Air conditioning unit

Abstract

The invention discloses an air conditioning unit which comprises an outdoor unit which comprises a compressor, an outdoor heat exchanger and an outdoor fan. The indoor unit comprises an indoor heat exchanger and an indoor fan; the controller is configured to obtain a current unit mode and a duration threshold value and a temperature threshold value corresponding to the current unit mode; the operation duration of the air conditioning unit and the coil pipe temperature of the outdoor heat exchanger are obtained; and when the operation duration reaches the duration threshold value and the coil pipe temperature of the outdoor heat exchanger does not exceed the temperature threshold value, it is judged that the defrosting entering condition is met. According to the air conditioning unit, when the operation duration of the air conditioning unit reaches the duration threshold value corresponding to the current unit mode and the coil pipe temperature of the outdoor heat exchanger is smaller than or equal to the temperature threshold value corresponding to the current unit mode, it is judged that the defrosting entering condition is met; the unit mode, the operation duration of the air conditioning unit and the coil temperature of the outdoor heat exchanger are comprehensively considered, the defrosting entering condition is accurately judged, and the technical problem that in the prior art, the defrosting entering condition is not accurate is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioning, in particular to an air conditioning unit. Background Art

[0002] As people's living standards continue to improve, installing air-conditioning units in homes, hotels and other places to improve environmental comfort has become an important choice for people to improve their comfort needs.

[0003] Whether the air-conditioning unit can accurately enter the defrost mode is also an important criterion for measuring the performance of the air-conditioning unit.

[0004] At present, most manufacturers only perform the most basic sensor temperature judgment on whether the unit has entered defrost mode, and do not perform targeted temperature control based on different temperature characteristics.

[0005] The existing air conditioner cannot judge the optimal entry condition according to the change of external environment temperature or local temperature characteristics before entering the defrosting mode. The current air conditioner cannot judge the entry condition of defrosting accurately. Summary of the invention

[0006] The invention provides an air conditioning unit, which solves the technical problem of inaccurate defrosting entry conditions in the prior art.

[0007] In order to achieve the above object, the present invention adopts the following technical scheme:

[0008] The present invention provides an air conditioning unit, comprising:

[0009] An outdoor unit, which includes a compressor, an outdoor heat exchanger, and an outdoor fan;

[0010] An indoor unit, which includes an indoor heat exchanger and an indoor fan;

[0011] A controller, which is configured to: obtain a current unit mode and a duration threshold and a temperature threshold corresponding to the current unit mode; obtain the operating time of the air-conditioning unit and the coil temperature of the outdoor heat exchanger; when the operating time reaches the duration threshold and the coil temperature of the outdoor heat exchanger does not exceed the temperature threshold, determine that the defrost entry conditions are met.

[0012] In some embodiments of the present application, the controller is further configured to:

[0013] The correspondence between the preset unit mode and the duration threshold;

[0014] According to the current unit mode, the corresponding relationship is queried to obtain the duration threshold corresponding to the current unit mode.

[0015] In some embodiments of the present application, the controller is further configured to:

[0016] Get the temperature threshold calculation formula corresponding to the current unit mode:

[0017] When the current unit mode is the standard area mode, the corresponding temperature threshold is Min (A, B, C);

[0018] When the current unit mode is the cold region mode, the corresponding temperature threshold is Min (A, B);

[0019] When the current unit mode is the temperature zone mode, the corresponding temperature threshold is Min (A, B, C);

[0020] Get the outdoor ambient temperature Ta, calculate the values ​​of A, B, and C respectively, and get the corresponding temperature threshold:

[0021] A=a+KtV;

[0022] B = d(b1×Ta-b2)-b3+Ktv;

[0023] C=d(c1×Ta-c2)-c3+KtV;

[0024] Among them, a, b1, b2, b3, c1, c2, c3, and Ktv are all constants, and their sizes correspond to the unit mode; d is a constant coefficient greater than 0.

[0025] In some embodiments of the present application, the controller is further configured to:

[0026] The correspondence between the preset unit mode and the size of a, b1, b2, b3, c1, c2, c3;

[0027] According to the current unit mode, the corresponding relationship is queried to obtain the sizes of a, b1, b2, b3, c1, c2, and c3 corresponding to the current unit mode.

