Control method and system of multi-connected air conditioning system

Abstract

The application discloses a control method and system of a multi-connected air conditioning system, the multi-connected air conditioning system comprising at least two outdoor units, the multi-connected air conditioning system comprising a heating mode; the control method is used for the heating mode, and the control method comprises the following steps: controlling loading or unloading of each outdoor unit based on a preset target condensing temperature; monitoring low-pressure values of low-pressure sides of all outdoor units and calculating an average value of the low-pressure values of the outdoor units; for any outdoor unit, calculating a difference value between a low-pressure value of the outdoor unit and the average low-pressure value to obtain a low-pressure deviation value corresponding to the outdoor unit; correcting the preset target condensing temperature based on the low-pressure deviation value corresponding to each outdoor unit to obtain a corrected target condensing temperature corresponding to each outdoor unit; and controlling loading or unloading of the corresponding outdoor unit based on the corrected target condensing temperature. According to the control method, the stability of the multi-connected air conditioning system is improved, the overall energy efficiency of the system is further optimized, and the use experience of the user is more stable and comfortable.

Description

Technical Field

[0001] This invention relates to the field of air conditioning system control technology, and in particular to a control method and system for a multi-split air conditioning system. Background Technology

[0002] A multi-split air conditioning system is a single-cycle system consisting of one or more air-cooled outdoor units connected to one or more direct-evaporation indoor units of different or identical types and capacities. This system can directly supply treated air to one or more areas, enabling centralized control and zoned management. Due to its high efficiency, energy saving, and flexibility, multi-split air conditioning systems are widely used in commercial and residential buildings.

[0003] Currently, in heating mode, multi-split air conditioning systems generally employ a unified target condensing temperature control strategy for the outdoor units. Specifically, the control system presets a target condensing temperature value. Then, based on the comparison between the current condensing temperature of each outdoor unit and the target value, the control system dynamically adjusts the compressor's operating status: if the current condensing temperature is lower than the target value, the outdoor unit is instructed to increase its load to improve heating efficiency; conversely, the load is reduced to avoid overheating.

[0004] However, this control strategy is prone to instability when faced with uneven cooling capacity of outdoor units in the air conditioning system or defects in system installation. Specifically, due to differences in the performance of each outdoor unit, if the outdoor unit is controlled to condense at the same target condensing temperature, the operating parameters of the outdoor unit will vary and may deviate from the preset safe operating range, thus triggering fault alarms such as high-pressure protection, low-pressure protection, and excessively high exhaust temperature. Such instability not only impairs the overall stability and energy efficiency of the air conditioning system but also affects the customer's user experience. Summary of the Invention

[0005] The purpose of this invention is to provide a control method and system for a multi-split air conditioning system that can correct the target condensing temperature of the outdoor unit to enhance the control stability and operating efficiency of the multi-split air conditioning system.

[0006] To achieve the above objectives, the present invention discloses a multi-split air conditioning system, the multi-split air conditioning system comprising at least two outdoor units, and the multi-split air conditioning system including a heating mode;

[0007] This invention also discloses a control method for the above-mentioned multi-split air conditioning system, the control method being used in heating mode, the control method comprising:

[0008] The loading or unloading of each outdoor unit is controlled based on the preset target condensation temperature;

[0009] Monitor the low-pressure value on the low-pressure side of all outdoor units and calculate the average low-pressure value of all outdoor units to obtain the average low-pressure value;

[0010] For any of the outdoor units, calculate the difference between the low-pressure value of the outdoor unit and the average low-pressure value to obtain the low-pressure deviation value corresponding to the outdoor unit;

[0011] Based on the low-pressure deviation value corresponding to each of the outdoor units, the preset target condensing temperature is corrected to obtain the corrected target condensing temperature corresponding to each of the current outdoor units;

[0012] Based on the corrected target condensing temperature, the outdoor unit's load or unload is controlled accordingly.

