Heating control method for air conditioner

Abstract

The present application relates to the air conditioning technical field, specifically to a kind of heating control method of air conditioner.The present application aims to solve the problem of air conditioner in severe cold conditions, heating capacity attenuation, outdoor unit frost problem.For this purpose, the air conditioner of the present application includes that the compressor, indoor heat exchanger, first throttling device and outdoor heat exchanger are communicated by refrigerant pipeline, the compressor has air supplement port, and the air conditioner further includes air supplement pipeline, one end of air supplement pipeline is communicated with the inlet of first throttling device, the other end is communicated with air supplement port, second throttling device is arranged on air supplement pipeline, and the heating control method includes: obtaining the first coil temperature of outdoor heat exchanger during heating operation;The size of first coil temperature and preset temperature threshold is compared;Based on the comparison result, selectively air supplement is carried out for the compressor.The present application can effectively inhibit frost by air supplement, and ensure system heating capacity, improve system energy efficiency.

Description

Technical Field

[0001] This invention relates to the field of air conditioning technology, and more specifically to a heating control method for an air conditioner. Background Technology

[0002] In recent years, energy shortages and environmental pollution have become increasingly serious problems, becoming one of the main factors restricting social development. Traditional methods of providing heat through fuel combustion or electric heating have significant shortcomings in terms of energy utilization and environmental protection, and are gradually being replaced by more energy-efficient and environmentally friendly heat pump systems. Air source heat pumps are heat pump devices that use ambient air as a high-temperature (low-temperature) heat source to meet cooling (heating) needs. They have a simple structure, are easy to use, and are suitable for individual household installations, making them the main type of indoor air conditioner used in my country.

[0003] However, traditional air source heat pump systems are greatly affected by the ambient temperature. For example, in extreme climates such as severe cold, they will exhibit phenomena such as a gradual decrease in heating capacity, easy frosting of the outdoor unit, and unstable system operation, which limits the applicable scope of air source heat pump systems.

[0004] Accordingly, a new technical solution is needed in this field to solve the above problems. Summary of the Invention

[0005] To address at least one of the aforementioned problems in the prior art, namely, to solve the issues of reduced heating capacity and easy frosting of the outdoor unit in cold conditions, this application provides a heating control method for an air conditioner. The air conditioner includes a compressor, an indoor heat exchanger, a first throttling device, and an outdoor heat exchanger, all connected via refrigerant piping. The compressor has a refrigerant inlet, and the air conditioner further includes a refrigerant piping. One end of the refrigerant piping is connected to the inlet of the first throttling device, and the other end is connected to the refrigerant inlet. A second throttling device is installed on the refrigerant piping.

[0006] The heating control method includes:

[0007] During heating operation, the temperature of the first coil of the outdoor heat exchanger is obtained;

[0008] Compare the temperature of the first coil with the preset temperature threshold.

[0009] Based on the comparison results, the compressor is selectively replenished with gas.

[0010] In the preferred embodiment of the heating control method for the aforementioned air conditioner, the step of "selectively replenishing gas to the compressor based on the comparison results" further includes:

[0011] If the temperature of the first coil is less than or equal to the preset temperature threshold, then gas is supplied to the compressor.

[0012] In the preferred embodiment of the heating control method for the above-mentioned air conditioner, the step of "replenishing gas to the compressor" further includes:

[0013] Control the second throttling device to open to a preset degree.

[0014] In a preferred embodiment of the heating control method for the aforementioned air conditioner, after the step of "controlling the second throttling device to open to a preset degree", the heating control method further includes:

[0015] The temperatures of multiple second coils of the outdoor heat exchanger are obtained, and the rate of temperature change between the subsequent second coil temperature and the previous second coil temperature is calculated.

[0016] Determine the magnitude of the temperature change rate compared to a preset change rate threshold;

[0017] Based on the comparison results, the opening degree of the second throttling device is controlled.

[0018] In the preferred embodiment of the heating control method for the above-mentioned air conditioner, the step of "controlling the opening degree of the second throttling device based on the comparison result" further includes:

[0019] If the temperature change rate is greater than or equal to the preset change rate threshold, the second throttling device is controlled to maintain its current opening until the coil temperature of the outdoor heat exchanger is greater than the preset temperature threshold.

