Multi-split air conditioner and defrosting control method thereof

Abstract

The invention provides a multi-split air conditioner and a defrosting control method thereof. The defrosting control method for the multi-split air conditioner comprises the steps that firstly, the number of outdoor units operating in the multi-split air conditioner is obtained, and a defrosting mode is determined according to the number of the outdoor units; then, if the defrosting mode is a second defrosting mode, determining a target group number; wherein the target group number is the group number corresponding to the maximum heating operation duration proportion of the outdoor unit; and finally, grouping the outdoor units based on the target group number, and controlling the outdoor units to alternately defrost according to each group. According to the control mode, the target group number is determined according to the heating operation duration proportion, the outdoor units are grouped according to the target group number, and the outdoor units are controlled to alternately defrost according to the groups, so that the heating operation duration of the outdoor units is guaranteed, and a multi-split air conditioner with a large number of outdoor units is avoided; due to the fact that the room temperature is reduced due to the fact that the heating operation duration of the outdoor unit is shortened, the air conditioner comfort level of a user is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioners, and more particularly to a multi-connected air conditioner and its defrosting control method. Background Art

[0002] For a multi-connected air conditioner (also known as a multi-split air conditioner unit), it usually includes multiple indoor units connected in parallel and one or more outdoor units. If there are multiple outdoor units, the multiple outdoor units are connected in parallel. In practical applications, in cold regions, multi-connected air conditioners are usually used for heating. Since the external air temperature is low, when the outdoor air exchanges heat with the coil of the outdoor heat exchanger, the moisture in the air is likely to adhere to the surface of the coil and frost forms. To ensure normal heating, the multi-connected air conditioner needs to defrost.

[0003] In traditional defrosting solutions, the heat required for defrosting often absorbs heat from the indoor unit, resulting in a decrease in room temperature and cold air flow, reducing the heating comfort of users. Based on this, in related technical solutions, usually multiple outdoor units connected to the same refrigerant circuit are divided into outdoor units for defrosting operation and outdoor units for heating operation, and the multiple outdoor units are controlled to defrost alternately in sequence; although this solution can ensure the heating comfort of users while defrosting, as the number of outdoor units in the multi-connected air conditioner increases, it not only causes the defrosting time of each outdoor unit to become shorter, but also increases the operation switching time between heating and defrosting of the outdoor units, thereby reducing the heating duration, which may lead to a decrease in room temperature and further reduce the air conditioning comfort of users. Therefore, how to optimize the defrosting of multiple outdoor units of a multi-connected air conditioner to ensure the air conditioning comfort of users is an urgent problem to be solved. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a multi-connected air conditioner and its defrosting control method, which alleviates the situation where the room temperature decreases due to the reduction of the heating operation duration of the outdoor units in a multi-connected air conditioner with a large number of outdoor units, thereby improving the air conditioning comfort of users.

[0005] In a first aspect, an embodiment of the present invention provides a defrosting control method for a multi-connected air conditioner. The multi-connected air conditioner includes at least one outdoor unit, and the method includes: obtaining the number of outdoor units running in the multi-connected air conditioner, and determining a defrosting mode according to the number; wherein, the defrosting mode includes a first defrosting mode and a second defrosting mode. The first defrosting mode is a mode in which the outdoor unit only performs defrosting operation, and the second defrosting mode is an alternative defrosting mode in which the outdoor unit performs defrosting and heating operations; if the defrosting mode is the second defrosting mode, determining the target number of groups; wherein, the target number of groups is the number of groups corresponding to the largest proportion of the heating operation duration of the outdoor unit; grouping the outdoor units based on the target number of groups, and controlling the outdoor units to defrost alternately according to each group.

[0006] The multi-line air conditioner defrosting control method provided by the embodiment of the present invention determines the target number of groups according to the heating operation duration ratio, groups the outdoor units according to the target number of groups, and controls the outdoor units to perform alternate defrosting according to each group, thereby avoiding the situation that the room temperature decreases due to the reduction of the heating operation duration of the outdoor units in a multi-line air conditioner with a large number of outdoor units, and further improving the air conditioner comfort of users.

[0007] Preferably, the step of grouping the outdoor units based on the target number of groups includes: obtaining the capacity of each outdoor unit, and first sequentially allocating the outdoor units to each group along the first direction in the order from largest to smallest according to the capacity; then, for the remaining outdoor units, continue to sequentially allocate them to each group along the second direction in the order from largest to smallest according to the capacity until the allocation of the outdoor units is completed; wherein, the first direction is the direction from the first group to the last group, and the second direction is the direction from the last group to the first group.

[0008] Preferably, after the step of grouping the outdoor units based on the target number of groups, the method further includes: obtaining the total capacity of the outdoor units in each group; if the total capacity of any group is greater than the sum of the total capacities of the remaining groups, perform an update process on the target number of groups, and re-group the outdoor units based on the updated target number of groups until the total capacity of any group is not greater than the sum of the total capacities of the remaining groups.

[0009] Preferably, before the step of re-grouping the outdoor units based on the updated target number of groups, the method further includes: determining whether the updated target number of groups is not greater than the number of units; if so, re-group the outdoor units based on the updated target number of groups.

[0010] Preferably, the method further includes: if the updated target number of groups is greater than the number of units, control the defrosting mode to switch from the second defrosting mode to the first defrosting mode, and control the outdoor units to operate according to the first defrosting mode.