[0013] Specifically, the low-pressure deviation value LS_cu is calculated based on the following formula. n ;

[0014] LS_cu n =LS n -LS_aver

[0015] Where n represents the serial number of each external unit, LS_cu n LS represents the low-pressure deviation value corresponding to the nth outdoor unit. n LS_aver represents the low-pressure value corresponding to the nth outdoor unit, and LS_aver represents the average low-pressure value.

[0016] Specifically, the calculation method for the corrected target condensation temperature includes:

[0017] When the low-pressure deviation value corresponding to the outdoor unit is greater than or equal to a preset first threshold, the corrected target condensing temperature of the outdoor unit is the difference between the target condensing temperature and the preset correction value;

[0018] When the low-pressure deviation value corresponding to the outdoor unit is less than the first threshold and greater than the preset second threshold, the corrected target condensing temperature of the outdoor unit is the target condensing temperature;

[0019] When the low-pressure deviation value corresponding to the outdoor unit is less than or equal to the second threshold, the corrected target condensing temperature of the outdoor unit is the sum of the target condensing temperature and the correction value.

[0020] Specifically, the method for loading or unloading the outdoor unit based on the modified target condensing temperature control includes:

[0021] Obtain the current energy demand and corresponding condensing temperature of each outdoor unit;

[0022] Calculate the average condensing temperature of all the outdoor units to obtain the average condensing temperature;

[0023] Calculate the difference between the corrected target condensing temperature and the average condensing temperature corresponding to each of the outdoor units to obtain the corrected judgment value corresponding to each of the outdoor units;

[0024] Based on the corresponding correction judgment value of each outdoor unit and the current energy demand value, the energy demand value of each outdoor unit is corrected.

[0025] Furthermore, the control method further includes:

[0026] When the absolute value of the correction judgment value is less than or equal to the preset third threshold, the current energy demand value of the outdoor unit remains unchanged;

[0027] When the absolute value of the correction judgment value is greater than the third threshold, the energy demand deviation value is calculated based on the correction judgment value corresponding to each of the outdoor units, and the energy demand value required by each of the outdoor units is calculated based on the energy demand deviation value and the current energy demand value, so as to obtain the corrected energy demand value corresponding to each of the outdoor units.

[0028] Furthermore, when the absolute value of the correction judgment value is greater than the third threshold, it is also necessary to determine whether the correction judgment value is positive. If it is, the corrected energy demand value of the outdoor unit is the sum of the current energy demand value and the energy demand deviation value. If not, the corrected energy demand value of the outdoor unit is the difference between the current energy demand value and the energy demand deviation value.

[0029] Furthermore, it also includes an energy demand correction cycle, in which each of the outdoor units re-corrects its current energy demand value every time it runs for one energy demand correction cycle.

[0030] The present invention also discloses a multi-split air conditioning system, the multi-split air conditioning system including a control system, the control system operating based on the control method described above.

[0031] This invention also discloses a control system for a multi-split air conditioning system, comprising:

[0032] One or more processors;

[0033] Memory;

[0034] and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the programs including instructions for performing the control methods as described above.

[0035] The present invention also discloses a computer-readable storage medium comprising a computer program that can be executed by a processor to perform the control method described above.

[0036] Compared with existing technologies, the control method provided by the present invention further refines the load adjustment strategy for outdoor units by introducing the overall average low pressure value of the outdoor units as a key condition. The control method provided by the present invention first monitors the low pressure value of each outdoor unit in the system, then adjusts the target condensing temperature of each outdoor unit based on the actual low pressure value, and then guides each outdoor unit to appropriately adjust its load based on the target condensing temperature. In this process, the operating states of the outdoor units dynamically influence each other, achieving a relatively balanced capacity distribution. This control method not only improves the stability of multi-split air conditioning systems but also significantly improves the overall energy efficiency of the system by optimizing load distribution, thereby providing users with a more continuous, efficient, and comfortable user experience. Attached Figure Description

[0037] Figure 1 This is a flowchart of the control method according to an embodiment of the present invention.

[0038] Figure 2 This is a flowchart of the control method for loading or unloading the outdoor unit in an embodiment of the present invention.

