Defrosting control method and device, heat exchange unit and air conditioner

Abstract

The application discloses a defrosting control method and device, a heat exchange unit and an air conditioner. The method comprises the following steps: obtaining the exhaust temperature of a compressor after starting a defrosting operation; determining the frost formation reason according to the exhaust temperature; and controlling the frequency of the compressor according to the frost formation reason and the pipeline temperature of an indoor unit. According to the application, different compressor frequency control strategies can be set for the two frost formation reasons of insufficient refrigerant circulation and compressor liquid return, and the defrosting effect is improved.

Description

Technical Field

[0001] This invention relates to the field of generator set technology, and more specifically, to a defrosting control method, device, heat exchanger unit, and air conditioner. Background Technology

[0002] Existing evaporator defrosting technologies primarily involve installing temperature sensors on the copper tubes in the middle of the evaporator. When the sensor detects a temperature below a set value, it triggers either anti-freezing or defrosting action. This control method effectively prevents or resolves evaporator frosting when the refrigerant circulation is normal and there is no liquid return from the compressor. However, when the refrigerant circulation in the heat exchanger unit is insufficient, the compressor discharge pressure is high, resulting in a high discharge temperature; conversely, when liquid return from the compressor causes frosting, the compressor discharge temperature is low. Current technologies lack specific defrosting control strategies for these two scenarios, leading to poor defrosting performance.

[0003] There is currently no effective solution to the problem that existing technologies do not have specific defrosting control strategies based on the two causes of frost formation: insufficient refrigerant circulation and compressor liquid return, resulting in poor defrosting performance. Summary of the Invention

[0004] This invention provides a defrosting control method, device, heat exchange unit, and air conditioner to solve the problem in the prior art that the defrosting control strategy is not adjusted for two situations: the refrigerant circulation volume of the heat exchange unit or the compressor liquid return, resulting in poor defrosting effect.

[0005] To solve the above-mentioned technical problems, the present invention provides a defrosting control method, the method comprising:

[0006] After the defrosting operation begins, obtain the compressor's discharge temperature;

[0007] The cause of frosting is determined based on the exhaust temperature.

[0008] The compressor frequency is controlled based on the cause of frost formation and the pipe temperature of the indoor unit.

[0009] Furthermore, determining the cause of frosting based on the exhaust temperature includes:

[0010] Determine whether the exhaust temperature is lower than the preset temperature;

[0011] If so, then the cause of the frosting is determined to be compressor liquid return;

[0012] If not, then the cause of the frosting is determined to be insufficient refrigerant circulation.

[0013] Furthermore, controlling the compressor frequency based on the cause of frosting and the pipe temperature of the indoor unit includes:

[0014] If the cause of the frosting is determined to be compressor liquid return, then determine the temperature range of the indoor unit's piping temperature.

[0015] If the pipeline temperature is greater than a first threshold and less than or equal to a second threshold, the compressor's frequency ramp-up rate is reduced.

[0016] If the pipeline temperature is greater than the second threshold and less than or equal to the third threshold, then the compressor frequency is limited.

[0017] If the pipeline temperature is greater than the third threshold and less than or equal to the fourth threshold, the compressor is controlled to reduce its frequency according to the first preset speed.

[0018] If the pipeline temperature is greater than the fourth threshold and less than or equal to the fifth threshold, the compressor is controlled to reduce its frequency at a second preset speed; wherein the second preset speed is greater than the first preset speed.

[0019] If the pipeline temperature is greater than the fifth threshold and less than or equal to the sixth threshold, the compressor is controlled to stop.

[0020] Furthermore, controlling the compressor frequency based on the cause of frosting and the pipe temperature of the indoor unit includes:

[0021] If the cause of the frosting is determined to be insufficient refrigerant circulation, then determine the temperature range of the indoor unit's piping temperature.

[0022] If the pipeline temperature is greater than the seventh threshold and less than or equal to the eighth threshold, the compressor's frequency ramp-up rate is reduced.