[0028] In some embodiments of the present application, the controller is further configured to:

[0029] The corresponding relationship between the preset unit mode, the presence or absence of air supplement and enthalpy increase, and the size of a, b1, b2, b3, c1, c2, and c3;

[0030] According to the current unit mode and whether there is air supplement to increase enthalpy, the corresponding relationship is queried to obtain the corresponding values ​​of a, b1, b2, b3, c1, c2, and c3.

[0031] In some embodiments of the present application, the corresponding relationship between the unit mode and Ktv is:

[0032] When the unit mode is standard area mode, Ktv>0;

[0033] When the unit mode is cold area mode or temperature area mode, Ktv=0.

[0034] In some embodiments of the present application, the controller is further configured to:

[0035] When the unit mode is the standard area mode, determine whether the outdoor fan is running and the air conditioning unit is in automatic operation mode;

[0036] If satisfied, then Ktv = k1;

[0037] If not satisfied, then Ktv = k2;

[0038] 0 <k2<k1。

[0039] In some embodiments of the present application, the controller is further configured to:

[0040] The preset values ​​of k1 and k2 are used to calculate A, B and C respectively;

[0041] When the unit mode is the standard area mode, when calculating A, B, and C, the sizes of k1 and k2 are obtained.

[0042] In some embodiments of the present application, the controller is further configured to:

[0043] When the air replenishment enthalpy increase is preset, it is used to calculate the values ​​of k1 and k2 at A, B, and C respectively;

[0044] When there is no air supplementation to increase enthalpy, the values ​​of k1 and k2 are used to calculate A, B, and C respectively;

[0045] When the unit mode is the standard area mode, when calculating A, B, and C, the sizes of k1 and k2 are obtained based on whether there is air supplementation to increase enthalpy.

[0046] In some embodiments of the present application, the controller is further configured to:

[0047] When the air replenishment enthalpy increase is preset, it is used to calculate the values ​​of k1 and k2 at A, B, and C respectively;

[0048] When there is no air supplementation enthalpy increase and a low pressure sensor is preset, it is used to calculate the size of k1 and k2 at A, B, and C respectively;

[0049] When there is no air replenishment enthalpy increase and no low pressure sensor, it is used to calculate the size of k1 and k2 at A, B and C respectively;

[0050] When the unit mode is the standard area mode, when calculating A, B, and C, the sizes of k1 and k2 are obtained based on whether there is air replenishment to increase enthalpy and whether there is a low-pressure pressure sensor.

[0051] The technical solution of the present invention has the following technical effects relative to the prior art: the air-conditioning unit of the present invention obtains the current unit mode and the duration threshold and temperature threshold corresponding to the current unit mode; obtains the operating time of the air-conditioning unit and the coil temperature of the outdoor heat exchanger; when the operating time of the air-conditioning unit reaches the duration threshold and the coil temperature of the outdoor heat exchanger does not exceed the temperature threshold, it is determined that the defrost entry condition is met. Therefore, the air-conditioning unit of this embodiment determines the corresponding duration threshold and temperature threshold according to the current unit mode, and then compares the operating time of the air-conditioning unit with the duration threshold, and the coil temperature of the outdoor heat exchanger with the temperature threshold. When the operating time of the air-conditioning unit reaches the duration threshold corresponding to the current unit mode, and the coil temperature of the outdoor heat exchanger is less than or equal to the temperature threshold corresponding to the current unit mode, it is determined that the defrost entry condition is met; the unit mode, the operating time of the air-conditioning unit, and the coil temperature of the outdoor heat exchanger are comprehensively considered to accurately judge the defrost entry condition, improve the judgment accuracy of the defrost entry condition, and solve the technical problem of inaccurate defrost entry condition in the prior art.

[0052] After reading the specific embodiments of the present invention in conjunction with the accompanying drawings, other features and advantages of the present invention will become more clear. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0054] Figure 1 A flowchart of an embodiment of the steps executed by the controller of the air conditioning unit of the present invention;

[0055] Figure 2 A flowchart of another embodiment of the steps executed by the controller of the air conditioning unit of the present invention;

[0056] Figure 3 A flowchart of another embodiment of the steps executed by the controller of the air conditioning unit of the present invention;

[0057] Figure 4 A flowchart of another embodiment of the steps executed by the controller of the air conditioning unit of the present invention;

[0058] Figure 5 A flowchart of another embodiment of the steps executed by the controller of the air conditioning unit of the present invention;

[0059] Figure 6 A flowchart of another embodiment of the steps executed by the controller of the air conditioning unit of the present invention;

[0060] Figure 7 A flowchart of another embodiment of the steps executed by the controller of the air conditioning unit of the present invention;

