An intelligent anti-freezing system and method applied to an air-cooled island

Abstract

An intelligent anti-freezing system and method for an air-cooled island, an anti-freezing device for the countercurrent area, an anti-freezing device for the downstream area, an intelligent anti-freezing control system, and an infrared thermal imager for detecting the heat exchange condition of the finned tubes on both sides of the cooling unit; the infrared thermal imager is connected to the intelligent anti-freezing control system, and the intelligent anti-freezing control system is connected to the anti-freezing device for the countercurrent area and the anti-freezing device for the downstream area. By dividing the air-cooled finned tubes into a high freezing risk area, a medium freezing risk area, and a low freezing risk area, and adopting a zoning anti-freezing strategy, the present invention solves the problem of inconsistent anti-freezing effects in the existing countercurrent and downstream areas. By using the intelligent anti-freezing control system, the deployment length of the anti-freezing electric heating insulation curtain and the heat generation amount of the electric heating belt in the anti-freezing electric heating insulation curtain are finely controlled, so as to keep the temperature of the condensed water inside the air-cooled finned tubes above the freezing temperature, achieving an optimized anti-freezing effect.

Description

Technical Field

[0001] The present invention belongs to the field of air-cooled island anti-freezing, and relates to an intelligent anti-freezing system and method applied to an air-cooled island. Background Art

[0002] Direct air-cooled generating units are widely distributed in the northern regions of China. Such units use air as a heat exchange medium to cool the exhaust steam of steam turbines. In recent years, due to the increasing demand for deep peak shaving during the heating season, many power plants have carried out flexibility transformations, resulting in the long-term operation of the air-cooled island under low-flow conditions. At this time, the steam inlet volume of the air-cooled island is much smaller than the minimum designed steam inlet volume of the air-cooled island, greatly increasing the risk of pipe freezing in the air-cooled island in winter. Summary of the Invention

[0003] To overcome the above deficiencies, the purpose of the present invention is to propose an intelligent anti-freezing system and method applied to an air-cooled island, which has characteristics such as intelligent recognition, automatic adjustment, and good anti-freezing effect.

[0004] To achieve the above purpose, the present invention adopts the following technical solutions:

[0005] An intelligent anti-freezing system applied to an air-cooled island includes an anti-freezing device for the counter-current area, an anti-freezing device for the co-current area, an intelligent anti-freezing control system, and an infrared thermal imager for detecting the heat exchange situation of the finned tubes on both sides of the cooling unit; the infrared thermal imager is connected to the intelligent anti-freezing control system, and the intelligent anti-freezing control system is connected to the anti-freezing device for the counter-current area and the anti-freezing device for the co-current area.

[0006] A further improvement of the present invention is that the anti-freezing device for the counter-current area and the anti-freezing device for the co-current area have the same structure. The anti-freezing device for the counter-current area includes an anti-freezing electric heating thermal insulation curtain, a crank-link mechanism, and a motor. The anti-freezing electric heating thermal insulation curtain is arranged on a horizontal shaft, the horizontal shaft is connected to the crank-link mechanism, and the crank-link mechanism is connected to the motor.

[0007] A further improvement of the present invention is that the anti-freezing electric heating thermal insulation curtain is made of a heat-insulating cotton material with a porous structure.

[0008] A further improvement of the present invention is that a waterproof electric heating tape is arranged in the heat-insulating cotton material.

[0009] A further improvement of the present invention is that the anti-freezing device for the counter-current area is arranged above the air-cooling unit, and the anti-freezing device for the co-current area is arranged below the air-cooling unit.

[0010] A further improvement of the present invention is that the infrared thermal imager is arranged above the air-cooling unit fan.

[0011] An anti-freezing method for the intelligent anti-freezing system applied to the air-cooled island based on the above, divides the air-cooled finned tubes into high freezing risk areas, medium freezing risk areas and low freezing risk areas, and quantifies the positions of the boundaries of different areas at the same time. The intelligent anti-freezing control system uses an image recognition algorithm to extract the boundaries of different temperature layers in the image generated by the infrared thermal imager, and calculates the anti-freezing heat required for different areas; realizes the anti-freezing heat required for different areas through a waterproof heating cable.

[0012] A further improvement of the present invention is that the low-risk freezing area is the steam flow area of the air-cooled finned tubes, the medium-risk area is the condensation area in the air-cooled finned tubes, and the high-risk freezing area is the supercooled area of the air-cooled finned tubes.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention realizes intelligent identification and automatic adjustment through the setting of an anti-freezing device in the countercurrent area, an anti-freezing device in the downstream area, an intelligent anti-freezing control system and an infrared thermal imager; the infrared thermal imager is connected to the intelligent anti-freezing control system, and the intelligent anti-freezing control system is connected to the anti-freezing device in the countercurrent area and the anti-freezing device in the downstream area, and has a good anti-freezing effect. The present invention uses an anti-freezing electric heating insulation curtain for anti-freezing of air-cooled finned tubes, and has a lower technical cost than existing technologies such as rolling doors and shutters.