[0023] If the pipeline temperature is greater than the eighth threshold and less than or equal to the ninth threshold, then the compressor frequency is limited.

[0024] If the pipeline temperature is greater than the ninth threshold and less than or equal to the tenth threshold, then the compressor is controlled to reduce its frequency according to the first preset speed.

[0025] If the pipeline temperature is greater than the tenth threshold and less than or equal to the eleventh threshold, the compressor is controlled to reduce its frequency at a second preset speed; wherein the second preset speed is greater than the first preset speed.

[0026] If the pipeline temperature is greater than the eleventh threshold and less than or equal to the twelfth threshold, then the compressor is controlled to stop.

[0027] Wherein, the seventh threshold is greater than the first threshold, the eighth threshold is greater than the second threshold, the ninth threshold is greater than the third threshold, the tenth threshold is greater than the fourth threshold, the eleventh threshold is greater than the fifth threshold, and the twelfth threshold is greater than the sixth threshold.

[0028] Furthermore, before initiating the defrosting operation, the method further includes:

[0029] Determine whether the pipeline temperature and the exhaust temperature meet preset conditions;

[0030] If so, then control the heat exchange unit to start the defrosting operation;

[0031] If not, then control the heat exchange unit to operate normally.

[0032] Furthermore, the preset conditions include:

[0033] The pipeline temperature continuously decreases for a first preset time period and remains above 0°C; and...

[0034] The exhaust temperature continuously decreases for a second preset time.

[0035] The present invention also provides a defrosting control device, the device comprising:

[0036] The parameter acquisition module is used to acquire the compressor's exhaust temperature after the defrosting operation begins.

[0037] The determination module is used to determine the cause of frosting based on the exhaust temperature;

[0038] The control module is used to control the frequency of the compressor based on the cause of frosting and the pipe temperature of the indoor unit.

[0039] The present invention also provides a heat exchange unit including the above-mentioned defrosting control device and applying the above-mentioned defrosting control method.

[0040] The present invention also provides an air conditioner, including the above-described heat exchange unit.

[0041] The present invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-described defrosting control method.

[0042] By applying the technical solution of this invention, the cause of frost is first determined based on the compressor's exhaust temperature. Then, different compressor frequency control strategies are set for the two causes of frost: insufficient refrigerant circulation and compressor liquid return. This enables targeted defrosting and improves the defrosting effect. Attached Figure Description

[0043] Figure 1A flowchart of a defrosting control method according to an embodiment of the present invention;

[0044] Figure 2 A flowchart of a defrosting control method according to another embodiment of the present invention has been obtained;

[0045] Figure 3 This is a structural block diagram of a defrosting control device according to an embodiment of the present invention. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0047] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” as used in the embodiments of this invention and the appended claims are also intended to include the plural forms, and “multiple” generally includes at least two unless the context clearly indicates otherwise.

[0048] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0049] It should be understood that although the terms first, second, third, etc., may be used to describe thresholds in the embodiments of the present invention, these thresholds should not be limited to these terms. These terms are only used to distinguish different temperature thresholds. For example, without departing from the scope of the embodiments of the present invention, the first threshold may also be referred to as the second threshold, and similarly, the second threshold may also be referred to as the first threshold.

[0050] Depending on the context, the words “if” or “suppose” as used here can be interpreted as “when” or “in response to determination” or “in response to detection.” Similarly, depending on the context, the phrases “if determination” or “if detection (of the stated condition or event)” can be interpreted as “when determination” or “in response to determination” or “when detection (of the stated condition or event)” or “in response to detection (of the stated condition or event).”

[0051] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or device. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or device that includes said element.

[0052] The optional embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0053] Example 1

[0054] Existing evaporator defrosting technologies primarily involve installing temperature sensors on the copper tubes in the middle of the evaporator. When the sensor detects a temperature below a set value, it triggers either anti-freezing or defrosting action. This control method effectively prevents or resolves evaporator frosting when the refrigerant circulation is normal and there is no liquid return from the compressor. However, when the refrigerant circulation in the heat exchanger unit is insufficient, the compressor discharge pressure is high, resulting in a high discharge temperature; conversely, when liquid return from the compressor causes frosting, the compressor discharge temperature is low. Current technologies lack specific defrosting control strategies for these two scenarios, leading to poor defrosting performance.