[0061] Figure 8 A flowchart of another embodiment of the steps executed by the controller of the air conditioning unit of the present invention;

[0062] Fig. 9 A flowchart of another embodiment of the steps executed by the controller of the air conditioning unit of the present invention;

[0063] Fig.10 The present invention is a flowchart of another embodiment of the steps executed by the controller of the air conditioning unit. DETAILED DESCRIPTION

[0064] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0065] In the description of the present application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0066] The terms "first", "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0067] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0068] In the present invention, unless otherwise clearly stipulated and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0069] The disclosure below provides many different embodiments or examples to realize different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplicity and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides various specific examples of processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0070] The air conditioning unit performs the refrigeration cycle and heating cycle of the air conditioning unit by using a compressor, condenser, expansion valve and evaporator, and the controller performs control to realize the flow control of the refrigerant and the opening control of the expansion valve, etc. The refrigeration cycle and heating cycle include a series of processes involving compression, condensation, expansion and evaporation, and supply refrigerant to the air that has been conditioned and heat exchanged.

[0071] The compressor compresses the refrigerant gas in a high temperature and high pressure state and discharges the compressed refrigerant gas. The discharged refrigerant gas flows into the condenser. The condenser condenses the compressed refrigerant into a liquid phase, and the heat is released to the surrounding environment through the condensation process.

[0072] The expansion valve expands the high-temperature and high-pressure liquid refrigerant condensed in the condenser into a low-pressure liquid refrigerant. The evaporator evaporates the refrigerant expanded in the expansion valve and returns the refrigerant gas in a low-temperature and low-pressure state to the compressor. The evaporator can achieve a refrigeration effect by utilizing the latent heat of evaporation of the refrigerant to exchange heat with the material to be cooled. In the entire cycle, the air conditioning unit can adjust the temperature of the indoor space.

[0073] The air conditioner outdoor unit refers to a portion of a refrigeration cycle including a compressor and an outdoor heat exchanger, the air conditioner indoor unit includes an indoor heat exchanger, and an expansion valve may be provided in the air conditioner outdoor unit or the indoor unit.

[0074] The indoor heat exchanger and the outdoor heat exchanger function as a condenser or an evaporator. When the indoor heat exchanger functions as a condenser, the air conditioning unit functions as a heater in a heating mode, and when the indoor heat exchanger functions as an evaporator, the air conditioning unit functions as a cooler in a cooling mode.

[0075] The air conditioning unit of this embodiment includes an outdoor unit, an indoor unit, a controller, etc.

[0076] The outdoor unit includes a compressor, an outdoor heat exchanger, an outdoor fan, etc.

[0077] The indoor unit includes an indoor heat exchanger, an indoor fan, etc.

[0078] Controller, which controls the operation of the entire air conditioning unit.

[0079] The controller is configured to: obtain the current unit mode and the duration threshold and temperature threshold corresponding to the current unit mode; obtain the operating time of the air-conditioning unit and the coil temperature of the outdoor heat exchanger; when the operating time reaches the duration threshold and the coil temperature of the outdoor heat exchanger does not exceed the temperature threshold, determine that the defrost entry conditions are met.

[0080] When the outdoor ambient temperature is ≥ the set external temperature, the air conditioning unit can operate in heating mode; otherwise, the air conditioning unit cannot operate in heating mode. Different unit modes correspond to different set external temperatures. That is, different unit modes correspond to different set external temperatures.

[0081] For example, the unit modes include temperature region mode, standard region mode, and cold region mode.

[0082] In warm area mode, the air conditioner can only operate in heating mode when the outdoor ambient temperature is ≥ the first set external temperature (such as -5°C). When the outdoor ambient temperature is < the first set external temperature, the air conditioner cannot operate in heating mode.

[0083] In the standard area mode, the air conditioner can only operate in heating mode when the outdoor ambient temperature is ≥ the second set external temperature (such as -10℃). When the outdoor ambient temperature is < the second set external temperature, the air conditioner cannot operate in heating mode.

[0084] In the cold region mode, the air conditioner can only operate in heating mode when the outdoor ambient temperature is ≥ the third set external temperature (such as -15°C). When the outdoor ambient temperature is < the third set external temperature, the air conditioner cannot operate in heating mode.

[0085] The first set outer ring temperature> the second set outer ring temperature> the third set outer ring temperature.

