Method for operating a heat exchanger and device equipped with a heat exchanger

Abstract

It has a heat exchanger (12), the heat exchanger (12) has a pipe (14) for carrying a cooling medium, the pipe (14) is connected to a plurality of cooling fins (10) of the heat exchanger (12), has a fan (8) for conveying a volumetric air flow, has a heating device (16) for defrosting the heat exchanger (12), has a photographic imaging device (20), and has a control unit (22), the control unit (22) is set to detect the frozen state of the heat exchanger (12) and determine a defrosting time based on the evaluation of a first photographic image (56), the control unit (22) is set to control a defrosting operation performed by the heating device (16) based on the evaluation of a second photographic image (68), and the evaluation of the first photographic image (56) is different from the evaluation of the second photographic image (68).

Description

Technical Field

[0001] The present invention relates to an apparatus provided with a heat exchanger and a method for operating the heat exchanger of the apparatus.

Background Art

[0002] A heat exchanger is used to remove heat from a system to be cooled or introduce heat into a system to be heated. In the field of refrigeration technology, a heat exchanger is used to remove heat from a volume to be cooled by transferring a cooling medium from a liquid phase to a gas phase, and the heat exchanger is used as an evaporator. Similarly, a heat exchanger can be used to absorb ambient heat from the outside air in order to supply heat to a building to be heated in combination with a heat pump in the field of heating technology. Conversely, such a heat exchanger can also be used as a condenser or a rechiller for releasing heat to the environment.

[0003] Regardless of the specific application, it is important for the reliable and trouble-free function of the heat exchanger that the heat transfer between the heat exchanger and its surroundings is not restricted by obstructions that isolate the heat exchanger from the surroundings. Such obstructive effects include, for example, fouling or icing of the heat exchanger that may accumulate between the fins or fin packs of the heat exchanger.

[0004] Heat exchangers often have fins or fin packs to maximize the surface area available for heat transfer while keeping the size small. In the actual operation of such heat exchangers, moisture around the fins may condense on the fin surfaces, and the spaces between the fin surfaces and the fins may freeze. Due to this freezing insulation effect, the heat transfer between the environment of the heat exchanger and its fins, or between the corresponding fluid inside the heat exchanger, is impaired. Furthermore, the air flow through the heat exchanger deteriorates, the pressure loss increases, and the flow rate of the air passing through the heat exchanger decreases, resulting in a performance decline. In this state, the heat exchanger may not be able to provide the required cooling capacity or heat output. This may cause the cooled article to be damaged or the cooling system to malfunction. Additionally, the components of the heat exchanger may be damaged due to freezing.

[0005] To remove freezing, it is known to use a heating device to thaw the heat exchanger. Such thawing needs to be performed as efficiently as possible. If defrosting is carried out too frequently or takes too long, an unnecessarily large amount of heating energy is introduced into the volume to be cooled, and it is necessary to remove that heating energy using the heat exchanger to maintain or set the intended cooling temperature. If the frequency of defrosting is too low or the defrosting period is too short, the effect of defrosting cannot be obtained, and the function of the problematic system deteriorates. Well-known defrosting methods include electric defrosting, high-temperature gas defrosting, high-temperature brine defrosting, water or air defrosting, etc.

[0006] U.S. Patent No. 11,221,173 describes a defrosting device and method for a heat exchanger, where the formation of ice is monitored by an infrared camera and defrosting is controlled by the infrared camera. The formation of ice is evaluated based on the brightness in the image of the infrared camera, and there is a correlation that higher brightness indicates less ice formation and lower brightness indicates more ice formation. The drawback here is that the infrared camera is only suitable for monitoring the formation of ice and making a limited determination of the defrosting time, and the results are inaccurate. That is, defrosting may be too early or too late.

[0007] Korean Patent Publication No. 10-2041145 relates to a defrosting device and method for a heat exchanger that monitors the formation of ice by a camera and controls defrosting by the camera. The drawback here is that conventional cameras are not suitable for controlling defrosting and determining the end of defrosting, resulting in inaccurate results. That is, it means that the defrosting time may be too long or too short.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Summary of the Invention

[0009] Against such a background, the present invention is based on the technical problem of providing, in particular, a method for operating a heat exchanger and a device equipped with a heat exchanger that enable efficient defrosting and reliable operation of the heat exchanger.

[0010] According to a first aspect, the present invention provides the following method, that is, a step of operating a heat exchanger, a step of detecting the icing state of the heat exchanger and determining the defrosting time of the heat exchanger based on the evaluation of a first photographic image of the heat exchanger, and a step of starting a defrosting process of the heat exchanger executed by a heating device at the defrosting time and controlling the defrosting process based on the evaluation of a second photographic image of the heat exchanger, wherein the evaluation of the first photographic image is different from the evaluation of the second photographic image.

