Control method and control device of multi-split air conditioner and multi-split air conditioner

Abstract

The invention provides a control method and device of a multi-split air conditioner and the multi-split air conditioner. The control method comprises the steps that the actual superheat degree of a plurality of heat exchangers connected in parallel in the multi-split air conditioner is adjusted according to the target superheat degree; when it is determined that each actual superheat degree reaches the target superheat degree, the outlet temperature of each heat exchanger is obtained; and according to the comparison result of the outlet temperatures of all the heat exchangers, the rotating speed of a fan corresponding to each heat exchanger is controlled and adjusted, so that the outlet temperatures of all the heat exchangers are balanced. According to the control method and device of the multi-split air conditioner and the multi-split air conditioner, the outlet temperatures of all the heat exchangers in the system can be balanced, and therefore the heat exchange efficiency and performance of the whole air conditioner system are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical appliances, and in particular to a control method and a control device for a multi-split air conditioner. Background Art

[0002] Multi-split air conditioners are now widely used because their number of indoor and outdoor units and output capacity can be freely adjusted according to demand. In low-temperature winter environments, the outdoor heat exchanger often becomes frosted due to the demand for heat indoors. This frost reduces the heat exchange efficiency of the outdoor unit, increases energy consumption, and reduces the heating effect of the indoor unit. Currently, due to the large size of the outdoor heat exchanger in a multi-split air conditioner, multiple heat exchanger modules are mostly connected in parallel. The most common method is to use a left-right parallel structure for the heat exchanger, which is controlled separately by multiple electronic expansion valves to achieve flow control for the entire unit. Due to the differences in the outdoor heat exchangers, environmental conditions, and the degree of frost between modules, the control of this multi-heat exchanger structure during the defrost process is particularly important. Summary of the Invention

[0003] The present invention provides a control method, a control device and a multi-split air conditioner, which are used to solve the defects existing in the prior art and achieve the following technical effects: the outlet temperatures of all heat exchangers in the system can be balanced, thereby improving the heat exchange efficiency and performance of the entire air conditioning system.

[0004] A method for controlling a multi-split air conditioner according to a first embodiment of the present invention includes:

[0005] Adjusting the actual superheat of a plurality of heat exchangers connected in parallel in the multi-split air conditioner according to the target superheat;

[0006] Determining that each of the actual superheats reaches the target superheat, then obtaining the outlet temperature of each of the heat exchangers;

[0007] According to the comparison result between the outlet temperatures of each heat exchanger, the rotation speed of the fan corresponding to each heat exchanger is controlled and adjusted so that the outlet temperatures of all the heat exchangers reach a balance.

[0008] According to one embodiment of the present invention, the multi-split air conditioner includes a first heat exchanger and a second heat exchanger connected in parallel, the first heat exchanger is correspondingly installed with a first fan, and the second heat exchanger is correspondingly installed with a second fan;

[0009] The step of controlling and adjusting the speed of the fan corresponding to each heat exchanger according to the comparison result between the outlet temperatures of each heat exchanger so that the outlet temperatures of all the heat exchangers reach a balance specifically includes:

[0010] Obtaining the current operating mode of the multi-split air conditioner;

[0011] Under different current operating modes, according to a comparison result between the first outlet temperature and the second outlet temperature, controlling and adjusting the speed of the first fan and / or the second fan until the difference between the first outlet temperature and the second outlet temperature is within an allowable error range;

[0012] The allowable error range is determined according to the current working mode.

[0013] According to one embodiment of the present invention, the allowable error range includes a cooling error range and a heating error range, and the maximum value of the cooling error range is greater than the maximum value of the heating error range, and the minimum value of the cooling error range is less than the minimum value of the cooling error range.

[0014] According to one embodiment of the present invention, the step of controlling and adjusting the speed of the first fan and / or the second fan according to the comparison result between the first outlet temperature and the second outlet temperature in different current operating modes until the difference between the first outlet temperature and the second outlet temperature is within an allowable error range specifically includes:

[0015] In the heating mode, if it is determined that the difference between the first outlet temperature and the second outlet temperature is less than the heating error range, and the ratio between the actual speed of the first fan and the standard speed is less than the first speed ratio, the speed of the first fan is controlled to increase the first speed value based on the current actual speed, and the speed of the second fan is maintained unchanged.

[0016] According to one embodiment of the present invention, the step of controlling and adjusting the speed of the first fan and / or the second fan according to the comparison result between the first outlet temperature and the second outlet temperature in different current operating modes until the difference between the first outlet temperature and the second outlet temperature is within an allowable error range specifically includes:

[0017] In the heating mode, if it is determined that the difference between the first outlet temperature and the second outlet temperature is greater than the heating error range, and the ratio between the actual speed of the second fan and the standard speed is less than the first speed ratio, the speed of the second fan is controlled to increase the second speed value based on the current actual speed, and the speed of the first fan is maintained unchanged.

[0018] According to one embodiment of the present invention, the step of controlling and adjusting the speed of the first fan and / or the second fan according to the comparison result between the first outlet temperature and the second outlet temperature in different current operating modes until the difference between the first outlet temperature and the second outlet temperature is within an allowable error range specifically includes:

[0019] In the cooling mode, if it is determined that the difference between the first outlet temperature and the second outlet temperature is less than the cooling error range, and the ratio between the actual speed of the first fan and the standard speed is less than the second speed ratio, the speed of the second fan is controlled to increase to a third speed value based on the current actual speed, and the speed of the first fan is maintained unchanged.