[0055] To address the aforementioned technical problems, this embodiment provides a defrosting control method. Figure 1 A flowchart of a defrosting control method according to an embodiment of the present invention is shown below. Figure 1 As shown, the method includes:

[0056] S101, after the defrosting operation begins, obtains the compressor's exhaust temperature.

[0057] S102, determine the cause of frosting based on the compressor's exhaust temperature.

[0058] The causes of frosting include insufficient refrigerant circulation and compressor liquid return.

[0059] S103, based on the above-mentioned causes of frost and the pipe temperature of the indoor unit, control the compressor frequency.

[0060] The defrosting control method in this embodiment first determines the cause of frost based on the compressor's exhaust temperature, and then sets different compressor frequency control strategies for the two causes of frost: insufficient refrigerant circulation and compressor liquid return. This enables targeted defrosting and improves the defrosting effect.

[0061] As mentioned earlier, when the refrigerant circulation in the heat exchanger unit is insufficient, the compressor discharge pressure is high, resulting in a high discharge temperature. Conversely, when liquid return from the compressor causes frost, the compressor discharge temperature is low. Therefore, the discharge temperature can indicate the cause of frost. Determining the cause of frost based on the discharge temperature includes: checking if the discharge temperature is lower than the preset temperature; if so, the cause of frost is determined to be liquid return from the compressor; if not, the cause of frost is determined to be insufficient refrigerant circulation. The preset temperature is the discharge temperature of the heat exchanger unit during normal operation.

[0062] After defrosting begins, the temperature drop in the indoor unit's pipes will gradually turn into an increase. When the indoor unit's pipe temperature exceeds the defrost threshold, the heat exchange unit will exit defrosting and return to normal operation. However, if the indoor unit's pipe temperature rises too quickly, the frost may not be completely removed before exiting defrost mode, causing the frost layer on the evaporator to accumulate thicker and thicker, affecting heat exchange efficiency. Therefore, after performing defrosting, the compressor frequency needs to be adjusted, successively by slowing down the frequency increase rate, limiting the frequency, reducing the frequency at normal speed, and then rapidly reducing the frequency, to control the rate of temperature rise in the indoor unit's pipes. When compressor liquid return causes frost formation, the compressor's discharge temperature is low. The indoor unit's pipe temperature is positively correlated with the compressor's discharge temperature. That is, when compressor liquid return causes frost formation, the indoor unit's pipe temperature is low when defrosting begins. Therefore, the temperature thresholds for performing various frequency adjustment operations should also be lowered accordingly to ensure that the defrosting process does not end prematurely.

[0063] Therefore, the compressor frequency is controlled based on the cause of frosting and the pipe temperature of the indoor unit, including: if the cause of frosting is determined to be compressor liquid return, the temperature range of the indoor unit's pipe temperature is determined; if the pipe temperature is greater than a first threshold and less than or equal to a second threshold, the compressor's frequency increase rate is reduced; if the pipe temperature is greater than the second threshold and less than or equal to a third threshold, the compressor's frequency is limited; if the pipe temperature is greater than the third threshold and less than or equal to a fourth threshold, the compressor's frequency is reduced according to a first preset speed; if the pipe temperature is greater than the fourth threshold and less than or equal to a fifth threshold, the compressor's frequency is reduced according to a second preset speed; wherein, the second preset speed is greater than the first preset speed; if the pipe temperature is greater than the fifth threshold and less than or equal to a sixth threshold, the compressor is stopped.

