Piping length recognition method, device and medium for multi-connected air conditioning system

Abstract

The application provides a multi-connected air conditioner system pipe length identification method, device and medium, wherein the identification method comprises the following steps: acquiring the inner diameters and flow areas of the outer machine connecting pipe, the inner machine connecting pipe and the total connecting pipe, and the inner diameter of the branch pipe; then acquiring the pressure drop of the air conditioner outer machine, the unit length pressure drop of the inner machine connecting pipe, the unit length pressure drop of the total connecting pipe and the unit length pressure drop of the branch pipe according to the acquired inner diameter of the branch pipe and the inner diameters and flow areas of the outer machine connecting pipe, the inner machine connecting pipe and the total connecting pipe, and obtaining the total pipe pressure drop of the multi-connected air conditioner system according to the system total pressure drop of the multi-connected air conditioner system and the pressure drop of the air conditioner outer machine; finally, calculating the corresponding multi-connected pipe length of each air conditioner inner machine according to the unit length pressure drops of the inner machine connecting pipe, the total connecting pipe and the branch pipe, the preset length of each air conditioner inner machine and the total pipe pressure drop. The technical scheme provided by the application can improve the accuracy of the connection pipe length identification.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pipe length identification of a multi-connected air conditioning system, and particularly relates to a pipe length identification method, device and medium of a multi-connected air conditioning system. BACKGROUND

[0002] The multi-connected air conditioning system refers to an air conditioning system in which multiple air conditioner indoor units and multiple air conditioner outdoor units are arranged, and the multiple air conditioner indoor units and the multiple air conditioner outdoor units are connected into a refrigeration cycle mechanism through connected pipes. Since different specifications of air conditioner indoor units can be used in the multi-connected air conditioning system to meet different application scenarios, and multiple air conditioner outdoor units are used to provide sufficient outdoor unit capacity, the multi-connected air conditioning system can meet the needs of various application scenarios and has the advantage of strong applicability.

[0003] With the development of control technology and air conditioner oil return technology, the total capacity of the outdoor units in the multi-connected air conditioning system is getting larger and larger. Correspondingly, the length of the connected pipes between the air conditioner outdoor units and the air conditioner indoor units is also getting larger and larger. The length of the connected pipes causes a loss of pressure between the air conditioner outdoor units and the air conditioner indoor units, which in turn causes the refrigeration and heating effects of the multi-connected air conditioning system to decrease, and reduces the operating efficiency of the multi-connected air conditioning system. Therefore, in order to improve the reliability of the control of the multi-connected air conditioning system, it is necessary to accurately obtain the length of the connected pipes of each air conditioner indoor unit in the multi-connected air conditioning system.

[0004] In the prior art, the length of the connected pipes in the multi-connected air conditioning system is obtained by directly measuring the length using a length measuring device. For example, an ultrasonic wave generator and an ultrasonic wave receiver can be arranged at both ends of the connected pipe. The ultrasonic wave generator emits an ultrasonic wave signal at one end of the connected pipe, and the ultrasonic wave receiver receives the ultrasonic wave signal at the other end of the connected pipe. The length of the connected pipe is obtained by the time length of the propagation of the ultrasonic wave signal in the connected pipe. However, when the multi-connected air conditioning system is assembled, the air conditioner indoor units and the air conditioner outdoor units are located indoors and outdoors respectively. When the length of the connected pipe is directly measured using the length measuring device, there is a problem of inconvenience in operation, which causes a large error in the measurement result.

[0005] As described above, in the prior art, when the length of the connected pipe in the multi-connected air conditioning system is obtained, there is a problem of poor accuracy of the obtained result. SUMMARY

[0006] In view of the above problems, the present application provides a pipe length identification method, device and medium of a multi-connected air conditioning system to overcome the above problems or at least partially solve the problem of poor accuracy of the obtained result when the length of the connected pipe in the multi-connected air conditioning system is obtained, so as to accurately obtain the length of the connected pipe in the multi-connected air conditioning system.

[0007] To at least solve the above technical problems, the present application provides the following technical solutions:

[0008] A pipe length identification method of a multi-connected air conditioning system, the multi-connected air conditioning system comprising an air conditioner outdoor unit, an air conditioner indoor unit, and a pipe system connecting the air conditioner outdoor unit and the air conditioner indoor unit; the pipe system comprising an outdoor unit connecting pipe connected to the air conditioner outdoor unit, a total connecting pipe in communication with the outdoor unit connecting pipe, a branch pipe connected to the total connecting pipe, and an indoor unit connecting pipe connected to the branch pipe and the air conditioner indoor unit; the pipe length identification method comprising:

[0009] obtaining the inner diameter of the branch pipe, and obtaining the inner diameters and flow areas of the outdoor unit connecting pipe, the indoor unit connecting pipe, and the total connecting pipe;

[0010] obtaining the pressure drop of the air conditioner outdoor unit according to the inner diameter and flow area of the outdoor unit connecting pipe;

[0011] obtaining the unit length pressure drop of the indoor unit connecting pipe according to the inner diameter and flow area of the indoor unit connecting pipe;

[0012] obtaining the unit length pressure drop of the total connecting pipe according to the inner diameter and flow area of the total connecting pipe;

[0013] obtaining the unit length pressure drop of the branch pipe according to the inner diameter of the branch pipe and the inner diameter and unit length pressure drop of the indoor unit connecting pipe;

[0014] obtaining the system total pressure drop of the multi-connected air conditioning system, and obtaining the pipe total pressure drop of the multi-connected air conditioning system according to the system total pressure drop of the multi-connected air conditioning system and the pressure drop of the air conditioner outdoor unit;

[0015] obtaining the preset length of the air conditioner indoor unit, and calculating the corresponding multi-connected pipe length of the air conditioner indoor unit according to the unit length pressure drops of the indoor unit connecting pipe, the total connecting pipe, and the branch pipe, the preset length of each air conditioner indoor unit, and the pipe total pressure drop.