[0014] Furthermore, the anti-freezing electric heating insulation curtain is made of a high-performance heat-insulating cotton material with a porous structure, and is internally provided with a waterproof heating cable, and the heat generation of the waterproof heating cable is controllable, ensuring normal operation even in rainy and snowy weather.

[0015] The present invention divides the air-cooled finned tubes into high freezing risk areas, medium freezing risk areas and low freezing risk areas, adopts a zoning anti-freezing strategy, and solves the problem of inconsistent anti-freezing effects in the countercurrent and downstream areas of the prior art. The anti-freezing electric heating insulation curtain is only laid on the hydrophobic cooling section of the air-cooled finned tubes, and there is no need to lay it on the steam condensation section without freezing risk, reducing investment waste. By using an intelligent anti-freezing control system, the deployment length of the anti-freezing electric heating insulation curtain and the heat generation of the heating cable in the anti-freezing electric heating insulation curtain are finely controlled, keeping the temperature of the condensed water inside the air-cooled finned tubes above the freezing temperature, achieving an optimized anti-freezing effect. Brief Description of the Drawings

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

[0017] Figure 2 is a structural schematic diagram of the anti-freezing electric heating insulation curtain.

[0018] Wherein, 1. Anti-freezing device in the countercurrent area; 2. Anti-freezing device in the downstream area; 3. Anti-freezing electric heating insulation curtain; 4. Crank link; 5. Motor; 6. Infrared thermal imager; 7. Intelligent anti-freezing control system; 8. Heat-insulating cotton material; 9. Waterproof heating cable. Specific Embodiments

[0019] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0020] See Figure 1 and Figure 2 The present invention includes seven parts: an anti-freezing device 1 for the countercurrent zone, an anti-freezing device 2 for the co-current zone, an anti-freezing electric heating insulation curtain 3, a crank and connecting rod 4, a motor 5, an infrared thermal imager 6, and an intelligent anti-freezing control system 7. Among them, the anti-freezing device 1 for the countercurrent zone and the anti-freezing device 2 for the co-current zone have the same structure. The anti-freezing device 1 for the countercurrent zone includes an anti-freezing electric heating insulation curtain 3, a crank and connecting rod 4, and a motor 5, and can realize automatic adjustment. The infrared thermal imager 6 and the intelligent anti-freezing control system 7 constitute a control center, and control the anti-freezing device through real-time calculation and analysis.

[0021] The anti-freezing devices are arranged in the countercurrent zone and the co-current zone respectively according to the characteristics of the air-cooled unit. The arrangement methods in the co-current zone and the countercurrent zone are different. Among them, the countercurrent zone is arranged above the air-cooled unit, and the anti-freezing electric heating insulation curtain 3 unfolds from top to bottom; the co-current zone is arranged below the air-cooled unit, and the anti-freezing electric heating insulation curtain 3 unfolds from bottom to top. That is, different measures are adopted for anti-freezing in the co-current zone and the countercurrent zone of the air-cooled unit.

[0022] The anti-freezing electric heating insulation curtain 3 is made of a high-performance thermal insulation cotton material 8 with a porous structure. A waterproof electric heating belt 9 is arranged in the thermal insulation cotton material 8, and the heat generation of the waterproof electric heating belt 9 is controllable to ensure normal operation even in rainy and snowy weather.

[0023] The anti-freezing electric heating insulation curtain 3 is supported by a horizontal shaft, which is connected to the crank and connecting rod 4. The motor 5 drives the crank and connecting rod 4 to push the anti-freezing electric heating insulation curtain 3 to realize unfolding and contraction.

[0024] The length of the anti-freezing electric heating insulation curtain only needs to cover the area with a relatively high risk of freezing in the finned tubes, and does not need to cover all the finned tubes.

[0025] The infrared thermal imager 6 can detect the heat exchange situation of the finned tubes on both sides of the cooling unit in all directions of 360°. The infrared thermal imaging information taken every 5 minutes is fed back to the intelligent anti-freezing control system 7 for data analysis. The intelligent anti-freezing control system 7 controls the opening degree of the anti-freezing electric heating insulation curtain and the heat generation of the internal electric heating belt in real time according to the data analysis results to realize anti-freezing optimization.

[0026] The intelligent anti-freezing control system 7 is equipped with a high-performance computer. By regularly transmitting the images captured by the infrared thermal imager 6 to the intelligent control system 7, the heat exchange situation of the air-cooled unit is analyzed through an image recognition algorithm. Then, according to the current heat exchange situation of the air-cooled unit and the analysis results, the unfolding size of the anti-freezing electric heating insulation curtain and the heat generation of the electric heating belt in the insulation curtain are adjusted to optimize the anti-freezing effect. The infrared thermal imager is installed above the air-cooled unit fan and can operate normally in weather such as rain, snow, and strong wind. The present invention can solve the winter anti-freezing problem of the air-cooled unit under the small-flow condition of the air-cooled island, and can realize automatic adjustment and optimize the anti-freezing effect.