[0011] The fact that the evaluation used to determine the defrosting time is different from the evaluation used to control the defrosting process means that both the determination of the defrosting time and the control of the defrosting process can be improved. This is because the underlying tasks for the determination of the defrosting time and the control of the defrosting process are significantly different. For example, the purpose of determining the defrosting time and the evaluation on which this determination of the defrosting time is based is to observe and evaluate the state, that is, the frosting state of the heat exchanger, whereas the purpose of controlling the defrosting process is to defrost the heat exchanger by using the heating device as efficiently as possible. Therefore, due to the different designs of the evaluation of the first photographic image and the evaluation of the second photographic image, both the optimization of the determination of the defrosting time and the optimization of the control of the defrosting process can be carried out independently of each other without affecting or impairing each other. This ensures efficient defrosting and reliable operation of the heat exchanger.

[0012] The first photographic image may be a photographic image in the visible wavelength range.

[0013] A light source for illuminating the heat exchanger for photographic shooting in the visible wavelength range may be provided. Examples of such light sources include flash, lamp, etc.

[0014] When referring to the visible wavelength range in this specification, this refers to the wavelength range that can be recognized by the human eye. In particular, the wavelength range can have wavelengths from about 360 nanometers to 830 nanometers, particularly from about 400 nanometers to 780 nanometers. Therefore, the first photographic image can be comparable to a conventional photographic image generated by a conventional digital camera, which is also known in the consumer goods field.

[0015] Therefore, the evaluation of the first photographic image is particularly the evaluation of a digital photographic image in the visible wavelength range.

[0016] The first photographic image may be a photographic image of the infrared reflection of the heat exchanger. The first photographic image may be an infrared image of the heat exchanger.

[0017] An infrared light source such as an infrared spotlight that illuminates the heat exchanger can also be provided to capture an infrared image.

[0018] The evaluation of the first photographic image is performed by image evaluation software, and two or more reference images of the photographic image in the visible wavelength range are provided to the image evaluation software, and the comparison between the reference image and each first photographic image is performed by the image evaluation software. Based on such a comparison between the first photographic image and the reference image, the image evaluation software can be used, for example, to determine the amount of ice detected on the heat exchanger and to determine the defrosting time. This makes it easy to automate the determination of the defrosting time.

[0019] The image evaluation software can be AI-based. AI-based image evaluation has the advantage that the quality of image evaluation can be improved as the amount of data increases. AI-based image evaluation also has the advantage that evaluations can be applied to heat exchangers of various sizes and types using a common database.

[0020] When the abbreviation "AI" is used in this specification, it is an abbreviation for "artificial intelligence" and is synonymous with related topics such as "machine learning" and "deep learning".

[0021] Overall, the detection of the degree of icing of the heat exchanger and the necessary or unnecessary defrosting derived therefrom can be mapped as a classification problem by AI, a mapping function is generated using training data, and based on the image data, it is classified whether the degree of icing of the heat exchanger is critical or not, and defrosting is started, or the heat exchanger can continue to operate without defrosting initially. The mapping function may be further improved based on the image data processed during operation, thereby becoming a "learning" algorithm. In other words, as the amount of data increases, the quality of the imaging function improves.

[0022] The first reference image group of photographic images in the visible wavelength range shows the icing state of the heat exchanger that requires defrosting, and the second reference image group of photographic images in the visible wavelength range may show the icing state of the heat exchanger that does not require defrosting. Here, the defrosting time is defined by the image evaluation software when one or more of the first photographic images are assigned to the first reference image group in the visible wavelength range.

[0023] In particular, the reference images of photographic images in the visible wavelength range can be divided into two or more classes according to the degree of icing recognized on the reference images. For example, when a machine learning algorithm is used here, the reference images divided into classes are also called the training data of the classifier.

[0024] The reference images may be manually classified by skilled personnel. Alternatively or additionally, the reference images may be classified based on software. In this case, for example, one or more parameters such as sensor data when recording related reference images such as optically recognizable ice surfaces, pressure, temperature, etc. are considered.

[0025] When referred to as sensor data here, it includes environmental and / or refrigerant temperature data, in particular the pressure of the refrigerant at the inlet and outlet of the heat exchanger, air pressure, in particular the differential pressure between the ambient pressure and the pressure between the fan and the fin array. Here, for example, the pressure loss is measured on the fin array side away from the fan.

[0026] For example, the reference images of photographic images in the visible wavelength range may be divided into a maximum of 40 classes, in particular a maximum of 20 classes, and in particular further a maximum of 10 classes according to the degree of icing recognized on the reference images.

[0027] In particular, the reference images are assigned to a first group or a second group based on each class, with one or more classes assigned to the first group and one or more classes assigned to the second group, where the classes assigned to the first group are not assigned to the second group and vice versa. In particular, two or more classes may be assigned to each group.

[0028] Based on assigning the reference images to a first group or a second group based on each class, each class reflects the degree of freezing and a so-called target function can be defined, thereby enabling each first photographic image to be assigned to the first group or the second group.

[0029] According to a further design of this method, the second photographic image can be a photographic image in the non-visible wavelength range. When referring to the non-visible wavelength range here, this particularly refers to the wavelength range from 780 nm to 1 mm.