[0011] Preferably, before the step of grouping the outdoor units based on the target number of groups, the method further includes: if the target number of groups is not greater than the number of units, group the outdoor units based on the target number of groups; or, if the target number of groups is greater than the number of units, first use the number of units as the target number of groups, and then group the outdoor units based on the target number of groups.

[0012] Preferably, the step of determining the target number of groups includes: obtaining the preset parameters of the outdoor units; wherein, the preset parameters include: heating duration, defrosting duration, operation switching duration, first coefficient, and second coefficient; calculating the target number of groups according to the preset parameters and the heating operation duration ratio;

[0013] Wherein, the expression of the heating operation duration ratio is as follows:

[0014]

[0015] Among them, P n represents the proportion of the heating operation duration, T h represents the heating continuous duration, T df represents the defrosting duration, T ch represents the operation switching duration, α represents the first coefficient, β represents the second coefficient, and n represents the target number of groups.

[0016] Preferably, the step of determining the defrosting mode according to the number of units includes: if the number of units is less than the preset number of units, determining the defrosting mode as the first defrosting mode; or, if the number of units is not less than the preset number of units, determining the defrosting mode as the second defrosting mode.

[0017] In a second aspect, an embodiment of the present invention further provides a multi-connected air conditioner, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the steps of the method in the first aspect are implemented.

[0018] In a third aspect, an embodiment of the present invention further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is run by a processor, the steps of the method in the first aspect are executed.

[0019] The embodiments of the present invention bring the following beneficial effects:

[0020] The embodiments of the present invention provide a multi-connected air conditioner and its defrosting control method. First, obtain the number of outdoor units running in the multi-connected air conditioner, and determine the defrosting mode according to the number of units; then, if the defrosting mode is the second defrosting mode, determine the target number of groups; among them, the target number of groups is the number of groups corresponding to the maximum proportion of the heating operation duration of the outdoor units; finally, group the outdoor units based on the target number of groups, and control the outdoor units to perform alternating defrosting according to each group. The above control method determines the target number of groups according to the proportion of the heating operation duration, and groups the outdoor units according to the target number of groups, so as to perform alternating defrosting according to each group, thereby ensuring the heating operation duration of the outdoor units, avoiding the situation that the room temperature decreases due to the reduction of the heating operation duration of the outdoor units in a multi-connected air conditioner with a large number of outdoor units, and further improving the air-conditioning comfort of users.

[0021] Other features and advantages of the present invention will be described in the following specification, and, in part, will be obvious from the specification, or will be understood by implementing the present invention. The objectives and other advantages of the present invention are achieved and obtained by the structures specifically pointed out in the specification and the drawings.

[0022] To make the above objectives, features, and advantages of the present invention more obvious and understandable, the following preferred embodiments are specifically described below in conjunction with the accompanying drawings. Description of the Drawings

[0023] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in related technologies, the following will briefly introduce the drawings required for use in the description of the specific embodiments or related technologies. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0024] Figure 1 It is a schematic diagram of the operation of a multi-connected air conditioner in the prior art solution;

[0025] Figure 2 It is a schematic diagram of an interval in the prior art solution;

[0026] Figure 3 It is a schematic diagram of another interval in the prior art solution;

[0027] Figure 4 It is a flowchart of a defrost control method for a multi-connected air conditioner provided by an embodiment of the present invention;

[0028] Figure 5 It is a schematic diagram of the corresponding relationship between the heating operation duration ratio P n and the number of groups n provided by an embodiment of the present invention;

[0029] Figure 6 It is a schematic diagram of the grouping result of the outdoor unit provided by an embodiment of the present invention;

[0030] Figure 7 It is another schematic diagram of the grouping result of the outdoor unit provided by an embodiment of the present invention;

[0031] Figure 8 It is another schematic diagram of the grouping result of the outdoor unit provided by an embodiment of the present invention;

[0032] Figure 9 It is a schematic diagram of the regrouping result of the outdoor unit provided by an embodiment of the present invention;

[0033] Figure 10 It is a flowchart of another defrost control method for a multi-connected air conditioner provided by an embodiment of the present invention;

[0034] Figure 11 It is a schematic diagram of an interval during defrosting of the grouped outdoor units provided by an embodiment of the present invention;

[0035] Figure 12 It is a schematic diagram of the structure of a multi-connected air conditioner provided by an embodiment of the present invention. Specific embodiments

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0037] For a multi-split air conditioner including multiple outdoor units, in order to alleviate the problem of reduced user heating comfort caused by defrosting operation, the related technical solutions usually divide multiple outdoor units connected to the same refrigerant circuit into outdoor units for defrosting operation and outdoor units for heating operation, and control the multiple outdoor units to perform alternating defrosting in sequence.

[0038] Taking two outdoor units as an example, the refrigerant flow process of alternating defrosting is described. As Figure 1 shown, the outdoor unit includes a first outdoor unit 11 and a second outdoor unit 12; among them, the first outdoor unit 11 includes a first compressor 111, a first four-way valve 112, a first heat exchanger 113, and a first electronic expansion valve 114; similarly, the second outdoor unit 12 includes a second compressor 121, a second four-way valve 122, a second heat exchanger 123, and a second electronic expansion valve 124. In addition, the multi-split air conditioner further includes three indoor units 21 connected in parallel, and each indoor unit 21 includes a third heat exchanger 213 and a third electronic expansion valve 214. It should be noted that the specific structure of the multi-split air conditioner can refer to the prior art, and the embodiments of the present invention will not be elaborated in detail here.