[0016] According to an embodiment of the present application, the obtaining the inner diameter of the branch pipe, and obtaining the inner diameters and flow areas of the outdoor unit connecting pipe, the indoor unit connecting pipe, and the total connecting pipe comprises:

[0017] obtaining the model of the air conditioner indoor unit and the model of the air conditioner outdoor unit;

[0018] obtaining the inner diameter and flow area of the total connecting pipe, and the total capacity of the air conditioner outdoor unit according to the model of the air conditioner outdoor unit;

[0019] obtaining the inner diameter and flow area of the total connecting pipe according to the total capacity of the air conditioner outdoor unit;

[0020] According to the model of the air conditioner indoor unit, the inner diameter and flow area of ​​the indoor unit connecting pipe and the capacity of the air conditioner indoor unit are obtained;

[0021] The inner diameter of the branch pipe is obtained according to the capacity of the air conditioner indoor unit.

[0022] According to one embodiment of the present invention, obtaining the pressure drop of the outdoor unit of the air conditioner according to the inner diameter and flow area of ​​the outdoor unit connecting pipe includes:

[0023] Obtaining the system refrigerant flow rate, the local resistance coefficient of the outdoor unit connecting pipe, and the refrigerant density;

[0024] Obtaining an average mass flow density of the external unit connecting pipe according to the system refrigerant flow rate and the flow area of ​​the external unit connecting pipe;

[0025] The pressure drop of the outdoor unit of the air conditioner is obtained according to the average mass flow density, the local resistance coefficient and the density of the refrigerant of the outdoor unit connecting pipe.

[0026] According to one embodiment of the present invention, obtaining the pressure drop per unit length of the internal machine connecting pipe according to the inner diameter and flow area of ​​the internal machine connecting pipe includes:

[0027] Obtaining the system refrigerant flow rate, refrigerant density, and friction factor of the internal unit connecting pipe;

[0028] According to the inner diameter and flow area of ​​each internal machine connecting pipe, the total inner diameter and total flow area of ​​the internal machine connecting pipe are obtained;

[0029] Obtaining a mass flow density of the internal unit connecting pipe according to the system refrigerant flow rate and the total flow area of ​​the internal unit connecting pipe;

[0030] The pressure drop per unit length of the internal unit connecting pipe is obtained according to the friction factor, the total inner diameter, the mass flow density and the refrigerant density of the internal unit connecting pipe.

[0031] According to one embodiment of the present invention, obtaining the pressure drop per unit length of the main connecting pipe according to the inner diameter and flow area of ​​the main connecting pipe includes:

[0032] Obtaining the system refrigerant flow rate, refrigerant density, and friction factor of the main connecting pipe;

[0033] Obtaining a mass flow density of the total connecting pipe according to the system refrigerant flow rate and the flow area of ​​the total connecting pipe;

[0034] The pressure drop per unit length of the main connecting pipe is calculated according to the friction factor, inner diameter, mass flow density and refrigerant density of the main connecting pipe.

[0035] According to one embodiment of the present application, the unit length pressure drop of the branch pipe is obtained according to the inner diameter and unit length pressure drop of the inner machine connecting pipe and the inner diameter of the branch pipe, which comprises:

[0036] The number of starting of the air conditioner inner machine is obtained.

[0037] When the number of starting of the air conditioner inner machine is one, the unit length pressure drop of the branch pipe is obtained according to the inner diameter and unit length pressure drop of the inner machine connecting pipe and the inner diameter of the branch pipe.

[0038] When the number of starting of the air conditioner inner machine is more than one, the unit length pressure drop of the branch pipe is obtained according to the inner diameter and unit length pressure drop of the inner machine connecting pipe, the inner diameter of the branch pipe and the number of starting of the air conditioner inner machine.

[0039] According to one embodiment of the present application, the online pipe length corresponding to each air conditioner inner machine is calculated according to the unit length pressure drop of the inner machine connecting pipe, the total connecting pipe and the branch pipe, the preset length of each air conditioner inner machine and the total pressure drop of the pipe, which comprises:

[0040] The equivalent unit length pressure drop is obtained according to the unit length pressure drop of the total connecting pipe and the unit length pressure drop of the branch pipe.

[0041] The uncertainty caused by the inner machine connecting pipe is calculated according to the unit length pressure drop of the inner machine connecting pipe and the equivalent unit length pressure drop.

[0042] The determined length of each inner machine connecting pipe is calculated according to the total pressure drop of the pipe, the preset length of the inner machine connecting pipe, the unit length pressure drop of the inner machine connecting pipe, the equivalent unit length pressure drop.

[0043] The online pipe length corresponding to each air conditioner inner machine is calculated according to the uncertainty caused by the inner machine connecting pipe corresponding to each air conditioner inner machine and the determined length of each inner machine connecting pipe.

[0044] According to one embodiment of the present application, the equivalent unit length pressure drop is obtained according to the unit length pressure drop of the total connecting pipe and the unit length pressure drop of the branch pipe, which comprises:

[0045] The weight of the total connecting pipe and the weight of the branch pipe are obtained.

[0046] The unit length pressure drop of the total connecting pipe and the unit length pressure drop of the branch pipe are weighted according to the weight of the total connecting pipe and the weight of the branch pipe, so as to obtain the equivalent unit length pressure drop.

[0047] A piping length identification device of a multi-split air conditioning system, comprising a processor and a memory, the memory storing computer program instructions which, when executed by the processor, implement the multi-split air conditioning system piping length identification method of any one of the above embodiments.

[0048] A computer readable storage medium storing computer program instructions which, when executed by a processor, implement the multi-split air conditioning system piping length identification method of any one of the above embodiments.