[0086] The air conditioner unit is provided with a mode selection switch for selecting the unit mode. The user can select the unit mode according to the region where he is located.

[0087] In some embodiments of the present application, the controller performs the following steps: Figure 1 described.

[0088] Step S11: Obtain the current unit mode.

[0089] Get the current unit mode according to the state of the mode selection switch.

[0090] Step S12: Obtain the duration threshold and temperature threshold corresponding to the current unit mode.

[0091] Step S13: Obtain the operating time of the air-conditioning unit and the coil temperature of the outdoor heat exchanger.

[0092] The operating time of the air conditioning unit refers to the cumulative operating time since the last defrost exit.

[0093] Step S14: Determine whether the operating time of the air-conditioning unit reaches a time threshold and the coil temperature of the outdoor heat exchanger does not exceed a temperature threshold.

[0094] If not satisfied, return to step S11.

[0095] If it is satisfied, that is, the operating time of the air-conditioning unit reaches the time threshold and the coil temperature of the outdoor heat exchanger is less than or equal to the temperature threshold, step S15 is executed: it is determined that the defrost entry condition is met; the controller controls the air-conditioning unit to enter the defrost mode.

[0096] The air-conditioning unit of this embodiment obtains the current unit mode and the duration threshold and temperature threshold corresponding to the current unit mode; obtains the operating time of the air-conditioning unit and the coil temperature of the outdoor heat exchanger; when the operating time of the air-conditioning unit reaches the duration threshold, and the coil temperature of the outdoor heat exchanger does not exceed the temperature threshold, it is determined that the defrost entry condition is met. Therefore, the air-conditioning unit of this embodiment determines the corresponding duration threshold and temperature threshold according to the current unit mode, and then compares the operating time of the air-conditioning unit with the duration threshold, and the coil temperature of the outdoor heat exchanger with the temperature threshold. When the operating time of the air-conditioning unit reaches the duration threshold corresponding to the current unit mode, and the coil temperature of the outdoor heat exchanger is less than or equal to the temperature threshold corresponding to the current unit mode, it is determined that the defrost entry condition is met; the unit mode, the operating time of the air-conditioning unit, and the coil temperature of the outdoor heat exchanger are comprehensively considered to accurately judge the defrost entry condition, thereby improving the accuracy of judging the defrost entry condition and solving the technical problem of inaccurate defrost entry condition in the prior art.

[0097] The air conditioning unit of this embodiment accurately determines whether the air conditioning unit meets the defrost entry conditions through multi-parameter calculation and judgment.

[0098] In some embodiments of the present application, the controller is further configured to perform the following steps: Figure 2shown.

[0099] Step S21: Preset the correspondence between the unit mode and the duration threshold.

[0100] Step S22: According to the current unit mode, query the corresponding relationship to obtain the duration threshold corresponding to the current unit mode.

[0101] By presetting the correspondence between the unit mode and the duration threshold, and then querying the correspondence, the duration threshold corresponding to the current unit mode can be directly obtained, which is simple, convenient and accurate.

[0102] For example, as shown in Table 1,

[0103] J=0, the unit mode is the standard area mode, and the duration threshold is W;

[0104] J=2, the unit mode is warm area mode, and the duration threshold is W;

[0105] When J=1 or 3 or 4, the unit mode is the cold region mode.

[0106] That is, the cold region mode is further divided into three levels:

[0107] When J=1, the duration threshold is X; the air conditioning unit can only operate in heating mode when the outdoor ambient temperature is ≥ the fifth set external ring temperature (eg, -12°C).

[0108] When J=3, the duration threshold is Y; when the outdoor ambient temperature is ≥ the fourth set external ring temperature (such as -13°C), the air conditioning unit can operate in heating mode.

[0109] When J=4, the duration threshold is Z. When the outdoor ambient temperature is ≥ the third set external temperature (eg, -15°C), the air conditioning unit can operate in heating mode.

[0110] The first set outer ring temperature>the second set outer ring temperature>the fifth set outer ring temperature>the fourth set outer ring temperature>the third set outer ring temperature.

[0111] Table 1

[0112] Unit mode selection t(min) J＝0、2 W J＝1 X J＝3 Y J＝4 Z

[0113] In some embodiments of the present application, the controller is further configured to perform the following steps: Figure 3 shown.

[0114] Step S31: Preset the correspondence between the unit mode and the temperature threshold calculation formula.

[0115] For example, a correspondence table of preset unit modes and temperature threshold calculation formulas is shown in Table 2. By querying Table 2, the temperature threshold calculation formula corresponding to the current unit mode can be obtained.

