 20 is used to guide the movement of the transmission wire rope 18, ensuring that the wire rope remains smooth and stable during transmission.

[0061] The drive shaft 14 is connected to the motor 15 and is used to transmit the power of the motor to drive the movement of the transmission wire rope 18.

[0062] This application uses a drive shaft to open the insulation plate, thereby sealing the outer surface of the heat dissipation finned tube bundle. The insulation plate is designed to effectively form a heat collection space, preventing the finned tube bundle from freezing due to snowflakes directly falling on it and absorbing heat and evaporating. Each component of the mechanical sealing system is carefully designed to ensure stable operation even under extreme weather conditions. The structure is clear, and the connections between components are simple and straightforward, facilitating daily maintenance and repair.

[0063] Figure 1In the process, the antifreeze device also includes temperature sensors, which include two upper temperature sensors and two lower temperature sensors. Each upper temperature sensor 6 is set at a preset position on the upper part of the corresponding heat dissipation fin tube bundle, and each lower temperature sensor 5 is set at a preset position on the lower part of the corresponding heat dissipation fin tube bundle. The upper temperature sensors 6 and lower temperature sensors 5 can monitor the temperature of the heat dissipation fin tube bundle 3 of the air-cooled island in real time.

[0064] Each upper temperature sensor 6 is configured to activate when the steam flow direction is detected to be counter-current, and each lower temperature sensor 5 is configured to activate when the steam flow direction is detected to be co-current.

[0065] Furthermore, based on the different gas flow directions within the heat dissipation fins of the air-cooled island, the air-cooled island unit is divided into co-current and counter-current columns. According to the characteristics of the co-current and counter-current columns, the co-current column takes the temperature value collected by the lower temperature sensor, while the counter-current column takes the temperature values ​​collected by the upper and lower temperature sensors.

[0066] Here, in the forward flow configuration, steam flows from the exhaust pipe 1 along the heat dissipation finned tube bundle to the condensate pipe 4, and the temperature value collected by the lower temperature sensor 5 is used as the basis for monitoring and alarm.

[0067] The upper end of the counter-flow heat dissipation fin tube bundle is connected to a vacuum system. In the counter-flow column, the uncondensed steam in the condensate pipe 4 flows upward from the heat dissipation fin tube bundle, and the flow direction is opposite to that of the co-flow column. At this time, the counter-flow column takes the temperature values ​​collected by the lower temperature sensor 5 and the upper temperature sensor 6 as the basis for monitoring and alarm.

[0068] Specifically, the antifreeze device also includes a controller, which receives the temperature value detected by the temperature sensor and generates a first start signal when the temperature value is lower than the first alarm threshold and higher than the second alarm threshold. The controller sends the first start signal to the first windproof curtain and the second windproof curtain to control each windproof curtain to move along the corresponding windproof guide rail and block cold air from entering the triangular heat dissipation space of the air-cooled island unit when it moves to the preset position.

[0069] When the temperature value is lower than the second alarm threshold and higher than the third alarm threshold, a second start signal is generated and sent to the motor to drive the drive shaft to rotate so that the sub-insulation plate opens to cover the outer surface of the corresponding sealing side plate.

[0070] When the temperature value is lower than the third alarm threshold, a third start signal is generated and sent to the duct fan to control the hot air absorbed from each heat collection space to be sprayed through the air outlet of the ventilation duct to the triangular heat dissipation space of the air-cooled island unit for antifreeze. When the temperature value is lower than the third alarm threshold, the controller issues a low temperature warning to the operators; when the temperature value is lower than the fourth alarm threshold, the controller issues an ultra-low temperature alarm to the operators.

[0071] Based on the operation of the air-cooled island and the unit back pressure data, the temperature values ​​collected by the temperature sensor are set with two alarm thresholds: the first alarm threshold T1, the second alarm threshold T2, the third alarm threshold T3, and the fourth alarm threshold T4, where T1>T2>T3>T4.

