Heat exchange device pitting detection method and heat exchange device pitting detection equipment

Abstract

The present application relates to a heat exchanger device pitting corrosion detection method and heat exchanger device pitting corrosion detection equipment, wherein the heat exchanger device pitting corrosion detection method comprises: obtaining a target infrared thermal image of the heat exchanger device during a salt spray test on the heat exchanger device; performing target area detection on the target infrared thermal image, and when the target area exists in the target infrared thermal image, determining the temperature difference between the target area and the surrounding area and the shape of the target area, wherein the target area includes a bright area and / or a dark area; and analyzing and obtaining the target pitting corrosion result of the heat exchanger device based on the temperature difference and the shape of the target area. Through this application, in-situ monitoring of pitting corrosion and pitting corrosion failure of automotive heat exchanger devices is achieved without destroying the heat exchanger device.

Description

Technical Field

[0001] The present application relates to the field of heat exchanger detection, and in particular to a heat exchanger device pitting detection method and a heat exchanger device pitting detection device. Background Art

[0002] Automotive heat exchangers typically use heat transfer fluids (such as air, exhaust gas, coolant, engine oil, and lubricants) to cool the engine, fuel, oil, and lubricants, as well as to control the temperature of the engine compartment and cab. However, during use, the coolant's impact on the heat exchanger can cause pitting corrosion within the device's piping, or even leaks that can lead to device failure. This can severely impact driving safety, especially during driving. Currently, pitting corrosion in heat exchangers is primarily detected by cutting and cross-sectioning heat exchanger samples, but this method is damaging to the sample.

[0003] There is currently no effective solution to the problem in related technologies that pitting corrosion and pitting failure of automotive heat exchange components cannot be monitored in situ. Summary of the Invention

[0004] In this embodiment, a heat exchange device pitting corrosion detection method and a heat exchange device pitting corrosion detection device are provided to solve the problem in the related art that pitting corrosion and pitting corrosion failure of automobile heat exchange devices cannot be monitored in situ.

[0005] In a first aspect, this embodiment provides a method for detecting pitting corrosion of a heat exchanger, including:

[0006] During the salt spray test of the heat exchange device, obtaining a target infrared thermal image of the heat exchange device;

[0007] Performing target area detection on the target infrared thermal image, and when the target area exists in the target infrared thermal image, determining the temperature difference between the target area and the surrounding area and the shape of the target area, wherein the target area includes a bright area and / or a dark area;

[0008] A target pitting corrosion result of the heat exchange device is obtained by analysis based on the temperature difference and the shape of the target area.

[0009] In some embodiments, analyzing and obtaining a target pitting corrosion result of the heat exchange device based on the temperature difference and the shape of the target area includes:

[0010] When the target area includes only bright areas, analyzing the temperature difference between the bright areas in the target infrared thermal image and the bright areas of the surrounding intact areas and the regional shape of the bright areas in the target infrared thermal image to obtain a first pitting corrosion result of the heat exchange component; and using the first pitting corrosion result as the target pitting corrosion result;

[0011] When the target area includes only a dark area, analyzing the temperature difference between the dark area and the surrounding intact dark area in the target infrared thermal image and the regional shape of the dark area in the target infrared thermal image to obtain a second pitting corrosion result of the heat exchange component; and using the second pitting corrosion result as the target pitting corrosion result;

[0012] When the target area includes a bright area and a dark area, the target pitting corrosion result is obtained by combining the first pitting corrosion result and the second pitting corrosion result.

[0013] In some embodiments, analyzing the temperature difference between the bright area in the target infrared thermal image and the surrounding intact area and the regional shape of the bright area in the target infrared thermal image to obtain the first pitting corrosion result of the heat exchange device includes:

[0014] When the temperature difference of the bright area is within a preset first temperature difference range, if the shape of the bright area is a small dot, it is determined that the tube wall of the heat exchange device is thinning and pitting cracking of the coating of the heat exchange device occurs;

[0015] When the temperature difference of the bright area is within a preset second temperature difference range, if the shape of the bright area is a concentric ring or an elliptical ring, it is determined that the tube wall of the heat exchange device is thinning and the pitting corrosion of the heat exchange device is expanding in the circumferential direction;

[0016] When the temperature difference of the bright area is within a preset second temperature difference range, if the shape of the bright area is a small dot or irregular shape, it is determined that the tube wall of the heat exchange device is thinning and the pitting corrosion of the heat exchange device is extending along the wall;

[0017] Wherein, the first temperature difference range is smaller than the second temperature difference range.

[0018] In some embodiments, analyzing the temperature difference between the dark area in the target infrared thermal image and the surrounding intact dark area and the shape of the dark area in the target infrared thermal image to obtain the second pitting corrosion result of the heat exchange device includes:

[0019] When the temperature difference of the dark area is within a preset third temperature difference range, and if the shape of the dark area is irregular, it is determined that the heat exchange device has an impurity quality defect;

[0020] When the temperature difference of the dark area is within a preset fourth temperature difference range, if the shape of the dark area is a circle or an ellipse, it is determined that bubbling occurs in the coating of the heat exchange device and bubbles occur in the internal pipe of the heat exchange device;

[0021] When the temperature difference of the dark area is within a preset fourth temperature difference range, if the shape of the dark area is a small dot or an irregular shape, it is determined that the heat exchange device has pitting failure;

[0022] Wherein, the third temperature difference range is smaller than the fourth temperature difference range.

[0023] In some embodiments, the process of performing a salt spray test on the heat exchange device further includes:

[0024] Performing real-time pressure detection on the heat exchange device in a sealed state at the pipeline outlet to obtain a real-time pressure value;

[0025] Calculating the pressure difference between the real-time pressure value and the initial pressure value; the initial pressure value is obtained by the initial detection when the heat exchange device is sealed;

[0026] When the pressure difference reaches a preset pressure difference threshold, it is determined that pitting failure occurs in the heat exchange component, and a pitting failure warning message is issued.

[0027] In some of the embodiments, the leakage amount of the heat exchange device causing pitting failure is determined based on the pressure difference;

[0028] The service life of the heat exchange device is determined according to the leakage amount.

[0029] In some embodiments, the process of performing a salt spray test on the heat exchange device further includes:

[0030] Acquire weak magnetic field monitoring data of the area where the heat exchange device is located;

[0031] Drawing a weak magnetic field monitoring data curve graph according to the weak magnetic field monitoring data;

[0032] The locations of the peaks and troughs in the weak magnetic monitoring data curve are determined as locations where pitting corrosion occurs in the heat exchange device.

