Noise control methods for multi-split air conditioners

Abstract

This invention discloses a noise control method for a multi-split air conditioner, comprising: during air conditioner cooling operation, acquiring the real-time noise value of the indoor environment where a selected indoor unit is located and the real-time operating load of all indoor units; when the real-time noise value is greater than a real-time noise threshold, performing the following noise reduction control: when the real-time operating load is greater than a set operating load, controlling at least the operating parameters of the selected indoor unit and the operating parameters of other indoor units in operation to reduce the noise generated by the selected indoor unit; when the real-time operating load is not greater than the set operating load, keeping the operating parameters of the other indoor units in operation unchanged, and controlling at least the operating parameters of the selected indoor unit to reduce the noise generated by the selected indoor unit. Applying this invention, air conditioner control is performed based on the status of the indoor units of the multi-split air conditioner, improving the overall performance of the air conditioner.

Description

Technical Field

[0001] This invention belongs to the field of air treatment technology, specifically, it relates to air conditioner noise treatment technology, and more specifically, it relates to a noise control method for multi-split air conditioners. Background Technology

[0002] Air conditioners utilize a refrigerant circulation system consisting of a compressor, indoor heat exchanger, outdoor heat exchanger, and throttling device. By circulating the refrigerant, they perform functions such as cooling, heating, and dehumidification, thereby regulating indoor air and providing a comfortable environment for people indoors.

[0003] While air conditioners can regulate indoor comfort, they also generate noise during operation, causing indoor noise pollution. To reduce noise pollution, existing air conditioners employ certain noise control strategies. Chinese patent application CN106556122A discloses a sleep control method for an air conditioner, which reduces noise by lowering the fan speed when indoor noise levels exceed acceptable limits. During the fan speed reduction process, the set temperature is also adjusted to maintain a constant cooling capacity, providing a comfortable sleeping environment.

[0004] While existing air conditioners can reduce noise and improve comfort by adjusting operating parameters such as fan speed and set temperature, their solutions are only suitable for single-split air conditioners and are not well-suited for multi-split air conditioners. Summary of the Invention

[0005] The purpose of this invention is to provide a noise control method for multi-split air conditioners. This method executes air conditioner control based on the status of the indoor unit of the multi-split air conditioner, thereby improving the overall performance of the air conditioner.

[0006] To achieve the above-mentioned objectives, the present invention employs the following technical solution:

[0007] A noise control method for a multi-split air conditioner, the multi-split air conditioner including an outdoor unit and multiple indoor units, the method comprising:

[0008] When the air conditioner is running in cooling mode, it obtains the real-time noise level of the indoor environment where the selected indoor unit is located and the real-time operating load of all indoor units.

[0009] When the real-time noise value is greater than the real-time noise threshold, the following noise reduction control is performed:

[0010] When the real-time operating load is greater than the set operating load, at least the operating parameters of the selected indoor unit and the operating parameters of other indoor units in operation are controlled to reduce the noise generated by the selected indoor unit.

[0011] When the real-time operating load is not greater than the set operating load, the operating parameters of the other indoor units in operation are kept unchanged, and at least the operating parameters of the selected indoor unit are controlled to reduce the noise generated by the selected indoor unit.

[0012] In one preferred embodiment, when the real-time operating load is not greater than the set operating load, at least the operating parameters of the selected indoor unit are controlled, specifically including:

[0013] The fan speed of the selected indoor unit before it slows down is obtained and used as the initial speed.

[0014] Control the fan speed of the selected indoor unit to decrease from the initial speed;

[0015] The real-time speed reduction variation of the fan speed of the selected indoor unit is obtained, and the real-time operating parameter control strategy is determined based on the known correspondence between the speed reduction variation and the parameter control strategy.

[0016] The operating parameters of the selected indoor unit are controlled according to the real-time operating parameter control strategy.

[0017] In one preferred embodiment, the correspondence between the deceleration variation and the parameter control strategy includes:

[0018] The speed reduction variation is not greater than the first set variation, and the parameter control strategy is the first control strategy;

[0019] The deceleration variation is greater than the first set variation but not greater than the second set variation, and the parameter control strategy is the second control strategy; the second set variation is greater than the first set variation.

[0020] The first control strategy includes:

[0021] Continue to reduce the fan speed of the indoor unit until the speed reduction change reaches the first set change amount;

[0022] The second control strategy includes:

[0023] Obtain the first temperature difference between the indoor unit's air outlet after and before the speed reduction;

[0024] When the first temperature difference is not greater than the first temperature difference threshold, the target superheat of the indoor unit remains unchanged;

[0025] When the first temperature difference is greater than the first temperature difference threshold, the target superheat is reduced, and the air outlet angle of the indoor unit is controlled to the first set angle.

[0026] In one preferred embodiment, when the real-time start-up load is not greater than the set start-up load, the process further includes controlling the parameters of the refrigerant circulation system;

[0027] The correspondence between the speed reduction variation and the parameter control strategy also includes:

[0028] If the speed reduction change is greater than the second set change, the parameter control strategy is the third control strategy.

[0029] The third control strategy includes:

[0030] Obtain the second temperature difference between the indoor unit's air outlet after and before the speed reduction;

[0031] When the second temperature difference is not greater than the second temperature difference threshold, the target superheat is reduced;

[0032] When the second temperature difference is greater than the second temperature difference threshold, the target superheat is reduced, the air outlet angle is controlled to the first set angle, the target low pressure is reduced, and the subcooler bypass valve in the refrigerant circulation system is opened.

[0033] The second temperature difference threshold is less than the first temperature difference threshold.

[0034] In one preferred embodiment, the third control strategy further includes:

[0035] The target subcooling degree is determined based on the real-time outdoor ambient temperature, and the opening degree of the subcooler bypass valve is controlled based on the target subcooling degree.

