Control method for air conditioning system

Abstract

Disclosed in the present application is a control method for an air conditioning system. The method comprises: on the basis of historical learning data of an indoor unit and a load feature learning model, learning a refrigeration load parameter of a room corresponding to the indoor unit, wherein the refrigeration load parameter is obtained by means of self-learning; on the basis of a desired indoor temperature at the current moment, the refrigeration load parameter, an indoor temperature, an outdoor temperature and a control period, determining a required load at the current moment; and on the basis of the required load, controlling operating parameters of an air conditioning system.

Description

Air conditioning system control methods

[0001] This application claims priority to Chinese patent application No. 202411074126.3, filed on August 6, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of air conditioning technology, and in particular to a control method for an air conditioning system. Background Technology

[0003] Currently, the control target of air conditioning systems is typically the difference between the set temperature and the return air temperature. This temperature difference serves as a key reference for the compressor frequency, evaporation temperature, and superheat in the control system. However, since this temperature difference only reflects the temperature state of the target room, it is only one important parameter in the air heat load component of the building load. Furthermore, heat leakage load, solar radiation load, and internal disturbance load are also important components of the building load. Therefore, simply using the temperature difference as the control target can easily lead to problems such as under-adjustment under small temperature differences with large loads, over-adjustment under large temperature differences with small loads, and room temperature fluctuations under medium loads. This also results in frequent unit start-ups and shutdowns, low energy efficiency, and poor user experience.

[0004] The information disclosed in this background section is only intended to enhance the understanding of the background technology of this application, and therefore may include prior art that is not known to those skilled in the art. Summary of the Invention

[0005] This application provides a control method for an air conditioning system, including:

[0006] The cooling load parameters of the room corresponding to the indoor unit are determined based on historical learning data and load characteristic learning models; the historical learning data includes the indoor temperature, set temperature, outdoor temperature and indoor unit capacity at several historical moments.

[0007] Get the current indoor temperature and the current outdoor temperature;

[0008] Determine the desired indoor temperature at the current moment;

[0009] The demand load at the current moment is determined based on the cooling load parameters, the current indoor temperature, the current desired indoor temperature, the current outdoor temperature, and the control cycle.

[0010] The operating parameters of the air conditioning system are determined based on the demand load at the current moment.

[0011] According to the control method of the air conditioning system in this application, the air conditioner learns the cooling load parameters of the corresponding room based on the historical learning data and load characteristic learning model of the indoor unit. It then determines the current demand load based on the desired indoor temperature, cooling load parameters, indoor temperature, outdoor temperature, and control cycle. The operating parameters of the air conditioning system are controlled according to the demand load. The cooling load parameters obtained through self-learning more accurately reflect the current load state of the room, and the determined current demand load can be matched with the real-time load of the corresponding room. Therefore, by controlling the operating parameters of the air conditioning system based on the real-time demand load of the room, the operating state of the air conditioning system can match the real-time demand load of the room, achieving load following and control, avoiding under-adjustment, over-adjustment, and room temperature fluctuations. Under low to medium loads, it can reduce room temperature fluctuations and avoid frequent start-stop cycles that increase power consumption, improving system reliability and achieving energy saving and efficiency. Under high loads, it can enhance the capacity of the indoor unit, accelerate the rate of room temperature change, and improve user comfort.

[0012] In some embodiments, the load feature learning model is represented by the following formula: Q e =a×(T) i -T s )+b×(T a -T i )×t1+c×t1

[0013] Among them, Q e The indoor unit's capacity is represented by a, b, and c; these are the cooling load parameters; T i Indoor temperature; T s To set the temperature; T a t1 represents the outdoor temperature; t1 represents the learning step size.

[0014] The determination of the current demand load based on cooling load parameters, current indoor temperature, current desired indoor temperature, current outdoor temperature, and control cycle includes determining the current demand load based on the following formula: Q r(n) =a×(T) i(n) -T exp(n) )+b×(T a(n) -T i(n) )×t2+c×t2

[0015] Among them, Q r(n) T represents the current demand load; i(n) The current indoor temperature; T exp(n) The desired indoor temperature; T a(n) The outdoor temperature at the current moment; T i(n) t1 represents the indoor temperature; t2 represents the control cycle.

[0016] Determining the demand load based on cooling load parameters, the difference between indoor temperature and desired indoor temperature, and the difference between outdoor temperature and indoor temperature can improve the accuracy of demand load determination at the current moment.

[0017] In some embodiments, determining the desired indoor temperature at the current moment includes:

[0018] Obtain the temperature characteristic constant, the initial indoor temperature, the previous indoor temperature, and the set temperature;

[0019] The desired indoor temperature at the current moment is determined based on the initial indoor temperature, the difference between the previous indoor temperature and the set temperature, the difference between the initial indoor temperature and the set temperature, the time from the initial moment to the current moment, and the temperature characteristic constant.

[0020] The desired indoor temperature determined by the above method can quickly and accurately bring the room temperature to the set temperature. In the early stage of cooling, the room temperature will be rapidly reduced based on the difference between the current time and the set temperature and the expected total cooling time. In the later stage of cooling, the speed will slow down, and the room temperature will be precisely adjusted to the set temperature value.

[0021] In some embodiments, the operating parameters include the compressor frequency at the current moment, and determining the compressor frequency at the current moment based on the current demand load includes:

[0022] Obtain the current actual evaporation temperature of the indoor unit;

[0023] The target evaporation temperature of the indoor unit at the current moment is determined based on the current demand load and the current indoor temperature.

[0024] Obtain the compressor frequency, the actual evaporation temperature of the indoor unit, and the target evaporation temperature of the previous moment;

[0025] The compressor frequency at the current moment is determined based on the difference between the actual evaporation temperature of the indoor unit at the previous moment and the target evaporation temperature at the previous moment, the difference between the actual evaporation temperature of the indoor unit at the current moment and the target evaporation temperature at the current moment, and the compressor frequency at the previous moment.

[0026] The air conditioning system determines the current demand load, determines the target evaporation temperature based on the current demand load, and determines the current compressor frequency based on the difference between the current actual evaporation temperature and the target evaporation temperature, the difference between the previous actual evaporation temperature and the target evaporation temperature, and the compressor frequency of the previous moment. Therefore, the air conditioning system determines the current compressor operating frequency based on the change in demand load and the compressor frequency of the previous moment to achieve load following control, so that the operating capacity of the air conditioning system matches the demand load, thereby achieving smooth adjustment of the compressor frequency.

[0027] In some embodiments, determining the compressor frequency at the current moment based on the difference between the actual evaporation temperature of the indoor unit at the previous moment and the target evaporation temperature at the previous moment, the difference between the actual evaporation temperature of the indoor unit at the current moment and the target evaporation temperature at the current moment, and the compressor frequency at the previous moment includes:

[0028] Obtain the compressor characteristic parameter S, and the compressor iterative correction coefficients m1 and m2;

[0029] The compressor frequency at the current moment is calculated based on the following formula:

[0030] Among them, H (n) The compressor frequency at the current moment;

[0031] H (n-1) The compressor frequency at the previous moment;

[0032] ΔT ep(n) This represents the difference between the current actual evaporation temperature of the indoor unit and the target evaporation temperature.

