A control method for preventing frost formation in air conditioners during heating and an air conditioner

Abstract

This invention provides a control method and air conditioner for preventing frost formation during air conditioning heating. The control method includes: S1, operating in heating mode; S2, acquiring outdoor temperature T, dew point temperature Td, and outdoor unit coil temperature Tw in real time; S3, determining whether T, Td, and Tw meet the frost formation conditions; if yes, maintaining the heating mode and turning on the outdoor heater; if no, maintaining the heating mode and turning off the outdoor heater, returning to step S2; the frost formation conditions are: T≤Td and Tw≤first preset temperature T1. This invention provides a control method and air conditioner for preventing frost formation during air conditioning heating, which can promptly heat and melt the frost on the outdoor heat exchanger, preventing frost buildup and ensuring the air conditioner maintains good heating performance. Furthermore, after meeting the frost formation conditions, this application does not switch the air conditioner from heating mode to defrost mode, but continues to operate in heating mode, fully ensuring the user's heating needs and guaranteeing user comfort.

Description

Technical Field

[0001] This invention relates to the field of air conditioning technology, and in particular to a control method and an air conditioner for preventing frost formation during air conditioning heating. Background Technology

[0002] Air conditioners are indispensable electrical appliances in people's daily lives and come in a variety of structural forms. With the continuous improvement of industrial design and the application of new technologies, materials, and shapes in air conditioners, not only have various types of air conditioners been developed, but the control technology of air conditioners has also been continuously optimized.

[0003] Taking air conditioning for heating in winter as an example, the outdoor unit of the air conditioner converts liquid refrigerant into gas during the heat exchange process. Due to the low outdoor temperature, when the temperature of the outdoor evaporator coil is lower than the freezing point of the air, water vapor in the air adheres to the surface of the outdoor evaporator to form a frost layer. The heat exchange effect and heating capacity gradually decrease, and the outlet air temperature is low, resulting in poor comfort.

[0004] Meanwhile, when existing technology detects that the outdoor evaporator surface may be frosted, the air conditioner will often switch from heating mode to defrosting mode. This not only fails to maintain the air conditioner's heating function, but may even result in "cold air blowing indoors," failing to meet users' heating needs and leading to poor comfort. Summary of the Invention

[0005] In view of this, the present invention aims to propose a control method and air conditioner for preventing frost formation during air conditioning heating, so as to solve the problem that the outdoor evaporator is prone to frost formation and the air conditioner has poor heating effect, resulting in poor user comfort in the prior art.

[0006] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0007] A control method for preventing air conditioner frost formation during heating includes: S1, the air conditioner operates in heating mode; S2, the air conditioner acquires the outdoor temperature T, dew point temperature Td, and outdoor unit coil temperature Tw in real time; S3, the air conditioner determines whether T, Td, and Tw meet the frost formation conditions; if yes, the air conditioner maintains the heating mode and turns on the outdoor heater; if no, the air conditioner maintains the heating mode and turns off the outdoor heater, returning to step S2; the frost formation conditions are: T≤Td and Tw≤a first preset temperature T1, where T1 is 0℃~2℃. By setting frost formation conditions, it is possible to determine whether the air conditioner is frosting in a timely and accurate manner; simultaneously, after the frost formation conditions are met, the air conditioner continues to operate in heating mode and promptly turns on the outdoor heater. On the one hand, this allows for timely heating and melting of the frost on the outdoor heat exchanger, preventing frost buildup and ensuring the air conditioner maintains good heating performance. On the other hand, this application does not switch the air conditioner from heating mode to defrost mode after the frost formation conditions are met, but instead maintains the heating mode to ensure the user's heating needs and comfort.

[0008] Furthermore, the process of obtaining the dew point temperature Td is as follows:

[0009] Detect outdoor temperature T and outdoor relative humidity RH; calculate using formula

[0010]

[0011] The dew point temperature Td is calculated and obtained, where a = 17 and b = 237, to improve the accuracy of the dew point temperature Td data, which to some extent helps to improve the control precision of the control method.