[0036] Determining the target supercooling based on the real-time outdoor ambient temperature specifically includes:

[0037] When the real-time outdoor ambient temperature is not greater than the first ambient temperature threshold, the target supercooling is the first target value;

[0038] When the real-time outdoor temperature is not less than the second ambient temperature threshold, the target supercooling is the second target value;

[0039] When the real-time outdoor ambient temperature is greater than the first ambient temperature threshold and less than the second ambient temperature threshold, the target supercooling is between the first target value and the second target value;

[0040] The second ambient temperature threshold is greater than the first ambient temperature threshold, and the second target value is greater than the first target value.

[0041] In one preferred embodiment, when the real-time operating load is greater than the set operating load, at least the operating parameters of the selected indoor unit and the operating parameters of other indoor units in operation are controlled, specifically including:

[0042] The fan speed of the selected indoor unit before it slows down is obtained and used as the initial speed.

[0043] Control the fan speed of the selected indoor unit to decrease from the initial speed;

[0044] The real-time speed reduction variation of the fan speed of the selected indoor unit is obtained, and the real-time operating parameter control strategy is determined based on the known correspondence between the speed reduction variation and the parameter control strategy.

[0045] The operating parameters of the selected indoor unit and the operating parameters of other indoor units in operation are controlled according to the real-time operating parameter control strategy.

[0046] In one preferred embodiment, the correspondence between the deceleration variation and the parameter control strategy includes:

[0047] The speed reduction variation is not greater than the third preset variation, and the parameter control strategy is the fourth control strategy.

[0048] The deceleration variation is greater than the third set variation but not greater than the fourth set variation, and the parameter control strategy is the fifth control strategy; the fourth set variation is greater than the third set variation.

[0049] The fourth control strategy includes:

[0050] Continue to reduce the fan speed of the selected indoor unit until the speed reduction change reaches the third set change amount;

[0051] The fifth control strategy includes:

[0052] Obtain the third temperature difference between the indoor unit's air outlet after and before the speed reduction;

[0053] When the third temperature difference is not greater than the third temperature difference threshold, the target superheat of all indoor units remains unchanged;

[0054] When the third temperature difference is greater than the third temperature difference threshold, the target superheat of the selected indoor unit is reduced, the target superheat of other indoor units in operation is increased, and the air outlet angle of the selected indoor unit is controlled to the second set angle.

[0055] In one preferred embodiment, when the real-time start-up load is greater than the set start-up load, the process further includes controlling the parameters of the refrigerant circulation system.

[0056] The correspondence between the speed reduction variation and the parameter control strategy also includes:

[0057] If the speed reduction change is greater than the fourth set change, the parameter control strategy is the sixth control strategy.

[0058] The sixth control strategy includes:

[0059] Obtain the fourth temperature difference between the indoor unit's air outlet after and before the speed reduction;

[0060] When the fourth temperature difference is not greater than the fourth temperature difference threshold, the target superheat of the selected indoor unit is reduced;

[0061] When the fourth temperature difference is greater than the fourth temperature difference threshold, the target superheat of the selected indoor unit is reduced, the target superheat of other indoor units in operation is increased, the air outlet angle of the selected indoor unit is controlled to the second set angle, the target low pressure is reduced, and the subcooler bypass valve in the refrigerant circulation system is opened.

[0062] The fourth temperature difference threshold is less than the third temperature difference threshold.

[0063] In one preferred embodiment, the sixth control strategy further includes:

[0064] The target subcooling degree is determined based on the real-time outdoor ambient temperature, and the opening degree of the subcooler bypass valve is controlled based on the target subcooling degree.

[0065] Determining the target supercooling based on the real-time outdoor ambient temperature specifically includes:

[0066] When the real-time outdoor ambient temperature is not greater than the third ambient temperature threshold, the target supercooling is the third target value;

[0067] When the real-time outdoor temperature is not less than the fourth ambient temperature threshold, the target supercooling is the fourth target value;

[0068] When the real-time outdoor ambient temperature is greater than the third ambient temperature threshold and less than the fourth ambient temperature threshold, the target supercooling is between the third target value and the fourth target value;

[0069] The fourth ambient temperature threshold is greater than the third ambient temperature threshold, and the fourth target value is greater than the third target value.

[0070] In one preferred embodiment, the real-time noise threshold is a dynamically variable value and is determined using the following method:

[0071] The real-time time and the type of room where the selected indoor unit is located are obtained. Based on the real-time time, the type of room where the selected indoor unit is located, and the known correspondence between time, room type and noise threshold, the real-time noise threshold is determined.

[0072] Compared with the prior art, the advantages and positive effects of the present invention are as follows: The noise control method for multi-split air conditioners provided by the present invention executes corresponding control strategies based on the real-time noise value of the indoor environment and the operating load status of the indoor units during the cooling operation of the air conditioner, thereby reducing indoor noise while meeting the cooling demand as much as possible; moreover, it can achieve differentiated noise reduction control, avoiding the problem that it is difficult to balance noise reduction and air conditioning effects when executing the same control under different indoor unit operating loads, which is conducive to balancing noise reduction performance and air conditioning performance, thereby improving the overall operating performance of the air conditioner.

[0073] Other features and advantages of the present invention will become clearer after reading the detailed embodiments of the invention in conjunction with the accompanying drawings. Attached Figure Description

[0074] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0075] Figure 1 This is a flowchart of an embodiment of the noise control method for multi-split air conditioners of the present invention;

[0076] Figure 2 This is a flowchart of one embodiment of the noise control method for multi-split air conditioners of the present invention under a start-up load state;

[0077] Figure 3 A flowchart of another specific embodiment of the noise control method for multi-split air conditioners of the present invention under a start-up load state;

[0078] Figure 4 This is a flowchart of one embodiment of the noise control method for multi-split air conditioners of the present invention under another operating load state;

[0079] Figure 5 The flowchart shows another specific embodiment of the noise control method for multi-split air conditioners of the present invention under another operating load condition. Detailed Implementation

[0080] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0081] The technical solutions of the various embodiments of the present invention can be combined with each other, but must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0082] Figure 1 The diagram shows a flowchart of an embodiment of the noise control method for a multi-split air conditioner according to the present invention. This embodiment of the multi-split air conditioner has one outdoor unit and multiple indoor units. The multiple indoor units are respectively installed in different indoor environments and are connected to the outdoor unit in parallel throughout the refrigerant circulation system, forming a multi-split air conditioner with one unit supporting multiple units.