[0020] In the preferred embodiment of the heating control method for the above-mentioned air conditioner, the step of "controlling the opening degree of the second throttling device based on the comparison result" further includes:

[0021] If the temperature change rate is less than the preset change rate threshold, the opening of the second throttling device is increased until the coil temperature of the outdoor heat exchanger is greater than the preset temperature threshold.

[0022] In the preferred embodiment of the heating control method for the above-mentioned air conditioner, the step of "controlling the opening degree of the second throttling device to increase" further includes:

[0023] The opening degree of the second throttling device is increased as follows:

[0024] B + B × (Tpn-1 / Tpn)

[0025] Wherein, B is the current opening degree of the second throttling device; Tpn-1 is the prior second coil temperature; and Tpn is the subsequent second coil temperature.

[0026] In the preferred embodiment of the heating control method for the above-mentioned air conditioner, the preset temperature threshold is determined based on the outdoor ambient temperature.

[0027] In the preferred embodiment of the heating control method for the aforementioned air conditioner, the step of "determining the preset temperature threshold based on the outdoor ambient temperature" further includes:

[0028] Calculate the dew point temperature based on the outdoor ambient temperature.

[0029] The preset temperature threshold is determined based on the temperature range of the dew point temperature and the outdoor ambient temperature.

[0030] In the preferred embodiment of the heating control method for the aforementioned air conditioner, the step of "determining the preset temperature threshold based on the temperature range of the dew point temperature and the outdoor ambient temperature" further includes:

[0031] The preset temperature threshold is determined using the following formula:

[0032] Ty = Tes + a

[0033] Where Ty is the preset temperature threshold; Tes is the dew point temperature; and a is a correction coefficient, which is determined based on the temperature range of the outdoor ambient temperature.

[0034] The technical solution of this application, by setting up a gas supply pipeline and installing a second throttling device on the gas supply pipeline, can guide part of the refrigerant back to the compressor when the temperature of the first coil of the outdoor heat exchanger is too low, that is, when the outdoor heat exchanger is prone to frosting or has already frosted, by performing a gas supply operation on the compressor, thereby reducing the refrigerant flow in the outdoor heat exchanger, suppressing frosting, and also using gas supply to increase the compressor's suction temperature, thereby increasing the system's enthalpy value, broadening the applicability of the air conditioner in low-temperature environments, ensuring that the system's heating capacity does not decrease, improving system energy efficiency, and solving the problem of unstable compressor operation. Attached Figure Description

[0035] The present application will now be described with reference to the accompanying drawings. In the drawings:

[0036] Figure 1 This is a system diagram of the air conditioner of this application;

[0037] Figure 2 This is a flowchart of the heating control method for the air conditioner according to this application;

[0038] Figure 3 This is a logic diagram of one possible implementation of the heating control method for the air conditioner of this application.

[0039] List of reference numerals

[0040] 1. Compressor; 11. Gas inlet; 2. Four-way valve; 3. Outdoor heat exchanger; 31. Main heat exchange pipe section; 32. Auxiliary heat exchange pipe section; 4. First throttling device; 5. Indoor heat exchanger; 6. Second throttling device; 7. Gas inlet pipe; 8. Temperature sensor; 9. Refrigerant pipe. Detailed Implementation

[0041] Preferred embodiments of this application are described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of this application and are not intended to limit the scope of protection of this application. For example, although the indoor heat exchanger in the drawings is described in conjunction with parallel internal and external exhaust pipes, this arrangement is not fixed and can be adjusted as needed to adapt to specific applications. For instance, the indoor heat exchanger may include only internal or external exhaust heat exchange pipes, or the internal and external exhaust pipes may be connected in series.

[0042] It should be noted that in the description of this application, terms such as "left" and "right," indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. These are used merely for ease of description and do not indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Additionally, in the description of this application, "a plurality of" refers to at least two.

[0043] Furthermore, it should be noted that, in the description of this application, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" 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 direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0044] First refer to Figure 1 The present application describes the air conditioner. Among other things, Figure 1 This is a system diagram of the air conditioner of this application.