[0012] Furthermore, step S3 includes: S31, the air conditioner determines whether T, Td, and Tw meet the frosting conditions; if yes, the air conditioner maintains the heating mode and turns on the outdoor heater, proceeding to step S4; if no, the air conditioner maintains the heating mode and turns off the outdoor heater, returning to step S2; S4, the air conditioner determines whether Tw > the second preset temperature T2; if yes, the air conditioner controls the outdoor heater to operate at low power; if no, the air conditioner controls the outdoor heater to operate at high power, where T2 is -1℃ to -3℃; so that the corresponding outdoor heater power is adopted according to the different frosting rates under different conditions, while satisfying the heating and defrosting requirements, the power consumption of the electric heating element is minimized.

[0013] Furthermore, the control method includes: B1, the air conditioner operates in heating mode and obtains a set temperature A; B2, the air conditioner detects the indoor ambient temperature B in real time and calculates the difference ΔT between A and B; B3, the air conditioner determines whether ΔT < a first preset value K1; if yes, the air conditioner turns off the indoor heater and returns to step B2; if no, the air conditioner turns on the indoor heater. Step B3 includes: B31, the air conditioner determines whether ΔT < a first preset value K1; if yes, the air conditioner turns off the indoor heater and returns to step B2; if no, proceed to step B4; B4, the air conditioner determines whether the outdoor heater is on; if yes, the air conditioner turns on the indoor heater; if no, the air conditioner turns off the indoor heater and returns to step B2. By analyzing the set temperature and indoor ambient temperature, and using the "whether the outdoor heater is on" as the activation condition for the indoor heater, the indoor heater provides heat compensation to the indoor environment, which helps ensure the heating effect of the air conditioner and maintains the indoor ambient temperature within the range required by the user, thereby improving user comfort. On the other hand, the heat compensation of the indoor heater reduces the burden on the refrigerant to supply heat to the indoor environment (correspondingly, to a certain extent, the burden on the refrigerant to exchange heat with the outdoor environment is also reduced). At the same time, combined with the defrosting function of the outdoor heater, the combined effect of the two heaters can effectively reduce and suppress the degree of frost formation on the outdoor heat exchanger, ensuring good heating capacity of the air conditioner and fully guaranteeing user comfort.

[0014] Further, step B4 includes: B41, the air conditioner determines whether the outdoor heater is on; if yes, the air conditioner turns on the indoor heater and proceeds to step B5; if no, the air conditioner turns off the indoor heater and returns to step B2; B5, the air conditioner determines whether ΔT ≥ the second preset value K2; if yes, the air conditioner controls the indoor heater to operate at high power; if no, the air conditioner controls the indoor heater to operate at low power, where K1 is 0.5℃~1.5℃ and K2 is 2℃-3℃. Based on different indoor ambient temperatures, preset temperatures, and other data, the corresponding indoor heater power is adopted to minimize the power consumption of the electric heating element while meeting user comfort requirements.

[0015] An air conditioner employs the aforementioned control method for preventing frost formation during heating. The air conditioner includes an outdoor heat exchanger, an indoor heat exchanger, an outdoor heater, and an indoor heater. The outdoor heat exchanger and the indoor heat exchanger are connected via refrigerant piping. The outdoor heater is located at the inlet of the outdoor heat exchanger, and the indoor heater is located at the inlet of the indoor heat exchanger.

[0016] Compared with existing technologies, the control method and air conditioner for preventing frost formation during air conditioning heating described in this invention have the following advantages:

[0017] The present invention discloses a control method and air conditioner for preventing frost formation during air conditioning heating. Regarding the control process of the outdoor unit, by setting frost conditions, it can determine in a timely and accurate manner whether the air conditioner is frosting. Simultaneously, after the frost conditions are met, the air conditioner continues to operate in heating mode and promptly activates the outdoor heater. This not only heats and melts the frost on the outdoor heat exchanger in a timely manner, preventing frost buildup and ensuring the air conditioner maintains good heating performance, but also prevents the air conditioner from switching from heating mode to defrost mode after the frost conditions are met, thus ensuring the user's heating needs and comfort.