[0030] According to a further design of this method, the second photographic image can be a thermal image. Although there are some in this specification that do not refer to thermal images as "photographic images", in this specification, a thermal image is a photographic image or a photographic image in the non-visible wavelength range. A thermal image represents the temperature difference of an object.

[0031] Therefore, the second photographic image can particularly include infrared images and / or thermal images.

[0032] Therefore, the evaluation of the first photographic image and the evaluation of the second photographic image may be particularly different in that the first photographic image is a photographic image in the visible wavelength range and the second photographic image is a photographic image in the non-visible wavelength range. While the thawing time can be determined reliably and accurately by a photographic image in the visible wavelength range, the photographic image in the non-visible wavelength range has been shown to be particularly suitable for controlling the thawing process.

[0033] In particular, the non-visible wavelength range may be the infrared range.

[0034] The second photographic image can be evaluated using image evaluation software, and the image evaluation software is provided with two or more reference images of the photographic image in the non-visible wavelength range, and the reference images are compared with the respective second photographic images using the image evaluation software. Based on such comparison between the second photographic image and the reference image, the image evaluation software can be used, for example, to determine the amount of ice detected on the heat exchanger in order to determine the end of defrosting. This facilitates the automation of the determination of the end of defrosting.

[0035] The image evaluation software can be AI-based. AI-based image evaluation has the advantage that the quality of image evaluation can be improved as the amount of data increases. AI-based image evaluation also has the advantage that evaluations can be applied to heat exchangers of various sizes and types using a common database.

[0036] According to one design of the method, the first reference image group of the photographic image in the non-visible wavelength range shows the icing state of the heat exchanger that requires defrosting, and the second reference image group of the photographic image in the non-visible wavelength range is defined to show the icing state of the heat exchanger that does not require defrosting. When one or more of the second photographic images are assigned to the second reference image group of the photographic image in the non-visible wavelength range by the image evaluation software, the defrosting process ends.

[0037] The reference images of the photographic images in the non-visible wavelength region may be divided into two or more classes according to the degree of icing recognized on the reference images. For example, when a machine learning algorithm is used here, the reference images divided into classes are also called the training data of the classifier.

[0038] Furthermore, the reference images may be manually classified by skilled personnel. Alternatively or additionally, the reference images may be classified based on software. In this case, for example, one or more parameters such as sensor data at the time of recording related reference images such as optically recognizable ice surfaces, pressure, temperature, etc. are considered.

[0039] For example, reference images of photographic images in the non-visible wavelength range may be divided into up to 40 classes, particularly up to 20 classes, and particularly up to 10 classes according to the degree of freezing recognized on the reference images.

[0040] According to one design of the method, the reference images are assigned to a first group or a second group based on each class, one or more classes are assigned to the first group, one or more classes are assigned to the second group, the classes assigned to the first group are not assigned to the second group, and vice versa. In particular, two or more classes may be assigned to each group.

[0041] The evaluation of the second photographic image is a thermal image evaluation of the backscatter intensity in the non-visible wavelength range, and the second photographic image is a thermal image. Such a thermal image can be recorded using only the relevant sensors of the thermal imaging camera, particularly without using an external light source, to record the thermal signature of the heat exchanger. Conventional digital cameras and infrared cameras capture reflected light and may rely on additional light sources, but thermal imaging cameras do not require such light sources.

[0042] This type of thermal image evaluation enables precise control of the heating device to ensure reliable defrosting or defreezing on the one hand and avoid excessive heat input that is not necessary for defrosting on the other hand.

[0043] Furthermore, the thawing process can also be controlled using photographic images in the visible wavelength range. Therefore, according to one design of this method, both photographic images in the visible wavelength range and photographic images in the non-visible wavelength range are evaluated to control the thawing process.

[0044] To enable the second photographic image to be evaluated more accurately or improved, the second photographic image for evaluation may be provided in grayscale. Such grayscale representation enables an improved software-based evaluation of the photographic image in the non-visible wavelength range.

[0045] According to one design of the method, the first time interval existing between the provision and evaluation of two consecutive photographic images of the first photographic image can be defined to be greater than the second time interval existing between the provision and evaluation of two consecutive photographic images of the second photographic image.

[0046] In particular, the first interval can be two times or more, five times or more, ten times or more, or fifty times or more the second time interval. For example, the first time interval is 5 minutes, 10 minutes, 15 minutes, 30 minutes, 60 minutes or more, while the second time interval is less than 10 minutes, less than 5 minutes, or less than 1 minute. In practice, ice formation in the heat exchanger often occurs over a longer period, so a longer time interval is sufficient to monitor this ice formation and determine the defrost time. In contrast, defrosting is performed more quickly by the active heat input of the heating device, so a shorter time interval is used to monitor and control such a defrosting process to avoid excessive heat input by the heating device. The adaptation of the time interval is particularly useful for reducing the amount of data.

