An indirect cooling tower freeze protection monitoring system and method

Abstract

The present application relates to the technical field of thermal power plant monitoring, in particular to an inter-cooling tower anti-freezing monitoring system and method, comprising: a bottom monitoring device and a top monitoring device; the bottom monitoring device comprises a pair of dual-spectrum cameras, which are respectively arranged on two bottom corners of the triangular unit and shoot the heat exchange tube bundle; the top monitoring device comprises a pair of dual-spectrum cameras, which are respectively arranged on two bottom corners of the triangular unit and shoot the heat exchange tube bundle; and a control system determines the freezing fault point according to the collected images. In view of the problem that the inter-cooling tower monitoring scheme in the prior art cannot determine the local cold spot in the fluid environment, multiple dual-spectrum cameras are arranged at positions where the heat exchange tube bundle plate is prone to freezing, and the local cold spot is determined by shooting dual-spectrum images and analyzing, so that the monitoring effect is improved.

Description

Technical Field

[0001] This invention relates to the field of thermal power plant monitoring technology, specifically to an anti-freezing monitoring system and method for intercooled towers. Background Technology

[0002] Indirect cooling towers, also known as indirect cooling towers, are cooling devices primarily used in power plants. Taking a typical thermal power plant as an example, indirect cooling towers are often used in thermal power units to cool the exhaust steam from the turbine, achieving indirect cooling through circulating water as an intermediate medium. The core principle is: the exhaust steam is cooled by circulating water in the condenser; the heated circulating water is pumped to the indirect cooling tower, where it exchanges heat with the cold air flowing upwards from the bottom of the tower in a cooling triangle, thus achieving cooling. The cooled circulating water then returns to the condenser, completing a closed loop. Compared to common cooling towers that dissipate heat based on water evaporation, the closed cooling water loop of the indirect cooling tower significantly reduces water consumption, making it widely used in inland areas. However, when indirect cooling towers are used in sub-zero environments, the water flow velocity and temperature within the heat exchange tube bundle can change with operating conditions, potentially leading to icing problems and tube bundle rupture, terminating the circulation.

[0003] To address this issue, similar antifreeze solutions already exist in existing technologies.

[0004] For example, patent application CN202210441629.4 discloses an antifreeze regulation system for an indirect air-cooled tower, an indirect air-cooled tower, and a regulation method. The antifreeze regulation system includes: a controller, multiple regulating valves, and multiple temperature detector groups. Each regulating valve is connected to the heat exchange inlet pipe in each air-cooled heat exchange zone of the indirect air-cooled tower. Each temperature detector group is used to detect the temperature of the heat exchange inlet pipe, heat exchange return pipe, and water in the heat exchange unit in each air-cooled heat exchange zone of the indirect air-cooled tower. Each temperature detector group and each regulating valve are electrically connected to the controller, which controls the opening degree of the regulating valves and the opening degree of the louvers of the indirect air-cooled tower according to the temperature detected by the temperature detector groups. Through the dual coordinated regulation of the regulating valves and louvers, the risk of cooling water freezing in the indirect air-cooled tower is effectively reduced, and the antifreeze capability of the indirect air-cooled tower is improved.

[0005] For example, patent application CN202510691972.8 discloses an intelligent monitoring system for the temperature field of an indirect cooling tower, relating to the field of temperature monitoring technology. It includes intelligent monitoring components and an indirect cooling tower body. The intelligent monitoring components are pre-installed at multiple locations on the sidewall of the indirect cooling tower body. The intelligent monitoring components include a wireless temperature sensor module, a data transmission module, a data processing and analysis module, an alarm module, a display module, and a cooling triangle. This application, by deploying an indirect cooling tower temperature monitoring system based on wireless temperature measurement technology on the indirect cooling tower body, can automate the temperature inspection of each sector, improve the safety management capabilities of the equipment, comprehensively monitor the cooling triangles of each sector, effectively prevent tube bundle freezing and cracking, accurately control the temperature of the cooling triangles, reduce the temperature of the indirect cooling circulating water, reduce the unit back pressure, and provide a reliable basis for the safe, economical, and stable operation of the unit. This avoids situations such as freezing, leakage, and shutdown of the cooling triangle heat dissipation tube bundles, thereby reducing economic losses.