[0018] Regarding the control process of the indoor unit, the set temperature and indoor ambient temperature are analyzed, and the "whether the outdoor heater is on" is used as the starting condition for the indoor heater. On the one hand, the indoor heater provides heat compensation to the indoor environment, which helps to ensure the heating effect of the air conditioner and keep the indoor ambient temperature within the range required by the user, thereby improving user comfort. On the other hand, the heat compensation of the indoor heater reduces the burden on the refrigerant to supply heat to the indoor environment (correspondingly, to a certain extent, the burden on the refrigerant to exchange heat with the outdoor environment is also reduced). At the same time, combined with the defrosting function of the outdoor heater, the combined effect of the two heaters can effectively reduce and suppress the degree of frost on the outdoor heat exchanger, ensuring the air conditioner's good heating capacity and fully guaranteeing user comfort. Attached Figure Description

[0019] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0020] Figure 1 This is a flowchart illustrating the outdoor unit control process in a control method for preventing frost formation during air conditioning heating, as described in an embodiment of the present invention.

[0021] Figure 2 This is a flowchart illustrating the indoor unit control process in a control method for preventing frost formation during air conditioning heating, as described in an embodiment of the present invention.

[0022] Figure 3 This is a schematic diagram of an air conditioner according to an embodiment of the present invention. Detailed Implementation

[0023] The inventive concepts of this disclosure will be described below using terminology commonly used by those skilled in the art to communicate the essence of their work to others skilled in the art. However, these inventive concepts may be embodied in many different forms and should not be construed as limited to the embodiments described herein.

[0024] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0025] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0026] In existing technology, when an air conditioner is in heating mode and the temperature of the outdoor evaporator coil is lower than the freezing point of the air, water vapor in the air adheres to the surface of the outdoor evaporator, forming a frost layer. This gradually reduces the heat exchange effect and heating capacity, and the outlet air temperature is also low, resulting in poor comfort. Furthermore, when existing technology detects potential frost formation on the outdoor evaporator surface, the air conditioner often switches from heating mode to defrost mode. This not only fails to maintain the heating function but may even result in "cold air blowing indoors," failing to meet the user's heating needs and leading to poor comfort.

[0027] To address the problem in existing technologies where outdoor evaporators are prone to frosting, resulting in poor air conditioning heating performance and consequently, reduced user comfort, this embodiment proposes a control method to prevent air conditioning heating frosting, such as... Figure 1 As shown, the control method includes:

[0028] S1, Air conditioning heating mode;

[0029] The details regarding air conditioner heating modes and how to enter heating mode are the same as in existing technologies and will not be elaborated upon here.

[0030] S2. The air conditioner obtains the outdoor temperature T, dew point temperature Td, and outdoor unit coil temperature Tw in real time.

[0031] In this application, the process of obtaining the dew point temperature Td includes: detecting the outdoor temperature T and the outdoor relative humidity RH; and calculating the dew point temperature Td using the formula...

[0032]

[0033] The dew point temperature Td is calculated and obtained, where a = 17 and b = 237; this improves the accuracy of the dew point temperature Td data, which to some extent helps to improve the control precision of the control method.

[0034] The air conditioner detects and acquires the corresponding temperature (humidity) data by setting up a corresponding temperature (humidity) detector. Since it can directly adopt existing technology, it will not be elaborated on.

[0035] S3. The air conditioner determines whether the frosting conditions are met. If yes, the air conditioner maintains the heating mode and turns on the outdoor heater, proceeding to step S4. If no, the air conditioner maintains the heating mode and turns off the outdoor heater, returning to step S2.

[0036] The outdoor heater is installed at the refrigerant inlet of the outdoor unit to heat the refrigerant entering the evaporator of the outdoor unit. Preferably, the outdoor heater is an electromagnetic heating element.

[0037] The frosting conditions are: T≤Td and Tw≤first preset temperature T1.

[0038] It should be noted that the rated values ​​and preset values ​​involved in this application, such as T1, are preset data developed and designed by the air conditioner manufacturer before the air conditioner leaves the factory. In order to adapt to the user's own usage habits, at least some of the preset data can be adjusted by the user. Considering that there are often significant differences in the research and development concepts of different air conditioner manufacturers, air conditioner types, air conditioner performance, air conditioner operating environment, etc., the relevant preset data are not exactly the same. This application only provides a few reference data as examples, such as T1 being 0℃~2℃.

