Air conditioner and frost detection device for heat exchanger
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-30
- Publication Date
- 2026-08-11
Smart Images
Figure CN224623049U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of air conditioning technology, specifically providing an air conditioner and a frost detection device for a heat exchanger. Background Technology
[0002] With the booming development of society and economy and the significant improvement in people's living standards, air conditioners, as key equipment for regulating indoor environments, are becoming increasingly popular in modern homes and commercial spaces. However, during air conditioner operation, especially under low-temperature heating conditions, frost formation frequently occurs on the surface of the heat exchanger. The frost layer hinders heat exchange between the air and the refrigerant, increases the thermal resistance of the heat exchanger surface, leading to a significant reduction in air conditioner heating efficiency and a significant increase in energy consumption. At the same time, frost also affects the air conditioner's airflow performance, causing indoor temperature fluctuations, reducing indoor comfort, and resulting in a poor user experience.
[0003] To address the issue of frost buildup on heat exchangers, timely and accurate defrosting detection is crucial. Currently, most air conditioner defrosting detection methods employ single-point detection technology, which uses only two electrodes to detect the frost layer in one direction. However, this method has significant limitations; it is highly susceptible to interference from foreign objects such as dust and leaves, which can be mistaken for frost, resulting in a high false positive rate. Frequent false positives trigger unnecessary defrosting operations, further increasing energy consumption and shortening the air conditioner's lifespan, failing to meet the demands of modern air conditioners for efficient and accurate defrosting detection. Utility Model Content
[0004] The present invention aims to solve the above-mentioned technical problems, namely, to at least solve the problem of low accuracy of defrosting detection in existing air conditioners.
[0005] In a first aspect, the present invention provides a frosting detection device for a heat exchanger, the heat exchanger comprising at least one first fin and at least one second fin spaced apart, the frosting detection device comprising:
[0006] At least one first electrode is disposed on the first fin;
[0007] At least one second electrode is disposed on the first fin at a distance from the first electrode, and the polarity of the second electrode is opposite to that of the first electrode;
[0008] At least one third electrode is disposed on the side of the second fin facing the first fin, and in the thickness direction of the fin, the third electrode is positioned opposite to the first electrode and has opposite polarities to it.
[0009] A resistance sensing assembly, wherein a first resistance sensing terminal is electrically connected to the first electrode, and a second resistance sensing terminal is electrically connected to the second electrode; and
[0010] A capacitance detection assembly, wherein its first capacitance detection terminal is electrically connected to the first electrode, and its second capacitance detection terminal is electrically connected to the third electrode.
[0011] In operation, this invention uses an electrode pair on the same side of the same fin and another electrode pair on the opposite side of adjacent fins. When frost on the same fin causes ice to replace the space between the two electrodes, it significantly affects the conductive cross-sectional area between the two electrodes. By detecting the resistance between the two electrodes, the ice-covered area on the fin surface can be obtained. Furthermore, when the space between corresponding electrodes of two adjacent fins is replaced by ice, it greatly affects the dielectric constant between the two capacitor plates. Therefore, by detecting the capacitance between the two electrodes on adjacent fins, the ice thickness between adjacent fins can be obtained. Combining the above two detection results, the frost condition on the heat exchanger surface can be grasped more accurately and timely, so that the air conditioner can enter defrosting mode at the appropriate time.
[0012] In some feasible embodiments of the above-described frosting detection device for heat exchangers, the first electrode, the second electrode, and the third electrode all extend along the length direction of the fins, and in the thickness direction of the fins, the projection of the third electrode at least partially overlaps with the projection of the first electrode.
[0013] In some feasible embodiments of the above-described frosting detection device for heat exchangers, the projection of the third electrode completely covers the projection of the first electrode.
[0014] In some feasible embodiments of the above-described frosting detection device for heat exchangers, the projection of the third electrode is larger than the projection of the first electrode.
[0015] In some feasible embodiments of the above-described frosting detection device for heat exchangers, there are multiple first electrodes and multiple second electrodes, with the multiple first electrodes and multiple second electrodes arranged alternately in the width direction of the first fin.