[0064] When the refrigerant circulation in the heat exchanger unit is insufficient, the compressor discharge pressure is high, resulting in a high discharge temperature. In other words, when insufficient refrigerant circulation causes frosting, the indoor unit's pipe temperature is high when defrosting begins. Therefore, the temperature thresholds for various frequency adjustment operations should be increased accordingly. Thus, if insufficient refrigerant circulation is determined to be the cause of frosting, the temperature range of the indoor unit's pipe temperature is assessed. If the pipe temperature is greater than the seventh threshold but less than or equal to the eighth threshold, the compressor's frequency ramp-up rate is reduced. If the pipe temperature is greater than the eighth threshold but less than or equal to the ninth threshold, the compressor's frequency ramp-up rate is reduced. Frequency limiting; if the pipeline temperature is greater than the ninth threshold and less than or equal to the tenth threshold, the compressor is controlled to reduce its frequency at the first preset speed; if the pipeline temperature is greater than the tenth threshold and less than or equal to the eleventh threshold, the compressor is controlled to reduce its frequency at the second preset speed; wherein the second preset speed is greater than the first preset speed; if the pipeline temperature is greater than the eleventh threshold and less than or equal to the twelfth threshold, the compressor is controlled to stop; wherein the seventh threshold is greater than the first threshold, the eighth threshold is greater than the second threshold, the ninth threshold is greater than the third threshold, the tenth threshold is greater than the fourth threshold, the eleventh threshold is greater than the fifth threshold, and the twelfth threshold is greater than the sixth threshold.

[0065] When the refrigerant circulation in the heat exchanger unit is insufficient, the following situations may prevent timely antifreeze or defrosting: The evaporator inlet temperature is below the freezing point, and frost begins to form at the evaporator inlet. Due to insufficient refrigerant circulation, after heat exchange with the air, the temperature in the middle of the evaporator is higher than or far above the freezing point of water. At this time, the temperature detected by the sensor located in the middle of the evaporator does not meet the conditions for antifreeze or defrosting action. As the unit operates, the frost at the evaporator inlet gradually thickens and spreads towards the evaporator outlet. At this time, the temperature in the middle of the evaporator will also gradually decrease. When the conditions for antifreeze or defrosting action are met, the antifreeze or defrosting action will be executed. Because a large amount of frost accumulates at the evaporator inlet, the frost on the evaporator cannot be completely melted after the antifreeze or defrosting action is executed. It will gradually accumulate during subsequent operation, leading to a rapid decrease in the heat exchange efficiency of the heat exchanger unit, frost clogging the drain outlet causing water leakage, and even system failure. Therefore, controlling the defrosting and defrosting stop points by setting sensors on the evaporator to detect temperature is inaccurate. Thus, this embodiment uses whether the pipe temperature and exhaust temperature continuously decrease as defrosting determination conditions to decide whether to perform defrosting. Before starting the defrosting operation, it is determined whether the pipe temperature and exhaust temperature meet preset conditions; if so, the heat exchange unit is controlled to start the defrosting operation; if not, the heat exchange unit is controlled to operate normally. The preset conditions include: the pipe temperature continuously decreases for a first preset time and always remains above 0°C; and the exhaust temperature continuously decreases for a second preset time.

[0066] Example 2

[0067] This embodiment provides another defrosting control method. Figure 2 A flowchart of a defrosting control method according to another embodiment of the present invention is provided, as follows: Figure 2 As shown, the method includes:

[0068] S1. Determine whether the following conditions are met: the pipe temperature of the indoor unit continuously decreases for a duration of t1 and remains above 0°C; and the exhaust temperature continuously decreases for a duration of t2. If yes, proceed to step S3; otherwise, proceed to step S2.