[0049] The technical solution provided by the present application first acquires the inner diameter of the branch pipe and the inner diameters and flow areas of the outdoor unit connecting pipe, the indoor unit connecting pipe and the total connecting pipe, then acquires the pressure drop of the outdoor unit, the unit length pressure drop of the indoor unit connecting pipe, the unit length pressure drop of the total connecting pipe and the unit length pressure drop of the branch pipe according to the acquired inner diameter of the branch pipe and the inner diameters and flow areas of the outdoor unit connecting pipe, the indoor unit connecting pipe and the total connecting pipe, and obtains the total pressure drop of the multi-split air conditioning system according to the system total pressure drop and the pressure drop of the outdoor unit; finally, the length of the indoor unit connecting pipe corresponding to the indoor unit is calculated according to the unit length pressure drops of the indoor unit connecting pipe, the total connecting pipe and the branch pipe, the preset length of the indoor unit and the total pressure drop of the piping.

[0050] The above and other objects, advantages and features of the present application will become more apparent from the following detailed description of some embodiments thereof, when considered in conjunction with the annexed drawings in which: BRIEF DESCRIPTION OF DRAWINGS

[0051] Some specific embodiments of the present application will be described in detail below with reference to the attached drawings, which are provided by way of example and without limitation. The same reference numbers in the drawings indicate the same or similar components or parts. It should be understood by those skilled in the art that the drawings are not necessarily drawn to scale. In the drawings:

[0052] Figure 1 is a structural schematic diagram of a first perspective view of a multi-split air conditioning system according to an embodiment of the present application;

[0053] Figure 2 is a flowchart of a multi-split air conditioning system piping length identification method according to an embodiment of the present application;

[0054] Figure 3is a flowchart of acquiring the inner diameter and the flow area of the outer machine connecting pipe, the inner machine connecting pipe, the total connecting pipe and the branch pipe according to an embodiment of the present application;

[0055] Figure 4 is a flowchart of obtaining the pressure drop of the air conditioner outer machine according to the inner machine and the flow area of the outer machine connecting pipe according to an embodiment of the present application;

[0056] Figure 5 is a flowchart of obtaining the pressure drop per unit length of the total connecting pipe according to the inner diameter and the flow area of the total connecting pipe according to an embodiment of the present application;

[0057] Figure 6 is a flowchart of obtaining the pressure drop per unit length of the inner machine connecting pipe according to the inner diameter and the flow area of the inner machine connecting pipe according to an embodiment of the present application;

[0058] Figure 7 is a flowchart of obtaining the pressure drop per unit length of the branch pipe according to the inner diameter and the flow area of the branch pipe according to an embodiment of the present application;

[0059] Figure 8 is a flowchart of calculating the total length of the pipe according to the pressure drop per unit length of the inner machine connecting pipe, the total connecting pipe and the branch pipe and the total pressure drop of the pipe according to an embodiment of the present application;

[0060] Figure 9 is a structural schematic diagram of a pipe length identification device of a multi-split air conditioning system according to an embodiment of the present application. DETAILED DESCRIPTION

[0061] The pipe length identification method of a multi-split air conditioning system, the pipe length identification device of a multi-split air conditioning system and the computer readable storage medium of an embodiment of the present application will be described below with reference to Figures 1 to 9 In the description of the present embodiment, it should be understood that the terms "first", "second" are used only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features, that is, one or more of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically limited. When a certain feature "includes or contains" a certain or certain features, unless otherwise specifically described, it indicates that other features are not excluded and can further include other features.

[0062] Unless otherwise defined, the terms "set", "mount", "connected", "connecting", "fixed", "coupling" and the like are to be construed in their broadest possible sense, such as to include fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections, or connections through intermediate media; direct connections, or indirect connections; or connections between internal components of two elements, or the interaction between two elements, unless otherwise explicitly defined. Those skilled in the art should be able to understand the specific meaning of the above terms in the present application according to the specific circumstances.

[0063] In addition, in the description of the present embodiment, the first feature "on" or "under" the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. That is, in the description of the present embodiment, the first feature "on", "above" and "over" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the first feature is higher in horizontal height than the second feature. The first feature "under", "below" or "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the first feature is lower in horizontal height than the second feature.

[0064] In the description of the present embodiment, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the exemplary description of the above terms does 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.

[0065] Please refer to Figure 1 , Figure 1 is a structural schematic view of a first perspective of a multi-split air conditioning system. Figure 1The illustrated multi-connected air conditioning system includes an outdoor unit and an indoor unit, wherein the outdoor unit has a plurality of air conditioning outdoor units 11, and the indoor unit has a plurality of air conditioning indoor units 21, each air conditioning outdoor unit 11 is arranged outdoors, and each air conditioning indoor unit 21 is arranged indoors. The air conditioning outdoor unit 11 is connected to the total connecting pipe 32 through the outdoor connecting pipe 31 and the intermediate pipe; the total connecting pipe 32 is connected to each air conditioning indoor unit 21 through the branch pipe 33 and the indoor connecting pipe 34 of each air conditioning indoor unit 21. The intermediate pipe can also adopt a branch pipe or a similar branch or convergence structure. Since the intermediate pipe is relatively short, in the following control method, the related parameters of the intermediate pipe are not considered, of course, the parameters of the intermediate pipe can also be considered according to the corresponding control principle. In some embodiments of the present application, the air conditioning outdoor unit 11 is directly connected to the total connecting pipe 32 through the outdoor connecting pipe 31, and there is no intermediate pipe.

[0066] Figure 2 The illustrated is a flow chart of a pipe length identification method of a multi-connected air conditioning system of the present application, which is suitable for Figure 1 identifying the lengths of the connected pipes corresponding to each air conditioning indoor unit 21 in the multi-connected air conditioning system. The following flow chart illustrated in Figure 2 will be used to introduce the pipe length identification method of the multi-connected air conditioning system of the present application in detail.