[0033] In some embodiments, the process of performing a salt spray test on the heat exchange device further includes:

[0034] A constant current is applied to the heat exchange device based on a constant current meter, or a constant voltage is applied to the heat exchange device based on a constant potential meter, so as to accelerate the corrosion rate of the heat exchange device during the salt spray test.

[0035] In some embodiments, the process of performing a salt spray test on the heat exchange device further includes:

[0036] Determining whether pitting corrosion occurs in the heat exchange device based on the ion concentration of the heat exchange device detected by an in-situ concentration monitoring device connected to the interior of the heat exchange device; or

[0037] Whether pitting corrosion occurs in the heat exchange device is determined based on the pH value inside the heat exchange device detected by a pH meter connected to the inside of the heat exchange device.

[0038] In a second aspect, this embodiment provides a heat exchanger device pitting corrosion detection device, which applies the heat exchanger device pitting corrosion detection method described in the first aspect. The heat exchanger device pitting corrosion detection device includes: an in-situ infrared thermal imager, a pressure monitoring device, a weak magnetic detector, a constant current meter, a constant potentiostat, an in-situ concentration monitoring device, a pH meter, and an analytical device; wherein:

[0039] The in-situ infrared thermal imager is arranged on the outside of the heat exchange device, and is used to collect a target infrared thermal image of the heat exchange device, and transmit the target infrared thermal image to the analysis device, so that the analysis device determines the pitting corrosion condition of the heat exchange device according to the target infrared thermal image;

[0040] The pressure monitoring device is provided at the inlet of the heat exchange device, and is used to detect the real-time pressure value of the heat exchange device and transmit the real-time pressure value to the analysis device, so that the analysis device can determine whether the heat exchange device has pitting failure according to the real-time pressure value;

[0041] The weak magnetic detector is arranged around the heat exchange device, and is used to scan the area where the heat exchange device is located to obtain weak magnetic monitoring data; and transmit the weak magnetic monitoring data to the analysis device, so that the analysis device can analyze the weak magnetic monitoring data to obtain the location where the pitting corrosion of the heat exchange device occurs;

[0042] The constant current meter and the constant potentiostat are connected to the heat exchange device and are used to apply a constant current or a constant voltage to the heat exchange device to accelerate the corrosion rate of the heat exchange device during the salt spray test;

[0043] The in-situ concentration monitoring device is arranged inside the heat exchange device, and is used to detect the ion concentration of the heat exchange device and transmit the ion concentration to the analysis device, so that the analysis device can determine whether the heat exchange device has pitting corrosion according to the ion concentration;

[0044] The pH meter is arranged inside the heat exchange device, and is used to detect the pH value inside the heat exchange device and transmit the pH value to the analysis device, so that the analysis device can judge whether pitting corrosion occurs in the heat exchange device based on the pH value.

[0045] Compared with the related art, the heat exchange device pitting corrosion detection method provided in this embodiment obtains a target infrared thermal image of the heat exchange device during a salt spray test on the heat exchange device; performs target area detection on the target infrared thermal image, and when the target area exists in the target infrared thermal image, determines the temperature difference between the target area and the surrounding area and the shape of the target area, wherein the target area includes a bright area and / or a dark area; and analyzes the target pitting corrosion result of the heat exchange device based on the temperature difference and the shape of the target area, thereby realizing in-situ monitoring of pitting corrosion and pitting corrosion failure of automotive heat exchange devices without destroying the heat exchange device.

[0046] The details of one or more embodiments of the present application are set forth in the following drawings and description to make other features, objects, and advantages of the present application more readily apparent. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0048] Figure 1 This is a hardware structure block diagram of a terminal of the heat exchange device pitting detection method of this embodiment.

[0049] Figure 2 4 is a flow chart of the heat exchange device pitting detection method of this embodiment.

[0050] Figure 3a This is an example diagram of the shape of an area where the temperature difference of the bright area of the heat exchange device pitting detection method of this embodiment is within a preset first temperature difference range.

[0051] Figure 3b This is an example diagram of the shape of an area where the temperature difference of the bright area of the heat exchange device pitting detection method of this embodiment is within the preset second temperature difference range.

[0052] Figure 3c This is another example diagram of the shape of an area where the temperature difference of the bright area of the heat exchange device pitting detection method of this embodiment is within a preset second temperature difference range.

[0053] Figure 4a This is an example diagram of the shape of an area where the temperature difference of the dark area in the heat exchange device pitting detection method of this embodiment is within the preset third temperature difference range.

[0054] Figure 4b This is an example diagram of the shape of an area where the temperature difference of the dark area in the heat exchange device pitting detection method of this embodiment is within the preset fourth temperature difference range.

[0055] Figure 4c This is another example diagram of the shape of an area where the temperature difference of the dark area of the heat exchange device pitting detection method of this embodiment is within the preset fourth temperature difference range.

[0056] Figure 5 This is a diagram of weak magnetic monitoring data in the heat exchange device pitting detection method of this embodiment.

[0057] Figure 6 This is a flow chart of another method for detecting pitting corrosion of a heat exchange device according to this embodiment.

[0058] Figure 7 4 is a structural block diagram of the heat exchange device pitting detection device of this embodiment. DETAILED DESCRIPTION

[0059] In order to more clearly understand the purpose, technical solutions and advantages of the present application, the present application is described and illustrated below in conjunction with the accompanying drawings and embodiments.

[0060] Unless otherwise defined, technical or scientific terms used in this application shall have the ordinary meanings as understood by persons of ordinary skill in the art to which this application belongs. The terms "a," "an," "the," "these," and similar expressions in this application do not denote limitations on quantity and may be singular or plural. The terms "comprise," "include," "have," and any variations thereof, as used in this application, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or device comprising a series of steps or modules (units) is not limited to the listed steps or modules (units) but may include unlisted steps or modules (units) or other steps or modules (units) inherent to the process, method, product, or device. The terms "connected," "connected," "coupled," and similar expressions used in this application are not limited to physical or mechanical connections but may include electrical connections, whether direct or indirect. As used in this application, "plurality" means two or more. "And / or" describes an association between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists alone; A and B exist simultaneously; or B exists alone. Generally, the character " / " indicates that the objects in the preceding and following relationship are in an "or" relationship. The terms "first", "second", "third", etc. involved in this application are only used to distinguish similar objects and do not represent a specific ordering of the objects.