[0072] Here, the arrangement of the upper temperature sensor 6 and the lower temperature sensor 5 ensures accurate monitoring of temperature changes in the heat sink finned tube bundle 3 under different steam flow directions. This helps to detect and respond to potential temperature situations in a timely manner.

[0073] By monitoring data from temperature sensors, the equipment is ensured to operate under safe and efficient conditions. If the temperature sensor detects an abnormal temperature, it triggers a corresponding antifreeze operation to prevent steam condensation at low temperatures, thus achieving a direct antifreeze effect.

[0074] In the first embodiment, when the unit faces a period of deep winter cold or a low-load condition during peak shaving, the amount of steam discharged from the turbine in the exhaust pipe 1 is relatively small. The temperature value collected by the temperature sensor is sent to the controller. The controller monitors whether the temperature value reaches the anti-freeze alarm threshold. When the collected temperature value reaches or is less than the first alarm threshold T1 and is higher than the second alarm threshold T2, the windproof curtain 12 is activated to block the bottom of the triangular heat dissipation space of the air-cooled island unit, preventing cold air from entering the triangular heat dissipation space of the air-cooled island unit, thereby reducing the convective heat transfer of the air-cooled island heat dissipation fin bundle 3.

[0075] Temperature sensors monitor the surface temperature of the heat sink fin bundle in real time. Once the temperature drops below the first alarm threshold and above the second alarm threshold, the antifreeze mechanism is triggered. The windproof curtain effectively blocks the space below the triangular heat dissipation space of the air-cooled island unit, reducing the impact of cold air on the heat dissipation system and preventing icing.

[0076] In the second embodiment, when the collected temperature value reaches or is less than the second alarm threshold T2 and is higher than the third alarm threshold T3, the motor 15 is started to provide driving force, which drives the transmission shaft 14 to rotate and drive the transmission wire rope 18 to open the sub-insulation plate 17 to cover the outer surface of the corresponding sealing side plate 2, thereby mechanically sealing the outer surface of the heat dissipation fin tube bundle 3 of the air-cooled island unit.

[0077] In the third embodiment, when the collected temperature value reaches or is less than the third alarm threshold T3, the duct fan 10 is started to control the hot air absorbed from each heat collection space to be sprayed through the air outlet 9 of the ventilation duct 11 to the triangular heat dissipation space of the air-cooled island unit for antifreeze. When the temperature value is lower than the third alarm threshold T3, the controller issues a low temperature warning to the operators. The overall design of the antifreeze device aims to improve the stability and reliability of the generator set and reduce the risk of shutdown caused by the cooling system freezing.

[0078] In the fourth embodiment, when the collected temperature value is less than the fourth alarm threshold T4, the controller issues an ultra-low temperature alarm to the operators.

[0079] For example, the alarm thresholds and the corresponding warning procedures for each temperature change can be limited according to the actual situation.

[0080] In summary, by activating different temperature sensors based on the gas flow direction and collecting corresponding temperature values, precise monitoring of the temperature inside the heat dissipation fins of the air-cooled island is achieved. Three alarm thresholds are set, which can issue timely warnings and emergency alarms based on temperature changes, improving the safety and reliability of the system. By monitoring the data from the temperature sensors, the operating parameters of the air-cooled island can be adjusted in real time to ensure that the equipment operates under safe and efficient conditions.