[0083] like Figure 1 As shown, this embodiment uses the following process to achieve noise reduction control for a selected indoor unit:

[0084] Step 10: When the air conditioner is running in cooling mode, obtain the real-time noise level of the indoor environment where the selected indoor unit is located and the real-time operating load of all indoor units.

[0085] The selected indoor unit refers to the indoor unit for which noise control will be implemented. The real-time noise level of the indoor environment refers to the noise level of the indoor environment where the indoor unit is located, collected in real-time at a known sampling frequency during the air conditioner's cooling operation. To accurately reflect the noise level of the indoor environment caused by the operation of the indoor unit, while avoiding interference from the noise generated by the indoor unit's operation on the test results, it is preferable to collect the ambient sound within a certain range from the indoor unit as the real-time noise level. Specifically, this can be achieved by placing a noise acquisition device at a certain distance from the indoor unit's air outlet, connecting the noise acquisition device to the air conditioner's control board, and transmitting the collected real-time noise information to the control board, thereby obtaining the real-time noise level reflecting the noise level of the indoor environment where the selected indoor unit is located.

[0086] The real-time operating load of the indoor unit is the operating load of the indoor unit determined in real time according to a known sampling frequency. The specific calculation method is as follows: Define the sum of the rated cooling capacities of all indoor units connected to the outdoor unit that are in the operating state as Q1, and define the sum of the rated cooling capacities of all indoor units connected to the outdoor unit as Q2. Then the operating load X = Q1 / Q2.

[0087] Step 20: When the real-time noise value is greater than the real-time noise threshold, perform noise reduction control.

[0088] The real-time noise threshold is a determinable value that reflects whether indoor environmental noise exceeds the standard. The real-time noise threshold can be a fixed value. In some other preferred embodiments, the real-time noise threshold is a dynamically variable value. Furthermore, the real-time noise threshold is determined using the following method:

[0089] During the air conditioner noise control process, the real-time time and the type of room where the selected indoor unit is located are acquired. Then, based on the real-time time, the type of room where the selected indoor unit is located, and the known correspondence between time, room type, and noise threshold, the real-time noise threshold is determined. The correspondence between time, room type, and noise threshold is known and preset in the air conditioner's memory and / or controller. Specifically, this correspondence can be determined based on existing residential environmental noise emission standards to meet people's adaptability and acceptability to indoor environmental noise.

[0090] If the real-time noise value is greater than the real-time noise threshold, it indicates that the indoor noise of the selected indoor unit exceeds the standard. Noise reduction control will be implemented on the selected indoor unit to reduce the noise pollution caused by the operation of the indoor unit.

[0091] Furthermore, in multi-split air conditioners, the operation of other indoor units can affect the refrigerant circulation system, thereby impacting the cooling performance of the selected indoor unit. Therefore, this embodiment implements different noise reduction control strategies in steps 30 and 40 based on the real-time operating load.

[0092] Step 30: When the real-time operating load is not greater than the set operating load, keep the operating parameters of other indoor units in operation unchanged, and at least control the operating parameters of the selected indoor unit to reduce the noise generated by the selected indoor unit.

[0093] The start-up load is set to a preset known value, which is a threshold value reflecting the degree of impact on the operating effect or performance of the selected indoor unit. In some preferred embodiments, the start-up load is set to 50%.

[0094] When the real-time operating load is no greater than the set operating load, the impact of other indoor units on the selected indoor unit is minimal. In this case, the operating parameters of the other indoor units in operation are kept constant, while the operating parameters of the selected indoor unit are controlled. Alternatively, the operating parameters of the selected indoor unit and the refrigerant circulation system parameters are controlled to reduce the noise generated by the selected indoor unit.

[0095] Step 40: When the real-time operating load is greater than the set operating load, at least the operating parameters of the selected indoor unit and the operating parameters of other indoor units in operation should be controlled to reduce the noise generated by the selected indoor unit.

[0096] When the real-time operating load exceeds the set operating load, other indoor units have a significant impact on the selected indoor unit. In this case, the operating parameters of the selected indoor unit and the operating parameters of other indoor units in operation are controlled, or the operating parameters of the selected indoor unit, the operating parameters of other indoor units in operation, and the refrigerant circulation system parameters are all controlled to reduce the noise generated by the selected indoor unit.

[0097] In this embodiment, when the air conditioner is running in cooling mode, a corresponding control strategy is executed based on the real-time noise level of the indoor environment and the operating load status of the indoor unit. By reasonably selecting the control strategy, it is easy to meet the cooling demand as much as possible while reducing indoor noise. Moreover, it can achieve differentiated noise reduction control, avoiding the problem that it is difficult to balance noise reduction and air conditioning effects when executing the same control under different indoor unit operating loads. This helps to balance noise reduction performance and air conditioning performance, thereby improving the overall operating performance of the air conditioner.

[0098] Figure 2 The flowchart shown is an embodiment of the noise control method for multi-split air conditioners of the present invention under a certain operating load state. Specifically, it is a flowchart of an embodiment when the real-time operating load is not greater than the set operating load.

[0099] like Figure 2 As shown, this embodiment uses the following process to achieve noise reduction control for a selected indoor unit:

[0100] Step 31: Obtain the fan speed of the selected indoor unit before it slows down as the initial speed, and control the fan speed of the selected indoor unit to slow down from the initial speed.

