Performance-controllable air-cooled condenser antifreeze device and its multiple antifreeze working modes

Abstract

The present invention relates to an air-cooled condenser and its antifreeze operating mode for use in thermal power generation, biomass power generation, petrochemical industry, and steam turbine power equipment. The purpose is to provide a performance-controllable air-cooled condenser antifreeze device and its multiple antifreeze operating modes. The device and antifreeze operating modes should be applicable to extremely cold regions and have the characteristics of automatic or manual control, multiple optional control modes, precise temperature control, and low cost of use. The technical solution is: a performance-controllable air-cooled condenser antifreeze device, characterized in that: the device also includes a plurality of fourth electric shutters installed on the walls around the wind chamber, a plurality of third electric shutters installed on the lower part of the wind chamber, and a plurality of second electric shutters installed below the walkway; the fourth electric shutters, the third electric shutters, and the second electric shutters are all electrically connected to the air cooler DCS system.

Description

Technical Field

[0001] The present invention relates to an air-cooled condenser and its antifreeze working mode used in thermal power generation, biomass power generation, petrochemical industry, and steam turbine power equipment, and in particular to a blast-type direct air-cooled condenser device, including blast-type direct air-cooled condenser devices with various tube bundle layouts such as single-row tubes and multiple-row tubes, and corresponding antifreeze working modes. Background Art

[0002] In recent years, with the rapid growth of my country's economy, the installed capacity of steam turbines in large-scale oil refining and waste incineration power generation projects has increased rapidly, leading to a corresponding increase in demand for air-cooled condensers (ACs). Due to market competition, an increasing number of AC condenser manufacturers are opting for designs that utilize large-diameter fans and long tube bundles, which offer relatively lower overall costs. However, in extremely cold regions, where winter temperatures often drop below -20°C, condensate within the AC condenser tube bundles can freeze. In severe cases, the expanding ice can directly burst through the finned tubes, causing damage and leakage in the AC condenser. Increased backpressure can cause turbine shutdowns, resulting in significant losses. (The cost of an AC condenser for an industrial steam turbine typically ranges from 300W to 3000W, while the cost of an AC condenser for a power generation steam turbine typically ranges from 5000W to 300 million yuan.)

[0003] To address the frozen pipe problem, the industry has adopted various measures. CN207066169U discloses an antifreeze air cooler that installs a steam-heated pipe bank below the process air cooler's tube bundle to heat the bundle's inlet air during antifreeze operations. However, the heated pipe bank at the bottom of the bundle is also finned, significantly impacting the static air pressure and significantly reducing the air cooler's heat exchange performance. Furthermore, the heated pipe bank has a limited effect on raising the air cooler's temperature, failing to ensure uniform heating of the upper tube bundle. Furthermore, the upper finned tubes of frozen pipes further reduce the heating effect. This requires the introduction of high-temperature steam for antifreeze operations, which is costly and prevents precise temperature control. CN210773569U discloses a hot air circulation air cooler that installs a wind box above the process air cooler's tube bundle and an airflow guide with a heating pipe below the bundle. Two fans are installed below each tube bundle, with a wind box below each fan. A partition divides the process air cooler into two sections, one on the left and one on the right. During operation, the two fans blow air in opposite directions, while the heating pipes are activated simultaneously to increase the internal temperature, creating a hot air circulation system. The drawbacks are that the upper, middle, and lower bellows and heating tube bundles significantly increase the static pressure of the air cooler, significantly reducing its heat exchange performance. Furthermore, the upper and lower bellows must be closed during operation, making it impossible to control the temperature. The heating tube bundles increase winter operating costs. CN210773569U discloses a hot air circulation air cooler that combines two process air coolers into a single unit to achieve a hot air circulation similar to that described in CN210773569U, with mutual circulation between the two units via a bellows. Its drawback is that it is only applicable to horizontally arranged process air coolers and has only one hot air circulation operating mode. The high static pressure of each bellows significantly impacts heat exchange capacity. Summary of the Invention

[0004] The purpose of the present invention is to overcome the shortcomings of the above-mentioned background technology and provide an air-cooled condenser antifreeze device with controllable performance and its multiple antifreeze working modes. The device and the antifreeze working mode should be able to be used in extremely cold areas, and have the characteristics of automatic or manual control, multiple control modes to choose from, precise temperature control and low cost of use.