[0033] ΔT ep(n-1) This is the difference between the actual evaporation temperature of the indoor unit and the target evaporation temperature at the previous moment.

[0034] The compressor frequency is corrected by using compressor characteristic parameters S, compressor iteration correction coefficient m, and compressor iteration correction coefficient n to improve the accuracy of compressor frequency determination.

[0035] In some embodiments, determining the target evaporation temperature of the indoor unit at the current moment based on the current demand load and the current indoor temperature includes: obtaining the model characteristic parameters of the indoor unit, and determining the target evaporation temperature of the indoor unit at the current moment based on the current indoor temperature, the current demand load, the model characteristic parameters of the indoor unit, and the control cycle.

[0036] The target evaporation temperature is determined by the current demand load, which is then used to further control the compressor frequency.

[0037] In some embodiments, when the air conditioning system includes multiple indoor units that are turned on, the minimum value of the target evaporation temperature of the multiple indoor units at the current moment is determined as the target evaporation temperature at the current moment; and the average value of the actual evaporation temperature of the multiple indoor units at the current moment is taken as the actual evaporation temperature.

[0038] The minimum target evaporation temperature of all operating indoor units is used as the target evaporation temperature to ensure that the determined compressor frequency can meet the demand load. The average of the current actual evaporation temperatures of multiple indoor units is used as the actual evaporation temperature to more accurately reflect the actual evaporation temperature of the system.

[0039] In some embodiments, the operating parameters include the compressor frequency at an initial time, and determining the compressor frequency at the initial time based on the demand load at the initial time includes:

[0040] Obtain compressor characteristic parameters;

[0041] Determine the initial demand load;

[0042] The compressor frequency at the initial moment is determined based on the compressor characteristic parameters, the demand load at the initial moment, and the control cycle.

[0043] The compressor frequency at the initial moment is determined based on the demand load at the initial moment, so that the compressor frequency at the initial moment meets the demand load requirements at the initial moment, thereby achieving rapid cooling in the initial stage of refrigeration.

[0044] In some embodiments, the operating parameters include the indoor unit fan speed, and determining the indoor unit fan speed based on the current demand load includes:

[0045] The capacity characteristic coefficient of the indoor unit and the demand load at the current moment are obtained. The compressor frequency correction coefficient is determined based on the demand load at the current moment, the capacity characteristic coefficient of the indoor unit, and the control cycle. The indoor unit fan baffle is determined based on the compressor frequency correction coefficient. The indoor fan baffle is positively correlated with the compressor frequency correction coefficient.

[0046] The indoor fan speed is adjusted according to the current demand load to further ensure that the indoor unit can meet the demand load.

[0047] In some embodiments, the air conditioning system includes an indoor expansion valve, and the method for controlling the opening degree of the indoor expansion valve includes:

[0048] The real-time superheat value of the indoor unit is determined. When the real-time superheat value is below the set value, the opening of the indoor expansion valve remains unchanged. When the real-time superheat value is above the set value, the opening of the indoor expansion valve is increased.

[0049] By adjusting the opening of the indoor expansion valve, the real-time superheat is kept below the set value to ensure the normal operation of the compressor and the evaporation capacity of the indoor unit.

[0050] In some embodiments, the initial opening of the indoor expansion valve is determined based on the maximum opening of the indoor expansion valve and the ratio of the capacity of the currently operating indoor unit to the sum of the capacities of all operating indoor units.

[0051] The initial opening of the indoor expansion valve determined by the above method makes the refrigerant distribution more reasonable.

[0052] In some embodiments, the method for determining the increase in the opening degree of the indoor expansion valve includes:

[0053] Obtain the overheating iterative correction coefficient;

[0054] The first difference is calculated as the difference in superheat between the current moment and the previous moment.

[0055] The difference in superheat between the previous moment and the moment before that is calculated as the second difference.

[0056] The increase in the opening of the indoor expansion valve is determined based on the first difference, the difference between the first difference and the second difference, and the superheat iterative correction coefficient.

[0057] The method for determining the increase in the opening of the indoor expansion valve can ensure that the opening of the indoor expansion valve is adjusted smoothly and continuously.

[0058] Other features and advantages of this application will become clearer after reading the detailed embodiments in conjunction with the accompanying drawings. Attached Figure Description

[0059] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0060] Figure 1 is a flowchart of the control method of the air conditioning system according to an embodiment.

[0061] Figure 2 is a schematic diagram of refrigerant circulation in the cooling mode of the air conditioning system according to an embodiment.

[0062] Figure 3 is a flowchart of determining the cooling load parameters of the air conditioning system according to an embodiment.

[0063] Figure 4 is a flowchart of the indoor unit's historical operating data that can be used for model learning when the air conditioning system is in cooling mode according to the embodiment.

[0064] Figure 5 is a flowchart of determining the real-time demand load in the cooling mode of the air conditioning system according to an embodiment.

[0065] Figure 6 is a flowchart of determining the compressor frequency at the initial moment of the air conditioning system's cooling mode according to an embodiment.

[0066] Figure 7 is a flowchart of real-time compressor frequency control in the cooling mode of the air conditioning system according to an embodiment.

[0067] Figure 8 is a flowchart of determining the initial fan speed at the initial moment of the air conditioning system's cooling mode according to an embodiment.

[0068] Figure 9 is a control flowchart of the air conditioning system cooling mode fan speed according to an embodiment.

[0069] Figure 10 is a control flowchart of the indoor expansion valve in the cooling mode of the air conditioning system according to an embodiment. Detailed Implementation

[0070] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0071] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0072] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0073] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0074] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0075] The following disclosure provides many different embodiments or examples for implementing different structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in this application, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0076] The air conditioning system disclosed in this application executes a refrigeration cycle using a compressor, condenser, throttling device, and evaporator. The refrigeration cycle includes a series of processes involving compression, condensation, expansion, and evaporation to cool or heat an indoor space.

[0077] Low-temperature, low-pressure refrigerant enters the compressor, which compresses it into a high-temperature, high-pressure refrigerant gas and discharges it. The discharged refrigerant gas flows into the condenser. The condenser condenses the compressed refrigerant into a liquid phase, and heat is released to the surrounding environment through the condensation process. A throttling device causes the high-temperature, high-pressure liquid refrigerant formed in the condenser to expand into a low-pressure liquid refrigerant. The evaporator evaporates the refrigerant that expanded in the throttling device and returns the low-temperature, low-pressure refrigerant gas to the compressor. The evaporator achieves a cooling effect by utilizing the latent heat of refrigerant evaporation to exchange heat with the material being cooled. Throughout the cycle, the air conditioner regulates the temperature of the indoor space.

[0078] The outdoor unit of an air conditioning system includes a compressor, an outdoor heat exchanger, and a throttling device.

[0079] The indoor unit of the air conditioning system includes an indoor heat exchanger. The air conditioning system includes at least one indoor unit, and each indoor unit is equipped with an indoor expansion valve. The capacity of the indoor unit is adjusted by adjusting the opening degree of the indoor expansion valve.