[0039] In this case, after the air conditioner is turned on for heating, if T > Td, there will be no condensation on the fins, meaning there will be no frost. Alternatively, if Tw > T1, even if there is condensation on the fins, it will not easily frost. Therefore, the air conditioner will continue to operate in heating mode and turn off the outdoor heater (or keep the outdoor heater off) to avoid unnecessary activation of the outdoor heater and minimize the power consumption of the electric heating element.

[0040] If T≤Td, it means that condensation will adhere to the fins. If Tw≤T1, the condensation will condense into solid ice crystals. As the air conditioner runs for a longer period of time, the outdoor heat exchanger will frost over. To prevent this, the air conditioner turns on the outdoor heater to heat the refrigerant entering the outdoor unit's evaporator, thereby increasing the surface temperature of the evaporator and preventing frost from forming on the outdoor unit. This allows the air conditioner to maintain a good heating performance, which is beneficial for ensuring user comfort.

[0041] S4. The air conditioner determines whether Tw > the second preset temperature T2; if yes, the air conditioner controls the outdoor heater to operate at low power; if no, the air conditioner controls the outdoor heater to operate at high power.

[0042] T2 is also a preset value. This application only provides a few reference values ​​as examples, such as T2 being -1℃ to -3℃. When the outdoor heater needs to be turned on, if Tw > T2, the frosting rate of the outdoor heat exchanger fins is relatively slow, and the outdoor heater only needs to use low power for heating. If Tw ≤ T2, the frosting rate of the outdoor heat exchanger fins is relatively fast. In order to avoid frosting and to avoid affecting the heating effect, the outdoor heater needs to be heated at low power.

[0043] The low power and high power are affected by the power adjustment level of different electric heating elements. This application does not limit them too much, but only uses some reference data as examples. For example, the low power of the outdoor heater is recorded as P1, and the high power of the outdoor heater is recorded as P2, where P2 = 2 * P1.

[0044] Therefore, steps S1-S4 of this application relate to the control of the outdoor unit. By setting frosting conditions, it is possible to determine in a timely and accurate manner whether the air conditioner is frosting. Simultaneously, after the frosting conditions are met, the air conditioner continues to operate in heating mode and promptly activates the outdoor heater. This serves two purposes: firstly, it heats and melts the frost on the outdoor heat exchanger in a timely manner, preventing frost buildup and ensuring the air conditioner maintains good heating performance; secondly, after the frosting conditions are met, this application does not switch the air conditioner from heating mode to defrosting mode, but continues to operate in heating mode to ensure the user's heating needs and comfort. Furthermore, this application uses corresponding outdoor heater power based on the different frosting rates under different conditions, minimizing the power consumption of the electric heating element while meeting the heating and defrosting requirements.

[0045] Furthermore, this application prioritizes the user's heating needs to fully ensure user comfort, which consequently involves adjusting the indoor environment. That is, such as... Figure 2 As shown, the control method of this application further includes:

[0046] B1. The air conditioner is set to heating mode and the set temperature A is obtained.

[0047] Correspondingly, the set temperature is consistent with the relevant content in the existing technology, which can be understood as the user setting the temperature, target temperature, etc.

[0048] B2. The air conditioner monitors the indoor ambient temperature B in real time and calculates the difference ΔT between A and B;

[0049] Where △T = AB.

[0050] B3. The air conditioner determines whether △T < the first preset value K1; if yes, the air conditioner turns off the indoor heater and returns to step B2; if no, proceed to step B4.

[0051] Wherein, K1 is a preset data. This application only provides a few reference data as examples, such as K1 being 0.5℃~1.5℃, preferably 1℃.

[0052] If △T < K1, it means that the indoor ambient temperature is close to the set temperature, or even has reached the set temperature, which can basically meet the user's comfort requirements. The air conditioner will continue to operate in heating mode and turn off the indoor heater (or keep the indoor heater off) to avoid unnecessary start-up of the indoor heater and minimize the power consumption of the electric heating element.