[0005] The technical solution provided by the present invention is:

[0006] A performance-controllable air-cooled condenser antifreeze device comprises an air chamber fixed by a lower support structure, a fan platform mounted on top of the air chamber and supported by the lower support structure, a walkway arranged around the fan platform, a fan mounted on the air-cooled condenser fan platform and a fan drive mechanism, and an air-cooled condenser DCS system electrically connecting the fan drive mechanism and various sensors. The device is characterized by:

[0007] The device also includes a plurality of fourth electric shutters installed on the walls around the wind chamber, a plurality of third electric shutters installed at the bottom of the wind chamber, and a plurality of second electric shutters installed below the aisle; the fourth electric shutters, the third electric shutters, and the second electric shutters are all electrically connected to the air cooler DCS system.

[0008] The wind chamber is provided with a plurality of air temperature transmitters electrically connected to the DCS system.

[0009] The device also includes a first electric shutter covering the upper half of the heat exchange tube bundle on the leeward side of the air-cooled condenser and electrically connected to the DCS system of the air-cooler; by adjusting the opening and closing and intermediate states of the first electric shutter, the cooling air volume of the upper half of the heat exchange tube bundle is controlled.

[0010] The walkway is formed by connecting two gable side walkways and two slope side walkways; the gable side walkways are paved with patterned steel plates to ensure sealing, while the slope side walkways are paved with grille plates to ensure ventilation; the second electric blinds are laid correspondingly under the grille plates of the slope side walkways.

[0011] The working mode of the above-mentioned performance-controllable air-cooled condenser antifreeze device is as follows:

[0012] The first method: When the ambient temperature is below 0°C and the DCS system of the air cooler indicates that the degree of subcooling is greater than 3°C, the third electric shutter at the bottom of the air chamber is closed, and the fourth electric shutter on the walls around the air chamber are adjusted in the same proportion; the opening of the fourth electric shutter is controlled to a minimum of 10%; the second electric shutter is kept closed and the first electric shutter is kept 100% open;

[0013] The second method: After the first working mode is put into use, when the DCS system of the air cooler again shows that the subcooling degree is greater than 3°C, close the third electric shutter at the bottom of the air chamber and maintain the minimum opening of the fourth electric shutter at 10%, while keeping the second electric shutter closed; control the opening of the first electric shutter 3 to the minimum of closed;

[0014] The third mode: After the second working mode is put into use, when the DCS system of the air cooler again shows that the subcooling degree is greater than 3°C, close the first electric shutter; close the third electric shutter and maintain the minimum opening of the fourth electric shutter at 10%; open and control the opening of the second electric shutter to a minimum of 20%;

[0015] As the outside temperature gradually drops and the subcooling data in the air cooler DCS system is used to judge, the air cooler antifreeze device can sequentially adopt one of the three working modes mentioned above.

[0016] In addition, when there are multiple fan units in the same row of the air-cooled condenser and one of the units is overcooled individually (commonly, the countercurrent tube bundle unit is overcooled individually), the third electric shutter of the unit is closed and the fourth electric shutter is kept at a minimum opening of 10%, and the first electric shutter of the unit is kept closed, the second electric shutter of the unit is kept closed and the fan of the unit is reversed, so that the fan inhales the hot air that has passed through the heat exchange of the adjacent unit tube bundle and forms a local heat cycle, thereby heating the heat exchange tube bundle of the unit.

[0017] The beneficial effects of the present invention are:

[0018] 1. The air-cooled condenser antifreeze device provided by the present invention has four optional operating modes with different principles and effects according to different environmental conditions, so as to achieve efficient antifreeze while ensuring the heat exchange performance of the air-cooled condenser as much as possible;

[0019] 2. Each anti-freeze mode does not use external heat source, and there is no other consumption except the electric control of the blinds, so the economy is very good.