[0020] According to one embodiment of the present invention, the step of controlling and adjusting the speed of the first fan and / or the second fan according to the comparison result between the first outlet temperature and the second outlet temperature in different current operating modes until the difference between the first outlet temperature and the second outlet temperature is within an allowable error range specifically includes:

[0021] In the cooling mode, if it is determined that the difference between the first outlet temperature and the second outlet temperature is greater than the cooling error range, and the ratio between the actual speed and the standard speed of the second fan is less than the second speed ratio, the speed of the first fan is controlled to increase to a fourth speed value based on the current actual speed, and the speed of the second fan is maintained unchanged.

[0022] According to one embodiment of the present invention, the further embodiment includes:

[0023] Obtaining a first actual current of the first fan and a second actual current of the second fan, and obtaining a target current;

[0024] According to the ratio of at least one of the first actual current and the second actual current to the target current being greater than the set current ratio, the speed of the fan corresponding to the actual current is kept unchanged.

[0025] According to one embodiment of the present invention, the step of adjusting the actual superheat of the plurality of heat exchangers connected in parallel in the multi-split air conditioner according to the target superheat specifically includes:

[0026] The openings of the electronic expansion valves respectively corresponding to the plurality of heat exchangers are adjusted according to the target superheat.

[0027] According to one embodiment of the present invention, the step of adjusting the openings of the electronic expansion valves corresponding to the plurality of heat exchangers according to the target superheat specifically includes:

[0028] In heating mode, the target superheat is determined according to the range of the outdoor ambient temperature, and the opening of the electronic expansion valve is adjusted according to the target superheat;

[0029] Alternatively, in the cooling mode, the openings of all the electronic expansion valves are controlled to be adjusted to the maximum opening.

[0030] According to one embodiment of the present invention, the step of determining whether each of the actual superheats reaches the target superheat comprises: determining whether each of the actual superheats is equal to the target superheat for three consecutive times.

[0031] A control device for a multi-split air conditioner according to a second embodiment of the present invention includes:

[0032] a first control module, configured to adjust actual superheats of a plurality of heat exchangers connected in parallel within the multi-split air conditioner according to a target superheat;

[0033] an acquisition module, configured to determine that each of the actual superheat degrees reaches the target superheat degree, and then acquire the outlet temperature of each of the heat exchangers;

[0034] The second control module is used to control and adjust the rotation speed of the fan corresponding to each heat exchanger according to the comparison result between the outlet temperatures of each heat exchanger, so that the outlet temperatures of all the heat exchangers are balanced.

[0035] According to an embodiment of the third aspect of the present invention, a multi-split air conditioner includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the control method for the multi-split air conditioner as described in the embodiment of the first aspect of the present invention is implemented.

[0036] Compared with the prior art, the control method of the present invention has at least the following advantages: (1) Improved energy efficiency: By precisely controlling the outlet temperature of the heat exchanger, the air conditioning system is ensured to operate in the optimal working state, thereby improving energy utilization efficiency and reducing unnecessary energy waste. (2) Enhanced system stability: The balanced outlet temperature helps to maintain the stable operation of the air conditioning system, avoids system performance fluctuations caused by temperature fluctuations, and ensures the reliability and durability of the air conditioning system. (3) Extended equipment life: Reducing additional wear and pressure caused by temperature imbalance helps to reduce equipment maintenance costs and extend the service life of key components such as heat exchangers and fans. (4) Improved user comfort: By achieving a more uniform indoor temperature distribution, the comfort of the living or working environment is improved, especially in multi-split air conditioning systems, it can ensure that each area can obtain a suitable temperature. (5) Reduced frosting problems: By optimizing the control strategy, the possibility of frosting on the heat exchanger is reduced, which not only improves the heat exchange efficiency, but also reduces the system shutdown and maintenance frequency caused by frosting. (6) Strong adaptability: The method can adapt to different environmental conditions and working conditions, so that the air conditioning system can maintain efficient operation under various external environments, improving the adaptability and flexibility of the system. (7) Intelligent control: Through real-time monitoring and adjustment, this method demonstrates the advantages of intelligent control, which can automatically respond to system changes and reduce the need for human intervention. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0038] Figure 1 1 is a flow chart of a control method for a multi-split air conditioner provided by the present invention;

[0039] Figure 2 It is a structural schematic diagram of the control device of the multi-split air conditioner provided by the present invention;

[0040] Figure 3 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0041] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0042] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0043] The control method, control device and multi-split air conditioner proposed in the present invention are described below with reference to the accompanying drawings. Before describing the embodiments of the present invention in detail, the entire application scenario is described first. The control method, control device, electronic device and computer-readable storage medium of the multi-split air conditioner in the embodiments of the present invention can be applied to the multi-split air conditioner locally, can be applied to the cloud platform in the Internet field, or other types of cloud platforms in the Internet field, or can also be applied to third-party devices. Among them, third-party devices may include various types such as mobile phones, tablet computers, notebooks, car computers and other smart terminals.

[0044] The following description only takes the control method applicable to a multi-split air conditioner as an example. It should be understood that the control method of the embodiment of the present invention can also be applied to cloud platforms and third-party devices.

[0045] It should also be noted that the control method for a multi-split air conditioner proposed in the present invention is universal, that is, the method is applicable to cooling or heating the multi-split air conditioner in a low-temperature environment or a high-temperature environment.

[0046] like Figure 1 As shown, the control method of the multi-split air conditioner according to the first embodiment of the present invention includes:

[0047] Step S1, adjusting the actual superheat of a plurality of heat exchangers connected in parallel in a multi-split air conditioner according to a target superheat;

[0048] Step S2: determining that each actual superheat reaches the target superheat, then obtaining the outlet temperature of each heat exchanger;

[0049] Step S3: Based on the comparison result of the outlet temperatures of each heat exchanger, the speed of the fan corresponding to each heat exchanger is controlled and adjusted so that the outlet temperatures of all heat exchangers are balanced.