[0039] Specifically, when the first outdoor unit 11 is in heating operation and the second outdoor unit 12 is in defrosting operation; at this time, the refrigerant discharged from the first outdoor unit 11 is divided into two parts at point A, one part enters the second outdoor unit 12 through point B, and the other part enters the three indoor units 21 through point D respectively; in addition, after the refrigerant enters the second outdoor unit 12, it is compressed into a high-temperature and high-pressure refrigerant by the second compressor 121, and the high-temperature and high-pressure refrigerant enters the second heat exchanger 123 through the second four-way valve 122 and is used as the heat for defrosting, and then reaches point C through the second electronic expansion valve 124; and, the refrigerant flowing into the indoor unit 21 hardly undergoes heat exchange when passing through the third heat exchanger 213 in the indoor unit 21 because the refrigerant temperature (generally about 20 °C) is close to the room temperature, and reaches point E through the third electronic expansion valve 214, and finally the refrigerant at point C and the refrigerant at point E return to the first outdoor unit 11 through point F. In particular, in each indoor unit 21, in order to prevent cold air from being blown, the fans all stop working.

[0040] Therefore, in the traditional defrosting operation of the outdoor unit, the heat required for defrosting often absorbs heat from the indoor unit, resulting in a decrease in room temperature and cold air flow. Although the decrease in room temperature can be avoided by suppressing the heat exchange amount of the heat exchanger in the indoor unit, such as the third heat exchanger 213, the defrosting ability of the outdoor unit will be reduced. In the above alternating defrosting scheme, the heat exchanger of the outdoor unit performing the heating operation, such as the first heat exchanger 113, can absorb heat from the external air, which not only avoids the decrease in room temperature and cold air flow, but also ensures the defrosting ability, shortens the defrosting time, and improves the defrosting efficiency.

[0041] However, compared with the traditional defrosting scheme, the defrosting time for each time will be shortened in the above alternating defrosting scheme. As Figure 2 shown, the time duration from the start of the current defrosting operation of an outdoor unit to the start of the next defrosting operation is defined as an interval L. In the traditional defrosting scheme S0, an interval L includes the defrosting duration L1, the heating duration L2, and the operation switching duration L3 between defrosting and heating of the outdoor unit. In the alternating defrosting scheme S1 of two outdoor units, taking the first outdoor unit that first performs defrosting as an example, an interval L includes: the defrosting time L1, the heating duration L2, the operation switching duration L3 between defrosting and heating, and the indoor unit stop duration L4. Among them, in L4, the second outdoor unit performs heating. Therefore, compared with the traditional defrosting scheme, the defrosting time for each outdoor unit in the alternating defrosting scheme becomes shorter, and at the same time, the operation stop frequency of the indoor unit increases.

[0042] In addition, as the number of outdoor units increases, not only does the operation stop frequency of the indoor unit increase, but also the heating operation duration in an interval L decreases, which may lead to a decrease in room temperature. As Figure 3 shown, in an interval L, in the traditional defrosting scheme S0, in addition to the heating duration L2, it also includes a defrosting duration L1 and two operation switching durations L3. In the alternating defrosting scheme S1 of two outdoor units, in addition to the heating duration L2, it also includes two defrosting durations L1 and four operation switching durations L3. In the alternating defrosting scheme S2 of four outdoor units, in addition to the heating duration L2, it also includes four defrosting durations L1 and eight operation switching durations L3. Therefore, as the number of outdoor units in the multi-connected air conditioner increases, the operation switching duration will increase, thereby reducing the heating duration in an interval, and further may lead to a decrease in room temperature.

[0043] Based on this, the embodiments of the present invention provide a multi-connected air conditioner and its defrosting control method, which determine the target number of groups according to the proportion of the heating operation duration, group the outdoor units according to the target number of groups, and control the outdoor units to perform alternating defrosting according to each group, thereby ensuring the heating operation duration of the outdoor units, avoiding the situation that the room temperature decreases due to the reduction of the heating operation duration of the outdoor units in the multi-connected air conditioner with a large number of outdoor units, and further improving the air-conditioning comfort of users.

[0044] For the convenience of understanding this embodiment, the embodiments of the present invention will be introduced in detail below.

[0045] Embodiment 1

[0046] The embodiment of the present invention provides a defrosting control method for a multi-connected air conditioner; wherein, the multi-connected air conditioner includes at least one outdoor unit, as Figure 4 shown, the method includes the following steps:

[0047] Step S402, obtain the number of outdoor units running in the multi-connected air conditioner, and determine the defrosting mode according to the number.

[0048] Specifically, when the multi-connected air conditioner needs to defrost, first obtain the number of outdoor units running in the multi-connected air conditioner, and determine the defrosting mode according to the number; wherein, the defrosting mode includes a first defrosting mode and a second defrosting mode. The first defrosting mode is a mode in which the outdoor unit only performs defrosting operation, that is, in the first defrosting mode, the outdoor unit performs conventional defrosting operation; the second defrosting mode is an alternating defrosting mode in which the outdoor unit performs defrosting and heating operations, that is, in the second defrosting mode, the outdoor unit performs alternating operations of heating and defrosting.