[0081] In a preferred embodiment, this application includes an air-cooled island system, a mechanical sealing system, and a waste heat utilization system. The mechanical sealing system covers the outer surface of the triangular heat dissipation space of the air-cooled island unit, and a windproof curtain is set below the triangular heat dissipation space of the air-cooled island unit to reduce the entry of cold air into the triangular heat dissipation space of the air-cooled island unit, achieving physical sealing and antifreeze. The waste heat utilization system can spray the hot air in the space formed by the sealing side plate and the heat dissipation fin bundle through pipes to the triangular heat dissipation space and the low-temperature tube bundle area of ​​the air-cooled island unit. This application does not require heat outside the air-cooled island system of the thermal power unit, but utilizes the waste heat of the turbine exhaust in the air-cooled island, which improves energy utilization efficiency, has high flexibility, is relatively simple to implement, and has good antifreeze effect. It can realize antifreeze of the air-cooled island of the air-cooled unit under deep peak shaving and low load conditions, and can effectively improve the economy and safety stability of the unit in winter operation.

[0082] For example, firstly, a windproof curtain is installed below the triangular heat dissipation space of the air-cooled island unit to prevent cold air from entering the triangular heat dissipation space of the air-cooled island unit, thereby reducing the convective heat transfer of the air-cooled island heat dissipation fin bundle. Furthermore, an insulation plate is used to cover the outer surface of the heat dissipation fin bundle on both sides through a mechanical sealing system, and a heat collection space is formed between the sealing side plate and the heat dissipation fin bundle. Cold air recovers the waste heat of the turbine exhaust steam through heat exchange in the heat dissipation fins, forming hot air that is concentrated in the heat collection space. This hot air is then transported and sprayed to the low-temperature area of ​​the triangular heat dissipation space of the air-cooled island unit through ventilation ducts, thereby increasing the air temperature in the triangular heat dissipation space of the air-cooled island unit and achieving the antifreeze effect of the air-cooled island tube bundle.

[0083] This application enables the mechanical sealing system to operate independently, or it enables the use of a waste heat recovery system to heat the air-cooled island finned tube bundle after mechanical sealing. This can improve the problem of condensate freezing in low ambient temperatures and low load conditions during deep peak shaving in winter, prevent condensate pipes from freezing and the air-cooled island heat dissipation finned tube bundles from freezing and cracking, reduce heat loss, and effectively improve the economic efficiency and safety stability of the unit during winter operation.

[0084] This application incorporates a mechanical sealing system on the exterior of the heat dissipation finned tube bundle, preventing rapid heat loss caused by rain and snow falling onto the bundle during winter. Combined with the windproof curtain beneath the triangular heat dissipation space of the air-cooled island unit, complete sealing of the unit is achieved. Furthermore, this application eliminates the need for additional heat from the thermal power unit's air-cooled island system; instead, it improves energy efficiency by recovering and utilizing waste heat from steam exhaust.

[0085] This application can effectively maintain a suitable temperature for the air-cooled island under deep peak-shaving and low-load conditions, prevent tube bundle icing, and ensure the normal operation of the cooling system.

[0086] This application provides an anti-freezing device for a direct air-cooled unit. The anti-freezing device includes a waste heat recovery system. Each air-cooled unit is equipped with a waste heat recovery system, and each waste heat recovery system includes a duct fan, a ventilation duct, a first sealing side plate, and a second sealing side plate. The direct air-cooled unit includes multiple air-cooled units. Each air-cooled unit includes an exhaust duct, a first heat dissipation finned tube bundle, and a second heat dissipation finned tube bundle. One end of the exhaust duct is connected to the exhaust outlet of the generator turbine to receive steam, and the other end of the exhaust duct is connected to one end of each heat dissipation finned tube bundle to transfer steam to each heat dissipation finned tube bundle. The first sealing side plate is disposed on the first heat dissipation finned tube. The first heat-collecting space is formed between the first sealing side plate and the first heat dissipation fin tube bundle outside the second heat dissipation fin tube bundle. A second sealing side plate is disposed outside the second heat dissipation fin tube bundle, forming a second heat-collecting space between the second sealing side plate and the second heat dissipation fin tube bundle. A ventilation duct is arranged below the two heat dissipation fin tube bundles to form a triangular heat dissipation space for the air-cooled island unit. The first air inlet of the ventilation duct connects to the first heat-collecting space, the second air inlet connects to the second heat-collecting space, and the air outlet extends into the triangular heat dissipation space of the air-cooled island unit. A duct fan is positioned at a predetermined location near the air outlet of the ventilation duct. This application prevents steam condensation and freezing at low temperatures, achieving a direct antifreeze effect.