[0027] Specifically, the air-cooled finned tubes are divided into high-freezing-risk areas, medium-freezing-risk areas, and low-freezing-risk areas, and at the same time, the positions of the boundaries of different areas are quantified. The intelligent anti-freezing control system 7 uses an image recognition algorithm to extract the boundaries of different temperature layers in the image generated by the infrared thermal imager 6 and calculates the anti-freezing heat required for different areas; the anti-freezing heat required for different areas is realized through a waterproof electric heating belt. Increase the heat generation of the electric heating belt in the high-freezing-risk area to prevent the finned tubes from freezing; reduce the heat generation of the electric heating belt in the low-freezing-risk area to reduce energy consumption. At the same time, increase the heat generation of the electric heating belt in the easily frozen area to prevent the finned tubes from freezing; reduce the heat generation of the electric heating belt in the relatively high-temperature and safer area to reduce energy consumption.

[0028] Among them, the low-risk freezing area is the steam flow area of the air-cooled finned tubes. The freezing risk in this area is extremely small, and only the regional changes need to be observed to determine the boundary between this area and the medium-risk freezing area. The medium-risk area is the condensation area in the air-cooled finned tubes. This area is a steam-water mixing area, and its characteristic is that the temperature in this area is consistent. Liquid water initially appears in this area, and the freezing risk increases, so it needs to be protected to prevent the area from shrinking. The high-risk freezing area is the supercooled area of the air-cooled finned tubes. The condensed water flowing in the tubes in this area is supercooled, and the freezing risk is relatively high, so it needs to be key protected.

[0029] According to the size and heat exchange characteristics of different areas, the required air-cooling anti-freezing amount is calculated and realized by controlling the heat generation of the electric heating belt through the intelligent anti-freezing control system.

[0030] The heat generation of the electric heating belt in the anti-freezing electric heating insulation curtain 3 is automatically controlled according to the analysis results of the energy control system 7, and the temperature of the condensed water in the air-cooled finned tubes is always controlled above the freezing temperature, achieving a precise control effect and reducing unnecessary energy waste.

Claims

1. An intelligent anti-freezing system applied to an air-cooled island, characterized in that, It includes an anti-freezing device (1) for the countercurrent area, an anti-freezing device (2) for the concurrent flow area, an intelligent anti-freezing control system (7), and an infrared thermal imager (6) for detecting the heat exchange condition of the finned tubes on both sides of the cooling unit; the infrared thermal imager (6) is connected to the intelligent anti-freezing control system (7), and the intelligent anti-freezing control system (7) is connected to the anti-freezing device (1) for the countercurrent area and the anti-freezing device (2) for the concurrent flow area; The anti-freezing device (1) for the countercurrent area and the anti-freezing device (2) for the concurrent flow area have the same structure. The anti-freezing device (1) for the countercurrent area includes an anti-freezing electric heating insulation curtain (3), a crank connecting rod (4), and a motor (5). The anti-freezing electric heating insulation curtain (3) is arranged on a horizontal shaft, the horizontal shaft is connected to the crank connecting rod (4), and the crank connecting rod (4) is connected to the motor (5); the motor (5) drives the crank connecting rod (4) to push the anti-freezing electric heating insulation curtain (3) to achieve unfolding and contraction; the anti-freezing device (1) for the countercurrent area is arranged above the air-cooling unit, and its anti-freezing electric heating insulation curtain (3) unfolds from top to bottom. The anti-freezing device (2) for the concurrent flow area is arranged below the air-cooling unit, and its anti-freezing electric heating insulation curtain (3) unfolds from bottom to top; An intelligent anti-freezing control system is adopted to precisely control the unfolding length of the anti-freezing electric heating insulation curtain and the heat generation of the waterproof electric heating belt in the anti-freezing electric heating insulation curtain, and keep the temperature of the condensed water inside the air-cooling finned tubes above the freezing temperature.

2. The intelligent anti-freezing system applied to an air-cooled island according to claim 1, wherein, The anti-freezing electric heating insulation curtain (3) is made of a heat-insulating cotton material (8) with a porous structure.

3. The intelligent anti-freezing system applied to an air-cooled island according to claim 2, wherein, A waterproof electric heating belt (9) is arranged in the heat-insulating cotton material (8).

4. The intelligent anti-freezing system applied to an air-cooled island according to claim 1, characterized in that The infrared thermal imager (6) is arranged above the air-cooling unit fan.

5. An anti-freezing method for the intelligent anti-freezing system applied to an air-cooled island according to claim 1, characterized in that, The air-cooling finned tubes are divided into a high freezing risk area, a medium freezing risk area, and a low freezing risk area. At the same time, the positions of the boundaries of different areas are quantified. The intelligent anti-freezing control system (7) uses an image recognition algorithm to extract the boundaries of different temperature layers in the image generated by the infrared thermal imager (6), and calculates the anti-freezing heat required for different areas; the anti-freezing heat required for different areas is realized through the waterproof electric heating belt; the low-risk freezing area is the steam flow area of the air-cooling finned tubes, the medium-risk area is the condensation area in the air-cooling finned tubes, and the high-risk freezing area is the supercooling area of the air-cooling finned tubes.

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