[0061] The method embodiment provided in this embodiment can be executed in a terminal, a computer or a similar computing device. For example, running on a terminal, Figure 1 FIG. 1 is a block diagram of the hardware structure of the terminal of the heat exchange device pitting detection method of this embodiment. Figure 1 As shown, the terminal may include one or more ( Figure 1 The processor 102 (only one is shown) and a memory 104 for storing data, wherein the processor 102 may include but is not limited to a processing device such as a microprocessor MCU or a programmable logic device FPGA. The terminal may also include a transmission device 106 for communication functions and an input / output device 108. It will be understood by those skilled in the art that Figure 1 The structure shown is only for illustration and does not limit the structure of the above terminal. Figure 1 More or fewer components than shown, or with Figure 1 Different configurations shown.

[0062] The memory 104 can be used to store computer programs, for example, software programs and modules of application software, such as the computer program corresponding to the heat exchange device pitting detection method in this embodiment. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, that is, implementing the above-mentioned method. The memory 104 may include a high-speed random access memory and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some examples, the memory 104 may further include a memory remotely located relative to the processor 102, and these remote memories may be connected to the terminal via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0063] Transmission device 106 is used to receive or transmit data via a network. This network may include a wireless network provided by the terminal's communications provider. In one embodiment, transmission device 106 includes a network interface controller (NIC), which can be connected to other network devices via a base station to enable communication with the Internet. In another embodiment, transmission device 106 may be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0064] In this embodiment, a method for detecting pitting corrosion of a heat exchange device is provided. Figure 2 FIG. 1 is a flow chart of the heat exchange device pitting detection method of this embodiment. Figure 2 As shown, the process includes the following steps:

[0065] Step S201 : acquiring a target infrared thermal image of the heat exchange component during a salt spray test on the heat exchange component.

[0066] Specifically, pitting corrosion is a form of localized corrosion that usually forms pits on the surface of the material. These pits may be blocked by corrosion products and difficult to detect in time, leading to sudden accidents. Pitting failure refers to the phenomenon that when a metal material is in a corrosive medium, the protective film or passivation film in a local area is destroyed, forming small pore-shaped corrosion defects, which in turn leads to a decrease in material performance or even structural failure. For the sake of convenience, this embodiment uses an automotive heat exchanger as an example for explanation. It is understandable that other heat exchangers are also applicable to the pitting corrosion detection method of this embodiment, and this embodiment does not impose specific restrictions on this. Currently, in the existing related technologies, after the heat exchanger is subjected to a salt spray test, the pitting corrosion of the heat exchanger after the test is mainly observed by cutting the heat exchanger sample and making a cross-section. This often damages the sample, and the need to cut the sample also consumes a lot of equipment and time, and the detection efficiency is relatively low. To this end, in this embodiment, an in-situ infrared thermal imager is introduced to inspect the heat exchanger during the test. Among them, when the heat exchange device corrodes, the corrosion reaction will generate a certain amount of heat, which will cause the temperature of the corroded area to be higher than the temperature of the surrounding normal parts. This embodiment arranges an in-situ infrared thermal imager around the heat exchange device to detect the invisible infrared heat emitted by the heat exchange device, and converts the detected invisible infrared heat emitted by the heat exchange device into a visible target infrared thermal image, thereby obtaining the temperature distribution of the heat exchange device.

[0067] Illustratively, in this embodiment, the wavelength of the acquisition module of the infrared thermal imager can be set to 2μm-6μm, the resolution can be set to higher than 640×512, the temperature resolution can be set to lower than 0.1°C, the acquisition area of the acquisition module can include at least 1 / 4 of the surface area of the heat exchange device, and the number of acquisition modules of the infrared thermal imager can be increased according to the size of the surface area to ensure that the acquisition range of the infrared thermal imager can cover the entire surface of the heat exchange device. The acquisition module collects the infrared thermal image of the entire surface of the heat exchange device at least once within 1 minute, and transmits the collected target infrared thermal image to the display of the analysis equipment outside the salt spray test chamber.

[0068] Step S202 : performing target area detection on the target infrared thermal image. When the target area exists in the target infrared thermal image, determining the temperature difference between the target area and the surrounding area and the shape of the target area, wherein the target area includes a bright area and / or a dark area.

[0069] After acquiring a target infrared thermal image of a heat exchanger, if pitting corrosion is present on the surface of the heat exchanger, different bright and dark areas will appear in the target infrared image due to the different heat conduction characteristics of the pitted area compared to normal areas. If pitting corrosion is not present, the surface temperature distribution of the heat exchanger is relatively uniform, and the target infrared image will appear with a relatively uniform color. If pitting corrosion is present, bright or dark areas, or both, will appear in the target infrared image. These areas are due to local temperature changes caused by pitting corrosion. Therefore, after acquiring the target infrared image, further target area detection is required to determine whether there are abnormal bright or dark areas. First, image processing techniques (such as threshold segmentation and edge detection) are used to determine whether bright or dark areas exist in the target infrared image. The presence of these areas indicates the presence of pitting corrosion. Once the target area is detected, the temperature difference between this area and the surrounding normal areas is further analyzed. Areas without pitting corrosion or pitting failure are considered normal areas and appear with a uniform color in the infrared image. The magnitude of the temperature difference reflects the severity of the pitting corrosion. A large temperature difference indicates deeper pitting corrosion and more severe corrosion. A small temperature difference indicates shallow pitting and relatively mild corrosion. Furthermore, the shape of the target area should be examined based on the temperature difference. Different target area shapes will result in different pitting conditions. The target area may be in the form of small dots, concentric circles, or other irregular shapes.

[0070] Step S203 : Analyze and obtain target pitting results of the heat exchange component based on the temperature difference and the shape of the target area.

[0071] Specifically, pitting analysis is performed based on the brightness, temperature difference, and shape of the target area. Different brightness, temperature differences, and shapes of the target area correspond to different pitting results.

[0072] In some embodiments, analyzing and obtaining a target pitting corrosion result of a heat exchange device based on the temperature difference and the shape of the target area includes:

[0073] When the target area only includes bright areas, the temperature difference between the bright areas in the target infrared thermal image and the surrounding intact areas and the regional shape of the bright areas in the target infrared thermal image are analyzed to obtain the first pitting corrosion result of the heat exchange device; the first pitting corrosion result is used as the target pitting corrosion result.

[0074] Specifically, the bright area of the target infrared thermal image is the area where pitting corrosion occurs. If a bright area exists in the infrared thermal image, it indicates that pitting corrosion has occurred in the target area. Based on the judgment of the bright area, the temperature difference between the bright area and the surrounding intact area is calculated. The pitting corrosion results are analyzed in combination with the shape of the bright area. Different temperature differences and different bright area shapes correspond to different pitting corrosion results. For example, when a small point-shaped bright area appears when the temperature difference is small, it can be determined that pitting corrosion has occurred in the heat exchange device, and it can be determined that it is caused by cracking of the heat exchange device's coating. The pitting corrosion result is recorded as the first pitting corrosion result. If the target infrared thermal image only contains this bright area, the pitting corrosion result obtained by analyzing the bright area is determined as the target pitting corrosion result.