[0080] In some embodiments, the air conditioning system includes an outdoor unit and an indoor unit, the outdoor unit including a compressor and an outdoor heat exchanger, and the indoor unit including an indoor heat exchanger and an indoor expansion valve.

[0081] In some embodiments, the air conditioning system includes an outdoor unit and multiple indoor units; in this case, the air conditioning system is also referred to as a multi-split system. The outdoor unit includes a compressor and an outdoor heat exchanger, and each indoor unit includes an indoor heat exchanger and an indoor expansion valve. The indoor and outdoor heat exchangers function as either condensers or evaporators. When the indoor heat exchanger functions as a condenser, the air conditioner functions as a heater in heating mode; when the indoor heat exchanger functions as an evaporator, the air conditioner functions as a cooler in cooling mode.

[0082] This application provides a control method for an air conditioning system, including:

[0083] The cooling load parameters of the corresponding room for the indoor unit are determined based on historical learning data and load characteristic learning models.

[0084] Get the current indoor temperature and the current outdoor temperature;

[0085] Determine the desired indoor temperature at the current moment, and determine the demand load at the current moment based on the cooling load parameters, the current indoor temperature, the desired temperature at the current moment, the current outdoor temperature, and the control cycle.

[0086] The operating parameters of the air conditioning system are determined based on the current demand load.

[0087] In some embodiments, historical learning data includes indoor temperature, set temperature, outdoor temperature, and indoor unit capabilities at several historical moments.

[0088] The cooling load parameters of the air conditioning system are obtained through self-learning. These parameters more accurately reflect the current load status of the room, and the determined current demand load matches the real-time load of the corresponding room for each indoor unit. Therefore, by controlling the operating parameters of the air conditioning system based on the real-time demand load of the room, the system's operating state is matched to the room's real-time demand load, avoiding under-adjustment, over-adjustment, and room temperature fluctuations. Under low to medium loads, this reduces room temperature fluctuations and avoids increased power consumption due to frequent start-stop cycles, improving system reliability and achieving energy savings. Under high loads, it enhances the capacity of the indoor units, accelerates room temperature changes, and improves user comfort.

[0089] In the embodiment shown in Figure 1, the control method for the air conditioning system includes:

[0090] S1, Begin.

[0091] S2. Determine the cooling load parameters of the room corresponding to the indoor unit based on historical learning data and load characteristic learning model.

[0092] S3. Obtain the current indoor and outdoor temperatures.

[0093] S4. Determine the desired indoor temperature at the current moment. Based on the cooling load parameters, the current indoor temperature, the desired indoor temperature at the current moment, the current outdoor temperature, and the control cycle, determine the demand load at the current moment.

[0094] S5. Determine the operating parameters of the air conditioning system based on the current demand load. The following explanation uses a multi-split air conditioning system as an example. Figure 2 is a schematic diagram of the refrigerant circulation in the cooling mode of a multi-split system. In the example in Figure 2, the air conditioning system includes an outdoor unit and three indoor units: a first indoor unit, a second indoor unit, and a third indoor unit. The outdoor unit is connected to the first, second, and third indoor units via connecting pipes to form the air conditioning system.

[0095] The outdoor unit is equipped with a compressor 1, an outdoor heat exchanger 5, an outdoor expansion valve 6, and a four-way valve 4. The operating capacity of the outdoor unit can be adjusted by regulating the operating frequency of the compressor 1.

[0096] The outdoor unit is also equipped with an outdoor temperature acquisition module to obtain the outdoor temperature T. a .

[0097] In some embodiments, the outdoor temperature acquisition module acquires the outdoor ambient temperature through hardware, for example, the outdoor ambient temperature acquisition module is a temperature sensor installed in the outdoor unit.

[0098] In some embodiments, the outdoor temperature acquisition module acquires the outdoor temperature via software, for example, the outdoor ambient temperature acquisition module acquires the outdoor temperature via a network.

[0099] The first indoor unit is equipped with a first indoor heat exchanger 18-1, a first indoor expansion valve 19-1 and a first indoor fan (not shown in the figure). The operating capacity of the first indoor unit can be adjusted by adjusting the opening of the first indoor expansion valve 19-1 and / or the speed of the first indoor fan.

[0100] The first indoor unit includes a first indoor ambient temperature detection module d1, a first indoor unit liquid pipe temperature detection module c1, and a first indoor unit gas pipe temperature detection module b1.

[0101] The second indoor unit is equipped with a second indoor heat exchanger 18-2, a second indoor expansion valve 19-2, and a second indoor fan. The operating capacity of the second indoor unit can be adjusted by adjusting the opening of the second indoor expansion valve 19-2 and / or the speed of the second indoor fan.

[0102] The second indoor unit includes a second indoor ambient temperature detection module d2, a second indoor unit liquid pipe temperature detection module c2, and a second indoor unit gas pipe temperature detection module b2.

[0103] The third indoor unit is equipped with a third indoor heat exchanger 18-3, a third indoor expansion valve 19-3, and a third indoor fan (not shown in the figure). The operating capacity of the third indoor unit can be adjusted by adjusting the opening of the third indoor expansion valve 19-3 and / or the speed of the third indoor fan.

[0104] The third indoor unit includes a third indoor ambient temperature detection module d3, a third indoor unit liquid pipe temperature detection module c3, and a third indoor unit gas pipe temperature detection module b3.

[0105] The indoor ambient temperature detection module is used to detect the indoor temperature T. i .

[0106] All indoor units include a set temperature acquisition module, which is used to acquire the indoor set temperature T. s .

[0107] A load characteristic model is established based on the actual composition of the building load, and the indoor unit capacity Q is obtained. e The load characteristics of the building are learned by treating the actual building load Q, and a load characteristic model is established.

[0108] The building load characteristic model can represent indoor air heat storage load, wall and window heat leakage load, or equipment and personnel internal disturbance load. Among these, the air heat storage load is related to room size and the difference between the set temperature and the initial temperature. The wall and window heat leakage load is mainly related to building insulation and the indoor-outdoor temperature difference. The equipment and personnel internal disturbance load is related to the usage scenario.

[0109] The model learning requires selecting a complete cooling process, using the operational data of this process as historical learning data to determine the cooling load parameters in the load characteristic learning model, and finally forming a load characteristic model for the target building.

[0110] In some embodiments, the load feature learning model is represented by the following formula: Q e =Q=a×(T) i -T s )+b×(T a -T i )×t1+c×t1

[0111] Where a, b, and c are cooling load parameters, T i Indoor temperature, T s To set the temperature, T a t1 represents the outdoor temperature and t1 represents the learning step size.

[0112] The learning step size t1 is a predetermined time interval for learning data, which can be adjusted according to needs.

[0113] Select at least 3 moments from the historical learning data with a learning step size t1, and store the corresponding indoor unit historical learning data (Q) for those moments. e(n) T i(n) T a(n)， (n represents the time) is substituted into the load characteristic learning model to establish equations to solve for the building load characteristic parameters a, b, and c.