[0053] B4. The air conditioner determines whether the outdoor heater is on. If yes, the air conditioner turns on the indoor heater and proceeds to step B5. If no, the air conditioner turns off the indoor heater and returns to step B2.

[0054] B5. The air conditioner determines whether △T ≥ the second preset value K2; if yes, the air conditioner controls the indoor heater to operate at high power; if no, the air conditioner controls the indoor heater to operate at low power.

[0055] For step B4, if △T≥K1, it means that the indoor heater may need to be turned on.

[0056] Therefore, this application adds step B4, which uses "whether the outdoor heater is on" as the starting condition for the indoor heater. If the outdoor heater is not on, it may be because the air conditioner has just started running and the room is still in the heating stage. In this case, the indoor heater is turned off (or kept off) to avoid unnecessary start-up of the indoor heater and to minimize the power consumption of the electric heating element.

[0057] Conversely, if the outdoor heater is already on, it indicates that the air conditioner has been running in heating mode for a certain period of time, and there is a risk of frost formation outdoors. The low indoor temperature may also be due to the frost. Therefore, this application activates the indoor heater to heat the refrigerant entering the indoor heat exchanger, thereby increasing the temperature of the indoor coil and the indoor environment. This provides heat compensation for the indoor environment, which on the one hand helps ensure the heating effect of the air conditioner and keeps the indoor temperature within the range required by the user, thus improving user comfort. On the other hand, the heat compensation from the indoor heater reduces the burden on the refrigerant to supply heat indoors (correspondingly, to a certain extent, the burden on the refrigerant to exchange heat outdoors is also reduced). Combined with the defrosting effect of the outdoor heater, the combined effect of the two heaters can effectively reduce and suppress the degree of frost formation on the outdoor heat exchanger, ensuring good heating capacity of the air conditioner and fully guaranteeing user comfort.

[0058] In step B5, K2 is a preset data. This application only provides a few reference data as examples, such as K2 being 2℃-3℃, preferably 2℃. The low power and high power are affected by the power adjustment level of different electric heating elements. This application does not limit them too much, but only provides a few reference data as examples, such as the low power of the indoor heater being denoted as P3, and the high power of the indoor heater being denoted as P4, where P4 = 1.5 * P3.

[0059] Therefore, steps B1-B5 of this application are related to the control of the indoor unit. By analyzing the set temperature and the indoor ambient temperature, and taking "whether the outdoor heater is on" as the starting condition for the indoor heater, on the one hand, the indoor heater provides heat compensation to the indoor environment, which helps to ensure the heating effect of the air conditioner and keep the indoor ambient temperature within the range required by the user, thereby improving user comfort. On the other hand, the heat compensation of the indoor heater reduces the burden of refrigerant supplying heat to the indoor environment (correspondingly, to a certain extent, the burden of refrigerant exchanging heat to the outdoor environment is also reduced). At the same time, combined with the heating and defrosting function of the outdoor heater, the combined effect of the two heaters can effectively reduce and suppress the degree of frost on the outdoor heat exchanger, ensuring the good heating capacity of the air conditioner and fully guaranteeing user comfort.

[0060] Meanwhile, this application adopts the corresponding indoor heater power based on data such as different indoor ambient temperatures and preset temperatures, so as to minimize the power consumption of electric heating elements while meeting user comfort.

[0061] Furthermore, it should be noted that the outdoor unit control (steps S1-S5) and indoor unit control (steps B1-B5) in this application can operate independently and without interference, each functioning as a separate air conditioning control method. Alternatively, they can operate simultaneously within the same time period to prevent outdoor frost formation and ensure indoor user comfort. This approach balances the need for both outdoor frost prevention and comfortable indoor temperatures. For example, by activating both the outdoor heater and the indoor heater, the system can collaboratively address issues in existing technologies such as air conditioner frost formation, susceptibility to frost affecting heating capacity, poor heating performance, and low user comfort.