[0016] In some feasible embodiments of the above-described frosting detection device for heat exchangers, there are multiple third electrodes, which are spaced apart in the width direction of the second fin.
[0017] In some feasible embodiments of the frosting detection device for heat exchangers described above, a plurality of the first electrodes are interconnected with each other; and / or
[0018] Multiple second electrodes are interconnected with each other; and / or
[0019] The plurality of the third electrodes are interconnected with each other.
[0020] In some feasible embodiments of the above-described frosting detection device for heat exchangers, the first electrode and the second electrode are disposed on the first fin by embedding or bonding; and / or
[0021] The third electrode is disposed on the second fin by embedding or bonding.
[0022] In some feasible embodiments of the above-described frosting detection device for heat exchangers, the surfaces of the first fin that contact the first electrode and the second electrode, and the surface of the second fin that contacts the third electrode, are provided with an insulating layer.
[0023] In a second aspect, the present invention also provides an air conditioner, the air conditioner including a heat exchanger, and a frost detection device for the heat exchanger as described in any of the foregoing technical solutions.
[0024] Those skilled in the art will understand that, since the air conditioner includes the frost detection device for the heat exchanger described in any of the foregoing technical solutions, the air conditioner possesses all the technical effects that the aforementioned frost detection device can achieve, and will not be elaborated further here. Attached Figure Description
[0025] The preferred embodiments of this utility model are described below with reference to the accompanying drawings, in which:
[0026] Figure 1 A schematic diagram of the distribution structure of each electrode on the fins of the frost detection device for a heat exchanger provided in an embodiment of the present invention, showing the cross-section of the fins;
[0027] Figure 2 A plan view of the first electrode and the second electrode on the first fin of the frost detection device for a heat exchanger provided in an embodiment of the present invention, wherein the side surface of the first fin facing the second fin is shown.
[0028] Figure 3 A plan view of the third electrode on the second fin of the frost detection device for a heat exchanger provided in an embodiment of the present invention, showing the side surface of the second fin facing the first fin;
[0029] Figure 4 A planar distribution diagram of multiple interconnected first electrodes (or second electrodes) on a first fin of a frost detection device for a heat exchanger provided in an embodiment of the present invention.
[0030] Figure 5 A planar distribution diagram of multiple interconnected third electrodes on a second fin of a frost detection device for a heat exchanger provided in an embodiment of the present invention;
[0031] Figure 6 This is a schematic diagram of the installation of the copper tube for the frost detection device for a heat exchanger provided in an embodiment of the present invention.
[0032] Explanation of reference numerals in the attached figures:
[0033] 1. First fin; 11. First electrode; 12. Second electrode; 2. Second fin; 21. Third electrode; 3. Copper tube; 4. Transverse frost layer; 5. Longitudinal frost layer. Detailed Implementation
[0034] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention. Those skilled in the art can make adjustments as needed to adapt to specific applications. To better illustrate the present invention, numerous specific details are provided in the following detailed description. Those skilled in the art should understand that the present invention can be implemented even without certain specific details.
[0035] In the description of this utility model, terms such as "upper," "lower," "inner," "outer," "left," "right," "front," and "rear," which indicate direction or positional relationships, are based on the actual direction or positional relationships in practical application. These terms are used merely for ease of description and do not indicate or imply that the device to be protected must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, ordinal numbers such as "first" and "second" are used only for convenience of explanation and are not used to indicate or imply relative importance.
[0036] Furthermore, it should be noted that, in the description of this utility model, unless otherwise explicitly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0037] Please see Figures 1 to 6 This utility model provides a frost detection device for a heat exchanger. The heat exchanger includes at least one first fin 1 and at least one second fin 2 arranged at intervals. That is, the heat exchanger includes one or more sets of fin pairs for frost detection. Each set of fin pairs for frost detection includes one first fin 1 and one second fin 2, and the first fin 1 and the second fin 2 are arranged at intervals and opposite to each other. The specific number of fin pairs for frost detection is set according to actual needs. For ease of description, the following description uses one set of fin pairs for frost detection as an example.