[0039] Figure 3 This is a flowchart of a method for controlling the loading or unloading of the outdoor unit in another embodiment of the present invention. Detailed Implementation

[0040] To illustrate the technical content, structural features, objectives, and effects of the present invention in detail, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0041] This embodiment discloses a multi-split air conditioning system, which includes at least two outdoor units and includes a heating mode.

[0042] Based on this structure, this embodiment discloses a control method and system for a multi-split air conditioning system to enhance the control stability and operating efficiency of the multi-split air conditioning system, thereby improving the stability and overall energy efficiency of the multi-split air conditioning system and bringing users a more continuous, efficient and comfortable user experience.

[0043] See Figure 1 As shown, the control method in this embodiment specifically includes the following steps:

[0044] S11: Controls the loading or unloading of each outdoor unit based on the preset target condensing temperature.

[0045] S12: Monitor the low pressure value on the low pressure side of all outdoor units, and calculate the average value of the low pressure values of all outdoor units to obtain the average low pressure value.

[0046] S13: Calculate the difference between the low pressure value corresponding to each outdoor unit and the average low pressure value to obtain the low pressure deviation value corresponding to each outdoor unit.

[0047] S14: Correct the preset target condensing temperature based on the corresponding low pressure deviation value of each outdoor unit, so as to obtain the corrected target condensing temperature corresponding to each current outdoor unit.

[0048] S15: Control the loading or unloading of the corresponding outdoor unit based on the corrected target condensing temperature.

[0049] Specifically, the low pressure deviation value of each outdoor unit is calculated based on the following formula:

[0050] LS_cu n =LS n -LS_aver

[0051] wherein n represents the serial number of each outdoor unit, LS_cu n represents the low pressure deviation value corresponding to the nth outdoor unit, LS n represents the low pressure value corresponding to the nth outdoor unit, and LS_aver represents the average low pressure value.

[0052] Specifically, assume that the target condensing temperature is T p , the corrected target condensing temperature is T sn , n represents the serial number of each outdoor unit, a and b are respectively the preset first threshold and second threshold related to the low pressure deviation value LS_cu n , the preset correction value of the corrected target condensing temperature is T1, and the calculation method of the corrected target condensing temperature T sn includes:

[0053] When the low pressure deviation value corresponding to the outdoor unit is greater than or equal to the preset first threshold, the corrected target condensing temperature of the outdoor unit is the difference between the target condensing temperature and the preset correction value, that is, when LS_cu n ≥a, T sn =T p -T1;

[0054] When the low pressure deviation value corresponding to the outdoor unit is less than the first threshold and greater than the preset second threshold, the corrected target condensing temperature of the outdoor unit is the target condensing temperature, that is, when b<LS_cu n <a, T sn =T p ;

[0055] When the low-pressure deviation value corresponding to the outdoor unit is less than or equal to the second threshold, the corrected target condensing temperature of the outdoor unit is the sum of the target condensing temperature and the correction value, that is, when LS_cu n When ≤b, T sn =T p -T1.

[0056] Among them, the target condensation temperature T p The value range is 35~55℃, with a preferred value of 48℃; the preferred value of a is 1, the preferred value of b is -1, and the preferred value of T1 is 2.

[0057] On the other hand, see Figure 2 As shown, the target condensation temperature T is corrected. sn Methods for controlling the loading or unloading of the corresponding outdoor unit include:

[0058] S21: Obtain the current energy demand E of each outdoor unit. n and the corresponding condensation temperature T;

[0059] S22: Calculate the average condensing temperature T of all outdoor units to obtain the average condensing temperature T_aver. n ;

[0060] S23: Calculate the corrected target condensing temperature T for each outdoor unit. sn and average condensation temperature T_aver n The difference is used to obtain the corresponding correction judgment value q for each outdoor unit. n ;

[0061] S24: Based on the corresponding correction judgment value q of each outdoor unit n and the current energy demand value E n The energy requirement E for each outdoor unit n Make corrections.

[0062] To take a closer look, see Figure 3 As shown, it also includes a preset third threshold c related to the correction judgment value, and step S24 further includes:

[0063] S241: Determine the absolute value of the modified judgment value |q n |Is it less than or equal to the third threshold c? If yes, then jump to step S242; if no, then jump to step S243.