[0047] As the degree of icing increases, the first time interval can also be shortened. This prevents missing the optimal timing to start defrosting.

[0048] In addition to the photographic image, sensor data can be used to determine the icing state or defrost time and control the defrosting process. In that case, one or more of a temperature sensor, a pressure sensor, and a humidity sensor can be used.

[0049] For example, one or more sensor signals may be used to check the validity of the result of the evaluation of the first photographic image and / or the evaluation of the second photographic image. For example, in the evaluation of the first photographic image, it is shown that a critical freezing state requiring defrosting has been reached, but in the evaluation of one or more sensor signals, in contrast, it is shown that a critical freezing state has not been reached. In order to check the necessity of defrosting, an evaluation of one or more additional first photographic images can be performed. Alternatively or additionally, if the aforementioned sensor data conflicts with the evaluation of the first photographic image, an error message and / or a fault message can be output.

[0050] If the validity check is positive and a critical icing state is detected in both the one or more sensor signals and the evaluation of the first photographic image, the defrosting time can be determined.

[0051] This principle can also be applied when determining the end of defrosting.

[0052] The number of photographic imaging devices, particularly cameras, for taking the second photographic image may be greater than the number of cameras for taking the first photographic image.

[0053] Alternatively or additionally, only one photographic imaging device, particularly a camera, for taking the first photographic image may be provided.

[0054] Two or more photographic imaging devices, particularly cameras, may be provided for taking the second photographic image.

[0055] Alternatively or additionally, a plurality of photographic imaging devices, particularly cameras, for taking the second photographic image distributed along the longitudinal direction of the heat exchanger may be provided.

[0056] When referring to the determination of the defrosting time here, for example, once it is shown by the evaluation of the first photographic image that the frozen state requiring defrosting has been reached, defrosting may be started immediately. Alternatively, it may be possible to determine the future defrosting time based on the evaluation of the first photographic image. For example, using the frozen state, it is possible to determine a future time at which a critical frozen state that would impair the reliable operation of the heat exchanger may be reached, and set the defrosting time before this future time. This is because it is preferable that defrosting is performed at a time when the available output of the heat exchanger is reliably within a specified target output range.

[0057] The evaluation of the first photographic image and / or the evaluation of the second photographic image may be at least partially performed by a server, and the controller of the heating device may be connected to the server via a wired or wireless data connection.

[0058] Alternatively or additionally, the evaluation of the first photographic image and / or the evaluation of the second photographic image may be at least partially performed by a computer assigned to the heat exchanger and the heating device, and the controller of the heating device may be connected to the computer via a wired or wireless data connection.

[0059] Therefore, the evaluation can be performed online and / or offline. For example, establish a connection to the server as part of the initial setup of the heat exchanger to perform data comparison, and the evaluation is performed locally during operation using the device's computer. For example, the connection to the server can be established only at predefined intervals for further data comparison.

[0060] Alternatively, the evaluation of the first photographic image and / or the evaluation of the second photographic image may be performed only by the server, and not by the device's computer.

[0061] Alternatively, the evaluation of the first photographic image and / or the evaluation of the second photographic image may be performed only by the device's computer, and not by the server.

[0062] As a result of the evaluation of the first photographic image and / or as a result of the evaluation of the second photographic image, a service message and / or an alarm message can be generated and output.

[0063] The service message is, for example, a notification of maintenance requirements affecting a heat exchanger or a heating device. Such maintenance requirements are not considered urgent, meaning that the functions of the heat exchanger or heating device are not restricted at the time of the service notification.

[0064] The alarm message is a message regarding a partial or complete failure of the heat exchanger and / or the heating device, or a failure. Therefore, the alarm message informs that urgent and immediate measures are required to restore the functions of the heat exchanger and / or the heating device.

[0065] The number of photographic imaging devices, particularly cameras, for taking the second photographic image may be greater than the number of cameras for taking the first photographic image.

[0066] Alternatively or additionally, only one photographic imaging device, particularly a camera, for taking the first photographic image may be provided.

[0067] Two or more photographic imaging devices, particularly cameras, may be provided for taking the second photographic image.

[0068] Alternatively or additionally, a plurality of photographic imaging devices, particularly cameras, for taking the second photographic image distributed along the longitudinal direction of the heat exchanger may be provided.

[0069] This method may be a method for cooling a walk-in cooling volume.

[0070] This method may also be a method for heating a walk-in heating volume.

[0071] According to a second aspect, the invention relates to an apparatus having a heat exchanger. The heat exchanger has pipes for carrying a cooling medium, the pipes are connected to a plurality of cooling fins of the heat exchanger, has a fan for conveying the volumetric flow rate of air, has a heating device for defrosting the heat exchanger, has a photographic imaging device, and has a control unit. The control unit is configured to detect the frozen state of the heat exchanger and determine a defrosting time based on an evaluation of a first photographic image, and the control unit is configured to control a defrosting process executed by the heating device based on an evaluation of a second photographic image, and the evaluation of the first photographic image is different from the evaluation of the second photographic image.