[0114] Indoor unit capacity Q e It is a function related to the indoor unit heat exchanger's structural parameters, heat transfer characteristic parameters, superheat, subcooling, and evaporation temperature, which can be calculated using existing technology: Q e =f(S) str ,K,SH,SC,T e )

[0115] In the above formula:

[0116] S str Indoor heat exchanger structural parameters;

[0117] K: Heat exchange characteristic parameters of the indoor heat exchanger under current operating conditions;

[0118] SH: Superheat at the outlet of the indoor heat exchanger, in °C;

[0119] SC: Inlet subcooling of the indoor heat exchanger, in °C;

[0120] T e : Evaporation temperature of indoor heat exchanger, °C.

[0121] After the load characteristic model is established, the current outdoor ambient temperature, indoor temperature, and desired indoor temperature can be input into the model to determine the current room demand load. The system operating parameters can then be adjusted based on the demand load and control objectives.

[0122] In a multi-split air conditioning system, it is necessary to determine the cooling load parameters of the room corresponding to each indoor unit. Therefore, for the j-th indoor unit, the building load characteristic learning model is as follows: Q ej =Q j =a j ×(T ij -T sj )+b j ×(T a -T ij )×t1+c j ×t1

[0123] In the above formula:

[0124] Q ej The capacity of the j-th indoor unit, in kW;

[0125] Q j : The building load corresponding to the j-th indoor unit, in kW;

[0126] a j b j c j : Cooling load parameters corresponding to the j-th indoor unit, dimensionless unit;

[0127] T ij : The indoor temperature corresponding to the j-th indoor unit, in °C;

[0128] T sj : The set temperature corresponding to the j-th indoor unit, in °C;

[0129] T a Outdoor temperature, °C;

[0130] t1: Learning time step, min.

[0131] The capacity of the j-th indoor unit Q ej It is a function related to the indoor unit heat exchanger's structural parameters, heat transfer characteristic parameters, superheat, subcooling, and evaporation temperature, which can be calculated using existing technology: Q ej =f(S)strj ,K j ,SH j ,SC j ,T ej )

[0132] In the above formula:

[0133] S strj : Structural parameters of the j-th indoor heat exchanger;

[0134] K j : Heat exchange characteristic parameters of the j-th indoor heat exchanger under current operating conditions;

[0135] SH j : Superheat at the outlet of the j-th indoor heat exchanger, °C;

[0136] SC j : Subcooling degree at the inlet of the j-th indoor heat exchanger, °C;

[0137] T ej Evaporation temperature of the jth indoor heat exchanger, °C.

[0138] In some embodiments, to avoid the inability to self-learn and determine the cooling load parameters upon initial startup, the system checks whether it is the first time it has been started. If it is, the built-in cooling load parameters a0, b0, and c0 of the multi-split unit are read and used to control the system. If it is not the first time, it is necessary to determine whether self-learning is required for this operation. If the self-learning conditions are met, self-learning is performed to determine the cooling load parameters, and the learned cooling load parameters are used to control the system. During subsequent startups, it is checked whether self-learning is required. If not, the cooling load parameters determined by the previous self-learning are used for control; if so, self-learning is performed to determine the cooling load parameters, and the learned cooling load parameters are used to control the system.

[0139] In the example in Figure 3, the process for determining the cooling load parameters using the cooling mode is as follows:

[0140] S31, Begin.

[0141] S32. Determine if this is the first time the device is powered on. If yes, proceed to step S33; otherwise, proceed to step S34.

[0142] S33. Read the built-in cooling load parameters a0, b0, and c0 of the multi-split unit as cooling load parameters.

[0143] S34. Determine whether the cooling self-learning conditions are met. If not, proceed to step S35. If yes, proceed to step S36.

[0144] S35. Obtain the cooling load parameters from the previous run.

[0145] S36. Perform self-learning to determine the cooling load parameters after learning.

[0146] In some embodiments, the cooling load parameters are self-learned under the following two conditions:

[0147] Condition 1: The indoor unit has not undergone any learning process since it was turned on this time;

[0148] Condition 2: The time elapsed since the last learning session ended is greater than the set time.

[0149] In some embodiments, the following three conditions must be met before self-learning of cooling load parameters is performed:

[0150] Condition 1: The indoor unit has not undergone any learning process since it was turned on this time;

[0151] Condition 2: The duration since the last learning session ended is greater than the set time;

[0152] Condition 3: Ability to obtain historical learning data of indoor units that can be used for model learning.

[0153] The air conditioning cooling process includes several cooling stages. Historical data of complete cooling stages that meet the following criteria are used as historical learning data: the total cooling time is greater than the set time Ymin; the absolute value of the initial indoor temperature difference between the indoor and outdoor temperatures during the cooling process is lower than the set temperature difference; the change in indoor temperature within a specific time period is higher than the first set difference; and the final indoor temperature difference between the cooling process and the set temperature is lower than the second set difference. Historical data of the cooling process are used as historical learning data.

[0154] The temperature change trend during the complete cooling process is downward.

[0155] From the aforementioned historical learning data, at least three time points are selected with a learning step size t1, and the corresponding indoor unit historical learning data (Q) is used to record these time points. e(n) T i(n) T a(n)， (n represents the time) is substituted into the load characteristic learning model to establish equations to solve for the building load characteristic parameters a, b, and c.

[0156] In the example in Figure 4, the method for obtaining historical learning data that can be used for model learning includes the following steps:

[0157] S41, Begin.

[0158] S42. Select the indoor mechanism's cold running period for the purpose of learning, and obtain the operating parameters for that period: running length t n Indoor temperature T iOutdoor temperature T a and set temperature T s .

[0159] S43. Determine whether the runtime tn is greater than or equal to the set runtime Y. min If yes, proceed to step S44; otherwise, proceed to step S42.

[0160] S44. Determine the initial indoor temperature T i(0) With outdoor temperature T a(0) If the absolute value of the temperature difference is lower than or equal to the set temperature difference k, proceed to step S45; otherwise, proceed to step S42.

[0161] S45. Determine whether the change in indoor temperature within a specific time period is higher than a first preset difference. If yes, proceed to step S46; otherwise, proceed to step S42.

[0162] The first set difference is, for example, 0.5℃.

[0163] S46. Determine whether the final indoor temperature is the same as the set temperature. If yes, proceed to step S47; otherwise, proceed to step S42.

[0164] S47, based on the indoor temperature T during this operating period. i Outdoor temperature T a Set temperature T s Learning time step t1 and corresponding indoor unit capability Q e As historical learning data.

[0165] In some embodiments, determining the desired indoor temperature at the current moment includes:

[0166] Obtain the temperature characteristic constant, the initial indoor temperature, the previous indoor temperature, and the set temperature;

[0167] The desired indoor temperature at the current moment is determined based on the initial indoor temperature, the difference between the previous indoor temperature and the set temperature, the difference between the initial indoor temperature and the set temperature, and the time and temperature characteristic constants from the initial moment to the current moment.