[0067] As shown in Figure 2 , the pipe length identification method of the multi-connected air conditioning system of the present application includes:

[0068] Step S1: obtaining the inner diameter of the branch pipe 33, and obtaining the inner diameters and flow areas of the outdoor connecting pipe 31, the indoor connecting pipe 34 and the total connecting pipe 32;

[0069] Step S2: obtaining the pressure drop of the air conditioning outdoor unit 11 according to the inner diameter and flow area of the outdoor connecting pipe 31, obtaining the unit length pressure drop of the indoor connecting pipe 34 according to the inner diameter and flow area of the indoor connecting pipe 34, obtaining the unit length pressure drop of the total connecting pipe 32 according to the inner diameter and flow area of the total connecting pipe 32, and obtaining the unit length pressure drop of the branch pipe 33 according to the inner diameter of the branch pipe 33 and the unit length pressure drop of the indoor connecting pipe 34;

[0070] Step S3: obtaining the system total pressure drop of the multi-connected air conditioning system, and obtaining the pipe total pressure drop of the multi-connected air conditioning system according to the system total pressure drop of the multi-connected air conditioning system and the pressure drop of the air conditioning outdoor unit 11;

[0071] Step S4: obtaining the preset length of each air conditioning indoor unit 21, and calculating the length of the connected pipe corresponding to each air conditioning indoor unit 21 according to the unit length pressure drops of the indoor connecting pipe 34, the total connecting pipe 32 and the branch pipe 33, the preset length of each air conditioning indoor unit 21 and the pipe total pressure drop.

[0072] In the step S1, the inner diameter and the flow area of the outdoor unit connecting pipe 31 and the total connecting pipe 32 can be determined according to the specifications of the air conditioner outdoor unit 11, the inner diameter and the flow area of the indoor unit connecting pipe 34 can be determined according to the specifications of the air conditioner indoor unit 21, and the inner diameter and the flow area of the branch pipe 33 can be determined according to the specifications of the air conditioner indoor unit 21.

[0073] In the step S2, the pressure drop of the air conditioner outdoor unit 11 refers to the pressure drop lost at the air conditioner outdoor unit 11, which can be obtained according to the inner diameter and the flow area of the outdoor unit connecting pipe 31. The unit length pressure drop refers to the pressure lost in a unit length. In the present example, the unit length pressure drop of the total connecting pipe 32 can be obtained according to the inner diameter and the flow area of the total connecting pipe 32, the unit length pressure drop of the indoor unit connecting pipe 34 can be obtained according to the inner diameter and the flow area of the indoor unit connecting pipe 34, and the unit length pressure drop of the branch pipe 33 can be obtained according to the inner diameter of the branch pipe 33, the inner diameter of the indoor unit connecting pipe 34, and the unit length pressure drop of the indoor unit connecting pipe 34.

[0074] In the step S3, the system total pressure drop of the multi-split air conditioner can be obtained by detection. For example, the system total pressure provided by the plurality of air conditioner outdoor units 11 can be obtained first, and then the pressure at the air conditioner indoor unit 21 can be detected by a pressure sensor. The system total pressure drop of the multi-split air conditioner can be calculated by subtracting the pressure at the air conditioner indoor unit 21 from the system total pressure provided by the plurality of air conditioner outdoor units 11. Since the system total pressure drop of the multi-split air conditioner includes two parts, one part is the pressure drop caused by the air conditioner outdoor unit 11, and the other part is the pressure drop caused by the pipes, the total pipe pressure drop of the multi-split air conditioner system can be obtained by subtracting the outdoor unit pressure drop from the system total pressure drop.

[0075] In the step S4, the total pipe pressure drop of each air conditioner indoor unit 21 is related to the length of the pipe and the unit length of each section of the pipe. Therefore, the length of the multi-split pipe corresponding to each air conditioner indoor unit 21 can be calculated according to the unit length pressure drop and the total pipe pressure drop of the indoor unit connecting pipe 34, the total connecting pipe 32, and the branch pipe 33.

[0076] In conclusion, the technical solution of the present application can obtain the unit length pressure drop of the indoor unit connecting pipe 34, the unit length pressure drop of the outdoor unit connecting pipe 31, and the unit length pressure drop of the branch pipe 33, and calculate the corresponding length of the multi-connected pipe of each air conditioner indoor unit 21 according to the unit length pressure drop of the indoor unit connecting pipe 34, the unit length pressure drop of the outdoor unit connecting pipe 31, and the unit length pressure drop of the branch pipe 33. The present application can reduce the error in the measurement process and improve the accuracy of the obtained results, because the length of the multi-connected pipe of each air conditioner indoor unit 21 is obtained without using a length measuring tool. In addition, the length of the multi-connected pipe of each air conditioner indoor unit 21 is obtained according to the unit length pressure drop and the total pressure drop of the pipe, so that the reliability of the multi-connected air conditioner system can be ensured when the multi-connected air conditioner system is controlled according to the result.

[0077] In one embodiment, the process of obtaining the inner diameter of the branch pipe 33 in step S1, and obtaining the inner diameter and flow area of the outdoor unit connecting pipe 31, the indoor unit connecting pipe 34, and the total connecting pipe 32 is as shown in Figure 3

[0078] Step S101: Obtain the model of each air conditioner indoor unit 21 and the model of each air conditioner outdoor unit 11.

[0079] Step S102: Obtain the inner diameter and flow area of the outdoor unit connecting pipe 31, and the total capacity of the air conditioner outdoor unit 11 according to the model of each air conditioner outdoor unit 11.

[0080] Step S103: Obtain the inner diameter and flow area of the total connecting pipe 32 according to the total capacity of the air conditioner outdoor unit 11.

[0081] Step S104: Obtain the inner diameter and flow area of the indoor unit connecting pipe 34, and the capacity of each air conditioner indoor unit 21 according to the model of each air conditioner indoor unit 21.

[0082] Step S105: Obtain the inner diameter of the branch pipe 33 according to the capacity of each air conditioner indoor unit 21.