[0038] The frosting detection device includes a resistance detection component, a capacitance detection component, at least one first electrode 11, at least one second electrode 12, and at least one third electrode 21.
[0039] In this configuration, at least one first electrode 11 is disposed on the first fin 1, and at least one second electrode 12 is disposed on the first fin 1 at a distance from the first electrode 11, wherein the polarity of the second electrode 12 is opposite to that of the first electrode 11.
[0040] Specifically, such as Figure 1 and Figure 2 As shown, arrow W points in the width direction of the first fin 1. The first fin 1 is equipped with first electrodes 11 and second electrodes 12 spaced apart along its width direction. When there are multiple first electrodes 11 and multiple second electrodes 12, the multiple first electrodes 11 and multiple second electrodes 12 are alternately arranged in the width direction of the first fin 1. Figure 2 As shown, the arrow L points in the direction of the length of the first fin 1. The first electrode 11 and the second electrode 12 are arranged parallel to each other, and both the first electrode 11 and the second electrode 12 extend along the length of the first fin 1.
[0041] At least one third electrode 21 is disposed on the side of the second fin 2 facing the first fin 1, and in the thickness direction of the fin, the third electrode 21 is positioned opposite to the first electrode 11 and has opposite polarities to each other.
[0042] Specifically, such as Figure 1 As shown, arrow T points in the direction of fin thickness. That is, the thickness directions of both the first fin 1 and the second fin 2 are along arrow T. Furthermore, in the fin thickness direction, the position of the third electrode 21 on the second fin 2 corresponds to the position of the first electrode 11 on the first fin 1. Figure 1 and Figure 3 As shown, the arrow W points in the width direction of the second fin 2. When there are multiple third electrodes 21, the multiple third electrodes 21 are arranged at intervals in the width direction of the second fin 2. The arrow L points in the length direction of the second fin 2, and the third electrodes 21 extend along the length direction of the second fin 2.
[0043] It should be noted that in this embodiment, the first electrode 11 can be a positive electrode and the second electrode 12 and the third electrode 21 can both be negative electrodes, or the first electrode 11 can be a negative electrode and the second electrode 12 and the third electrode 21 can both be positive electrodes, as long as the polarities of the first electrode 11 and the second electrode 12 are opposite, and the polarities of the first electrode 11 and the third electrode 21 are also opposite.
[0044] The first resistance detection terminal of the resistance detection component is electrically connected to the first electrode 11, and the second resistance detection terminal of the resistance detection component is electrically connected to the second electrode 12.
[0045] When frost forms on the surface of the first fin 1, the space between the first electrode 11 and the second electrode 12 is gradually occupied by the ice layer. At this time, the ice layer acts as a conductive medium between the first electrode 11 and the second electrode 12, leading to a significant change in the resistance between them. Based on this characteristic, since the first electrode 11 and the second electrode 12 almost cover the entire surface of the first fin 1, the changing trend of the ice-covered area on the surface of the first fin 1 can be indirectly inferred by monitoring the change in resistance between the first electrode 11 and the second electrode 12. This allows for the detection of the growth status of the transverse frost layer 4 on the fin.
[0046] Specifically, in the frost-free state, due to the excellent insulating properties of air, the first electrode 11 and the second electrode 12 are almost in an open circuit state, and the resistance value measured by the resistance detection component approaches infinity. However, as the laterally growing frost layer gradually spreads and connects the first electrode 11 and the second electrode 12, the resistance value measured by the resistance detection component drops sharply due to the conductivity of ice itself. Furthermore, as the area of the frost layer continues to expand, the connection area between the first electrode 11 and the second electrode 12 also increases, and the resistance value measured by the resistance detection component further decreases.
[0047] The first capacitance detection terminal of the capacitance detection component is electrically connected to the first electrode 11, and the second capacitance detection terminal of the capacitance detection component is electrically connected to the third electrode 21.