[0045] like Figure 1As shown, to address the issues of reduced heating capacity and easy frosting of the outdoor unit in cold conditions, the air conditioner of this application includes a compressor 1, a four-way valve 2, an indoor heat exchanger 5, a first throttling device 4, and an outdoor heat exchanger 3. The compressor 1, four-way valve 2, indoor heat exchanger 5, first throttling device 4, and outdoor heat exchanger 3 are sequentially connected via refrigerant piping 9 to form a heating cycle. The indoor heat exchanger 5 has an internal exhaust pipe and an external exhaust pipe, which are connected in parallel. The above connection method and heating working principle are conventional techniques in this field and will not be elaborated further in this application. Specifically, in this application, the compressor 1 is provided with a gas inlet 11, and the outdoor heat exchanger 3 includes a main heat exchange pipe section 31 and an auxiliary heat exchange pipe section 32. The main heat exchange pipe section 31 and the auxiliary heat exchange pipe section 32 are connected in parallel, with their inlets simultaneously connected to the first throttling device 4 and their outlets simultaneously connected to the four-way valve 2. The air conditioner also includes a gas supply pipe 7, one end of which is connected to the inlet of the first throttling device 4, and the other end is connected to the gas supply port 11. A second throttling device 6 is installed on the gas supply pipe 7. Preferably, the first throttling device 4 and the second throttling device 6 are electronic expansion valves. In addition, a temperature sensor 8 is installed on the main heat exchange pipe section 31 at the inlet of the outdoor heat exchanger 3. This temperature sensor 8 is used to detect the coil temperature of the outdoor heat exchanger 3.

[0046] During normal heating, the first throttling device 4 is open and the second throttling device 6 is closed. The refrigerant discharged from the compressor 1 enters the indoor heat exchanger 5 after passing through the four-way valve 2 to exchange heat with the indoor air. After heat exchange, the refrigerant flows out of the indoor heat exchanger 5 and into the first throttling device 4. After being throttled by the first throttling device 4, it enters the main heat exchange tube section 31 and the auxiliary heat exchange tube section 32 of the outdoor heat exchanger 3 to exchange heat with the outdoor air. Multiple heating circuits can reduce pressure drop loss. After heat exchange, the refrigerant flows out of the outdoor heat exchanger 3 and merges back to the compressor 1 through the four-way valve 2, completing the system cycle.

[0047] When the coil temperature of the outdoor heat exchanger 3 is too low during the heating process, the second throttle valve is opened, so that part of the refrigerant discharged from the indoor heat exchanger 5 continues to participate in the heating cycle through the outdoor heat exchanger 3, while the other part of the refrigerant enters the gas supply line 7, is throttled by the second throttle valve, and flows back to the gas supply port 11 of the compressor 1 along the gas supply line 7 to supply gas to the compressor 1, reduce the refrigerant flow of the outdoor heat exchanger 3, and increase the suction temperature of the compressor 1.

[0048] Those skilled in the art will understand that the above-described configuration of the air conditioner is merely a preferred embodiment. They can adjust the structure of the air conditioner without departing from the principles of this application, making it applicable to more specific application scenarios. For example, although the air conditioner is described in conjunction with the inclusion of a four-way valve 2, this implementation is not fixed. In other embodiments, those skilled in the art can selectively omit the four-way valve 2, making the air conditioner a heating-only unit. Furthermore, the specific forms of the first throttling device 4 and the second throttling device 6 are not limited in this application. The first throttling device 4 can also be a capillary tube or a thermal expansion valve, and the second throttling device 6 can also be other valves with adjustable opening. Similarly, although the outdoor heat exchanger 3 is described in conjunction with the inclusion of a main heat exchange pipe section 31 and an auxiliary heat exchange pipe section 32, the specific structural form of the outdoor heat exchanger 3 is not fixed. Those skilled in the art can replace it, such as including only the main heat exchange pipe section 31 and omitting the auxiliary heat exchange pipe section 32. Furthermore, the location of the temperature sensor 8 is not unique; it can be located at any position on the outdoor heat exchanger 3.

[0049] The following reference Figure 2 This paper introduces the heating control method of this application. Among other things, Figure 2 This is a flowchart of the heating control method for the air conditioner according to this application.

[0050] like Figure 2 As shown, corresponding to the aforementioned air conditioner, the heating control method of the air conditioner in this application includes:

[0051] S101. During heating operation, the temperature of the first coil of the outdoor heat exchanger is obtained. For example, the temperature of the first coil of the outdoor heat exchanger can be obtained through a temperature sensor on the outdoor heat exchanger.