[0116] Table 2

[0117] Unit mode selection Temperature threshold Standard area (J=0) Min(A, B, C) Cold regions (J=1, 3, 4) Min(A, B) Warm regions (J=2) Min(A, B, C)

[0118] Step S32: query the corresponding relationship to obtain the temperature threshold calculation formula corresponding to the current unit mode.

[0119] When the current unit mode is the standard area mode, the corresponding temperature threshold is Min (A, B, C);

[0120] When the current unit mode is the cold region mode, the corresponding temperature threshold is Min (A, B);

[0121] When the current unit mode is the temperature zone mode, the corresponding temperature threshold is Min (A, B, C).

[0122] Step S33: Obtain the outdoor ambient temperature Ta, calculate the values ​​of A, B, and C respectively, compare the values ​​of A, B, and C, and obtain the temperature threshold corresponding to the current unit mode.

[0123] A=a+KtV;

[0124] B = d(b1×Ta-b2)-b3+Ktv;

[0125] C = d(c1×Ta-c2)-c3+Ktv;

[0126] Among them, a, b1, b2, b3, c1, c2, c3, and Ktv are all constants, and their sizes correspond to the unit mode; d is a constant coefficient greater than 0.

[0127] That is, d is a constant coefficient greater than 0. The sizes of a, b1, b2, b3, c1, c2, c3, and Ktv correspond to the unit mode.

[0128] By designing the above steps S31 to S33, the corresponding relationship between the unit mode and the temperature threshold calculation formula is first preset; then the temperature threshold calculation formula corresponding to the current unit mode is obtained by querying the corresponding relationship. Then the outdoor ambient temperature Ta is obtained, the size of a, b1, b2, b3, c1, c2, c3, Ktv corresponding to the current unit mode is obtained, the values ​​of A, B, C are calculated respectively, the sizes of A, B, C are compared, and the temperature threshold corresponding to the current unit mode is obtained.

[0129] Through the above design, the temperature threshold comprehensively considers the outdoor ambient temperature and the current unit mode, and a relatively accurate temperature threshold can be calculated, thereby improving the accuracy of judging the defrost entry conditions.

[0130] The air conditioning unit of this embodiment refines the conditions for entering defrosting under different outdoor ambient temperature conditions. According to different outdoor ambient temperatures, different calculation methods are used to determine whether the whole unit needs defrosting.

[0131] Of course, when the current unit mode is the cold region mode, it is only necessary to calculate the size of A and B, and use the smaller value as the temperature threshold of the cold region mode.

[0132] In some embodiments of the present application, the controller is further configured to perform the following steps: Figure 4 shown.

[0133] Step S41: Preset the corresponding relationship between the unit mode and the sizes of a, b1, b2, b3, c1, c2, and c3.

[0134] Step S42: According to the current unit mode, query the corresponding relationship to obtain the sizes of a, b1, b2, b3, c1, c2, and c3 corresponding to the current unit mode.

[0135] By presetting the correspondence between the unit mode and the sizes of a, b1, b2, b3, c1, c2, c3, and then querying the correspondence, the sizes of a, b1, b2, b3, c1, c2, c3 corresponding to the current unit mode can be directly obtained, which is simple, convenient and accurate.

[0136] For example, the correspondence table between the preset unit mode and a, b1, b2, b3, c1, c2, c3 is shown in Table 3. By querying Table 3, the sizes of a, b1, b2, b3, c1, c2, c3 corresponding to the current unit mode can be obtained.

[0137] Table 3

[0138] Unit mode selection a b1 b2 b3 c1 c2 c3 Standard area constant constant constant constant constant constant constant Cold Regions constant constant constant constant constant constant constant Warm regions constant constant constant constant constant constant constant

[0139] In some embodiments of the present application, the size of a decreases in the order of standard region mode, cold region mode, and temperature region mode.

[0140] In some embodiments of the present application, d=1 / 16. That is, the calculation formulas of A, B, and C are as follows:

[0141] A=a+Ktv;

[0142] B = 1 / 16 (b1 × Ta - b2) - b3 + Ktv;

[0143] C = 1 / 16 (c1×Ta-c2)-c3+Ktv.

[0144] Whether the air conditioning unit has the function of replenishing air and increasing enthalpy affects the size of a, b1, b2, b3, c1, c2, and c3, thereby affecting the size of the temperature threshold, and further affecting the defrost entry condition. Therefore, in some embodiments of the present application, the controller is further configured to perform the following steps, see Figure 5 shown.