[0049] Among them, determining the defrosting mode according to the number includes: if the number is less than the preset number, determining the defrosting mode as the first defrosting mode; or, if the number is not less than the preset number, determining the defrosting mode as the second defrosting mode. In practical applications, the preset number is 2 units. When the number is less than 2 units, that is, only one outdoor unit is operating, at this time, the defrosting mode is determined as the first defrosting mode, and the outdoor unit is controlled to perform conventional defrosting; when the number is not less than 2 units, that is, the number of operating outdoor units is 2 or more, at this time, the defrosting mode is determined as the second defrosting mode, and multiple outdoor units are controlled to perform alternating defrosting, thereby avoiding the situation where the room temperature drops due to defrosting of multiple outdoor units at the same time, and improving the air-conditioning comfort of users.

[0050] Step S404, if the defrosting mode is the second defrosting mode, determine the target number of groups.

[0051] When the defrosting mode is the second defrosting mode, if the number of outdoor units is large, it will not only cause the defrosting time of each outdoor unit to become shorter, but also increase the operation switching time between heating and defrosting of the outdoor unit, thereby reducing the heating time and possibly causing the room temperature to drop. Based on this, the embodiment of the present invention determines the target number of groups, where the target number of groups is the number of groups corresponding to the largest proportion of the heating operation time of the outdoor unit; then, the multiple outdoor units are grouped according to the target number of groups, and alternating defrosting is performed according to the groups, thereby ensuring the heating operation time of the outdoor unit through grouping, avoiding the room temperature drop and cold air flow, and improving the air-conditioning comfort of users.

[0052] Step S406: Group the outdoor units based on the target number of groups, and control the outdoor units to defrost alternately according to each group.

[0053] The multi-connected air conditioner defrosting control method provided by the embodiment of the present invention determines the target number of groups according to the proportion of the heating operation duration, groups the outdoor units according to the target number of groups, and controls the outdoor units to defrost alternately according to each group, thereby ensuring the heating operation duration of the outdoor units and avoiding the situation that the room temperature decreases due to the reduction of the heating operation duration of the outdoor units in a multi-connected air conditioner with a large number of outdoor units, and further improving the air conditioner comfort of users.

[0054] In one implementation manner, in step S404, the process of determining the target number of groups is as follows: Obtain the preset parameters of the outdoor unit; where the preset parameters include: heating duration, defrosting duration, operation switching duration, first coefficient, and second coefficient; Calculate the target number of groups according to the preset parameters and the proportion of the heating operation duration; where the expression of the proportion of the heating operation duration is as follows:

[0055]

[0056] where P n represents the proportion of the heating operation duration, T h represents the heating duration, T df represents the defrosting duration, T ch represents the operation switching duration, α represents the first coefficient, β represents the second coefficient, and n represents the target number of groups. It should be noted that 0 < α < 1 and 0 < β < 1.

[0057] In practical applications, as the main feature of alternate defrosting, when the number of operating outdoor units increases, it not only causes the defrosting time of each outdoor unit to become shorter, but also increases the operation switching duration between heating and defrosting of the outdoor units, thereby reducing the heating operation duration. Therefore, in an interval, there is a point with the largest proportion of the heating operation duration of the outdoor units, and this point is taken as the best balance point; and, determine the number of groups of the outdoor units according to the best balance point. When the outdoor units defrost alternately according to the groups, the heating operation duration of the outdoor units is ensured, and the situation that the room temperature decreases due to the reduction of the heating operation duration of the outdoor units in a multi-connected air conditioner with a large number of outdoor units is avoided.

[0058] Here, taking the outdoor unit with the largest capacity and performing heating operation among the outdoor units of the multi-connected air conditioner as an example, the process of determining the target number of groups is described. Among them, under low temperature conditions such as the outdoor temperature of 2°C and the indoor temperature of 20°C, the heating duration for controlling this outdoor unit to perform heating operation is T h , the defrosting duration for performing defrosting operation is T df , and the operation switching duration for switching between defrosting and heating is T ch, as the number of outdoor units increases, the heat source required for defrosting increases, and the defrosting time becomes shorter. The defrosting time T when the number of groups is n dfn The calculation formula is as follows:

[0059] T dfn = 3T df ×(α n +β) (2)

[0060] In addition, when the number of groups is n, the calculation formula for the heating operation duration ratio in one interval is as follows:

[0061]

[0062] Therefore, according to formula (2) and formula (3), formula (1) can be obtained. And in formula (1), the heating operation duration ratio P n can be understood as the proportion of the heating operation time in the alternation of heating and defrosting. The lower P n is, the longer the heating time stopped due to defrosting will be, and the lower the room temperature will be; conversely, the higher P n is, the longer the heating time will be. Therefore, when P n is the largest, the best balance point is reached, and the corresponding n is the target number of groups.

[0063] For example, when the heating duration T h is 120 min, the defrosting duration T df is 12 min, the operation switching duration T ch is 0.4 min, the first coefficient α is 0.3, and the second coefficient β is 0.1, the corresponding relationship between the heating operation duration ratio P n and the number of groups n can be calculated according to formula (1). This corresponding relationship is as Figure 5 shown, where the horizontal axis represents the number of groups n, and the vertical axis represents the heating operation duration ratio P n . From this, it can be seen that when n = 3, P n reaches the maximum, that is, the target number of groups is 3 at this time.