[0072] The fact that the evaluation used to determine the defrosting time is different from the evaluation used to control the defrosting process means that both the determination of the defrosting time and the control of the defrosting process can be improved. This is because the respective tasks underlying the determination of the defrosting time and the control of the defrosting process are very different. For example, the purpose of determining the defrosting time and the evaluation on which this determination of the defrosting time is based is to observe and evaluate the state, i.e., the frozen state of the heat exchanger, whereas the purpose of controlling the defrosting process is to defrost the heat exchanger by using the heating device as efficiently as possible. Therefore, with the different designs of the evaluation of the first photographic image and the evaluation of the second photographic image, it becomes possible to optimize the determination of the defrosting time and the control of the defrosting process independently of each other without influencing or impairing each other.

[0073] All of the structural or functional features already described above with respect to the method in question can also be the subject matter of the apparatus according to the invention. Any aspect of the method described below with respect to the apparatus in question can be the subject matter of the method according to the invention.

[0074] The first photographic image may be a photographic image in the visible wavelength range. This may be the visible wavelength range described above with reference to the method of the present invention.

[0075] The second photographic image may be a photographic image in the non-visible wavelength range. This may be the non-visible wavelength range described above with reference to the method of the present invention.

[0076] The photographic imaging device may include a first camera equipped with a sensor for taking a photographic image in the visible wavelength range and a second camera equipped with a sensor for taking a photographic image in the non-visible wavelength range, or the photographic imaging device may include a camera for taking a photographic image in both the visible wavelength range and the non-visible wavelength range.

[0077] In particular, the photographic imaging device may be provided with an infrared camera and / or a thermal imaging camera. The photographic imaging device can be set to generate a photographic image in the visible wavelength range. The photographic imaging device can be set to generate a photographic image in the non-visible wavelength range, that is, in the form of an infrared image and / or a thermal image. The photographic imaging device can be set to generate a thermal image.

[0078] The photographic imaging device may be set to output a photographic image in the non-visible wavelength range in grayscale. In particular, the control unit may be set to process the second photographic image provided in grayscale.

[0079] One or more of a temperature sensor, a pressure sensor, and a humidity sensor are mounted on the device.

[0080] This device may be a cooling system for cooling a walk-in cooling volume.

[0081] This device may be a heating system for heating a walk-in heating volume.

[0082] In this specification, when referring to a heating device in relation to a method or apparatus, this may be, for example, an electric heating device having one or more heating rods, heating coils, or heating loops. Alternatively or additionally, a heating device that conducts fluid through a pipe can be provided. Alternatively or additionally, a heating device having a hot air heater can be provided. The heating device can be realized by the reverse operation of a heat exchanger. The heating device can have a brine defrosting system. Defrosting can be performed by electric defrosting, hot gas defrosting, warm brine defrosting, water defrosting, or air defrosting. The present invention will be described in more detail below with reference to the drawings showing exemplary embodiments. The drawings are schematically shown in each case.

Brief Description of the Drawings

[0083]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0084] Figure 1 shows an apparatus 2 according to the present invention. The apparatus 2 is a cooling system 2. The cooling system 2 can be used, for example, to cool a walk-in cooling volume.

[0085] The cooling system 2 has a housing 4 that supports a protective grill 6 for a fan 8 of the cooling system 2. The fan 8 is used to carry air from the environment U along the fins 10 of a heat exchanger 12 of the cooling system 2. The heat exchanger 12 will be described below with reference to FIG. 2.

[0086] Since the heat exchanger 12 is disposed inside the cooling system 2, the housing 4 is hidden in FIG. 2 in order to show the heat exchanger 12. The heat exchanger 12 has a number of flat or plate-like fins 10, and these fins 10 are arranged substantially parallel to each other along a longitudinal extension L of the heat exchanger 12.

[0087] The fins 10 are traversed by pipes 14 of the heat exchanger 12 that carry a cooling medium. The fins 10 are also referred to as cooling fins. The cooling fins 10 are connected to the pipes 14 of the heat exchanger 12.

[0088] The device 2 has a heating device 16 with a heating rod 18 for defrosting the heat exchanger 12. The heating rod 18 also passes through the cooling fins 10 along the longitudinal direction L and is connected to the cooling fins 10.

[0089] FIG. 3 shows the cooling fins 10 of the heat exchanger 12, the heating rod 18, and the pipes 14. According to FIG. 3, the heating rod 18 completely penetrates the fin 10 arrangement over its entire length along the longitudinal direction L.

[0090] FIG. 4 shows an alternative design of a heat exchanger 12' that can also be used in the device 2 according to the present invention. Unlike the heat exchanger 12 of FIG. 3, the heat exchanger 12' of FIG. 4 is provided with a heating rod 18' that penetrates only a partial length of the fin 10 arrangement when viewed along the longitudinal direction L.