[0048] As the frost layer gradually accumulates and thickens, growing along the direction from the first fin 1 to the second fin 2 (or vice versa), the space between the first electrode 11 on the first fin 1 and the third electrode 21 on the second fin 2 will gradually be filled and occupied by the ice layer. At this time, the first electrode 11 and the third electrode 21 are equivalent to forming two parallel plates. This change in the ice layer will significantly affect the dielectric constant between the two capacitor plates formed. Based on this characteristic, the changing trend of the longitudinal frost layer 5 (frost layer along the thickness direction of the fin) between the fins can be indirectly inferred by detecting the capacitance value between the first electrode 11 and the third electrode 21, that is, the growth status of the frost layer in the longitudinal dimension can be detected.
[0049] Specifically, in a frost-free state, since the dielectric constant of air is approximately 1 and that of ice is approximately 3, the capacitance value measured by the capacitance detection component is relatively small. When frost begins to form on the surfaces of the first fin 1 and the second fin 2, the frost thickness is positively correlated with the capacitance value measured by the capacitance detection component between the first electrode 11 and the third electrode 21; that is, the thicker the frost layer, the higher the capacitance value. As the frost thickness continues to increase, the capacitance value measured by the capacitance detection component will further increase.
[0050] In this embodiment, the surfaces of the first fin 1 that contact the first electrode 11 and the second electrode 12, and the surfaces of the second fin 2 that contact the third electrode 21, are provided with insulating layers. Specifically, a dense aluminum oxide ceramic insulating layer can be formed on the fin surface, or an insulating layer can be formed by plasma spraying or other methods.
[0051] The first electrode 11 and the second electrode 12 are used to measure resistance to detect the frost on the surface of the first fin 1. If the first electrode 11 (or the second electrode 12) is conductive to the first fin 1, the measured resistance value will no longer be a true reflection of the resistance of the frost layer between the electrodes, but a mixed value that includes the resistance of the fin itself and the contact resistance between the electrode and the fin. After setting the insulating layer, it can be ensured that the resistance measurement only reflects the resistance change of the frost layer between the electrodes, thus improving the accuracy of the detection.
[0052] Similarly, the first electrode 11 and the third electrode 21 are used to measure capacitance. Capacitance measurement is usually based on the characteristics of the medium between the electrodes. If the third electrode 21 and the second fin 2 are conductive, the fin will become part of the capacitance detection, changing the structure and characteristics of the capacitor, resulting in inaccurate measurement results. After setting the insulating layer, it can be ensured that the capacitance measurement only reflects the capacitance characteristics of the medium between the electrodes, thus improving the accuracy of the detection.
[0053] The first electrode 11, the second electrode 12, and the third electrode 21 can be installed on the corresponding fins using specific mechanical fixing, bonding, or other installation methods to ensure a stable relative positional relationship between the electrodes and the fins, thereby meeting the requirements of subsequent resistance measurement, capacitance measurement, and other operations.
[0054] In one embodiment, the first electrode 11 and the second electrode 12 are attached to the first fin 1 by bonding, and the third electrode 21 is attached to the second fin 2 by bonding. This bonding method simply requires attaching the electrodes to the fin surface using a special adhesive, eliminating the need for complex processing equipment and installation techniques, and offering advantages such as simple operation and convenient installation.
[0055] In another embodiment, the first electrode 11 and the second electrode 12 are embedded in the first fin 1, and the third electrode 21 is embedded in the second fin 2. This embedded mounting method allows the electrodes to be partially enclosed by the fins, protecting them from external physical damage and effectively reducing interference from external electromagnetic fields and dust. This helps ensure stable and reliable resistance and capacitance measurements, accurately reflecting the frosting condition.