[0064] In one implementation, before the step of grouping the outdoor units based on the target number of groups, the method further includes: if the target number of groups is not greater than the number of units, then group the outdoor units based on the target number of groups; or, if the target number of groups is greater than the number of units, then first use the number of units as the target number of groups, and then group the outdoor units based on the target number of groups.

[0065] Specifically, after the above-mentioned target number of groups is determined, before grouping the outdoor units based on the target number of groups, it is also necessary to determine whether the target number of groups is not greater than the number of units. If so, directly group the outdoor units based on the target number of groups; otherwise, if the target number of groups is greater than the number of units, first use the number of units as the target number of groups at this time, and then group the outdoor units based on the target number of groups, avoiding the situation where the outdoor units are misallocated due to the target number of groups exceeding the number of units.

[0066] In one implementation manner, in step S406, the process of grouping the outdoor units based on the target number of groups includes: obtaining the capacity of each outdoor unit, and first allocating the outdoor units to each group in turn along the first direction in the order of capacity from large to small; then, for the remaining outdoor units, continue to allocate them to each group in turn along the second direction in the order of capacity from large to small until the allocation of the outdoor units is completed; where the first direction is the direction from the first group to the last group, and the second direction is the direction from the last group to the first group.

[0067] After the above-mentioned target number of groups is determined, the outdoor units are grouped based on the target number of groups; during the grouping process, the allocation is carried out in the order of the capacity of the outdoor units from large to small, first in the first direction from the first group to the last group, and then in the second direction from the last group to the first group. For example, if there are 5 outdoor units with capacities of 12HP, 10HP, 8HP, 6HP, and 4HP respectively, and the target number of groups is 3, namely the first group (Group 1), the second group (Group 2), and the third group (Group 3); during the allocation process, first allocate in the direction from the first group (Group 1) to the third group (Group 3), as Figure 6 shown, the first group (Group 1) is the outdoor unit with 12HP, the second group (Group 2) is the outdoor unit with 10HP, and the third group (Group 3) is the outdoor unit with 8HP; then, for the remaining outdoor units (6HP and 4HP), continue to allocate them to each group in turn along the second direction in the order of capacity from large to small, as Figure 7 shown, allocate the outdoor unit with 6HP to the third group (Group 3), and allocate the outdoor unit with 4HP to the second group (Group 2). At this time, the allocation of all outdoor units is completed, and the grouping result of the 5 outdoor units is as follows: the first group (Group 1) is the outdoor unit with 12HP, the second group (Group 2) is the outdoor unit with 10HP and the outdoor unit with 4HP, and the third group (Group 3) is the outdoor unit with 8HP and the outdoor unit with 6HP.

[0068] It should be noted that for the remaining outdoor units, if there are still some outdoor units not allocated after being sequentially allocated to each group along the second direction, then at this time, they are sequentially allocated to each group along the first direction first and then the second direction until all the outdoor units are allocated. Moreover, whether allocating along the first direction or the second direction, the allocation is carried out in the order of the outdoor unit capacity from large to small.

[0069] In particular, if the target number of groups is equal to the number of units, then each outdoor unit can be allocated to each group along the first direction or the second direction in the order of capacity from large to small. In some scenarios, since the number of units is the same as the target number of groups, it is also possible to randomly allocate each outdoor unit to each group without considering the capacity, and specific adaptive adjustments can be made according to the actual situation.

[0070] In one implementation, after the step of grouping the outdoor units based on the target number of groups, the method further includes: obtaining the total capacity of the outdoor units in each group; if the total capacity of any one group is greater than the sum of the total capacities of the remaining groups, then perform an update process on the target number of groups, and re-group the outdoor units based on the updated target number of groups until the total capacity of any one group is not greater than the sum of the total capacities of the remaining groups.

[0071] Specifically, the outdoor units are grouped by the target number of groups to make the total capacity of the outdoor units in each group consistent (or approximately uniform). Since the heat required for defrosting of the defrosting outdoor unit is generated by the remaining non-defrosting outdoor units, if the total capacity of a certain group is too large, it will lead to problems such as insufficient heat source and extended defrosting time when the group is defrosting. Therefore, after the outdoor units are grouped based on the target number of groups, the total capacity of the outdoor units in each group is also obtained; at this time, it is judged whether the total capacity of any one group is greater than the sum of the total capacities of the remaining groups. If so, perform an update process on the target number of groups, and re-group the outdoor units based on the updated target number of groups until the total capacity of any one group is not greater than the sum of the total capacities of the remaining groups.

[0072] Among them, in the process of performing the update process on the target number of groups, the embodiment of the present invention updates the target number of groups according to target number of groups = target number of groups + 1, that is, when the total capacity of any one group is greater than the sum of the total capacities of the remaining groups, the target number of groups is increased and the outdoor units are re-grouped. For example, assume that the capacities of the outdoor units are 12HP, 10HP, and 8HP respectively. When the target number of groups is 2, the result of grouping the outdoor units according to the target number of groups is as Figure 8As shown, the first group (Group 1) is an outdoor unit with 12 HP, and the second group (Group 2) is an outdoor unit with 10 HP and an outdoor unit with 8 HP. At this time, when the outdoor units in the second group (Group 2) defrost, since the total capacity of the second group (Group 2) is relatively large, the heat generated by the outdoor units in the first group (Group 1) cannot meet the heat required for defrosting of the second group (Group 2), resulting in an extended defrost time for the outdoor units in the second group (Group 2).