[0075] When the target area only includes the dark area, the temperature difference between the dark area in the target infrared thermal image and the dark area of the surrounding intact area and the regional shape of the dark area in the target infrared thermal image are analyzed to obtain the second pitting corrosion result of the heat exchange device; the second pitting corrosion result is used as the target pitting corrosion result.

[0076] Specifically, the dark area of the target infrared thermal image is the area where pitting failure may occur. Similarly, if there is a dark area in the infrared thermal image, it indicates that pitting failure has occurred in the target area. Based on the judgment that it is a dark area, the temperature difference between the dark area and the surrounding intact area is calculated, and the pitting results are analyzed in combination with the shape of the dark area. Different temperature differences and different dark area shapes correspond to different pitting results. For example, when a small point-shaped dark area appears when the temperature difference is large, it can be determined that the heat exchange device has pitting failure, and it can be determined that the heat exchange device has perforated. Record the pitting failure result as the second pitting result. If there is only this dark area in the target infrared thermal image, the pitting result obtained by analyzing the dark area will be determined as the target pitting result.

[0077] When the target area includes a bright area and a dark area, the target pitting result is obtained by combining the first pitting result and the second pitting result.

[0078] Specifically, if the target area of the detected infrared thermal image includes both bright areas and dark areas, the bright areas and dark areas are detected and analyzed separately according to the above detection method, and the first pitting corrosion result and the second pitting corrosion result obtained by detection are combined to obtain the target pitting corrosion result.

[0079] Through the above steps S201 to S203, during the salt spray test of the heat exchanger, a target infrared thermal image of the heat exchanger is obtained; a target area detection is performed on the target infrared thermal image, and when a target area exists in the target infrared thermal image, the temperature difference between the target area and the surrounding area and the shape of the target area are determined, wherein the target area includes a bright area and / or a dark area; and based on the temperature difference and the shape of the target area, a target pitting result of the heat exchanger is analyzed and obtained. Compared with the prior art method of observing the pitting corrosion of the heat exchanger by cutting a sample of the heat exchanger and making a cross-section, the present embodiment obtains the pitting corrosion result and the cause of the pitting corrosion by collecting the target infrared thermal image of the heat exchanger in the salt spray test, and analyzing and judging the temperature difference and shape of the target area in the target infrared thermal image, thereby avoiding damage to the heat exchanger and achieving in-situ detection of pitting corrosion and pitting corrosion failure of automotive heat exchangers.

[0080] In some embodiments, analyzing the temperature difference between a bright area in a target infrared thermal image and a surrounding intact area and the shape of the bright area in the target infrared thermal image to obtain a first pitting corrosion result of the heat exchange component includes:

[0081] When the temperature difference of the bright area is within the preset first temperature difference range, if the shape of the bright area is a small dot, it is determined that the tube wall of the heat exchange device is thinning and the coating of the heat exchange device has pitting cracking;

[0082] When the temperature difference of the bright area is within the preset second temperature difference range, if the shape of the bright area is a concentric ring or an elliptical ring, it is determined that the tube wall of the heat exchange device is thinning and the pitting corrosion of the heat exchange device is expanding along the circumferential direction;

[0083] When the temperature difference of the bright area is within the preset second temperature difference range, if the shape of the bright area is a small dot or irregular shape, it is determined that the tube wall of the heat exchange device is thinning and the pitting corrosion of the heat exchange device is extending along the wall;

[0084] The first temperature difference range is smaller than the second temperature difference range.

[0085] Specifically, in the above step S203, when the target area is a bright area, different pitting corrosion results can be obtained according to different temperature differences in the bright area in combination with different area shapes. Figure 3a This is an example diagram of the shape of the area where the temperature difference of the bright area of the heat exchange device pitting detection method of this embodiment is within the preset first temperature difference range. Figure 3a As shown, when the temperature difference of the bright area is within the preset first temperature difference range of 0°C-1°C, and the shape of the bright area is a small dot, it can be analyzed that pitting corrosion occurs at this location of the heat exchange device, and the tube wall of the heat exchange device at this location is thinned. It can be determined that the pitting corrosion is caused by cracking of the coating of the heat exchange device at this location. Figure 3bThis is an example diagram of the shape of the area where the temperature difference of the bright area of the heat exchange device pitting detection method of this embodiment is within the preset second temperature difference range. Figure 3b As shown, when the temperature difference of the bright area is greater than 1°C in the preset second temperature difference range, and the shape of the bright area is a concentric ring or an elliptical ring, it can be analyzed that pitting corrosion occurs at this location of the heat exchange device, and the tube wall of the heat exchange device at this location is thinned. It can also be determined that the pitting corrosion of the heat exchange device at this location extends along the circumferential direction, that is, the trend of the pitting corrosion is to expand horizontally outward toward the plane where the wall of the heat exchange device is located, and the pitting corrosion area tends to expand. Figure 3c This is another example of the shape of the region where the temperature difference of the bright area of the heat exchange device pitting detection method of this embodiment is within the preset second temperature difference range. Figure 3c As shown, when the temperature difference of the bright area is greater than 1°C in the preset second temperature difference range, and the shape of the bright area is a small dot or irregular shape, it can be analyzed that pitting corrosion occurs at this location of the heat exchange device, and the tube wall of the heat exchange device at this location is thinned. It can also be determined that the pitting corrosion of the heat exchange device at this location extends along the wall, that is, the trend of the pitting corrosion is to expand from the inside to the outside perpendicular to the plane where the wall of the heat exchange device is located, and the pitting corrosion area may have a tendency to perforate, thereby leading to pitting corrosion failure.

[0086] In another embodiment, analyzing the temperature difference between the dark area in the target infrared thermal image and the surrounding intact dark area and the regional shape of the dark area in the target infrared thermal image to obtain a second pitting corrosion result of the heat exchange component includes:

[0087] When the temperature difference of the dark area is within a preset third temperature difference range, if the shape of the dark area is irregular, it is determined that the heat exchange device has impurity quality defects;

[0088] When the temperature difference of the dark area is within a preset fourth temperature difference range, if the shape of the dark area is a circle or an ellipse, it is determined that bubbling occurs in the coating of the heat exchange device and bubbles appear in the internal pipes of the heat exchange device;

[0089] When the temperature difference of the dark area is within the preset fourth temperature difference range, if the shape of the dark area is a small dot or an irregular shape, it is determined that pitting failure occurs in the heat exchange device;

[0090] The third temperature difference range is smaller than the fourth temperature difference range.