[0050] According to an embodiment of the present invention, the control method for a multi-split air conditioner operates as follows: First, the system adjusts the actual superheat (ΔT) of the multiple heat exchangers connected in parallel within the multi-split air conditioner based on a set target superheat (ΔTset). For example, the refrigerant flow rate can be controlled by adjusting the opening of the electronic expansion valve, so that the difference (superheat ΔT) between the heat exchanger's outlet temperature (Tout) and inlet temperature (Tin) approaches the target value. Subsequently, when the system detects that the actual superheat of each heat exchanger has reached the target superheat, it further obtains the outlet temperature of each heat exchanger. After obtaining these outlet temperatures, the system compares the outlet temperatures of the heat exchangers and adjusts the corresponding fan speed (Ni1 and Ni2) based on the temperature difference. If the outlet temperature difference between two heat exchangers exceeds a certain threshold (e.g., 1°C), the system increases or decreases the corresponding fan speed to reduce the temperature difference and achieve outlet temperature balance.

[0051] In this way, through the above steps, the present invention can balance the outlet temperatures of all heat exchangers in the system, thereby improving the heat exchange efficiency and performance of the entire air-conditioning system.

[0052] In the related technologies, multi-split air conditioners are now widely used due to the fact that the number of internal and external units and output capacity can be freely adjusted according to demand. In the low temperature environment in winter, due to the demand for heat on the indoor side, the outdoor heat exchanger often enters a frosted state. The frost layer will reduce the heat exchange efficiency of the outdoor unit, increase energy consumption and reduce the heating effect of the indoor unit. At present, due to the large size of the multi-split outdoor unit heat exchanger, most of them adopt the method of connecting multiple heat exchanger modules in parallel. It is more common for the heat exchanger to adopt a left-right parallel structure, which is controlled separately by multiple electronic expansion valves to achieve flow control of the whole machine. Due to the differences in the outdoor unit heat exchangers, environmental conditions, and the degree of frost between modules, the control of this multi-heat exchanger structure during the defrosting process is particularly important.

[0053] Currently, refrigerant flow adjustment for multi-module heat exchangers in the same unit is primarily performed through corresponding electronic expansion valves. This is based on the difference between the actual heat exchanger superheat and the set superheat (superheat ΔT = Tout - Tin, where Tout is the heat exchanger outlet temperature in cooling mode and Tin is the heat exchanger inlet temperature in cooling mode). By adjusting the opening of the corresponding electronic expansion valve, the multi-module heat exchanger adjusts the refrigerant flow to each module, thereby maintaining a relatively consistent heat exchanger outlet temperature across the modules and reducing ineffective internal heat exchange after the refrigerants from each module are aggregated.

[0054] Adjusting the electronic expansion valve described above can achieve a certain balance in the heat exchange capacity of each module's heat exchanger. However, in actual operation, especially in heating mode, the frost formation in each module may vary due to factors such as flow diversion and environmental conditions, resulting in more severe frost in one module and less frost in another.

[0055] The heat exchange effect of a multi-module heat exchanger can be adjusted by controlling the refrigerant flow rate through an electronic expansion valve, and by optimizing the speed of each fan to change the temperature distribution of the heat exchanger. Therefore, in order to address the technical defects existing in the above-mentioned related technologies, this patent controls the fans corresponding to each heat exchanger. Specifically, its working principle is as follows:

[0056] After adjusting the superheat, the system needs to monitor the outlet temperature of each heat exchanger in real time to evaluate the heat exchange effect and provide a basis for the next step of fan speed adjustment. That is, after ensuring that the superheat reaches the target value, the temperature distribution of the heat exchanger is further optimized by adjusting the fan speed to reduce the performance degradation caused by frosting.

[0057] If the outlet temperatures of the two heat exchangers differ significantly, it indicates that the heat exchange between them is unbalanced. By increasing or decreasing the fan speed, the air velocity inside the heat exchanger can be changed, thereby adjusting the temperature distribution of the heat exchanger, making the frost layer more evenly distributed, reducing ineffective heat exchange, and improving overall heat exchange efficiency.

[0058] Through the above-mentioned steps of the present invention, a multi-split air conditioner can operate more efficiently in low-temperature environments, reducing energy consumption and improving indoor comfort. This method optimizes air conditioning system performance by precisely controlling the superheat of the heat exchanger and the fan speed. This significantly improves the energy efficiency ratio (EER) and heating performance of the air conditioner, particularly in winter heating mode.

[0059] In summary, the control method of the present invention has at least the following advantages compared to the prior art: (1) Improved energy efficiency: By precisely controlling the outlet temperature of the heat exchanger, the air-conditioning system is ensured to operate in the optimal working state, thereby improving energy utilization efficiency and reducing unnecessary energy waste. (2) Enhanced system stability: The balanced outlet temperature helps to maintain the stable operation of the air-conditioning system, avoids system performance fluctuations caused by temperature fluctuations, and ensures the reliability and durability of the air-conditioning system. (3) Extended equipment life: Reducing additional wear and pressure caused by temperature imbalance helps to reduce equipment maintenance costs and extend the service life of key components such as heat exchangers and fans. (4) Improved user comfort: By achieving a more uniform indoor temperature distribution, the comfort of the living or working environment is improved, especially in multi-split air-conditioning systems, which can ensure that each area can obtain a suitable temperature. (5) Reduced frosting problems: By optimizing the control strategy, the possibility of frosting of the heat exchanger is reduced, which not only improves the heat exchange efficiency, but also reduces the system shutdown and maintenance frequency caused by frosting. (6) Strong adaptability: This method can adapt to different environmental conditions and working conditions, allowing the air conditioning system to maintain efficient operation in various external environments, improving the adaptability and flexibility of the system. (7) Intelligent control: Through real-time monitoring and adjustment, this method demonstrates the advantages of intelligent control, can automatically respond to system changes, and reduces the need for manual intervention.