[0020] 3. When renovating existing equipment, automatic or manual precise control can be achieved by adding control functions to the owner's original air cooler DCS system, utilizing the original sensors inside the air condenser system (turbine exhaust port temperature transmitter, turbine exhaust port pressure transmitter, condensate temperature transmitter, exhaust port temperature transmitter), as well as the newly added air inlet side air temperature transmitter and electric shutter opening adjustment.

[0021] 4. The working principle and structure of the antifreeze device can be fully applied to the antifreeze modification of existing blast-type air-cooled condensers. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the three-dimensional structure of the device described in an embodiment of the present invention.

[0023] Figure 2 yes Figure 1 Schematic diagram of the three-dimensional structure behind the colored steel plate of the windbreak wall.

[0024] Figure 3 yes Figure 1 Schematic diagram of the three-dimensional structure behind the hidden windbreak wall color steel plate, wind chamber and air-conditioning condenser support components.

[0025] Figure 4 yes Figure 1 Schematic diagram of the three-dimensional structure after hiding some components above the wind turbine platform.

[0026] Figure 5 yes Figure 1 Schematic diagram of the three-dimensional structure behind the fan, with some components above the fan platform and the fan hidden (only the internal structure of the wind chamber is shown).

[0027] Figure 6 yes Figure 1 Schematic diagram of the longitudinal cross-section structure.

[0028] Figure 7 It is a schematic diagram of the airflow effect of one of the working modes of the device described in an embodiment of the present invention.

[0029] Figure 8 Schematic diagram of the airflow effect of the second working mode of the device according to the embodiment of the present invention.

[0030] Figure 9 Schematic diagram of three airflow effects in the working mode of the device according to an embodiment of the present invention.

[0031] Figure 10 Schematic diagram of four airflow effects of the device working mode according to an embodiment of the present invention.

[0032] Numbers in the figure:

[0033] 1. Windbreak wall; 2. Steam distribution pipe; 3. First electric shutter; 4. Fan platform; 4.1. Second electric shutter; 4.2. Platform support structure; 4.3. Slope side walkway; 4.4. Gable side walkway; 5. Heat exchange tube bundle; 6. Air chamber; 6.1. Third electric shutter; 6.2. Fourth electric shutter; 6.3. Air temperature transmitter; 6.4. Lower support structure; 7. A-type frame; 7.1. Inspection window; 7.2. Internal passage door; 7.3. Sealing plate; 8. Fan; 9. Air duct; 10. Fan bridge; 11. Fan drive system. DETAILED DESCRIPTION

[0034] The following is further described with reference to the embodiments shown in the accompanying drawings.

[0035] Problems and causes of frozen pipes in conventional air-cooled condensers in winter:

[0036] An air-cooled condenser (AC) is a negative pressure device that generates and maintains low back pressure at the turbine outlet through steam condensation. The inlet working steam of the AC is saturated wet steam after the turbine has performed work. Under normal ambient temperature and operating conditions, air is blown through the finned tube bundle by a fan. The heat exchange in the finned tubes removes the heat from the steam inside the tubes, causing the steam to condense into water. An AC generally adopts a two-flow design. The finned tube bundle is divided into a downstream bundle (steam enters from the top of the bundle) and a countercurrent bundle (steam enters from the bottom of the bundle) in a certain ratio. Steam first flows through the downstream bundle for condensation, and uncondensed steam continues to flow into the countercurrent bundle for further condensation. The remaining non-condensable gases are eventually extracted by an exhaust evacuator at the top of the countercurrent bundle.