[0091] Specifically, in the above step S203, when the target area is a dark area, different pitting corrosion results can be obtained according to different temperature differences in the dark area combined with different area shapes. Figure 4a : is an example diagram of the shape of the area where the temperature difference of the dark area of the heat exchange device pitting detection method of this embodiment is within the preset third temperature difference range. Figure 4aWhen the temperature difference of the dark area is within the preset third temperature difference range of 0°C-1°C, and the shape of the dark area is irregular, it can be analyzed that the heat exchange device has quality defects such as impurities at this location, and the dark area may be caused by impurities in the wall of the heat exchange device. Figure 4b : is an example diagram of the shape of the area where the temperature difference of the dark area of the heat exchange device pitting detection method of this embodiment is within the preset fourth temperature difference range. Figure 4b As shown, when the temperature difference of the dark area is greater than 1°C in the preset fourth temperature difference range, and the shape of the dark area is circular or elliptical, it can be analyzed that bubbles appear in the coating of the heat exchange device at that location, or large bubbles appear in the internal pipeline of the heat exchange device, and perforation may occur at that location, resulting in pitting failure. Figure 4c This is another example of the shape of the region where the dark area temperature difference of the heat exchange device pitting detection method of this embodiment is within the preset fourth temperature difference range. Figure 4c As shown, when the temperature difference of the dark area is greater than 1°C in the preset fourth temperature difference range, and the shape of the dark area is a small dot or irregular shape, it can be analyzed that the heat exchange device has a perforation phenomenon at this location, and pitting failure occurs at this location.

[0092] Therefore, this embodiment collects the target infrared thermal image of the heat exchanger in the salt spray test, and combines the brightness and darkness of the target area and the regional shape presented under different temperature differences to realize in-situ monitoring of the pitting condition, pitting cause and pitting trend of the heat exchanger during the salt spray test, thereby avoiding damage to the heat exchanger and realizing in-situ detection of pitting and pitting failure of automobile heat exchangers.

[0093] In some embodiments, the process of performing a salt spray test on a heat exchange device further includes:

[0094] Perform real-time pressure detection on the heat exchange device in the sealed state of the pipeline outlet to obtain the real-time pressure value; calculate the pressure difference between the real-time pressure value and the initial pressure value; the initial pressure value is obtained by the first detection when the heat exchange device is sealed; when the pressure difference reaches the preset pressure difference threshold, it is judged that the heat exchange device has pitting failure and a pitting failure warning information is issued.

[0095] Specifically, in addition to the above-mentioned pitting corrosion detection of the heat exchange device by the in-situ infrared thermal imager, in this embodiment, a pressure monitoring device is also introduced to perform pressure detection on the heat exchange device, and whether the heat exchange device has pitting corrosion failure is determined by the change in pressure value.

[0096] First, dry the heat exchanger in a forced-air drying oven at 100-180°C for 1-2 hours to remove any moisture on and inside the heat exchanger. This prevents moisture from interfering with test results during subsequent inflation or salt spray testing, such as affecting gas pressure stability or altering the corrosive environment of the salt spray test. After drying, cool the heat exchanger under a protective atmosphere, preferably nitrogen. Nitrogen is chemically stable and does not react easily with other substances, preventing oxidation of the heat exchanger during the cooling process. Seal the heat exchanger's piping outlet, preferably by welding. Welding provides a good seal, preventing gas leakage from the outlet during subsequent inflation and testing. While sealing the piping inlet, connect an internal spring-loaded airtight core. This airtight core has an internal spring structure that facilitates inflation or water handling and also allows connection to a pressure sensor. Fill the heat exchanger through the airtight core with 1.8-8 bar (1 bar equals 100,000 Pascals (Pa)) of gas or water. Compressed air or nitrogen is preferred. Compressed air is readily available and relatively inexpensive. Nitrogen, due to its larger molecules, is less likely to penetrate the tiny pores of materials, thus better maintaining pressure stability. A pressure monitoring device is connected to the airtight core to monitor pressure changes within the heat exchanger in real time. The pressure monitoring device can be a pressure sensor, and the specific selection can be based on actual conditions and is not specifically limited in this embodiment.

[0097] The heat exchanger, equipped with the pressure sensor, was then placed in a circulating salt spray chamber, with the heat exchanger at a distance of more than 20 centimeters in both length and width from the nozzle and more than 10 centimeters from the edges of the chamber. This protected the heat exchanger from direct impact from the salt spray from the nozzle and ensured it was within the chamber's effective corrosion environment.

[0098] During the salt spray test, the initial pressure value when the heat exchange device is sealed is first collected. Then, pressure data is collected every 1 second to obtain the real-time pressure value. The real-time pressure value is transmitted to the display of the analysis equipment outside the salt spray test chamber via Bluetooth and recorded as a curve.

[0099] Calculate the pressure difference between the real-time pressure value and the initial pressure value ( ), and set the pressure difference ( When the pressure difference reaches a preset 5%-10% pressure difference, a pitting failure alarm is issued, alerting the tester that pitting failure has occurred in the heat exchanger, allowing the tester to record test data promptly. When the pressure difference reaches this preset pressure difference threshold, it indicates that the heat exchanger has leaked due to salt spray corrosion, indicating pitting failure. The specific pressure difference threshold can be set based on actual conditions and is not specifically limited in this embodiment. The pressure monitoring device can provide timely warning of pitting failure without damaging the heat exchanger sample.

[0100] In another embodiment, the leakage amount of the heat exchange device that causes pitting failure is determined based on the pressure difference; and the service life of the heat exchange device is determined based on the leakage amount.

[0101] Specifically, in the above embodiment, after the detection and early warning of pitting failure are realized by setting a pressure monitoring device, the pressure difference ( ) can also calculate the leakage of heat exchange components due to pitting failure. The specific calculation formula is as follows:

[0102] ;

[0103] Where a is the leakage coefficient, which is 0.0006; v is the volume of the heat exchanger and the test circuit; for The pressure difference generated by the pressure sensing device over time.

[0104] During salt spray corrosion testing, the time it takes for leakage to exceed 5% of the heat exchanger's volume is recorded and used as a reference for the heat exchanger's salt spray corrosion lifespan. When leakage reaches 5% of the volume, the device's sealing performance has significantly degraded and may no longer meet actual operating requirements. This point in time can be used as a sign of heat exchanger failure. This method allows for a quantitative assessment of heat exchanger performance in different corrosive environments, providing an important basis for product design optimization and service life prediction.