[0052] S103. Compare the temperature of the first coil with the preset temperature threshold. For example, the preset temperature threshold is pre-set. This preset temperature threshold can be the temperature at which the outdoor heat exchanger will frost under the current ambient temperature, or it can be the dew point temperature corresponding to the current ambient temperature. This threshold is determined by empirical values, formulas, or experiments, etc. The specific determination method will be described in detail below. After obtaining the temperature of the first coil, the difference or ratio between the temperature of the first coil and the preset temperature threshold is calculated to compare their magnitudes.

[0053] S105. Based on the comparison results, selectively replenish gas to the compressor. For example, if the temperature of the first coil is less than or equal to the preset temperature threshold, it indicates that the temperature of the outdoor heat exchanger coil is too low, which will cause frost to form on the outdoor heat exchanger. In this case, gas replenishment can be performed on the compressor to reduce the refrigerant flow to the outdoor heat exchanger, thereby suppressing frost formation. Conversely, if the temperature of the first coil is greater than the preset temperature threshold, it indicates that the temperature of the outdoor heat exchanger coil is within the normal range. In this case, there is no need to replenish gas to the compressor; simply maintain the current operating state of the air conditioner.

[0054] The technical solution of this application, by setting up a gas supply pipeline and installing a second throttling device on the gas supply pipeline, can guide part of the refrigerant back to the compressor when the temperature of the first coil of the outdoor heat exchanger is too low, that is, when the outdoor heat exchanger is prone to frosting or has already frosted, by performing a gas supply operation on the compressor, thereby reducing the refrigerant flow in the outdoor heat exchanger, suppressing frosting, and also using gas supply to increase the compressor's suction temperature, thereby increasing the system's enthalpy value, broadening the applicability of the air conditioner in low-temperature environments, ensuring that the system's heating capacity does not decrease, improving system energy efficiency, and solving the problem of unstable compressor operation.

[0055] The preferred technical solution of this application is described below.

[0056] In one embodiment, the step of "selectively replenishing gas to the compressor based on the comparison results" further includes: if the temperature of the first coil is less than or equal to a preset temperature threshold, then replenishing gas to the compressor. Specifically, the step of "replenishing gas to the compressor" further includes: controlling the second throttling device to open to a preset opening degree. Preferably, the preset opening degree is the rated opening degree of the second throttling device, which can be preset at the factory by the electronic expansion valve or adjusted by the operator according to different air conditioner models. When the temperature of the first coil is less than or equal to the preset temperature threshold, controlling the second throttling device to open to the preset opening degree allows some refrigerant to flow back to the compressor through the gas replenishment pipeline, reducing the refrigerant flow in the outdoor heat exchanger and suppressing frost formation.

[0057] Of course, the above control method is merely a preferred option, and those skilled in the art can adjust it as long as it achieves gas replenishment to the compressor. For example, opening the second throttling device to its minimum opening degree, etc.

[0058] In one embodiment, after the step of "controlling the second throttling device to open to a preset opening degree", the heating control method further includes: acquiring multiple second coil temperatures of the outdoor heat exchanger and calculating the rate of temperature change between the subsequent second coil temperature and the previous second coil temperature; determining the magnitude of the rate of temperature change compared to a preset rate of change threshold; and controlling the opening degree of the second throttling device based on the comparison result. Specifically, if the rate of temperature change is greater than or equal to the preset rate of change threshold, the second throttling device is controlled to maintain its current opening degree until the coil temperature of the outdoor heat exchanger is greater than the preset temperature threshold. If the rate of temperature change is less than the preset rate of change threshold, the opening degree of the second throttling device is controlled to increase until the coil temperature of the outdoor heat exchanger is greater than the preset temperature threshold.

[0059] For example, after controlling the second throttling device to open to the rated opening, this application calculates the second coil temperature every 15 seconds, and starting from the second second coil temperature, calculates the temperature change rate between the subsequent second coil temperature and the previous second coil temperature, i.e., Tpn / Tpn-1, where Tpn is the subsequent second coil temperature and Tpn-1 is the previous second coil temperature. After calculating the temperature change rate, it is compared with a preset change rate threshold. In this application, the preset change rate threshold is taken as 1, i.e., whether Tpn / Tpn-1≥1 is true. If it is true, it proves that the coil temperature has increased or has not continued to decrease. At this time, the opening of the second throttling device has a frosting effect, and it is only necessary to maintain the current opening until the detected outdoor heat exchanger coil temperature is greater than the preset temperature threshold, and there is no risk of frosting.