[0087] Finally, it should be noted that the above-described embodiments are merely specific implementations of this application, used to illustrate the technical solutions of this application, and not to limit them. The protection scope of this application is not limited thereto. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features, within the technical scope disclosed in this application. Such modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be covered within the protection scope of this application. Therefore, the protection scope of this application should be determined by the protection scope of the claims.

Claims

1. An anti-freezing device for a direct air-cooling unit, characterized by, The anti-freezing device comprises a waste heat utilization system, each air cooling unit is provided with a waste heat utilization system, each waste heat utilization system comprises a pipeline fan, a ventilation pipeline, a first blocking side plate and a second blocking side plate, The direct air cooling unit comprises a plurality of air cooling units, each air cooling unit comprises a steam exhaust pipeline, a first heat dissipation finned tube bundle and a second heat dissipation finned tube bundle, one end of the steam exhaust pipeline is connected with a steam exhaust outlet of a turbine of a generator set to receive steam, and the other end of the steam exhaust pipeline is connected with one end of each heat dissipation finned tube bundle to transmit the steam into each heat dissipation finned tube bundle; The first blocking side plate is arranged outside the first heat dissipation finned tube bundle to form a first heat collection space between the first blocking side plate and the first heat dissipation finned tube bundle, and the second blocking side plate is arranged outside the second heat dissipation finned tube bundle to form a second heat collection space between the second blocking side plate and the second heat dissipation finned tube bundle; The ventilation pipeline is arranged below the two heat dissipation finned tube bundles to form an air cooling island unit triangular heat dissipation space through the ventilation pipeline and the two heat dissipation finned tube bundles, a first air inlet of the ventilation pipeline is connected to the first heat collection space, a second air inlet of the ventilation pipeline is connected to the second heat collection space, an air outlet of the ventilation pipeline extends into the air cooling island unit triangular heat dissipation space, and the pipeline fan is arranged at a preset position of the ventilation pipeline close to the air outlet.

2. The freeze protection apparatus of claim 1, wherein The anti-freezing device further comprises a first control butterfly valve and a second control butterfly valve, The first control butterfly valve is arranged at a first position of the ventilation pipeline close to the first air inlet; The second control butterfly valve is arranged at a second position of the ventilation pipeline close to the second air inlet.

3. The anti-freezing device according to claim 1 or 2, characterized in that The air outlet comprises a T-shaped air outlet, The first air inlet of the T-shaped air outlet is arranged opposite to the first heat dissipation finned tube bundle, the second air inlet of the T-shaped air outlet is arranged opposite to the second heat dissipation finned tube bundle, and the height of the T-shaped air outlet extending into the air cooling island unit triangular heat dissipation space corresponds to a preset height of the bottom of each heat dissipation finned tube bundle.

4. The freeze protection apparatus of claim 3, wherein, The anti-freezing device further comprises a first support, a first baffle, a second support and a second baffle, The first baffle is fixed outside below the first heat dissipation finned tube bundle through the first support, and the first air inlet of the ventilation pipeline is arranged between the first blocking side plate and the first baffle; The second baffle is fixed outside below the second heat dissipation finned tube bundle through the second support, and the second air inlet of the ventilation pipeline is arranged between the second blocking side plate and the second baffle.