[0101] The noise generated by the indoor unit's fan is a major source of indoor environmental noise. Therefore, in this embodiment, noise reduction is achieved by lowering the indoor unit's fan speed. Furthermore, the initial speed is taken as the speed at which noise reduction control is to be implemented but before the speed is reduced, and the speed reduction begins from the initial speed.

[0102] Step 32: Obtain the real-time speed reduction variation of the selected indoor unit's fan speed, and determine the real-time operating parameter control strategy based on the known correspondence between the speed reduction variation and the parameter control strategy.

[0103] In this embodiment, a method of gradually reducing the rotational speed and implementing different control strategies for different speed variations is adopted to avoid sudden or excessive speed changes affecting the cooling effect and the operational stability of the cooling system. Specifically, during the noise reduction control process, real-time rotational speed values ​​are acquired at a set frequency, and the real-time speed reduction variation is determined based on the initial speed and the real-time speed values. A pre-set correspondence between the speed reduction variation and parameter control strategies is also provided, which includes at least the relationship between the speed reduction variation and the selected indoor unit operating parameters. Then, the real-time operating parameter control strategy is determined based on the real-time speed reduction variation.

[0104] Step 33: Control the operating parameters of the selected indoor unit according to the real-time operating parameter control strategy.

[0105] In some other preferred embodiments, the correspondence between the speed reduction variation and the parameter control strategy also includes the relationship between the speed reduction variation and the refrigerant circulation system parameters. Accordingly, when the real-time operating load is not greater than the set operating load, in addition to controlling the operating parameters of the selected indoor unit, the refrigerant circulation system parameters are also controlled to further achieve a balance between noise reduction and air conditioning effects. For the specific control process, see [link to relevant documentation]. Figure 3 Description of the embodiments.

[0106] Figure 3 The flowchart shown is another specific embodiment of the noise control method for multi-split air conditioners of the present invention under a start-up load state. Specifically, it is a flowchart of a specific embodiment in which both the operating parameters of the selected indoor unit and the parameters of the refrigerant circulation system are controlled.

[0107] like Figure 3 As shown, this embodiment uses the following process to achieve noise reduction control:

[0108] Step 321: Obtain the real-time deceleration change.

[0109] As mentioned above, the real-time speed reduction variation is determined based on the initial speed and the real-time speed value. In practical applications, the speed reduction variation can be the amount of speed reduction, the rate of speed reduction, or the gear reduction, etc., and can be defined according to the specific application.

[0110] In a preferred embodiment, to simplify the processing, the speed reduction variation is defined as a reduction in engine speed by a gear. Furthermore, in this embodiment, two preset variations are defined, a first and a second, where the second variation is greater than the first. For example, the first variation might be a reduction of one gear, and the second variation a reduction of two gears. After acquiring the real-time noise reduction variation, it is compared with the first and second preset variations. Based on the comparison result, different control strategies are implemented, resulting in different noise reduction controls.

[0111] Step 322: Determine whether the real-time speed reduction change is greater than the first set change. If yes, proceed to step 324; otherwise, proceed to step 323.

[0112] Step 323: Determine the real-time parameters according to the first control strategy. Then, proceed to step 327.

[0113] In this embodiment, the first control strategy is to continue reducing the fan speed of the indoor unit until the speed reduction change reaches a first set change amount. Accordingly, the determined real-time parameter is to reduce the fan speed of the selected indoor unit until the speed reduction change reaches the first set change amount, so as to improve the noise reduction effect.

[0114] Step 324: Determine whether the real-time deceleration change is greater than the second set change. If yes, proceed to step 326; otherwise, proceed to step 325.

[0115] After determining in step 322 that the real-time speed change is greater than the first set change, it is further determined whether the real-time speed change is greater than the second set change, and different controls are executed according to the determination result.

[0116] Step 325: Determine the real-time parameters according to the second control strategy. Then, proceed to step 327.

[0117] If the real-time speed change is greater than the first set change but not greater than the second set change, the corresponding parameter control strategy is the second control strategy.

[0118] The second control strategy includes:

[0119] Obtain the first temperature difference between the indoor unit's air outlet after and before the speed reduction;

[0120] When the first temperature difference is not greater than the first temperature difference threshold, the target superheat of the indoor unit remains unchanged;

[0121] When the first temperature difference is greater than the first temperature difference threshold, the target superheat is reduced and the air outlet angle of the indoor unit is controlled to the first set angle.

[0122] The first temperature difference is the real-time temperature difference, which is the difference between the temperature of the indoor unit's air outlet after the speed reduction and the temperature of the indoor unit's air outlet before the speed reduction. The temperature of the indoor unit's air outlet can be obtained by setting a temperature acquisition device at the air outlet. The first temperature difference threshold is a preset value, for example, -2℃. The first set angle is a preset value, for example, 45°. At this first set angle, the cold air blown out of the indoor unit's air outlet can be delivered into the room with maximum cooling efficiency.

[0123] If the temperature difference between the indoor unit's air outlet before and after speed reduction is not greater than the first temperature difference threshold, the speed reduction has little impact on the indoor cooling effect. In this case, the target superheat of the indoor unit remains unchanged to maintain the stability of the air conditioner's overall operation. If the temperature difference between the indoor unit's air outlet before and after speed reduction is greater than the first temperature difference threshold, the speed reduction has a significant impact on the indoor cooling effect. In this case, the target superheat of the selected indoor unit is reduced to increase the opening of the electronic expansion valve of the selected indoor unit, increasing the amount of refrigerant entering the selected indoor unit to compensate for the impact of the reduced speed on the cooling effect. At the same time, the air outlet angle of the indoor unit is also controlled to remain at the first set angle to improve the cooling effect.

[0124] Step 326: Determine the real-time parameters according to the third control strategy. Then, proceed to step 328.

[0125] If step 324 determines that the real-time speed change is greater than the second set change, and the speed drop is greater, a third control strategy will be adopted to determine the real-time parameters.