[0168] In some embodiments, the desired indoor temperature at the current moment is determined using the following formula:

[0169] In the above formula: α, β, and γ are temperature characteristic constants, which are constants and are determined according to the room where the indoor unit is located.

[0170] τ n This is the current time value since the start of the cooling process, min;

[0171] T exp(n)Let be the desired indoor temperature at time n, in °C;

[0172] T i(n-1) Let be the indoor temperature at time n-1, in °C;

[0173] T i(0) The initial indoor temperature, in °C;

[0174] T s The set temperature is ℃.

[0175] The desired indoor temperature T at the current moment is determined based on the above formula for calculating the desired indoor temperature. exp(n) From the moment the air conditioning system starts operating, the desired indoor temperature T is calculated using the formula for calculating the desired indoor temperature at each current moment. exp(n) This is used to calculate the demand load of the target room.

[0176] The initial indoor temperature T at the initial moment can be used. i(0) The desired indoor temperature T at the initial moment exp(0) .

[0177] When the actual indoor temperature T i From the start of the cooling process, the initial temperature reaches the set temperature T. s After equalizing, make the desired indoor temperature T exp(n) Always equal to T s .

[0178] The desired method for calculating indoor temperature is to quickly and accurately approximate the set temperature, rapidly reducing the room temperature in the initial stage of cooling and slowing down in the later stage, thus precisely adjusting the room temperature to the set value.

[0179] In some embodiments, determining the current demand load based on cooling load parameters, the current indoor temperature, the current desired indoor temperature, the current outdoor temperature, and the control cycle includes: determining the current demand load based on cooling load parameters, the difference between the current indoor temperature and the current desired indoor temperature, the difference between the current outdoor temperature and the indoor temperature, and the control cycle.

[0180] After confirming the cooling load parameters a, b, and c and the desired indoor temperature T at the current moment... exp(n) Then, the current demand load Q of the target indoor unit is calculated based on the following demand load model. r(n) Q r(n) =a×(T) i(n) -T exp(n) )+b×(T a(n) -T i(n) )×t2+c×t2

[0181] In the above formula:

[0182] Q r(n) : Demand load at time n (current time), in kW;

[0183] a, b, c: Cooling load parameters, dimensionless units;

[0184] T i(n) : Indoor temperature at time n, in °C;

[0185] T exp(n) : The expected indoor temperature at time n, in °C;

[0186] T a(n) Outdoor ambient temperature at time n, in °C;

[0187] t2: Control period, min.

[0188] In the example in Figure 5, the method for determining the demand load at the current moment includes the following steps:

[0189] S51, Begin.

[0190] S52. Determine the cooling load parameters a, b, and c for the room corresponding to the indoor unit.

[0191] S53. Determine the desired indoor temperature T at the current moment according to the desired indoor temperature calculation formula. exp(n) .

[0192] S54. Based on the cooling load parameters a, b, c and the current indoor temperature T i(n) Compared with the current expected indoor temperature T exp(n) The difference between the current outdoor temperature T and the current outdoor temperature T a(n) Compared with the current indoor temperature T i(n) The difference and control cycle determine the current demand load Q. r(n) .

[0193] Determining the demand load based on cooling load parameters, the difference between indoor temperature and desired indoor temperature, and the difference between outdoor temperature and indoor temperature can improve the accuracy of demand load determination at the current moment.

[0194] The main operating parameters of an air conditioning system include compressor frequency and indoor unit fan speed.

[0195] The control of compressor frequency includes the control of compressor frequency at the initial moment and the real-time control of compressor frequency.

[0196] In some embodiments, the operating parameters include the compressor frequency at an initial moment, and the method for determining the compressor frequency at the initial moment includes the following steps:

[0197] Obtain the compressor characteristic parameter S;

[0198] Determine the initial demand load Q r(0) ;

[0199] Based on the compressor characteristic parameter S and the initial demand load Q r(0) The compressor frequency H0 at the initial moment is determined by the control period t.

[0200] The compressor frequency at the initial moment is determined based on the demand load at the initial moment, so that the compressor frequency at the initial moment meets the demand load requirements at the initial moment, thereby achieving rapid cooling in the initial stage of refrigeration.

[0201] Initial load demand: Q r(0) =a×(T) i(0) -T exp(0) )+b×(T a(0) -T i(0) )×t2+c×t2

[0202] compressor initial frequency:

[0203] In the above formula:

[0204] S: Compressor characteristic parameter, a constant, related to compressor specifications;

[0205] t2: Control cycle duration, in minutes;

[0206] x: a constant, for example: 2.8.

[0207] In a multi-split system, the initial demand load Q is... r(0) This is the sum of the load demands of all indoor units that are initially powered on. That is:

[0208] compressor initial frequency:

[0209] In the above formula:

[0210] S: Compressor characteristic parameter, a constant, related to compressor specifications;

[0211] g: Number of indoor units turned on;

[0212] Q rj(0) The initial load demand of the j-th indoor unit when the air conditioning system is turned on should be noted when Q... rj(0)

[0213] When < 0, the value is 0;

[0214] T ij(0) The indoor temperature (°C) of the j-th indoor unit at the initial moment when the air conditioning system is turned on;

[0215] T expj(0) The desired indoor temperature (°C) at the initial moment when the j-th indoor unit of the air conditioning system is turned on;

[0216] T a(0) The outdoor ambient temperature at the initial moment when the air conditioning system is turned on, in °C;

[0217] t2: Control cycle duration, in minutes;

[0218] x: a constant, for example: 2.8.

[0219] The target frequency of the compressor at the initial moment is controlled to be the compressor frequency at the initial moment.

[0220] In the example shown in Figure 6, the method for determining the compressor frequency at the initial moment includes the following steps:

[0221] S61, Begin.

[0222] S62. Obtain the control cycle, cooling load parameters of all indoor units in the system, initial indoor temperature, outdoor temperature, and desired indoor temperature.

[0223] S63. Calculate the initial load requirement of each indoor unit based on the control cycle, the cooling load parameters of each indoor unit, the initial indoor temperature, the outdoor temperature, and the desired indoor temperature.

[0224] S64. Calculate the initial load demand of all indoor units.

[0225] The initial load demand of all indoor units is the sum of the initial load demand of each indoor unit.

[0226] S65. Obtain compressor characteristic parameters.

[0227] S66. Determine the compressor frequency at the initial moment based on the compressor characteristic parameters, the initial demand load of all indoor units, and the control cycle.

[0228] Operating parameters include the compressor frequency at the current moment. The compressor frequency at the current moment is determined based on the current demand load, including:

[0229] Obtain the current actual evaporation temperature of the indoor unit;

[0230] The target evaporation temperature of the indoor unit is determined based on the current demand load and the current indoor temperature.

[0231] Obtain the compressor frequency, the actual evaporation temperature of the indoor unit, and the target evaporation temperature of the previous moment;

[0232] The compressor frequency at the current moment is determined based on the difference between the actual evaporation temperature of the indoor unit at the previous moment and the target evaporation temperature at the previous moment, the difference between the actual evaporation temperature of the indoor unit at the current moment and the target evaporation temperature at the current moment, and the compressor frequency at the previous moment.