[0091] As shown in FIG. 2, the apparatus 2 has an apparatus 20 for taking a photographic image. The apparatus 20 is used to generate a photographic image of the heat exchanger 12 and transmit it to the control unit 22 of the apparatus 2. The control unit 22 may have a computer for evaluating the photographic image, may be connected to a computer for evaluating the photographic image, and / or may be connected to a server for evaluating the photographic image.

[0092] The control unit 22 is set to detect the frozen state of the heat exchanger 12 and determine the defrosting time based on the evaluation of the first photographic image.

[0093] Furthermore, the control unit 22 is set to control the defrosting process executed by the heating device 16 based on the evaluation of the second photographic image, and the evaluation of the first photographic image is different from the evaluation of the second photographic image. The control unit 22 is also called the controller 22.

[0094] Both the first photographic image and the second photographic image are generated by the photographic imaging device 20 and transmitted to the control unit 22.

[0095] The photographic imaging device 20 is a camera 20 set for both photographic imaging in the visible wavelength range and photographic imaging in the non-visible wavelength range. For this purpose, it is equipped with a sensor 24 for performing corresponding imaging in the said wavelength range.

[0096] The apparatus 2 is also equipped with a temperature sensor 26, a pressure sensor 28, and a humidity sensor 30, and these sensors transmit signals to the control unit 22.

[0097] The apparatus 2 is set to execute the method according to the present invention described below.

[0098] The flowchart 32 in FIG. 6 relates to the operation of the heat exchanger 12 of the apparatus 2.

[0099] Block 34 of flowchart 32 describes the sensor level of the method and represents the signals from sensors 26, 28, and 30, as well as the provision of the first photographic image of heat exchanger 12 and / or the provision of the second photographic image of heat exchanger 12. Block 34 thus represents the input data of the method according to the invention, which is transmitted to database 36.

[0100] This data is processed or prepared in a further method step represented by block 38.

[0101] In step 40, it is checked whether heating device 16 is on or whether the defrosting process is currently active. If heating device 16 is not on and the defrosting process is not active, branch 42 is executed, which relates to the detection of the icing state of heat exchanger 12 and the determination of the defrosting time of heat exchanger 12. If heating device 16 is on and the defrosting process is active, branch 44 is executed, which relates to the control of the defrosting process.

[0102] First, the method steps of branch 42 will be described.

[0103] In method step 46, the first photographic image of heat exchanger 12 is evaluated, and this evaluation is performed using AI-based image evaluation software.

[0104] The first photographic image is a photographic image of heat exchanger 12 in the visible wavelength range. The photographic image is generated by photographic imaging device 20.

[0105] The AI model underlying method step 46 is generated using the training data represented by block 48. In particular, block 48 represents machine learning, i.e., a statistical model, based on reference images manually analyzed and classified by skilled personnel. Thus, the AI model is based on reference images of photographic images in the visible wavelength range, an example of which is shown in FIG. 5.

[0106] Here, the first group 50 shows a reference image 52 of a photographic image in the visible wavelength range regarding the frozen state of the heat exchanger 12 that requires defrosting. Further, the second group 54 shows a reference image 52 of a photographic image in the visible wavelength range regarding the frozen state of the heat exchanger 12 that does not require defrosting.

[0107] The reference image 52 of the photographic image in the visible wavelength range of the heat exchanger 12 is divided into 10 classes according to the degree of freezing recognized on the reference image 52. In this case, the reference image 52 is assigned consecutive numbers from I to X, and the degree of freezing increases as the number increases.

[0108] The reference images 52 with icing degrees I, II, III, IV, and V are assigned to the second group 54, and the reference images with icing degrees VI, VII, VIII, IX, and X are assigned to the first group 50.

[0109] The image 56 of the heat exchanger 12 in the visible wavelength range taken by the photographic imaging device 20 is assigned to classes I to X by the AI model 46 in the method step 58 shown in FIG. 6. Based on the assigned class, in the method step 60, it is determined whether defrosting is necessary based on the relevant groups 50 and 54.

[0110] When defrosting is not required, the branch 42 resumes as a loop according to the path 64 starting from the branch 62.

[0111] When defrosting is necessary, in order to initialize defrosting, the defrosting time is determined according to the block or method step 66. When the defrosting process is started, since the heating device 16 is on, the query or condition 40 leads to the branch 44, so the branch 44 of the flowchart 32 is executed.

[0112] The defrosting of the heat exchanger 12 is controlled by evaluating a second photographic image 68. The second photographic image 68 is generated by the photographic imaging device 20 and is an image of the heat exchanger 12 in the non-visible wavelength range.

[0113] The evaluation of the second photographic image 68 is also performed based on the AI model 70 generated based on the training data in the machine learning process according to method step 72. In particular, block 72 represents machine learning based on reference images manually evaluated and classified by skilled personnel, i.e., a statistical model.

[0114] Method steps 74 and 76 can be used to assign the photographic image 68 in the non-visible wavelength range to a class, in the same way as the procedure described above for the photographic image in the visible wavelength range, in order to stop the defrosting process according to the frozen state of the heat exchanger 12.