[0069] When the refrigerant circulation in the heat exchanger unit is insufficient, the following situations may prevent timely antifreeze or defrosting: The evaporator inlet temperature is below the freezing point, and frost begins to form at the evaporator inlet. Due to insufficient refrigerant circulation, after heat exchange with the air, the temperature in the middle of the evaporator is higher than or far above the freezing point of water. At this time, the temperature detected by the sensor located in the middle of the evaporator does not meet the conditions for antifreeze or defrosting action. As the unit operates, the frost at the evaporator inlet gradually thickens and spreads towards the evaporator outlet. At this time, the temperature in the middle of the evaporator will also gradually decrease. When the conditions for antifreeze or defrosting action are met, the antifreeze or defrosting action will be executed. Because a large amount of frost accumulates at the evaporator inlet, the frost on the evaporator cannot be completely melted after the antifreeze or defrosting action is executed. It will gradually accumulate during subsequent operation, leading to a rapid decrease in the heat exchange efficiency of the heat exchanger unit, frost clogging the drain outlet causing water leakage, and even system failure. Therefore, it is inaccurate to control the defrosting and defrosting stop points by setting a sensor on the evaporator to detect the temperature. Therefore, this embodiment uses whether the pipeline temperature and the exhaust temperature continue to drop as defrosting determination conditions to determine whether to perform defrosting.

[0070] S2 controls the normal operation of the heat exchange unit.

[0071] S3 controls the heat exchanger unit to begin defrosting.

[0072] S4. Determine if the compressor's discharge temperature is greater than the preset temperature Tp; if yes, proceed to step S5; otherwise, proceed to step S11. The preset temperature Tp is the discharge temperature of the heat exchanger unit during normal operation.

[0073] S5, determine the temperature range of the indoor unit's pipe temperature; if T1 < pipe temperature ≤ T2, proceed to step S6; if T2 < pipe temperature ≤ T3, proceed to step S7; if T3 < pipe temperature ≤ T4, proceed to step S8; if T4 < pipe temperature ≤ T5, proceed to step S9; if T5 < pipe temperature ≤ T6, proceed to step S10.

[0074] S6 controls the compressor's frequency ramp-up speed to decrease.

[0075] S7 controls the compressor frequency limit.

[0076] S8 controls the compressor to reduce its frequency at constant speed.

[0077] S9 controls the compressor to quickly reduce its frequency.

[0078] S10 controls the compressor to stop.

[0079] After defrosting begins, the temperature drop in the indoor unit's pipes will gradually turn into an increase. When the indoor unit's pipe temperature exceeds the defrost threshold, the heat exchange unit will exit defrosting and return to normal operation. However, if the indoor unit's pipe temperature rises too quickly, the frost may not be completely removed before exiting defrost mode, causing the frost layer on the evaporator to accumulate thicker and thicker, affecting heat exchange efficiency. Therefore, after performing defrosting, the compressor frequency needs to be adjusted, successively by slowing down the frequency increase rate, limiting the frequency, reducing the frequency at normal speed, and then rapidly reducing the frequency, to control the rate of temperature rise in the indoor unit's pipes. When compressor liquid return causes frost formation, the compressor's discharge temperature is low. The indoor unit's pipe temperature is positively correlated with the compressor's discharge temperature. That is, when compressor liquid return causes frost formation, the indoor unit's pipe temperature is low when defrosting begins. Therefore, the temperature thresholds for performing various frequency adjustment operations should also be lowered accordingly to ensure that the defrosting process does not end prematurely.

[0080] S11. Determine the temperature range of the pipeline. If T7 < pipeline temperature ≤ T8, proceed to step S12; if T8 < pipeline temperature ≤ T9, proceed to step S13; if T9 < pipeline temperature ≤ T10, proceed to step S14; if T10 < pipeline temperature ≤ T11, proceed to step S15; if T11 < pipeline temperature ≤ T12, proceed to step S16.

[0081] S12 controls the compressor's frequency ramp-up speed to decrease.

[0082] S13 controls the compressor frequency limit.

[0083] S14 controls the compressor to reduce its frequency from constant speed.

[0084] S15 controls the compressor to quickly reduce its frequency.

[0085] S16 controls the compressor to stop.

[0086] Among them, T7 > T1, T8 > T2, T9 > T3, T10 > T4, T11 > T5, T12 > T6.

[0087] When the refrigerant circulation of the heat exchanger unit is insufficient, the compressor discharge pressure is high, resulting in a high discharge temperature. In other words, when the refrigerant circulation of the heat exchanger unit is insufficient and frosting occurs, the indoor unit's pipe temperature is high when defrosting begins. Therefore, the temperature threshold for performing various frequency adjustment operations should also be increased accordingly.