[0073] At this time, update the target number of groups to obtain a new target number of groups, which is 3. At this time, the target number of groups is not greater than the number of units, and the result of regrouping the outdoor units again is as Figure 9 shown. The first group (Group 1) is an outdoor unit with 12 HP, the second group (Group 2) is an outdoor unit with 10 HP, and the third group (Group 3) is an outdoor unit with 8 HP. At this time, when the outdoor units in the first group (Group 1) defrost, since the outdoor units in the second group (Group 2) and the third group (Group 3) can absorb heat (perform evaporation work), the heat required for defrosting of the outdoor units in the first group (Group 1) is thus satisfied.

[0074] Similarly, when the outdoor units in the second group (Group 2) defrost, since the outdoor units in the first group (Group 1) and the third group (Group 3) can absorb heat (perform evaporation work), the heat required for defrosting of the outdoor units in the second group (Group 2) is thus satisfied; similarly, when the outdoor units in the third group (Group 3) defrost, since the outdoor units in the second group (Group 2) and the first group (Group 1) can absorb heat (perform evaporation work), the heat required for defrosting of the outdoor units in the third group (Group 3) is thus satisfied.

[0075] Therefore, by updating the target number of groups, the total capacity of each group after grouping is kept consistent. Thus, when the outdoor units defrost alternately according to each group, the heat generated by the outdoor units in the groups that are performing heating can meet the heat required for defrosting of the outdoor units in the group that is defrosting, avoiding a decrease in room temperature and cold air flow, and thereby improving the air-conditioning comfort of users.

[0076] In an implementation manner, before the step of regrouping the outdoor units based on the updated target number of groups, the method further includes: determining whether the updated target number of groups is not greater than the number of units; if so, regroup the outdoor units based on the updated target number of groups.

[0077] After the above-mentioned processing of incrementing the target number of groups by 1, for the updated target number of groups, before regrouping the outdoor units, it is also necessary to re-determine whether the updated target number of groups is not greater than the number of units. If so, the outdoor units are regrouped based on the updated target number of groups. For example, in the order of decreasing capacity of the outdoor units, the outdoor units are sequentially assigned to each group along the first direction first and then the second direction. The specific process of regrouping can refer to the foregoing embodiments, and the embodiments of the present invention will not be described in detail again.

[0078] Therefore, by updating the target number of groups, the increase in the number of groups of outdoor units is achieved, and the outdoor units are regrouped according to the updated target number of groups, ensuring that the total capacity of the outdoor units in each group remains consistent (or approximately uniform). Thus, in the alternating defrosting process, the heat generated by the outdoor units in the heating operation can meet the heat required for defrosting the outdoor units in the defrosting operation. At the same time, the decrease in room temperature and cold air flow are avoided, improving the air-conditioning comfort of users.

[0079] In addition, the method further includes: if the updated target number of groups is greater than the number of units, controlling the defrosting mode to switch from the second defrosting mode to the first defrosting mode, and controlling the outdoor units to operate according to the first defrosting mode. When the updated target number of groups is greater than the number of units, it indicates that there is a large difference in the capacity between the outdoor units. At this time, alternating defrosting cannot be performed between multiple outdoor units. To ensure the service life of the multi-connected air conditioner, at this time, the defrosting requirement of the multi-connected air conditioner needs to be given priority. Therefore, the defrosting mode is controlled to switch from the second defrosting mode to the first defrosting mode, and multiple outdoor units are controlled to operate according to the first defrosting mode. After the defrosting is completed, the outdoor units are controlled to perform heating operation to meet the heating requirements of users.

[0080] Embodiment 2

[0081] Based on the above embodiments, an embodiment of the present invention provides another multi-connected air conditioner defrosting control method, which describes the defrosting control process of the multi-connected air conditioner. As Figure 10 shown, the method includes the following steps:

[0082] Step S1002, obtaining the number of operating outdoor units m; that is, when the multi-connected air conditioner needs to defrost, first obtain the number of operating outdoor units m in the multi-connected air conditioner.

[0083] Step S1004, determining whether m≥2; that is, determining whether the number of units m is not less than the preset number of units 2. If so, execute step S1008; if not, execute step S1006.

[0084] Step S1006, determining the defrosting mode as the first defrosting mode; that is, when the number of units is less than the preset number of units, determine the defrosting mode as the first defrosting mode, and control the outdoor units to defrost according to the first defrosting mode.

[0085] Step S1008, determine that the defrosting mode is the second defrosting mode; that is, when the number of units is not less than the preset number, determine that the defrosting mode is the second defrosting mode, and control the outdoor unit to defrost according to the second defrosting mode.

[0086] Step S1010, determine the target number of groups n; that is, determine the target number of groups n according to formula (1), and the specific determination process can refer to the foregoing embodiments, and the embodiments of the present invention will not be elaborated in detail herein.

[0087] Step S1012, judge: n ≤ m; that is, judge whether the target number of groups n is not greater than the number of units m. If so, execute step S1016; if not, execute step S1014.

[0088] Step S1014, use the number of units m as the target number of groups n; that is, when the target number of groups n is greater than the number of units m, first use the number of units m as the target number of groups n, and then group the outdoor units based on the target number of groups n (at this time n = m).

[0089] Step S1016, group the outdoor units based on the target number of groups n; the specific grouping process can refer to the foregoing embodiments, and the embodiments of the present invention will not be elaborated in detail herein.