[0037] Due to the correlation between saturated steam temperature and pressure, and the generally small heat exchange margin in air-cooled condensers, the temperature difference between the condensate at the tube outlet and the saturated steam is generally small (generally within 3°C). However, in winter, at low temperatures (below 0°C), the temperature difference between the steam inside the tube bundle and the external air increases, and the heat exchange capacity of the air-cooled condenser increases, causing most of the saturated steam to condense in the upper finned tube area of ​​the downstream tube bundle. The lower part of the downstream finned tubes is almost entirely condensed water. At this time, the lower part of the finned tubes of the air-cooled condenser tube bundle directly exchanges heat with the condensate, causing the condensate temperature to drop. When the ambient temperature reaches the critical point, the condensate in the lower part of the downstream tube bundle will freeze. At low temperatures, the enhanced heat exchange performance of the downstream tube bundle in the first flow path will further reduce the steam content in the countercurrent tube bundle in the second flow path, making the surface temperature of the countercurrent tube bundle lower than that of the downstream tube bundle, making the condensate in the countercurrent tube bundle more susceptible to freezing. The freezing of some condensate will cause the steam flux of the tube bundle where it is located to further reduce, further aggravating the freezing of condensate, and eventually causing some finned tubes to completely freeze and block the tubes. In severe cases, the finned tubes will burst, causing the air-to-air condenser to leak and the back pressure to increase, eventually leading to turbine shutdown.

[0038] At the same time, due to the accumulation of non-condensable gases and excessive heat exchange, air-to-air condensers are more susceptible to uneven steam distribution on both sides of the A-type tube bundles in winter (once occurring, this phenomenon gradually intensifies). This causes partial overcooling of the tube bundle on the side with less steam, making frozen pipes more likely. To prevent frozen pipes on the overcooled side, users often significantly reduce fan speed or even shut down the unit. This reduced heat exchange capacity increases turbine back pressure, preventing optimal turbine output from being achieved, resulting in reduced plant production capacity. Furthermore, there is no guarantee that frozen pipes will not occur in air-to-air condensers.

[0039] The A-type air-cooled condenser shown in the accompanying drawings comprises a lower support structure fixed to a hardened foundation, an air chamber fixed to the lower support structure, and an air-cooling unit mounted on top of the air chamber (two air-cooling units are shown in the schematic diagram; each air-cooling unit is provided with a set of fans); in the air-cooling unit, an A-shaped frame 7 stands on top of the air chamber; a plurality of heat exchange tube bundles 5 consisting of a plurality of finned tubes arranged in parallel with each other are laid from top to bottom on two inclined slopes of the A-shaped frame (each tube bundle generally consists of 30-55 finned tubes, and each air-cooling unit generally contains 6-10 tube bundles; a plurality of horizontal beams are also fixed to the A-shaped frame 7 to increase the overall stability of the frame, and the steam distribution pipe 2 It is installed at the top of the A-shaped frame. Two junction boxes 7.4 are respectively installed at the bottom of the two inclined slopes. The slope between the junction boxes and the fan platform is sealed with a sealing plate 7.3. The gable of the A-shaped frame is a partition made of color steel plate, which is equipped with an inspection window 7.1 and an internal access door 7.2. The top of the wind chamber is the fan platform 4. The middle part of the fan platform is equipped with a fan 8 with a wind tube 9. The fan platform is surrounded by a walkway. The fan drive system 11 is installed on the fan above the fan. The bridge 10 drives the fan 8 to blow air toward the heat exchange tube bundle. The fan drive system and various sensors are connected to and controlled by the air cooler DCS (the existing air cooler DCS itself includes some steam turbine DCS data). The air cooler is also enclosed by a windshield 1 (with the walkway located within the windshield) to maintain the air cooler's normal operating environment and prevent unnecessary external circulation of hot air. The fan drive system includes a motor (preferably a variable frequency motor) and a gearbox.

[0040] The above structure is similar to the existing blast-type A-type air-cooled condenser.

[0041] In order to solve the problem of frozen pipes in air-cooled condensers, the present invention is equipped with an air-cooled condenser antifreeze device with multiple optional working modes and controllable performance on the air-cooled condenser; wherein: a plurality of fourth electric shutters 6.2 are installed on the walls around the air chamber (the fourth electric shutters need to cover all the walls around the air chamber); a plurality of third electric shutters 6.1 are installed in the lower part of the air chamber and seal the bottom of the air chamber (the third electric shutters need to seal the entire bottom of the air chamber); a plurality of second electric shutters 4.1 are laid correspondingly below the slope side walkways 4.3 (the second electric shutters are laid below all slope side walkways); the fourth electric shutters, the third electric shutters and the second electric shutters are all connected to the air cooler DCS system for unified control.