[0006] However, in actual implementation, the inventors found that since the water flow in the cooling triangle pipe is a complex fluid model with multiple nodes and variable flow velocity, measuring the temperature at only a single or a few points cannot ensure that there will be no extreme cold spots at individual points in the water circuit, which leads to the problem of insufficient monitoring effect. Summary of the Invention

[0007] In view of the above-mentioned problems in the existing technology, an antifreeze monitoring system for indirect cooling towers is provided.

[0008] The specific technical solution is as follows: A freezing protection monitoring system for an intercooling tower includes multiple sets of dual-spectrum monitoring devices and a control system; Each of the aforementioned dual-spectrum monitoring devices is installed on a triangular unit of the intercooling tower; The triangular unit consists of two sets of heat exchange tube bundles arranged at an angle. One end of each heat exchange tube bundle is abutted against the other end, and the bundles are fixed to the frame structure. The abutting end is used as the apex of the triangular unit. The dual-spectrum monitoring device includes a bottom monitoring device and a top monitoring device; The bottom monitoring device includes a pair of dual-spectrum cameras, which are respectively set at the two bottom corners of the triangular unit and take pictures of the bottom area of ​​the heat exchange tube bundle; The top monitoring device includes a pair of dual-spectrum cameras, which are respectively set at the two bottom corners of the triangular unit and take pictures of the top area of ​​the heat exchange tube bundle; The control system determines the freezing fault point based on the acquired images.

[0009] On the other hand, the bottom monitoring device is installed at a height of 2.1m above the base plate of the triangular unit, and the field of view of the bottom monitoring device is set to fit the adjacent heat exchange tube bundle and the frame structure at the bottom edge.

[0010] On the other hand, the installation height of the top monitoring device is 2.1m below the top sealing plate of the triangular unit, and the field of view of the top monitoring device is set to fit the adjacent heat exchange tube bundle and the frame structure at the bottom.

[0011] A monitoring method applicable to the above-mentioned intercooling tower antifreeze monitoring system; The monitoring method includes: Step S1: Collect system operating parameters for each triangular unit to be monitored and capture bispectral images; The dual-spectral image includes a top image corresponding to the top region of the triangular unit and a bottom image corresponding to the bottom region of the triangular unit; Step S2: Match the system operating parameters to determine the system operating scenario; Step S3: Obtain the bispectral image at the corresponding location according to the system operation scenario; Step S4: Identify the frozen fault points from the bispectral image.

[0012] On the other hand, step S2 includes: Step S21: Extract the sector valve opening / closing status, circulating pump power, and power plant load power corresponding to the triangular unit from the system operating parameters; Step S22: Determine whether the current triangular unit may be in operation based on the power load of the power plant and the opening and closing status of the sector valves corresponding to the triangular unit, so as to generate operation status prediction information. Step S23: Obtain the system operation scenario based on the estimated operating status information and the power matching of the circulating pump.

[0013] On the other hand, the system operation scenario includes the early stage of operation of the indirect cooling tower, and the corresponding dual-spectral image is the top image; Step S4 includes: Step A41: Segmenting multiple tube regions from the top image; Step A42: Calculate the average pipe temperature for each of the tube bundle regions based on the infrared spectral imaging results; Step A43: Based on the average temperature of all the pipes, the tube bundle region is screened to obtain the low-temperature tube bundle region; Step A44: Locate the cold spot in the cryogenic tube bundle region as the output of the freezing fault point.

[0014] On the other hand, step A44 includes: Step A441: Based on the cryogenic tube bundle region, the top manifold extension region is segmented from the top image and then stitched together with the cryogenic tube bundle region to obtain the region to be identified; Step A442: Divide the area to be identified into multiple intervals at equal distances along the direction of liquid flow; Step A443: Calculate the average temperature for the interval to be identified, and then generate a temperature gradient sequence according to the direction of liquid flow; Step A444: Extract gradient abrupt change points from the temperature gradient sequence to determine the freezing fault point.