[0090] Step S1018, judge: the total capacity of any group > the sum of the total capacities of the remaining groups; that is, after grouping, judge whether the total capacity of any group is greater than the sum of the total capacities of the remaining groups. If not, execute step S1020; if so, execute step S1022.

[0091] Step S1020, control the outdoor unit to defrost alternately according to each group; that is, when the total capacity of any group is not greater than the sum of the total capacities of the remaining groups, it means that the total capacities of each group are consistent (or roughly uniform). At this time, control the outdoor unit to defrost alternately according to each group, so that in the alternate defrosting, the heat generated by the outdoor unit in the heating operation can meet the heat required for defrosting of the outdoor unit in the defrosting operation, and at the same time, the reduction of room temperature and cold air flow are avoided, improving the air-conditioning comfort of users.

[0092] Step S1022, n = n + 1; that is, when the total capacity of any group is greater than the sum of the total capacities of the remaining groups, it means that there is a large deviation in the total capacities of each group. At this time, update the target number of groups n according to n = n + 1 to obtain the updated target number of groups n.

[0093] Step S1024, judge: n ≤ m; that is, judge whether the updated target number of groups n is not greater than the number of units m. If so, return to step S1016 to re-group the outdoor units based on the updated target number of groups n; if not, execute step S1026.

[0094] Step S1026, control the defrosting mode to switch from the second defrosting mode to the first defrosting mode; that is, when the updated target number of groups n is greater than the number of units m, it indicates that there is a large difference in capacity between the outdoor units. At this time, the outdoor units cannot perform alternating defrosting. To ensure the service life of the multi-connected air conditioner, the defrosting demand of the multi-connected air conditioner needs to be prioritized at this time. Therefore, control the defrosting mode to switch from the second defrosting mode to the first defrosting mode, and control all outdoor units to operate according to the first defrosting mode. After the defrosting is completed, control the outdoor units to perform heating operation to meet the heating demand of the user.

[0095] Exemplarily, when 4 outdoor units are divided into two groups (i.e., group 1 and group 2, with two outdoor units in each group) and alternating defrosting is performed according to the two groups, an interval L is as Figure 11 shown. When the outdoor units in group 1 are defrosting in L1, at this time, the outdoor units in group 2 are in L4; among them, within L4, the indoor units stop, and the outdoor units in group 2 are in heating operation to meet the defrosting heat of the outdoor units in group 1; similarly, when the outdoor units in group 2 are defrosting in L1, at this time, the outdoor units in group 1 are in L4; among them, within L4, the indoor units stop, and the outdoor units in group 1 are in heating operation to meet the defrosting heat of the outdoor units in group 2.

[0096] In addition, by performing grouped defrosting on the outdoor units, compared with the solution S2 as Figure 3 shown, the number of times of operation switching duration in the case of multiple outdoor units is also reduced, thus ensuring the heating duration in an interval, avoiding the reduction of the room temperature when the outdoor units are defrosting, and further improving the air conditioner comfort of the user.

[0097] Therefore, the multi-connected air conditioner defrosting control method provided by the embodiments of the present invention groups the outdoor units according to the target number of groups, and controls the outdoor units to perform alternating defrosting according to each group, thereby ensuring the heating operation duration of the outdoor units, avoiding the situation where the room temperature decreases due to the reduction of the heating operation duration of the outdoor units in a multi-connected air conditioner with a large number of outdoor units, and further improving the air conditioner comfort of the user.

[0098] Embodiment III

[0099] Based on the above method embodiments, the embodiments of the present invention further provide a multi-connected air conditioner, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the above multi-connected air conditioner defrosting control method is implemented.

[0100] The multi-connected air conditioner provided by the embodiments of the present invention has the same technical features as the multi-connected air conditioner defrosting control method provided by the above embodiments, so it can also solve the same technical problems and achieve the same technical effects.

[0101] See Figure 12As shown, the multi-connected air conditioner includes a processor 100 and a memory 101. The memory 101 stores machine-executable instructions that can be executed by the processor 100. The processor 100 executes the machine-executable instructions to implement the defrost control method of the multi-connected air conditioner described above.

[0102] Furthermore, Figure 12 The multi-connected air conditioner shown also includes a bus 102 and a communication interface 103. The processor 100, the communication interface 103, and the memory 101 are connected through the bus 102.

[0103] Among them, the memory 101 may include a high-speed random access memory (RAM, Random Access Memory), and may also include a non-volatile memory, such as at least one disk memory. The communication connection between this system network element and at least one other network element is realized through at least one communication interface 103 (which can be wired or wireless). The Internet, wide area network, local area network, metropolitan area network, etc. can be used. The bus 102 can be an ISA (Industrial Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus, or an EISA (Enhanced Industry Standard Architecture) bus, etc. The above bus can be divided into an address bus, a data bus, a control bus, etc. For the sake of simplicity of representation, Figure 12 only a bidirectional arrow is used in the figure, but it does not mean that there is only one bus or one type of bus.