[0064] S242: Maintain the current energy demand value E of the outdoor unit. n constant.

[0065] S243: Based on the corresponding correction judgment value q of each outdoor unit n Calculate the energy demand deviation value K n And based on the energy demand deviation value Kn and the current energy demand value E n Calculate the corrected energy requirement for each outdoor unit to obtain the corrected energy requirement E for each outdoor unit. n ′.

[0066] The value of the third threshold c ranges from [0.2, 4.0], with a preferred value of 1.5.

[0067] Furthermore, when |q n When |>c, determine and correct the judgment value q. n Is it a positive value? If so, the outdoor unit's correction energy requirement is E. n ′ represents the current energy demand value E n Deviation value K n The sum of, i.e., E n ′=E n +K n If not, the outdoor unit's correction energy requirement is E. n ′ represents the current energy demand value E n Deviation value K n The difference, i.e., E n ′=E n -K n .

[0068] Specifically, it is also necessary to monitor the high-voltage value HS on the high-voltage side of the multi-split air conditioning system. n To determine the energy demand deviation value K n Energy requirement deviation value K n The determination is shown in Table 1 below:

[0069] Table 1 Energy Demand Deviation Values ​​K n surface

[0070]

[0071]

[0072] For example, assuming that the rated capacity of outdoor unit 1 is 7HP, the current detected correction judgment value q1 of outdoor unit 1 is -11℃, and the high voltage value HS1 on the high voltage side is 36bar. At this time, the correction judgment value q1 < -10 and the high voltage value HS1 > 35bar. According to Table 1, the energy demand deviation value K1 of the outdoor unit can be obtained as 7 / 10E1.

[0073] It should be noted that the rated capacity of outdoor units on the market is mostly manufactured in increments of 2HP. If the rated capacity of the actual outdoor unit used is not within the range included in Table 1, the optimal energy demand deviation value should be calculated and selected based on the actual rated capacity of the outdoor unit. Then, based on this optimal energy demand deviation value, the control method of this embodiment should be applied to correct the energy demand value E. n The calculation is performed. The following example illustrates this:

[0074] Assuming outdoor unit 1 has a rated capacity of 7HP and a current energy requirement of 4HP, the corrected condensing temperature T of outdoor unit 1 is... s1 The difference q1 between the average condensing temperature T_aver1 and the value is -2. The corrected judgment value q1 = -2 is a non-positive negative number. The energy demand deviation value K1 can be obtained from Table 1 as 1. The corrected energy demand value E1′ is the difference between the current energy demand value E1 and the energy demand deviation value K1, that is, E1′ = E1 - K1 = 7 - 1 = 6HP.

[0075] Furthermore, this embodiment also includes an energy demand correction cycle. Each outdoor unit recalculates its current energy demand value after each energy demand correction cycle. Multiple corrections of the current energy demand value facilitate better load distribution within the multi-split system, allowing the outdoor units to reach the user's cooling temperature requirements more quickly. The preferred value for the correction cycle is 32 seconds.

[0076] In another preferred embodiment of the present invention, a multi-split air conditioning system is also disclosed, which includes a control system that operates based on the control method described above.

[0077] This invention also discloses a control system for a multi-split air conditioning system, comprising one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the programs including instructions for performing the control method described above. The processor may be a general-purpose central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, used to execute the relevant programs to perform the control method of the embodiments of this application.

[0078] The present invention also discloses a computer-readable storage medium comprising a computer program executable by a processor to perform the control method described above. The computer-readable storage medium can be any available medium accessible to a computer or a data storage device such as a server or data center integrating one or more available media. The available medium can be read-only memory (ROM), random access memory (RAM), or magnetic media, such as floppy disks, hard disks, magnetic tapes, magnetic disks, or optical media, such as digital versatile discs (DVDs), or semiconductor media, such as solid-state drives (SSDs).

[0079] This application also discloses a computer program product or computer program, which includes computer instructions stored in a computer-readable storage medium. A processor of an electronic device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the electronic device to perform the aforementioned control method.