[0060] Conversely, if Tpn / Tpn-1≥1 does not hold, it indicates that the outdoor coil temperature has further decreased, increasing the risk of frosting. In this case, it is necessary to further increase the opening of the second throttling device to allow more refrigerant to flow back to the compressor, further reducing the amount of refrigerant passing through the outdoor heat exchanger. Preferably, the step of "controlling the increase of the opening of the second throttling device" further includes: controlling the opening of the second throttling device to increase as follows:

[0061] B+B×(Tpn-1 / Tpn)(1)

[0062] Where B is the current opening degree of the second throttling device; Tpn-1 is the previous second coil temperature; and Tpn is the subsequent second coil temperature.

[0063] In other words, when adjusting the opening of the second throttling device, this application adapts the adjustment opening of the second throttling device to the current temperature change rate, thereby achieving rapid and precise adjustment of the gas supply while suppressing frost during heating dynamic gas replenishment.

[0064] Of course, the above control method is only a preferred option. Those skilled in the art can adjust the above implementation method so that this application can be applied to more specific application scenarios. In other implementation methods, for example, the above-mentioned step of adjusting the second throttling device can be omitted. For example, the opening degree of the second throttling device can also be adjusted by comparing the temperature of the second coil with that of the first coil, or by the difference between the temperature of the second coil after the second coil and that of the first coil. For example, the preset rate of change threshold can be any other possible value other than 1. This application only uses 1 as an example, and this value does not represent an improper limitation of this application. For example, the specific opening degree of the second throttling device can be continuously increased, or it can be increased after each judgment. In addition to using the above formula (1) to determine the increased opening degree, it can also be determined by increasing a fixed opening degree each time, or by using a comparison table between the increased opening degree and the ratio.

[0065] In one embodiment, the preset temperature threshold is determined based on the outdoor ambient temperature. Specifically, the step of "determining the preset temperature threshold based on the outdoor ambient temperature" further includes: calculating the dew point temperature based on the outdoor ambient temperature; and determining the preset temperature threshold based on the temperature range between the dew point temperature and the outdoor ambient temperature. Preferably, the step of "determining the preset temperature threshold based on the temperature range between the dew point temperature and the outdoor ambient temperature" further includes: determining the preset temperature threshold using the following formula:

[0066] Ty = Tes + a (2)

[0067] Where Ty is the preset temperature threshold; Tes is the dew point temperature; and a is the correction coefficient, which is determined based on the temperature range of the outdoor ambient temperature.

[0068] For example, the correction factor 'a' is determined as follows: when Tao ≥ 7℃, a = 0℃; when 7 ≤ Tao < -5℃, a = 3℃; when Tao < -5℃, a = 1℃.

[0069] In one embodiment, the dew point temperature is determined by the following formula:

[0070] Tes=C×Tao-b (3)

[0071] Where Tes is the dew point temperature; C is a coefficient; Tao is the outdoor ambient temperature; and b is a constant. One approach is to determine the value of C based on the outdoor ambient temperature after release: when Tao < 0℃, C = 0.8; when Tao ≥ 0℃, C = 0.6. In another implementation, b = 6.

[0072] Of course, the above values ​​are merely illustrative examples, and those skilled in the art can adjust them based on specific application scenarios.

[0073] By determining the dew point temperature based on the outdoor ambient temperature, and further determining the preset temperature threshold based on the outdoor ambient temperature and the dew point temperature, the accuracy of judging the frosting process can be improved, and the frosting status of the outdoor heat exchanger can be accurately judged.

[0074] Of course, the methods for determining the preset temperature threshold and the dew point temperature are not unique, and those skilled in the art can adjust them. For example, they can also be determined using fixed values, reference tables, empirical formulas, etc.

[0075] The following is combined with Figure 3 This paper will now describe one possible implementation of this application. Figure 3 This is a logic diagram of one possible implementation of the heating control method for the air conditioner of this application.

[0076] like Figure 3 As shown, in one possible operation:

[0077] S201, during heating operation, obtain the first coil temperature Tp of the outdoor heat exchanger and the outdoor ambient temperature Tao.