[0115] If the assignment of the photographic image 68 in the non-visible wavelength range to a class indicates that defrosting is still required, branch 44 is repeated according to path 80. If the assignment of the photographic image 68 in the non-visible wavelength range to a class indicates that no further defrosting is required, path 82 proceeds to method step 84 and the heating device 16 is turned off.

[0116] Since the heating device 16 is turned off, branch 42 is executed again within the loop until the necessary defrosting of the heat exchanger 12 is detected.

[0117] The signals from sensors 26, 28, 30 can be used to check the validity of the image evaluation both during the detection of the icing state and during the control of the defrosting process.

[0118] The first time interval existing between the provision and evaluation of two consecutive photographic images in the visible wavelength range may be defined to be greater than the second time interval existing between the provision and evaluation of two consecutive photographic images in the non-visible wavelength range.

[0119] According to another design, the photographic imaging device 20 is arranged within the housing 4. In particular, the photographic imaging device 20 is arranged within the housing 4 between the fan 8 and the heat exchanger 12.

[0120] The heat exchanger according to the alternative design may be, for example, a so-called microchannel heat exchanger having parallel pipes for guiding a cooling medium and fins arranged therebetween.

Explanation of Signs

[0121] 2 Apparatus / Cooling System 4 Housing 6 Protection Grill 8 Fan 10 Fins / Cooling Fins 12 Heat Exchanger 14 Pipe 16 Heating Device 18 Heating Rod U Environment L Longitudinal Direction B Width Direction 20 Photo Imaging Device 22 Control Unit 24 Sensor 26 Temperature Sensor 28 Pressure Sensor 30 Humidity Sensor 32 Flowchart 34 Block / Input Data / Input Signal 36 Database 38 Block / Processing 40 Condition / Branch 42 Branch “Detection of Freezing State” 44 Branch “Defrost Control” 46 AI Model / Evaluation 48 Training Data / Machine Learning 50 First Group of Reference Images 52 Reference Image 54 Second Group of Reference Images 56 Recording of Visible Wavelength Range 58 Method Step 60 Method Step 62 Condition / Branch 64 Path 66 Method Step 68 Recording of Non-Visible Wavelength Range 70 AI Model 72 Training data / Machine learning 74 Method steps 76 Method steps 78 Conditions / Branches 80 Path 82 Path 84 Method steps

Claims

1. A method comprising: operating a heat exchanger (12); detecting a frozen state of the heat exchanger (12) and determining a defrost time of the heat exchanger (12) based on an evaluation of a first photographic image (56) of the heat exchanger (12); starting a defrost process of the heat exchanger (12) to be executed by a heating device (16) at the defrost time and controlling the defrost process based on an evaluation of a second photographic image (68) of the heat exchanger; and the evaluation of the first photographic image (56) is different from the evaluation of the second photographic image (68). A method.

2. The first photographic image (56) is a photographic image in the visible wavelength range. The method according to claim 1, characterized in that.

3. The evaluation of the first photographic image (56) is performed by image evaluation software. Two or more reference images (52) of photographic images (52) in the visible wavelength range are provided to the image evaluation software. The comparison between the reference image (52) and each first photographic image (56) is performed by the image evaluation software. The method according to claim 2, characterized in that.

4. The image evaluation software is AI-based. The method according to claim 3, characterized in that.

5. A group (50) of first reference images (50) of the photographic images (52) in the visible wavelength range indicates a frozen state of the heat exchanger (12) and defrosting is required. A group (54) of second reference images (52) of the photographic images (52) in the visible wavelength range indicates a frozen state of the heat exchanger (12) and defrosting is not required. When one or more of the first photographic images (56) are assigned to the first group (50) of the photographic images in the visible wavelength range by the image evaluation software, a defrost time is defined. The method according to claim 3 or 4, characterized in that.

6. The reference images (52) of the photographic images (52) in the visible wavelength range are divided into two or more classes (I to X) according to the degree of icing recognized on the reference images (52). The method according to any one of claims 3 to 5, characterized in that.

7. The reference images (52) are assigned to the first group (50) or the second group (54) based on the respective classes (I to X). One or more classes (VI to X) are assigned to the first group (50). One or more classes (I to V) are assigned to the second group (54), The classes (I to X) assigned to the first group (50) are not assigned to the second group (54), and vice versa. The method according to claim 5 and claim 6, characterized in that.

8. The second photographic image (68) is a photographic image in the non-visible wavelength range. The method according to any one of claims 1 to 4, characterized in that.

9. The second photographic image (68) is evaluated using image evaluation software. Two or more reference images of the photographic image in the non-visible wavelength range are provided to the image evaluation software. The image evaluation software performs a comparison between the reference image and each second photographic image (68). The method according to claim 8, characterized in that.