[0080] The above-disclosed embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, any equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. A control method for a multi-split air conditioning system, characterized in that, The multi-split air conditioning system includes at least two outdoor units, and the multi-split air conditioning system includes a heating mode; the control method is used in the heating mode, and the control method includes: The loading or unloading of each outdoor unit is controlled based on the preset target condensation temperature; Monitor the low-pressure value on the low-pressure side of all outdoor units and calculate the average low-pressure value of all outdoor units to obtain the average low-pressure value; For any of the outdoor units, calculate the difference between the low-pressure value of the outdoor unit and the average low-pressure value to obtain the low-pressure deviation value corresponding to the outdoor unit; Based on the low-pressure deviation value corresponding to each of the outdoor units, the preset target condensing temperature is corrected to obtain the corrected target condensing temperature corresponding to each of the current outdoor units; The loading or unloading of the outdoor unit is controlled based on the corrected target condensing temperature. The loading or unloading of the outdoor unit corresponding to the modified target condensing temperature control includes: Obtain the current energy demand and corresponding condensing temperature of each outdoor unit, as well as the high-pressure value on the high-pressure side of the multi-split air conditioning system; Calculate the average condensing temperature of all the outdoor units to obtain the average condensing temperature; Calculate the difference between the corrected target condensing temperature and the average condensing temperature corresponding to each of the outdoor units to obtain the corrected judgment value corresponding to each of the outdoor units; When the absolute value of the correction judgment value is less than or equal to the preset third threshold, the current energy demand value of the outdoor unit remains unchanged; When the absolute value of the correction judgment value is greater than the third threshold, the energy demand deviation value is calculated based on the correction judgment value and the high voltage value corresponding to each of the outdoor units, and the correction energy demand value corresponding to each of the outdoor units is obtained based on the energy demand deviation value and the current energy demand value.

2. The control method for a multi-split air conditioning system according to claim 1, characterized in that, The low-pressure deviation value is calculated based on the following formula. ; in, This indicates the serial number of each outdoor unit. Indicates the relationship with the first The corresponding low-pressure deviation value for the outdoor unit. Indicates the relationship with the first The low-pressure value corresponding to the outdoor unit mentioned above. This represents the average low pressure value.

3. The control method for a multi-split air conditioning system according to claim 1, characterized in that, The calculation method for the corrected target condensation temperature includes: When the low-pressure deviation value corresponding to the outdoor unit is greater than or equal to a preset first threshold, the corrected target condensing temperature of the outdoor unit is the difference between the target condensing temperature and the preset correction value; When the low-pressure deviation value corresponding to the outdoor unit is less than the first threshold and greater than the preset second threshold, the corrected target condensing temperature of the outdoor unit is the target condensing temperature; When the low-pressure deviation value corresponding to the outdoor unit is less than or equal to the second threshold, the corrected target condensing temperature of the outdoor unit is the sum of the target condensing temperature and the correction value.

4. The control method for a multi-split air conditioning system according to claim 1, characterized in that, When the absolute value of the correction judgment value is greater than the third threshold, it is determined whether the correction judgment value is positive. If it is, the corrected energy demand value of the outdoor unit is the sum of the current energy demand value and the energy demand deviation value. If not, the corrected energy demand value of the outdoor unit is the difference between the current energy demand value and the energy demand deviation value.

5. The control method for a multi-split air conditioning system according to claim 4, characterized in that, It also includes an energy demand correction cycle, in which each of the outdoor units re-corrects its current energy demand value every time it runs for one such energy demand correction cycle.

6. A multi-split air conditioning system, characterized in that, The multi-split air conditioning system includes a control system, which operates based on the control method described in any one of claims 1 to 5.

7. A control system for a multi-split air conditioning system, characterized in that, include: One or more processors; Memory; And one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the programs including instructions for performing the control method as described in any one of claims 1 to 5.

8. A computer-readable storage medium, characterized in that, Includes a computer program that can be executed by a processor to perform the control method as described in any one of claims 1 to 5.

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