[0078] S202, based on the outdoor ambient temperature Tao, the dew point temperature Tes is determined using formula (3), and then the preset temperature threshold Tes+a is determined using formula (2).

[0079] S203, determine whether Tp≤Tes+a is true? If true, execute S204; otherwise, if false, execute S209.

[0080] S204, control the second throttling device to open to the rated opening, and then execute S205.

[0081] S205, acquire the temperature of the second coil every 15s, and calculate the ratio Tpn / Tpn-1 between the temperature of the second coil after the previous one and the temperature of the second coil before the previous one.

[0082] S206, Determine if Tpn / Tpn-1≥1 is true. If true, proceed to S207; otherwise, proceed to S208.

[0083] S207, control the second throttling device to maintain the current opening until Tp > Tes + a.

[0084] S208 controls the second throttling device to increase its opening degree, wherein the increase value is determined by formula (1).

[0085] S209, control the air conditioner to maintain its current operating state.

[0086] It should be noted that although the detailed steps of the method of this application have been described in detail above, those skilled in the art can combine, split and rearrange the above steps without departing from the basic principles of this application. Such modified technical solutions do not change the basic concept of this application and therefore fall within the protection scope of this application.

[0087] Those skilled in the art will understand that although some embodiments described herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this application and form different embodiments. For example, any of the claimed embodiments in the claims of this application can be used in any combination.

[0088] The technical solutions of this application have been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of this application is obviously not limited to these specific embodiments. Without departing from the principles of this application, 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 scope of protection of this application.

Claims

1. A heating control method of an air conditioner, characterized by, The air conditioner comprises a compressor, an indoor heat exchanger, a first throttling device and an outdoor heat exchanger which are communicated through refrigerant pipelines, and further comprises a charge pipeline which is communicated at one end with an inlet of the first throttling device and at the other end with a charge port of the compressor, and a second throttling device arranged on the charge pipeline, The heating control method comprises: During the heating operation, a first coil temperature of the outdoor heat exchanger is acquired; The first coil temperature is compared with a preset temperature threshold; Based on the comparison result, the compressor is selectively charged; The step of "based on the comparison result, the compressor is selectively charged" further comprises: If the first coil temperature is less than or equal to the preset temperature threshold, the compressor is charged, and the second throttling device is controlled to open to a preset opening degree; After the step of "the second throttling device is controlled to open to a preset opening degree", the heating control method further comprises: A plurality of second coil temperatures of the outdoor heat exchanger are acquired, and a temperature change rate between a latter second coil temperature and an earlier second coil temperature is calculated; The temperature change rate is compared with a preset change rate threshold; If the temperature change rate is less than the preset change rate threshold, the opening degree of the second throttling device is increased until the coil temperature of the outdoor heat exchanger is greater than the preset temperature threshold; The opening degree of the second throttling device is increased as follows: B+B×(Tpn-1 / Tpn) Wherein, B is the current opening degree of the second throttling device; Tpn-1 is the earlier second coil temperature; Tpn is the latter second coil temperature.

2. The heating control method of the air conditioner according to claim 1, wherein The step of "based on the comparison result, the opening degree of the second throttling device is controlled" further comprises: If the temperature change rate is greater than or equal to the preset change rate threshold, the current opening degree of the second throttling device is maintained until the coil temperature of the outdoor heat exchanger is greater than the preset temperature threshold.

3. The method of claim 1, wherein the step of determining the heating capacity of the air conditioner is performed by using a heating capacity map. The preset temperature threshold is determined based on an outdoor environment temperature.

4. The heating control method of the air conditioner according to claim 3, wherein The step of "the preset temperature threshold is determined based on an outdoor environment temperature" further comprises: Based on the outdoor environment temperature, a dew point temperature is calculated; Based on the dew point temperature and a temperature interval in which the outdoor environment temperature is located, the preset temperature threshold is determined.

5. The heating control method for an air conditioner according to claim 4, characterized in that, The step of "based on the dew point temperature and the temperature interval in which the outdoor environment temperature is located, the preset temperature threshold is determined" further comprises: The preset temperature threshold is determined by the following formula: Ty=Tes+a Wherein, Ty is the preset temperature threshold; Tes is the dew point temperature; a is a correction coefficient, and a is determined based on the temperature interval in which the outdoor environment temperature is located.

Images