[0060] For ease of description, the present invention will only describe an example in which a heat exchanger is divided into two symmetrical heat exchange modules. Specifically, a multi-split air conditioner includes a first heat exchanger and a second heat exchanger connected in parallel. The first heat exchanger is correspondingly equipped with a first fan, and the second heat exchanger is correspondingly equipped with a second fan. However, it should be emphasized that the control method of the present invention has the same control effect on multi-split air conditioners with more than two heat exchanger modules. In other words, multi-split air conditioners with more than two heat exchanger modules are also within the scope of protection of the present invention.

[0061] According to some embodiments of the present invention, the step of controlling and adjusting the speed of the fan corresponding to each heat exchanger based on the comparison result between the outlet temperatures of each heat exchanger so as to achieve a balance between the outlet temperatures of all heat exchangers specifically includes:

[0062] Get the current working mode of the multi-split air conditioner;

[0063] In different current working modes, according to the comparison result between the first outlet temperature and the second outlet temperature, the speed of the first fan and / or the second fan is controlled and adjusted until the difference between the first outlet temperature and the second outlet temperature is within the allowable error range.

[0064] The allowable error range is determined according to the current working mode. It is understood that the working mode may include a cooling mode, a heating mode, and the like, and the specific size of the allowable error range is different in the cooling mode and the heating mode.

[0065] In this embodiment, based on the air conditioner's current operating mode, the system dynamically compares the outlet temperatures of two symmetrical heat exchange modules and automatically adjusts the corresponding fan speeds based on the resulting temperature difference. This process ensures that the system maintains stable outlet temperatures even in different operating modes, such as cooling or heating, thereby optimizing energy efficiency, improving user comfort, and enhancing system stability. By setting an acceptable error range, the system can reduce energy consumption while maintaining efficient operation, achieving energy conservation and emission reductions.

[0066] In this way, not only the intelligence level of the air-conditioning system is improved, but also its adaptability and flexibility under different environmental conditions are demonstrated, bringing users a more intelligent, comfortable and environmentally friendly air-conditioning experience.

[0067] Furthermore, the allowable error range includes a cooling error range and a heating error range, and the maximum value of the cooling error range is greater than the maximum value of the heating error range, and the minimum value of the cooling error range is less than the minimum value of the cooling error range.

[0068] In this embodiment, to accommodate the specific needs of different operating modes, the system sets two different allowable error ranges: a cooling error range and a heating error range. In cooling mode, since users are generally more sensitive to temperature, the system sets a smaller cooling error range. This means that when cooling, the system strives to maintain more precise temperature control to ensure indoor comfort. Conversely, in heating mode, since outdoor temperatures are lower and users have a relatively high tolerance for temperature, the heating error range is set more leniently, allowing for certain temperature fluctuations to reduce energy consumption and improve energy efficiency.

[0069] It's understandable that the differentiated error range settings described above reflect the system's dual considerations for user comfort and energy efficiency. In cooling mode, a smaller error range ensures the air conditioner can quickly respond to changes in indoor temperature and provide a more stable supply of cooling air. In heating mode, a larger error range allows the system to optimize operating efficiency by reducing unnecessary energy consumption while maintaining indoor warmth and comfort. This not only improves the intelligence level of the air conditioning system, but also contributes to a more environmentally friendly and energy-efficient operation, while ensuring that users can enjoy a suitable indoor environment in different seasons and operating modes.

[0070] The following first describes the fan speed adjustment process in heating mode.

[0071] According to some embodiments of the present invention, in different current operating modes, the steps of controlling and adjusting the speed of the first fan and / or the second fan according to the comparison result between the first outlet temperature and the second outlet temperature until the difference between the first outlet temperature and the second outlet temperature is within an allowable error range specifically include:

[0072] In the heating mode, if it is determined that the difference between the first outlet temperature and the second outlet temperature is less than the heating error range, and the ratio between the actual speed of the first fan and the standard speed is less than the first speed ratio, the speed of the first fan is controlled to increase the first speed value based on the current actual speed, and the speed of the second fan is maintained unchanged.

[0073] In an embodiment of the present invention, to achieve balanced heat exchanger outlet temperatures in heating mode, the system implements a series of intelligent control measures. First, the system monitors the outlet temperatures of the first and second heat exchangers and calculates the difference between them. If this difference is less than a preset heating error range, and the ratio of the first fan's actual speed to the reference speed (the first speed ratio) is also less than a set value, this indicates that the first heat exchanger's heat transfer efficiency may be insufficient and its operating intensity needs to be increased.

[0074] To address this issue, the system increases the speed of the first fan, based on its current actual speed, to increase air flow through the first heat exchanger, thereby improving its heat exchange efficiency. This is done to narrow the temperature difference between the two heat exchangers, keeping it within an acceptable tolerance. Simultaneously, to maintain system balance, the speed of the second fan remains constant, avoiding unnecessary disruption to the overall system balance.

[0075] According to other embodiments of the present invention, in different current operating modes, the steps of controlling and adjusting the speed of the first fan and / or the second fan according to the comparison result between the first outlet temperature and the second outlet temperature until the difference between the first outlet temperature and the second outlet temperature is within an allowable error range specifically include:

[0076] In the heating mode, if it is determined that the difference between the first outlet temperature and the second outlet temperature is greater than the heating error range, and the ratio between the actual speed of the second fan and the standard speed is less than the first speed ratio, the speed of the second fan is controlled to increase the second speed value based on the current actual speed, and the speed of the first fan is maintained unchanged.

[0077] In another embodiment of the present invention, if the difference between the outlet temperature of the first heat exchanger and the outlet temperature of the second heat exchanger exceeds a preset heating error range, this indicates that the heat exchange effect of the second heat exchanger may need to be enhanced to reduce the temperature difference and improve the overall heating efficiency.