[0042] The air chamber is also equipped with several air temperature transmitters 6.3 (by Figure 5 It can be seen that a short column stands in the air chamber, and an air temperature transmitter is installed on the short column); the air temperature transmitter is electrically connected to the air cooler DCS system to obtain temperature data.

[0043] The device also includes a first electric shutter covering the upper portion of the heat exchange tube bundle on the leeward side of the air-cooled condenser, and the first electric shutter is also connected to the air-cooler DCS system. By adjusting the shutter opening and intermediate state, the cooling air volume of the upper portion of the heat exchange tube bundle is controlled (reducing the opening of the first electric shutter can reduce the air volume passing through the upper portion of the tube bundle, thereby weakening the heat exchange capacity of the upper portion of the tube bundle; when the first electric shutter is fully closed, the heat exchange capacity of the upper portion of the tube bundle is the lowest, so that most of the steam passing through the tube bundle does not condense in the upper portion of the tube bundle and maintains the temperature. At the same time, the fan can be forced to blow air out of the lower portion of the tube bundle to establish the hot air circulation of working modes three and four).

[0044] The walkway around the fan platform is formed by connecting two gable side walkways 4.4 on the gable side and two slope side walkways 4.3 on the slope side; the gable side walkways are paved with patterned steel plates with excellent sealing performance to ensure sealing performance; the slope side walkways 4.3 are paved with grille plates to ensure ventilation performance; the second electric blinds are laid in the space below the grille plates to avoid affecting the walkway traffic.

[0045] The vertically installed shutters around the air chamber and the horizontally installed shutters on the platform are fixed with bolts. If necessary in summer, they can be temporarily removed to ensure that there is no adverse effect on the static pressure on the air inlet side.

[0046] The above performance controllable air-cooled condenser antifreeze device can adopt the following antifreeze working mode ( Figures 7 to 10 The cold airflow in the air is represented by solid arrows; the hot airflow is represented by dashed arrows):

[0047] The first (see Figure 7 When antifreeze requirements are relatively low, the ambient temperature is below 0°C, and the air cooler DCS indicates a subcooling greater than 3°C (subcooling is the difference between the turbine exhaust temperature and the condensate outlet temperature; its value directly indicates whether the condensate in the tube bundle is subcooled, the same applies below). Increase the static pressure on the fan inlet side: First, reduce the fan speed to its minimum operating speed (generally, by adjusting the VFD to 20% of the rated speed). Close the third electric shutter 6.1 at the bottom of the air plenum. Simultaneously, adjust the opening of the fourth electric shutter 6.2 on the surrounding walls of the air plenum in the same proportion. As the ambient temperature drops, the opening of these shutters can be further reduced to the minimum setting (a 10% opening is required to meet basic inlet air heat exchange requirements). At this time, keep the second electric shutter 4.1 closed and the first electric shutter 3 100% open.

[0048] The basic principle of this mode is to maintain the minimum fan speed while increasing the static pressure on the air inlet side, reducing the air volume on the air inlet side of the heat exchange tube bundle, thereby reducing the overall heat transfer capacity of the tube bundle and maintaining normal operation of the air-to-condenser. This mode is recommended for use in outdoor ambient temperatures between 0°C and -15°C.

[0049] The second (see Figure 8 ): When the ambient temperature continues to drop and antifreeze capacity needs to be increased (after the first antifreeze mode is activated, the air cooler DCS system again indicates a subcooling degree greater than 3°C), the operating mode of increasing the static pressure of the air outside the upper tube bundle is adopted: the air plenum is set to the first operating mode, closing the third electric shutter 6.1 at the lower part of the air plenum and maintaining the fourth electric shutter 6.2 at a minimum opening of 10%. At the same time, the second electric shutter 4.1 is kept closed; and the opening of the first electric shutter 3 is gradually reduced until it is closed (when the first electric shutter 3 is closed, the heat exchange capacity of the upper half of the heat exchange tube bundle is basically eliminated, retaining only the heat exchange capacity of the lower half of the tube bundle).