[0083] The models of each air conditioner indoor unit 21 in the indoor unit group can be the same or different, and the models of each air conditioner unit in the outdoor unit group can be the same or different. In step S101, the model of each air conditioner indoor unit 21 and the model of each air conditioner outdoor unit 11 can be obtained from the nameplate on each air conditioner indoor unit 21 and each air conditioner outdoor unit 11.

[0084] ​In the step S102, an air conditioner outdoor unit 11 data table can be established, in which the capacities of various types of air conditioner outdoor units 11, the inner diameters and flow areas of the corresponding outdoor unit pipes are stored. After the types of the air conditioner outdoor units 11 are obtained in the step S101, the air conditioner outdoor unit 11 data table is queried according to the types of the air conditioner indoor units 21 in the step S102, so that the inner diameters and flow areas of the corresponding outdoor unit pipes of the air conditioner outdoor units 11 and the capacities of the air conditioner outdoor units 11 are obtained. In the example, the capacity of the ith air conditioner outdoor unit 11 obtained is Q o,i , and the total number of the air conditioner indoor units 21 is N tot . The total capacity Q o of the air conditioner outdoor units 11 can be obtained by the following calculation formula:

[0085]

[0086] In the step S103, a total connection pipe 32 data table can be established, in which the inner diameters and flow areas of the total connection pipes 32 corresponding to the total capacities of the air conditioner outdoor units 11 are stored. After the total capacities of the air conditioner outdoor units 11 are obtained in the step S102, the total connection pipe 32 data table is queried according to the total capacities of the air conditioner outdoor units 11, so that the inner diameters and flow areas of the second pipes corresponding to the total capacities of the air conditioner outdoor units 11 are obtained.

[0087] In the step S104, an air conditioner indoor unit 21 data table can be established, in which the capacities of various types of air conditioner indoor units 21 and the inner diameters and flow areas of the corresponding indoor unit connection pipes 34 are stored. After the types of the air conditioner indoor units 21 are obtained, the air conditioner indoor unit 21 data table can be queried according to the types of the air conditioner indoor units 21, so that the capacities of the air conditioner indoor units 21 and the inner diameters and flow areas of the corresponding indoor unit connection pipes 34 are obtained.

[0088] In the step S105, a branch pipe 33 data table can be established, in which the inner diameters and flow areas of the branch pipes 33 corresponding to the average capacities of the air conditioner indoor units 21 are stored. After the capacities of the air conditioner indoor units 21 are obtained in the step S104, the average value of the capacities of the air conditioner indoor units 21 is calculated, and the branch pipe 33 data table is queried according to the average value, so that the inner diameter of the corresponding branch pipe 33 is obtained.

[0089] In an embodiment, the process of obtaining the unit length pressure drop of the total connection pipe 32 according to the inner diameter and flow area of the total connection pipe 32 in the step S2 is shown in Figure 4 , which includes:

[0090] Step S201: obtaining the system refrigerant flow, the refrigerant density and the friction factor of the total connection pipe 32;

[0091] Step S202: Obtaining the mass flow density of the main connecting pipe 32 based on the refrigerant flow rate of the system and the flow area of ​​the main connecting pipe 32;

[0092] Step S203 : Calculating the pressure drop per unit length of the main connecting pipe 32 according to the friction factor, mass flow density, and refrigerant density of the main connecting pipe 32 .

[0093] Assume that the friction factor of the main connecting pipe 32 obtained in step S201 is f C In the above step S212, the following calculation formula can be used: tot and the flow area A of the total connecting pipe 32 c , the mass flow density G of the total connecting pipe 32 is obtained c :

[0094]

[0095] In the above step S203, the following calculation formula can be used: according to the friction factor f of the main connecting pipe 32 C , mass flow density G of the total connecting pipe 32 c and refrigerant density ρ, calculate the pressure drop dP per unit length of the total connecting pipe 32 C :

[0096]

[0097] In one embodiment, the process of obtaining the pressure drop of the air conditioner outdoor unit 11 according to the internal unit and the flow area of ​​the outdoor unit connecting pipe 31 in the above step S2 is as follows: Figure 5 As shown, including:

[0098] Step S211: Obtaining the system refrigerant flow rate, the local resistance coefficient of the outdoor unit connecting pipe 31, and the density of the refrigerant;

[0099] Step S212: Obtaining an average mass flow density of the outdoor unit connecting pipe 31 based on the system refrigerant flow rate and the flow area of ​​the outdoor unit connecting pipe 31;

[0100] Step S213: Calculate the pressure drop of the air conditioner outdoor unit 11 according to the average mass flow density of the outdoor unit connecting pipe 31 , the local resistance coefficient of the outdoor unit connecting pipe 31 , and the density of the refrigerant.

[0101] Assume that the system refrigerant flow rate obtained in step S211 is m tot , the local resistance of the external unit connecting pipe is f f , the density of the refrigerant is ρ, then in the above step S202, the following calculation formula is used, according to the system refrigerant flow m tot The flow area A of the external unit connecting pipe 31 E , the average mass flow density G of the external machine connecting pipe 31 is obtainedE :

[0102]

[0103] In step S213, let the capacity of the i-th indoor unit 21 be Q i,i , then the average capacity Q i,ave of the indoor unit 21 can be calculated by the following formula:

[0104]

[0105] According to the average mass flow density G E of the outdoor unit connecting pipe 31, the local resistance coefficient f f and the density p of the refrigerant, the pressure drop AP of the outdoor unit 11 is obtained: odu :

[0106]

[0107] In one embodiment, the process of obtaining the unit length pressure drop of the indoor unit connecting pipe 34 according to the inner diameter and the flow area of the indoor unit connecting pipe 34 in step S2 is shown in Figure 6 , which includes:

[0108] Step S221: Obtain the system refrigerant flow, the friction factor of the indoor unit connecting pipe 34 and the refrigerant density;

[0109] Step S222: Obtain the total inner diameter and the total flow area of the indoor unit connecting pipe 34 according to the inner diameter and the flow area of each indoor unit connecting pipe 34;

[0110] Step S223: Obtain the mass flow density of the indoor unit connecting pipe 34 according to the system refrigerant flow and the total flow area of the indoor unit connecting pipe 34;

[0111] Step S224: Obtain the unit length pressure drop of the indoor unit connecting pipe 34 according to the friction factor, the total inner diameter, the mass flow density and the refrigerant density of the indoor unit connecting pipe 34.