[0078] In this case, the system will take action to increase the speed of the second fan to increase the air flow through the second heat exchanger, thereby improving its heat exchange capacity. The purpose of this is to increase the outlet temperature of the second heat exchanger, thereby narrowing the temperature difference between the outlet and the first heat exchanger and ensuring that the temperature difference remains within an acceptable error range. At the same time, to maintain system balance, the speed of the first fan will remain unchanged to avoid negatively affecting the performance of the first heat exchanger.

[0079] In summary, the intelligent control strategy described above ensures that, in heating mode, the air conditioning system can flexibly adjust to actual needs, achieving efficient heat distribution and temperature control. By precisely adjusting the fan speed, the system not only improves energy efficiency but also ensures indoor temperature uniformity and user comfort, demonstrating the intelligent and automated nature of the air conditioning system.

[0080] The following continues to describe the fan speed adjustment process in cooling mode.

[0081] According to some embodiments of the present invention, in different current operating modes, the steps of controlling and adjusting the speed of the first fan and / or the second fan according to the comparison result between the first outlet temperature and the second outlet temperature until the difference between the first outlet temperature and the second outlet temperature is within an allowable error range specifically include:

[0082] In the cooling mode, if it is determined that the difference between the first outlet temperature and the second outlet temperature is less than the cooling error range, and the ratio between the actual speed of the first fan and the standard speed is less than the second speed ratio, the speed of the second fan is controlled to increase the third speed value based on the current actual speed, and the speed of the first fan is maintained unchanged.

[0083] In the cooling mode of the present invention, when the difference between the outlet temperature of the first heat exchanger and the outlet temperature of the second heat exchanger is already smaller than the cooling error range, and the ratio of the actual speed of the first fan to the standard speed is smaller than the second speed ratio, this means that the cooling effect of the first heat exchanger is sufficient, and the second heat exchanger may require more air flow to improve its cooling efficiency.

[0084] To achieve this, the system increases the second fan's speed by a third value, based on the current actual speed, to enhance the cooling capacity of the second heat exchanger. This adjustment helps further reduce the temperature difference between the two heat exchangers, ensuring a more balanced cooling effect across the entire air conditioning system. At the same time, to maintain stable operation of the first heat exchanger, the first fan's speed remains unchanged.

[0085] According to other embodiments of the present invention, in different current operating modes, the steps of controlling and adjusting the speed of the first fan and / or the second fan according to the comparison result between the first outlet temperature and the second outlet temperature until the difference between the first outlet temperature and the second outlet temperature is within an allowable error range specifically include:

[0086] In the cooling mode, if it is determined that the difference between the first outlet temperature and the second outlet temperature is greater than the cooling error range, and the ratio between the actual speed of the second fan and the standard speed is less than the second speed ratio, the speed of the first fan is controlled to increase to a fourth speed value based on the current actual speed, and the speed of the second fan is maintained unchanged.

[0087] In this embodiment, when the difference between the outlet temperature of the first heat exchanger and the outlet temperature of the second heat exchanger exceeds the cooling error range, this indicates that the system needs to be adjusted to reduce the temperature difference. At the same time, the ratio of the actual speed of the second fan to the standard speed is less than the second speed ratio, which means that the operating speed of the second fan still has room for improvement.

[0088] To address this issue, the system increases the speed of the first fan by a fourth value, based on the current actual speed, to enhance the cooling effect of the first heat exchanger. This increases the air flow through the first heat exchanger, thereby improving its cooling capacity and helping to reduce the temperature difference between the two heat exchangers. At the same time, to maintain system balance and efficiency, the speed of the second fan remains unchanged.

[0089] In summary, the key to the control method of the present invention lies in its ability to dynamically adjust the fan speed based on real-time monitoring data to optimize the cooling performance of the air conditioning system. Through precise control, the system not only improves energy efficiency but also ensures uniformity in indoor temperature, enhancing user comfort. Furthermore, this method helps reduce energy consumption, achieving more environmentally friendly and energy-efficient operation, and embodies the advanced intelligent and automated features of the air conditioning system. Through this intelligent regulation, the air conditioning system can provide an efficient, stable, and comfortable indoor environment in different operating modes, whether cooling or heating.

[0090] According to some embodiments of the present invention, the control method of the multi-split air conditioner further includes:

[0091] Obtaining a first actual current of the first fan and a second actual current of the second fan, and obtaining a target current;

[0092] According to the ratio of at least one of the first actual current and the second actual current to the target current being greater than the set current ratio, the rotational speed of the fan corresponding to the actual current is kept unchanged.

[0093] In addition to adjusting fan speed to balance the heat exchanger outlet temperature, the multi-split air conditioner control method of the present invention also includes a current monitoring and control mechanism. This mechanism involves real-time monitoring of the actual current of the first and second fans and comparing them with target currents. The target current is an ideal value set based on system design and performance requirements, and is used to guide the fan's operating status.

[0094] Specifically, the system obtains the first actual current of the first fan and the second actual current of the second fan, then sets a target current. If the ratio of the actual current to the target current of at least one fan exceeds the set current ratio, this may indicate that the operating status of that fan has approached or exceeded the system's optimal performance point. In this case, to maintain system energy efficiency and stability, the system will choose to maintain the speed of that fan.

[0095] In this way, the steps of this embodiment can ensure that the fan operates at high efficiency, avoiding energy waste or equipment overheating caused by excessive current. In this way, the air conditioning system can achieve optimal energy utilization while ensuring cooling or heating effects, extending the service life of the equipment and reducing maintenance costs.

[0096] According to some embodiments of the present invention, the step of adjusting the actual superheat of a plurality of heat exchangers connected in parallel in a multi-split air conditioner according to a target superheat specifically includes:

[0097] The openings of the electronic expansion valves corresponding to the plurality of heat exchangers are adjusted according to the target superheat.