[0145] Step S51: preset the corresponding relationship between the unit mode, the presence or absence of air supplement and enthalpy increase, and the sizes of a, b1, b2, b3, c1, c2, and c3.

[0146] Step S52: According to the current unit mode and whether there is air supplementation to increase enthalpy, query the corresponding relationship to obtain the corresponding values ​​of a, b1, b2, b3, c1, c2, and c3.

[0147] By presetting the correspondence between the unit mode, the presence or absence of air supplement and the sizes of a, b1, b2, b3, c1, c2, c3, and then querying the correspondence, the sizes of a, b1, b2, b3, c1, c2, c3 corresponding to the current unit mode and whether the unit has air supplement and heat increase can be directly obtained, which is simple, convenient and accurate.

[0148] For example, the corresponding table of preset unit mode, whether there is supplementary air enthalpy increase and a, b1, b2, b3, c1, c2, c3 is shown in Table 4. By querying Table 4, the values ​​of a, b1, b2, b3, c1, c2, c3 corresponding to the current unit mode and whether there is supplementary air enthalpy increase can be obtained.

[0149] Table 4

[0150]

[0151] In some embodiments of the present application, the corresponding relationship between the unit mode and Ktv is:

[0152] When the unit mode is standard area mode, Ktv>0;

[0153] When the unit mode is cold area mode or temperature area mode, Ktv=0.

[0154] Therefore, when the unit mode is cold region mode or warm region mode, the calculation formulas of A, B, and C are simplified. The calculation formulas of A, B, and C are:

[0155] A=a;

[0156] B = 1 / 16 (b1 × Ta - b2) - b3;

[0157] C = 1 / 16 (c1×Ta-c2)-c3.

[0158] In some embodiments of the present application, the controller is further configured to perform the following steps: Figure 6 shown.

[0159] Step S61: When the unit mode is the standard area mode, determine whether the outdoor fan is running and the air conditioning unit is in automatic operation mode.

[0160] If it is satisfied, that is, the outdoor fan is running and the air-conditioning unit is in automatic operation mode, step S62 is executed: Ktv=k1.

[0161] If it is not satisfied, that is, the outdoor fan is not running, or the air-conditioning unit is in manual operation mode, step S63 is executed: Ktv=k2.

[0162] Among them, 0 <k2<k1。

[0163] The air conditioning unit can be in manual operation mode or automatic operation mode (non-manual operation mode).

[0164] When the air-conditioning unit is in automatic operation mode, the compressor frequency, indoor fan speed, outdoor fan speed, electronic expansion valve opening, etc. are all automatically controlled.

[0165] When the air-conditioning unit is in manual operation mode, the compressor frequency, indoor fan speed, outdoor fan speed, electronic expansion valve opening, etc. are all manually controlled.

[0166] Therefore, in the standard area mode, if the outdoor fan is running and the air conditioner is in automatic operation mode, Ktv = k1. In the standard area mode, if the outdoor fan is not running, or the air conditioner is in manual operation mode, Ktv = k2; k1>k2. That is, the size of Ktv when the outdoor fan is running and the air conditioner is in automatic operation mode is greater than when the outdoor fan is not running or in manual operation mode. Different Ktv sizes are obtained according to different situations, thereby improving the accuracy of the temperature threshold.

[0167] In some embodiments of the present application, the controller is further configured to perform the following steps: Figure 7 shown.

[0168] Step S71: preset the sizes of k1 and k2 used for calculating A, B, and C respectively.

[0169] Step S72: When the unit mode is the standard area mode, when calculating A, B, and C, the sizes of k1 and k2 are obtained.

[0170] By presetting the sizes of k1 and k2 used to calculate A, B, and C, and then in standard area mode, when calculating A, B, and C, the size of k1 or k2 can be directly obtained, which is simple, convenient and accurate.

[0171] For example, a correspondence table between k1, k2 and A, B, and C is preset as shown in Table 5. By querying Table 5, the sizes of k1 and k2 when calculating A, B, and C in the standard region mode can be obtained.

[0172] Table 5

[0173]

[0174] Output parameter>0, that is, the outdoor fan is running.

[0175] Output parameter = 0, that is, the outdoor fan does not run.