[0105] In some embodiments, during the salt spray test of the heat exchange device, the process also includes: obtaining weak magnetic monitoring data of the area where the heat exchange device is located; drawing a weak magnetic monitoring data curve chart based on the weak magnetic monitoring data; and determining the locations of the peaks and troughs in the weak magnetic monitoring data curve chart as the locations where pitting corrosion occurs in the heat exchange device.

[0106] Specifically, based on the above-mentioned pitting corrosion detection of heat exchange devices by in-situ infrared thermal imager or pitting corrosion and pitting corrosion failure detection of heat exchange devices by in-situ infrared thermal imager combined with pressure monitoring device, this embodiment also introduces a weak magnetic detector to further detect the pitting corrosion of heat exchange devices.

[0107] During the salt spray test, a weak magnetic detector is used to collect the magnetic signals of the area where the heat exchange device is located in real time. Weak magnetic detection technology uses the change of magnetic signals to reflect the corrosion of the material. When pitting occurs on the surface of the heat exchange device, its magnetic signal will change significantly, and these changes can be recorded by the detector. The weak magnetic detector monitors the changes in magnetic induction intensity through a weak magnetic probe, wherein the range of the weak magnetic probe is ≥|250000|nT, the resolution is ≤0.1nT, the sampling frequency is ≥12.5Hz, the weak magnetic probe is perpendicular to the heat exchange device, and a fixed horizontal slide rail is set under the weak magnetic probe. The weak magnetic probe maintains uniform movement on the slide rail and ensures that the heat exchange device can be scanned once within 3 minutes. The sample coordinate system is perpendicular to the Bz axis magnetic induction intensity of the heat exchange device. The number of weak magnetic probes can be increased according to the surface area of the heat exchange device. This is not specifically limited in this embodiment.

[0108] The collected weak magnetic monitoring data is plotted as a curve. The abnormal magnetic induction intensity (peaks and valleys) is recorded, and the location of pitting corrosion of the heat exchanger is determined based on the coordinate position. Figure 5 This is a diagram of weak magnetic monitoring data in the heat exchange device pitting detection method of this embodiment, such as Figure 5 As shown in the figure, the horizontal axis is the distance from the leftmost end of the salt spray chamber (in cm), and the vertical axis is the magnetic induction intensity (in nT). The blue curve is the magnetic signal curve detected by the weak magnetic detector in the area where the heat exchange device is located before the experiment, and the orange curve is the magnetic signal curve detected by the weak magnetic detector in the area where the heat exchange device is located after the salt spray test for 1800 hours. Figure 5 As shown in the figure, by analyzing the waveform characteristics of the curve, the changing trend of the magnetic signal can be intuitively observed. In the weak magnetic monitoring data curve, the positions of the peaks and troughs usually correspond to the areas where pitting corrosion occurs on the surface of the heat exchanger. This is because pitting corrosion will cause abnormal changes in the local magnetic field, which will appear as obvious peaks or troughs on the curve. By analyzing the positions of these characteristic points, the specific location where the pitting corrosion occurs can be accurately determined. Figure 5 As shown in the figure, after 1800 hours of salt spray test, the heat exchanger had pitting defects at 20 cm, 53 cm, 92 cm and 117 cm away from the leftmost end of the salt spray chamber.

[0109] In particular, a weak magnetic detector is used to scan the surface of the heat exchange device and collect a large number of magnetic induction intensity differences between peaks and valleys ( At the same time, high-precision detection equipment (such as industrial CT scanning, profilometer, white light interferometer, etc.) is used to measure the actual pit depth at the corresponding position. The collected magnetic induction intensity difference ( ) and the actual pit depth data are sorted out, and a relationship expression between the two is established using computer fitting technology (such as the least squares method). The relationship expression obtained by fitting can be directly used to calculate the depth of the pit according to the weak magnetic detector. The pitting depth of the heat exchanger can be quickly calculated by using the value of the heat exchanger. This method improves detection efficiency and can also achieve efficient and accurate detection of the pitting depth of heat exchange components, providing strong support for the health management and preventive maintenance of heat exchange components.

[0110] In another embodiment, the process of performing a salt spray test on a heat exchange device further includes:

[0111] A constant current is applied to the heat exchange device based on a constant current meter, or a constant voltage is applied to the heat exchange device based on a constant potential meter to accelerate the corrosion rate of the heat exchange device during the salt spray test.

[0112] Specifically, in the above-mentioned process of performing pitting corrosion detection on the heat exchange device using an in-situ infrared thermal imager or performing pitting corrosion and pitting corrosion failure detection on the heat exchange device using an in-situ infrared thermal imager combined with a pressure monitoring device, in order to accelerate the corrosion rate of the salt spray test and shorten the salt spray test cycle, a constant current meter and a constant potentiostat are also introduced in this embodiment. Among them, the heat exchange device is connected to the positive electrode of the constant current meter, and the negative electrode is made of stainless steel or other suitable metal materials. By applying a constant current of 2mA-30mA for 1h-48h, the occurrence and development of pitting corrosion can be induced in a relatively short period of time, thereby accelerating the corrosion rate of the salt spray test and shortening the salt spray test cycle. The heat exchange device is connected to the positive electrode of the constant potentiostat, and the negative electrode is made of stainless steel or other suitable metal materials. By applying a constant voltage of 0.1-0.8V for 1h-48h, the occurrence and development of pitting corrosion can be induced in a relatively short period of time, thereby accelerating the corrosion rate of the salt spray test and shortening the salt spray test cycle. By using the electrochemical accelerated corrosion method, the corrosion process in a long-term salt spray environment can be simulated in a short period of time, and information on the occurrence and development of pitting corrosion can be quickly obtained.

[0113] In some embodiments, the process of performing a salt spray test on a heat exchange device further includes:

[0114] Whether pitting corrosion occurs in the heat exchange device can be determined by detecting the ion concentration of the heat exchange device by an in-situ concentration monitoring device connected to the interior of the heat exchange device; or by determining the pH value inside the heat exchange device by a pH meter connected to the interior of the heat exchange device.

[0115] Specifically, based on the above-mentioned pitting corrosion detection of heat exchange devices by in-situ infrared thermal imager or pitting corrosion and pitting corrosion failure detection of heat exchange devices by in-situ infrared thermal imager combined with pressure monitoring device, this embodiment also introduces an in-situ concentration monitoring device and pH meter to detect the pitting corrosion of the heat exchange device.

[0116] By connecting an in-situ concentration monitoring device inside the heat exchanger, the ion concentration inside the heat exchanger is monitored in real time. When pitting corrosion occurs in the heat exchanger, corrosion products dissolve into the solution, causing changes in ion concentration. For example, in metal heat exchangers, pitting corrosion can cause a significant increase in the concentration of metal ions (such as iron and copper ions). By monitoring changes in these ion concentrations, it is possible to determine whether pitting corrosion has occurred in the heat exchanger.