[0015] On the other hand, the system operation scenario includes the triangular unit stopping, and the corresponding bispectral image is the bottom image; Step S4 includes: Step B41: Acquire a series of bottom images prior to the monitoring time point, and segment the target area associated with the bottom water tank and the end of the pipe from each bottom image; Step B42: Divide the target area into temperature point windows, and stitch together the window image sequence according to the time sequence of the bottom image for each of the divided temperature point windows; Step B43: Calculate the average temperature of each frame of the window image sequence and convert it to obtain the window temperature sequence; Step B44: Perform waveform matching on the window temperature sequence to obtain the cold spot as the output of the freezing fault point.

[0016] On the other hand, in step B44, the result of the waveform matching is that the window temperature sequence moves to the freezing point after an abnormal trough appears in the matching sliding window of a preset time length.

[0017] The above technical solution has the following advantages or beneficial effects: To address the issue that existing intercooling tower monitoring solutions cannot identify localized cold spots in the fluid environment, multiple dual-spectrum cameras are installed at locations in the heat exchange tube bundle prone to freezing. By capturing and analyzing dual-spectrum images, localized cold spots can be identified, thereby improving the monitoring effect. Attached Figure Description

[0018] Embodiments of the invention will be described more fully with reference to the accompanying drawings. However, the drawings are for illustration and explanation only and do not constitute a limitation on the scope of the invention.

[0019] Figure 1 This is an overall schematic diagram of an embodiment of the present invention; Figure 2 This is a schematic diagram of the dual-spectrum camera arrangement in an embodiment of the present invention; Figure 3 This is a schematic diagram of the method in an embodiment of the present invention; Figure 4 This is a schematic diagram of step S2 in an embodiment of the present invention; Figure 5 This is a schematic diagram of step A41 in an embodiment of the present invention; Figure 6 This is a schematic diagram of step A44 in an embodiment of the present invention; Figure 7 This is a schematic diagram of step B41 in an embodiment of the present invention. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0022] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the scope of the invention.

[0023] This invention includes: A freezing monitoring system for indirect cooling towers, such as Figure 1 As shown, it includes multiple sets of dual-spectrum monitoring devices 1 and a control system 2; Each set of dual-spectrum monitoring devices is installed on a triangular unit 3 of the intercooling tower; The triangular unit 3 consists of two sets of heat exchange tube bundles 31 and 32 arranged at an angle. One end of the heat exchange tube bundles 31 and 32 abuts against the other end and is fixed to the frame structure. The abutting end is used as the apex of the triangular unit. The dual-spectrum monitoring device includes a bottom monitoring device 11 and a top monitoring device 12; The bottom monitoring device includes a pair of dual-spectrum cameras 111 and 112, which are respectively set at the two bottom corners of the triangular unit and capture images of the top area of ​​the heat exchange tube bundle; The top monitoring device includes a pair of dual-spectrum cameras 121 and 122, which are respectively set at the two bottom corners of the triangular unit and capture images of the bottom area of ​​the heat exchange tube bundle; Control system 2 determines the freezing fault point based on the acquired images.

[0024] Specifically, to address the problem that existing intercooling tower monitoring solutions cannot identify local cold spots in the fluid environment, multiple dual-spectrum cameras are installed at locations where the heat exchange tube bundle is prone to freezing. By capturing and analyzing dual-spectrum images, local cold spots can be identified, thereby improving the monitoring effect.

[0025] Specifically Figure 2 A schematic diagram of a typical triangular unit and dual-spectrum monitoring device is shown, with the example shown being the dual-spectrum cameras 111 and 112 of the bottom monitoring device.

[0026] The triangular unit is the main component of the cooling mechanism of the indirect cooling tower. In the external circulating water circuit, the triangular unit exchanges heat with the upstream turbine cooling circuit through a heat exchanger unit. After gaining heat, it enters its respective triangular unit for cooling under the action of a circulating pump.

[0027] The main components of the triangular unit are heat exchange tube bundle 31 and heat exchange tube bundle 32.