[0050] The basic principle of this mode is to maintain the minimum fan speed while increasing the static pressure outside the upper tube bundle, reducing the air flow to the upper heat exchange tube bundle until it is completely cut off. This reduces the overall heat transfer capacity of the tube bundle and maintains the normal operation of the air-to-condenser. This mode is recommended for outdoor ambient temperatures between -10°C and -25°C.

[0051] The third (see Figure 9 ): When the ambient temperature continues to drop and the first electric shutter 3 is already closed but additional antifreeze capability is still required (the DCS system again indicates that the subcooling degree is greater than 3°C), hot air internal circulation operating mode 1 is adopted: the air chamber is set to the second operating mode, closing the third electric shutter 6.1 and maintaining the fourth electric shutter 6.2 at a minimum opening of 10%, and keeping the first electric shutter 3 closed; at this time, the second electric shutter 4.1 is opened, so that the air passages under the two sloped side walkways 4.3 are open. Under the action of the suction force under the fan, a portion of the hot air that has passed through the heat exchange of the tube bundle can be re-inhaled into the air chamber through the walkways on both sides, thereby continuously heating the air entering the tube bundle.

[0052] When the data meets the antifreeze requirement, the opening of the second electric shutter 4.1 is adjusted (priority is given to controlling the second electric shutter 4.1; reducing the opening can increase the static pressure in the aisle air passage and weaken the hot air circulation, but it cannot be completely closed and must be maintained at least 20% open to ensure the establishment of the hot air circulation) and the opening of the first electric shutter 3 (which can increase the air intake volume of the upper heat exchange tube bundle while reducing the air volume participating in the hot air circulation) to keep the hot air circulation temperature relatively stable, thereby achieving antifreeze while ensuring stable heat exchange performance of the air-conditioning condenser.

[0053] The basic principle of this mode is to establish a hot air internal circulation channel, putting the ACC into hot air internal circulation antifreeze mode. This prevents freezing by raising the temperature of the circulating air. Simultaneously, the ACC's antifreeze and heat exchange capabilities are stabilized by controlling the second electric shutter 4.1 in the aisle air passage and the first electric shutter 3, which controls the heat exchange capacity of the upper tube bundle. This mode is recommended for outdoor temperatures below -20°C.

[0054] As the outside temperature gradually drops and the subcooling data in the DCS system is used to determine, the air-cooled condenser antifreeze device can sequentially adopt the above three antifreeze working modes.

[0055] The fourth special mode (see Figure 10 ): When there are multiple fan units in the same column of the air-cooled condenser ( Figure 10 The figure shows the case of two fan units, A and B, arranged in parallel. If one of the units, such as unit A, is overcooled, hot air internal circulation operating mode two is adopted: the air chamber is set according to the first operating mode, with the third electric shutter 6.1 closed and the fourth electric shutter 6.2 maintained at a minimum opening of 10%. The first electric shutter 3 and second electric shutter 4.1 of subcooling unit A are also kept closed, and the fan of subcooling unit A is reversed (so that the airflow in this unit flows from top to bottom). At this time, a cross-unit hot air circulation is formed between unit A and the units on both sides. The hot air from the tube bundle outlets of the two units is drawn into unit A, heating the tube bundle of unit A. At the same time, some of the hot air flows out of the air cooling island through the air chamber shutter 6.2 at the bottom of unit A, while the rest is drawn into the fans of the two units on both sides, completing the circulation.

[0056] When unit A achieves the antifreeze effect, it can switch to the other three antifreeze working modes.

[0057] Unique features of this invention (compared with existing similar or similar technologies):

[0058] 1. The antifreeze device adopts a wind chamber with shutters laid vertically on four sides and horizontally on the bottom, a ventilated walkway with built-in shutters, shutters on the upper part of the tube bundle and other structures, and is used with frequency conversion motors, blower fans, temperature transmitters and other sensors, and automatic or manual control.