[0088] Example 3

[0089] This embodiment provides a defrosting control device. Figure 3 This is a structural block diagram of a defrosting control device according to an embodiment of the present invention, such as... Figure 3 As shown, the device includes:

[0090] The parameter acquisition module 10 is used to acquire the compressor's exhaust temperature after the defrosting operation begins.

[0091] The determination module 20 is used to determine the cause of frosting based on the exhaust temperature. The causes of frosting include insufficient refrigerant circulation and compressor liquid return.

[0092] The control module 30 is used to control the compressor frequency based on the cause of frosting and the pipe temperature of the indoor unit.

[0093] In this embodiment of the defrosting control device, the determining module 20 first determines the cause of frost based on the compressor's exhaust temperature. The control module 30 sets different compressor frequency control strategies for the two causes of frost: insufficient refrigerant circulation and compressor liquid return, which can achieve targeted defrosting and improve the defrosting effect.

[0094] As mentioned earlier, when the refrigerant circulation in the heat exchanger unit is insufficient, the compressor discharge pressure is high, resulting in a high discharge temperature; conversely, when liquid return from the compressor causes frost, the compressor discharge temperature is low. Therefore, the discharge temperature can indicate the cause of frost. Thus, when determining the cause of frost based on the discharge temperature, module 20 specifically performs the following operation: It checks whether the discharge temperature is lower than a preset temperature; if so, the cause of frost is determined to be liquid return from the compressor; if not, the cause of frost is determined to be insufficient refrigerant circulation. The preset temperature is the discharge temperature of the heat exchanger unit during normal operation.

[0095] After defrosting begins, the temperature drop in the indoor unit's pipes will gradually turn into an increase. When the indoor unit's pipe temperature exceeds the defrost threshold, the heat exchange unit will exit defrosting and return to normal operation. However, if the indoor unit's pipe temperature rises too quickly, the frost may not be completely removed before exiting defrost mode, causing the frost layer on the evaporator to accumulate thicker and thicker, affecting heat exchange efficiency. Therefore, after performing defrosting, the compressor frequency needs to be adjusted, successively by slowing down the frequency increase rate, limiting the frequency, reducing the frequency at normal speed, and then rapidly reducing the frequency, to control the rate of temperature rise in the indoor unit's pipes. When compressor liquid return causes frost formation, the compressor's discharge temperature is low. The indoor unit's pipe temperature is positively correlated with the compressor's discharge temperature. That is, when compressor liquid return causes frost formation, the indoor unit's pipe temperature is low when defrosting begins. Therefore, the temperature thresholds for performing various frequency adjustment operations should also be lowered accordingly to ensure that the defrosting process does not end prematurely.

[0096] Therefore, when the control module 30 controls the compressor frequency based on the cause of frost and the pipe temperature of the indoor unit, the specific operations performed are as follows: if the cause of frost is determined to be compressor liquid return, the temperature range of the indoor unit's pipe temperature is determined; if the pipe temperature is greater than the first threshold and less than or equal to the second threshold, the compressor's frequency increase rate is reduced; if the pipe temperature is greater than the second threshold and less than or equal to the third threshold, the compressor's frequency is limited; if the pipe temperature is greater than the third threshold and less than or equal to the fourth threshold, the compressor's frequency is reduced according to the first preset speed; if the pipe temperature is greater than the fourth threshold and less than or equal to the fifth threshold, the compressor's frequency is reduced according to the second preset speed; wherein, the second preset speed is greater than the first preset speed; if the pipe temperature is greater than the fifth threshold and less than or equal to the sixth threshold, the compressor is stopped.