[0028] Taking the heat exchange tube bundle 31 as an example, it mainly includes: a hot water header at the bottom, whose input end is connected to the heat exchange unit and whose output end is connected to the hot water riser 311 outside the triangular unit. The hot water is distributed to each pipe through the water distributor and pushed upward by the circulation pump to reach the top header located at the top of the triangular unit.

[0029] The hot water output from each hot water riser pipe converges here and flows to the cooling tube bundle on the other side under pressure. It is then distributed into each cooling pipe 312 and descends to the bottom header under gravity. The bottom header connects to the cold water header and sends the circulating water back to the heat exchanger unit.

[0030] Since the cooling pipe 312 is located inside the triangular unit, the air in the enclosed area will form an upward airflow after exchanging heat with the hot water flowing down the cooling pipe 312, and will draw in the air at the bottom, introducing new air to continuously cool the circulating water in the cooling pipe 312.

[0031] By installing two sets of heat exchange tube bundles 31 and 32 on a specific frame and assembling them into a triangle with one end against the other, the number of heat exchange plates per unit area can be increased, thereby improving heat exchange efficiency.

[0032] For this structure, the part where the two sets of heat exchange tube bundles 31 and 32 meet is taken as the top corner, and the other two are taken as the bottom corner. At these positions, dual-spectrum cameras 111 and 112 of the bottom monitoring device are respectively set to cover the opposite heat exchange tube bundles 32 and 31.

[0033] Specifically, after simulating the flow field within the triangular unit, the inventors concluded that the hot water rising pipe is always at a high temperature and is not prone to freezing. Therefore, the main monitoring target is the inner cooling tube bundle.

[0034] These areas typically experience the following fault conditions: Analysis of freezing at the top of the triangular section: In the early stages of operation of the indirect cooling tower, the triangular units of the sector need to be filled with water. During normal operation, hot water in the hot water loop rises through the bottom of the header, driven by the circulating pump, to the header at the top of the triangular section. From there, it flows along the cold water pipe to the bottom header, and after cooling through the tube bundle, it flows into the cold water header, completing one cycle of cooling. The filling process is different. The power comes from the level difference in the high-level water tank, which "push" water from the cold and hot water pipes into the tube bundle, eventually converging at the top water header. During this process, to expel air from the tube bundle through the vent pipe of the top water header, the water in the cold water tube bundle must reach the top first. The air in the tube bundle is then forced by the water in the hot water pipe to the top header and discharged along the vent pipe. If the air cannot be completely expelled and remains in the cold water tube bundle, a potential hazard arises. For the cold water tube bundle, the unexpelled gas will move upwards, but the circulating pump pushes it downwards. The opposing forces eventually stabilize the gas in a fixed position, forming a vortex. In winter, the pipes may freeze and burst over time, causing a leak.

[0035] Analysis of the triangular base situation reveals that after the load on the user side decreases, the power plant's generator unit power decreases, and some sectors of the indirect cooling tower are withdrawn. Water in the tube bundle flows into the underground water tank under gravity. In winter, with low temperatures and reduced load, the water temperature is already low. During the flow to the underground water tank, impurities in the water slowly accumulate in the lower half of the tube bundle, some even clogging the small holes in the baffle plate. At the same time, the last part of the water forms droplets and slowly falls, accumulating on the inner wall of the tube bundle. Over time, this freezes and bursts the tube bundle.

[0036] Based on the above setup, for a single heat exchanger tube bundle, a dual-spectrum camera is installed at the top and bottom respectively to collect its dual-spectrum images. Then, a computer program analyzes the dual-spectrum images to automatically locate the freezing point, thereby achieving effective monitoring of local cold spots and avoiding the problem of insufficient measurement capacity in traditional temperature measurement methods.

[0037] Specifically, the bottom monitoring device is installed at a height of 2.1m above the base plate of the triangular unit. The field of view of the bottom monitoring device is set to fit the adjacent heat exchange tube bundle and the frame structure at the bottom edge to completely cover the heat exchange tube bundle on the opposite side.