[0126] The third control strategy includes:

[0127] Obtain the second temperature difference between the indoor unit's air outlet after and before the speed reduction;

[0128] When the second temperature difference is not greater than the second temperature difference threshold, reduce the target superheat.

[0129] When the second temperature difference exceeds the second temperature difference threshold, the target superheat is reduced, the outlet air angle is controlled to the first set angle, the target low pressure is lowered, and the subcooler bypass valve in the refrigerant circulation system is opened. The specific location of the subcooler bypass valve in the refrigerant circulation system is existing technology and will not be described in detail here.

[0130] The meaning and acquisition method of the second temperature difference are the same as those of the first temperature difference mentioned above. It is defined as the second temperature difference to distinguish it from the first temperature difference. The second temperature difference threshold is also a preset value, and its value is less than the first temperature difference threshold. The purpose of setting the second temperature difference threshold to be less than the first temperature difference threshold is that the greater the decrease in indoor unit fan speed, the worse the cooling capacity, and the more necessary it is to adjust the cooling capacity.

[0131] If the temperature difference between the indoor unit's air outlet and its initial temperature before speed reduction is not greater than the second temperature difference threshold, the target superheat of the selected indoor unit is further reduced, and the amount of refrigerant entering the selected indoor unit is increased to compensate for the impact of the reduced speed on the cooling effect. If the temperature difference between the indoor unit's air outlet and its initial temperature before speed reduction is greater than the second temperature difference threshold, and the speed reduction has a significant impact on the indoor cooling effect, then not only is the target superheat of the selected indoor unit reduced, and the air outlet angle of the selected indoor unit controlled to achieve control of the selected indoor unit's operating parameters, but the parameters of the refrigerant circulation system are also controlled. Specifically, the target low pressure is reduced to increase the compressor's operating speed, increase the refrigerant circulation, and further enhance the cooling capacity of the selected indoor unit; at the same time, the subcooler bypass valve in the refrigerant circulation system is opened to increase the subcooling of the refrigerant, further enhancing the cooling capacity of the refrigerant entering the selected indoor unit and improving the compensation effect for the decrease in cooling performance caused by the significant reduction in speed.

[0132] In some other preferred embodiments, the third control strategy further includes:

[0133] The target subcooling is determined based on the real-time outdoor ambient temperature, and the opening of the subcooler bypass valve is controlled based on the target subcooling to ensure that the refrigerant circulation system can operate stably and safely under different outdoor ambient temperatures.

[0134] The target supercooling is determined based on the real-time outdoor ambient temperature, specifically including:

[0135] When the real-time outdoor ambient temperature is not greater than the first ambient temperature threshold, the target supercooling is the first target value;

[0136] When the real-time outdoor temperature is not less than the second ambient temperature threshold, the target supercooling is the second target value;

[0137] When the real-time outdoor ambient temperature is greater than the first ambient temperature threshold and less than the second ambient temperature threshold, the target supercooling is between the first target value and the second target value.

[0138] Wherein, the second ambient temperature threshold is greater than the first ambient temperature threshold, and the second target value is greater than the first target value. Preferably, the first ambient temperature threshold is 20℃, the second ambient temperature threshold is 35℃, the first target value is 15℃, and the second target value is 30℃.

[0139] Step 327: Select the indoor unit based on real-time parameters.

[0140] After determining the real-time parameters according to the first control strategy in step 323, or after determining the real-time parameters according to the second control strategy in step 325, the indoor unit is selected according to the real-time parameters to perform noise reduction control.

[0141] Step 328: Select the indoor unit and refrigerant circulation system based on real-time parameters.

[0142] Step 326: The real-time parameters determined by the third control strategy include both the operating parameters of the selected indoor unit and the control parameters of the refrigerant circulation system. Then, the selected indoor unit and the refrigerant circulation system are controlled according to the real-time parameters to achieve noise reduction control of the selected indoor unit.

[0143] It should be understood that during the process of controlling the operation of the air conditioner according to the real-time parameters determined by a certain control strategy, the real-time noise value of the indoor environment where the selected indoor unit is located is continuously acquired. If the real-time noise value is not greater than the real-time noise threshold, the current control strategy is maintained.

[0144] Figure 4 The flowchart illustrates an embodiment of the noise control method for multi-split air conditioners of the present invention under another operating load condition, specifically, a flowchart of an embodiment when the real-time operating load is greater than the set operating load.

[0145] like Figure 4 As shown, this embodiment uses the following process to achieve noise reduction control for a selected indoor unit:

[0146] Step 41: Obtain the fan speed of the selected indoor unit before it slows down as the initial speed, and control the fan speed of the selected indoor unit to slow down from the initial speed.

[0147] The noise generated by the indoor unit's fan is a major source of indoor environmental noise. Therefore, in this embodiment, noise reduction is achieved by lowering the indoor unit's fan speed. Furthermore, the initial speed is taken as the speed at which noise reduction control is to be implemented but before the speed is reduced, and the speed reduction begins from the initial speed.

[0148] Step 42: Obtain the real-time speed reduction variation of the selected indoor unit's fan speed, and determine the real-time operating parameter control strategy based on the known correspondence between the speed reduction variation and the parameter control strategy.

[0149] In this embodiment, a method of gradually reducing the rotational speed and implementing different control strategies for different speed variations is adopted to avoid sudden or excessive speed changes affecting the cooling effect and the operational stability of the cooling system. Specifically, during the noise reduction control process, real-time rotational speed values ​​are acquired at a set frequency, and the real-time speed reduction variation is determined based on the initial speed and the real-time speed values. A pre-set correspondence between the speed reduction variation and parameter control strategies is also provided, and, as... Figure 1 As described in the embodiment, when the starting load exceeds the set starting load, at least the operating parameters of the selected indoor unit and the operating parameters of other indoor units in operation are controlled. Therefore, the correspondence between the speed reduction variation and the parameter control strategy includes at least the relationship between the speed reduction variation and the operating parameters of the selected indoor unit, as well as the relationship with the operating parameters of other indoor units in operation. Then, a real-time operating parameter control strategy is determined based on the real-time speed reduction variation.