[0097] When the refrigerant circulation in the heat exchanger unit is insufficient, the compressor discharge pressure is high, resulting in a high discharge temperature. In other words, when insufficient refrigerant circulation causes frosting, the indoor unit's pipe temperature is high when defrosting begins. Therefore, the temperature thresholds for various frequency adjustment operations should be increased accordingly. Thus, when control module 30 controls the compressor frequency based on the cause of frosting and the indoor unit's pipe temperature, the specific operations performed include: if the cause of frosting is determined to be insufficient refrigerant circulation, then determining the temperature range of the indoor unit's pipe temperature; if the pipe temperature is greater than the seventh threshold and less than or equal to the eighth threshold, then controlling the compressor's frequency increase rate to decrease; if the pipe temperature is greater than the eighth threshold... If the eighth threshold is less than or equal to the ninth threshold, the compressor frequency is limited. If the pipeline temperature is greater than the ninth threshold and less than or equal to the tenth threshold, the compressor frequency is reduced according to the first preset speed. If the pipeline temperature is greater than the tenth threshold and less than or equal to the eleventh threshold, the compressor frequency is reduced according to the second preset speed, where the second preset speed is greater than the first preset speed. If the pipeline temperature is greater than the eleventh threshold and less than or equal to the twelfth threshold, the compressor is stopped. Wherein, the seventh threshold is greater than the first threshold, the eighth threshold is greater than the second threshold, the ninth threshold is greater than the third threshold, the tenth threshold is greater than the fourth threshold, the eleventh threshold is greater than the fifth threshold, and the twelfth threshold is greater than the sixth threshold.

[0098] When the refrigerant circulation in the heat exchanger unit is insufficient, the following situations may prevent timely antifreeze or defrosting: The evaporator inlet temperature is below the freezing point, and frost begins to form at the evaporator inlet. Due to insufficient refrigerant circulation, after heat exchange with the air, the temperature in the middle of the evaporator is higher than or far above the freezing point of water. At this time, the temperature detected by the sensor located in the middle of the evaporator does not meet the conditions for antifreeze or defrosting action. As the unit operates, the frost at the evaporator inlet gradually thickens and spreads towards the evaporator outlet. At this time, the temperature in the middle of the evaporator will also gradually decrease. When the conditions for antifreeze or defrosting action are met, the antifreeze or defrosting action will be executed. Because a large amount of frost accumulates at the evaporator inlet, the frost on the evaporator cannot be completely melted after the antifreeze or defrosting action is executed. It will gradually accumulate during subsequent operation, leading to a rapid decrease in the heat exchange efficiency of the heat exchanger unit, frost clogging the drain outlet causing water leakage, and even system failure. Therefore, controlling the defrosting and defrosting stop points by setting sensors on the evaporator to detect temperature is inaccurate. Thus, this embodiment uses whether the pipe temperature and exhaust temperature continuously decrease as defrosting determination conditions to decide whether to perform defrosting. Therefore, the control module 30 is also used to: before starting the defrosting operation, determine whether the pipe temperature and exhaust temperature meet preset conditions; if yes, control the heat exchange unit to start the defrosting operation; if no, control the heat exchange unit to operate normally. The preset conditions include: the pipe temperature continuously decreases for a first preset time and always remains above 0°C; and the exhaust temperature continuously decreases for a second preset time.

[0099] Example 4

[0100] This embodiment provides a heat exchange unit, including the defrosting control device of the above embodiment, and applies the defrosting control method of the above embodiment to set different compressor frequency control strategies for two causes of frost: insufficient refrigerant circulation and compressor liquid return, which can achieve targeted defrosting and improve the defrosting effect.

[0101] Example 5

[0102] This embodiment provides an air conditioner, including the heat exchange unit of the above embodiment. The heat exchange unit includes the defrost control device of the above embodiment and applies the defrost control method of the above embodiment to set different compressor frequency control strategies for two causes of frost: insufficient refrigerant circulation and compressor liquid return. This enables targeted defrosting and improves the defrosting effect.

[0103] Example 6

[0104] This embodiment provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the defrosting control method of the above embodiment.