[0038] In one embodiment, the installation height of the top monitoring device is 2.1m below the top sealing plate of the triangular unit. The field of view of the top monitoring device is set to fit the adjacent heat exchange tube bundle and the frame structure at the bottom edge to fully cover the heat exchange tube bundle on the opposite side.

[0039] A dual-spectrum camera is a surveillance camera that integrates both an infrared sensor and a white light image sensor, enabling it to generate simultaneous infrared and white light images. The infrared spectrum is primarily used to monitor temperature on the tube bundle, while the white light image helps to confirm the severity of freezing.

[0040] The dual-spectrum camera is connected to the computer in the main control room via PoE power supply, thereby enabling image transmission and power supply to the equipment. This computer is used as control system 2 and is configured with specific computer programs to analyze the images.

[0041] A monitoring method applicable to the above-mentioned intercooling tower antifreeze monitoring system; like Figure 3 As shown, the monitoring methods include: Step S1: Collect system operating parameters for each triangular unit to be monitored and capture bispectral images; The dual-spectral image includes a top image corresponding to the triangular unit and a bottom image corresponding to the bottom of the triangular unit; Step S2: Match according to system operating parameters to determine the system operating scenario; Step S3: Obtain the bispectral image at the corresponding location based on the system operation scenario; Step S4: Identify the frozen fault points from the bispectral image.

[0042] Specifically, after constructing the aforementioned indirect cooling tower anti-freezing monitoring system, a specific computer program can be configured for monitoring. To achieve better fault monitoring, in this embodiment, each triangular unit is used as the smallest unit for judgment, and corresponding system operating parameters are collected, including the circulation pump, whether the triangular unit is started, and the operating status of the corresponding power station. The load power can be directly read here. At the same time, the aforementioned dual-spectrum camera is controlled to collect dual-spectrum images at each location.

[0043] Then, by classifying the system operation scenarios, the current operation status of the triangular unit can be determined, such as whether the triangular unit is enabled, whether the triangular unit is in the early stage of operation, whether it is in the constant power range, whether the heat dissipation power has changed, and whether it is in the shutdown stage.

[0044] For different operating scenarios, the possible locations of freezing failures can be roughly estimated, and the corresponding bispectral images can be selected to identify the freezing failure points based on the corresponding recognition model.

[0045] In one embodiment, such as Figure 4 As shown, step S2 includes: Step S21: Extract the sector valve opening and closing status, circulating pump power, and power plant load power corresponding to the triangular unit from the system operating parameters; Step S22: Determine whether the current triangulation unit may be in operation based on the power plant load and the opening and closing status of the sector valves, so as to generate operation status prediction information. Step S23: Obtain the system operating scenario based on the estimated operating status information and the power matching of the circulating pump.

[0046] Specifically, to better determine the system's operating scenario, this embodiment first extracts the unit's circulating pump power and the power plant's load power from the system's operating parameters. Both sets of power parameters are power data sequences from a past period, reflecting the equipment's operating status over that time.

[0047] The circulating pump power directly indicates whether the circulating water in the pipeline is operating and whether the flow rate is slowing down or accelerating. The power plant load power is used to help determine whether the indirect cooling tower needs to operate at full power and whether the current triangular unit may actually need to be shut down.

[0048] By comparing the estimated operating status information with the actual circulating pump power, the current system operating scenario can be determined, for example: If the circulating pump power increases and the operating status prediction information indicates that the current triangular unit should be operating, then the flow rate of the circulating water will increase in the early stage of the operation of the indirect cooling tower. If the circulating pump power decreases and the operating status prediction information indicates that the current delta unit should be shut down, then the corresponding delta unit will stop rotating.

[0049] If the circulating pump power is constant and the estimated operating status information indicates that the current triangular unit should be operating, then it is in the constant power range.

[0050] If the power of the circulating pump is 0 and the estimated operating status indicates that the current triangulation unit should be running, then it is a fault condition.

[0051] In one embodiment, the system operation scenario includes the early stage of operation of the intercooling tower, and the corresponding bispectral image is the top image; like Figure 5 As shown, step S4 includes: Step A41: Segment the top image to obtain multiple tube regions; Step A42: Calculate the average pipe temperature for each tube bundle region based on the infrared spectral imaging results; Step A43: Based on the average temperature of all pipes, the low-temperature pipe bundle region is obtained by screening the pipe bundle region; Step A44: Locate the cold spot in the cryogenic tube bundle region as the output for freezing fault point.