10. The image evaluation software is AI-based. The method according to claim 9, characterized in that.

11. The first reference image group of the photographic image in the non-visible wavelength range shows the frozen state of the heat exchanger that requires defrosting, and the second reference image group of the photographic image in the non-visible wavelength range shows the frozen state of the heat exchanger that does not require defrosting. When one or more of the second photographic images (68) are assigned to the second reference image group of the photographic image in the non-visible wavelength range by the image evaluation software, the defrosting process ends. The method according to any one of claims 9 or 10, characterized in that.

12. The reference images of the photographic images in the non-visible wavelength range are divided into two or more classes according to the degree of icing recognized on the reference images. The method according to any one of claims 9 to 11, characterized in that.

13. The reference images are assigned to the first group or the second group based on each class. One or more classes are assigned to the first group. One or more classes are assigned to the second group. The classes assigned to the first group are not assigned to the second group, and vice versa. The method according to claim 11 or claim 12, characterized in that.

14. The evaluation of the second photographic image is a thermal image evaluation of the backscatter intensity in the non-visible wavelength range, and the second photographic image is a thermal image. The method according to any one of claims 8 to 13, characterized in that.

15. The method according to any one of claims 1 to 4, characterized in that the second photographic image for the evaluation is provided in grayscale.

16. The method according to any one of claims 1 to 15, characterized in that a first time interval existing between the provision of two consecutive photographic images of the first photographic image and the evaluation is greater than a second time interval existing between the provision of two consecutive photographic images of the second photographic image and the evaluation.

17. Determining a freezing state and / or a defrosting time and / or controlling a defrosting process using sensor data from one or more sensors among a temperature sensor (26), a pressure sensor (28), and a humidity sensor (30). The method according to any one of claims 1 to 16, characterized in that.

18. The evaluation of the first photographic image (56) and / or the evaluation of the second photographic image (68) are at least partially executed by a server, The controller (22) of the heating device is connected to the server via a wired or wireless data connection, and / or The evaluation of the first photographic image and / or the evaluation of the second photographic image are at least partially executed by a computer assigned to the heat exchanger and the heating device, The controller (22) of the heating device is connected to the computer via a wired or wireless data connection. The method according to any one of claims 1 to 17, characterized in that.

19. As a result of the evaluation of the first photographic image (56) and / or as a result of the evaluation of the second photographic image (68), a service message and / or an alarm message are generated and output, and / or The number of photographic imaging devices, particularly cameras, for taking the second photographic image (68) is greater than the number of cameras for taking the first photographic image (56), and / or Only one camera is provided as the photographic imaging device for taking the first photographic image (56), and / or Two or more cameras are provided as the photographic imaging device for taking the second photographic image (68), and / or A plurality of cameras are provided as the photographic imaging device for taking the second photographic image (68), and these are distributed along the longitudinal extension line of the heat exchanger (12). ​ ​ The method according to any one of claims 1 to 18, characterized in that...

20. An apparatus, comprising: a heat exchanger (12); the heat exchanger (12) having a pipe (14) for carrying a cooling medium; the pipe (14) being connected to a plurality of cooling fins (10) of the heat exchanger (12); a fan (8) for carrying an air flow; a heating device (16) for defrosting the heat exchanger (12); a photographic imaging device (20) for taking a photographic image; a control unit (22); the control unit (22) being configured to detect an icing state of the heat exchanger (12) and determine a defrosting time based on an evaluation of a first photographic image (56); the control unit (22) being configured to control a defrosting process performed by the heating device (16) based on an evaluation of a second photographic image (68); the evaluation of the first photographic image (56) being different from the evaluation of the second photographic image (68); An apparatus.

21. The apparatus according to claim 20, characterized in that the first photographic image (56) is a photographic image in the visible wavelength range.

22. The apparatus according to claim 20 or claim 21, characterized in that the second photographic image (68) is a photographic image in the non-visible wavelength range.

23. The photographic imaging device (20) comprises a first camera having a sensor for photographic imaging in the visible wavelength range and a second camera having a sensor for photographic imaging in the non-visible wavelength range, and / or the photographic imaging device (20) comprises a camera for photographic imaging in both the visible wavelength range and the non-visible wavelength range, and / or the photographic imaging device (20) comprises a thermal imaging camera, and / or the photographic imaging device (20) comprises an infrared camera. The apparatus according to any one of claims 20 to 22, characterized in that...

24. One or more sensors among a temperature sensor (26), a pressure sensor (28), and a humidity sensor (30) are provided, and / or the number of photographic imaging devices, particularly cameras, for taking the second photographic image (68) is greater than the number of cameras for taking the first photographic image (56), and / or only one photographic imaging device, particularly one camera, is provided for taking the first photographic image (56), and / or There are provided two or more photographic imaging devices, particularly cameras, for taking the second photographic image (68). and / or There are provided a plurality of photographic imaging devices, particularly cameras, for taking the second photographic image (68). These are dispersed along the longitudinal extension line of the heat exchanger (12). The device according to any one of claims 20 to 23, characterized in that.

25. The device (2) is set to execute the method according to any one of claims 1 to 19. The device according to any one of claims 20 to 24, characterized in that.

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