[0098] Furthermore, the step of adjusting the openings of the electronic expansion valves corresponding to the plurality of heat exchangers according to the target superheat specifically includes:

[0099] In heating mode, the target superheat is determined according to the range of the outdoor ambient temperature, and the opening of the electronic expansion valve is adjusted according to the target superheat;

[0100] Alternatively, in cooling mode, the openings of all electronic expansion valves are controlled to be adjusted to the maximum opening.

[0101] Understandably, in heating mode, the system first determines the target superheat (△Tset) based on the outdoor ambient temperature range. This target value is set based on the outdoor temperature (Tao). For example, when Tao ≥ 10°C, the target superheat is set to 2°C; when 10°C > Tao ≥ 0°C, it is set to 4°C; when 0°C > Tao ≥ -5°C, it is set to 6°C; and when -5°C > Tao, it is set to 8°C.

[0102] The system then adjusts the opening of the electronic expansion valve corresponding to each heat exchanger based on this target superheat. This ensures that the difference (superheat ΔT) between the heat exchanger's outlet temperature (Tout) and inlet temperature (Tin) is close to the target value, thereby optimizing heat exchange efficiency.

[0103] In cooling mode, since the refrigerant outside is in a gaseous state, the system usually adjusts the opening of all electronic expansion valves to the maximum. This is done to ensure that the refrigerant can fully flow through the heat exchanger to achieve efficient cooling effect.

[0104] In summary, the advantage of this control strategy lies in its ability to automatically adjust the heat exchanger's operating state to optimize energy efficiency and performance based on different operating modes and environmental conditions. In heating mode, precise superheat control reduces frost and improves heating efficiency. In cooling mode, a fully open electronic expansion valve ensures efficient operation of the cooling system.

[0105] According to some embodiments of the present invention, the step of determining whether each actual superheat reaches the target superheat specifically includes: determining whether each actual superheat is equal to the target superheat three times in a row.

[0106] In this embodiment, in order to ensure that the actual superheat of the heat exchanger reaches and maintains the target superheat, the system adopts a continuous monitoring and confirmation strategy. The specific steps are as follows: (1) Continuous monitoring of actual superheat: The system will continuously monitor the actual superheat (△T) of each heat exchanger, which is achieved by measuring the difference between the outlet temperature (Tout) and the inlet temperature (Tin) of the heat exchanger. (2) Three consecutive confirmations: In order to verify whether the actual superheat has stably reached the target superheat (△Tset), the system will require that the actual superheat is equal to the target superheat in three consecutive measurements. This continuous confirmation mechanism ensures the stability of the superheat and avoids misjudgment caused by instantaneous fluctuations. (3) Stability confirmation: Once it is confirmed that the actual superheat has reached the target value three times in a row, the system can assume that the operating status of the heat exchanger has stabilized. At this time, the next control strategy can be carried out, such as adjusting the fan speed to further optimize the performance of the heat exchanger.

[0107] In this way, the three consecutive confirmation steps help improve the control accuracy of the air conditioning system and ensure that the heat exchanger operates in the best condition, thereby improving energy efficiency and user comfort.

[0108] A specific embodiment of the control device for a multi-split air conditioner of the present invention is described below.

[0109] The multi-split air conditioning system includes two parallel heat exchanger modules: the first heat exchanger and the second heat exchanger. The first heat exchanger corresponds to the first outlet temperature and the first fan, while the second heat exchanger corresponds to the second outlet temperature and the second fan. The outlet temperatures of the first and second heat exchangers are Tout1 and Tout2, respectively, and the inlet temperatures are Tin1 and Tin2. The actual superheats are △T1 and △T2, and the target superheats are △Tset1 and △Tset2. The default fan speed for the current gear is N0, and the actual speeds for the first and second fans are Ni1 and Ni2, respectively. The default current for the current gear fan supply mode is I0, and the current fan currents for the first and second fans are Ii1 and Ii2, respectively.

[0110] In heating mode, the system first determines the target superheat (△Tset) based on the outdoor ambient temperature range. For example, when Tao ≥ 10°C, the target superheat is set to 2°C; when 10°C > Tao ≥ 0°C, it is set to 4°C; when 0°C > Tao ≥ -5°C, it is set to 6°C; and when -5°C > Tao, it is set to 8°C.

[0111] The system monitors the actual superheat (△T1 and △T2) of the two heat exchangers and adjusts the opening of the electronic expansion valve according to the outdoor ambient temperature to approach the target superheat.

[0112] If the actual superheat is consistent with the target superheat three times in a row, the system will adjust the fan speed according to the outlet temperature difference (Tout1-Tout2):

[0113] If Tout1-Tout2<-1℃ and Ni1 / N0<1.2, the speed of the first fan increases by 5rpm (assumed value); if Tout1-Tout2>1℃ and Ni2 / N0<1.2, the speed of the second fan increases by 5rpm (assumed value); if Tout1-Tout2 is between -1℃ and 1℃, the speeds of the first and second fans remain unchanged.

[0114] Among them, if Ii1 / I0≥1.2, the speed of the first fan is no longer increased; if Ii2 / I0≥1.2, the speed of the second fan is no longer increased.

[0115] It can be understood that in the heating mode, in order to avoid the phenomenon of cyclic fluctuation control of the electronic expansion valve and the fan speed, the present invention makes the superheat and the outlet temperature synchronously tested and calculated, but the superheat of the electronic expansion valve is given priority control, that is, if the opening of the electronic expansion valve needs to be adjusted, the fan speed is adjusted to the default speed of the current gear (if an over-speed increase occurs, the increased part is immediately cleared). In order to avoid frequent adjustments, when the temperature difference between the outlet pipes of the two modules is within 1°C, no adjustment is made. In particular, the fan speed does not increase indefinitely. In the heating mode, due to the increase in wind resistance after frosting, the fan current will increase. When Ii / I0≥1.2 is satisfied, the speed will no longer be increased. Otherwise, the current increase will be risky to the module, and the difference in the fan speeds on both sides is too large, which will cause certain changes in the internal air flow field, which is not conducive to improving the performance of the unit.