[0150] Step 43: Control the operating parameters of the selected indoor unit and other indoor units in operation according to the real-time operating parameter control strategy.

[0151] In some other preferred embodiments, the correspondence between the speed reduction variation and the parameter control strategy also includes the relationship between the speed reduction variation and the refrigerant circulation system parameters. Accordingly, when the real-time operating load exceeds the set operating load, in addition to controlling the operating parameters of the selected indoor unit and other indoor units in operation, the refrigerant circulation system parameters are also controlled to further balance noise reduction and air conditioning effects. For the specific control process, see [link to relevant documentation]. Figure 5 Description of the embodiments.

[0152] Figure 5 The flowchart illustrates another specific embodiment of the noise control method for multi-split air conditioners of the present invention under another operating load state. Specifically, it is a flowchart of a specific embodiment in which the operating parameters of the selected indoor unit, the indoor unit in other operating states, and the refrigerant circulation system parameters are all controlled.

[0153] like Figure 5 As shown, this embodiment uses the following process to achieve noise reduction control:

[0154] Step 421: Obtain the real-time deceleration change.

[0155] As mentioned above, the real-time speed reduction variation is determined based on the initial speed and the real-time speed value. In practical applications, the speed reduction variation can be the amount of speed reduction, the rate of speed reduction, or the gear reduction, etc., and can be defined according to the specific application.

[0156] In a preferred embodiment, to simplify the processing, the speed reduction variation is defined as the speed reduction gear. Furthermore, in this embodiment, two preset variation values ​​are provided: a third preset variation value and a fourth preset variation value, where the fourth preset variation value is greater than the third preset variation value. The third preset variation value can be the same as the aforementioned first preset variation value, and the fourth preset variation value can be the same as the aforementioned second preset variation value; alternatively, they can be different or not entirely the same. For example, the third preset variation value may be a reduction of one gear, and the fourth preset variation value may be a reduction of two gears. After obtaining the real-time noise reduction variation value, it is compared with the third and fourth preset variation values. Based on the comparison result, different control strategies are implemented, resulting in different noise reduction controls.

[0157] Step 422: Determine whether the real-time speed reduction change is greater than the third preset change. If yes, proceed to step 424; otherwise, proceed to step 423.

[0158] Step 423: Determine the real-time parameters according to the fourth control strategy. Then, proceed to step 427.

[0159] In this embodiment, the fourth control strategy is to continue reducing the fan speed of the selected indoor unit until the speed reduction change reaches the third preset change amount. Accordingly, the determined real-time parameter is to reduce the fan speed of the selected indoor unit until the speed reduction change reaches the third preset change amount, so as to improve the noise reduction effect.

[0160] Step 424: Determine whether the real-time deceleration change is greater than the fourth preset change. If yes, proceed to step 426; otherwise, proceed to step 425.

[0161] After determining in step 422 that the real-time speed change is greater than the third set change, it is further determined whether the real-time speed change is greater than the fourth set change, and different controls are executed according to the determination result.

[0162] Step 425: Determine the real-time parameters according to the fifth control strategy. Then, proceed to step 427.

[0163] If the real-time speed change is greater than the third set change but not greater than the fourth set change, the corresponding parameter control strategy is the fifth control strategy.

[0164] The fifth control strategy includes:

[0165] Obtain the third temperature difference between the indoor unit's air outlet after and before the speed reduction;

[0166] When the third temperature difference is not greater than the third temperature difference threshold, the target superheat of all indoor units remains unchanged;

[0167] When the third temperature difference is greater than the third temperature difference threshold, the target superheat of the selected indoor unit is reduced, the target superheat of other indoor units in operation is increased, and the air outlet angle of the selected indoor unit is controlled to the second set angle.

[0168] The meaning and acquisition method of the third temperature difference are the same as those of the first and second temperature differences. The threshold value of the third temperature difference is also a preset value, for example, -2℃. The second set angle is a preset value, for example, 45°. Under this second set angle, the cold air blown out of the indoor unit's air outlet can be delivered into the room with maximum cooling efficiency.

[0169] If the temperature difference between the indoor unit's air outlet after and before speed reduction is not greater than the third temperature difference threshold, the speed reduction has little impact on the indoor cooling effect. In this case, the target superheat of all indoor units remains unchanged to maintain the stability of the entire air conditioner's operation. If the temperature difference between the indoor unit's air outlet after and before speed reduction is greater than the third temperature difference threshold, the speed reduction has a significant impact on the indoor cooling effect. In this case, the target superheat of the selected indoor unit is reduced to increase the opening of the electronic expansion valve of the selected indoor unit, increasing the amount of refrigerant entering the selected indoor unit to compensate for the impact of the reduced speed on the cooling effect. The target superheat of other indoor units in operation is also increased to reduce the amount of refrigerant entering other indoor units, stabilizing the operation of the entire system and allowing more refrigerant to enter the selected indoor unit. Simultaneously, the air outlet angle of the selected indoor unit is controlled to remain at the second set angle to improve the cooling effect.

[0170] Step 426: Determine the real-time parameters according to the sixth control strategy. Then, proceed to step 428.

[0171] If step 424 determines that the real-time speed change is greater than the fourth set change, and the speed drop is greater, the sixth control strategy will be used to determine the real-time parameters.

[0172] The sixth control strategy includes:

[0173] Obtain the fourth temperature difference between the indoor unit's air outlet after and before the speed reduction;

[0174] When the fourth temperature difference is not greater than the fourth temperature difference threshold, reduce the target superheat of the selected indoor unit;

[0175] When the fourth temperature difference exceeds the fourth temperature difference threshold, the target superheat of the selected indoor unit is reduced, the target superheat of other indoor units in operation is increased, the air outlet angle of the selected indoor unit is controlled to the second set angle, the target low pressure is reduced, and the subcooler bypass valve in the refrigerant circulation system is opened. The specific location of the subcooler bypass valve in the refrigerant circulation system is existing technology and will not be described in detail here.