[0176] Whether the air conditioning unit has the function of replenishing air and increasing enthalpy affects the values ​​of k1 and k2, thereby affecting the value of the temperature threshold, and further affecting the defrosting entry condition. Therefore, in some embodiments of the present application, the controller is further configured to perform the following steps, see Figure 8 shown.

[0177] Step S81: When there is a preset air supplement to increase enthalpy, it is used to calculate the sizes of k1 and k2 at A, B, and C respectively; when there is no preset air supplement to increase enthalpy, it is used to calculate the sizes of k1 and k2 at A, B, and C respectively.

[0178] Step S82: When the unit mode is the standard area mode, when calculating A, B, and C, the values ​​of k1 and k2 are obtained according to whether there is air supplementation and enthalpy increase.

[0179] By presetting the size of k1 and k2 when calculating A, B, and C when there is or is no air supplement to increase enthalpy, and then in the standard area mode, when calculating A, B, and C, the size of k1 or k2 can be directly obtained, which is simple, convenient and accurate.

[0180] For example, a corresponding table of k1, k2 and A, B, and C with or without air supplement and enthalpy increase is preset, as shown in Table 6. By querying Table 6, the values ​​of k1 and k2 used to calculate A, B, and C when there is air supplement and when there is no air supplement and enthalpy increase in the standard area mode can be obtained.

[0181] Table 6

[0182]

[0183] Whether there is a low pressure sensor on the return air pipe of the compressor affects the size of k1 and k2, thereby affecting the size of the temperature threshold, and further affecting the defrost entry condition. Therefore, in some embodiments of the present application, the controller is also configured to perform the following steps, see Fig. 9 shown.

[0184] Step S91: When the air replenishment enthalpy increase is preset, the values ​​of k1 and k2 are used to calculate A, B, and C respectively;

[0185] When there is no air supplementation enthalpy increase and a low pressure sensor is preset, it is used to calculate the size of k1 and k2 at A, B, and C respectively;

[0186] When there is no air supplementation enthalpy increase and no low-pressure pressure sensor, it is used to calculate the sizes of k1 and k2 at A, B, and C respectively.

[0187] Step S92: When the unit mode is the standard area mode, when calculating A, B, and C, the values ​​of k1 and k2 are obtained according to whether there is air replenishment to increase enthalpy and whether there is a low-pressure pressure sensor.

[0188] By presetting whether there is air supplementation to increase enthalpy and whether there is a low-pressure pressure sensor to calculate the size of k1 and k2 when calculating A, B, and C, and then in the standard area mode, when calculating A, B, and C, the size of k1 or k2 can be directly obtained, which is simple, convenient and accurate.

[0189] For example, a corresponding table of k1, k2 and A, B, and C when there is or is not air replenishment enthalpy increase, and when there is or is not a low-pressure pressure sensor is preset, as shown in Table 7. By querying Table 7, the size of k1 and k2 used to calculate A, B, and C when there is or is not air replenishment enthalpy increase, and when there is or is not a low-pressure pressure sensor in the standard area mode can be obtained.

[0190] Table 7

[0191]

[0192] Assume that the current unit mode is the standard regional mode, the air conditioning unit has no air supply and enthalpy increase function, the compressor return pipe has a low-pressure pressure sensor, the outdoor fan is running and the air conditioning unit is in automatic operation mode. The process of obtaining the temperature threshold is as follows, see Fig.10 shown.

[0193] Step S101: The current unit mode is obtained as the standard area mode, and by querying Table 2, the corresponding temperature threshold calculation formula is obtained as Min (A, B, C).

[0194] A=a+KtV;

[0195] B = 1 / 16 (b1 × Ta - b2) - b3 + Ktv;

[0196] C = 1 / 16 (c1×Ta-c2)-c3+Ktv.

[0197] Step S102: Obtain the outdoor ambient temperature Ta.

[0198] Step S103: by querying Table 4, the values ​​of a, b1, b2, b3, c1, c2 and c3 corresponding to the standard area mode without air supplementation and enthalpy increase are obtained.

[0199] Step S104: Since the outdoor fan is running and the air conditioning unit is in automatic operation mode, Ktv=k1.

[0200] By looking up Table 7, the values ​​of k1 used to calculate A, B, and C respectively when there is no supplementary air enthalpy increase and a low-pressure pressure sensor is provided.

[0201] Step S105: Calculate the values ​​of A, B, and C, and the minimum value thereof is the temperature threshold corresponding to the standard area mode.

[0202] In the description of the above embodiments, specific features, structures, materials or characteristics may be combined in a suitable manner in any one or more embodiments or examples.