[0056] like Figure 4 As shown, when there are multiple first electrodes 11 and multiple second electrodes 12 on the first fin 1, the multiple first electrodes 11 can be interconnected with each other, and the multiple second electrodes 12 can be interconnected with each other. Figure 5 As shown, when there are multiple third electrodes 21 on the second fin 2, these electrodes 21 can be interconnected. In actual fin frosting monitoring, the frosting speed and degree in different areas often vary significantly. Adopting a design with multiple interconnected electrodes enables comprehensive coverage of all areas of the fin. This design is not limited to the measurement results of a single electrode, but rather uses multiple electrodes working collaboratively to comprehensively consider and reflect the frosting condition of the entire fin, thereby effectively expanding the effective detection area and enhancing the system's adaptability to complex operating conditions. Simultaneously, by integrating the signals from multiple electrodes, the cumbersome process of processing each electrode signal individually is avoided, reducing the pressure on signal processing and thus lowering the requirements for signal processing hardware and computational complexity.
[0057] The first electrode 11, the second electrode 12, and the third electrode 21 all extend along the length of the fin, and in the thickness direction of the fin, the projection of the third electrode 21 at least partially overlaps with the projection of the first electrode 11. When the capacitance detection assembly detects capacitance through the first electrode 11 and the third electrode 21, the overlapping portion of the projections between the electrodes ensures the effective facing area of the electrodes, enhances the coupling effect of the electric field, makes the detection signal more obvious, and helps to improve the accuracy of detection.
[0058] Building upon the aforementioned design, the projection of the third electrode 21 completely covers the projection of the first electrode 11. This maximizes the effective facing area between the electrodes, enhances the sensitivity of capacitance measurement, and more accurately captures subtle changes in frost thickness. It also avoids local measurement errors caused by uneven electric field distribution, improving the accuracy of capacitance measurement and thus more accurately reflecting the frost thickness distribution between the fins.
[0059] Further, please refer to Figure 4 and Figure 5When the projections are aligned, the projection of the third electrode 21 is larger than that of the first electrode 11. This is because if the two electrode plates are of similar size, the electric field is easily distorted in their edge regions, which can interfere with the measurement results. However, using a combination of a large and a small electrode plate can effectively alleviate this problem, reduce the occurrence of electric field distortion, and improve the accuracy of the measurement.
[0060] In addition, please see Figures 2 to 6 Arrow V indicates the airflow direction of the duct. The length directions of the first electrode 11, the second electrode 12, and the third electrode 21 are all parallel to the airflow direction of the duct. This arrangement ensures that the electrodes are distributed along the airflow direction, which helps reduce the air resistance generated by the electrodes. Figure 6 As shown, the heat exchanger also includes copper tubes 3, which are inserted between the fins in a manner perpendicular to the fins. This design makes the fins resemble heat dissipation wings extending outward from the copper tubes 3, giving full play to the role of the external heat diffusion components and facilitating efficient heat exchange between the copper tubes 3 and the surrounding airflow.
[0061] This utility model also provides an air conditioner, which includes a heat exchanger and a frost detection device for the heat exchanger as described in any of the foregoing technical solutions. Specifically, given that the evaporator of the air conditioner has a high probability of frost formation during operation, the heat exchanger is specifically the evaporator of the air conditioner.
[0062] Specifically, during detection, the real-time resistance between the first electrode 11 and the second electrode 12, and the real-time capacitance between the first electrode 11 and the third electrode 21 are obtained; the real-time resistance is compared with a preset resistance threshold, and the real-time capacitance is compared with a preset capacitance threshold; based on the comparison results of the real-time resistance and the preset resistance threshold, and the comparison results of the real-time capacitance and the preset capacitance threshold, the air conditioner is selectively activated to start the defrosting mode.
[0063] When the detected real-time resistance is less than or equal to the preset resistance threshold and the detected real-time capacitance is greater than or equal to the preset capacitance threshold, the system will control the air conditioner to start the defrosting mode. By using a combination of resistance and capacitance as a joint criterion for determining whether to enter the defrosting stage, the system can more accurately reflect the frost condition on the heat exchanger surface, thereby ensuring that the air conditioner enters the defrosting mode at the appropriate time. This not only removes the frost layer on the heat exchanger surface in a timely manner, ensuring that all functions of the air conditioner operate normally and maintaining its efficient and stable operating state, but also effectively avoids the problem of excessive false starts of the defrosting mode due to inaccurate detection, reducing unnecessary energy consumption and equipment wear and tear, and extending the service life of the air conditioner.