[0116] In cooling mode, the openings of all electronic expansion valves are adjusted to their maximum openings to ensure that the refrigerant flows adequately through the heat exchanger.

[0117] The system monitors the outlet temperatures of the two heat exchangers (Tout1 and Tout2) and adjusts the fan speed according to the temperature difference:

[0118] If Tout1-Tout2<-3℃ and Ni1 / N0<1.1, the speed of the first fan increases by 5 rpm (assumed value); if Tout1-Tout2>3℃ and Ni2 / N0<1.1, the speed of the second fan increases by 5 rpm (assumed value); if Tout1-Tout2 is between -3℃ and 3℃, the speeds of both fans remain unchanged.

[0119] Among them, if Ii1 / I0≥1.1, the speed of the first fan is no longer increased; if Ii2 / I0≥1.1, the speed of the second fan is no longer increased.

[0120] It can be understood that in cooling mode, based on the aforementioned control of the electronic expansion valve, the cooling mode decouples the electronic expansion valve opening and adjusts the fan speed solely based on the outlet temperature Tout of the different modules. The outlet temperature is detected and calculated every 30 seconds, and the corresponding fan speed and current are detected simultaneously. Since the outdoor heat exchange module temperature is generally higher in cooling mode, the corresponding temperature detection deviation increases to 3°C. Furthermore, since there is no additional wind resistance in cooling mode, only the current increase caused by the speed increase. Therefore, in cooling mode, Ni1 / N0 is adjusted from 1.2 (for heating) to 1.1. Furthermore, when Ii / I0 ≥ 1.1 is satisfied, the speed increase is no longer applied, as otherwise the increased current would pose a risk to the modules. Furthermore, the significant difference in fan speed between the two sides would cause changes in the internal air flow field, which would be detrimental to improving unit performance.

[0121] The control device of the multi-split air conditioner provided by the present invention is described below. The control device of the multi-split air conditioner described below and the control method of the multi-split air conditioner described above can be referred to each other.

[0122] like Figure 2 As shown, the control device of the multi-split air conditioner according to the second embodiment of the present invention includes:

[0123] The first control module 110 is used to adjust the actual superheat of a plurality of heat exchangers connected in parallel in the multi-split air conditioner according to the target superheat;

[0124] An acquisition module 120 is used to determine that each actual superheat reaches the target superheat, and then obtain the outlet temperature of each heat exchanger;

[0125] The second control module 130 is configured to control and adjust the speed of the fan corresponding to each heat exchanger according to the comparison result between the outlet temperatures of each heat exchanger, so that the outlet temperatures of all heat exchangers are balanced.

[0126] According to the third embodiment of the present invention, the multi-split air conditioner includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the control method of the multi-split air conditioner according to the first embodiment of the present invention is implemented.

[0127] Figure 3 An example of a physical structure diagram of an electronic device is shown below. Figure 3 As shown, the electronic device may include: a processor 810, a communications interface 820, a memory 830, and a communications bus 840, wherein the processor 810, the communications interface 820, and the memory 830 communicate with each other via the communications bus 840. The processor 810 may call logic instructions in the memory 830 to execute a control method for a multi-split air conditioner, including: adjusting the actual superheat of a plurality of heat exchangers connected in parallel within the multi-split air conditioner according to a target superheat; determining that each actual superheat reaches the target superheat, obtaining the outlet temperature of each heat exchanger; and controlling and adjusting the speed of the fan corresponding to each heat exchanger based on a comparison result between the outlet temperatures of each heat exchanger to achieve a balance between the outlet temperatures of all heat exchangers.

[0128] In addition, the logic instructions in the above-mentioned memory 830 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when sold or used as an independent product. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the various embodiments of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0129] On the other hand, the present invention also provides a computer program product, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the control method of the multi-split air conditioner provided by the above methods, including: adjusting the actual superheat of several heat exchangers connected in parallel in the multi-split air conditioner according to the target superheat; determining that each actual superheat reaches the target superheat, then obtaining the outlet temperature of each heat exchanger; and controlling and adjusting the speed of the fan corresponding to each heat exchanger according to the comparison result between the outlet temperatures of each heat exchanger so that the outlet temperatures of all heat exchangers are balanced.

[0130] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, it is implemented to execute the control method of the multi-split air conditioner provided by the above-mentioned methods, including: adjusting the actual superheat of several heat exchangers connected in parallel in the multi-split air conditioner according to the target superheat; determining that each actual superheat reaches the target superheat, then obtaining the outlet temperature of each heat exchanger; and controlling and adjusting the speed of the fan corresponding to each heat exchanger according to the comparison result between the outlet temperatures of each heat exchanger so that the outlet temperatures of all heat exchangers are balanced.

[0131] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units. That is, they may be located in one place or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0132] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus the necessary general hardware platform, or of course, by hardware. Based on this understanding, the essence of the above technical solution or the part that contributes to the existing technology can be embodied in the form of a software product. The computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods of each embodiment or certain parts of the embodiment.

[0133] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A control method for a multi-split air conditioner, characterized in that: include: Adjusting the actual superheat of a plurality of heat exchangers connected in parallel in the multi-split air conditioner according to the target superheat; Determining that each of the actual superheats reaches the target superheat, then obtaining the outlet temperature of each of the heat exchangers; According to the comparison result between the outlet temperatures of each heat exchanger, the rotation speed of the fan corresponding to each heat exchanger is controlled and adjusted so that the outlet temperatures of all the heat exchangers reach a balance.