[0176] The meaning and acquisition method of the fourth temperature difference are the same as those of the third temperature difference mentioned above. It is defined as the fourth temperature difference to distinguish it from the third temperature difference. The threshold value of the fourth temperature difference is also a preset value, and its value is less than the threshold value of the third temperature difference. The purpose of setting the fourth temperature difference threshold to be less than the third temperature difference threshold is that the greater the decrease in indoor unit fan speed, the worse the cooling capacity, and the more necessary it is to adjust the cooling capacity.

[0177] If the temperature difference between the indoor unit's air outlet and its initial temperature before speed reduction is not greater than the fourth temperature difference threshold, the target superheat of the selected indoor unit is further reduced, and the amount of refrigerant entering the selected indoor unit is increased to compensate for the impact of the reduced speed on the cooling effect. If the temperature difference between the indoor unit's air outlet and its initial temperature before speed reduction is greater than the fourth temperature difference threshold, and the speed reduction has a significant impact on the indoor cooling effect, then not only is the target superheat of the selected indoor unit reduced, and the air outlet angle of the selected indoor unit controlled, but the target superheat of other indoor units in operation is also increased to control the operating parameters of the selected indoor unit and other indoor units in operation. Furthermore, the parameters of the refrigerant circulation system are also controlled. Specifically, the target low pressure is reduced to increase the compressor's operating speed, increase refrigerant circulation, and further enhance the cooling capacity of the selected indoor unit. Simultaneously, the subcooler bypass valve in the refrigerant circulation system is opened to increase the subcooling of the refrigerant, further enhancing the cooling capacity of the refrigerant entering the selected indoor unit and improving the compensation effect for the decrease in cooling performance caused by the significant reduction in speed.

[0178] In some other preferred embodiments, the sixth control strategy further includes:

[0179] The target subcooling is determined based on the real-time outdoor ambient temperature, and the opening of the subcooler bypass valve is controlled based on the target subcooling to ensure that the refrigerant circulation system can operate stably and safely under different outdoor ambient temperatures.

[0180] The target supercooling is determined based on the real-time outdoor ambient temperature, specifically including:

[0181] When the real-time outdoor ambient temperature is not greater than the first ambient temperature threshold, the target supercooling is the first target value;

[0182] When the real-time outdoor temperature is not less than the second ambient temperature threshold, the target supercooling is the second target value;

[0183] When the real-time outdoor ambient temperature is greater than the first ambient temperature threshold and less than the second ambient temperature threshold, the target supercooling is between the first target value and the second target value.

[0184] Wherein, the second ambient temperature threshold is greater than the first ambient temperature threshold, and the second target value is greater than the first target value. Preferably, the first ambient temperature threshold is 20℃, the second ambient temperature threshold is 35℃, the first target value is 15℃, and the second target value is 30℃.

[0185] Step 427: Control the selected indoor unit and other indoor units that are in operation based on real-time parameters.

[0186] After determining the real-time parameters according to the fourth control strategy in step 423, or after determining the real-time parameters according to the fifth control strategy in step 425, the selected indoor unit and other indoor units in operation are controlled according to the real-time parameters to perform noise reduction control.

[0187] Step 428: Control the selected indoor unit, other indoor units in operation, and the refrigerant circulation system according to real-time parameters.

[0188] Step 426: The real-time parameters determined by the sixth control strategy include the operating parameters of the selected indoor unit and the operating parameters of other indoor units in operation, as well as the control parameters of the refrigerant circulation system. Then, the selected indoor unit, other indoor units in operation, and the refrigerant circulation system are controlled according to the real-time parameters to achieve noise reduction control of the selected indoor unit.

[0189] It should be understood that during the process of controlling the operation of the air conditioner according to the real-time parameters determined by a certain control strategy, the real-time noise value of the indoor environment where the selected indoor unit is located is continuously acquired. If the real-time noise value is not greater than the real-time noise threshold, the current control strategy is maintained.

[0190] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions claimed by the present invention.

Claims

1. A noise control method for a multi-split air conditioner, wherein the multi-split air conditioner includes an outdoor unit and multiple indoor units, characterized in that, The method includes: When the air conditioner is running in cooling mode, it obtains the real-time noise level of the indoor environment where the selected indoor unit is located and the real-time operating load of all indoor units. When the real-time noise value is greater than the real-time noise threshold, the following noise reduction control is performed: When the real-time operating load is greater than the set operating load, at least the fan speed of the selected indoor unit is reduced and the operating parameters of other indoor units in operation are controlled to reduce the noise generated by the selected indoor unit; When the real-time operating load is not greater than the set operating load, the operating parameters of the other indoor units in operation are kept unchanged, and the fan speed of the selected indoor unit is reduced to reduce the noise generated by the selected indoor unit. When the real-time operating load exceeds the set operating load, at least the fan speed of the selected indoor unit is reduced and the operating parameters of other indoor units in operation are controlled, specifically including: The fan speed of the selected indoor unit before it slows down is obtained and used as the initial speed. Control the fan speed of the selected indoor unit to decrease from the initial speed; The real-time speed reduction variation of the fan speed of the selected indoor unit is obtained, and the real-time operating parameter control strategy is determined based on the known correspondence between the speed reduction variation and the parameter control strategy. The operating parameters of the selected indoor unit and the operating parameters of other indoor units in operation are controlled according to the real-time operating parameter control strategy.

2. The noise control method for multi-split air conditioners according to claim 1, characterized in that, When the real-time operating load is not greater than the set operating load, at least the fan speed of the selected indoor unit shall be reduced, specifically including: The fan speed of the selected indoor unit before it slows down is obtained and used as the initial speed. Control the fan speed of the selected indoor unit to decrease from the initial speed; The real-time speed reduction variation of the fan speed of the selected indoor unit is obtained, and the real-time operating parameter control strategy is determined based on the known correspondence between the speed reduction variation and the parameter control strategy. The operating parameters of the selected indoor unit are controlled according to the real-time operating parameter control strategy.