[0064] In operation, this invention uses an electrode pair on the same side of the same fin and another electrode pair on the opposite side of adjacent fins. When frost on the same fin causes ice to replace the space between the two electrodes, it significantly affects the conductive cross-sectional area between the two electrodes. By detecting the resistance between the two electrodes, the ice-covered area on the fin surface can be obtained. Furthermore, when the space between corresponding electrodes of two adjacent fins is replaced by ice, it greatly affects the dielectric constant between the two capacitor plates. Therefore, by detecting the capacitance between the two electrodes on adjacent fins, the ice thickness between adjacent fins can be obtained. Combining the above two detection results, the frost condition on the heat exchanger surface can be grasped more accurately and timely, so that the air conditioner can enter defrosting mode at the appropriate time.
[0065] The technical solution of this utility model has been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the protection scope of this utility model is obviously not limited to these specific embodiments. Without departing from the principle of this utility model, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of this utility model.
Claims
1. A frosting detection device for heat exchangers, characterized in that, The heat exchanger includes at least one first fin (1) and at least one second fin (2) spaced apart, and the frost detection device includes: At least one first electrode (11) is disposed on the first fin (1); At least one second electrode (12) is disposed on the first fin (1) at a distance from the first electrode (11), and the polarity of the second electrode (12) is opposite to that of the first electrode (11); At least one third electrode (21) is disposed on the side of the second fin (2) facing the first fin (1), and in the thickness direction of the fin, the third electrode (21) is positioned opposite to the first electrode (11) and has opposite polarities to each other. A resistance sensing assembly, wherein its first resistance sensing terminal is electrically connected to the first electrode (11), and its second resistance sensing terminal is electrically connected to the second electrode (12); and The capacitance detection assembly has a first capacitance detection terminal electrically connected to the first electrode (11) and a second capacitance detection terminal electrically connected to the third electrode (21).
2. The frosting detection device for heat exchangers according to claim 1, characterized in that, The first electrode (11), the second electrode (12) and the third electrode (21) all extend along the length direction of the fin, and in the thickness direction of the fin, the projection of the third electrode (21) at least partially overlaps with the projection of the first electrode (11).
3. The frosting detection device for heat exchangers according to claim 2, characterized in that, The projection of the third electrode (21) completely covers the projection of the first electrode (11).
4. The frosting detection device for a heat exchanger according to claim 3, characterized in that, The projection of the third electrode (21) is greater than the projection of the first electrode (11).
5. The frosting detection device for a heat exchanger according to claim 2, characterized in that, There are multiple first electrodes (11) and multiple second electrodes (12), and the multiple first electrodes (11) and multiple second electrodes (12) are arranged alternately in the width direction of the first fin (1).
6. The frosting detection device for a heat exchanger according to claim 5, characterized in that, There are multiple third electrodes (21), and the multiple third electrodes (21) are arranged at intervals in the width direction of the second fin (2).
7. The frosting detection device for a heat exchanger according to claim 6, characterized in that, The plurality of the first electrodes (11) are interconnected with each other; and / or The plurality of second electrodes (12) are interconnected with each other; and / or The plurality of the third electrodes (21) are interconnected with each other.
8. The frosting detection device for a heat exchanger according to claim 1, characterized in that, The first electrode (11) and the second electrode (12) are disposed on the first fin (1) by means of embedding or bonding; and / or The third electrode (21) is disposed on the second fin (2) by embedding or bonding.
9. The frosting detection device for a heat exchanger according to claim 1, characterized in that, The surfaces of the first fin (1) that contact the first electrode (11) and the second electrode (12), and the surfaces of the second fin (2) that contact the third electrode (21) are provided with an insulating layer.
10. An air conditioner, characterized in that, The air conditioner includes a heat exchanger and a frost detection device for the heat exchanger as described in any one of claims 1 to 9.