[0059] 2. There are four antifreeze modes with different principles available;

[0060] The most appropriate overall antifreeze mode can be selected based on ambient temperature changes and supercooling data;

[0061] 3. Support local antifreeze mode for overcooling of specific fan units;

[0062] 4. When the antifreeze device is in use, the opening of the electric shutters is adjusted according to different positions, which has the ability to accurately control the temperature and ensure that the heat exchange performance of the air-cooled condenser is not affected.

Claims

1. A performance-controllable air-cooled condenser antifreeze device, comprising an air chamber (6) fixed by a lower support structure, a fan platform (4) located on the top of the air chamber and supported by the lower support structure, a walkway arranged around the fan platform, a fan (8) and a fan drive mechanism (11) installed on the air-cooled condenser fan platform, and an air-cooled condenser DCS system electrically connecting the drive mechanism and various sensors. The device is characterized in that: The device also includes a plurality of fourth electric shutters (6.2) installed on the walls around the wind chamber, a plurality of third electric shutters (6.1) installed at the lower part of the wind chamber, and a plurality of second electric shutters (4.1) installed below the walkway; the fourth electric shutters, the third electric shutters, and the second electric shutters are all electrically connected to the air cooler DCS system; The device also includes a first electric shutter (3) covering the upper half of the heat exchange tube bundle on the leeward side of the air-cooled condenser and electrically connected to the DCS system of the air-cooler; by adjusting the opening and closing and intermediate states of the first electric shutter, the cooling air volume of the upper half of the heat exchange tube bundle is controlled; The walkway is formed by connecting two gable side walkways (4.4) and two slope side walkways (4.3); the gable side walkways are paved with patterned steel plates to ensure sealing, while the slope side walkways are paved with grille plates to ensure ventilation; the second electric blinds are correspondingly laid below the grille plates of the slope side walkways (4.3).

2. The performance-controllable air-cooled condenser antifreeze device according to claim 1, characterized in that: The air chamber is provided with a plurality of air temperature transmitters (6.3) electrically connected to the DCS system of the air cooler.

3. The operating mode of the performance-controllable air-cooled condenser antifreeze device according to claim 1 is as follows: As the outside temperature gradually drops and the subcooling data in the air cooler DCS system is used to determine, the air cooler antifreeze device can sequentially adopt the following three antifreeze working modes: The first method: When the ambient temperature is below 0°C and the DCS system of the air cooler indicates that the degree of subcooling is greater than 3°C, the third electric shutter at the bottom of the air chamber is closed, and the fourth electric shutter on the walls around the air chamber are adjusted in the same proportion; the opening of the fourth electric shutter is controlled to a minimum of 10%; the second electric shutter is kept closed and the first electric shutter is kept 100% open; The second method: After the first working mode is put into use, when the DCS system of the air cooler again shows that the subcooling degree is greater than 3°C, close the third electric shutter at the bottom of the air chamber and keep the fourth electric shutter at a minimum opening of 10%, while keeping the second electric shutter closed; control the opening of the first electric shutter to the minimum of closed; The third mode: After the second working mode is put into use, when the DCS system of the air cooler again shows that the subcooling degree is greater than 3°C; close the first electric shutter; close the third electric shutter and maintain the minimum opening of the fourth electric shutter at 10%; open and control the opening of the second electric shutter to a minimum of 20%.

4. The operating mode of the performance-controllable air-cooled condenser antifreeze device according to claim 3 is characterized by: When there are multiple fan units in the same row of the air-cooled condenser and one of the units is overcooled, close the third electric shutter of the unit and keep the fourth electric shutter at a minimum opening of 10%, keep the first electric shutter of the unit closed, keep the second electric shutter of the unit closed and reverse the fan of the unit, so that the fan draws in the hot air that has passed through the heat exchange of the tube bundle of the adjacent unit and forms a local heat cycle, thereby heating the heat exchange tube bundle of the unit.

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