[0117] By connecting a pH meter inside the heat exchanger, the pH value inside the heat exchanger is monitored in real time. Pitting corrosion is often accompanied by localized corrosion reactions, which change the acidity or alkalinity of the solution. For example, in a salt spray test, corrosion reactions can lead to increased local acidity, resulting in a decrease in pH. By monitoring pH changes, especially when there is a significant decrease in pH, it is possible to determine whether pitting corrosion is occurring in the heat exchanger.

[0118] Both methods utilize in-situ monitoring technology, enabling real-time data acquisition during salt spray testing, enabling timely detection of the onset and progression of pitting corrosion. Changes in ion concentration and pH provide quantitative corrosion information, enabling more accurate assessment of the corrosion resistance of heat exchange components. Combining ion concentration and pH monitoring allows for a more comprehensive assessment of heat exchange component corrosion in salt spray environments, providing strong support for equipment maintenance and lifespan prediction.

[0119] This embodiment also provides a method for detecting pitting corrosion of a heat exchange device. Figure 6 This is a flow chart of another method for detecting pitting corrosion of a heat exchange device according to this embodiment. Figure 6 As shown, the process includes the following steps:

[0120] Step S601, obtaining a target infrared thermal image of the heat exchange device during a salt spray test on the heat exchange device;

[0121] Step S602: Detect the target area of the target infrared thermal image. If the target area exists in the target infrared thermal image, determine the target area.

[0122] Step S603: When only bright areas exist in the target area, the temperature difference between the bright areas in the target infrared thermal image and the bright areas of the surrounding intact areas and the shape of the bright areas in the target infrared thermal image are analyzed to obtain a first pitting corrosion result of the heat exchange component; the first pitting corrosion result is used as the target pitting corrosion result;

[0123] Step S604: When only a dark area exists in the target area, the temperature difference between the dark area in the target infrared thermal image and the dark area in the surrounding intact area and the area shape of the dark area in the target infrared thermal image are analyzed to obtain a second pitting corrosion result of the heat exchange component; the second pitting corrosion result is used as the target pitting corrosion result;

[0124] Step S605 , when the target area includes a bright area and a dark area, combining the first pitting corrosion result and the second pitting corrosion result to obtain a target pitting corrosion result.

[0125] Through the above steps S601 to S605, compared with the prior art method of cutting a sample of the heat exchange device and making a cross-section to observe the pitting corrosion of the heat exchange device, this embodiment collects a target infrared thermal image of the heat exchange device during the salt spray test, and analyzes and determines the temperature difference and shape of the target area (bright area and dark area) in the target infrared thermal image to obtain the pitting corrosion results and the cause of the pitting corrosion, thereby avoiding damage to the heat exchange device and achieving in-situ detection of pitting corrosion and pitting corrosion failure of automotive heat exchange devices.

[0126] In this embodiment, a heat exchange device pitting detection device is also provided. The heat exchange device pitting detection device is used to implement the above embodiments and preferred implementation methods, and the details that have been explained will not be repeated.

[0127] Figure 7 This is a structural block diagram of the heat exchange device pitting detection device of this embodiment. Figure 7 As shown, the heat exchange device pitting detection device 70 includes: an in-situ infrared thermal imager 71, a pressure monitoring device 72, a weak magnetic detector 73, a constant current meter 74, a constant potentiostat 75, an in-situ concentration monitoring device (not shown in the figure), a pH meter (not shown in the figure), and an analysis device (not shown in the figure); wherein:

[0128] The in-situ infrared thermal imager 71 is disposed outside the heat exchanger 76 and is used to capture a target infrared thermal image of the heat exchanger 76 and transmit the target infrared thermal image to an analysis device (not shown in the figure) so that the analysis device (not shown in the figure) can determine the pitting corrosion condition of the heat exchanger 76 based on the target infrared thermal image.

[0129] The pressure monitoring device 72 is provided at the inlet of the heat exchanger 76 and is used to detect the real-time pressure value of the heat exchanger 76 and transmit the real-time pressure value to an analysis device (not shown in the figure) so that the analysis device (not shown in the figure) can determine whether the heat exchanger 76 has suffered pitting failure based on the real-time pressure value;

[0130] The weak magnetic detector 73 is disposed around the heat exchanger 76 and is used to scan the area where the heat exchanger 76 is located to obtain weak magnetic monitoring data; and transmit the weak magnetic monitoring data to an analysis device (not shown in the figure), so that the analysis device (not shown in the figure) can analyze the weak magnetic monitoring data to determine the location of pitting corrosion in the heat exchanger 76;

[0131] The constant current meter 74 and the constant potentiostat 75 are connected to the heat exchange device 76 and are used to apply a constant current or a constant voltage to the heat exchange device 76 to accelerate the corrosion rate of the heat exchange device 76 during the salt spray test;

[0132] An in-situ concentration monitoring device (not shown) is disposed within the heat exchanger 76 and is used to detect the ion concentration of the heat exchanger 76 and transmit the ion concentration to an analysis device (not shown), so that the analysis device (not shown) can determine whether pitting corrosion has occurred in the heat exchanger 76 based on the ion concentration.

[0133] A pH meter (not shown) is disposed inside the heat exchange device 76 for detecting the pH value inside the heat exchange device 76 and transmitting the pH value to an analysis device (not shown in the figure) so that the analysis device (not shown in the figure) can determine whether pitting corrosion has occurred in the heat exchange device 76 based on the pH value.

[0134] It should be understood that the specific embodiments described herein are only used to explain this application and are not used to limit it. Based on the embodiments provided in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0135] Obviously, the accompanying drawings are merely examples or embodiments of the present application. A person skilled in the art can also apply the present application to other similar situations based on these drawings without inventive effort. Furthermore, it is understandable that, although the work involved in this development process may be complex and lengthy, certain design, manufacturing, or production changes based on the technical content disclosed in this application are merely routine technical means for a person skilled in the art and should not be considered to constitute a deficiency in the disclosure of the present application.

[0136] The term "embodiment" as used in this application refers to specific features, structures, or characteristics described in conjunction with the embodiment that can be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily mean that the embodiment is the same, nor does it mean that it is mutually exclusive with other embodiments and is independent or optional. It is understood, either explicitly or implicitly, by those skilled in the art that the embodiments described in this application can be combined with other embodiments when there is no conflict.