5. The freeze protection apparatus of claim 1, wherein The anti-freezing device further comprises a mechanical blocking system, each mechanical blocking system is arranged outside each heat dissipation finned tube bundle of each air cooling unit, and each mechanical blocking system comprises a transmission shaft, a motor, a cross beam connecting rod, a sub-heat preservation plate, a transmission steel wire rope, a C-shaped track and a guide wheel, The C-shaped track is arranged outside the blocking side plate, a plurality of beam connecting rods are arranged on the C-shaped track at preset intervals along the length direction of the C-shaped track, the insulation board is spliced by a plurality of sub-insulation boards, each sub-insulation board is arranged between each beam connecting rod, each sub-insulation board is folded inward once, the two ends of each beam connecting rod are connected with the transmission steel wire rope, the two ends of the transmission steel wire rope are respectively connected with a guide wheel and a transmission shaft, the transmission shaft is connected with a motor, the motor drives the transmission shaft to rotate to open the sub-insulation board through the transmission steel wire rope and the beam connecting rod, and the sub-insulation board covers the outer surface of the corresponding blocking side plate.

6. The freeze protection apparatus of claim 1, wherein The anti-freezing device further comprises a first wind-blocking guide rail, a second wind-blocking guide rail, a first wind-blocking curtain and a second wind-blocking curtain, The first wind-blocking guide rail and the second wind-blocking guide rail are spliced into a total wind-blocking guide rail, the length of the total wind-blocking guide rail matches the length below the triangular heat dissipation space of the air-cooling island unit, and the first wind-blocking curtain is arranged on the first wind-blocking guide rail to move along the guide rail to block cold air from entering the triangular heat dissipation space of the air-cooling island unit.

7. The freeze protection apparatus of claim 1, wherein The air-cooling machine unit further comprises two condensate water pipes and an air-cooling island fan, Each condensate water pipe is connected with the other end of each heat dissipation finned tube bundle to transmit the condensate water generated in the heat dissipation process of the corresponding heat dissipation finned tube bundle to the cooling system of the steam turbine; The air-cooling island fan is installed below the triangular heat dissipation space of the air-cooling island unit to drive the cold air to convectively exchange heat with each heat dissipation finned tube bundle in the triangular heat dissipation space of the air-cooling island unit, cool the steam turbine exhaust steam in the heat dissipation finned tube bundle to condense into water, and flow into the corresponding condensate water pipe.

8. The freeze protection apparatus of claim 5, wherein, The anti-freezing device further comprises a temperature sensor, The temperature sensor comprises two upper temperature sensors and two lower temperature sensors, each upper temperature sensor is arranged at a preset position on the upper side of the corresponding heat dissipation finned tube bundle, and each lower temperature sensor is arranged at a preset position on the lower side of the corresponding heat dissipation finned tube bundle; when the flow direction of the steam is downstream, the lower temperature sensor is arranged; when the flow direction of the steam is upstream, the upper temperature sensor and the lower temperature sensor are arranged at the same time.

9. The anti-icing device of claim 6 or 8, wherein, The anti-freezing device further comprises a controller, The controller is used to receive the temperature value detected by the temperature sensor, generate a first start signal when the temperature value is lower than a first alarm threshold value and higher than a second alarm threshold value, and send the first start signal to the first wind-blocking curtain and the second wind-blocking curtain to control each wind-blocking curtain to move along the corresponding wind-blocking guide rail and block the cold air from entering the triangular heat dissipation space of the air-cooling island unit when the wind-blocking curtain moves to a preset position; When the temperature value is lower than the second alarm threshold value and higher than a third alarm threshold value, a second start signal is generated, and the second start signal is sent to the motor to drive the transmission shaft to rotate to open the sub-insulation board to cover the outer surface of the corresponding blocking side plate. When the temperature value is lower than the third alarm critical value, a third start signal is generated and sent to the duct fan to control the hot air absorbed from each heat collection space to be sprayed to the triangular heat dissipation space of the air cooling island unit through the air outlet of the ventilation duct to prevent freezing; and when the temperature value is lower than the third alarm critical value, the controller issues a low temperature early warning; and when the temperature value is lower than the fourth alarm critical value, the controller issues an ultralow temperature alarm.

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