[0062] In this invention, any air conditioner may include the control method described in this embodiment, and based on the relevant control method provided in this embodiment, as shown in the appendix... Figure 3 As shown, the air conditioner also includes an outdoor heat exchanger (referred to as an "evaporator" in heating mode), an indoor heat exchanger (referred to as a "condenser" in heating mode), an outdoor heater, and an indoor heater. The outdoor heat exchanger and the indoor heat exchanger are connected via refrigerant piping. The outdoor heater is located at the inlet of the outdoor heat exchanger, and the indoor heater is located at the inlet of the indoor heat exchanger. Accordingly, both the outdoor heater and the indoor heater can use conventional electromagnetic heating elements.

[0063] In addition, the air conditioner also includes conventional air conditioner components such as fans, compressors, and capillary tubes, which are existing technologies and will not be described in detail here.

[0064] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A control method for preventing air conditioning from frosting during heating, characterized by, The control method comprises: S1, the air conditioner runs in a heating mode; S2, the air conditioner acquires outdoor temperature T, dew point temperature Td and outdoor unit coil temperature Tw in real time; S3, the air conditioner judges whether T, Td and Tw meet the frosting condition; if yes, the air conditioner keeps the heating mode and starts the outdoor heater; if no, the air conditioner keeps the heating mode and stops the outdoor heater, and returns to step S2; The frosting condition is T≤Td and Tw≤ first preset temperature T1; The control method comprises: B1, the air conditioner runs in a heating mode and acquires set temperature A; B2, the air conditioner detects indoor environment temperature B in real time and calculates the difference AT between A and B; B3, the air conditioner judges whether AT < first preset value K1; if yes, the air conditioner stops the indoor heater and returns to step B2; if no, the air conditioner starts the indoor heater; Step B3 comprises: B31, the air conditioner judges whether AT < first preset value K1; if yes, the air conditioner stops the indoor heater and returns to step B2; if no, step B4 is performed; B4, the air conditioner judges whether the outdoor heater is in a started state; if yes, the air conditioner starts the indoor heater; if no, the air conditioner stops the indoor heater and returns to step B2.

2. The control method for preventing heating frost formation of an air conditioner according to claim 1, wherein T1 is 0℃-2℃.

3. The control method of claim 1, wherein the control method comprises: The process of acquiring dew point temperature Td is: Outdoor temperature T and outdoor environment relative humidity RH are detected, and dew point temperature Td is acquired through calculation formula , , wherein a=17 and b=237.

4. The control method for preventing heating frost formation of an air conditioner according to claim 1, wherein Step S3 comprises: S31, the air conditioner judges whether T, Td and Tw meet the frosting condition; if yes, the air conditioner keeps the heating mode and starts the outdoor heater, and step S4 is performed; if no, the air conditioner keeps the heating mode and stops the outdoor heater, and returns to step S2; S4, the air conditioner judges whether Tw > second preset temperature T2; if yes, the air conditioner controls the outdoor heater to run in a small power state; if no, the air conditioner controls the outdoor heater to run in a large power state.

5. The control method of claim 4, wherein the control method comprises: T2 is -1℃--3℃.

6. The control method of claim 1, wherein the control method comprises: Step B4 comprises: B41, the air conditioner judges whether the outdoor heater is in a started state; if yes, the air conditioner starts the indoor heater, and step B5 is performed; if no, the air conditioner stops the indoor heater and returns to step B2; B5, the air conditioner judges whether AT ≥ second preset value K2; if yes, the air conditioner controls the indoor heater to run in a large power state; if no, the air conditioner controls the indoor heater to run in a small power state.

7. The control method of claim 1, wherein the control method comprises: determining whether the outdoor temperature is lower than a predetermined temperature; and if the outdoor temperature is lower than the predetermined temperature, controlling the air conditioner to operate in the heating operation mode. K1 is 0.5℃-1.5℃, and K2 is 2℃-3℃.

8. An air conditioner characterized by comprising: The air conditioner adopts the control method for preventing air conditioner heating frosting according to any one of claims 1-7, and comprises an outdoor heat exchanger, an indoor heat exchanger, an outdoor heater and an indoor heater; the outdoor heat exchanger and the indoor heat exchanger are communicated through a refrigerant pipeline; the outdoor heater is arranged at the inlet of the outdoor heat exchanger; and the indoor heater is arranged at the inlet of the indoor heat exchanger.

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