[0052] Specifically, regarding the airlock phenomenon that may occur during the operation of the indirect cooling tower, the inventors conducted fluid analysis and concluded that the airlock mainly occurs when the power of the circulating pump increases, and the descending cooling water and the rising air bubbles cancel each other out, forming a vortex in the pipe. At this time, the actual pipe flow rate in this part is reduced, and there will be local cold spots.

[0053] To address this, the top image is first extracted from the bispectral image, and then a pre-trained U-net model is used to segment the tube regions one by one to determine multiple tube regions.

[0054] For each tube bundle region, the average temperature of each cooling pipe can be estimated by averaging the pixels based on the infrared spectral imaging results.

[0055] Subsequently, based on the average temperature of all pipes, the low-temperature pipe bundle region was selected, specifically including: The average pipe temperature is sorted to obtain the median pipe temperature, which is used as the representative temperature of the current cooling tube bundle plate. The deviation of the average pipe temperature of each group from the median pipe temperature is calculated. The pipe with the largest deviation is selected and it is determined whether the temperature difference between the average pipe temperature of the pipe and the average pipe temperature of the pipe is negative and greater than a preset threshold. If so, it is indicated as a low temperature pipe.

[0056] The low-temperature tube bundle region is output, and then the cold spot is further segmented to serve as the output of the freezing fault point.

[0057] In one embodiment, such as Figure 6 As shown, step A44 includes: Step A441: The top header extension region is segmented from the top image based on the cryogenic tube bundle region, and then stitched with the cryogenic tube bundle region to obtain the region to be identified; Step A442: Divide the area to be identified into multiple intervals at equal distances along the direction of liquid flow; Step A443: Calculate the average temperature of the interval to be identified, and then generate a temperature gradient sequence according to the direction of liquid flow; Step A444: Extract gradient abrupt change points from the temperature gradient sequence to determine the freezing fault point.

[0058] Specifically, in order to determine the location of the gas plug in the cryogenic tube bundle region, in this embodiment, we first return to the top image, segment the top manifold extension region from the top image by morphological dilation, and stitch it with the cryogenic tube bundle region to obtain the region to be identified, and monitor the movement of the bubble to the top of the manifold and discharge it from the automatic exhaust valve.

[0059] Subsequently, the area to be identified is divided into multiple regions at equal intervals along the direction of liquid flow. This process includes remapping the area to be identified with the extrinsic parameters of the dual-spectrum camera to obtain the spatial coordinates of each pixel, and then dividing the spatial coordinates at equal intervals to obtain the regions to be identified.

[0060] As cooling water descends through the pipes, its temperature gradually decreases, so ideally, its temperature gradient should exhibit an exponential decay. However, when airlock occurs, it will show obvious outliers or gradient discontinuities.

[0061] To address this, the average temperature of the interval to be identified can be calculated, and then a temperature gradient sequence can be generated according to the direction of liquid flow. Subsequently, the decay curve can be simulated based on the temperatures at both ends of the temperature gradient sequence and a standard temperature curve model. The gradient abrupt change point can be obtained by comparing the temperature gradient sequence with the gradient curve, thereby determining the freezing fault point.

[0062] In one embodiment, the system operation scenario includes the triangular unit stopping, and the corresponding bispectral image is the bottom image; like Figure 7 As shown, step S4 includes: Step B41: Acquire a series of bottom images prior to the monitoring time point, and segment the target area associated with the bottom water tank and the end of the pipe from each bottom image; Step B42: Divide the target area into temperature point windows, and stitch together the window image sequence according to the time order of the bottom image for each temperature point window. Step B43: Calculate the average temperature of each frame in the window image sequence and convert it to obtain the window temperature sequence; Step B44: Perform waveform matching on the window temperature sequence to obtain the cold spot as the output of the freezing fault point.