[0233] The air conditioning system determines the current demand load, determines the target evaporation temperature based on the current demand load, and determines the current compressor frequency based on the difference between the current actual evaporation temperature and the target evaporation temperature, the difference between the previous actual evaporation temperature and the target evaporation temperature, and the compressor frequency of the previous moment. Therefore, the air conditioning system determines the current compressor operating frequency based on the change in demand load and the compressor frequency of the previous moment to achieve load following control, so that the operating capacity of the air conditioning system matches the demand load, thereby achieving smooth adjustment of the compressor frequency.

[0234] In some embodiments, determining the compressor frequency at the current moment based on the difference between the actual evaporation temperature of the indoor unit at the previous moment and the target evaporation temperature at the previous moment, the difference between the actual evaporation temperature of the indoor unit at the current moment and the target evaporation temperature at the current moment, and the compressor frequency at the previous moment includes:

[0235] Obtain the compressor characteristic parameter S, and the compressor iterative correction coefficients m1 and m2;

[0236] The compressor frequency at the current moment is calculated based on the following formula:

[0237] Among them, the compressor characteristic parameter S is a constant and is related to the compressor specifications;

[0238] The compressor iteration correction coefficients m1 and m2 are constants and are related to the compressor specifications.

[0239] H (n) The compressor frequency at the current moment;

[0240] H (n-1) The compressor frequency at the previous moment;

[0241] ΔT ep(n) This represents the difference between the current actual evaporation temperature of the indoor unit and the target evaporation temperature.

[0242] ΔT ep(n-1) This is the difference between the actual evaporation temperature of the indoor unit and the target evaporation temperature at the previous moment.

[0243] The compressor frequency is corrected by using the compressor characteristic parameter S and the compressor iterative correction coefficients m1 and m2 to improve the accuracy of compressor frequency determination.

[0244] In some embodiments, determining the target evaporation temperature of the indoor unit at the current moment based on the current demand load and the current indoor temperature includes: obtaining the model characteristic parameters of the indoor unit, and determining the target evaporation temperature of the indoor unit at the current moment based on the current indoor temperature, the current demand load, the model characteristic parameters of the indoor unit, and the control cycle.

[0245] The target evaporation temperature at the current moment is calculated as follows:

[0246] Among them, T eo The target evaporation temperature at the current moment;

[0247] T i(n) The current indoor temperature;

[0248] ζ HP This is a characteristic parameter of the indoor unit; this parameter is only related to the specifications of the indoor unit and has no dimensionless unit.

[0249] Q r(n) This represents the current demand load.

[0250] t2 is the duration of the control cycle.

[0251] The target evaporation temperature is determined by the current demand load, which is then used to further control the compressor frequency.

[0252] For a multi-split air conditioning system, for example, when multiple indoor units are turned on, the minimum of the target evaporation temperatures of the multiple indoor units at the current moment is determined as the target evaporation temperature at the current moment; the average of the actual evaporation temperatures of the multiple indoor units at the current moment is taken as the actual evaporation temperature.

[0253] The minimum target evaporation temperature of all operating indoor units is used as the target evaporation temperature to ensure that the determined compressor frequency can meet the demand load. The average of the current actual evaporation temperatures of multiple indoor units is used as the actual evaporation temperature to more accurately reflect the actual evaporation temperature of the multi-split system.

[0254] The method for determining the target evaporation temperature of a multi-split air conditioning system at the current moment is as follows:

[0255] Calculate the required load Q for each indoor unit j at the current moment n using the method described above. rj(n) Calculate the target evaporation temperature of each indoor unit j at the current time n:

[0256] In the above formula:

[0257] T ij(n) : The indoor temperature of the j-th indoor unit at time n, in °C;

[0258] ζ HP_j : The model characteristic parameters of the j-th indoor unit. These parameters are only related to the specifications of the indoor unit and have no dimensionless units.

[0259] t: Control cycle duration of the air conditioning system, in hours.

[0260] The target evaporation temperature T of the air conditioning system at the current moment eo(n) This is recorded as the minimum target evaporation temperature of all indoor units in the system at the current moment.

[0261] Calculate the average value T of the actual evaporation temperature of the indoor unit in the system at the current moment. lave(n) .

[0262] The compressor frequency H at the current moment (i.e., the nth moment) (n) : ΔT ep(n) =T lave(n) -T eo(n)

[0263] In the above formula:

[0264] T lave(n) : The average actual evaporation temperature of the indoor unit in the system at the current moment, in °C;

[0265] m1, m2: Compressor frequency iteration correction coefficients, constants;

[0266] S: Compressor characteristic parameter, a constant, related to compressor specifications;

[0267] ΔT ep(n-1) You can refer to ΔT ep(n) The calculation is performed using the formula.

[0268] In the example in Figure 7, the compressor control method at the current moment is:

[0269] S71, Begin.

[0270] S72. Obtain the actual evaporation temperature of the indoor unit at the current moment.

[0271] When multiple indoor units are turned on, the average of the actual evaporation temperatures of the multiple indoor units at the current moment is taken as the actual evaporation temperature.

[0272] S73. Determine the target evaporation temperature of the indoor unit at the current moment based on the current demand load and indoor temperature.

[0273] When multiple indoor units are turned on, the minimum value of the target evaporation temperature of the multiple indoor units at the current moment is determined as the target evaporation temperature at the current moment.

[0274] S74. Calculate the difference between the actual evaporation temperature of the indoor unit and the target evaporation temperature at the current moment.

[0275] S75. Obtain the compressor frequency, actual evaporation temperature of the indoor unit, and target evaporation temperature of the previous moment; obtain the compressor characteristic parameter S, compressor iteration correction coefficient m, and compressor iteration correction coefficient n.

[0276] S76. Calculate the compressor frequency at the current moment.

[0277] The indoor unit fan speed is determined based on the current demand load, including:

[0278] Obtain the capacity characteristic coefficient of the indoor unit and the current demand load. Determine the compressor frequency correction coefficient based on the current demand load, the capacity characteristic coefficient of the indoor unit, and the control cycle. Determine the indoor unit fan damper based on the compressor frequency correction coefficient. The indoor fan damper is positively correlated with the compressor frequency correction coefficient.

[0279] In some embodiments, when a specific fan speed control signal is received, the indoor fan speed is controlled to operate at the specified speed.

[0280] When no definite fan speed control signal is received, the indoor unit fan speed is determined based on the compressor frequency correction coefficient, and the indoor fan speed is positively correlated with the compressor frequency correction coefficient.

[0281] The methods for determining the compressor frequency correction factor include:

[0282] Obtain the capacity characteristic coefficient of the indoor unit and the current demand load. Based on the current demand load, the capacity characteristic coefficient of the indoor unit, and the control cycle, determine the compressor frequency correction coefficient as follows:

[0283] In the above formula:

[0284] K comp(n) : Compressor frequency correction coefficient at time n. It should be noted that when the calculation result K... comp(n) When < 0, the value is 0;

[0285] V HP The capacity characteristic coefficient of the indoor unit is a constant, which is related to the capacity and specifications of the indoor unit.