[0203] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. An air conditioning unit, characterized in that: include: An outdoor unit, which includes a compressor, an outdoor heat exchanger, and an outdoor fan; An indoor unit, which includes an indoor heat exchanger and an indoor fan; A controller, which is configured to: obtain a current unit mode and a duration threshold and a temperature threshold corresponding to the current unit mode; obtain the operating time of the air-conditioning unit and the coil temperature of the outdoor heat exchanger; when the operating time reaches the duration threshold and the coil temperature of the outdoor heat exchanger does not exceed the temperature threshold, determine that the defrost entry conditions are met.

2. The air conditioning unit according to claim 1, characterized in that: The controller is also configured to: The correspondence between the preset unit mode and the duration threshold; According to the current unit mode, the corresponding relationship is queried to obtain the duration threshold corresponding to the current unit mode.

3. The air conditioning unit according to claim 1, characterized in that: The controller is also configured to: Get the temperature threshold calculation formula corresponding to the current unit mode: When the current unit mode is the standard area mode, the corresponding temperature threshold is Min (A, B, C); When the current unit mode is the cold region mode, the corresponding temperature threshold is Min (A, B); When the current unit mode is the temperature zone mode, the corresponding temperature threshold is Min (A, B, C); Get the outdoor ambient temperature Ta, calculate the values ​​of A, B, and C respectively, and get the corresponding temperature threshold: A=a+KtV; B = d(b1×Ta-b2)-b3+Ktv; C = d(c1×Ta-c2)-c3+Ktv; Among them, a, b1, b2, b3, c1, c2, c3, and Ktv are all constants, and their sizes correspond to the unit mode; d is a constant coefficient greater than 0.

4. The air conditioning unit according to claim 3, characterized in that: The controller is also configured to: The correspondence between the preset unit mode and the size of a, b1, b2, b3, c1, c2, c3; According to the current unit mode, the corresponding relationship is queried to obtain the sizes of a, b1, b2, b3, c1, c2, and c3 corresponding to the current unit mode.

5. The air conditioning unit according to claim 3, characterized in that: The controller is also configured to: The corresponding relationship between the preset unit mode, the presence or absence of air supplement and enthalpy increase, and the size of a, b1, b2, b3, c1, c2, and c3; According to the current unit mode and whether there is air supplement to increase enthalpy, the corresponding relationship is queried to obtain the corresponding values ​​of a, b1, b2, b3, c1, c2, and c3.

6. The air conditioning unit according to claim 3, characterized in that: The corresponding relationship between unit mode and Ktv is: When the unit mode is standard area mode, Ktv>0; When the unit mode is cold area mode or temperature area mode, Ktv=0.

7. The air conditioning unit according to claim 6, characterized in that: The controller is also configured to: When the unit mode is the standard area mode, determine whether the outdoor fan is running and the air conditioning unit is in automatic operation mode; If satisfied, then Ktv = k1; If not satisfied, then Ktv = k2; 0 <k2<k1。 8. The air conditioning unit according to claim 7, characterized in that: The controller is also configured to: The preset values ​​of k1 and k2 are used to calculate A, B and C respectively; When the unit mode is the standard area mode, when calculating A, B, and C, the sizes of k1 and k2 are obtained.

9. The air conditioning unit according to claim 7, characterized in that: The controller is also configured to: When the air replenishment enthalpy increase is preset, it is used to calculate the values ​​of k1 and k2 at A, B, and C respectively; When there is no air supplementation to increase enthalpy, the values ​​of k1 and k2 are used to calculate A, B, and C respectively; When the unit mode is the standard area mode, when calculating A, B, and C, the sizes of k1 and k2 are obtained based on whether there is air supplementation to increase enthalpy.

10. The air conditioning unit according to claim 7, characterized in that: The controller is also configured to: When the air replenishment enthalpy increase is preset, it is used to calculate the values ​​of k1 and k2 at A, B, and C respectively; When there is no air supplementation enthalpy increase and a low pressure sensor is preset, it is used to calculate the size of k1 and k2 at A, B, and C respectively; When there is no air replenishment enthalpy increase and no low pressure sensor, it is used to calculate the values ​​of k1 and k2 at A, B and C respectively; When the unit mode is the standard area mode, when calculating A, B, and C, the sizes of k1 and k2 are obtained based on whether there is air replenishment to increase enthalpy and whether there is a low-pressure pressure sensor.

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