[0063] In step B44, the waveform matching result is that the window temperature sequence, after showing an abnormal peak in the matching sliding window of the preset time length, falls back to the freezing point.

[0064] Specifically, in the case of bottom freezing, the freezing phenomenon usually occurs when impurities in the water mix with residual water during the descent. In the case of a freezing zone descending, if freezing occurs inside the pipe, the freezing sequence is usually before the actual freezing point, because impurities slow down the water flow due to obstruction, causing localized supercooling, followed by actual freezing.

[0065] For this specific operating condition, a series of bottom images prior to the monitoring time point are first acquired and sorted according to the acquisition order. To reduce the workload of subsequent processing, target areas associated with the bottom water tank and the end of the pipe are segmented from each bottom image, thereby removing the upper areas that are unlikely to freeze.

[0066] Subsequently, the retained target area is divided into temperature point windows. This step involves dividing the area into multiple windows by pixel clustering, and then processing each temperature point window separately.

[0067] For each temperature point window, the window image sequence is first obtained by stitching together the bottom images in chronological order. Then, the average temperature of each frame of the window image sequence is calculated on the infrared band and converted to obtain the window temperature sequence.

[0068] Then, the window temperature sequence is matched according to the temperature waveform calibrated in the pre-experiment. If a matching result is found, it is highly likely that a freezing fault point has occurred in the area.

[0069] Those skilled in the art will understand that various aspects, or possible implementations of various aspects, of the present invention can be embodied as systems, methods, or computer program products. Therefore, various aspects, or possible implementations of various aspects, of the present invention can take the form of entirely hardware embodiments, entirely software embodiments (including firmware, resident software, etc.), or embodiments combining software and hardware aspects, all collectively referred to herein as "circuit," "module," or "system." Furthermore, various aspects, or possible implementations of various aspects, of the present invention can take the form of computer program products, which are computer instructions stored in memory.

[0070] The memory can be a computer-readable signal medium or a computer-readable storage medium. Computer-readable storage media include, but are not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or apparatuses, or any suitable combination thereof, such as random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, and portable read-only memory (CD-ROM).

[0071] A processor in a computer reads computer instructions stored in memory, enabling the processor to execute the functional actions specified in each step or combination of steps in a flowchart; and to generate means for implementing the functional actions specified in each block or combination of blocks in a flowchart.

[0072] It should be understood that a processor in a computer can be understood as one or more application-specific integrated circuits (ASICs), DSPs, programmable logic devices (PLDs), complex programmable logic devices (CPLDs), field-programmable gate arrays (FPGAs), general-purpose processors, controllers, microcontrollers (MCUs), microprocessors, or other electronic components used to execute the aforementioned computer instructions.

[0073] Computer instructions may be executed entirely on the user's local computer, partially on the user's local computer, as a separate software package, partially on the user's local computer and partially on a remote computer, or entirely on a remote computer or server. It should also be noted that in some alternative implementations, the functions indicated by the steps in the flowchart or the blocks in the block diagram may not occur in the order shown in the diagram. For example, depending on the functions involved, two consecutive steps or blocks may actually be executed approximately simultaneously, or these blocks may sometimes be executed in reverse order.

[0074] Of course, in practical applications, the various components of a computer system are coupled together through a bus system. The bus system is used to enable communication and connection between these components. In addition to the data bus, the bus system also includes a power bus, a control bus, and a status signal bus.

[0075] The above are merely preferred embodiments of the present invention and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should recognize that any equivalent substitutions and obvious changes made based on the description and illustrations of the present invention should be included within the protection scope of the present invention.

Claims

1. A freezing protection monitoring system for indirect cooling towers, characterized in that, Includes multiple sets of dual-spectrum monitoring devices and control systems; Each of the aforementioned dual-spectrum monitoring devices is installed on a triangular unit of the intercooling tower; The triangular unit consists of two sets of heat exchange tube bundles arranged at an angle. One end of each heat exchange tube bundle is abutted against the other end, and the bundles are fixed to the frame structure. The abutting end is used as the apex of the triangular unit. The dual-spectrum monitoring device includes a bottom monitoring device and a top monitoring device; The bottom monitoring device includes a pair of dual-spectrum cameras, which are respectively set at the two bottom corners of the triangular unit and take pictures of the bottom area of ​​the heat exchange tube bundle; The top monitoring device includes a pair of dual-spectrum cameras, which are respectively set at the two bottom corners of the triangular unit and take pictures of the top area of ​​the heat exchange tube bundle; The control system determines the freezing fault point based on the acquired images.