[0104] The processor 100 may be an integrated circuit chip with the ability to process signals. In the implementation process, each step of the above method can be completed by the integrated logic circuit of the hardware in the processor 100 or the instructions in the form of software. The above-mentioned processor 100 may be a general-purpose processor, including a central processing unit (CPU for short), a network processor (NP for short), etc.; it may also be a digital signal processor (DSP for short), an application specific integrated circuit (ASIC for short), a field-programmable gate array (FPGA for short) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. It can implement or execute the various methods, steps and logic block diagrams disclosed in the embodiments of the present invention. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc. The steps of the method disclosed in combination with the embodiments of the present invention can be directly embodied as being executed and completed by a hardware decoding processor, or executed and completed by a combination of the hardware and software modules in the decoding processor. The software module may be located in a mature storage medium in the art such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. This storage medium is located in the memory 101, and the processor 100 reads the information in the memory 101 and combines its hardware to complete the steps of the method in the foregoing embodiments.

[0105] This embodiment also provides a machine-readable storage medium. The machine-readable storage medium stores machine-executable instructions. When the machine-executable instructions are called and executed by the processor, the machine-executable instructions cause the processor to implement the above-mentioned multi-connected unit defrosting control method.

[0106] The multi-connected unit defrosting control method and the computer program product of the multi-connected unit provided by the embodiments of the present invention include a computer-readable storage medium storing program code. The instructions included in the program code can be used to execute the method described in the foregoing method embodiments. For the specific implementation, reference can be made to the method embodiments, which will not be elaborated here.

[0107] Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the systems and devices described above can refer to the corresponding processes in the foregoing method embodiments, which will not be elaborated here.

[0108] In addition, in the description of the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "coupled" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0109] If the above-mentioned functions are implemented in the form of software function units and sold or used as independent products, they can be stored in a non-volatile computer-readable storage medium executable by a processor. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROMs), random access memories (RAMs), magnetic disks, or optical discs that can store program codes.

[0110] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0111] Finally, it should be noted that the above-described embodiments are only specific embodiments of the present invention, used to illustrate the technical solutions of the present invention, rather than limiting it. The protection scope of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that any person skilled in the technical field can still modify the technical solutions recorded in the foregoing embodiments, or can easily think of changes, or perform equivalent replacements on some of the technical features; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A defrost control method for a multi-connected air conditioner, the multi-connected air conditioner comprising at least one outdoor unit, characterized in that, The method includes: Obtaining the number of outdoor units operating in the multi-connected air conditioner, and determining a defrosting mode according to the number; wherein, the defrosting mode includes a first defrosting mode and a second defrosting mode, the first defrosting mode is a mode in which the outdoor unit only performs defrosting operation, and the second defrosting mode is an alternative defrosting mode in which the outdoor unit performs defrosting and heating operation alternately; If the defrosting mode is the second defrosting mode, determining a target number of groups; wherein, the target number of groups is the number of groups corresponding to the largest proportion of the heating operation duration of the outdoor unit; Grouping the outdoor units based on the target number of groups, and controlling the outdoor units to perform alternative defrosting according to each group.

2. The method according to claim 1, wherein The step of grouping the outdoor units based on the target number of groups includes: Obtaining the capacity of each outdoor unit, and first sequentially allocating the outdoor units to each group along a first direction in descending order of the capacity; then, for the remaining outdoor units, continuing to sequentially allocate them to each group along a second direction in descending order of the capacity until all outdoor units are allocated; wherein, the first direction is the direction from the first group to the last group, and the second direction is the direction from the last group to the first group.

3. The method according to claim 2, wherein After the step of grouping the outdoor units based on the target number of groups, the method further includes: Obtaining the total capacity of the outdoor units in each group; If the total capacity of any group is greater than the sum of the total capacities of the remaining groups, performing an update process on the target number of groups, and re-grouping the outdoor units based on the updated target number of groups until the total capacity of any group is not greater than the sum of the total capacities of the remaining groups.

4. The method according to claim 3, wherein Before the step of re-grouping the outdoor units based on the updated target number of groups, the method further includes: Judging whether the updated target number of groups is not greater than the number; If so, re-grouping the outdoor units based on the updated target number of groups.

5. The method according to claim 4, wherein The method further includes: If the updated target number of groups is greater than the number, controlling the defrosting mode to switch from the second defrosting mode to the first defrosting mode, and controlling the outdoor unit to operate according to the first defrosting mode.

6. The method according to claim 1, wherein Before the step of grouping the outdoor units based on the target number of groups, the method further includes: If the target number of groups is not greater than the number, grouping the outdoor units based on the target number of groups; or, If the target number of groups is greater than the number, first taking the number as the target number of groups, and then grouping the outdoor units based on the target number of groups.

7. The method according to claim 1, wherein The step of determining the target number of groups includes: Obtaining the preset parameters of the outdoor unit; wherein, the preset parameters include: heating duration, defrosting duration, operation switching duration, a first coefficient, and a second coefficient; Calculating the target number of groups according to the preset parameters and the proportion of the heating operation duration; Wherein, the expression of the proportion of the heating operation duration is as follows: Among them, P n represents the heating operation duration ratio, T h represents the heating duration, T df represents the defrosting duration, T ch represents the operation switching duration, α represents the first coefficient, β represents the second coefficient, and n represents the target number of groups.

8. The method according to claim 1, wherein The step of determining the defrosting mode according to the number includes: If the number is less than a preset number, determining the defrosting mode as the first defrosting mode; or, If the number of units is not less than the preset number of units, determine that the defrosting mode is the second defrosting mode.

9. A multi-connected unit, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method described in any one of claims 1-8 above.

10. A computer-readable storage medium, characterized in that, A computer program is stored on the computer-readable storage medium, and when the computer program is run by a processor, it executes the steps of the method described in any one of claims 1-8 above.

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