2. The control method of a multi-split air conditioner according to claim 1, characterized in that: The multi-split air conditioner includes a first heat exchanger and a second heat exchanger connected in parallel, the first heat exchanger is correspondingly installed with a first fan, and the second heat exchanger is correspondingly installed with a second fan; The step of controlling and adjusting the speed of the fan corresponding to each heat exchanger according to the comparison result between the outlet temperatures of each heat exchanger so that the outlet temperatures of all the heat exchangers reach a balance specifically includes: Obtaining the current operating mode of the multi-split air conditioner; Under different current operating modes, according to a comparison result between the first outlet temperature and the second outlet temperature, controlling and adjusting the speed of the first fan and / or the second fan until the difference between the first outlet temperature and the second outlet temperature is within an allowable error range; The allowable error range is determined according to the current working mode.

3. The control method of a multi-split air conditioner according to claim 2, characterized in that: The allowable error range includes a cooling error range and a heating error range, and a maximum value of the cooling error range is greater than a maximum value of the heating error range, and a minimum value of the cooling error range is less than a minimum value of the cooling error range.

4. The control method of a multi-split air conditioner according to claim 3, characterized in that: The step of controlling and adjusting the rotational speed of the first fan and / or the second fan according to the comparison result between the first outlet temperature and the second outlet temperature in different current operating modes until the difference between the first outlet temperature and the second outlet temperature is within an allowable error range specifically includes: In the heating mode, if it is determined that the difference between the first outlet temperature and the second outlet temperature is less than the heating error range, and the ratio between the actual speed of the first fan and the standard speed is less than the first speed ratio, the speed of the first fan is controlled to increase the first speed value based on the current actual speed, and the speed of the second fan is maintained unchanged.

5. The control method of a multi-split air conditioner according to claim 3, characterized in that: The step of controlling and adjusting the rotational speed of the first fan and / or the second fan according to the comparison result between the first outlet temperature and the second outlet temperature in different current operating modes until the difference between the first outlet temperature and the second outlet temperature is within an allowable error range specifically includes: In the heating mode, if it is determined that the difference between the first outlet temperature and the second outlet temperature is greater than the heating error range, and the ratio between the actual speed of the second fan and the standard speed is less than the first speed ratio, the speed of the second fan is controlled to increase the second speed value based on the current actual speed, and the speed of the first fan is maintained unchanged.

6. The control method of a multi-split air conditioner according to claim 3, characterized in that: The step of controlling and adjusting the rotational speed of the first fan and / or the second fan according to the comparison result between the first outlet temperature and the second outlet temperature in different current operating modes until the difference between the first outlet temperature and the second outlet temperature is within an allowable error range specifically includes: In the cooling mode, if it is determined that the difference between the first outlet temperature and the second outlet temperature is less than the cooling error range, and the ratio between the actual speed of the first fan and the standard speed is less than the second speed ratio, the speed of the second fan is controlled to increase to a third speed value based on the current actual speed, and the speed of the first fan is maintained unchanged.

7. The control method of a multi-split air conditioner according to claim 3, characterized in that: The step of controlling and adjusting the rotational speed of the first fan and / or the second fan according to the comparison result between the first outlet temperature and the second outlet temperature in different current operating modes until the difference between the first outlet temperature and the second outlet temperature is within an allowable error range specifically includes: In the cooling mode, if it is determined that the difference between the first outlet temperature and the second outlet temperature is greater than the cooling error range, and the ratio between the actual speed and the standard speed of the second fan is less than the second speed ratio, the speed of the first fan is controlled to increase to a fourth speed value based on the current actual speed, and the speed of the second fan is maintained unchanged.

8. The control method of a multi-split air conditioner according to any one of claims 3 to 7, characterized in that: Also includes: Obtaining a first actual current of the first fan and a second actual current of the second fan, and obtaining a target current; According to the ratio of at least one of the first actual current and the second actual current to the target current being greater than the set current ratio, the speed of the fan corresponding to the actual current is kept unchanged.

9. The control method of a multi-split air conditioner according to any one of claims 1 to 7, characterized in that: The step of adjusting the actual superheat of the plurality of heat exchangers connected in parallel in the multi-split air conditioner according to the target superheat specifically includes: The openings of the electronic expansion valves respectively corresponding to the plurality of heat exchangers are adjusted according to the target superheat.

10. The control method of a multi-split air conditioner according to claim 9, characterized in that: The step of adjusting the openings of the electronic expansion valves corresponding to the plurality of heat exchangers according to the target superheat specifically includes: In heating mode, the target superheat is determined according to the range of the outdoor ambient temperature, and the opening of the electronic expansion valve is adjusted according to the target superheat; Alternatively, in the cooling mode, the openings of all the electronic expansion valves are controlled to be adjusted to the maximum opening.

11. The control method of a multi-split air conditioner according to any one of claims 1 to 7, characterized in that: The step of determining whether each of the actual superheat degrees reaches the target superheat degree specifically includes: determining whether each of the actual superheat degrees is equal to the target superheat degree for three consecutive times.

12. A control device for a multi-split air conditioner, characterized in that: include: a first control module, configured to adjust actual superheats of a plurality of heat exchangers connected in parallel within the multi-split air conditioner according to a target superheat; an acquisition module, configured to determine that each of the actual superheat degrees reaches the target superheat degree, and then acquire the outlet temperature of each of the heat exchangers; The second control module is used to control and adjust the rotation speed of the fan corresponding to each heat exchanger according to the comparison result between the outlet temperatures of each heat exchanger, so that the outlet temperatures of all the heat exchangers are balanced.

13. A multi-split air conditioner, characterized in that: The method comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the method for controlling a multi-split air conditioner according to any one of claims 1 to 11 is implemented.

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