[0112] As an example, in step S221, let the obtained friction factor of the indoor unit connecting pipe 34 be f A , in step S222, let the inner diameter of the i-th indoor unit connecting pipe 34 be d A,i , and the flow area of the i-th indoor unit connecting pipe 34 be A A,i , then the total inner diameter d A and the total flow area A A of the indoor unit connecting pipe are obtained by the following formula:

[0113]

[0114] In the above step S223, the system refrigerant flow rate m tot , the total flow area A A of the indoor unit connecting pipe 34 is obtained A :

[0115]

[0116] In the above step S224, the unit length pressure drop dP A of the indoor unit connecting pipe 34 is obtained according to the friction factor f A , the total inner diameter d A , the mass flow density G A , and the refrigerant density p by the following calculation formula:

[0117]

[0118] In one embodiment, the flow of obtaining the unit length pressure drop of the branch pipe 33 according to the inner diameter and the flow area of the branch pipe 33 in the above step S2 is shown in FIG. 8, which includes: Figure 7

[0119] Step S231: Obtain the number of the air conditioner indoor units 21 that are turned on.

[0120] Step S232: When the number of the air conditioner indoor units 21 that are turned on is one, obtain the unit length pressure drop of the branch pipe 33 according to the inner diameter and the unit length pressure drop of the indoor unit connecting pipe 34, and the inner diameter of the branch pipe 33.

[0121] Step S233: When the number of the air conditioner indoor units 21 that are turned on is more than one, obtain the unit length pressure drop of the branch pipe 33 according to the inner diameter and the unit length pressure drop of the indoor unit connecting pipe 34, the inner diameter of the branch pipe 33, and the number of the air conditioner indoor units 21 that are turned on.

[0122] As an example, assume that the number of the air conditioner indoor units 21 that are turned on obtained in the above step S231 is N; in the above step S232, when the number of the air conditioner indoor units 21 that are turned on is one, i.e., only one air conditioner indoor unit 21 is in the on state, the unit length pressure drop dP A of the branch pipe 33 is calculated according to the total inner diameter d B of the indoor unit connecting pipe 34, the inner diameter d A of the branch pipe 33, and the unit length pressure drop dP B of the indoor unit connecting pipe 34 by the following calculation formula:

[0123]

[0124] ​As an example, in the above step S233, when the number of the air conditioner indoor units 21 is multiple, the following calculation formula is used to obtain the unit length pressure drop of the branch pipe 33 according to the inner diameter of the indoor unit connecting pipe 34 and the unit length pressure drop, the inner diameter of the branch pipe 33, and the number of the air conditioner indoor units 21:

[0125]

[0126] In an embodiment, the process of calculating the corresponding connection pipe length of each air conditioner indoor unit 21 according to the unit length pressure drop of the indoor unit connecting pipe 34, the total connecting pipe 32 and the branch pipe 33, the preset length of each air conditioner indoor unit 21 and the total pipe pressure drop in the above step S4 is as shown in Figure 8 , which includes:

[0127] Step S401: obtaining the equivalent unit length pressure drop according to the unit length pressure drop of the total connecting pipe 32 and the unit length pressure drop of the branch pipe 33;

[0128] Step S402: calculating the uncertainty caused by each indoor unit connecting pipe 34 according to the unit length pressure drop of the indoor unit connecting pipe 34 and the equivalent unit length pressure drop;

[0129] Step S403: calculating the determined length of each indoor unit connecting pipe 34 according to the total pipe pressure drop, the preset length of each indoor unit connecting pipe 34, the unit length pressure drop of the indoor unit connecting pipe 34 and the equivalent unit length pressure drop;

[0130] Step S404: calculating the corresponding connection pipe length of each air conditioner indoor unit 21 according to the uncertainty caused by each indoor unit connecting pipe 34 and the determined length of each indoor unit connecting pipe 34.

[0131] As an example, in the above step S401, there is a difference between the unit length of the outdoor unit total collecting pipe and the branch pipe 33. In this embodiment, the unit length pressure drop of the total connecting pipe 32 and the unit length pressure drop of the branch pipe 33 are converted to obtain the unit length pressure drop that can be applied to the outdoor unit total collecting pipe and the branch pipe 33, i.e. the equivalent unit length pressure drop, so as to reduce the complexity of the calculation.

[0132] As an example, assuming that the equivalent unit length pressure drop obtained in the above step S401 is dP, in the above step S402, the following calculation formula is used to obtain the uncertainty ΔL caused by the indoor unit connecting pipe 34 according to the unit length pressure drop of the indoor unit connecting pipe 34 and the equivalent unit length pressure drop, and the uncertainty length ΔL A of the indoor unit connecting pipe 34. A In this example, the value of the uncertainty length ΔL

[0133]

[0134] As an example, assume that the preset length of the indoor pipe corresponding to one of the air conditioner indoor units 21 is L A , then in the above step S403, the following calculation formula is used to calculate the determined length L of the indoor unit connecting pipe 34 corresponding to the indoor unit 21 of the air conditioner A0 :

[0135]

[0136] Then obtain the preset length L of the indoor pipe corresponding to the indoor unit 21 of the air conditioner A and calculated length L A0 The size relationship between them is obtained, and based on the size relationship, the determined length of the total piping of the air conditioner indoor unit 21 is obtained:

[0137] When the air conditioner indoor unit 21 corresponds to the preset length L of the indoor unit piping A Not greater than its calculated length L A0 When the air conditioner indoor unit 21 corresponds to the calculated length L of the indoor pipe, A0 As the determined length L of the total piping of the air conditioner indoor unit 21, in this example, the value of L can be 5.5, that is, L=L A0 ;

[0138] When the air conditioner indoor unit 21 corresponds to the preset length L of the indoor unit piping A Greater than its calculated length L A0 The total pipe length L of the air conditioner indoor unit 21 is calculated by the following formula:

[0139]

[0140] As an example, in the above step S404, the sum of the determined total piping length L corresponding to the air conditioner indoor unit 21 and the uncertainty ΔL caused by the assumption of the indoor unit connection can be used as the online piping length L corresponding to the air conditioner indoor unit 21. t :

[0141] L t =L+ΔL

[0142] In one embodiment, the calculation of the equivalent pressure drop per unit length in step S401 based on the pressure drop per unit length of the main connecting pipe 32 and the pressure drop per unit length of the branch pipe 33 includes:

[0143] First, obtain the weight value of the main connecting pipe 32 and the weight value of the branch pipe 33;

[0144] Then, the pressure drop per unit length of the main connecting pipe 32 and the pressure drop per unit length of the branch pipe 33 are weightedly calculated according to the weight of the main connecting pipe 32 and the weight of the branch pipe 33 to obtain the above-mentioned equivalent length pressure drop.

[0145] As an example, the weight values ​​of the main connecting pipe 32 and the branch pipe 33 can be set by the staff according to the actual application scenario. In this example, the weight value of the main connecting pipe 32 is set to A, and the weight value of the branch pipe 33 is set to B. In this example, the following calculation formula can be used to perform weighted calculation on the unit length pressure drop of the main connecting pipe 32 and the unit length pressure drop of the branch pipe 33 to obtain the equivalent length pressure drop:

[0146] dP=A·dP B +B·dP C

[0147] The present invention also provides a pipe length identification device for a multi-split air conditioning system, such as Figure 9 As shown, the device includes a processor, a memory, a communication interface and a communication bus, and the processor, the memory and the communication interface communicate with each other through the communication bus. The processor is used to provide computing and control capabilities. The memory includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and computer program instructions. The internal memory provides an environment for the operation of the operating system and computer program instructions in the non-volatile storage medium. The communication interface of the above-mentioned device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be achieved through WIFI, an operator network, NFC (near field communication) or other technologies. The piping length identification device of the multi-split air-conditioning system provided in this embodiment has a memory for storing computer program instructions. When the computer program instructions are executed by the processor, multiple embodiments of the piping length identification method of the above-mentioned multi-split air-conditioning system can be implemented.

[0148] The application further provides a computer readable storage medium. A person skilled in the art can understand that all or part of the processes in the above-mentioned embodiments of the method for identifying the pipe length of the multi-connected air conditioning system can be completed by computer program instructions instructing related hardware, and the computer program instructions can be stored in a non-volatile computer readable storage medium. When the computer program instructions are executed, the processes of the above-mentioned embodiments can be included. Any reference to the memory, storage, database or other medium used in each embodiment of the application can include non-volatile and / or volatile memory. The non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. The volatile memory can include random access memory (RAM) or external cache memory. As an illustration but not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM) and memory bus dynamic RAM (RDRAM), etc.

[0149] At this point, those skilled in the art will appreciate that although the present application has been shown and described in detail with respect to a number of exemplary embodiments, various substitutions and modifications can be made thereto without departing from the spirit and scope of the application as defined by the appended claims. Therefore, the scope of the present application should be limited only by the appended claims.

Claims

1. A method of recognizing lengths of pipes of a multi VRF air conditioning system, the multi VRF air conditioning system including an air conditioning outdoor unit, an air conditioning indoor unit, and a pipe system connecting the air conditioning outdoor unit and the air conditioning indoor unit. The piping system includes: An outdoor unit connecting pipe connected to the outdoor unit of the air conditioner, a main connecting pipe communicating with the outdoor unit connecting pipe, a branch pipe connected to the main connecting pipe, and an indoor unit connecting pipe connected to the branch pipe and the indoor unit of the air conditioner; wherein the piping length identification method comprises: Obtaining the inner diameter of the branch pipe, and obtaining the inner diameters and flow areas of the external unit connecting pipe, the internal unit connecting pipe, and the main connecting pipe; Obtaining the pressure drop of the outdoor unit of the air conditioner according to the inner diameter and flow area of ​​the outdoor unit connecting pipe; Obtaining a pressure drop per unit length of the internal machine connecting pipe according to the inner diameter and flow area of ​​the internal machine connecting pipe; Obtaining a pressure drop per unit length of the main connecting pipe according to the inner diameter and flow area of ​​the main connecting pipe; Calculating the pressure drop per unit length of the branch pipe based on the inner diameter and the pressure drop per unit length of the internal unit connecting pipe and the inner diameter of the branch pipe; Obtaining a total system pressure drop of the multi-split air-conditioning system, and obtaining a total pipeline pressure drop of the multi-split air-conditioning system based on the total system pressure drop of the multi-split air-conditioning system and the pressure drop of the air-conditioning outdoor unit; Obtaining the preset length of the air conditioner indoor unit, and calculating the online piping length corresponding to the air conditioner indoor unit based on the unit-connecting pipe, main connecting pipe, and branch pipe pressure drops per unit length, the preset length of each air conditioner indoor unit, and the total pipe pressure drop; Calculating the online piping length corresponding to the air conditioner indoor unit based on the unit length pressure drop of the indoor unit connecting pipe, the main connecting pipe and the branch pipe, the preset length of each air conditioner indoor unit and the total pipe pressure drop includes: Obtaining an equivalent pressure drop per unit length based on the pressure drop per unit length of the main connecting pipe and the pressure drop per unit length of the branch pipe; The uncertainty caused by the assumption of the internal unit connecting pipe is calculated based on the pressure drop per unit length of the internal unit connecting pipe, the equivalent pressure drop per unit length, and the uncertain length of the internal unit connecting pipe. The uncertainty caused by the assumption of the internal unit connecting pipe is: where ΔL is the uncertainty caused by the inner machine connecting pipe, dP A is the unit length pressure drop of the inner machine connecting pipe, dP is the equivalent unit length pressure drop, ΔL A is the uncertain length of the inner machine connecting pipe; Calculate the determined length of each internal unit connecting pipe according to the total pressure drop of the pipeline, the preset length of the internal unit connecting pipe, the unit pressure drop of the length of the internal unit connecting pipe, and the equivalent unit pressure drop; Based on the uncertainty caused by the assumption of the indoor unit connection pipe corresponding to each air conditioner indoor unit and the determined length of each indoor unit connection pipe, calculate the online piping length corresponding to each air conditioner indoor unit.