[0137] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the above-mentioned embodiments. In particular, any reference to memory, database, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The databases involved in the various embodiments provided herein may include at least one of a relational database and a non-relational database. Non-relational databases may include, but are not limited to, distributed databases based on blockchains. The processors involved in the various embodiments provided herein may be, but are not limited to, general-purpose processors, central processing units (CPUs), graphics processing units (GPUs), digital signal processors (DSPs), programmable logic devices (PLDs), data processing logic devices based on quantum computing, and the like.

[0138] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of patent protection. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A method for detecting pitting corrosion of a heat exchanger, characterized in that: include: During the salt spray test of the heat exchange device, obtaining a target infrared thermal image of the heat exchange device; Performing target area detection on the target infrared thermal image, and when the target area exists in the target infrared thermal image, determining the temperature difference between the target area and the surrounding area and the shape of the target area, wherein the target area includes a bright area and / or a dark area; When the target area includes only bright areas, analyzing the temperature difference between the bright areas in the target infrared thermal image and the surrounding intact areas and the area shape of the bright areas in the target infrared thermal image to obtain a first pitting corrosion result of the heat exchange device includes: When the temperature difference of the bright area is within a preset first temperature difference range, if the shape of the bright area is a small dot, it is determined that the tube wall of the heat exchange device is thinning and pitting cracking of the coating of the heat exchange device occurs; When the temperature difference of the bright area is within a preset second temperature difference range, if the shape of the bright area is a concentric ring or an elliptical ring, it is determined that the tube wall of the heat exchange device is thinning and the pitting corrosion of the heat exchange device is expanding in the circumferential direction; When the temperature difference of the bright area is within a preset second temperature difference range, if the shape of the bright area is a small dot or an irregular shape, it is determined that the tube wall of the heat exchange device is thinning and the pitting corrosion of the heat exchange device is extending along the wall; wherein the first temperature difference range is smaller than the second temperature difference range; When the target area includes only a dark area, analyzing the temperature difference between the dark area and the surrounding intact area in the target infrared thermal image and the area shape of the dark area in the target infrared thermal image to obtain a second pitting corrosion result of the heat exchange device includes: When the temperature difference of the dark area is within a preset third temperature difference range, and if the shape of the dark area is irregular, it is determined that the heat exchange device has an impurity quality defect; When the temperature difference of the dark area is within a preset fourth temperature difference range, if the shape of the dark area is a circle or an ellipse, it is determined that bubbling occurs in the coating of the heat exchange device and bubbles occur in the internal pipe of the heat exchange device; When the temperature difference of the dark area is within a preset fourth temperature difference range, if the shape of the dark area is a small dot or an irregular shape, it is determined that the heat exchange device has pitting failure; wherein the third temperature difference range is smaller than the fourth temperature difference range; When the target area includes a bright area and a dark area, the target pitting corrosion result is obtained by combining the first pitting corrosion result and the second pitting corrosion result.

2. The heat exchange device pitting detection method according to claim 1, characterized in that: During the salt spray test on the heat exchange device, the method further includes: Performing real-time pressure detection on the heat exchange device in a sealed state at the pipeline outlet to obtain a real-time pressure value; Calculating the pressure difference between the real-time pressure value and the initial pressure value; the initial pressure value is obtained by the initial detection when the heat exchange device is sealed; When the pressure difference reaches a preset pressure difference threshold, it is determined that pitting failure occurs in the heat exchange component, and a pitting failure warning message is issued.

3. The heat exchanger component pitting detection method according to claim 2, characterized in that: The method further comprises: determining, based on the pressure difference, a leakage amount of the heat exchange device causing pitting failure; The service life of the heat exchange device is determined according to the leakage amount.

4. The heat exchange device pitting detection method according to claim 1 or claim 2, characterized in that: During the salt spray test on the heat exchange device, the method further includes: Acquire weak magnetic field monitoring data of the area where the heat exchange device is located; Drawing a weak magnetic field monitoring data curve graph according to the weak magnetic field monitoring data; The locations of the peaks and troughs in the weak magnetic monitoring data curve are determined as locations where pitting corrosion occurs in the heat exchange device.

5. The heat exchange device pitting detection method according to claim 1 or claim 2, characterized in that: During the salt spray test on the heat exchange device, the method further includes: A constant current is applied to the heat exchange device based on a constant current meter, or a constant voltage is applied to the heat exchange device based on a constant potential meter, so as to accelerate the corrosion rate of the heat exchange device during the salt spray test.

6. The heat exchange device pitting detection method according to claim 1 or claim 2, characterized in that: During the salt spray test on the heat exchange device, the method further includes: determining whether pitting corrosion occurs in the heat exchange device based on an ion concentration of the heat exchange device detected by an in-situ concentration monitoring device connected to the interior of the heat exchange device; or, Whether pitting corrosion occurs in the heat exchange device is determined based on the pH value inside the heat exchange device detected by a pH meter connected to the inside of the heat exchange device.

7. A heat exchanger pitting detection device, used to implement the heat exchanger pitting detection method according to any one of claims 1 to 6, characterized in that: The heat exchange device pitting detection equipment includes: an in-situ infrared thermal imager, a pressure monitoring device, a weak magnetic detector, a constant current meter, a constant potential meter, an in-situ concentration monitoring device, a pH meter and an analysis device; wherein: The in-situ infrared thermal imager is arranged on the outside of the heat exchange device, and is used to collect a target infrared thermal image of the heat exchange device, and transmit the target infrared thermal image to the analysis device, so that the analysis device determines the pitting corrosion condition of the heat exchange device according to the target infrared thermal image; The pressure monitoring device is provided at the inlet of the heat exchange device, and is used to detect the real-time pressure value of the heat exchange device and transmit the real-time pressure value to the analysis device, so that the analysis device can determine whether the heat exchange device has pitting failure according to the real-time pressure value; The weak magnetic detector is arranged around the heat exchange device, and is used to scan the area where the heat exchange device is located to obtain weak magnetic monitoring data; and transmit the weak magnetic monitoring data to the analysis device, so that the analysis device can analyze the weak magnetic monitoring data to obtain the location where the pitting corrosion of the heat exchange device occurs; The constant current meter and the constant potentiostat are connected to the heat exchange device and are used to apply a constant current or a constant voltage to the heat exchange device to accelerate the corrosion rate of the heat exchange device during the salt spray test; The in-situ concentration monitoring device is arranged inside the heat exchange device, and is used to detect the ion concentration of the heat exchange device and transmit the ion concentration to the analysis device, so that the analysis device can determine whether the heat exchange device has pitting corrosion according to the ion concentration; The pH meter is arranged inside the heat exchange device, and is used to detect the pH value inside the heat exchange device and transmit the pH value to the analysis device, so that the analysis device can judge whether pitting corrosion occurs in the heat exchange device based on the pH value.

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