[0286] x: a constant, for example: 2.8.

[0287] The indoor fan speed is adjusted according to the current demand load to further ensure that the indoor unit can meet the demand load.

[0288] Control of the initial fan speed of the indoor fan includes:

[0289] When no definitive fan speed control signal is received, the initial fan speed F0 of the indoor fan is determined based on the compressor frequency correction factor K at the initial moment. comp(0) Determine the initial fan speed F0 of the indoor fan and the compressor frequency correction factor K at the initial moment. comp(0) Positive correlation.

[0290] Initial compressor frequency correction factor:

[0291] Initially, the initial fan speed F0 needs to be set according to the application or operating status of the air conditioning system. If the user has set a specific fan speed, the initial fan speed F0 uses the user-set specific fan speed. If the user has set a free fan speed or has not set a fan speed, in some embodiments, the initial fan speed F0 is set according to the following table:

[0292] The indoor fan has 6 speed settings, based on the initial K... comp(0) The value determines the initial fan speed F0 of the indoor fan.

[0293] In the example shown in Figure 8, the method for determining the initial fan speed of the indoor fan is as follows:

[0294] S81, Begin.

[0295] S82. Determine if the user has set a specific fan speed. If yes, proceed to step S3; otherwise, proceed to step S4.

[0296] S83. Operate according to the user-defined fan speed.

[0297] S84. Determine the compressor frequency correction coefficient K at the initial moment. comp(0) .

[0298] S85. Determine the initial fan speed corresponding to the compressor frequency correction coefficient at the initial moment.

[0299] Real-time control of indoor fan speed:

[0300] The real-time fan speed of the indoor fan is determined based on the real-time compressor frequency correction coefficient, and the real-time fan speed of the indoor fan is positively correlated with the real-time compressor frequency correction coefficient.

[0301] In a multi-split air conditioning system, the compressor frequency correction factor for the j-th indoor unit at the current time (n) is:

[0302] Q rj(n) The demand load of the j-th indoor unit of the air conditioning system at the current moment after it is turned on;

[0303] V HPj : Capacity characteristic coefficient of the j-th indoor unit in the system, a constant, which is related to the capacity and specifications of the indoor unit;

[0304] T expj(n) Let be the desired indoor temperature of the j-th indoor unit at the current moment, in °C;

[0305] T ij(n) : represents the current indoor temperature of the j-th indoor unit, in °C;

[0306] T a(n) : The current outdoor temperature, in °C.

[0307] In some embodiments, the fan speed of the j-th indoor unit at the current moment is set according to the following table:

[0308] The indoor fan has 6 speed settings, depending on the real-time K... compj(n) The value determines whether the fan speed needs to be changed at the current moment to meet the actual performance requirements of the indoor unit.

[0309] In the example shown in Figure 9, the method for controlling the indoor unit's fan speed at the current moment includes the following steps:

[0310] S91, Begin.

[0311] S92. Determine the compressor frequency correction coefficient at the current moment.

[0312] S93. Determine the indoor fan speed corresponding to the compressor frequency correction coefficient at the current moment.

[0313] S94. Adjust the indoor unit fan speed to the current indoor unit fan speed.

[0314] In some embodiments, steps S2-S4 are repeated at certain time intervals.

[0315] The operating parameters of the air conditioning system also include the opening degree of the indoor expansion valve. The opening degree control of the indoor expansion valve is related to the real-time superheat value of the indoor unit. The real-time superheat value of the indoor unit is obtained by detection and calculation under the above-mentioned demand load control method.

[0316] In some embodiments, the method for controlling the opening of the indoor expansion valve includes: determining the real-time superheat value of the indoor unit; when the real-time superheat value is below a set value, the opening of the indoor expansion valve remains unchanged; when the real-time superheat value is above the set value, the opening of the indoor expansion valve is increased.

[0317] In some embodiments, the value is set to 0.

[0318] Determine the superheat value SH of the j-th indoor unit. j If the superheat value SH j If ≤0, then maintain the opening value EXV of the indoor expansion valve. j Unchanged; if the superheat value SHj If the value is greater than 0, then the opening degree EXV of the electronic expansion valve of the indoor unit will be increased. j value.

[0319] By adjusting the opening of the indoor expansion valve, the real-time superheat is kept below the set value to ensure the normal operation of the compressor and the evaporation capacity of the indoor unit.

[0320] In some embodiments, the method for determining the increase in the opening degree of the indoor expansion valve includes the following steps:

[0321] Obtain the overheating iterative correction coefficient;

[0322] The first difference is calculated as the difference in superheat between the current moment and the previous moment.

[0323] The difference in superheat between the previous moment and the moment before that is calculated as the second difference.

[0324] The increase in the opening of the indoor expansion valve is determined based on the first difference, the difference between the first and second differences, and the superheat correction coefficient.

[0325] The method for determining the increase in the opening of the indoor expansion valve can ensure that the opening of the indoor expansion valve is adjusted smoothly and continuously.

[0326] In some embodiments, the opening degree of the indoor expansion valve of the j-th indoor unit at the previous moment is EXV. j(n-1) Then the current opening degree of the indoor expansion valve EXV j(n) The calculation method is as follows: ΔSH j(n) =SH j(n) -SH j(n-1)

[0327] In the above formula: r1, r2, C SH : Superheat iteration correction coefficient, a constant, related to the indoor unit specifications;

[0328] SH j(n) The superheat at the outlet of the j-th indoor unit at time n;

[0329] SH j(n-1) The superheat at the outlet of the j-th indoor unit at time n-1;

[0330] ΔSH j(n-1) Please refer to ΔSH j(n) The calculation formula is used to obtain the result.

[0331] In the example shown in Figure 10, the control method for the indoor expansion valve is as follows:

[0332] S101, Begin.

[0333] S102, Control the expansion valve in the control room to its initial opening.

[0334] S103, Calculate the superheat value SH of the indoor unit. i .

[0335] S104. Determine the superheat value SH i Is it less than or equal to 0? If yes, proceed to step S105; otherwise, proceed to step S106.

[0336] S105. Keep the opening of the indoor expansion valve unchanged. Proceed to step S103.

[0337] S106. Increase the opening of the indoor expansion valve. Proceed to step S103.

[0338] In a multi-split air conditioning system, the initial opening of the indoor expansion valve is determined based on the maximum opening of the indoor expansion valve of the current indoor unit and the ratio of the capacity of the currently running indoor unit to the total capacity of all running indoor units.

[0339] The initial opening of the indoor expansion valve determined by the above method makes the refrigerant distribution more reasonable.

[0340] In some embodiments, control of the initial opening of the indoor expansion valve:

[0341] The initial opening degree of the indoor expansion valve of the j-th indoor unit:

[0342] In the above formula:

[0343] EXV maxj : The maximum opening value of the j-th indoor expansion valve;

[0344] VO j : Capacity of the j-th indoor unit, in HP;

[0345] The total capacity of the indoor units in the system when they are turned on, in HP;

[0346] C b : Mode correction parameter, dimensionless parameter, related to specific function selection options.