2. The antifreeze monitoring system for indirect cooling towers according to claim 1, characterized in that, The bottom monitoring device is installed at a height of 2.1m above the base plate of the triangular unit, and the field of view of the bottom monitoring device is set to fit the adjacent heat exchange tube bundle and the frame structure at the bottom edge.

3. The anti-freezing monitoring system for indirect cooling towers according to claim 1, characterized in that, The installation height of the top monitoring device is 2.1m below the top sealing plate of the triangular unit, and the field of view of the top monitoring device is set to fit the adjacent heat exchange tube bundle and the frame structure at the bottom.

4. A monitoring method, characterized in that, Applicable to the antifreeze monitoring system for indirect cooling towers as described in any one of claims 1-3; The monitoring method includes: Step S1: Collect system operating parameters for each triangular unit to be monitored and capture bispectral images; The dual-spectral image includes a top image corresponding to the top region of the triangular unit and a bottom image corresponding to the bottom region of the triangular unit; Step S2: Match the system operating parameters to determine the system operating scenario; Step S3: Obtain the bispectral image at the corresponding location according to the system operation scenario; Step S4: Identify the frozen fault points from the bispectral image.

5. The monitoring method according to claim 4, characterized in that, Step S2 includes: Step S21: Extract the sector valve opening / closing status, circulating pump power, and power plant load power corresponding to the triangular unit from the system operating parameters; Step S22: Determine whether the current triangular unit may be in operation based on the power load of the power plant and the opening and closing status of the sector valves corresponding to the triangular unit, so as to generate operation status prediction information. Step S23: Obtain the system operation scenario based on the estimated operating status information and the power matching of the circulating pump.

6. The monitoring method according to claim 4, characterized in that, The system operation scenario includes the early stage of operation of the intercooling tower, and the corresponding dual-spectral image is the top image; Step S4 includes: Step A41: Segmenting multiple tube regions from the top image; Step A42: Calculate the average pipe temperature for each of the tube bundle regions based on the infrared spectral imaging results; Step A43: Based on the average temperature of all the pipes, the tube bundle region is screened to obtain the low-temperature tube bundle region; Step A44: Locate the cold spot in the cryogenic tube bundle region as the output of the freezing fault point.

7. The monitoring method according to claim 6, characterized in that, Step A44 includes: Step A441: Based on the cryogenic tube bundle region, the top manifold extension region is segmented from the top image and then stitched together with the cryogenic tube bundle region to obtain the region to be identified; Step A442: Divide the area to be identified into multiple intervals at equal distances along the direction of liquid flow; Step A443: Calculate the average temperature for the interval to be identified, and then generate a temperature gradient sequence according to the direction of liquid flow; Step A444: Extract gradient abrupt change points from the temperature gradient sequence to determine the freezing fault point.

8. The monitoring method according to claim 4, characterized in that, The system operation scenario includes the triangular unit stopping, and the corresponding bispectral image is the bottom image; Step S4 includes: Step B41: Acquire a series of bottom images prior to the monitoring time point, and segment the target area associated with the bottom water tank and the end of the pipe from each bottom image; Step B42: Divide the target area into temperature point windows, and stitch together the window image sequence according to the time sequence of the bottom image for each of the divided temperature point windows; Step B43: Calculate the average temperature of each frame of the window image sequence and convert it to obtain the window temperature sequence; Step B44: Perform waveform matching on the window temperature sequence to obtain the cold spot as the output of the freezing fault point.

9. The monitoring method according to claim 8, characterized in that, In step B44, the result of the waveform matching is that the window temperature sequence moves to the freezing point after an abnormal trough appears in the matching sliding window of a preset time length.

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