3. The noise control method for multi-split air conditioners according to claim 2, characterized in that, The correspondence between the speed reduction variation and the parameter control strategy includes: The speed reduction variation is not greater than the first set variation, and the parameter control strategy is the first control strategy; The deceleration variation is greater than the first set variation but not greater than the second set variation, and the parameter control strategy is the second control strategy; the second set variation is greater than the first set variation. The first control strategy includes: Continue to reduce the fan speed of the selected indoor unit until the speed reduction change reaches the first set change amount; The second control strategy includes: Obtain the first temperature difference between the selected indoor unit air outlet after and before the speed reduction; When the first temperature difference is not greater than the first temperature difference threshold, the target superheat of the selected indoor unit remains unchanged; When the first temperature difference is greater than the first temperature difference threshold, the target superheat is reduced, and the air outlet angle of the selected indoor unit is controlled to the first set angle.

4. The noise control method for multi-split air conditioners according to claim 3, characterized in that, When the real-time start-up load is not greater than the set start-up load, the process also includes controlling the parameters of the refrigerant cycle system. The correspondence between the speed reduction variation and the parameter control strategy also includes: If the speed reduction change is greater than the second set change, the parameter control strategy is the third control strategy. The third control strategy includes: Obtain the second temperature difference between the selected indoor unit air outlet after and before the speed reduction; When the second temperature difference is not greater than the second temperature difference threshold, the target superheat is reduced; When the second temperature difference is greater than the second temperature difference threshold, the target superheat is reduced, the air outlet angle is controlled to the first set angle, the target low pressure is reduced, and the subcooler bypass valve in the refrigerant circulation system is opened. The second temperature difference threshold is less than the first temperature difference threshold.

5. The noise control method for multi-split air conditioners according to claim 4, characterized in that, The third control strategy also includes: The target subcooling degree is determined based on the real-time outdoor ambient temperature, and the opening degree of the subcooler bypass valve is controlled based on the target subcooling degree. Determining the target supercooling based on the real-time outdoor ambient temperature specifically includes: When the real-time outdoor ambient temperature is not greater than the first ambient temperature threshold, the target supercooling is the first target value; When the real-time outdoor temperature is not less than the second ambient temperature threshold, the target supercooling is the second target value; When the real-time outdoor ambient temperature is greater than the first ambient temperature threshold and less than the second ambient temperature threshold, the target supercooling is between the first target value and the second target value; The second ambient temperature threshold is greater than the first ambient temperature threshold, and the second target value is greater than the first target value.

6. The noise control method for multi-split air conditioners according to claim 1, characterized in that, The correspondence between the speed reduction variation and the parameter control strategy includes: The speed reduction variation is not greater than the third preset variation, and the parameter control strategy is the fourth control strategy. The deceleration variation is greater than the third set variation but not greater than the fourth set variation, and the parameter control strategy is the fifth control strategy; the fourth set variation is greater than the third set variation. The fourth control strategy includes: Continue to reduce the fan speed of the selected indoor unit until the speed reduction change reaches the third set change amount; The fifth control strategy includes: Obtain the third temperature difference between the selected indoor unit air outlet after and before the speed reduction; When the third temperature difference is not greater than the third temperature difference threshold, the target superheat of all indoor units remains unchanged; When the third temperature difference is greater than the third temperature difference threshold, the target superheat of the selected indoor unit is reduced, the target superheat of other indoor units in operation is increased, and the air outlet angle of the selected indoor unit is controlled to the second set angle.

7. The noise control method for multi-split air conditioners according to claim 6, characterized in that, When the real-time start-up load is greater than the set start-up load, the process also includes controlling the parameters of the refrigerant circulation system. The correspondence between the speed reduction variation and the parameter control strategy also includes: If the speed reduction change is greater than the fourth set change, the parameter control strategy is the sixth control strategy. The sixth control strategy includes: Obtain the fourth temperature difference between the selected indoor unit air outlet before and after the speed reduction; When the fourth temperature difference is not greater than the fourth temperature difference threshold, the target superheat of the selected indoor unit is reduced; When the fourth temperature difference is greater than the fourth temperature difference threshold, the target superheat of the selected indoor unit is reduced, the target superheat of other indoor units in operation is increased, the air outlet angle of the selected indoor unit is controlled to the second set angle, the target low pressure is reduced, and the subcooler bypass valve in the refrigerant circulation system is opened. The fourth temperature difference threshold is less than the third temperature difference threshold.

8. The noise control method for a multi-split air conditioner according to claim 7, characterized in that, The sixth control strategy also includes: The target subcooling degree is determined based on the real-time outdoor ambient temperature, and the opening degree of the subcooler bypass valve is controlled based on the target subcooling degree. Determining the target supercooling based on the real-time outdoor ambient temperature specifically includes: When the real-time outdoor ambient temperature is not greater than the third ambient temperature threshold, the target supercooling is the third target value; When the real-time outdoor temperature is not less than the fourth ambient temperature threshold, the target supercooling is the fourth target value; When the real-time outdoor ambient temperature is greater than the third ambient temperature threshold and less than the fourth ambient temperature threshold, the target supercooling is between the third target value and the fourth target value; The fourth ambient temperature threshold is greater than the third ambient temperature threshold, and the fourth target value is greater than the third target value.

9. The noise control method for a multi-split air conditioner according to any one of claims 1 to 8, characterized in that, The real-time noise threshold is a dynamically variable value and is determined using the following method: The real-time time and the type of room where the selected indoor unit is located are obtained. Based on the real-time time, the type of room where the selected indoor unit is located, and the known correspondence between time, room type and noise threshold, the real-time noise threshold is determined.

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