2. The method of claim 1, wherein the method further comprises: determining a length of a pipe connected to the outdoor unit based on the number of the outdoor units. The obtaining of the inner diameter of the branch pipe, and the inner diameters and flow areas of the external unit connecting pipe, the internal unit connecting pipe, and the main connecting pipe include: Obtain the model of the indoor unit of the air conditioner and the model of the outdoor unit of the air conditioner; Obtaining the inner diameter and flow area of ​​the total connecting pipe and the total capacity of the air conditioner outdoor unit according to the model of the air conditioner outdoor unit; Obtaining the inner diameter and flow area of ​​the total connecting pipe according to the total capacity of the air conditioner outdoor unit; According to the model of the air conditioner indoor unit, the inner diameter and flow area of ​​the indoor unit connecting pipe and the capacity of the air conditioner indoor unit are obtained; The inner diameter of the branch pipe is obtained according to the capacity of the air conditioner indoor unit.

3. The method of claim 1, wherein the method further comprises: determining a length of a pipe connected to the outdoor unit based on the number of the outdoor units. The step of obtaining the pressure drop of the outdoor unit of the air conditioner according to the inner diameter and flow area of ​​the outdoor unit connecting pipe comprises: Obtaining the system refrigerant flow rate, the local resistance coefficient of the outdoor unit connecting pipe, and the refrigerant density; According to the system refrigerant flow and the through-flow area of the outdoor unit connecting pipe, an average mass flow density of the outdoor unit connecting pipe is obtained; According to the average mass flow density, the local resistance coefficient and the density of the refrigerant of the outdoor unit connecting pipe, a pressure drop of the air conditioner outdoor unit is obtained.

4. The method of claim 1, wherein the method further comprises: determining a length of a pipe connected to the outdoor unit based on the number of the outdoor units. The obtaining of the unit length pressure drop of the indoor unit connecting pipe according to the inner diameter and the through-flow area of the indoor unit connecting pipe comprises: The system refrigerant flow, the refrigerant density and the friction factor of the indoor unit connecting pipe are obtained; The total inner diameter and the total through-flow area of the indoor unit connecting pipe are obtained according to the inner diameter and the through-flow area of each indoor unit connecting pipe; The mass flow density of the indoor unit connecting pipe is obtained according to the system refrigerant flow and the total through-flow area of the indoor unit connecting pipe; The unit length pressure drop of the indoor unit connecting pipe is obtained according to the friction factor, the total inner diameter, the mass flow density and the refrigerant density of the indoor unit connecting pipe.

5. The method of claim 1, wherein the method further comprises: determining a length of a pipe of the multi VRF air conditioning system based on the determined number of the indoor units. The obtaining of the unit length pressure drop of the total connecting pipe according to the inner diameter and the through-flow area of the total connecting pipe comprises: The system refrigerant flow, the refrigerant density and the friction factor of the total connecting pipe are obtained; The mass flow density of the total connecting pipe is obtained according to the system refrigerant flow and the through-flow area of the total connecting pipe; The unit length pressure drop of the total connecting pipe is calculated according to the friction factor, the inner diameter, the mass flow density and the refrigerant density of the total connecting pipe.

6. The method of claim 1, wherein the method further comprises: determining a length of a pipe of the multi VRF system based on the determined number of the indoor units. The obtaining of the unit length pressure drop of the branch pipe according to the inner diameter of the indoor unit connecting pipe, the unit length pressure drop and the inner diameter of the branch pipe comprises: The number of the air conditioner indoor units that are turned on is obtained; When the number of the air conditioner indoor units that are turned on is one, the unit length pressure drop of the branch pipe is obtained according to the inner diameter, the unit length pressure drop of the indoor unit connecting pipe and the inner diameter of the branch pipe; When the number of the air conditioner indoor units that are turned on is more than one, the unit length pressure drop of the branch pipe is obtained according to the inner diameter, the unit length pressure drop of the indoor unit connecting pipe, the inner diameter of the branch pipe and the number of the air conditioner indoor units that are turned on.

7. The method of claim 1, wherein the method further comprises: determining a length of a pipe connected to the outdoor unit based on the number of the outdoor units. The obtaining of the equivalent unit length pressure drop according to the unit length pressure drop of the total connecting pipe and the unit length pressure drop of the branch pipe comprises: The weight of the total connecting pipe and the weight of the branch pipe are obtained; The unit length pressure drop of the total connecting pipe and the unit length pressure drop of the branch pipe are weighted according to the weight of the total connecting pipe and the weight of the branch pipe, so as to obtain the equivalent unit length pressure drop.

8. A piping length recognition device of a multi VRF air conditioning system, characterized by, The computer readable storage medium stores computer program instructions, and when the computer program instructions are executed by the processor, the multi-split air conditioning system pipe length identification method according to any one of claims 1-7 is realized.

9. A computer-readable storage medium, characterized in that, The computer readable storage medium stores computer program instructions, and when the computer program instructions are executed by the processor, the multi-split air conditioning system pipe length identification method according to any one of claims 1-7 is realized.

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