[0105] The device embodiments described above are merely illustrative. The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical modules; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0106] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0107] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A defrosting control method, characterized in that, The method includes: After the defrosting operation begins, obtain the compressor's discharge temperature; The cause of frosting is determined based on the exhaust temperature. The frequency of the compressor is controlled based on the cause of frost formation and the pipe temperature of the indoor unit. Determining the cause of frosting based on the exhaust temperature includes: Determine whether the exhaust temperature is lower than the preset temperature; If so, then the cause of the frosting is determined to be compressor liquid return; If not, then the cause of the frosting is determined to be insufficient refrigerant circulation.

2. The method according to claim 1, characterized in that, The compressor frequency is controlled based on the cause of frosting and the pipe temperature of the indoor unit, including: If the cause of the frosting is determined to be compressor liquid return, then determine the temperature range of the indoor unit's piping temperature. If the pipeline temperature is greater than a first threshold and less than or equal to a second threshold, the compressor's frequency ramp-up rate is reduced. If the pipeline temperature is greater than the second threshold and less than or equal to the third threshold, then the compressor frequency is limited. If the pipeline temperature is greater than the third threshold and less than or equal to the fourth threshold, the compressor is controlled to reduce its frequency according to the first preset speed. If the pipeline temperature is greater than the fourth threshold and less than or equal to the fifth threshold, the compressor is controlled to reduce its frequency at a second preset speed; wherein the second preset speed is greater than the first preset speed. If the pipeline temperature is greater than the fifth threshold and less than or equal to the sixth threshold, the compressor is controlled to stop.

3. The method according to claim 2, characterized in that, The compressor frequency is controlled based on the cause of frosting and the pipe temperature of the indoor unit, including: If the cause of the frosting is determined to be insufficient refrigerant circulation, then determine the temperature range of the indoor unit's piping temperature. If the pipeline temperature is greater than the seventh threshold and less than or equal to the eighth threshold, the compressor's frequency ramp-up rate is reduced. If the pipeline temperature is greater than the eighth threshold and less than or equal to the ninth threshold, then the compressor frequency is limited. If the pipeline temperature is greater than the ninth threshold and less than or equal to the tenth threshold, then the compressor is controlled to reduce its frequency according to the first preset speed. If the pipeline temperature is greater than the tenth threshold and less than or equal to the eleventh threshold, the compressor is controlled to reduce its frequency at a second preset speed; wherein the second preset speed is greater than the first preset speed. If the pipeline temperature is greater than the eleventh threshold and less than or equal to the twelfth threshold, then the compressor is controlled to stop. Wherein, the seventh threshold is greater than the first threshold, the eighth threshold is greater than the second threshold, the ninth threshold is greater than the third threshold, the tenth threshold is greater than the fourth threshold, the eleventh threshold is greater than the fifth threshold, and the twelfth threshold is greater than the sixth threshold.

4. The method according to claim 1, characterized in that, Before initiating the defrosting operation, the method further includes: Determine whether the pipeline temperature and the exhaust temperature meet preset conditions; If so, then control the heat exchange unit to start the defrosting operation; If not, then control the heat exchange unit to operate normally.

5. The method according to claim 4, characterized in that, The preset conditions include: The pipeline temperature continuously decreases for a first preset time period and remains above 0°C; and... The exhaust temperature continuously decreases for a second preset time.

6. A defrosting control device, characterized in that, The device includes: The parameter acquisition module is used to acquire the compressor's exhaust temperature after the defrosting operation begins. The determination module is used to determine the cause of frosting based on the exhaust temperature; The control module is used to control the frequency of the compressor based on the cause of frosting and the pipe temperature of the indoor unit; The determination module is specifically used for: Determine whether the exhaust temperature is lower than the preset temperature; If so, then the cause of the frosting is determined to be compressor liquid return; If not, then the cause of the frosting is determined to be insufficient refrigerant circulation.

7. A heat exchange unit, characterized in that, It includes the defrosting control device as described in claim 6, and applies the defrosting control method as described in any one of claims 1 to 5.

8. An air conditioner, characterized in that, Includes the heat exchange unit as described in claim 7.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the method as described in any one of claims 1 to 5.

Images