[0347] When the air conditioning system is started, adjust the opening of the indoor expansion valve to the initial opening of the indoor expansion valve mentioned above.

[0348] The air conditioning system learns the load characteristics of a predetermined target building based on the indoor unit's operating capacity calculation algorithm. After obtaining the load characteristic parameters of the target building, it establishes a load model and uses the building's demand load as the control target of the control system. Based on the demand load, it obtains the initial control parameters of the air conditioning system in the cooling mode and the control parameters of the load following control process.

[0349] First, determine the initial control parameters of the air conditioning system. Then, adjust the current control parameters based on the real-time demand load and the control parameters of the multi-split unit at the previous moment. This will enable rapid cooling in the early stages of the cooling process to improve comfort, and reduce room temperature fluctuations under medium and low loads to avoid increased power consumption due to frequent start-stop cycles.

[0350] The control method of adjusting the compressor, expansion valve and fan speed based on the actual load demand of the building can match the air conditioning capacity with the actual load of the building and solve the problems of over- or under-utilization of indoor unit capacity.

[0351] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0352] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for controlling an air conditioning system, comprising: The cooling load parameters of the corresponding room for the indoor unit are determined based on historical learning data and load characteristic learning models. The historical learning data includes indoor temperature, set temperature, outdoor temperature, and indoor unit capabilities at several historical moments. Get the current indoor temperature and the current outdoor temperature; Determine the desired indoor temperature at the current moment; The demand load at the current moment is determined based on the cooling load parameters, the current indoor temperature, the current desired indoor temperature, the current outdoor temperature, and the control cycle. The operating parameters of the air conditioning system are determined based on the demand load at the current moment.

2. The control method for the air conditioning system according to claim 1, wherein, The load feature learning model is expressed by the following formula: Q e =a×(T i -T s )+b×(T a -T i )×t1+c×t1 Among them, Q e The indoor unit's capacity is represented by a, b, and c; these are the cooling load parameters; T i Indoor temperature; T s To set the temperature; T a t1 represents the outdoor temperature; t1 represents the learning step size. The determination of the current demand load based on cooling load parameters, current indoor temperature, current desired indoor temperature, current outdoor temperature, and control cycle includes determining the current demand load based on the following formula: Q r(n) =a×(T i(n) -T exp(n) )+b×(T a(n) -T i(n) )×t2+c×t2 Among them, Q r(n) T represents the current demand load; i(n) The current indoor temperature; T exp(n) The desired indoor temperature; T a(n) The outdoor temperature at the current moment; T i(n) t1 represents the indoor temperature; t2 represents the control cycle.

3. The control method for the air conditioning system according to claim 1, wherein, Determining the desired indoor temperature at the current moment includes: Obtain the temperature characteristic constant, the initial indoor temperature, the previous indoor temperature, and the set temperature; The desired indoor temperature at the current moment is determined based on the initial indoor temperature, the difference between the previous indoor temperature and the set temperature, the difference between the initial indoor temperature and the set temperature, the time from the initial moment to the current moment, and the temperature characteristic constant.

4. The control method for an air conditioning system according to any one of claims 1-3, wherein, The operating parameters include the compressor frequency at the current moment, and determining the compressor frequency at the current moment based on the current demand load includes: Obtain the current actual evaporation temperature of the indoor unit; The target evaporation temperature of the indoor unit at the current moment is determined based on the current demand load and the current indoor temperature. Obtain the compressor frequency, the actual evaporation temperature of the indoor unit, and the target evaporation temperature of the previous moment; The compressor frequency at the current moment is determined based on the difference between the actual evaporation temperature of the indoor unit at the previous moment and the target evaporation temperature at the previous moment, the difference between the actual evaporation temperature of the indoor unit at the current moment and the target evaporation temperature at the current moment, and the compressor frequency at the previous moment.

5. The control method for an air conditioning system according to claim 4, wherein, The step of determining the compressor frequency at the current moment based on the difference between the actual evaporation temperature of the indoor unit at the previous moment and the target evaporation temperature at the previous moment, the difference between the actual evaporation temperature of the indoor unit at the current moment and the target evaporation temperature at the current moment, and the compressor frequency at the previous moment includes: Obtain the compressor characteristic parameter S, and the compressor iterative correction coefficients m1 and m2; The compressor frequency at the current moment is calculated based on the following formula: Among them, H (n) The compressor frequency at the current moment; H (n-1) The compressor frequency at the previous moment; ΔT ep(n) This represents the difference between the current actual evaporation temperature of the indoor unit and the target evaporation temperature. ΔT ep(n-1) This is the difference between the actual evaporation temperature of the indoor unit and the target evaporation temperature at the previous moment.

6. The control method for the air conditioning system according to claim 4, wherein, The step of determining the target evaporation temperature of the indoor unit at the current moment based on the current demand load and the current indoor temperature includes: obtaining the model characteristic parameters of the indoor unit, and determining the target evaporation temperature of the indoor unit at the current moment based on the current indoor temperature, the current demand load, the model characteristic parameters of the indoor unit, and the control cycle.

7. The control method for an air conditioning system according to claim 6, wherein, When the air conditioning system includes multiple indoor units that are turned on, the minimum value of the target evaporation temperature of the multiple indoor units at the current moment is determined as the target evaporation temperature at the current moment; the average value of the actual evaporation temperature of the multiple indoor units at the current moment is taken as the actual evaporation temperature.

8. The control method for an air conditioning system according to any one of claims 1-3, wherein, The operating parameters include the compressor frequency at the initial moment. Determining the compressor frequency at the initial moment based on the demand load at the initial moment includes: Obtain compressor characteristic parameters; Determine the initial demand load; The compressor frequency at the initial moment is determined based on the compressor characteristic parameters, the demand load at the initial moment, and the control cycle.

9. The control method for an air conditioning system according to any one of claims 1-3, wherein, The operating parameters include the indoor unit fan speed, and determining the indoor unit fan speed based on the current demand load includes: The capacity characteristic coefficient of the indoor unit and the demand load at the current moment are obtained. The compressor frequency correction coefficient is determined based on the demand load at the current moment, the capacity characteristic coefficient of the indoor unit, and the control cycle. The indoor unit fan baffle is determined based on the compressor frequency correction coefficient. The indoor fan baffle is positively correlated with the compressor frequency correction coefficient.

10. The control method for an air conditioning system according to any one of claims 1-3, wherein, The air conditioning system includes an indoor expansion valve. The method for controlling the opening degree of the indoor expansion valve includes: determining the real-time superheat value of the indoor unit; when the real-time superheat value is below a set value, the opening degree of the indoor expansion valve remains unchanged; when the real-time superheat value is above the set value, the opening degree of the indoor expansion valve is increased. The method for determining the amount of increase in the opening degree of the indoor expansion valve includes: Obtain the overheating iterative correction coefficient; The first difference is calculated as the difference in superheat between the current moment and the previous moment. The difference in superheat between the previous moment and the moment before that is calculated as the second difference. The increase in the opening of the indoor expansion valve is determined based on the first difference, the difference between the first difference and the second difference, and the superheat iterative correction coefficient.

Images